Design of Backdoor

AUTOMOTIVE SHEETMETAL BACK DOOR DESIGN USING NX CAD

OBJECTIVE:

Main objective of the project is to create the Back door Sheetmetal design in NX cad, and also designing of inner panel, outer panel, Striker and required some reinforcements.

SOFTWARE USED: NX 12.0

• To Creating the Sheetmetal Back door in NX by using Surface features.
• NX Software is a flexible and powerful integrated solution that helps you deliver the products faster and efficiently.
• NX Cad software is widely used automotive, aerospace, thermal power station and more.

INTRODUCTION:

A Door is a Hinged part which is used for entry and exit of the vehicle. So, back door is the one of the Door of the vehicle which is located at rear side. It is provides access to the luggage compartment. In most of the cars are having backdoor open in upward direction. It is hinged to Roof and a gas stay support fixed at the body side outer for Back door keeping the smooth open/close condition.

Back door is mainly made of steel but nowadays Aluminium is also used to making the back door. When using the Aluminium material, that’s reduce the weight of the vehicle.

DESIGN CONSIDERATION OF BACK DOOR:

• Rear visibility criteria
• Luggage Space
• Crash analysis

BACK DOOR TESTS:

We have to check the back door for long term smooth operation. There are some of test are contacting to the back door test.

1.Bend Test

2.Torsion Test

3.Dent Test

4.Endurance Test

5.Abuse Case

6.Assembly load Case

1.BEND TEST:

In bend test case, we have constraint all the four region and give forces to middle area. When forces released from the back door, it should be return to this original position.

2.TORSION TEST:

In Torsion test, same as to the bend test. But we have to give the forces in bottom area in one force should be upward direction and another one downward direction. When forces released from the back door, it should be return to this original position.

3.DENT TEST:

When fixing the back door in position, tool is push the door and check the back door is coming to this original position or not.

4.ENDURANCE TEST:

Endurance test is workability test, the back door is open particular no of cycle. When end of the cycle how the back door behaves for this test.

5.ABUSE CASE:

In Abuse case, we have to check the overslamming and hanging when back door open condition. Because, some peoples are hanging in back door when open condition.

6.ASSEMBLY LOAD CASE:

When assembling the back door in car how much force given to the body whether body withstanding or not.

DESIGN SPECIFICATION FOR THE AUTOMOTIVE BACK DOOR COMPONENT:

We have only the Styling surfaces for Back door. So, we have to decide the design of the back door.

STYLING SURFACE FOR BACK DOOR:

Styling team only give the Class A surface of the model. We have to develop the model with some design specification.

PARTS OF THE BACK DOOR:

1. Outer Panel
2. Inner Panel
3. Hinge Reinforcement
4. Gas stay Reinforcement
5. Striker
6. Latch and Striker Reinforcement
7. Outer panel

1.OUTER PANEL:

Outer panel is created by help of Styling surface. When designing the outer panel first we have to check the Class A surface having any irregularities and discontinuity. In outer panel we have to do only hemming operation, because we creating everything in inner panel and it is also aesthetic surface of the car.

2.INNER PANEL:

Inner panel is creating with help of Outer panel by offsetting some distance. In inner panel we create the Hinge reinforcement,

1.SEALING FLANGE:

In inner panel most important area is sealing flange which decides how the back door will be mounted on the rear side of the car. It is also prevents the entry of dust and water. Sealing flange length should be minimum 25mm.

2. EMBOSSES AND CUTOUTS:

Embosses are provided to the inner panel for strengthening and also dissipate the forces to outside direction when rear collision happens. When cutouts are used for fixing the wiper motor, latch and striker motor. Then also used for maintain the CENTER OF GRAVITY of the panel. Some of embosses are,

1. Y Embosses
2. Hinge Embosses
3. Gas stay Embosses
4. Latch and Striker Embosses
5. Wiper motor Embosses
6. Plastic Component Embosses

1.Y Embosses:

Y embosses are given to the inner panel for when the rear collision happens force should be Dissipate to outside direction. That’s why we give the Y type embosses.

2. Hinge Embosses:

Hinge embosses are used for when back door is hinged to rear side of the vehicle. When openclose condition lots of forces are acting at hinge area. So, to overcome this problem we have to give the embosses.

3. Gas stay Embosses:

Gas stay embosses are mainly used for when back door condition, we can’t hold the back door long time. So, we have to give the gas stay embosses for withstand weight of the back door.

4. Latch and Striker Embosses:

Latch and Striker embosses are used in back door for when back door openclose time striker is fixed to the latch. So, back door doesn’t open when vehicle moving condition.

5.Wiper motor Embosses:

Wiper motor embosses are used for just hold the wiper motor position.

6.Plastic Component Embosses:

Plastic Component embosses are used for hold the wipers in position.

7. Extension of inner panel:

The inner panel is fixed to outer panel by process of hemming operation. But still there some rattling noise. So, we have to extend the inner panel to fixed to the outer panel. When extend the inner panel minimum distance between extend sheet to outer panel 4-5 mm.

3. REINFORCEMENTS:

In back door design we are using some reinforcements. There are,

1. Hinge Reinforcement
2. Gas Stay Reinforcement
3. Wiper Motor Reinforcement
4. Latch and Striker Reinforcement

1. Hinge Reinforcement:

Hinge reinforcement is used for When creating the embosses so some areas are weakening to overcome this problem we have to the reinforcement.

2. Gas Stay Reinforcement:

Gas stay reinforcement is used to for external support to the gas stay embosses.

3. Wiper Motor Reinforcement:

When creating the embosses so some areas are weakening to overcome this problem. we have to give the reinforcement.

4. Latch and Striker Reinforcement

When creating the embosses so some areas are weakening to overcome this problem. we have to give the reinforcement.

6. Plastic Component Embosses:

Plastic Component embosses are used for hold the wipers in position.

4. HEMMING OPERATION:

In hemming method, we have to join the inner panel and outer panel are joined together by hemming operation. When welding method is spoil the aesthetic look of the vehicle.

Hemming operation is a forming operation in which edges are folded or folded over the another part to achieve tight fit.

1. Conventional die hemming
2. Roll hemming

1. Conventional die hemming:

Conventional die hemming is suitable for mass production. In die hemming, the flange is folded over the entire length with a hemming tool.

2. Roll hemming:

Roll hemming is carried out incrementally with a hemming roller. An industrial robot guides the hemming roller and forms the flange. Roll hemming operation can also be divided into several pre-hemming and final hemming process steps.

5. LATCH TRAJECTORY MOTION:

Latch trajectory is important for back door operation, While the opening and closing the back door in car, latch perfectly aligned with the striker point and also the latch trajectory line is perpendicular to the hinge axis. Then only we have the smooth operation in Back door.

6. DRAFT ANALYSIS:

Draft analysis is to check the inner panel can be deep drawn. The Draft Analysis command enables you to detect if the part you drafted will be easily removed. 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.

Minimum draft angle is 7 degree is considered for analysis. Green colour show positive draft angle of the part more than 7 degree.

7. RELIEF IN SHEETMETAL:

When creating the hemming operation, some corner edges have string Sheetmetal to overcome the issues we have to give some relief that area. When creating the relief in corner area to avoid damages and also smooth edges we get.

BACK DOOR MODEL VIEW:

1. FRONT VIEW:

2.SIDE VIEW:

3. TOP VIEW:

ADDITIONAL VIEWS:

CONCLUSION:

So, we are made it the Back door design. In this project we created the Back door outer panel, inner panel, striker and required embosses, reinforcement. With help of Class A surface we made the required component of the Back door.