Toi Dien Giao An

GV:NGUYN THANH TINgy son: 25-07 PPCT : 01

NM HC:2011-2012

Bi 1: TIU CHUN TRNH BY BN V K THUTI. MC TIU 1. Kin thc: Hc sinh hiu c ni dung c bn ca mt s tiu chun v trnh by bn v k thut. 2. K nng: Thc hin cc thao tc thnh tho vi nhng tiu chun bn v k thut. 3. Thi : C thc trong vic thc hin cc tiu chun bn v k thut. CHUN B 1 Chun b ca gio vin: + Nghin cu SGK v SGV. + c cc Tiu chun Vit Nam v cc Tiu chun Quc t v trnh by bn v k thut. + Tranh v cc hnh: 1.3, 1.4, v 1.5 SGK. 2 Chun b ca hc sinh: n tp phn v k thut lp 8. CC BC LN LP 1. n nh: n nh t chc lp. (2 pht) 2. Kim tra: Gii thiu mc ch, yu cu ca b mn cng ngh lp 11. (3 pht) 3. Bi mi: Ni dung c bn Hot ng thy tr H 1: Tm hiu ngha ca tiu chun bn v k thut. GV: V sao ni bn v k thut l ngn ng chung dng trong k thut? HS: Da vo kin thc hc lp 8, suy ngh v tr li cu hi. GV: Bn v k thut c xy dng trn quy tc no? HS: Tr li cu hi. I . KH GIY H 2: Gii thiu kh giy. - TCVN quy nh kh giy ca cc bn GV: V sao bn v phi v trn cc kh giy nht nh? v k thut, gm cc kh giy chnh: A0, HS: Tr li cu hi. A1, A2, A3, A4 (bng 1.1 SGK) GV: Vic quy nh kh giy c lin quan g n cc thit - Cc kh giy chnh c lp ra t kh b sn xut v in n? giy A0. HS: Tr li cu hi. - Mi bn v u c khung v v khung GV: Kt lun: Quy nh kh giy thng nht qun l v tn (H1.2) tit kim trong sn xut. II . T LE GV: Yu cu HS quan st hnh 1.1 v bng 1.1 - T l l t s gia kch thc o c HS: Quan st hnh v v bng 1.1 trong SGK. trn hnh biu din v kch thc thc GV: Cc kh giy c mi quan h khng? Cch chia cc tng ng trn vt th . kh giy nh th no? (Gi : chia t kh giy A0). - C ba loi t l: thu nh, nguyn hnh, HS: Tr li cu hi. phng to. GV: Trnh by cch chia kh giy A0 c din tch 1m2 III . NT V thnh cc kh giy chnh. 1 . Cc loi nt v: nt lin m, nt H 3: Gii thiu t le lin mnh, nt ln sng, nt t mnh, GV: Th no l t l ca bn v? nt gch chm mnh. (bng 1.2 SGK) HS: Da vo kin thc v ton hc v c cc bn a l 2 . Chiu rng ca nt v: nt m tr li cu hi. bng 0,5mm v nt mnh bng 0,25mm. GV: a ra kt lun v yu cu HS c phn t l theo TCVN 7286 : 2003 ( ISO 5455 : 1971) trong SGK. H 4: Gii thiu nt v 1

II.

III.

TL 10ph

5ph

5ph

GV:NGUYN THANH TITL Ni dung c bn

NM HC:2011-2012Hot ng thy tr GV: Yu cu HS xem bng 1.2 v hnh v phng to 1.3 trn bng. HS: Quan st hnh v 1.3 v bng 1.2 trong SGK. GV: Cc nt lin m, lin mnh, nt t, nt gch chm mnh biu din cc ng g ca vt th? HS: Tr li cu hi. GV: Yu cu HS quan st dy quy nh b rng nt v. GV: Vic quy nh b rng ca nt v c lin quan g n bt v? HS: Tr li cu hi. GV: Quy nh b rng nt v to thun li cho vic ch to v s dng bt v. GV: Trnh by cch v cc loi nt v nh SGK. H 5: Gii thiu ch vit GV: Trn bn v k thut, ngoi cc hnh v cn c phn ch ghi cc kch thc, k hiu, cc ch thch cn thit. Vy yu cu ch vit trn bn v k thut nh th no? HS: Tr li cu hi. GV: Ch vit c quy nh theo TCVN 7284 2 : 2003 (ISO 3092 2 : 2000). GV: Yu cu HS quan st hnh v 3.4 v c nhn xt g v kiu dng, cu to v kch thc cc phn t ca ch. HS: Quan st hnh v v a ra nhn xt. H 6: Gii thiu cch ghi kch thc GV: Ti sao phi ghi kch thc ca cc hnh v? GV: Vic ghi sai kch thc hoc gy nhm ln cho ngi c th s nh th no? HS: Tr li cu hi. GV: Trnh by cc quy nh v ghi kch thc. HS: Theo di v ghi chp. GV: Chiu ca ch s kch thc trong trng hp ng kch thc c chiu nghing khc nhau c vit nh th no? GV: Yu cu HS nhn xt mt s kch thc ghi hnh 1.6 v 1.7 SGK. HS: a ra nhn xt. H 7: Cng c, giao nhim v v nh. GV: V sao bn v k thut phi c lp theo cc tiu chun? GV: Tiu chun trnh by bn v k thut gm nhng tiu chun no? Giao nhim v v nh: + Tr li cc cu hi t 1 n 5 trang 10 SGK. + Lm bi tp 1 v 2 trang 10 SGK. +c trc bi 2-Hnh chiu vung gc.

IV . CH VIT 1 . Kh ch: kh ch (h) c xc nh 5ph bng chiu cao ca ch hoa tnh bng mm. C cc kh ch sau: 1,8; 2,5; 3,5; 5; 7; 10; 14; 20mm. chiu rng (d) ca 1 h. nt ch thng ly bng 10 2 . Kiu ch: (hnh 1.4) V . GHI KCH THC 1 . ng kch thc: c v bng 10ph nt lin mnh, song song vi phn t c ghi kch thc, u mt ng kch thc c v mi tn (hnh 1.5). 2 . ng ging kch thc: c v bng nt lin mnh, thng k vung gc v vt qu ng kch thc khong 2 4mm. 3 . Ch s kch thc: l tr s kch thc thc, khng ph thuc vo t l bn v v thng c ghi trn ng kch thc. -Kch thc di dng n v mm, 5ph trn bn v khng ghi n v o (hnh 1.6 SGK), nu dng n v di khc mm th phi ghi r n v o. -Kch thc gc dng n v o l , pht, giy. (cch ghi nh hnh 1.7 SGK). 4 . K hiu , R: trc con s kch thc ng knh ca ng trn ghi k hiu v bn knh ca cung trn ghi k hiu R. (hnh 1.5).

IV. RT KINH NGHIM-B SUNG 2


NM HC:2011-2012

Bi 2: HNH CHIU VUNG GCI.Mc tiu: Dy xong bi ny GV cn lm cho HS: - Hiu c ni dung c bn ca phng php hnh chiu vung gc - Bit c v tr ca cc hnh chiu trn bn v II.Chun b bai ging: GV: -Tranh v phng to hnh 2.1, 2.2, 2.3 v 2.4 sgk -Vt mu theo hnh 2.1 sgk v m hnh ba mt phng hnh chiu HS: n tp phng php chiu gc th nht hc phn v k thut Cng Ngh 8 III.Tin trnh dy hc: Thi lng Ni dung bi hc Hot ng ca thy v tr 15 I.Phng php chiu gc th nht (PPCG1): Hot ng 1: Tm hiu phng php - Vt th c t trong mt gc to thnh bi hnh chiu gc th nht cc mt phng hnh chiu . Mt phng hnh Ni dung ny HS hc lp 8 nn GV chiu ng pha sau, mt phng hnh chiu ch t cc cu hi hc sinh nh li ni bng pha di, mt phng hnh chiu cnh dung ca PPCG1 bn phi vt th. - Trong PPCG1 , vt th c t - Sau khi chiu vt th ln cc mt phng hnh nh th no i vi cc mt phng chiu ,mt phng hnh chiu bng c xoay hnh chiu ng bng v cnh ? xung di 900 v mt phng hnh chiu cnh - Yu cu HS xc nh mt phng xoay sang phi 900 cc hnh chiu cng nm hnh chiu ng , cnh v bng? trn mt phng hnh chiu ng - Sau khi chiu mt phng hnh -Trn bn v: chiu bng v cnh c xoay nh + Hnh chiu bng t di hnh chiu ng th no? + Hnh chiu cnh t bn phi hnh chiu ng - Trn bn v cc hnhchiuc b tr nh th no? 20 II.Phng php chiu gc th ba (PPCG3): -Vt th c t trong mt gc to bi ccmt phng hnh chiu .Mt phng hnh chiu ng trc , mt phng hnh chiu bng trn vmt phng hnh chiu cnh bn tri vt th -Sau khi chiu vt th ln cc mt phng hnh chiu ,mt phng hnh chiu bng c xoay ln 900 v mt phng hnh chiu cnh xoay sang tri 900 cc hnh chiu cng nm trn mt phng hnh chiu ng -Trn bn v: +Hnh chiu bng t trn hnh chiu ng +Hnh chiu cnh t bn tri hnh chiu ng 3 Hot ng 2:Tm hiu phng php chiu gc th ba: -GV dng m hnh ba mt phng hnh chiu gii thiu cho HS bit cch t vt th trong PPCG3 -Yu cu HS xc nh ba mt phng hnh chiu trn tranh v? - - Sau khi chiu mt phng hnh chiu bng v cnh c xoay nh th no? - Trn bn v cc hnhchiuc b tr nh th no? - GV cho bit VN s dng PPCG1 cn chu M v mt s nc khc s dung PPCG3

GV:NGUYN THANH TI7

NM HC:2011-2012Hot ng 3: Cng c GV t mt s cu hi cng c v m rng kin thc: -V sao phi dng nhiu hnh chiu biu din vt th? -S khc nhau ca PPCG1 v PPCG3 nh th no? -Hng dn HS tr li cc cu hi v bi tp trong sgk

IV: RT KINH NGHIM-B SUNG

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NM HC:2011-2012

Bi 3: THC HNH V CC HNH CHIU CA VT TH N GINI, MC TIU BI DY - Hc sinh bit c khi nim c bn v mt h thng v bng my tnh. - hc sinh bit khi qut v phn mm AutoCAD. II, CHUN B BI GING 1, Chun b ni dung - Nghin cu k bi 13 SGK - Nghin cu s dng phn mm AutoCAD v c bn v ba chiu n gin v xy dng c vt th ba chiu n gin. - Tham kho thm ti liu lin quan. 2, Chun b dng dy hc - Hnh v 13.1 n 13.5 SGK - Mtvi bn v k thut bng my tnh v d minh ho. III, TIN TRNH BI DY 1, On nh lp, kim tra s s [1`] 2, Kim tra bi c [4`] 3, Nghin cu kin thc mi [35`]T/L NI DUNG BI HC PHNG PHP DY - HC

I, KHI NIM CHUNG Ngy nay, trong thi i cng ngh thng tin, cc bn v k thut c lp vi s tr gip ca my tnh. Vi cc u im: -Bn v c lp mt cch chnh xc v nhanh chng: -D dng sa cha, b sung, thay i, lu tr . -Gii phng con ngi ra khi cng vic nng nhc v trnh n iu.

Hot ng 1: Gii thiu chung Trc y ngi ta s dng cc dng c v nh bt ch, thc, compa, ke lp bn v k thut. Ngy nay, trong thi i cng ngh thng tin, cc bn v k thut c lp vi s tr gip ca my tnh vi cc u im l bn v c lp mt cch chnh xc v nhanh chng; d dng sa cha, b sung, thay i, lu tr; gip cho con ngi lm vic mt cch nh nhn v khng n iu trong khi lp bn v.

II, KHI QUT V H THNG Hot ng 2: Tm hiu khi qut v h thng v k V K THUT BNG MY TNH thut bng my tnh (h thng CAD) Cc h thng CAD xut hin vo khong gia nm 1960 v c p dng ngy cng rng ri trong cc lnh vc thit k GV:Em hy k mt vi lnh vc thit k m cn n bn v k thut? HS: tr li: GV: kt lun H thng CAD gm c hai phn: phn cng, phn mm. 5

GV:NGUYN THANH TI

NM HC:2011-2012

1, Phn cng L t hp cc phng tin k thut gm my tnh v cc thit b a thng tin vo v ra. GV: s dng hnh 13.1 gii thiu cho HS GV: cc thit b no dng a thng tin vo v xut thng tin ra? * HS nhn tranh v tr li * GV gii thch r cng dng ca tng thit b 2, Phn mm Phn mm ca h thng CAD m bo thc hin cc hot ng thnh lp bn v k thut nh: -To ra cc i tng v: ng thng, ng trn, ng cong, mt cong, vt th ba chiu, ; -Gii cc bi ton dng hnh v v hnh; -Xy dng cc hnh chiu vung gc, hnh ct, mt ct; -Xy dng cc loi honh chiu truch o, hnh chiu phi cnh; -T, v k hiu mt ct vt liu; -Ghi kch thc; *GV: dng hnh 13.2 SGK gii thiu cho HS: to ra cc i tng v th ta phi ra lnh cho my tnh thc hin (nu c my tnh th thc hin v mt vi hnh hc n gin cho HS xem). * Cc thit b phn cng, cc chng trnh phn mm d c hin i n v hon thin n au cng khng th thay oc ht mi hot ng tr tu ca con ngi. iu quyt nh trong v k thit k vn III, KHI QUT V PHN MM l kin thc v nng lc ca ngi s dng.AUTOCAD

1, Bn v hai chiu Phn mm AutoCAD p ng oc mi yu cu ca hot ng +v truyn thng trn mt phng hai chiu. 2, M hnh vt th ba chiu AutoCAD c kh nng to ra m hnh vt th trong khng gian ba chiu ca cc i tng cn thit k, sau t ng xy dng bn v cc hnh chiu, hnh ct, mt ct,trn mt phng hai chiu t m hnh vt th ba chiu.

* Hot ng 3: Tm hiu khi qut v phn mm AutoCAD. * GV gii thiu chung v phn mm (ging trong SGK). c bit c cc kh nng c bn sau: - Lp bn v hai chiu trn mt phng ging nh v truyn thng bng dng c v.(GV s dng hnh 13.3 SGK gii thiu cho HS xem hoc nu c my tnh biu din cho HS xem) * GV s dng hnh v 13.4 v 13.5 SGK minh ho (nu c my tinh th thc hin v mt vi hnh khi n gin) xy dng m hnh vt th cn thit k xut pht t cc vt th n gin nht gi l cc khi hnh hc c bn, khi hp, khi cu, khi nm, khi nn, khi 6

GV:NGUYN THANH TI

NM HC:2011-2012tr v khi xuyn. Sau lin kt cc khi li vi nhau bng nhiu cch to nn vt th cn thit k. Sau khi to xong vt th cn thit k, ta ra lnh cho AutoCAD t ng xy dng cc loi hnh chiu vung gc (nh trong bi thc hnh s 3 HS lm), (trc o, phi cnh) trn mt phng, cc loi hnh ct, mt ct,(ging nh trong bi thc hnh s 6) theo yu cu ca ngi s dng v b tr cc hnh chiu ny ln mt bn v.

