Design of backdoor

Title: Design and Development of Backdoor Design

Objective

Developing a back-door design based on the styling surface with given information and to position the latch reinforcement striker, hinge and wiper mountings.

Introduction

Backdoor is also known as tail gate. Backdoor is also has a swinging or closure commodity. First deciding the hinge axis then the latch & striker point join the trajectory to decide the motion of swinging. Also, at right side doors the sealing flange is also important. Preparing the master in the OY top, bottom, hinge area both sides. Developing the sealing surface, corners since gas stay at top and bottom mounting point and also to develop the sealing flanges w.r.t to styling surface. After develop sealing flange then follow the conditions like rear visibility, luggage area thinner. The backdoor section is better for luggage area and the area cannot make a straight surface because need some strength to the panel for rear crash purpose and maintain the space to accommodate the latch and striker, wiper motor. Luggage area or sealing is contact with rear floor at the bottom, roof at the top and body side or tail gate.

Software Used :

    Siemens NX 12.0 (Unigraphics).

      Nowadays most car manufacturers are trying to use Aluminium instead of steel and they reduce the number of parts and weight of the car drastically.

Major Parts and Reinforcements :

Components of the back door :

   1. Back Door Outer Panel (Upper)

   2. Back Door Outer Panel (Lower)

   3. Back Door Inner Panel

   4. Hinge Reinforcements (LH & RH)

   5. Gas Stay Reinforcements (LH & RH) 

   6. Latch and Striker Reinforcement

   7. Wiper Motor Reinforcement

Backdoor parts consist:

1. Upper outer panel
2. Lower outer panel
3. Inner panel
4. Hinge reinforcement mounting points
5. Gas stay reinforcement mounting points
6. Latch and striker reinforcement mounting point
7. Wiper motor reinforcement mounting point

Outer panel

Outer panel is the styling part of the back door and it is developed in different way of structures to attractive the customers, not only back door but every portion of the car outer panel is designed very fine.

Inner panel

Inner panel is most important part in car to give strengthen by adding some features like embosses, reinforcements etc, to avoid harm to passengers from environmental conditions, accidents, and forces etc.

Hinge reinforcement part

Hinge reinforcements are used to open and close the doors of the car and it also gives strengthen at hinge areas. So that no need of extra reinforcements in inner panel at hinge area.

Gas stay reinforcement

The purpose of gas stay reinforcement is to lift the back door of the car.

Gas stay reinforcement are two types and they are

1. Manual system
2. Power lift system

Manual system

The door is opened manually by man.

Power lift system

The door is opened with the help of sensors (automatically).

 

Difference between aluminium and steel parts

Aluminium	Steel
Parts are casted	Parts are stamped
Reinforcements can be neglected	Reinforcements are necessary
Thickness is varied	It has uniform thickness
Lighter in weight and a smaller number of components	Heavier in weight and a greater number of components

Image Shows Reinforcements

Assembly sequence for steel

1. Hinge reinforcement - RH
2. Hinge reinforcement – LH
3. Wiper motor reinforcement
4. Gas stay reinforcement – RH
5. Gas stay reinforcement - LH
6. BG outer upper panel
7. BG outer lower panel
8. Latch and striker reinforcemen.

1. Assembly sequence for aluminium

   1. Back door inner panel
   2. Back door outer panel
   3. Back door outer upper panel
   4. Back door outer lower panel

 

Load cases – General analysis

Bend test

Torsion test

Abuse test

Debt test

Assembly load cases

Endurance test

 

This are the tests are performed on tailgate after its proto Profuction. CAE team members will test these cases on car back door because of forces or loads at different areas and different ways effected to back door.

 

Design of Back Door Inner Panel :

 

• Inner Panel extracted from a styling surface of a back door.
• The thickness provided for Inner Panel is 0.75 mm.
• The inner panel is designed depending upon the outer panel, primarily the sealing flanges are designed and then the using law extensions are connecting to flanges are designed.
• Then the embosses, cutouts are created and also supports the flanges cutouts.
• Then the connection for the reinforcements are also designed
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Toolong Direction

Back Door Outer Panel (Upper):

• The outer upper panel is extracted from a styling surface of a back door.
• The hemming is provided for the upper panel and the hemming surface provide corner relief.
• The thickness provided for the upper panel is 0.75 mm.
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• Back Door Outer Panel (Lower):

  • The outer lower panel is extracted from a styling surface of a back door.
  • The hemming is provided for the upper panel and the hemming surface provide corner relief.
  • The thickness provided for the lower panel is 0.75 mm.

Design Intent :

 

The project intends to design a Body In the White Back Door of the car considering the engineering standards and manufacturing requirements. It also satisfies the Deep Drawing Process.

Hemming :

• Hemming is a forming operation in which the sheet is folded.
• Hemming is the assembly as a secondary operation after deep drawing and using the trim operation is separate to inner panel small portion cuts the hemming.
• Hemming thickness is 0.75 mm.
• Hemming and seaming are two similar sheet metal processes.
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• Corner Relief:

  Relief helps to control the sheet metal material behaviour and prevent the unwanted portion remove using the trim So I gave two corner reliefs for the back door.

   

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Latch and striker reinforcement mounting point

The Latch and striker reinforcement mounting point is developed with the help of axis from hinge position and it is taken approximately then created emboss at bottom of the panel to mount latch and striker assembly.

Wiper motor reinforcement mounting point

Wiper motor reinforcement mounting point is the purpose of windscreen wiper and it is used to remove rain water, snow, ice, washer fluid etc to visible at backside. A wiper generally consist of a metal arm- one end pivots and other end has rubber blade. The arm is powered by a wiper motor and then the rubber blade swing back and forth over the windscreen or glass.

Hinge reinforcement, Gas stay reinforcement and latch striker reinforcement

Reinforcement assembled to give strengthen and supporting purpose like hinges are used to open and closing the doors, gas stay are used to give support for open door not to close, wiper motor and used to swing wind shield blade with the help of motor and latch and striker are used to close the doors for locking purpose.

Draft analysis

• Draft Analysis shows that ready to manufacturing the part of back door inner panel.
• Draft Analysis is clearance with the tool direction and also easily the mould.
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• In this i noticed there is negetive draft but it said that this part can be manufactured like this. It's not like it cannot be manufactured.

Conclusion:

     The car back door is developed with the help of styling surface and developed essential embosses, reinforcement to give strength to back door. Draft analysis done for inner panel w.r.t to tooling direction.

• In this challenge, I prepared my way to design the Inner Panel, the Outer Panel, Wiper Motor Reinforcement, Hinge Reinforcements, Gas Stay Reinforcements and striker reinforcement and its position.

Sharing Gdrive link. As i attach in below box there is size limit for it 20mb only. My file size is 40mb after compressing 34mb. It is beacause of Inner pannel is 30mb in nx cad size. 

Email me at [email protected] if any problem arises. or in case you cannot open file.

https://drive.google.com/file/d/1J27AgQOJ95gTnaH5SadO8BrrX_-TxYle/view?usp=sharing