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24
15 6 Body Development Dept. Vehicle Develop Div.
No.322015
SKYACTIV-BODY Development of SKYACTIV-BODY Structure for New Roadster
1 2 3 Takayuki Kimura Katsunori Sakai Kazuki Yamauchi
4 5 6 Kenji Maruyama Taiki Yotsuyanagi Yasuhisa Okazawa
CX-5SKYACTIV-BODYFRNVH
NVH
3217kg2230kg211kg197kg
Summary New Roadster is a product that is made by getting back to basics of Roadster Everybody can enjoy
and focused on improving Jinba-Ittai performance. Following CX-5AtenzaAxela, FR open body structure is applied the same approach of SKYACTIV-BODY and aimed to improve handling and stability, crash safety and NVH performance by lighter weight than the first Roadster. And we aimed to embody the beautiful sporty styling and a feeling of vitality by design theme KODO: SOUL of MOTION.
Consequently, body stiffness (fundamental of handling and stability and NVH performance) and crash safety are improved and the weight of body in white results in 197kg (3rd Roadster 217kg, 2nd Roadster 230kg, 1st Roadster 211kg) which is the lightest weight in open car segment. This paper outlines development activities for a light weight open body structure
1.
4FR
NVH
NVH
1989
2.
2.1 SKYACTIV-BODY(1)
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No.322015
PPF FF4WD &
2.2
Fig. 1
Fig. 1 SKYACTIV-BODY Vision 2.3 NVH
Fig. 2 topology
Fig. 2 Topology Analysis
3.
3.1 3
780MPa4
780MPa440MPa1.6t 1.2t / 1.4t
CAE
Fig. 3
Fig. 3 Front Frame Structure
3.2
2.3
FF Next-FRFront engine Front drive
Closed BodyFront engine Rear drive
Open Body1
3
1
3
33
2
Twisting Condition Bending Condition
Connect Front Suspension Tower to Backborn Frame
CAE Model
OPTIMIZATION
Crushable Zone
Suspension Tower
Axial compression force
Cross-shaped Frame
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No.322015
Fig. 41500MPa5
Fig. 4 Dash Cross Member
3.3
SKYACTIV-BODY
ONE MAZDA 1
Fig. 5
Fig. 5 High Mount Backbone Frame1
2
Fig. 6
Fig. 6 High Mount Backbone Frame2
3.4
1
30 Fig. 7
Fig. 7 Side-Sill
3.5
90mm
SKYACTIV-BODY
New Model
Previous Model
Hole in the section Separated a section and hole
New ModelPrevious Model
Steering shaft through hole
Mildly-curveCurvature
Curvature Mildly-curve
New ModelPrevious Model
Plan View
Side View
Plan View
Side View
ContinuousDiscontinuous
New ModelPrevious Model
Previous Model New Model
Not Verticality to Input Direciton Verticality to Input Direciton,So Hold On
Input
Strength
InputStrength
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Fig. 8
Fig. 8 Rear-Side Frame
3.6
112gFig. 9
Fig. 9 Lid-Filler
4.
Fig. 10
Fig. 10 Weld Bond
5.
5.1 Multi-
disciplinary Design OptimizationMDO6CAE
Fig. 119801180MPa1500MPa
Fig. 125862
Fig. 11 High-Tensile Steel Usage Rate
Fig. 12 Occupant Protection
New Model
Previous Model Al Hot Stamp 1180MPa 980MPa 780MPa 590MPa 440/390MPa 270MPa
0% 20% 40% 60% 80% 100%
High-Tensile Steel Double-HAT
Push LifterLift Spring
Actuater
Stopper BracketFemale Hinge Spring
Lid PanelShaft
Hinge Bracket
New Component Parts
Previous Model
New Model
Weld bonded sections
SAFETY ZONE
SAFETY ZONE
Hot Stamp 1180MPa 980MPa
Front
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5.2 1180MPa1500MPa
ONE MAZDAFig. 13
Fig. 13 Hot Stamp Material
6. CAE
6.1
CAE
Fig. 14
Fig. 14 Front Body Structure
Fig. 15
Fig. 15 Rear Body Structure
Fig. 16
Fig. 16 Front Suspension Body Structure 6.2 MDO
NVH
MDO
3.9kg
1180MPa High Tensile Steel
Compression ForceHot Stamp
Previous Model New Model
Input Input
Input
New ModelSide View
Front View
SUSPENSIONTOP
LOAD DISPERSING
SUSPENSIONTOP
STRUT TOWER BAR
SIDE SILL
SIDE SILL
Previous Model New Model
SUSPENSION FIXED POINT
BRACE
LOAD DISPERSING
SIDE SILL
Previous Model New Model
PACKAGE
InputInput
LOAD DISPERSING
SUSPENSIONTOP
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MDO340gFig. 17
Fig. 17 MDO Application
7.
7.1
Table 1
Table 1 Stiffness
7.2
NCAP
7.3 SKYACTIV-BODY
FR
3217kg2230kg211kg197kgFig. 18
Fig. 18 Body in White Weight Per Projected Area
3248kg225kg
8.
SKYACTIV-BODY
1SKYACTIV-Body No.29pp.61-672011 2No.24pp.66-712006
Bod
y w
eigh
t [kg
]
Vehicle plane area [m2]
Previous model3rd Roadster
JPN - A
EU - A
BICBest in class line
New modelJPN - B
1st Roadster
Large
Light
2nd Roadster
PreviousModel
NewModel
Torsional Stiffness 100% 109%
Front Damper Stiffness 100% 119%
Rear Damper Stiffness 100% 117%
132 Parts primarily in under body at 1st MDO (below left side)
54 Parts primarily in under body at 2nd MDO (below right side)
http://www.mazda.com/contentassets/caf0e8a523d64cd7b30b10f7c762b3ea/files/2011_no012.pdfhttp://www.mazda.com/contentassets/caf0e8a523d64cd7b30b10f7c762b3ea/files/2011_no012.pdfhttp://www.mazda.com/contentassets/efa12b3f26b4485c89b89ae0ef1b5ec2/files/2006_no014.pdf