Design of backdoor

AIM:

To Design the Back Door of a car from the Styling surface and use appropriate design methodologies and provide the necessary reinforcements and embosses.

BACK DOOR:

Back Door is a Automotive component of a car to cover the rear side of the vehicle and it is also called Tailgate.It is the most important component during the rear crash and it should absorb the rear impact without impacting the passengers.

• It provides a cover from external particles to the inner cabin of a car and also to cover the rear side of the cabin.
• Back Door mainly consists of an Inner panel,Outer panel while the Outer panel can be single or Multiple components.
• The Outer panel consists of Tail lights(3), Rear windshield(4), windshield wiper(1) and Number plate mount(2).

• The Inner panel consists of Wiper motor mount,reinforcements, gas stay and hinge mounts and reinforcements.

MATERIALS:

Car Door is mainly made from Steel or Aluminium based on the budget.Aluminium improves the strength of the component and also reduces the weight of the component.

These components are created by the stamping process with a constant thickness of 0.6-0.8mm.

Gas Stay:

Gas Stays are the components which are used to stay in hold of a component.

In car backdoor,these are used to hold the trunk lid/tailgate during opening without any hand power or stopper to hold.

Gas stays are used based on the budget.

Hinges:

Hinges are used to open and close operation of the tailgate/trunk lid.

Reinforcements are provided for both Hinges and Gas stays to the inner panel to hold strong and to increase strength.

Hemming:

Hemming is a sheet metal forming process in which sheets are joined by bending it usually to 180°.

LOAD CASES:

Load cases are conducted on the back door to check the strength of the component in various cases.

METHODOLOGY:

1.Create the Inner panel with embossments to the Hinges,Gas stays,Latch portion,Wiper mount based on the Outer panel by giving the clearance.

2.Create the Hemming to the Outer panel to seal the Inner panel and provide the corner reliefs.

Provide the clearance of 0.2mm between the outer and inner panel.

Back door/Tailgate consists of

1. Outer panel (thickness=0.75mm)
2. Inner panel (thickness=0.75mm)
3. Hinge reinforcement (thickness=1mm)
4. Gas stay reinforcements (thickness=1mm)
5. Wiper mount (thickness=1mm)
6. Latch portion

3.Line Trajectory is the operation which is used to close and open the trunk lid.

Procedure:

1.Check for any Sharp edges/curves in the Outer Upper Panel in the given Class A surface.

2.Extract the surface of Class A and then remove those edges/curves by Split and join those surfaces using the Blend option.

3.Now create the Tooling direction for the Backdoor for Manufacturing the part using Deep Drawing.

4.Now offset the Outer panels(upper & lower) to a distance of 1.7mm (considering the thickness of panels) towards bottom side for inner flange and to a specified distance to create Sealing flange.

5.Now using the Spline option create the connecting flange/surface that connects Upper and Lower panel which means to connect inner panel flange and sealing flange.

6.To increase the strength of the backdoor and decrease the weight of it we use ‘Y’ type embosses and also other cutouts are created to reduce the weight.

7.Holding mounts are also created to hold the Outer Panel with the Inner panel using the Mastic sealants.

8.Create the mounting points for Hinges,Gas stay,Wiper.Hinges are used to open and close the backdoor and Gas stays are used to hold the door in open.

9.Now to strengthen the mounting points of Hinge,Gas stay and Wiper, reinforcements are created with greater thickness than the inner panel.

10.In order to lock the backdoor, Latch and Stiker are created at the bottom center of the door.Reinforcement is also created to strengthen the Latch part.

11.Now create a Trajectory of a circle for positioning the Ltch and Stiker by creating points on both sides of the Hinges and using the two points to create a line.

12.Create a midpoint between the two points of hinges by taking the line as a support.Now using the midpoint create the trajectory where the circle should pass through the center of the striker.

13.On the Outer Panels Hemming is done to join the Outer(inner side) and Inner panel(outer side) with a clearance gap of 0.2mm.

14.Corner reliefs are given to the outer panel.

15.Generate the Draft analysis on the components Latch portion, Outer panel and Inner panel.

Result:

Developed the Backdoor of a car with the necessary panel, reinforcements, embosses.