Design of backdoor

Aim: - To use the provided styling surface to come up with a back door design, use appropriate design methodologies, and provide the necessary reinforcements and embosses.

Theory: - The back door is the rear entry gate of the vehicle which gives us the access to the boot space of the car.           

It consists of the 5 components:-

1. Outer Panel
   • Upper Panel
   • Lower Panel
2. Inner sealing flange
3. Hinge & Striker Hook Assembly
4. Gas Stay
5. Reinforcements
   • Hinge Reinforcement
   • Gas Stay Reinforcement
   • Wiper Motor Reinforcement
   • Striker Hook Reinforcement

 DESIGN REQUIREMENTS:-

1. It should not hinder the rear visibility
2. It should not interfere with the boot space
3. It should withstand the rear crash test regulations & requirements
   • Torsion Test
   • Bending Test
   • Abuse Test
   • Dent Test
   • Endurance Test
   • Assembly Load Test
4. The outer & inner panels should be joinned with hemming process as it is a asthetic part
5. The location of hinges & striker should follow the latch trajectory
6. The position of the gas stay should be as per standards

Procedure:-

The backdoor is prepared by assembling the various sub elements such as outer panel,inner panel, reinforcements etc.

The embosses are given to provide the stength to the panels to with stand the force during collision.

The reinforcements are give to the area where some parts need to be assembled such as stiker hook, hinge, gas stay & wiper motor.

To assemble them we use spot welding in the area which is not visible & use hemming process in the area which is visible. 

The corner relives are given to avoid stess concentration in the corner of the hemming flange.

Back Door Outer Upper Panel

Back Door Outer Lower Panel

Back Door Inner Panel

Hinge Reinforcement

Gas Stay Reinforcement

Wiper Motor Reiforcement

Striker Hook Reinforcement

Corner Reliefs

DRAFT ANALYSIS:- The draft analysis is done to check that the part should have a positive draft as the negetive draft part can't be produced.

To do the draft analysis we need to identify the tooling direction, then do the draft analysis according to that axis. The draft angle for the sheet metal parts should be more than 7 degrees.

Negative Draft:- As shown in the image bellow this area have a negative draft so it will have a different tooling axis as it can't be produced with the same tooling axis as whole part.

Conclusion:- The back door was prepared according to the standard design cosideration succesfully.

Fornt View

Side View

Rear View