Design of backdoor

Objective

To create the back door inner panel, outer styling panel with Hemming and reinforcement using NX software with the help of the styling surface provided.

Introduction

Back door of the car is also known as Tailgate. This is a critical part for back impacts occur on the accidents, which should be ensure that crash wouldn’t injured the passengers. Back door consists of one inner panel and two outer panel. Most of the time the back doors are made from steel or aluminum based on the budget of the car the material is selected. In case of the aluminum the strength of the back door would be stronger therefore reinforcement are not required indeed which will reduce overall weight of the part. But aluminum a bit expensive than steel.

All high-end cars use the aluminum panel with more strength and lesser weight.

In inner panel consists of hinge reinforcement, Gas stay reinforcement, Latch and Striker reinforcement and wiper Motor reinforcement.

Reinforcement

It is an extra part given to the module for improving the strength/compensate the loss locally. These parts could be made from outer body scraps. Thickness could usually vary from 1~1.5mm.

figure 1 Reinforcement

Criteria for designing the Tailgate

• Rear Visibility Criteria
• Luggage area
• Hinge And Gas stay reinforcement
• Latch and Striker reinforcement
• Thickness for panel vary from 0.65~0.75.

figure 2 Inner panel

Inner Panel

In above figure on the left larger hole is used to mount the latch and striker actuator, there are the mounting points given for it. In middle there is space for the wiper motor assembly to be place and on the right there is hole is given as a symmetrical design and weight reduction. Thickness of the inner panel is 0.70mm. Rear visibility is maintained as per the styling panel.

Hinges

figure 3 HINGES

Hinges regions are emboss on the component. This would improve the strength around the area. On top two hinges for the back door to mount to the body and one in either sides for gas stay mounting points.

Outer Upper Panel

Figure 5 Outer upper Hemming Panel

Based on the styling panel the outer upper panel was designed. Giving it to wrap on by hemming around the inner panel to protect as well as it is outer most part to avoid the joints hemming is used.

Outer Lower Panel

Figure 6 Outer Lower Hemming Panel

It is lower panel for the outer panel, it is the second component in the outer panel. Even it is hemmed to the inner panel which doesn’t have any other joint method other than hemming. Thickness is 0.70mm for the outer panel.

Assembly

Figure 7 Assembled Back Door

Inner panel and two outer panel are hemmed together. Both inner panel and outer panel are of same thickness which is 0.75mm.

Conclusion

Here the back door is designed as per the requirement and maintaining the passenger safety and security while designing. All parts are geometrically aligned well.