Design of backdoor

BACKDOOR DESIGN OF CAR

INTRODUCTION:

Backdoor/ tailgate is one of the closure commodities in BIW sheet metal design. The backdoor has lot of components inside and is designed to incorporate them easily. It affects the rear visibility and luggage area.

Objective

1. From the given styling surface, develop a back door using appropriate design methodologies.
2. Provide the necessary reinforcement and emboss definitions.

Components

The backdoor consists of the following basic components:

1. Backdoor inner panel.
2. Backdoor outer panel upper.
3. Back door outer panel lower.
4. Hinge reinforcements.
5. Gas-stay reinforcements.
6. Latch and striker reinforcements.
7. Wiper motor reinforcement.

Major parts

Outer panel

The outer panel is the styling surface of the backdoor, other components of the backdoor are designed with reference to the outer panel. It acts as the outer cover and deals with the aesthetics of the car.

In this design outer panel is divided into 2 parts

Outer upper panel

Outer lower panel

Inner panel

The inner panel provides strength to the backdoor. There many cases where inner panel is subjected to stress due to frequent opening and slamming. These stress and depression factors are compensated by features like embosses and reinforcements.

All other components of the backdoor i.e., reinforcement is accommodated by the backdoor inner panel.

Cut-outs are made in the inner panel for fixing the lighting system and the wiring harness.

Reinforcement

Reinforcement are provided in the design to improve the strength in the area where loads are acting

Hinge reinforcement

Hinges enable the opening and closing of the backdoor.one end of hinge is fixed on the backdoor and the other end on the roof, on both sides. Hinge can be placed outside or inside the backdoor.

Hinge reinforcement are added to components the weak region due to acting load over it.

Gas stay reinforcement

Gas stay is advice used for supporting the back door in its open position. Gas stay requires no man power and is engaged into support position automatically as the back door opens. One end of the gas stay is fixed on the backdoor and the other end on the other side or on the back door stationary area. Embossing is provided at gas stay mounting area to compensate weakness and improve strength.

Latch and striker reinforcement

The latch and striker form the locking mechanism of the backdoor with car. Due to regular opening, closing and over slamming of the backdoor, there is stress development in the latch and striker area. To compensate for the same, reinforcements are added in this area. Position of this reinforcement is determined by the midpoint of axis point, which should be aligned with the latch and striker thought the trajectory of the back door opening and closing.

Wiper motor reinforcement

Wiper motor reinforcement is created to mount the wiper motor assembly.

Mastic sealants

To improve NVH (noise, vibration and harshness) i.e to reduce these levels, mastic sealants are used. They are made of hard rubber and are introduction as a paste thereby joining the inner and outer panel with a thickness of 5mm.

Mastics are preferred over welding to join inner and outer panel as welding reduces the aesthetics of the car from the outer surface.

Final assembly of back door

Draft analysis

Draft analysis is done to analyses the draft angle. This allows us to verify whether the product will be easily removed from the tool.

Conclusion

Back door was designed and developed from the given styling surface with essential reinforcement and emboss definitions. Draft analysis was done on the inner panel.

Note: Due to big size of zip file, unable to create single file of 20mb size. so i shared it has two files, kindly check both.