* Hot ng 4: Tng kt, nh gi +Ti sao cn phi lp bn v bng my tnh ? +Nu cc thnh phn ca mt h thng CAD v cc nhim v ca chng ? +Phn mm AutoCAD c th thc hin c cc cng vic g? Theo em cng vic g l mi v th v ? HS tr li, GV nhn xt, b sung, nh gi v cho im. Tng kt kin thc trng tm ca bi. Yu cu HS v nh hc bi c v tr li cc cu hi cui bi trong SGK, HS c trc bi 14. IV: RT KINH NGHIM-B SUNG

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NM HC:2011-2012

Bi 4: MT CT V HNH CTI. MC TIU. 1. Kin thc: Hc xong bi ny GV cn lm cho HS: - Hiu c mt s kin thc v mt ct v hnh ct. - Phn bit c mt ct chp v mt ct ri. iu c mt s dng hnh ct. 2. K nng: - Bit cch v mt ct v hnh ct ca vt th n gin. 3. Thi : - C hng th hc tp. II. CHUN B: 1. Chun b ca Gio Vin: - Nghin cu k bi 4 SGK, SGV, ti liu lin quan. - M hnh, vt mu, tranh v phng to cc hnh 4.1; 4.2; 4.3; 4.4; 4.5; 4.6; v 4.7 SGK. 2. Chun b ca hc sinh: - n li kin thc lin quan v hnh ct hc phn v k thut ca Cng Ngh 8. -c trc nh bi 4 SGK. - Hon thnh mu bo co thc hnh bi 3. III. CC BC LN LP. 1. n nh lp: GV kim tra s s hc sinh. 2. Tin trnh bi dy: a. Cu trc v phn b bi ging: + Gm 3 ni dung chnh: - Khi nim v mt ct v hnh ct. - Mt ct. - Hnh ct. + Trng tm ca bi: - Khi nim v mt ct v hnh ct. - Cch v cc loi mt ct v cc loi hnh ct khc nhau. b. Hot ng dy hc: B sung Ni dung c bn Hot ng ca thy v tr 1. Hot ng 1: Tm hiu khi nim v mt ct v hnh ct. - Trong phn V K Thut ca CN 8, HS c hc v khi nim hnh ct v vy GV t cu hi gi HS nh li kin thc. Kt hp thng tin SGK v kin thc m HS hc GV t cu hi: Khi nim mt ct: Mt ct l hnh biu -Cu hi 1: Trng hp no th dng mt ct v din cc ng bao ca vt th nm trn mt hnh ct? phng ct. -HSTL: i vi nhng vt th c nhiu phn rng bn trong nh l, rnh, ... Cu hi 2: Trn cc bn v k thut, mt ct v hnh ct dng lm g? -HSTL: biu din hnh dng v cu to bn trong ca vt th (v nu dng hnh chiu biu din th hnh v c nhiu nt t, lm cho bn v khng r rng...) GV dng vt mu v hnh v phng to hnh 4.1 8

GV:NGUYN THANH TIKhi nim hnh ct: Hnh ct l hnh biu din mt ct v cc ng bao ca vt th sau mt phng ct.

NM HC:2011-2012SGK v hng dn HS qu trnh v mt ct v hnh ct, ch r cho HS bit hnh ct v mt ct ca vt th. GV hi: Mt phng ct dng lm g? HSTL: GV hi: Mt ct ca vt th nm u? HSTL: Nm trn mt phng ct(trc) Vy, th no l mt ct? Sau khi mt s HS tr li, GV chun li kin thc(nu sai) v cho HS ghi v. GV hi: Hnh ct ca vt th nm u? HSTL: Nm trn mt phng hnh chiu( l mt phng // vi mt phng ct.) Vy, th no l hnh ct? Sau khi mt s HS tr li, GV chun li kin thc(nu sai) v cho HS ghi v. GV: tm hiu cng dng v phn loi ca mt ct ta sang mc II. 2. Hot ng 2: Tm hiu v mt ct. Yu cu mt HS nhc li khi nim mt ct? Hi: mt ct dng lm g? HSTL: GV chi mt ct ca vt th trn hnh 4.1 v 4.2 SGK. Hi: C my loi mt ct? Gm nhng loi no? HSTL: c 2 loi mt ct l: -Mt ct chp. -Mt ct ri. GV treo tranh v phng to hnh 4.3 v ch cho HS bit mt ct chp ca vt th. Hi:Th no l mt ct chp? Dng trong trng hp no? Cch v nh th no? HSTL:

Cng dng ca mt ct: Mt ct dng biu din hnh dng tit din vung gc ca vt th.

1. Mt ct chp: Mt ct chp c v ngay ln hnh chiu tng ng, ng bao ca mt ct chp c v bng nt lin mnh. Mt ct chp dng biu din mt ct c hnh dng n gin. 2. Mt ct ri: Mt ct ri c v ngoi hnh chiu, ng bao ca mt ct ri c v bng nt lin m. Mt ct ri c t gn hnh chiu tng ng v lin h vi hnh chiu bng nt gch chm mnh. III. Hnh ct. Theo cu to ca vt th, hnh ct c chia lm ba loi: -Hnh ct ton b. -Hnh ct mt na. 9

GV treo tranh v phng to hnh 4.4 v ch cho HS bit mt ct ri ca vt th. Hi: Th no l mt ct ri? Dng trong trng hp no? Cch v nh th no?

3. Hot ng 3: Tm hiu v hnh ct. Yu cu HS nhc li khi nim hnh ct? Hi: Theo cu to ca vt th th hnh ct c chia lm my loi? l nhng loi no? GV treo tranh v phng to hnh 4.5 v hng dn

GV:NGUYN THANH TI-Hnh ct cc b. 1. Hnh ct ton b. Hnh ct ton b l hnh ct s dng mt mt phng ct v dng biu din hnh dng bn trong ca vt th. 2. Hnh ct mt na. Hnh ct mt na l hnh biu din gm mt na hnh ct ghp vi mt na hnh chiu, ng phn cch l trc i xng v bng gch chm mnh. Hnh ct mt na dng biu din vt th i xng. 3. Hnh ct cuc b: Hnh ct cc b l hnh biu din mt phn vt th di dng hnh ct, ng gii hn phn hnh ct v bng nt ln sng.

NM HC:2011-2012HS v hnh ct ton b. Hi: Th no l hnh ct ton b? Nu cng dng ca n? HSTL: GV treo tranh v phng to hnh 4.6 v hng dn HS v hnh ct mt na. Hi: Th no l hnh ct mt na? Nu cng dng ca n?

GV treo tranh v phng to hnh 4.7 v hng dn HS v hnh ct cc b. Hi: Th no l hnh ct cc b? Nu cng dng ca n? 4. Hot ng 4: Vn dng cng c hng dn v nh. Yu cu HS nhc li khi nim mt ct, hnh ct? Phn loi, cng dng v cch v cc loi mt ct v hnh ct? Hng dn HS lm bi tp SGK Gi HS c phn thng tin cui bi. V nh hc bi, lm bi tp cn li SGK, c trc bi 5 SGK

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GV:NGUYN THANH TINgy son:23-08 PPCT : 05

NM HC:2011-2012

Bi 5: HNH CHIU TRC OI. MC TIU Dy xong bi ny gio vin cn lm cho hc sinh: - Hiu c khi nim hnh chiu trc o - Bit cch v hnh chiu trc o ca vt th n gin II. CHUN B BI GING 1. Chun b ni dung - Nghin cu bi 5 SGK - c ti liu tham kho liu quan n bi ging 2. Chun b dng dy hc - Tranh v phng to hnh 5.1,3.9 SGK - Khun v elp (palet) III. TIN TRNH BI DY Bc 1: T chc lp: kim tra s s, n nh lp (1 pht) Bc 2: Kim tra bi c (4 pht) Bc 3: Nghin cu kin thc mi (35 pht)B sung Ni dung bi hc Hot ng ca gio vin hc sinh

I. KHI NIM 1. Th no l hnh chiu trc o a. Khi nim

b. Cch xy dng hinyhc chiu trc o

2. Thng s c bn ca hnh chiu trc o a. Gc trc o - Trc o l g ? - Gc trc o ?

- Hot ng 1: Tm hiu v khi nim hnh chiu trc o gv: Treo tranh 3.9 ln bng ch cho hc sinh l hnh chiu trc o ca cc vt th, t hi hc sinh th no l hnh chiu trcd o? HS: Tr li GV: Hnh chiu trc o c v trn 1 mt phng hay 3 mt phng HS: Tr li T gv chuyn sang mc tip theo GV: Hnh chiu trc o c xy dng nh th no ? GV: Treo tranh hnh hnh 5.1 ln bng: Ch co hc sinh cch xy dng hnh chiu trc o GV: V sao phng chiu l ta v khng song song vi mt phng P hoc khng c song song vi cc trc to HS: Tr li Hot ng 2: Tm hiu thng s c bn ca hnh chiu trc o GV: Th no gi l trc o HS: Tr li GV: Vy gc to bi cc trc o gi l gc trc o11

GV:NGUYN THANH TIb. H s bin dng - Khi nim h s bin dng

NM HC:2011-2012GV: a ra v d ssau gi HS tr li th no l h s bin dng GV: ua ra kt lun Gc gia cc trc o v h s bin dng l 2 thng s c bn ca hnh chiu trc o Hot ng 3: Tm hiu hnh chiu trc o vung gc u GV: V tr tng i gia mt phng P v phng chiu l HS: Tr li

II. HNH CHIU TRC O VUNG GC U - Hnh chiu trc o - Cc h s bin dng vung gc u c: l vung gc vi mt phng P - p=q=r 1. Thng s c bn - Cc gc to bi gc trc o: xo'y' = y''z' = z''x' = 1200 - p=q=r =1 2. Hnh chiu trc o ca hnh trn III. HNH CHIU TRC O XIN GC CN - Khi nim hnh chiu trc o xin gc cn 1. Gc gia cc trc o 2. H s bin dng IV. CCH V HNH CHIU TRC O

Hot ng 4: Tm hiu trc o xin gc cn GV: Khi l khng vung gc vi mt phng P; v 2 trong 3 h s bin dng bng nhau tng i mt gi l hnh chiu trc o xin gc cn.

Hot ng 5: GV: S dng bng 5.1 SGK hng dn tng bc cho hc sinh

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GV:NGUYN THANH TINgy son:30-08 PPCT : 06, 07

NM HC:2011-2012

Bai 6: THC HANH BIEU DIEN VAT THEI.Mc Tiu: _c c bn v hnh chiu vung gc ca vt th n gin _ v c hnh chiu th 3, hnh ct v hnh chiu trc o ca vt th n gin t bn v hai hnh chiu II. Chun b : _dng c v :b dng c k thut v( thc ,compa,ke..), bt ch cng ,bt ch mm,ty _vt liu : giy A4 , giy k hoc k li _ti liu sgk _ bi:bn v hai hnh chiu ca vt th III.Ni Dung: Cho bn v hai hnh chiu ca vt th n gin, yu cu: _c bn v v hnh dung c hnh dng ca vt th _v hnh chiu th 3, hnh ct trn hnh chiu ng v hnh chiu trc o ca vt th _ghi cc kch thc ca vt th ln cc hnh chiu vung gc IV. Tin Trnh:cho bn v hnh 6.1 sgk(trang32) Hot ng 1: c bn v hai hnh chiu B sung hot ng gio vin gii thiu bn v 6.1,yu cu hc sinh c bn v(phn tch hnh chiu gip hc sinh hnh dung c hnh dng vt th) hot ng hc sinh Quan st bn v v c bn v t hnh dung ra hnh dng ca vt th

hot ng 2: v hnh chiu th 3,h nh c t v h nh chi u tr c o c a v t th B sung 1. hot ng gio vin 2. v hnh chiu th 3: sau khi m t hnh dng ca vt th (hnh 6.3 sgk)hng dn hc sinh v hnh chiu cnh t hai hnh chiu cho.ln lt v tng b phn nh cch v gi ch L bi 3(hnh 6.4 sgk) 3. v hnh ct :yu cu hs : _nu nhn xt hnh chiu ng ca vt th (i xng ) _xc nh mt phng ct _nu cch trnh by bn v hnh ct ca vt th c hnh chiu ng l hnh i xng 3.v hnh chiu trc o: hng dn cc bc tin hnh v hnh chiu trc o ca vt th nh sgk * hng dn hs cch trnh by bn v tng t nh bi 3 13 hot ng hc sinh nh li kin thc c hc bi 3 kt hp vi s hng dn ca gv v c hnh chiu th 3 ca vt th theo yu cu ca gv

+hn xt hnh chiu ng ca vt th +xc nh mt phng ct +trnh by hnhv(hnh 6.5)

c sgk v v hnh chiu trc o

GV:NGUYN THANH TI

NM HC:2011-2012

hot ng 3:bi tp B sung hot ng gio vin Chia 6 b i trong h nh 6.7 cho 6 nh m hs.yu cu:v hnh chiu th 3,hnh c t v hnh chi u trc o c a v t th hot ng hc sinh l m theo y u c u c a gv

V: RT KINH NGHIM-B SUNG

14


NM HC:2011-2012

Bi 7: HNH CHIU PHI CNHI/ MC TIU 1. Kin thc: GV cn lm cho HS: - Hiu ni dung c bn ca mt s tiu chun v trnh by bn v k thut - C thc thc hin cc tiu chun ca bn v k thut 2. K nng: - Vn dng nhanh, ng, r rng 5 tiu chun trnh by bn v k thut. - Cho HS cc v d c th p dng trong cc tnh hung xy ra. 3. Thi : - Cn hng dn cho HS ngn gn, r rng, theo tng phn, t cc cu hi m lin quan n yu cu thc t. II/ CHUN B - Nghin cu k bi dy, tranh v phng to, t giy A4, III/ TIN TRNH BI DY - n nh lp: s s ?, lm quen lp - Bi mi: * Hot ng 1: Tm hiu ngha ca tiu chun v bn v k thut (3) - HS bit vai tr ca bn v k thut i vi i sng v sn xut ( GV nhc li hoc hi HS) - V sao ni bn v k thut l ngn ng chung trong k thut ? * Hot ng 2: B sung Gii thiu kh giy (7) Ni dung I- KH GIY - Cc kh giy chnh: A0 , A1 , A2 , A3 , A4

Hot ng ca GV v HS - V: bn v k thut c xy dng da trn nhng quy tc hay tiu chun chung no? - V sao bn v phi v theo cc kh giy nht nh? HS: lin quan n thit b sn xut giy v in n - C my loi kh giy chnh ? GV hng dn cho HS hiu vic chia cc kh giy, n c lgic. Da vo bng 1.1 v hnh 1.1 ( t kh giy A0 chia cc kh giy A1, A2, A3, A4 nh th no) - Cch chia khung bn v v khung tn ( hnh 1.2) - Cho HS v nh chia theo hnh 1.2 vo t giy A4 ( hm sau kim tra)

15

GV:NGUYN THANH TI* Hot ng 3: B sung Gii thiu t l v nt v (15) Hot ng ca GV v HS - HS c khi nim v t l khi hc Ton v bn a L. - Th no l t l ca bn v ? - C my loi t l ? l g ? HS: t l thu nh, phng to, nguyn hnh. - Hng dn HS c TCVN SGK

NM HC:2011-2012

Ni dung II- T L

T l l t s gia kch thc o c trn hnh biu din ca vt th v kch thc thc tng ng trn vt th .

