Challenge

Design of backdoor

AAswin J V26 Apr 2023

Design of Backdoor

Backdoor

Back door also called as Tailgate, is the rearmost part of an automobile which gives access to the trunk space of the vehicle. It also supports the reinforcements and added weights of the wiper motor, gas stays, tail lamp, latch and striker.

Design Considerations of Backdoor

Rear Visibility
Boot space & accessibility
Sealing Flange
Support structures like Hinges and Gas stays
Mount for wiper motor, tail lamps and other wiring loops
Rear crash regulations and tests
Joining techniques such as hemming, spot welding, etc,.
Gap and Flush requirements

Components of Backdoor

Upper outer panel
Lower outer panel
Inner panel
Striker reinforcement
Hinge reinforcement
Gas stay reinforcement
Wiper motor reinforcement

Design

Upper & Lower Outer panel

Outer panel is the aesthetic part of the tail gate. It adds more attraction to the automobile. The outer panel also has the provisions for the tail lamp, rear fog lamp and other mountings. Hemming is done to join the Outer panel with the Inner panel.

Inner Panel

The Inner panel of the back door has the mountings for hinges, gas stay, wiper motor and striker. The Inner panel is the strengthening element of the back door. Flanges like connecting flange, sealing flange and the inner panel flange are present in the inner panel.

Hinge reinforcement

Hinges plays a major role in any door. It is used in opening and closing of door. Here, one end of the hinge is connected to the body frame or the roof of the car, while the other end is fixed to the Inner panel of the back door. Reinforcement is given to compensate the load acting on the region.

Gas stay reinforcement

Gas stay in a tail gate is used to hold open and close the tail gate. It eliminates the manpower by holding the back door open in position. One end of the gas stay is fixed on the body side and the other on the door. To add strength to this region reinforcement is given.

Wiper motor reinforcement

Wiper motor is placed in the back door area under the glass mounting region. It consists of small motor and modules that actuates the wiper. Adding reinforcement to strengthen the region.

Striker reinforcement

Latch and striker is responsible for locking the back door. Stress will be developed as we frequently open and close the door. So, adding reinforcement will make it stronger.

Manufacturing Processes

Deep drawing

Deep drawing is a sheet metal forming process in which a sheet metal blank is radially drawn into a forming die by the mechanical action of punch. It is thus a shape transformation process with material retention.

Embossing

Embossing is a stamping process for producing raised or sunken design or relief in sheet metal. The process can be made by means of matched male and female roller dies, or by passing sheet or a strip of metal between rolls of the desired pattern, theoretically with no change in metal thickness, or by passing sheet or a strip of metal of the desired pattern.

Hemming

Hemming is a forming operation in which the edges of the sheet are folded or folded over another part in order to achieve a tight fit. Hemming is a process of bending/folding the flange of the outer panel over the inner one. The accuracy of the operation significantly affects the appearance of the car’s outer surfaces and is therefore a critical factor in the final quality of a finished vehicle.

Spot welding

Spot welding is a type of electric resistance welding. When two sheet metals are made into contact with each other and pressure is applied on specific points, heat is generated from the resistance and weld is formed.