Hood Assembly

OBJECTIVE

• Design Outer Panel with the Hem
• Develop the Inner Panel
• Develop all the Necessary Reinforcements
• Mirror and position the Hinge & Striker
• Provide Mastic Data
• Provide the required Emboss definition

HOOD ASSEMBLY

A car hood is the metal part that covers the engine of an automobile.Hood Assembly consists of Hood inner Panel, Hood Outer panel, Reinforcement panels, Striker, Hinge,Mastics and Wiping system. Below is the pic of Hood Assembly designed.

HOOD INNER

Hood Inner panel is the main structure of the hood assembly. This part adds stiffness to the Vehicle to with stand the frontal crash and has provision to hold hinge, Stopper and striker. It has embossing to add more stiffness to the part and cutout to reduce the overall weight. It has mastics to be fixed to the Hood Outer panel.

HOOD INNER EMBOSSING

Embossing is done to add more stiffness to the panel. Adding embossing will add more strength and stiffness to the part. The embossing value must be optimum to ensure all the part requirement such as manufacturing feasiblity, Frontal crash requirements and Pedestrian crash requirements.

• 40mm Hollow body given near Striker and stopper region for more crushable zone above hard part for pedestrian performance.
• 8mm clearance with Hood outer for Mastic zone.

HOOD OUTER HEMMING

Hemming is an Operation used to fixed two panels together. Hood Outer is fixed to Hood inner by hemming Operation.

Hemming Operation is not done at hood corners to avoid wrinkling of sheet metal.

Hood Striker

Hood striker is the part which is used to fix the Hood assembly with the latch. The Hood striker must be positioned in such a way so that the striker is perpendicular to path of Hood trajectory.

Since this zone is load bearing area additional reinforcement is provided to have more stiffness.

Section Analysis

Section Analysis is done to understand the Load bearing capacity of the panel before CAE analysis. MOI is measured along the principle axis to understand the characteristics of the panel.

• Max MOI 4.9 * 10^4 mm4 about Y axis (More stiffness for Frontal crash)
• Min MOI 1.8 * 10^4 mm4 about X axis (Less stiffness for Pedestrian crash)

Draft Analysis

Draft analysis done to find the undercuts in a panel. This the most important study for manufacturing feasibility of the panel. Here the green zone represents the draft angle is more than 7 degree.

• Check for Draw direction as vertical to vehicle
• Draft angle 7deg

Conclusion

Thus Hood design is completed with all the necessary design considerations.