- Cc loi nt v ( nt lin m, lin mnh, t mnh, nt III- NT V gch chm mnh) biu din cc ng g ca vt th ? 1. Cc loi nt v Cho HS gii thch bng v d hnh 1.3 Xem bng 1.2 SGK -Vic quy nh chiu rng ca nt v c lin quan g n bt v ? V d hnh 1.3 2.Chiu rng ca nt v

Hot ng 4:

Gii thiu ch vit v cch ghi kch thc (17)

16

GV:NGUYN THANH TIB sung Hot ng ca GV v HS - Yu cu ca ch vit trn bn v k thut nh th no? - Kh ch c xc nh nh th no ? HS: chiu cao h ca ch hoa tnh bng mm Kiu ch hoa v thng quy nh vit nh th no? V n khc ch ghi thng ? VD: - c bit quy nh ghi du v ch s ? VD: S 1 ghi trong k thut khng c gch chn. S 2 khng ghi c vng trn chn. -

NM HC:2011-2012Ni dung IV- CH VIT Ch vit trn bn v k thut phi r rng, thng nht, d c. 1. Kh ch 2. Kiu ch xem hnh 1.4 V- GHI KCH THC 1. ng kch thc V bng nt lin mnh, u mt c v mi tn v t song song vi phn c ghi kch thc. 2. ng ging kch thc V bng nt lin mnh, k vung gc vi ng kch thc 3. Ch s kch thc Ch s kch thc ch tr s kch thc tht ca vt, khng ph thuc vo t l bn v v c ghi trn ng kch thc. VD: hnh 1.6 ; 1.7 4.K hiu ,R

Hng dn HS v ng ging v ng ghi kch thc. Sau cch vit ch s kch thc cho hp l. VD: hnh 1.5 SGK Nu n v di l mm th trn bn v ghi kch thc khng ghi n v pha sau. - Nu n v di khc mm th sao? HS: i ra mm ri ghi hoc ghi r n v sau - ch : ng ging kch thc khng c ct ng ghi kch kch thc. V d SGK c. HS tr li cu hi hnh 1.8

* -

Hot ng 5:

Tng kt, nh gi gi hc ( 3)

Cng c li bi hc : + Bn v k thut gm nhng tiu chun no ? + V sao bn v k thut phi c lp theo cc tiu chun ? - Yu cu HS tr li cu hi v lm bi tp SGK, c phn thng tin b xung. - Nhn xt thc, tinh thn thi hc tp. - c trc bi hc sau ( bi 2) IV: RT KINH NGHIM-B SUNG 17

GV:NGUYN THANH TI

NM HC:2011-2012

Ngy son:23-08 PPCT : 08

KIM TRA MT TIT

Tit PPCT: 9

I/ MC TIU 1. Kin thc: GV cn lm cho HS: - Bit ni dung c bn ca mt s tiu chun v trnh by bn v k thut - C thc thc hin cc tiu chun ca bn v k thut _ V c HCPC 2. K nng: - Vn dng nhanh, ng, r rng 5 tiu chun trnh by bn v k thut. - Nm chc cch v HCPC 3. Thi : - Cn hng dn cho HS ngn gn, r rng, theo tng phn, t cc cu hi m lin quan n yu cu thc t. II/ CHUN B - T giy A4, bt ch ,thc III/ TIN TRNH BI DY bi: V HCPC ca mt cn nh c hnh chiu vung gc nh hnh v p n:

18

GV:NGUYN THANH TI

NM HC:2011-2012

Ngy son:23-08 PPCT :10

Bi 8: THIT K V BN V K THUTI/ MC TIU: 1. Kin thc: - Bit c cc giai on chnh ca cng vic thit k. - Hiu c vai tr ca bn v k thut. 2. K nng: - Hc sinh rn luyn c tnh t m, cn thn. - C th thit k c mt bn v k thut. II/ CHUN B BI GING: 1. Chun b ni dung: - Nghin cu sch gio khoa, nghin cu bi 8. - c sch tham kho lin quan n bi ging. 2. Chun b phng tin dy hc: 19

GV:NGUYN THANH TItng - M hnh hp ng dng hc tp. III/ TIN TRNH T CHC DY HC: 1. Cu trc v phn b bi ging: - Bi ging gm hai ni dung chnh: + Thit k. + Bn v k thut.

NM HC:2011-2012

- Tranh nh v sn phm c kh v cng trnh xy dng nh: t, my bay, cu, ng, nh cao

Trng tm l mi quan h gia cng vic thit k v bn v k thut. 2. Cc hot ng dy hc: Hot ng 1: Tm hiu v thit k B sung

Hot ng ca gio vin sn phm c kh v cng trnh xy dng.

Hot ng ca hc sinh

- GV cho hc sinh quan st mt s tranh nh v - HS quan st hnh nh. - GV: ch to cc sn phm v xy dng cc - HS: Ch , tp trung nghe. cng trnh ngi ta phi tin hnh thit k. - GV: Trnh by ni dung cc giai on thit k. 1. Cc giai on thit k: a) iu tra, nghin cu yu cu ca th trng v nguyn vng ca ngi tiu dng, hnh thnh tng v xc nh ti thit k. b) Cn c vo mc ch v yu cu ca ti thit k, thu thp thng tin, ra phng n thit k v tin hnh tnh ton lp bn v nhm xc nh hnh dng, kch thc, kt cu, chc nng ca sn phm. c) Lm m hnh, tin hnh th nghim hoc ch to th. d) Thm nh, phn tch, nh gi phng n thit k. Nu cn sa i, ci tin c20

- HS: Lng nghe.

- HS: Ghi chp vo v.

GV:NGUYN THANH TIphng n thit k tt nht. e) Cn c vo phng n thit k tt nht, tin hnh lp h s k thut. H s gm c cc bn v tng th v chi tit ca sn phm, cc bn thuyt minh tnh ton, cc ch dn v vn hnh s dng sn phm. GV: V s tm tt qu trnh thit k + S qu trnh thit k

NM HC:2011-2012

- HS: Xem s tm tt v ghi vo v.

Hnh thnh tng xc nh ti thit k

Thu thp thng tinTin hnh thit k

Lm m hnh th nghim, ch to th

Khng t

Thm nh, nh gi phng n thit k 21 Lp h s k thut

GV:NGUYN THANH TI

NM HC:2011-2012- HS: c SGK, tho lun cc bc tin hnh thit k hp ng dng hc tp.

GV: Ly v d v thit k hp ng dng hc tp. - Thng qua v d: on thit k. - HS: Quan st cc hnh v trong SGK hiu r ni dung - HS: Tr li cu hi v a ra

GV: Dn dt HS hiu r ni dung ca tng giai cc giai on thit k. - GV: Cho hc sinh quan st cc hnh trong SGK. kin xut. GV: Nu cu hi: Hy nhn xt qu trnh thit k hp ng dng hc tp v xut kin ci tin.Hot ng 2: B sung

Hot ng ca gio vin GV: Th no l bn v k thut? GV: Bn v k thut l cc thng tin k thut c trnh by di dng ho theo cc quy tc thng nht. GV: C nhng loi bn v no? GV: C hai loi bn v k thut. - Bn v c kh gm c bn v lin quan n thit k, ch to, lp rp, kim tra, s dng cc my mc v thit b. - Bn v xy dng gm cc bn v lin quan n thit k, thi cng, lp rp cc cng trnh kin trc v xy dng. GV: Vai tr ca bn v k thut i vi thit k? trng i vi thit k v ch to sn phm.22

Hot ng ca hc sinh HS: Tr li

HS: Tr li

HS: c SGK tho lun vai tr

- Bn v k thut c vai tr ht sc quan ca bn v k thut.

GV:NGUYN THANH TIGV: Nhn mnh bn v k thut l Ngn ng ca k thut: - c cc bn v thu thp thng tin lin quan n ti thit k. - V cc bn v phc ca sn phm khi lp phng n thit ek th hin tng thit k. - Trong giai on tnh ton thit k phi lp cc bn v xc nh hnh dng v kch thc ca sn phm. - Trong giai on thm nh, nh gi phi thng qua cc bn v k thut trao i kin, sa i phng n thit k. - Trong giai on lp h s thit k phi lp cc bn v tng th v chi tit ca sn phm.Hot ng 3: Tng kt, nh gi B sung

NM HC:2011-2012

Hot ng ca gio vin GV: t cu hi tng kt, nh gi xem hc sinh tip thu n u. GV: Trong thit k gm c nhng giai no? GV: Vai tr ca cc giai on l nh th no? GV: Th no l bn v k thut? GV: Vai tr ca bn v?

Hot ng ca hc sinh

HS: Tr li HS: Tr li HS: Tr li HS: Tr li

IV. Cng c bi hc

23

GV:NGUYN THANH TI

NM HC:2011-2012


Bai 9: BAN VE C KH

Tiet PPCT: 11

I.Mc tiu : 1. Kin thc : giup hoc sinh biet cach oc c ban ve ky thuat. 2. K nng : rn luyn cho HS k nng quan st, c bn v mt bng tng th n gin v bn v c kh n gin. 3. Thi : qua bi ny gip HS thch th khi c bn v ng thi gio dc cho HS tnh nghim tc, t gic. II. Chun b : 1 Gao vin : nghin cu ni dung bi 9 SGK, SGV. Chun b cc tranh v phng to 2. Hc Sinh : c bi trc khi n lp . n tp kin thc bi 8: III. Tin trnh bi dy : 1. n nh lp, kim tra s s ( 1 ) 2. Kim tra bi c ( 5) a. Bn v mt bng tng th l g ? nu cc loi hnh cn thit k s b 1 ngi nh . b. B. Nu cc c im c bn ca tng loi hnh biu din dng cho v nh . 3. Dy bi mi : Thi gian Ni dung chnh Hot ng ca GV v HS

10

Bi 12 . Thc hnh Bn v xy dng 1.c bn v mt bng tng th - Trm x c 4 ngi nh: 1. Nh khm bnh . 2. Nh iu tr . 3. Nh KHHG . 4. Nh v sinh .

Hot ng 1 : c bn v mt bng tng th . -GV s dng phng php trc quan cho HS quan st tranh v hnh 12.1 SGK HS c c bn v GV yu cu HS tr li cc cu hi SGK : + Trm x c bao nhiu ngi nh ? 24

GV:NGUYN THANH TI- nh s nh trn hnh chiu phi cnh - Xc nh hng quan st.

NM HC:2011-2012-HS da vo nhng kin thc hc v ghi ch tr li . - HS hnh dung c quan cnh trm x GV s dng tranh v hnh 12.2 SGK . V yu cu HS nh s cc ngi nh trn hnh chiu phi cnh theo ghi ch trn mt bng tng th. Tronh hot ng ny GV c th s dng cu hi : + Da vo u xc nh v tr cc ngi nh ?( da vo li i v hnh dng ngi nh ) - GV Cho HS quan st tranh v hnh 12.3 SGK v yu cu HS st nh hng quan st nhn c mt ng ngi nh . Hot ng 2 : c bn v mt bng 1 ngi nh n gin. - GV S dng phng php tyrc quan v tho lun theo nhm . Cho HS quan st tranh v hnh 12.4, phn chia lp thnh tng nhm ( 3 nhm ). -GV yu cu HS thc hin cc vic sau : + Tnh ton, ghi cc kch thc thiu trn bn v . + Tnh dn tch phng ng, phng sinh hotchung. - GV phn mi nhm tnh din tch 1 phng sau c i dn nhm bo co kt qu . + Nhm 1 : phng ng 1 . + Nhm 2 : phng ng 2. + Nhm 3 : phng sinh hot chung . -Trong hot ng ny GV c th s dng cc cu hi sau gi cho HS lm bi : + Cc phng c hnh dng g ? ( hnh ch nht ) + Tnh din tch hnh CN?( di x rng ) . + Mun tnh din tch s dng ca phng ta st nh chiu di, rng nh th no ?( ly khong cch gia trc tng tr i dy tng). - Sau khi cc nhm bo co GV nhn xt kt qu tng nhm.

25

2. c bn v mt bng - Tnh ton cc kch thc cn thiu trn bn v. - Tnh din tch cc phng ng, phng sinh hot chung (m2) + Phng ng 1 : ( 4,2- 0,22/2 0,11/2 ) x ( 4 2 x 0,22/2 ) = 15,25m 2 Phng ng 2 : ( 4- 0,22/2 0,11/2 ) x ( 4 2 x 0,22/2 ) = 14,5 m2 Phng sinh hot chung . ( 5,2 2 x 0,22/2 ) x (3,8 2 x 0,22/2 )= 17,83 m2

4. Cng c ( 3 ) - Hot ng 3 : Tng kt nh gi : +GV nhn xt nh gi gi thc hnh : . S chun b ca HS thc hin bi tp v thi ca HS. 25

GV:NGUYN THANH TI5. GV giao nhim v cho HS ( 1) - HS c trc bi 10 SGK .

NM HC:2011-2012


Bi 10: THC HNH LP BN V CHI TIT CA SN PHM C KH N GIN

Tit PPCT: 12, 13

I.MC TIU - Lp c bn v chi tit t vt mu hoc t mt bn v lp ca mt sn phm n gin - Hnh thnh c k nng lp bn v k thut v tc phong lm vic theo quy trnh II. CHUN B - Dng c v nh thc, eke, compa,bt ch, ty, Giy, Sch gio khoa, Vt mu - Mt s hnh nh ca mt s vt mu nh hp ng dng hc tp III. NI DUNG - Lp bn v chi tit ca sn phm c kh n gin t vt mu hoc t bn v IV. TIN HNH Hot ng 1: Chun b Hot ng ca hc sinh c sch gio khoa, nm vng cch lp mt bn v chi tit c bn v lp, phn tch cc chi tit cn v hiu r hnh dng, kch thcv cng dng ca chi tit Hot ng 2: Lp bn v chi tit Hot ng ca hc sinh Sau khi c v phn tch kt cu v hnh dng chi tit, chn phng n biu din, chn t l thch hp v tin hnh v theo trnh t Cc kch thc o trc tip trn vt mu hay ly t cc bn v ( Nn lm trn s) Chn c hnh dng,hnh ct, mt ct thch hp. Din t c hnh dng v cu to ca vt hay chi tit Hot ng 3: nh gi kt qu 26 Hng dn ca gio vin Gio vin ch r cc chi tit cn v bng nt lin, nt t, v phn tch kt cu ca tng hnh dng ca chi tit Giao cho mi nhm v mt dng chi tit , mt mt ct hoc mt hnh chiu ca mu Hng dn ca gio vin Nn hng dn chi tit tng phn, nu tng cch v , cch biu din mt bn v Gip hc sinh nm c v hiu c th no l mt bn v lp , chi tit bn v cn th hin r rng chnh xc

-

-

GV:NGUYN THANH TI-

NM HC:2011-2012

Hc sinh t nh gi bn v ca mnh Gio vin nhn xt v cho im tng bn v, rt kinh nghim Ch ra nhng im cn sa v ch sai t v tt hn cho cc bI sau Hot ng 4: Cng c v giao nhim v V nh c trc bi hc 11 Su tp mt s tranh lin quan ti bi hc

Cu hi trc nghim Cu1: Bn v lp l bn v dng a. Tho cc chi tit b. Trnh by hnh dng v v tr tng ca mt sn phm c. Da vo v tr tng quan ca mt nhm chi tit lp rp d. Kim tra v hon thin mt bn v Cu 2: C bao nhiu bc lp mt bn v chi tit a. 2 bc b. 3 bc c. 4 bc d. 5 bc Cu3: Phn ghi ch ca mt bn v dng a. Kim tra bn v b. Ghi cc yu cu k thut v ni dung khung tn c. Cho ta bit cch b tr mt chi tit d. Cho ta bit ng no v m, v m

27


NM HC:2011-2012 Tit PPCT: 14

Bi 11: BN V XY DNG

I. Mc tiu: Qua bi hc hc sinh cn nm c: 1. Kin thc: - Kha qut v cc loi bn v xy dng v cc loi hnh biu din trong bn v nh II. Chun b ca thy v tr: - Gio vin: sgk, gio n, phng tin dy hc cn thit. - Hc sinh: cc kin thc c c, sgk, v ghi, dng c hc tp cn thit III. Phng php dy hc: - C bn dng phng php gi m vn p, pht hin v gii quyt vn , thng qua cc hot ng iu khin t duy hc sinh nm bt kin thc. IV. Tin trnh dy hc: 1. On nh lp: - Kim tra s s ca lp. 1. Ni dung bi mi: Hot ng 1: t vn : HGV - cho hc sinh xem bn v phi cnh kin trc ( hoc nh chp mt cng trnh hon chnh v t vn : + c c cng trnh ny cn nhiu bn v khc nhau trong qu trnh thit k v thi cng. - ln lt gii thiu tng bn v trong qu trnh thit k v thi cng. - kt lun: cc cng trnh xy dng d ln hay nh trc khi xy dng thng c h thng bng cc bn v Hot ng 2: tm hiu v bn v mt bng tng th HGV - yu cu hc sinh quan st hnh 11.1a v cho bit: nhn t u m c c hnh nh nh bn v mt bng tng th? Trn bn v mt bng tng th, biu din nhng g? - tng hp li cc cu tr li ca hc sinh - s dng hnh 11.1b c phng to, ly mt s ming giy nh ( c in s th hin phn cng trnh) yu cu hc sinh quan st v dn vo v tr tng ng. Hot ng 3: tm hiu v bn v cc hnh biu din ngi nh HGV HHS + cha cp ti cc khi nim: mt bng, mt ng, mt + quan st hnh v, tm hiu hng chiu, v ct, yu cu hc sinh quan st cc hnh trong hnh 11.2 v tr mt phng ct cho bit: l hnh chiu hay hnh ct. Hng chiu (hay v tr mt phng ct) u. Gio vin c th gi nu hc sinh gp kh khn Tr li cu hi theo s iu khin ca gio 28 HHS - quan st v suy ngh HHS - quan st, nhn bit

