Design of backdoor

AIM

Use the provided styling surface to come up with a back door design, use appropriate design methodologies, and provide the necessary reinforcements and embosses

INTRODUCTION

BACK DOOR

Back door or tail gate simply refers to the back of the car that can open and close.it covering the rear of the vehicle. It provide access to a cargo area (trunk/boot ).A tailgate hinged at the roof is a predominant characteristic of hatchbacks, estates/station wagons and lift backs .The door or opening of a cargo area may be hinged at the top, side, or bottom.

In most cars, usually this process will be done manually. One has to get down the car to open and close the tail-gate with the car key. Nowadays, automobile manufacturers providing Advanced features like the automated tail-gate. An automatic tail-gate in the car will do the process of shutting and opening the tail-gate electronically.

Types of the back door

Top-Mounted:

This type of back doors is used in a station wagon, pickup truck and some of the sport utility vehicles. Today’s modern cars use top-mounted tailgating systems which are both powered and also gas stay supported. These top mounted tailgates provide greater rear visibility compared to side-mounted or bar doors which have canter pillars in it.

Side Mounted Doors:

As the name signifies side-mounted doors are the one which is used in the van type MPVs, SUVs, pickup truck vehicles. These side-mounted doors or barn doors are a lot easier compared to top-mounted doors. These doors are generally smaller in size and can be easily accessed.

Components to create:

1. Outer Upper Panel.
2. Outer Lower Panel.
3. Inner Panel.
4. Gas Stay Reinforcement LH and RH.
5. Hinge Reinforcement LH and RH.
6. Striker Reinforcement.
7. Wiper Reinforcement.

OUTTER PANEL UPPER AND LOWER:-

Outer panel is the styling surface of the back door. Glass for rear visibility is mounted on the outer panel upper. Rear light is also mounted on the outer panel upper. Number plate is mounted on the outer panel lower. Spot welds and other manufacturing process should do only on the inner panel because the outer panel is styling surface which should not have any scratches or welds. Because it affect the style of the car which leads to bad impression on the customer.

OUTER PANEL UPPER

The thickness provided to the outer panel is 0.75 mm.

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 .

OUTER LOWER PANEL

INNER PANEL:-

Car backdoor inner panel is made of either steel or aluminum. Most of the luxury car's inner panel is made of aluminum because of its properties. But the cost of aluminum is high. Cost of aluminum is more as compared to steel. To easily understand, the cost of aluminum for inner panel is higher than the cost of all parts of backdoor together.

Wiper motor, latch reinforcements, hinge reinforcement and gas stay reinforcement are mounted on the inner panel of the backdoor only. The embosses in the inner panel helps stiffening the inner panel and act as a local reinforcement. Another purpose of giving emboss is to distribute impact forces towards hinges.

The inner panel is produced by either casting or through deep drawn method. Mostly aluminum panel is only casted, steel inner panel is made by deep drawn process only .If it is deep drawn, then there must be a tooling direction through which that direction the panel is Deep Drawn.

Tooling Direction:

• Before starting to design the inner panel of the back door the tooling direction for Deep Drawing purposes should be created.
• Then the styling surface needs to be checked properly and analyzed since it might have irregularities, hence it must be fixed first.

HINGE REINFORCEMENT:-

Hinges support the weight of the whole backdoor .Hence the reinforcement must be provided there too. The emboss is designed in such a way that the hinge should operate freely. The hinge is connected to the rear roof of the car.

GAS STAY REINFORCEMENT:-

Gas stay reinforcement is used to lift the backdoor automatically. There are two types of gas stay one is semi-automated type the back door needs little force to lift after that it lift the backdoor automatically. In fully automated, it has power spindle which lift the back door automatically.

WIPER MOTOR REINFORCEMENT:-

Wiper is used to wipeout the rain water falls on the backdoor window. Its actuated by the motor which is mounted on the inner panel. Due to the vibration and heat created by the motor. The inner panel where the motor is mounted gets deform and parts attached to the motor starts to vibrate which leads to poor NVH.So we have to provide the reinforcement where the wiper motor is placed.

LATCH REINFORCEMENT:-

At bottom of the panel, reinforcement and emboss are given to accommodate the latch and striker assembly. Generally key operated or automatic remotely controllable mechanism is used to keep the door open or closed. The actuators ,receivers and other electronics devices are mounted on the inner panel only.

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.

DRAFT ANALYSIS:

Inner Panel