Design of backdoor

INTRODUCTION:-

The Back Door of a car is the rearmost part of the vehicle which gives access to the trunk space of the vehicle. The rear door also supports the reinforcements and added weights of the Wiper Motor, Gas Stay, Tail Lamp, and Latch and Striker.

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

TAILGATE OR BACK DOOR:

A tailgate is a door at the back of a truck or car, that is hinged at the bottom so that it opens downwards.

Major Parts and Reinforcements:

The backdoor consists of the following basic components:

1. Backdoor Outer Panel (Upper)

2. Backdoor Outer Panel (Lower)

3. Backdoor Inner Panel

4. Hinge Reinforcements (LH & RH)

5. Gas-Stay Reinforcements (LH & RH)

6. Latch and Striker Reinforcement

7. Wiper motor Reinforcement

DESIGN INTENT

The intent of the project is to design a Body In White Back Door of the vehicle considering the engineering standards and manufacturing requirements which satisfies the Deep Drawing Process.

DESIGN CONSIDERATION OF A BACKDOOR:

• Functional Requirement of Hinge and gas stay

• Rear visibility criteria

• Luggage volume

• Crash Analysis

• Bend Test, Dent Test, Torsion Test & Endurance Test

• Rear Crash Regulation

• Gap and flushness Requirements

DESIGN OF BACKDOOR OUTER PANEL:

The Outer Panel is the styling surface of the back door. 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 two parts

1. Outer Upper Panel

2. Outer Lower Panel

Outer Upper Panel:

The Outer Upper Panel Extracted from a styling surface. The thickness provided for the outer panel is 0.75 mm. Hemming is provided with the corner relief.

Outer Lower Panel:

Assembly of Outer Upper & Lower Panel

Tooling Direction:

Tooling direction for Deep Drawing purpose. Then the styling surface needs to be checked and analyzed since it might have irregularities.

I fixed it first. Then the back door was designed using the top-down approach.

DESIGN OF BACKDOOR INNER PANEL:

While designing the inner panel the consideration for its design are Thickness, the gap between the outer panel, and embossing.

The nominal thickness of the inner panel is 0.75.

The clearance gap between the inner and outer panel is 0.2mm

Embosses of the inner should follow the force dissipation criteria.

REINFORCEMENTS:

The thickness provided for reinforcements is 1.2mm

1. HINGE REINFORCEMENT

2. GAS STAY REINFORCEMENT

3. WIPER MOTOR REINFORCEMENT

4. LATCH REINFORCEMENT

STRIKER POSITION:

The position of the hinge should be perpendicular to the latch when the latch and striker meets. The circle is drawn from the center of the hinge axis to find the path of the striker and positioned perpendicular to the path.

HEMMING:

Hemming and seaming are two similar metalworking processes in which a sheet metal edge is rolled over onto itself. Hemming is the process in which the edge is rolled flush to itself.

• The outer panel was designed as two separate parts named as outer panel upper and outer panel lower.

• After designing the outer panel the Hemming was created by offsetting the surface with the help of face blend and swept surface.

• The two separate outer panels will be joined using Blanking

CORNER RELIEF:

During the hemming process, when giving the Corner Relief helps to control sheet metal material behavior and to prevent unwanted deformation during unbend operations and also helps to reduce the number of passes in hemming.

DRAFT ANALYSIS:

• The draft analysis will be performed for the tooling direction created at first and checked that the model is suitable for manufacturing.

• Then to get a complete green portion the necessary changes to the draft angle of the embosses were carried out by optimizing the model.

• The Draft Analysis command enables us to detect that the part drafted will be easily removed or not.

• This type of analysis is performed based on color ranges identifying zones on the analyzed element where the deviation from the draft direction at any point, corresponds to specified values.

Assembly Design:

Assembly Section View

CONCLUSION:

Thus the Body In White Back Door of a car was designed following the engineering standards and also the deep drawing requirements were satisfied.