Back Door Project

DESIGN OF BACKDOOR

AIM:

To design a backdoor of the car outer upper, outer lower and inner pannel with the necessary reinforcements by following the master section with the design parameter for the class A surface..

INTRODUCTION:

Backdoor is rear part of the vehicle, it also provides safety from rear part. Backdoor are one of the type of door of vehicle which is located next of the passenger seat , which provides access to the liggage comparment, in most of the cars it operates with help of gas stay. Some luxury cars have powered back door which in turn is driven by an electrivc motor.

Design Considerations In Back Door Design:

The following are the Design considerations taken while designing the Back Door. They are,

• Visibility Criteria.
• Force Dissipation.
• Latch and Stricker Positions.
• Hinge Position.
• Gas Stay Position.
• Hemming and Relief Areas.

All these design considerations go hand in hand with eachother because these positions are dependant on each other and if position gets altered all the positions has to be altered for effective opening and closing of the back door. The Latch and Stricker, Hinge Position and the Gas stay Positions has to be maintained in a proper way so that they play a major role in the opening and closing as well as the rear Visibility criteria of the car.

BACKDOOR ASSEMPLY:

• Inner panel
• outer panel
• hinge and its reinforcement
• wiper motor reinforcement
• latch & stricker and its reinforcement

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 pannel extracted from a styling surface. The pannel is altered for the required design with the surface tools of NX CAD. The thickness provided for the outer pannel 0.75 mm. Hemming is provided with the help of corner relif.

Outer Lower Panel:

The outer pannel extracted from a styling surface. The pannel is altered for the required design with the surface tools of NX CAD. The thickness provided for the outer pannel 0.75 mm. Hemming is provided with the help of corner relif.

INNER PANNEL:

Functional Requirement of Hinge Mounting and Gas Stay Mountings, Wiper Motor Mounting Design should be such that it will provide maximum space for luggage, housing for back light, wiper motor, striker, hinge assemblies and necessary arrangement for gas stay.

Mastic Sealant:

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.

Gas Stay:

Gas stay types are backdoor, lifgate and tailgate is an ideal and most commenly used tailgate machanism from lower segment car to luxury car segment. The idealy components of tailgate consist of a hinge ,door,gas stay and some runbber beadings for sealing fo door.

Latch and Striker:

The Latch and Striker were designed by creating a trajectory that follows the opening and closing of the back door with respect to the hinge axis.

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 pannel the hemming was created by offsetting the surface with the help of face blend and swept surface. The two separate outer panel will be joined using blanking.

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.

Materials commonly used in the metal embossing process include:

• Aluminum alloys
• Steel alloys
• Zinc
• Copper
• Galvanized steel
• Brass
• Cold rolled steel

CONCLUSION:

Thus the Body In White Back Door of a car has been designed following the engineering standards by using NX CAD and also the deep drawing requirements were satisfied.