- quan st, nhn bit - ghi chp v hiu c ngha ca bn v xy dng

- tr li, ghi li nhng thng tin kt lun - xc nh v tr tng ng ca phn cng trnh trn hnh chiu phi cnh

GV:NGUYN THANH TI

NM HC:2011-2012

+ tng hp li cc cu tr li ca hc sinh v kt lun: vin - hnh biu din nh hnh a c gi l mt ng + ghi chp, tm tt - hnh biu din nh hnh b c gi l mt ct - hnh biu din nh hnh c, d c gi l mt bng + yu cu hc sinh tham kho ni dung sgk trang 59 v pht + c sch v pht biu khi nim v cc mt biu li cc nh ngha v: mt bng, mt ng v mt ct Hot ng 4: cng c, giao nhim v cho hc sinh HGV Mt s cu hi gi : + so snh s khc nhau gia mt bng tng th so vi hnh chiu bng khi biu din mt vt th n gin? + so snh s khc nhau ca cc k hiu cu thang trn mt bng tng 1 v tng 2? HHS

+trn mt bng tng th khng biu din chi tit, dng nhiu k hiu biu din cng trnh, cy ci ng s + k hiu cu thang mt bng tng 1 ch c mt cnh thang th nht b ct la; mt bng tng 2 c + so snh s khc nhau gia mt ng ngi nh vi c hai cnh thang cc hnh chiu ng v hnh chiu cnh ca mt vt + mt ng ca ngi nh v bng nt mnh, khng th? biu din phn khut, c th v thm cy ci + so snh mt bng v mt ct ngi nh vi cc hnh ct ca mt vt th + trn mt bng v mt ct ngi nh khng biu din + giao bi tp v yu cu hc sinh c trc bi 12 phn khut nh + ghi bi tp v nh


29

GV:NGUYN THANH TI NM HC:2011-2012 Bi 12: THC HNH: C BN V XY DNG Tit PPCT: 15I.Mc tiu : 4. Kin thc : Gip hc sinh n tp, cng c nhng kin thc hc v bn v xy dng bi 11 SGK . 5. K nng : rn luyn cho HS k nng quan st, c bn v mt bng tng th n gin v bn v ngi nh n gin. 6. Thi : qua bi ny gip HS thch th khi c bn v ng thi gio dc cho HS tnh nghim tc, t gic. II. Chun b : 1 Gao vin : nghin cu ni dung bi 12 SGK, SGV. Chun b cc tranh v phng to cc hnh t 12.1 n 12.4 SGK 2. Hc Sinh : c bi 12 SGK trc khi n lp . n tp kin thc bi 11: III. Tin trnh bi dy : 6. n nh lp, kim tra s s ( 1 ) 7. Kim tra bi c ( 5) c. Bn v mt bng tng th l g ? nu cc loi hnh cn thit k s b 1 ngi nh . d. B. Nu cc c im c bn ca tng loi hnh biu din dng cho v nh . 8. Dy bi mi : Thi gian Ni dung chnh Hot ng ca GV v HS

10

Bi 12 . Thc hnh Bn v xy dng 1.c bn v mt bng tng th - Trm x c 4 ngi nh: 1. Nh khm bnh . 2. Nh iu tr . 3. Nh KHHG . 4. Nh v sinh . - nh s nh trn hnh chiu phi cnh - Xc nh hng quan st.

Hot ng 1 : c bn v mt bng tng th . -GV s dng phng php trc quan cho HS quan st tranh v hnh 12.1 SGK HS c c bn v GV yu cu HS tr li cc cu hi SGK : + Trm x c bao nhiu ngi nh ? -HS da vo nhng kin thc hc v ghi ch tr li . - HS hnh dung c quan cnh trm x GV s dng tranh v hnh 12.2 SGK . V yu cu HS nh s cc ngi nh trn hnh chiu phi cnh theo ghi ch trn mt bng tng th. Tronh hot ng ny GV c th s dng cu hi : + Da vo u xc nh v tr cc ngi nh ? ( da vo li i v hnh dng ngi nh ) - GV Cho HS quan st tranh v hnh 12.3 SGK v yu cu HS st nh hng quan st nhn c mt ng ngi nh . Hot ng 2 : c bn v mt bng 1 ngi nh n gin. - GV S dng phng php tyrc quan v tho lun theo nhm . Cho HS quan st tranh v hnh 12.4, phn chia lp

25

2. c bn v mt bng - Tnh ton cc kch thc cn thiu trn bn v. - Tnh din tch cc phng ng, phng sinh hot chung (m2)

30

GV:NGUYN THANH TI+ Phng ng 1 : ( 4,2- 0,22/2 0,11/2 ) x ( 4 2 x 0,22/2 ) = 15,25m 2 Phng ng 2 : ( 4- 0,22/2 0,11/2 ) x ( 4 2 x 0,22/2 ) = 14,5 m2 Phng sinh hot chung . ( 5,2 2 x 0,22/2 ) x (3,8 2 x 0,22/2 )= 17,83 m2

NM HC:2011-2012thnh tng nhm ( 3 nhm ). -GV yu cu HS thc hin cc vic sau : + Tnh ton, ghi cc kch thc thiu trn bn v . + Tnh dn tch phng ng, phng sinh hotchung. - GV phn mi nhm tnh din tch 1 phng sau c i dn nhm bo co kt qu . + Nhm 1 : phng ng 1 . + Nhm 2 : phng ng 2. + Nhm 3 : phng sinh hot chung . -Trong hot ng ny GV c th s dng cc cu hi sau gi cho HS lm bi : + Cc phng c hnh dng g ? ( hnh ch nht ) + Tnh din tch hnh CN?( di x rng ) . + Mun tnh din tch s dng ca phng ta st nh chiu di, rng nh th no ?( ly khong cch gia trc tng tr i dy tng). - Sau khi cc nhm bo co GV nhn xt kt qu tng nhm.

9. Cng c ( 3 ) - Hot ng 3 : Tng kt nh gi : +GV nhn xt nh gi gi thc hnh : . S chun b ca HS thc hin bi tp v thi ca HS. 10. GV giao nhim v cho HS ( 1) - HS c trc bi 13 SGK . * Cu hi trc nghim. Cu 1. K hiu sau y quy c loi ca g ?

a. Ca cun . b. Ca i n 2 cnh . c. Ca kp 2 cnh . d. Ca la n 2 cnh . Cu 2 : Cho HS quan st mt hnh chiu phi cnh , mt hnh v mt bng v mt hnh v mt ng ca khu tp th. - c c mt ng nh hnh v th phi quan st theo hng no ? a. Hng Bc . b. Hng Ty. c. Hng ng . 31

GV:NGUYN THANH TId. Hng Nam.

NM HC:2011-2012

32

GV:NGUYN THANH TI

NM HC:2011-2012


Bi 13: LP BN V K THUT BNG MY TNH IN T

Tit PPCT: 16

I, MC TIU BI DY - Hc sinh bit c khi nim c bn v mt h thng v bng my tnh. - hc sinh bit khi qut v phn mm AutoCAD. II, CHUN B BI GING 1, Chun b ni dung - Nghin cu k bi 13 SGK - Nghin cu s dng phn mm AutoCAD v c bn v ba chiu n gin v xy dng c vt th ba chiu n gin. - Tham kho thm ti liu lin quan. 2, Chun b dng dy hc - Hnh v 13.1 n 13.5 SGK - Mtvi bn v k thut bng my tnh v d minh ho. III, TIN TRNH BI DY 1, On nh lp, kim tra s s [1`] 2, Kim tra bi c [4`] 3, Nghin cu kin thc mi [35`]T/L NI DUNG BI HC PHNG PHP DY - HC

I, KHI NIM CHUNG Ngy nay, trong thi i cng ngh thng tin, cc bn v k thut c lp vi s tr gip ca my tnh. Vi cc u im: -Bn v c lp mt cch chnh xc v nhanh chng: -D dng sa cha, b sung, thay i, lu tr . -Gii phng con ngi ra khi cng vic nng nhc v trnh n iu.

Hot ng 1: Gii thiu chung Trc y ngi ta s dng cc dng c v nh bt ch, thc, compa, ke lp bn v k thut. Ngy nay, trong thi i cng ngh thng tin, cc bn v k thut c lp vi s tr gip ca my tnh vi cc u im l bn v c lp mt cch chnh xc v nhanh chng; d dng sa cha, b sung, thay i, lu tr; gip cho con ngi lm vic mt cch nh nhn v khng n iu trong khi lp bn v.

II, KHI QUT V H THNG V Hot ng 2: Tm hiu khi qut v h thng v k thut bng K THUT BNG MY TNH my tnh (h thng CAD) Cc h thng CAD xut hin vo khong gia nm 1960 v c p dng ngy cng rng ri trong cc lnh vc thit k GV:Em hy k mt vi lnh vc thit k m cn n bn v k thut? HS: tr li: GV: kt lun H thng CAD gm c hai phn: phn cng, phn mm. 33

GV:NGUYN THANH TI

NM HC:2011-2012

1, Phn cng L t hp cc phng tin k GV: s dng hnh 13.1 gii thiu cho HS thut gm my tnh v cc thit b GV: cc thit b no dng a thng tin vo v xut a thng tin vo v ra. thng tin ra? * HS nhn tranh v tr li * GV gii thch r cng dng ca tng thit b 2, Phn mm Phn mm ca h thng CAD m bo thc hin cc hot ng thnh lp bn v k thut nh: -To ra cc i tng v: ng thng, ng trn, ng cong, mt cong, vt th ba chiu, ; -Gii cc bi ton dng hnh v v hnh; -Xy dng cc hnh chiu vung gc, hnh ct, mt ct; -Xy dng cc loi honh chiu truch o, hnh chiu phi cnh; -T, v k hiu mt ct vt liu; *GV: dng hnh 13.2 SGK gii thiu cho HS: to ra cc i -Ghi kch thc; tng v th ta phi ra lnh cho my tnh thc hin (nu c my tnh th thc hin v mt vi hnh hc n gin cho HS xem). * Cc thit b phn cng, cc chng trnh phn mm d c hin i n v hon thin n au cng khng th thay oc ht mi hot ng tr tu ca con ngi. iu quyt nh trong v k thit k vn l kin thc v nng lc ca ngi s dng. * Hot ng 3: Tm hiu khi qut v phn mm AutoCAD. * GV gii thiu chung v phn mm (ging trong SGK). c III, KHI QUT V PHN MM bit c cc kh nng c bn sau: AUTOCAD - Lp bn v hai chiu trn mt phng ging nh v truyn 1, Bn v hai chiu thng bng dng c v.(GV s dng hnh 13.3 SGK gii thiu Phn mm AutoCAD p ng cho HS xem hoc nu c my tnh biu din cho HS xem) oc mi yu cu ca hot ng v truyn thng trn mt phng * GV s dng hnh v 13.4 v 13.5 SGK minh ho (nu c hai chiu. my tinh th thc hin v mt vi hnh khi n gin) 2, M hnh vt th ba chiu xy dng m hnh vt th cn thit k xut pht t cc vt AutoCAD c kh nng to ra m th n gin nht gi l cc khi hnh hc c bn, khi hp, hnh vt th trong khng gian ba khi cu, khi nm, khi nn, khi tr v khi xuyn. Sau chiu ca cc i tng cn thit lin kt cc khi li vi nhau bng nhiu cch to nn vt th k, sau t ng xy dng bn cn thit k. v cc hnh chiu, hnh ct, mt Sau khi to xong vt th cn thit k, ta ra lnh cho ct,trn mt phng hai chiu t AutoCAD t ng xy dng cc loi hnh chiu vung gc m hnh vt th ba chiu. (nh trong bi thc hnh s 3 HS lm), (trc o, phi cnh) 34

GV:NGUYN THANH TI

NM HC:2011-2012trn mt phng, cc loi hnh ct, mt ct,(ging nh trong bi thc hnh s 6) theo yu cu ca ngi s dng v b tr cc hnh chiu ny ln mt bn v.

* Hot ng 4: Tng kt, nh gi +Ti sao cn phi lp bn v bng my tnh ? +Nu cc thnh phn ca mt h thng CAD v cc nhim v ca chng ? +Phn mm AutoCAD c th thc hin c cc cng vic g? Theo em cng vic g l mi v th v ? HS tr li, GV nhn xt, b sung, nh gi v cho im. Tng kt kin thc trng tm ca bi. Yu cu HS v nh hc bi c v tr li cc cu hi cui bi trong SGK, HS c trc bi 14.

35


NM HC:2011-2012

Bi 14: N TP PHN V K THUT

Tit PPCT: 17

I. Mc tiu: Qua bi hc hc sinh cn nm c: 1. Kin thc: - On tp li phn v k thut 2. T duy: - Bit quy l v quen. Xy dng t duy lgic, linh hot. 3. Thi : - Cn thn, chnh xc trong tnh ton, lp lun - Hng th trong hc tp, tch cc pht huy tnh c lp trong hc tp II. Chun b ca thy v tr: - Gio vin: sgk, gio n, phng tin dy hc cn thit. - Hc sinh: cc kin thc c c, sgk, v ghi, dng c hc tp cn thit III. Phng php dy hc: - C bn dng phng php gi m vn p, pht hin v gii quyt vn , thng qua cc hot ng iu khin t duy hc sinh nm bt kin thc. IV. Tin trnh dy hc: 1. On nh lp: - Kim tra s s ca lp. 2.Ni dung n tp Hot ng 1: h thng ho kin thc: HGV HHS + yu cu hc sinh theo di s h thng ho kin + hc sinh theo di v trnh by li thc phn v k thut trong sgk trang 71 Hot ng 2: cu hi n tp: HGV HHS 1. trnh by ngha ca cc tiu chun bn v k thut + hc sinh ghi chp v son cc cu hi 2. th no l phng php hnh chiu vung gc trn vo v 3. so snh s khc nhau gia phng php chiu gc th nht v gc th 2 4. th no l hnh ct v mt ct? Hnh ct v mt ct dng lm g? 5. th no l hnh chiu trc o? Hnh chiu trc o dng lm g? 6. hnh chiu trc o vung gc u v hnh chiu trc o xin gc cn c cc thng s nh th no? 7. th no l hnh chiu phi cnh? Hnh chiu phi cnh dng lm g? 8. bn v k thut c vai tr nh th no trong thit k? 9. bn v chi tit v bn v lp dng lm g? 10. cch lp bn v chi tit nh th no? 36

GV:NGUYN THANH TI11. trnh by cc c im ca cc loi hnh biu din ngi nh 12. trnh by khi qut h thng v k thut bng my tnh?

NM HC:2011-2012

KIM TRA HC K I

Tit PPCT: 18

37


NM HC:2011-2012

Chng III: VT LIU C KH V CNG NGH CH TO PHI Bi 15: VT LIU C KH

Tit PPCT: 19

I. Mc tiu: Qua bi hc hc sinh cn nm c: 1. Kin thc: - Tnh cht c bn ca vt liu nh bn, do, cng (nh ngha, cng thc tnh v ngha ca chng) v mt s loi vt liu thng c dng trong ngnh c kh - T tnh cht ca vt liu suy ra c ng dng ca chng trong sn xut c kh - C thc tm hiu cc loi vt liu k thut trong i sng 2. Thi : - Cn thn, chnh xc trong tnh ton, lp lun - Hng th trong hc tp, tch cc pht huy tnh c lp trong hc tp II. Chun b ca thy v tr: - Gio vin: sgk, gio n, phng tin dy hc cn thit. + tranh v hnh 15 sgk + mt s dng: chi tit my c ch to t cc loi vt liu khc nhau (kim loi, phi kim loi) chng hn: bt vit, kp giy, ng h eo tay III. Phng php dy hc: - C bn dng phng php gi m vn p, thuyt trnh, c minh ho v gii thch IV. Tin trnh dy hc: 1. On nh lp: - Kim tra s s ca lp. 2. Ni dung bi mi: Hot ng 1: n tp, kim tra cng c kin thc c phc v cho hc tp kin thc mi Hot ng ca gio vin v hc sinh Gm cc cng vic sau: 1. gii thiu bn ca vt liu: Yu cu hc sinh c ni dung tng ng trong sgk, tr li cc cu hi sau: bn ca vt liu l g? Ni dung I. mt s tnh cht c hc c trng ca vt liu: 1. bn: + bn c coi l kh nng chng li bin dng do hay ph hu ca vt liu di tc dng ca ngoi 2 lc. bn c k hiu bng ch ( N / mm ) + bn ko vi c trng bi gii hn bn ( b ): b = P* / Fo

( N / mm )2

Trong : P* l lc ko ln nht tc dng ln mu, Fo l tit din ngang ban u ca mu, ( Fo = d o 2 / 4 ) 2. do: c nh gi qua dn di tng i ca vt liu; 2. gii thiu do ca vt liu: c xc nh bng: Yu cu hc sinh c ni dung tng ng trong sgk, L LO = 1 .100% tr li cc cu hi sau: LO + do ca vt liu l g? + gii hnh bn ( do) ca vt liu ph thuc vo 3. cng (tnh cng): L kh nng chng li bin dng do ca lp b mt nhng yu t no? 38

GV:NGUYN THANH TI

NM HC:2011-2012

3. gii thiu cng ca vt liu: vt liu di tc dng ca ti trng thng qua dng Gii thch khi nim cng v nu s lc v cch c c coi nh khng bin i xc nh cng ca vt liu n v o cng + gii thiu mt s n v o cng: cng Brinell cng Rocwell cng Vicker Hot ng 2: gii thiu mt s loi vt liu thng dng Hot ng ca gio vin v hc sinh Ni dung Gv gii thiu s phn loi vt liu (nh nu II. Mt s loi vt liu thng dng mc II) (bng 15.1 sgk) 1. vt liu v c 2. vt liu hu c: a. nha nhit do b. nha nhit cng Yu cu hc sinh c ni dung bng 15.1 sgk v tr 3. vt liu compozit li cc cu hi sau: a. vt liu compozit nn v kim loi + nu thnh phn, tnh cht v ng dng ca vt liu b. vt liu compozit nn v vt liu hu c v c? + nha nhit cng v nha nhit do ging v khc nhau ch no (v thnh phn v tnh cht) + trong thc t, em bit nhng dng c, dng no c lm t vt liu v c/ vt liu nha nhit cng, nha nhit do?

Ngy son:23-08 39

GV:NGUYN THANH TIPPCT : 08

NM HC:2011-2012 Tit PPCT: 20 - 21

Bi 16: CNG NGH CH TO PHII.

Mc tiu: Sau khi hc xong bi ny hc sinh phi: - trnh by c bn cht, u nhc im v ng dng ca cng ngh ch to phi bng phng php c, gia cng p lc, hn trong sn xut c kh - T bn cht ca cng ngh suy ra c ng dng ca chng trong sn xut c kh - C thc tm hiu cc phng php ch to phi trong thc t II. Phng tin v phng php dy hc ch o: 1. phng tin dy hc: - tranh v (hnh 16.1 n 16.5 sgk) - mt s phi, chi tit my c ch to bng cc phng php c, rn, dp, hn; chng hn: knh eo mt, bm mng tay, ko, kp giy, ng h 2. Phng php dy hc ch o: Vn p, thuyt trnh c minh ho v gii thch. III. Cc hot ng dy hc 1. On nh lp: - Kim tra s s ca lp. 2. Ni dung bi mi: Hot ng 1: tm hiu cng ngh ch to phi bng phng php c: Hot ng ca gio vin v hc sinh Ni dung I. cng ngh ch to phi bng phng php c 1. bn cht, u nhc im ca cng ngh ch to phi bng phng php c - bn cht: c l phng php ch to sn phm kim loi bng cch rt kim loi lng vo khun c c hnh dng v kch thc xc nh: sau khi kim loi kt tinh, ng c v ngui, ngi ta tho g khun v thu c vt c c hnh dng, kch thc theo yu cu. Nh vy c l phng php gia cng khng phoi. Vt c dng ngay khng phi qua gia cng c c gi l chi tit c Vt c phi qua gia cng c t c chnh xc yu cu c gi l phi c - u nhc im: c th ch to c vt phm c hnh dng v kt cu phc tp, kch thc v khi lng ln; tn kim loi, sn phm d b khuyt tt 2. cng ngh ch to phi bng phng php c trong khun ct: (hnh 16.1 sgk)

- yu cu hc sinh c ni dung tng ng trong sgk v tr li cc vn sau: + bn cht ca c l g? + chi tit c v phi c khc nhau nh th no? - gio vin gii thch cc thut ng: khun c, gia cng khng phi + v sao c c th ch to c vt phm c hnh dng v kt cu phc tp, kch thc v khi lng ln? + v sao c li tn kim loi, sn phm d b khuyt tt?

Dng s khi gio vin m t, gii thch r rng cc bc v gii thch cc thut ng: mu, thao (li), xng thao, hm khun, u rt, u ngt, lng khun, vt liu nu Hot ng 2: tm hiu cng ngh ch to phi bng phng php gia cng p lc 40

GV:NGUYN THANH TIHot ng ca gio vin v hc sinh

NM HC:2011-2012Ni dung II. Cng ngh ch to phi bng phng php gia cng p lc: 1. cng ngh ch to phi bng phng php gia cng p lc: + rn, dp l cc dng c th ca nhm cc phng php gia cng kim loi bng p lc vi bn cht l dng ngoi lc tc dng thng qua cc dng c, thit b lm cho kim loi bin dng trng thi do theo hng inh trc nhm to ra vt phm cso hnh dng, kch thc theo yu cu Bng 16.2 sgk + u nhc im: cc phng php ny khng ch to c nhng sn phm c hnh dng v kt cu phc tp,sn phm qu ln hoc t nhng vt liu c do km (v d: gang, gm, s ) 2. ng dng: Rn, dp thng dng sn xut nhng dng nh dao, cuc, ko, ca, cc, inh

Yu cu hc sinh c ni dung sgk, tr li cc vn sau: + bn cht ca phng php ch to phi bng phng php gia cng p lc l g? + th no l kim loi bin dng trng thi do? + rn t do khc vi dp ch no? Ch gii thch: + ti sao go l rn t do? Dp th tch? + ti sao gia cng kim loi bng rn, dp thng khng lm thay i thnh phn v khi lng vt liu? + ti sao bng cch rn, dp kim loi li c kh nng lm tng c tnh vt liu? + ti sao bng cch rn, dp li d c kh ho v t ng ho? + ti sao cc phng php ny khng ch to c nhng sn phm c hnh dng v kt cu phc tp, sn phm qu ln hoc t nhng vt liu c do km? + em bit nhng loi dng c, dng no c ch to bng phng php rn dp?

Hot ng 3: gii thiu bn cht v ng dng ca cng ngh ch to phi bng phng php hn: Hot ng ca gio vin v hc sinh Yu cu hc sinh c ni dung sgk, tr li cc vn sau: + bn cht ca phng php hn kim loi l g? + hn h quang khc vi hn hi nhng im no? + v sao phng php ny c th to ra c nhng sn phm c kt cu phc tp hoc c to thnh t cc vt liu kim loi c tnh cht khc nhau? + v sao phng php ny lm bin dng vt hn? + trong thc t em bit nhng sn phm no c gia cng bng phng php hn? Ni dung III. Cng ngh ch to phi bng phng php hn: + bn cht: hn l phng php ni cc chi tit kim loi vi nhau bng cch nung nng ch ni n trng thi nng chy, sau khi kim loi kt tinh s to thnh mi hn + mt s phng php hn: Hn hi v hn h quang Bng 16.1 sgk + u nhc iu v ng dng ca phng php hn kim loi

Ngy son:23-08 PPCT : 08 41

GV:NGUYN THANH TI

Chng IV: CNG NGH CT GT KIM LOI V T NG HO TRONG CH TO C KHBi 17: CNG NGH CT GT KIM LOI I.- Mc tiu

NM HC:2011-2012 Tit PPCT: 22 - 23

Bit c : - Bn cht ca gia cng kim loi bng ct gt Nguyn l ct v dao ct Cc chuyn ng khi tin v cc kh nng gia cng ca tin

II.- Chun b bi ging1. Chun b ni dung a. Nghin cu bi 17 Sgk b. Su tm cc ti liu lin qua n gia cng kim loi bng ct gt 2. Chun b phng tin dy hc a. Tranh v phng to hnh 17.1 17.4 Sgk b. M hnh, vt liu hnh 17.2 (a,b) Sgk

III.- Kim tra bi c1. Cu 1: K tn mt s loi vt liu thng dng v nu cng dng ca chng. 2. Cu 2: Nu khi nim v phi, k tn cc phng php gia cng ch to phi hc.

IV.- Tin trnh ln lpThi lng Hot ng ca thy v tr Ni dung GV : - ch to cc chi tit my mc bng kim loi I.- Nguyn l ct v dao ct ngi ta thng lm ntn? 1. Bn cht ca gia cng vt HS: Ngi ta thng dng cc phng php nh rn, rp, liu bng ct gt: tin, phay, bo, .. Ly i mt phn kim loi tha GV: Trong cc phng php gia cng c cc phng ca phi (phoi) thu c chi php nh tin, phay, bo, .. ngi ta ct b i (ly bt tit c hnh dng v kch thc i) mt phn kim loi d tha ca phi c sn phm. theo yu cu (sn phm). Gi l gia cng ct gt. Vy bn cht ca gia cng ct gt l g? (v nhanh mt vi hnh minh ho) GV: Khi ta ct kim loi th phn kim loi tha b ly ra 2. Nguyn l ct: khi phi ta gi l phoi. Vy qu trnh hnh thnh phoi ntn? a. Qu trnh hnh thnh (a tranh phng to hnh 17.1) phoi: V d : phi c nh, dao ct chuyn ng tin vo -> lp B phn ct ca dao nh mt ci kim loi pha trc dao b tch ra khi phi -> b phn ct chm ct, di tc dng ca lc ca dao c tc dng ntn? (ngoi) ct lp kim loi pha HS: Tc dng nh mt ci chm ct, ct lp kl pha trc trc dao ra khi phi. dao. GV: ct c vt liu b. Chuyn ng ct: Phay, bo : Phi c nh, dao chuyn ng tnh tin ct c vt liu, gia dao v Tin : Phi chuyn ng quay, dao chuyn ng ngang phi phi c chuyn ng tng i hoc dc, cho vi nhau. Vy gia dao v phi phi ntn? Kt lun : - i tng : Phi (t b ct) v dao ct - thc hin ct : phi v dao ct phi c chuyn ng tng i i vi nhau v phi to thnh 42

GV:NGUYN THANH TIphoi GV: a ra tranh phng to hoc m hnh mo phng hnh 17.2 a. Sau va ch vo cc mt ca dao va t cc cu hi v vtr, cng dng ca chng.

NM HC:2011-20123. Dao ct (VD; dao tin ct t) a. Li ct chnh v cc mt ca dao ct : - Mt trc : - Mt sau : - Li ct chnh : - Mt y : b. Cc gc ca dao (Sgk) - Gc trc ( ) - Gc sau ( ): - Gc sc ( ) c. Vt liu lm dao - Thn dao : Thp tt - B phn ct : thp gi, hp kim cng

GV: a ra tranh phng to hoc m hnh m phng hnh 17.2b. Sau va ch vo cc gc ca dao va t cc cu hi v vtr, tc dng ca chng. GV: Khi dao ct vt liu th thn dao s chu tc dng lc ntn? Do vy n phi c lm bng loi vt liu g? HS: Thn dao phi chu tc dng lc rt ln, do vy n phi c lm bng loi thp tt GV: ct vt liu d dng th b phn ct phi c cc c im g? HS: Phi c cng cao, c kh nng chng mi mn, chu nhit cao. GV: a tranh phng to hnh 17.3 v gii thiu cc b phn chnh GV: M t s hot ng ca my tin (nu c phim Video v thc hin dy trn n chiu l tt nht) sau t cc cu hi : - C my loi chuyn ng chnh, v chuyn ng nh th no? HS: C 2 loi chuyn ng chnh : Chuyn ng ca phi v chuyn ng ca dao GV: Ring vi dao ct c my loi chuyn ng, tc dng ca tng loi chuyn ng? HS: C 3 loi chuyn ng : - chuyn ng ngang : - Chuyn ng dc : - Chuyn ng phi hp : GV: Nu mt s sn phm c gia cng trn my tin: HS : Trc my, trc ren, bu lng, cn xe p, vv..

II.- Gia cng trn my tin 1. My tin: 2. Chuyn ng khi tin: L chuyn ng ct bao gm: - Chuyn ng quay trn ca phi : to ra tc ct Vc (m/pht). - Chuyn ng tin dao: + Chuyn ng tin dao dc (Sd): ct t phi, gia cng mt u phi. + Chuyn ng tin dao ngang (Sng): gia cng theo chiu di chi tit (mt tr chi tit) + Chuyn ng tin dao phi hp: Gia cng cc mt cn, mt cu chi tit. 3. Kh nng gia cng ca my tin : - Mt tr trn xoay (ngoi v trong) - Mt cn (mt nn) ngoi v trong - Cc loi ren ngoi v ren trong. - Cc mt trn xoay nh hnh

V.- Cng c dn d: 1. Cng c bi 43


NM HC:2011-2012

Bi 18: Thc hnh: LP QUY TRNH CNG NGH CH TO MT CHI TIT C KH N GIN TRN MY TIN

Tit PPCT: 24

I/Mc tiu : Hc sinh bit cch lp c quy trnh cng ngh ch to mt chi tit my n gin trn my tin. II/ Chun b : 1. Chun b ni dung : - c SGK bi 18 - Nghin cu cc ti liu lin quan, chun b cc dng c vt liu cn thit nh : bt ch, thc k, giy .... 2. Chun b phng tin : - Chun b mt chi tit mu v bn v chi tit cn ch to - Tranh v phng to ca chi tit. III/ Tin trnh bi thc hnh : T chc lp : kim tra s s, n nh lp. Thi lng Ni dung bi hc Bi 18 : Lp trnh cng ngh ch to mt chi tit my n gin trn my tin * ch to mt chi tit my n gin trn my tin cn phi tin hnh theo trnh t sau : 1/ Tm hiu chi tit cn ch to (trn bn x chi tit) VD :1 x 450 1 x 450

Phng php dy hc Hot ng 1 : Hngdn hc sinh tm hiucu to ca chi tit. * GV s dng hnh v 18.1/SGK ch HS tm hiu cu to ca chi tit1 x 450 1 x 450

25

2040 25

25

2025 40

2/ Xy dng quy trnh cng ngh ch to chi tit - theo cc bc sau : * Bc 1 : Chn phi - Chn ng vt liu - ng knh phi ln hn ng knh ca chi tit * Bc 2 : lp phi ln mm cp ca my tin 44

* GV cho HS nt ra cc c im ca chi tit. * HS : - C dng hnh tr trn xoay vi hai ng bc c ng knnh v chiu di khc nhau. - Hai u c vt mp * GV a ra mu ca chi tit i chng vi bn v Hot ng 2 : Xy dng quy trnh cng ngh ch to chi tit. * GV : Quy trnh cng ngh l trnh t cc bc cn phi thc hin ch to 1 chi

GV:NGUYN THANH TI* Bc 3 : Lp dao ln i g dao ca my tin * Bc 4 : Tin mt cu

NM HC:2011-2012tit. * Gio vin c cu hi Mun ch to chi tit hnh 18.1 phi lm th no ? * HS : tr li * GV tng hp tr li ca hc sinh sau a ra quy trnh thc hin. Cho hc sinh tin hnh thc hnh

* Bc 5 : Tin phn tr 25, di 45mm

* Bc 6 : Tin tr 20, di 25mm

* Bc 7 : Vt mt 1 x 450

45

GV:NGUYN THANH TI

NM HC:2011-2012

* Bc 8 : Ct t chiu di 40mm

* Bc 9 : o u, vt mp 1 x 450

IV/ Tng kt nh gi : GV : nh gi tin hthn, thi hc tp v mc tip thu kin thc ca hc sinh thng qua qu trnh quan st trong gi thc hnh. GV : Yu cu hc sinh c trc bi 19 SGK.

46


NM HC:2011-2012

Bi 19: T NG HO TRONG CH TO C KH

Tit PPCT: 25

V. MC TIU 4. Kin thc: Hc sinh bit c cc khi nim v my t ng, my iu khin s, ngi my cng nghip v dy chuyn t ng. Cc bin php bo m s pht trin bn vng trong sn xut c kh. 5. K nng: Sng to, t duy khoa hc. 6. Thi : C thc bo v mi trng sng ca chng ta. VI. CHUN B 1 Chun b ca gio vin: + Nghin cu SGK v SGV. + c cc ti liu c lin quan n bi ging. + Tranh v cc hnh: 19.1, 19.2, v 19.3 SGK. 2 Chun b ca hc sinh: Lp quy trnh cng ngh ca mt chi tit. c trc bi hc 19 nh. VII. CC BC LN LP 4. n nh: n nh t chc lp. (2 pht) 5. Kim tra: Mt HS trnh by bi tp lp quy trnh cng ngh ca mt chi tit (trang 88 SGK). (13ph) 6. Bi mi: (30 pht) TL Ni dung c bn Hot ng thy tr 5ph I . MY T NG, NGI MY CNG H 1: Tm hiu v my t ng NGHIP V DY CHUYN T NG GV: Gii thiu cc khi nim v my t ng. 1 . My t ng: HS: Tip thu v ghi nhn khi nim. a) Khi nim: My t ng l my hon thnh GV: My t ng l g? c mt nhim v no theo mt chng trnh HS: Tr li cu hi. nh trc m khng c s tham gia ca con GV: Hy k tn cc loi my t ng m em ngi. bit? b) Phn loi: HS: Tr li cu hi. - My t ng cng: l my iu khin bng c kh nh cc c cu cam. - My t ng mm: l my c th thay i chng trnh hot ng d dng gia cng c cc loi chi tit khc nhau. H 2: Tm hiu v ngi my cng nghip 5ph 2 . Ngi my cng nghip: (rbt) a) Khi nim: Ngi my cng nghip (rbt) l GV: Trnh by khi nim v rbt v cng dng mt thit b t ng a chc nng hot ng theo ca rbt. chng trnh nhm phc v t ng ho cc qu HS: Tip thu v ghi nhn khi nim. trnh sn xut. GV: Rbt c cng dng g trong sn xut? b) Cng dng ca rbt: HS: Tr li cu hi. - Rbt c dng trong cc dy chuyn sn xut cng nghip. - Rbt thay th cho con ngi lm vic nhng mi trng nguy him v c hi. H 3: Tm hiu v dy chuyn t ng 5ph 3 . Dy chuyn t ng: GV: Gii thiu dy chuyn t ng (dng hnh Dy chuyn t ng l t hp ca cc my v cc v 19.3 SGK) 47

GV:NGUYN THANH TITL Ni dung c bn thit b t ng c sp xp theo mt trt t xc nh thc hin cc cng vic khc nhau nhm hon thnh mt sn phm no . II . CC BIN PHP M BO S PHT TRIN BN VNG TRONG SN XUT C KH 1 . nhim mi trng trong sn xut c kh: Du m v cc cht bi trn, lm ngui, ph thi trong qu trnh ct gt khng qua x l, a trc tip vo mi trng s gy nhim t v nc. 2 . Cc bin php m bo s pht trin bn vng trong sn xut c kh: - Pht trin bn vng l cch pht trin nhm tho mn cc nhu cu ca th h hin ti m khng nh hng n kh nng tho mn nhu cu ca th h tng lai. - Mun m bo s pht trin bn vng trong sn xut c kh cn phi xy dng v pht trin cc h thng sn xut xanh sch bng cch thc hin cc bin php sau y: + S dng cng ngh cao trong sn xut gim chi ph nng lng, tit kim nguyn liu . + C cc bin php x l du m v nc thi sinh ra trong qa trnh sn xut trc khi thi vo mi trng. + Gio dc thc bo v mi trng cho ngi dn.

NM HC:2011-2012Hot ng thy tr HS: Tip thu v ghi nhn. H 4: Tm hiu s nhim mi trng trong sn xut c kh GV: Em hy nu nhng v d v nhim mi trng trong sn xut c kh? HS: Tr li cu hi. GV: Em hy cho bit nguyn nhn v bin php khc phc cc hin tng nhim ? HS: Tr li cu hi. GV: Kt lun v nguyn nhn v bin php khc phc nhim mi trng trong sn xut c kh HS: Tip thu v ghi nhn kt lun. H 5: Tm hiu cc bin php m bo s pht trin bn vng trong sn xut c kh GV: Trnh by khi nim s pht trin bn vng. HS: Tip thu v ghi nhn khi nim. GV: Th no l s pht trin bn vng trong sn xut c kh? Em hy cho v d minh ho? HS: Tr li cu hi. GV: m bo s pht trin bn vng trong sn xut c kh cn phi xy dng v pht trin mt h thng sn xut xanh sch. Vy bin php thc hin l g? H 6: Cng c, giao nhim v v nh. GV: Hng dn HS tr li cc cu hi t 1 n 9 trang 91 SGK. GV: Tng kt, nh gi tinh thn, thi hc tp v s tip thu bi ca HS. Giao nhim v v nh: +c trc bi 20.

5ph

5ph

5ph

48


NM HC:2011-2012

PHN III: NG C T TRONG CHNG V: I CNG V NG C T TRONG Bi 20: KHI QUT V NG C T TRONGIV. Mc tiu: Sau khi hc xong bi ny hc sinh phi: - trnh by c khi nim v cch phn loi ng c t trong - trnh by c cu to chung ca ng c t trong V. Phng tin v phng php dy hc ch o: 1. Phng tin dy hc: - tranh v (hnh 20.1 sgk) - m hnh ng c 4 k 2. Phng php dy hc ch o: Vn p, thuyt trnh c minh ho v gii thch. VI. Cc hot ng dy hc 1. On nh lp: - Kim tra s s ca lp. 2. Ni dung bi mi: Hot ng 1: tm hiu s lc v lch s pht trin ng c t trong Hot ng ca gio vin v hc sinh + gv k mt vi mu chuyn lin quan n lch s pht trin ca ng c t trong + gv k thm thng tin v cc nh sng ch ra nhng loi ng c tin trn th gii + gv chia nhm, ngh cc nhm tho lunu, ghi tn gi nhng phng tin, thit b c s dng ng c t trong lm ngun ng lc v c mt i din bo co kt qa + gv nu khi qut vai tr v v tr ca ng c t trong trong sn xut v i sng, c th t cu hi: Ti sao tu thu khng dng ng c in lm ngun ng lc?

Tit PPCT: 26

Ni dung I. s lc lch s pht trin ca ng c t trong: + 1860 l nm ra i ca chic ng c t trong u tin trn th gii. l ng c 2 k, chy bng kh thin nhin do Ging Echin Lna ch to + 1877 Nicla Aogt Ott v Lng ghen ch to ng c 4 k chy bng kh than + 1985 Glip eml ch to ng c xng + 1897 Runph Sacl Sreing izen ch to ng c iezen + ngy nay, tng nng lng do ng c t trong to ra vn chim t trng rt ln trong tng nng lng c s dng trn ton th gii nn ng c t trong c v tr, vai tr quan trng trong tt c cc lnh vc sn xut v i sng

Hot ng 2: tm hiu khi nim v phn loi ng c t trong Ni dung II khi nim v phn loi ng c t trong 1. khi nim: + ng c t trong thuc loi ng c nhit hay ng c t trong l loi ng c nhit m qu trnh ng c in? t cht nhin liu sinh nhit v qu trnh bin i + ng c t trong bin nhit nng thnh in nng nhit nng thnh cng c hc din ra ngay trong xi 49 Hot ng ca gio vin v hc sinh

GV:NGUYN THANH TI

NM HC:2011-2012

hay c nng? lanh ca ng c + nhit nng ng c t trong c to ra bng 2. Phn loi: cch no? + ng c pittng, ng c tuabin kh, ng c phn lc + gv s dng tranh v gii thiu s lc v ng + ng c pittng chuyn ng tnh tin v pittng c tua bin v ng c phn lc chuyn ng quay + thng phn loi theo 2 du hiu ch yu: _ theo n hin liu: ng c xng, ng c iezen v ng c gaz _ theo s hnh trnh ca pittng trong mt chu trnh lm vic, c cc loi: ng c 4 k v ng c 2 k Hot ng 3: tm hiu cu to chung ca ng c t trong Hot ng ca gio vin v hc sinh Ngoi gii thiu tn gi ca cc c cu v h thng, hc sinh thy c nhim v, vai tr ca mi c cu, h thng, gio vin nn gi bng cch ngh hs tr li cc cu hi sau: + ti sao ng c li phi c c cu phn phi kh? + ti sao ng c li cn phi c cc h thng ? + ti sao ng c iezen khng c h thng nh la? Ni dung III> cu to chung ca ng c t trong: Cu to ca ng c t trong gm 2 c cu v 4 h thng chnh sau: + c cu trc khuu thanh truyn + c cu phn phi kh + h thng bi trn + h thng lm mt + h thng cung cp nhin liu v khng kh + h thng khi ng Ring ng c xng cn c thm h thng nh la

Ngy son:23-08 PPCT : 08 50

GV:NGUYN THANH TI

NM HC:2011-2012 Tit PPCT: 27-28

Bi 21: NGUYN L LM VIC CA NG C T TRONGMc tiu: Sau khi hc xong bi ny hc sinh phi: - Gii thch c mt s khi nim c bn v ng c t trong - Phn tch c nguyn l lm vic ca ng c t trong II. Phng tin v phng php dy hc ch o: 1. phng tin dy hc: - tranh v (hnh 21.1-21.2-21.3-21.4 sgk) - m hnh ng c 4 k v m hnh ng c 2 k loi 3 ca kh - v s nguyn l ng c 4 k v 2 k 2. Phng php dy hc ch o: Vn p, thuyt trnh c minh ho v gii thch. III. Cc hot ng dy hc 1. On nh lp: - Kim tra s s ca lp. 2. Ni dung bi mi: Hot ng 1: tm hiu mt s khi nim c bn I.

Ni dung I. mt s khi nim c bn: 1. mt s im cht ca pittng: im cht l v tr ca pittng m ti pittng i + im cht no th pittng cch xa (hoc gn) tm chiu chuyn ng. C 2 loi im cht: trc khuu nht? + im cht trn (CT) l im cht m pittng xa + khi pittng dch chuyn c mt hnh trnh th tm trc khuu nht trc khuu quan c bao nhiu ? + im cht di (CD) l im cht m pittng + hnh trnh S ca pittng ln gp bao nhiu ln bn gn tm trc khuu nht knh qua ca trc khuu? 2. hnh trnh pittng (S) Hnh trnh pittng l qung ng pttng di chuyn gia 2 im cht Khi pittng chuyn dch c mt hnh trnh th trc khuu s quay c mt gc l 180 . Nh vy nu gi R l bn knh quay ca trc khuu th S = 2R 3 3. th tch bung chy Vbc (cm hoc lt) Th tch bung chy l th tch xi lanh (th tch khng gian gii hn bi np my, xi lanh v nh pittng) khi pittng CT 4. th tch ton phn L th tch xi lanh khi pittng CD + khng gian bn trong xi lanh c gii hn bi 5. th tch cng tc nhng chi tit no? Sgk + ba th tch ni trn c mi lin h g vi nhau? 6. t s nn: + hy lp cng thc tnh th tch cng tc khi bit Sgk ng knh ca xi lanh bng D v hnh trnh ca 7. chu trnh lm vic ca ng c: pittng bng S Khi ng c lm vic, bn trong xi lanh din ra ln lt cc qu trnh: np, nn, chy gin n v thi., 51

Hot ng ca gio vin v hc sinh

GV:NGUYN THANH TI

NM HC:2011-2012

tng hp c 4 qu trnh y c gi l chu trnh lm vic ca ng c 8. k: K l mt phn ca chu trnh din ra trong thi gian + trong mt chu trnh lm vic ca ng c 4 k th mt hnh trnh ca pittng pittng dch chuyn c my hnh trnh? ng c 4 k l loi ng c m mt chu trnh lm + s khc nhau gia hnh trnh v k l g? vic c thc hin trong 4 hnh trnh ca pittng ng c 2 k l loi ng c m mt chu trnh lm vic c thc hin trong 2 hnh trnh ca pittng Hot ng 2: tm hiu nguyn l lm vic ca ng c iezen 4 k: Hot ng ca gio vin v hc sinh + hnh trnhf ny pittng i ln hay i xung? Ti sao? Do ci g tc ng? + hnh trnh ny xu pap no ng, xu pp no m? lm g? + ti sao k 3 li c gi l k sinh cng? + trong cc k cn li, pittng chuyn ng c l nh cng u? Hot ng 3: nguyn l lm vic ca ng c xng 4 k Ni dung 2. nguyn l lm vic ca ng c xng 4 k: + hy trnh by nguyn l lm vic cat ng c xng Nguyn l lm vic ca ng c xng 4 k cng 4 k? tng t nh ng c izen 4 k, ch khc 2 im + nguyn l lm vic ca hai loi ng c ging nhau sau: nhng im no>? + trong k np: kh np vo xi lanh ca ng c + nhin liu hoc ho kh hai loi ng c c iezen l khng kh cn ng c xng l ho kh. chm chy bng cch no? Ho kh ny c to bi b ch ho kh lp trn ng ng np + ci k nn, ng c iezen din ra s phun nhin liu cn ng c xng th bugi bt tia la in chm chy ho kh Hot ng 4: nguyn l lm vic ca ng c xng 2 k: Hot ng ca gio vin v hc sinh + hy trnh by nguyn l lm vic ca ng c xng 2 k v ng c iezen 2 k? + nu s khc nhau ca nguyn l lm vic ca 2 loi ng c ny? Ngy son:23-08 PPCT : 08 Ni dung III. nguyn l lm vic ca ng c 2 k 1. c im cu to ca ng c xng 2 k: sgk 2. nguyn l lm vic ca ng c xng 2 k:sgk IV nguyn l lm vic ca ng c iezen 2 k: Hot ng ca gio vin v hc sinh Ni dung II. nguyn l lm vic ca ng c 4 k: 1. nguyn l lm vic ca ng c iezen 4 k a. k 1 - np: sgk b. k 2 nn: sgk c. k 3 chy gin n d. k 4 thi

52

GV:NGUYN THANH TI NM HC:2011-2012 CHNG VI Tiet PPCT: 29 CAU TAO CUA ONG C OT TRONG Bai 22: THAN MAY VA NAP MAYI. Mc tiu : Qua bi dy ny, GV phi lm cho HS : - Bit c nhim v v cu to chung ca thn my v np my . - Bit c c im cu to ca thn Xilanh v np my ng c lm mt bng nc v bng khng kh . II. Chun b bi ging. 1. Chun b ni dung . - Nghin cu ni dung bi 22 SGK . - Tham kho thm cc thng tin c lin quan trong cc ti liu khc . 2. Chun b dng dy hc : - V tranh cc hnh 22.1, 22.2, 22.3. SGK . - M hnh ng c 4 k v 2 k . - Trong iu kin c th GV Chun b hoc yu cu HS su tm 1 s thn my v np my nhng ng c c nh, c ( V d : ng c xe my loi 2 k v 4 k ) III. Tin trnh bi dy : - Bc1 : T chc lp kim tra s s, n nh lp (1) - Bc 2 : Kim tra bi c (4) nu c - Bc 3 : Nghin cu kin thc mi ( 35) Thi lng 5 Ni dung bi dy I.Gi thiu chung : Thn my v np my l nhng chi tit c nh, dng lp cc c cu v h thng ng c. Cu to ca thn my rt a dng . Tu thuc mi loi ng c, thn my c th cu to lin khi hoc gm 1 s phn lp ghp vi nhau bng Bulng hoc Gu ging . Trong thn my, phn lp Silanh gi l thn si lanh, phn lp trc khuu gi l cacte hoc hp trc khuu, cacte c th ch to lin khi hoc chia lm 2 na : na trn v na di . 1 s loi ng c, na trn ca cacte c lm lin vi thn silanh , ng c xe my, cac te c chia thnh 2 na theo mt phng vung gc vi trc khu ca ng c Hot ng ca thy v tr *Hot ng 1 : Gi thiu chung v thn my v np my - GV S dng tranh v hnh 22.1 hoc m hnh, yu cu HS nhn bit v gii thiu cc phn chnh ca thn my v np my . - Trong hot ng ny, GV nn nhn mnh mt s ni dung sau : + Thn my v np my l ( khuu xng ) lp tt c cc c cu v h thng ca ng c + Thn my v np my l 2 khi ring nhng thn my c th lin hoc nhiu phn ghp li vi nhau. -Trong hot ng ny , c th s dng mt s cu hi sau : + Ti sao ni thn my v np my l (khung, xng ) ca ng c ? + Trn hnh 22.1 SGK th si lanh v trc khuu c lp phn no? - Gi tr li cu hi Cu 1 v tt c cc c cu v h thng ca ng c c lptrn . Cu 2 : Xilanh c lp phn thn xilanh cn trc khuu c lp phn cacte.

53

GV:NGUYN THANH TI10 II.Thn my : 1.Nhim v . Thn my dng lp cc c cu v h thng ca ng c . 2. Cu to thn my ph thuc vo s b tr cc xilanh, c cu v h thng ca ng c . Hnh dng c bn ca thn my c minh ho trn hnh 22.2 . Nhn chung cu to ca cacte tng i ging nhau . S khc bit ch yu l phn thn Xilanh . - Thn xilanh ca ng c lm mt bng nc c cu to khoan cha nc lm mt khoang ny c gi l o nc - Thn Xilanh ca ng c lm mt bng khnmg kh c cc cnh tn nhit . Xilanh c lp trong thn xilanh c dng hnh ng, mt tr bn trong c gia cng c chnh xc cao. Xilanh c th c lm ri ( Hnh 22.2b,d ) Hoc c lin vi thn Xilanh ( Hnh 22.2a,c )

NM HC:2011-2012Hot ng 2 : Tm hiu v cu to ca thn my . -GV s dng hnh 22.2 SGK yu cu HS nhn bit v gii thiu 2 loi thn my ng c lm mt bng nc v bng khng kh . - Trong hot ng ny phi gip HS hiu c ngoi nhim v dng lp Xilanh, thn xilanh cn c nhim v lm mt. V vy trn thn Xilanh c cu to o nc hoc cnh tn nhit . GV s dng cu hi nh sau : + ng c xe my thng lm mt bng g ? Cn c vo cu to b phn no c th ni nh vy ? + Ti sao trn cacte li khng c o nc hoc cnh tn nhit ? - GV gi tr li cu hi : - Cu 1: Bng khng kh . v bn ngoi thn Xilanh ( V c np Xilanh ) c cc cnh tn nhit . Cu 2 : V cacte xa bung chy nn nhit ca n khng cao n mc phi c b phn lm mt. *Hot ng 3: Tm hiu cu to ca np my . Trc ht GV Cn gip HS hiu c : +Nhim v chnh ca nm my l : cng vi xi lanh v nh pt tng to thnh bung chy ca ng c. + Ngoi ra, np my cn dng lp chi tit b phn nhBugi hoc vi phun, b tr cc ng ng np - thi b phn lm mt . -GV s dng H22.3 SGK gii thiu 1 np my ca ng c lm mt bng nc . - Tronh hot ng ny, GV s dng cc cu hi sau: + Ti sao trn np my cng phi c b phn lm mt? + Da vo du hiu no cho thy np my trn hnh 22.3 l np my ca ng c xng ? Gi tr li cu hi : + Cu 1 : V np my l 1 trong nhng p[hn to thnh bung chy ng c. Do vy khi ng c lm vic nhit ca np my rt cao. + Cu 2 : V trn c l lp Bugi

20

III. Np my 1.Nhim v : np my (cn gi l np Xilanh ) cng vi Xilanh v nh Pttng to thnh bung chy ca ng c . -Np my cn dng lp cc chi tit v cm chi tit nh Bugi hoc vi phun, 1 s chi tit ca c cu phn phi kh b tr cc ng ng np, thi o nc mt hoc cnh tn nhit .. 2. Cu to : ca np my tu thuc vo vic lp c b tr cc chitit v cm chi tit trn n . - Np my ng c lm mt bng nc dng c cu phn phi kh Xupap treo c cu to kh phc tp (H 22.3 ) do phi cu to o nc lm mt, cu to ng ng np thi v l Cc xu pp . Np my ng c lm mt bng khng kh dng c cu phn phi kh Xupp t hot ng c hai k thng c cu to n gin hn.

Bc 4 : Cng c ( 4 ) Hot ng 4 : Tng kt nh gi : - GV tng kt nhn mnh kin thc trng tm ca bi ( Nhim v, c im cu to ca thn my v np my ). 54

GV:NGUYN THANH TI

NM HC:2011-2012

- GV hng dn HS tr li cc cu hi cui bi 22 SGK v yu cu HS c trc bi 22 SGK. Bc 5 : Hng dn v giao nhim v nh (1)


Bai 23: C CAU TRUC KHUYU THANH TRUYEN

Tiet PPCT: 30

I/ MC TIU : 1/Kin thc : a-Bit c nhim v v cu to ca cc chi tit chnh trong c cu trc khuu thanh truyn . b-c c s cu to ca pt-tng ,thanh truyn v trc khuu 2/K nng : Rn luyn cc nng lc :So snh , phn bit chc nng v nhim v ca cc chi tit trong c cu tc khuu ,thanh truyn II/.CHUN B BI GING 1.Chun b ni dung -Nghin cu ni dung bi 23 SGKc 3 ni dung trng tm pt tng, thanh truyn, trc khuu -Tham kho cc thng tin c lin quan trong cc ti liu -Nghin cu cu to c cu (nu c vt tht ) 2.Chun b phng tin dy hc -Tranh v phng to cc hnh 23.1 , 23.2 ,23.3 v 23.4 SGK. -M hnh ng c t trong,vt tht III/DY KIN THC MI NOI DUNG I/Pt tng 1- Nhim v Cng vi xi lanh v np my to thnh khng gian lm vic, nhn lc y ca kh chy ri truyn lc cho trc khuu sinh cng v nhn lc t trc khuu thc hin cc qu trnh np, nn v thi kh 2-Cu to:Gm 3 phn chnh - nh c 3 dng + Bng + Li + Lm - u : c lp xec mng kh v du .y rnh xec mng du c l nh thng vo bn trong - Thn: Dn hng cho pt tng chuyn ng trong xi lanh thn pt tng c l ngang HOAT ONG DAY VA HOC *Hot ng I:Gii thiu chung v c cu trc khuu thanh truyn -Gio vin: Em hy cho bit pt tng, thanh truyn, trc khuu dc sd dng ng c no? Hc sinh: tr li:ng c t trong -G V:C cu trc khuu thanh truyn c chia lm my nhm? H S:Tr li:3 nhm -G V:Cc em i tm hiu c im cu to v nhim v ca tng nhm trong c cu ny: *Hot ng II:Tm hiu pt tng G V:a ra mu vt pt tng xe my cho hc sinh quan st:v t cu hi:nh,u,thn pt tng c nhim v g? H S:Tr li : 55

GV:NGUYN THANH TIII/Thanh truyn 1- Nhim v Thanh truyn l dng truyn lc gia pttng v trc khuu 2- Cu to:Gm 3 phn -u nh:c dng hnh tr rng lp cht pt tng -Thn:ni u nh vi u to,thn c tit din ngang hnh ch I -u to:lp vi cht khuu,c th lm lin khi,hoc ri hai na .Hai na ri c ghp bng bu lng ,bn trong c bc lt hoc bi III/Trc khuu 1-Nhim v:Nhn lc t thanh truyn to ra m men quay ko my cng tc v dn ng cc c cu h thng ca ng c 2-Cu to:Ty thuc vo loi v kch c ca ng c Cu to gm:u- ui- thn phn thn ca trc khuu gm:c khuu, cht,mv i trng,m v i trng c th lin hoc ri.Cn ui trc khuu c lp vi bnh

NM HC:2011-2012G V:nh pt tng c my dng H S:Tr li *Hot ngIII:Tm hiu thanh truyn G V:Thanh truyn trong ng c t trong c nhim v g?v hnh dng ca chng c cu to nh th no? H S:Tr li G V:Ti sao u nh v u to ca thanh truyn li phi lp bc lt hoc bi? H S:Tr li ( quan st hnh23.3) *Hot ng IV:Tm hiu trc khuu -G V:Cc em hy quan st hnh 23.4 v cho bit tn cc chi tit ca trc khuu -H S:Tr li -G V:Vy trc khuu ca ng c c cu to nh th no? H S:Tr li -G V:Trc khuu c nhim v g? -H S:Tr li -G V:Trn m khuu lm thm i trng lm g? -H S:Tr li *Hot ngIV: -G V:Cng c trng tm bi dy hng dn hc sinh tr li 3 cu hi cui bi


Bi 24: C CU PHN PHI KH

Tit PPCT: 31

I/ Mc tiu. Gip hc sinh: - Bit c nhim v, cu to chung v nguyn l lm vic ca c cu phn phi kh. - c c s nguyn l ca c cu phn phi kh dng xupap. II/ Chun b. Tranh v phng to cc hnh 24.1 v 24.2 SGK. III/ T chc hot ng dy hc. 1. n nh lp (1). 2. Kim tra bi c ( 4). Nu nhim v v cu to ca pit-tng. 56

GV:NGUYN THANH TI3. Bi mi. TG Hot ng - V: Kh, nhin liu c a vo xilanh 10 nh CCPPK => tm hiu hot ng ca c 5 cu ny. - Khi ng c lm vic cc ca np, thi c m lin tc khng? - GV kt lun v nu nhim v. 5

NM HC:2011-2012Ni dung I/ Nhim v v phn loi. 1. Nhim v. ng, m cc ca np, thi ng lc ng c thc hin qu trnh np kh mi vo xi lanh v thi kh chy trong xi lanh ra ngoi. 2. Phn loi. - CCPPK dng xupap: + Dng xupap t. + Dng xupap treo. - CCPPK dng van trt. II/ C cu phn phi kh dng xupap. 1. Cu to. - Cc chi tit chnh trong CCPPK xupap treo: trc cam v cam, con i, a nay, c m, xupap v l xo xupap. Trong mt chu trnh lm vic ca ng c 4 k, xupap m mt ln nn cam ch c moat vu v s vng quay ca trc cam ch bng s vng quay ca truc khuu. - CCPPK xupap treo c xupap c lp np trn my, cn CCPPK xupap t c xupap c lp thn xilanh. 2. Nguyn l lm vic. ( SGK) -

27 15 - Yu cu HS quan st hnh v 24.2a,b v tr li cu hi: + K tn cc chi tit chnh trong CCPPK xupap treo? + Mi cam trn trc cam dn ng c my xupap? (mt) - Hng dn HS tho lun tr li cc cu hi trong SGK.

12 - Yu cu HS nghin cu SGK v nu nguyn l lm vic ca CCPPK xupap treo, t => nguyn l ca CCPPK xupap t. - GV kt lun.( ch CCPPK xupap t con i tc ng trc tip vo xupap). 4. Tng kt ( 3). - GV tng kt nhng kin thc trng tm ca bi. - Hng dn hc sinh tr li cc cu hi cui bi trong SGK. - Yu cu HS c trc bi 25. CU HI TRC NGHIM Cu 1: Du hiu ch yu phn bit CCPPK xupap t v CCPPK xupap treo lCCPPK xupap t c xupap c lp . . . cn CCPPK xupap treo c xupap c lp . . . . A. thn xilanh; np trn my. B. np trn my; thn xilanh. C. trc cam; trc khuu. D. trc khuu; trc cam. 57

GV:NGUYN THANH TICu 2: Trong CCPPK dng xupap: A. S vng quay ca trc khuu bng s vng quay ca trc cam. B. S vng quay ca trc cam bng s vng quay ca trc khuu. C. S vng quay ca trc khuu bng s vng quay ca trc cam. D. Khng so snh c. Cu 3: CCPPK c chia thnh 2 loi l CCPPK dng v CCPPK dng

NM HC:2011-2012


Bi 25: H THNG BI TRN

Tit PPCT: 32

A-MC TIU: *Qua bi hc hc sinh bit c : - Nhimv ca h thng bi trn; cu to chung v nguyn l lm vic ca h thng bi trn cng bc. - Hc sinh c c s nguyn l ca h thng bi trn cng bc. B- CHUN B : 1-Chun b ni dung: *Gio vin : - Nghin cu ni dung bi H thng bi trn -Tham kho thm cc thng tin c lin quan trong cc ti liu. * Hc sinh : - c bi H thng bi trn ,tm cu tr li cc cu hi cui bi hc - V s h thng bi trn cng bc vo v, nghin cu hot ng ca du trong h thng. 58

GV:NGUYN THANH TI

NM HC:2011-2012

-Tm v pht hin cc ni dung khng hiu lin quan n hthng bi trn cng Bc. 2 Chun b phng tin dy hc: -V hnh 25.1 vo giy A0.

Hoc v s khi thay th Hnh 25.1

59

GV:NGUYN THANH TI

NM HC:2011-2012Cc b mt ma st cn bi trn

Kt lm m t Bu lc du Bm du

Cacte du

Mch du chnh Mch du hi, du qua kt lm mt, du t bu lc v cacte. C- TIN TRNH BI GING: 1-n nh t chc lp:(01 pht) 2- Kim tra bi c: a Em hy trnh by nhim vk ca h thng phn phi kh? (05pht) b - Trnh by nguyn l lm vic ca c cu phn phi kh xupp t? c Em hy so snh u im ca c cu phn phi kh xu pp treo vi c cu phn phi kh xupp t trong qu trnh se dng? 3-Hot ng dy hc: *Thi lng: *Ni dung: *Hot ng ca thy v hot ng ca tr: I: NHIM V V PHN LOI: 1 - Nhim v : Bi trn, lm mt, ty ra GV: V sao khi ng c hot ng b nng ln? 5 pht Bao ph chi tit v chng r, chng mi mn -Khi hot ng cc b mt ma st cc chi tit 2 Phn loi :Bi trn cng bc, vung t trt ln nhau gy ra hin tng g? Pha du bi trn vo nhin liu... -Mun hn ch cc nhc im trn ng c phi c h thng gi? II-H THNG BI TRN CNG BC -C nhng phng php bi trn no? 1-Cu to: Hnh 25.1 HS: Tr li theo gi ca gio vin. 15 pht Gm cc b phn chnh ( SGK) GV: -Gii thiu bn v cu to h thng bi trn cng bc HS-Quan st s cu to, ngin cu cc ni dung sch gio khoa v cu to h thng b trn cng bc. 2- Nguyn l lm vic GV: H thng bi trn cng bc gm nhng b -S dng s khi gii thiu phn chnh no? 15 pht -Theo em mi b phn c nhim v ring ca Hot ng ca h thng ( SGK) n, em gii thiu N/V b phn em bit? -Khi ng c hot ng du c a ti bi trn nhng chi tit, b phn no ca ng c? -Ti sao? trong h thng phi s dng bm du. HS: Tr li cu hi ca GV . 60

GV:NGUYN THANH TI

NM HC:2011-2012GV: Gi thiu tm hiu h thng bi trn hn hp, bi trn vung t, bi trn bng phng php ho trn du bi trn vo nhin liu... GV: t cc gi thit cc ng ng du b tc, du khng lu thng phi x l nh th no? GV: Nhc li nhim v ca h thng bi trn. - S khi v h thng bi trn cng bc, v hot ng ca du trong h thng. -GV : Yu cu HS Chun b bi cho tit hc tip Theo v H thng lm mt ch cc cu hi cui bi v b sung cc cu hi theo ni dung bi hc.

04 Pht

D-CNG C BI DY:

CU HI TC NGHIM: CU 1: -Du bi trn dng cho ng c c tc dng g? AChng mi mn cc b mt chi tit, tn nhit, chng r, bao kn v ra chi tit. BGim ma st, gip cc chi tit hot ng lin tc khi ng c hot ng. CTng cng sut ng c, gim tiu hao nhin liu, chng nhim mi trng. DChuyn ma st kh gia cc b mt ma st sang ma st t , chi tit c tui th cao hn. CU 2:- Ti sao trong h thng bi trn cng bc phi s dng bm du? A - To cho du lu thng trong h thng nhanh hn. B - Tn nhit cho cc chi tit c trit C - a du bi trn n cc b mt ma st c tt. D Bo v cc chi tit v chng r. CU 3 : Trong ba b phn : Bm du, bu lc du, kt lm mt du th b phn no quan trng nht trong h thng bi trn ? AKt lm mt du. BBm du. CBu lc du. DC ba b phn trn.

