Design of backdoor

BACKDOOR:

• Back doors are one of the type doors of the vehicle which are located next to the passenger seat, is the section of the car that opens upwards, downwards, or laterally to provide access to the luggage compartment or seating area.
• The backdoor of most cars opens upwards.
• In most of the cars, these back doors are operated with the help of gas stay which in turn reduces the effort required to lift open the door.
• The backdoor of an automobile is primarily made of steel, however recently aluminum is also used to make the panels.
• The fundamental advantage of aluminum over steel is that it has a lower density than steel, which reduces the overall weight of the vehicle.
• However, aluminum is more expensive than steel.

Types of the back door based on working positions:

• The door or opening of a cargo area may be hinged at the top, side. bottom.

1.Top mounted:

2.SIDE MOUNTED:

3.Bottom / split type:

Types based on Working Mechanism:

1. Gas Stays type.
2. Powered Lift system.

1.Gas Stay type:

• Gas Stay type backdoor is an ideal and most commonly used tailgate mechanism from lower segment car to luxury car segment.
• The ideal components of tailgate consist of a hinge, door, gas stay and some rubber beadings for sealing of door.

2.Powered Lift System:

• Power trunk lift system is another sophisticated way of trunk or liftgate opening mechanism which is to automatically open and close of the trunk and release of the latch by the touch of a bottom.
• Powered trunk Lift system consists of a power latch, anti pinch switch, PTG assly, PTG main switch.
• When the switch is pressed in the compartment or outside the power latch releases the latch and the entire backdoor is opened.

BACK DOOR ASSEMBLY:

The back door assembly of a hatchback or SUVs has the following components

1. Inner panel
2. Outer panel
3. Hinge reinforcement
4. Gas stay reinforcement
5. Wiper motor reinforcement
6. Latch/striker reinforcement

1.INNER PANEL:

• The inner door panel is a component which is used for strengthening the door assembly and it is one of the most important components on which all accessories are mounted like hinges, glass guide channel moulded trim latch etc.

2.Outer panel:

• The outer panel of the back door is similar to other BIW components where it is the aesthetic part of a vehicle.
• The coating provided is of multi-stage which has the property of scratch resistance, rust prevention and smooth and attractive finishes.
• The outer panel also has the provisions for the tail lamp, rear fog lamp and also has the provision for licence plate mountings.
• Most of the hatchback cars have the provision for wipermotor.

3.REINFORCEMENT:

• The reinforcement provided is of 4 numbers which consist of hinge reinforcement gas stay reinforcement, wiper motor reinforcement and latch/striker reinforcement.

4.HEMMING OPERATION:

• Hemming is a mechanical joint design which is used for joining inner and outer closure panels as found indoors, hoods, bonnets and lift gates.
• To increase crash resistance the gap between the hemmed panels is filled with a high-strength adhesive which also prevents from corrosion.

5.Hemming relief:

• Hemming reliefs are cut-outs which are provided on the hemmed corner of the panel assembly which in turn to avoid some of the hemming defects such as wave-like OR wrinkle formed surface

6.Latch/striker rotation angle:

• This rotation angle of the line denotes the line of action of backdoor when hinged to the body of the car.

Draft Analysis: