Design of backdoor

AUTOMOTIVE BACK DOOR DESIGN USING NX CAD

OBJETIVE :

i) From the given styling surface, develop a back door using appropriate design methodologies.

ii) The objective of this project is to design a BIW Back Door of a car with an Inner Panel, Outer Panel, and Reinforcements for the Hinges, Gas stay, Wiper Motor, and Latch by following the engineering standards.

iii) The Inner Panel must be subjected to Draft Analysis for verifying whether it satisfies the Deep Drawing requirements for the tooling direction created in the design.

SOFTWARE USED

NX CAD

INTERDUCION

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 metal design. The backdoor has a lot of components inside and is designed to incorporate them easily. It affects the rear visibility and luggage area.

The material used for door manufacturing depends on the budget and performance of the vehicle. Mostly Aluminium and Steel will be used whereas low-budget vehicles use Steel which makes the manufacturing process easy and cost-efficient since it follows the Stamping of Moulds.

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.

BACK DOOR INNER PANEL

BACK DOOR OUTER PANNEL

IN this back door outer panel divided into two parts

1 outer pannel upper

2 outer pannel lower

outer pannel uppper

this outer panel upper is developed by the styling team by using this outer panel upper to create inner panel and perform heaming on edges on the outer panel thickness of outer panel upper is 0.75 mm

OUTER PANEL LOWER

it is an outer panel lower thickness of the outer panel is 0.75mm and it is also developed by the stlying team for the joining of the inner panel and outer panel develop heaming on the outer panel

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 BACK DOOR OUTER PANEL

DESIGN OF BACK DOOR OUTER PANEL It comes from the styling team u need to check the surface and the surface will well start design process in the face of a problem in thickening the surface so that I rework on the class surface at fillet areas the minimum thickness of outer panel is 0.75

and perform heaming to join the inner and outter panel

DESIGN OF BACK DOOR INNER PANEL

by developing inner panel using the surface from the outer panel and then create a tooling axis it helps to the proper deep drawing process

Create where we will first develop an effective sealing flange by checking all the boundaries and by following the shape of the inner panel design. By creating multiple flanges and by using surface modeling techniques the concept design of the inner panel was created.

• After the concept of the inner panel is developed, then the child components like a hinge, latch, gas-stay locations, and their reinforcements must be designed. Which completes the overall design of the tailgate.

• The embosses were created in ‘V-Shape or Y-Shape’ so that if the vehicle undergoes the crash then the force dissipates over it which reduces the damage transferred to the trunk space.

MASTIC SELLING POINTS

The mastic sealant is used to fix the inner panel with the outer panel which increases the NVH factor and stiffness of the back door.

to maintain the gap in bitween outer and panel 5mm at mastic area

HING EMBOSE

hing embose is used for assembly the hing it helps to door open and close circler holes on hing embose is used to hing clamping with fastners the surface of hing embose is flat

GAS STYA EMBOSE

gas stay embose is used for mount gas stay it helps to hold the weight of back door while the back door open it supports the door

WIPER MOTOR EMBOSE

wiper motor embose is used to mount the wiper motor. wiper motor is used to clean the glass is present on back door and wiper motor embose surface is flat it helping to mount the wiper motor properly

STRIKER EMBOSE

striker embose is used to mount the striker the surface of the striker embose is flat the process of creating creat a circle and the circle is coincide the hinge axis and draws a line and the end point of the line is tangent to circle

HEAMMING

hemming is a process of joining objects in this hemming is used to join the inner and outer panels to maintain a distance between the outer panel and the inner panel is 0.2 mm on that 0.2mm gap add some glue like silicon or some other material to prevent NVH

CORNER RELIEF AREAS

to maintain relief to avoid the shearing in corners while rolling the sheet corners

DESIGNING THE REINFORCEMENTS ON :

1. HINGE REINFORCEMENT

2. GAS STAY REINFORCEMENT

3. WIPER MOTOR REINFORCEMENT

4. LATCH REINFORCEMENT

1. HINGE REINFORCEMENT

Hinges enable the opening and closing of the back door. One end of the hinge is fixed on the backdoor and the other end on the Roof, on both sides. Hinges can be placed outside or inside the backdoor.

The hinge reinforcements are added to compensate for the weak region due to the acting load over it.

2 GAS STAY REINFORCEMENT

Gas Stay is a device used for supporting the back door in its open position. Gas stay requires no manpower and is engaged into support position automatically as the back door opens. One end of the Gas Stay is fixed on the backdoor and the other end on the Body Side or on the Back door stationary area.

Embossing is provided at the Gas Stay mounting area to compensate for weakness and improve strength.

3 WIPER MOTOR REINFORCEMENT

Wiper motor reinforcement is created to mount the wiper motor assembly.

2 LATCH REINFORCEMENT

The Latch & Striker forms the locking mechanism of the backdoor with the car. Due to regular opening, closing, and over slamming of the backdoor, there is stress developed in the Latch and Striker area. To compensate for the same, reinforcements are added in this area.

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.

CONCLUSTION :

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