Design of backdoor

The trunk (North American English) or boot (British English) of a car is the vehicle's main storage or cargo compartment, often a hatch at the rear of the vehicle. It is also called a tailgate.These doors can be operated manually or electric powered. In most of the luxury cars door is electrically operated. Ii involves a very major role during rear crash cases. so our design must be obey crash requirements. the institute of highway saftey analyse the diffrent  accidents and they set a test to rate our car. so these rating depends uopn the design of the trunk and material used, flenges, embosses, type of joining of inner panel and outer panel etc.

Types of doors based on working position,

1. Top Mounted Door
2. Side mounted Door
3. Bottom Door

Functions of the Backdoor:

• It protects the occupants and luggage from getting damaged.
• It houses assembly of tail lamps, wiper motor and other components.
• It serves as entry and exit point for luggage/passengers.
• It houses windshield glass which helps in rear visibility Parking sensors, rear view camera are mounted on it.

1.electrically operated

2.gas stay powered

the main purpose of these mechanisims is to open the back door without heavy efforts, because the backdoor have different parts and the weight of the back door is high, so we are not able to open the back door manually, so we introduced these two types comodities. and these also decides the premium of the car, mostly the electrically operated used in premium cars.

Back Door Assembly:

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

MANUFACTURING PROCESS 

Conventional tailgate assemblies are made from stamped metal panels welded together to form a tailgate. Latches are added on either side of the tailgate to engage a striker on the pickup sides. A handle operates the latches to open and close the tailgate assembly. Steel tailgate assemblies provide a durable and secure closure for the pickup bed.

Another disadvantage of steel tailgate assemblies is the cost of the tooling required and equipment required to stamp metal tailgate components. Metal tailgate components are generally produced in a large stamping press. The stamping presses generally require finely machined tools made from hardened steel. The cost of tooling a metal tailgate is much more expensive.

PROCEDURE:

1. Checking the Geometry:

• Once the model is opened, we get a Class A Surface of the back door.

2. Tooling axis creation:

• Draw a line from left and right extremities almost parallel to the path of the surface along the unsymmetrical axis.
• Using the Derived lines tool, create a bsecting line as shown below:

7. DRAFT ANALYSIS:

(I) Inner Panel

• Gas stay reinforcement    

Gas stays support the weight of the back door while they are open. More load act on this region ,So suitable  reinforcement provided  for better strength 

it is spot  welded on the inner panel.

• Wiper motor reinforcement  

Reinforcement provided in this region for fixing the wiper motor.

• Latch and striker reinforcement 

The striker is designed to create a tight fit between the door and the seal on the cab. The door open and shut several times in a day.So more force acting on  this area.The reinforcement given in the latch and striker mounting area to increase the strength.it is  spot welded on the inner panel                                                                                     

• trajectory 

The trajectory is created to position the latch and striker .latch system must be able to catch the striker of the door  the while  closing. Circle is drawn from the hinge axis. The striker follow this path.

• Hemming 

Hemming is a technology used by the automotive industry to join inner and outer closure panels together (hoods, doors, tailgates, etc.).In addition adhesive bond provide for excellent joining of panels it also reduce vibration .here this design 0.2mm clearance provided for hem glue .