Ngy son:23-08 61

GV:NGUYN THANH TIPPCT : 08

NM HC:2011-2012

Bi 26: H THNG LM MT

Tit PPCT: 33

IV. Mc tiu: Sau khi hc xong bi ny hc sinh phi: - Trnh by c nhim v, cu to v nguyn l lm vic ca h thng lm mt - c c s h thng lm mt bng nc loi tun hon cng bc V. Phng tin v phng php dy hc ch o: 1. phng tin dy hc: - tranh v (hnh 26.1-22.2-26.3 sgk) - thn xi lanh v np my ng c xe my (lm mt bng khng kh) - phn mm m phng s cu to v nguyn l lm vic ca HTLM loi tun hon cng bc v phng tin trnh chiu 2. Phng php dy hc ch o: Vn p, thuyt trnh c minh ho v gii thch.

VI. 1. On nh lp: - Kim tra s s ca lp. 2. Ni dung bi mi: Hot ng 1: tm hiu nhim v v phn loi h thng Hot ng ca gio vin v hc sinh + s cn thit ca vic lm mt ng c + nhit ca cc chi tit qu thp cng gy nh hng ti cng sut ca ng c + ti sao cn phi lm mt ng c? + trong ng c vng no cn lm mt nhiu nht?

Cc hot ng dy hc

Ni dung I. Nhim v v phn loi: 1. Nhim v: H thng lm mt nhim v gi cho nhit ca cc chi tit khng vt qu gii hn cho php 2. Phn loi: Theo cht lm mt, h thng c chia ra lm 2 loi: + h thng lm mt bng nc + h thng lm mt bng khng kh

62

GV:NGUYN THANH TIHot ng 2: tm hiu v cu to ca h thng lm mt cng bc: Hot ng ca gio vin v hc sinh + gv hng dn hc sinh tm hiu trn hnh 26.1 sgk

NM HC:2011-2012

Ni dung II. H thng lm mt cng bc: 1. cu to: H thng lm mt bng nc chia ra 3 loi: bc hi, i lu t nhin, tun hon cng bc. H thng tun hon cng bc bao gm: bm nc, kt nc, qut gi, van hng nhit, cc ng ng dn nc.

Hot ng 3: tm hiu nguyn l lm vic ca h thng lm mt bng nc: Hot ng ca gio vin v hc sinh + gv hng dn trn hnh v 26.1 Ni dung 2. nguyn l lm vic: Bm nc ht nc t ngn nc c nhit thp + gv v hnh nguyn l , s khi h thng lm mt ca kt v a ti cc o nc lm mt. Sau nc bng nc ln bng s theo cc ng ng tr v pha trc van hng + hc sinh v hnh vo v v t ghi nhit. Nu nhit ca nc di nhit cho php th van hng nhit m cho nc v pha trc bm. Nu nhit qu cao, van hng nhit s m cho nc v kt Hot ng 4: tm hiu h thng lm mt bng khng kh Hot ng ca gio vin v hc sinh Ni dung + gv s dng hnh v 26.2 v 26.3 sgk III. h thng lm mt bng khng kh: + gv v hnh nguyn l h thng lm mt bng khng 1. cu to: kh Ch yu l cnh tn nhit c c bao ngoi thn xi lanh v np my. Qut gi, tm hng gi 2. nguyn l lm vic: Nh cnh tn nhit din tch tip xc ca ng c vi khng kh tng ln nh khng kh s ly bt nhit ca ng c Cng c bi hc: Cu 1: bm nc dng lm g? Cu 2: qut gi trn h thng lm mt bng nc dng lm g? Cu 3: xt di gc lm mt ym xe my c tc dng nh th no?

Ngy son:23-08 PPCT : 08 63

GV:NGUYN THANH TI NM HC:2011-2012 Bi 27: H THNG CUNG CP NHIN LIU V KHNG KH Tit PPCT: 34 TRONG NG C XNGNgy son:23-08 PPCT : 08

Bi 28: H THNG CUNG CP NHIN LIU V KHNG KH TRONG NG C IEZEN

Tit PPCT: 35

I. MC TIU: 1. Kin thc: GV cn lm cho HS: Bit c nhim v, cu to chung v nguyn l lm vic ca h thng cung cp nhin liu v khng kh trong ng c izen. 2. K nng: c c s khi ca h thng. II. CHUN B: GV: Son bi chu o, tham kho thm cc thng tin c lin quan trong cc ti liu, tranh v phng to hnh 28.1 SGK v s cu to ca h thng c cc b phn chnh. HS: Xem trc bi mi. III. CC BC LN LP: 1. n nh lp: ( 1 pht ) 2. Kim tra bi c: ( 7 pht ) Cu hi : 1. Trnh by s v nguyn l lm vic ca h thng nhin liu dng b ch ho kh. 2. Trnh by s v nguyn l lm vic ca h thng phun xng. 3. Ging bi mi: 1. Hot ng 1: Tm hiu nhim v ca h thng. ( 5 Pht ) NI DUNG C BN HOT NG CA THY V TR I.Nhim v ca h thng v c im ca s hnh thnh ho kh ng c iezen. GV: Nhim v ca h thng cung cp nhin liu 1. Nhim v ca h thng: l g? Cung cp nhin liu v khng kh sch vo xi HS: c SGK v tr li. lanh ph hp vi cc ch lm vic ca ng c. 2. Hot ng 2: Tm hiu c im ca s hnh thnh ho kh. (7 pht) NI DUNG C BN HOT NG CA THY V TR 2. c im ca s hnh thnh ho kh: - Nhin liu c bm cao p phun ti vo xi GV: V sao nhin liu phi c phun ti ? lanh ng c cui k nn. GV: Trong chu trnh lm vic ca ng c, nhin - Cc ch lm vic ca ng c hon ton tu liu c phun vo thi im no? thuc vo lng nhin liu cp vo xi lanh trong GV: So vi ng c xng, thi gian ho trn mi chu trnh. nhin liu izen di hn hay ngn hn? 3. Hot ng 3: Tm hiu cu to v nguyn l lm vic ca h thng. (20 pht) II. Cu to v nguyn l lm vic: GV: Treo tranh hnh 28.1 SGK gii thiu cu to 1. Cu to: (treo hnh 28.1. S khi h thng ca h thng. GV: c sch v cho bit nhim vu ca cc b nhin liu ng c izen ) phn chnh? - Thng nhin liu dng cha nhin liu. HS: c sch v tr li. - Bu lc th: dng lc du. GV: Nu khng c bm chuyn nhin liu, cn 64

GV:NGUYN THANH TIBm chuyn nhin liu: chuyn du t bu lc th sang bu lc tinh. - Bu lc tinh: lc sch cc cn bn c kch thc rt nh ln trong nhin liu. - Bm cao p: cung cp nhin liu vi p sut cao, ng thi im v lng ph hp vi ch lm vic ca ng c ti vi phun phun vo xi lanh ng c. - Vi phun: phun ti nhin liu vo xi lanh. 2. Nguyn l lm vic: k nn ch c kh trong xi lanh b nn. Nhin liu c bm ht t thng nhin liu, c lc qua cc bu lc th v tinh ri a ti khoang cha ca bm cao p. Cui k nn, bm cao p bm mt lng nhin liu nht nh vi p sut cao vo vi phun phun vo xi lanh ng c. Nhin liu ho trn vi kh nn to thnh ho kh ri t bc chy. -

NM HC:2011-2012lm th no h thng vn lm vic c? HS: phi t thng nhin liu cao hn bm cao p mt khong no nhin liu t chy xung bm cao p. GV: Trong h thng, b phn no quan trng nht? HS: bm cao p. GV: Hy trnh by tm tt nguyn l lm vic ca h thng? HS: Du c bm ht t thng cha qua bnh lc th v y ti bnh lc tinh. Sau khi lc sch, du c sang bm cao p. Ti y du c nn vi p sut cao v a sang vi phun. Cui hnh trnh nn, vi phun s phun du vo xi lanh di dng nhng ht nh mn, ho trn cng khng kh to thnh hn hp. Di tc dng ca p sut cao, nhit ln, hn hp ny t bc chy sinh cng.

4. Hot ng 4: Tng kt, nh gi. (5 pht) - GV tng kt, nhn mnh kin thc trng tm ca bi. - GV hng dn HS tr li cc cu hi cui bi 28 SGK, yu cu HS c trc bi 29 SGK.

CU HI:Cu 1: Trong chu trnh lm vic ca ng c, nhin liu c phun vo thi im no? Cui k nn. u k nn. Cui k ht. u k x. Cu 2: So vi ng c xng, thi gian ho trn nhin liu izen di hn hay ngn hn? Ngn hn. Bng nhau. Di hn. Khng xc nh c. Cu 3: Trong h thng cung cp nhin liu v khng kh trong ng c izen, b phn no quan trng nht? Bm cao p. Vi phun. Thng nhin liu. Bm chuyn nhin liu. Cu 4: Trong h thng li c thm bu lc tinh l lc sch cc cn bn c kch thc rt nh ln trong nhin liu.

Ngy son:23-08 PPCT : 08 65

GV:NGUYN THANH TI Bi 29: H THNG NH LANgy son:23-08 PPCT : 08

NM HC:2011-2012 Tit PPCT: 36

Bi 30: H THNG KHI NG

Tit PPCT: 37

I/ Mc tiu : 1. Kin thc : Nu c nhim v, cu to v nguyn l lm vic ca h thng khi ng bng ng c in. 2. K nng : Phn loi c h thng khi ng. II. Chun b 1. Gio vin : - Tranh 30.1 (sgk). - My khi ng in dng cho ng c t trong trn t (nu c). 2. Hc sinh : - N/cu trc ni dung bi 30 SGK III. Cc bc ln lp 1. n nh lp : (2), kim tra s s. 2. Kim tra bi c : (5). Gv nu cu hi : Trnh by nhim v v nguyn l lm vic ca h thng nhin liu ng c iezen. 3. T chc hot ng dy hc T Lng Ni dung c bn I. Nhim v v phn loi 1. Nhim v HTK c nhim v lm quay trc khuu ca ng c n s vng quay nht nh ng c t n my 2. Phn loi : (c 4 loi ) - H thng khi ng bng tay - HTK bng ng c in - HTK bng ng c ph - HTK bng kh nn II. HTK bng ng c in 1. Cu to : (Hnh 30.1 sgk) - Gm c 4 b phn chnh + ng c in 1 chiu + C cu truyn ng + Rle khi ng +Acquy 2. Nguyn l lm vic - Khi khi ng ng c c in nn roto ca ng c in quay lm khp truyn ng cng bnh rng ca n quay theo. Li thp ca rle dch chuyn sang tri qua cn gt s y bnh rng ca khp n khp vi bnh rng trn bnh ng c. 66 Hot ng ca thy v tr H1 : Tm hiu nhim v v phn loi h thng. - Tm hiu nhim v ca h thng. + GV : Yu cu nu mt s cch khi ng ng c t trong. + HS : Tr li. + NX : Cc hc sinh cn li +GV : NX v b sung Gii thiu nhim v ca h thng - Tm hiu v phn loi h thng + GV : Chng ta c my cch khi ng xe gn my ? + HS : Tr li + GV : Khi ng ng c bng tay thng s dng ng c c cng sut ln hay nh ? + HS :Tr li + GV : Gii thiu v phn loi h thng khi ng. H 2 : Tm hiu cu to ca HTK bng ng c in. - GV : S dng hnh v gii thiu cu to cc b phn chnh ca h thng. Gii thch : cu to v vai tr ca Rle, s

13

20

GV:NGUYN THANH TIMmen quay t ng c in truyn ti trc khuu, ng c s n my. - Khi tt kho khi ng Rle mt in cc chi tit ca h thng tr v v tr ban u

NM HC:2011-2012lin kt gia cc khp truyn ng vi trc ca Rto ng c in. - HS : Quan st v ghi nhn H 3 : Tm hiu nguyn l lm vic ca h thng khi ng bng ng c in. - GV :S dng hnh v 30.1 gii thiu nguyn l lm vic ca h thng. Nu cu hi : Rto quay khp truyn ng c quay khng ? ti sao? Gi tr li cu hi trn. -HS : Tr li - GV : Khp truynd ng dch chuyn sang phi nh b phn no ? - HS : Tr li H 4 : Tng kt nh gi -GV : Tng kt kin thc trng tm ca bi. Hng dn hc sinh tr li cu hi sgk trang 130. chun b dng c cho bi thc hnh


Bi 31:Thc thnh: TM HIU CU TO CA NG C T TRONG

Tit PPCT: 38-39


KIM TRA MT TIT

Tit PPCT: 40

Ngy son:23-08 PPCT : 08 67

GV:NGUYN THANH TI

NM HC:2011-2012 Tit PPCT: 41

CHNG VII NG DNG NG C T TRONG Bi 32: KHI QUT V NG DNG CA NG C T TRONG

I MC TIU: Dy xong bi ny, GV cn lm cho HS: Bit phm vi ng dng ca CT. Bit c nguyn tc chung v ng dng CT. II CHUN B BI DY: 1. Chun b ni dung Nghin cu k bi 32SGK v cc ti liu c lin quan. 2. Chun b phng tin dy hc Phng to tranh v hnh 32.1, 32.2 SGK III TIN TRNH T CHC DY HC: 3/ 1. n nh lp Kim tra s s vng, kim tra trang phc. 2. Ni dung bi dy t vn : Trong thc t cc em c bit, CT c ng dng nh th no? Ni dung bi 32: Khi qut v ng dng ca CT.

68

GV:NGUYN THANH TITG 17/ 18/

NM HC:2011-2012

7/

Hat ng ca thy v tr Ni dung c bn I- VAI TR V V TR CA NG C Hat ng 1: Tm hiu v vai tr v v T TRONG tr ca CT trong sn xut v i sng - GV: ng c t trong c s dng ph 1.Vai tr ng c t trong l ngun ng lc c bin trong cc lnh vc no? s dng ph bin trong cc lnh vc cng - HS: Cc em tm hiu trong thc t tr li nghip, nng nghip, lm nghip, ng nghip, giao thng vn ti, qun s, 2.V tr Hin nay, trong cc thit b ng lc tng - GV: Treo tranh v hnh 32.1 SGK. Hy k tn mt s phng tin, thit b cng sut do CT to ra chim t trng ln v cng sut thit b ng lc do mi ngun nng khc c s dng CT m em bit. lng to ra ( nhit nng, thy nng, nng - HS: Xem tranh v v lin h thc t tr li. - GV: Hin nay cng sut CT to ra chim lng nguyn t, nng lng mt tri ) v tr nh th no? II- NGUYN TC CHUNG V NG DNG - HS: Xem SGK tr li Hat ng 2: Tm hiu nguyn tc NG C T TRONG 1. S ng dng: chung v ng dng CT - GV: Treo tranh v hnh 32.2 SGK. ng c H thng My - GV: CT thng s dng lai ng c no? cng t truyn - HS: Xem SGK tr li. tc trong lc - GV: My cng tc gm nhng lai my no? - ng c t trong lm vic, to ra momen - HS: Da vo thc t bit v SGK tr li. quay u trc dn ng qua h thng truyn - GV: V sao my cng tc hat ng c? lc lm quay my cng tc. - HS: Da vo s tr li. - GV gii thch: H thng truyn lc l khu ni trung gian gia CT v my cng tc. Kt cu ca h thng truyn lc ph thuc vo yu cu, nhim v, iu kin lm vic ca my 2. nguyn tc ng dng ca ng c t cng tc trong - GV: my cng tc hat ng bnh thng - CT lm ngun ng lc cho my cng tc cn tun th cc nguyn tc sau: th CT phi chn nh th no? - HS: CT c la chn phi p ng yu + V tc quay: cu v cng sut cng nh tc quay ca my Tc quay ca ng c bng tc cng tc. quay ca my cng tc, cn ni trc tip qua khp ni. Tc quay ca chng khc nhau, cn p

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