Challenge

Design of backdoor

DDinesh Kumar10 Feb 2023

DESIGN OF BACKDOOR

Aim:

Using the provided styling surface to come up with a back door design, usinng appropriate design methodologies, and provided the necessary reinforcements and embosses

Backdoor:

What is backdoor of a car?

Backdoor are one of the type of door of the vehicle which are located next to the passanger seat which provides access to the luggage compartment. The backdoor gives access to the luggage compartment to store something while travel.

Other names for backdoor:

Trunk (North american english)
Boot (British english)
Tailgate
Reargate

Type of backdoor(or)reardoor(or)trunk(or)Boot

1.Top mounted

2.Side mounted doors

3.Bottom type

1.Top mounted backdoor:

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.

2.Side mounted backdoor:

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.

These doors are more convenient for the goods handlers for long pipe and lengthy components where one door is kept open. These doors also save accidental head impacts. It is a lot easier to load and unload items in the side-mounted doors.

3.Bottom mounted door:

This bottom type or split type backdoor system are used in the car type such as estate type car, pickup trucks and some luxury SUVs.

These are the most convenient type of back door in which the bottom split is used as a support or even as a table for the tour going people.

Working mechanism:

Gas stays type:

Gas stay types backdoor/liftgate/tailgate 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.

Powered lift system:

Power trunk lid system is another sophisticated way of trunk/liftgate opening mechanism which is to automatically open and close of the trunk/liftgate and release of the latch by the touch of a button.

MANUFACTURING METHODS:

Recently, there have been two approaches to reducing automobile weight. One is by using material lighter than steel and the other is by redesigning the steel structure. Although the former seems very effective, it is very expensive so that it may only be used for an expensive automobile. Therefore, the automobile industry is trying to use steel, which is not costly and recyclable. Lightweight steel can be achieved by improving the performance of the structure or adopting new manufacturing techniques. One of the efforts is the ultra-light steel auto body concept.

Tailor welded blank:

A tailor-welded blank is a blank that is comprised of two separate pieces of sheet metal that have been welded together prior to stamping. Tailor welded blanks allow the welding of the different grades, different thickness or different corrosion coatings together in order to give the properties needed in different areas, without increasing the number of tools needed to form the part and eliminating the fit ability concerns. They also allow a high degree of flexibility in designing parts and large blanks can be formed from much smaller sheets. The use of tailor-welded blanks would reduce the weight of the car.

Backdoor assembly:

The backdoor assembly has the following components,

Outer panel
Inner panel
Hinge reinforcement(LH)
Hinge reinforcement(RH)
Gas stay reinforcement(LH)
Gas stay reinforcement(RH)
Wiper motor reinforcement
Latch reinforcement

Outer panel of backdoor:

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 wiper motor.

Inner panel of backdoor:

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. The possible method is the integration method.

In the integration method, the part is stamped out of a single blank. This reduces the number of tools needed; the assembly cost and eliminates any fit ability problem.

Reinforcement of the backdoor:

The reinforcement provided are hinge reinforcement, gas stay reinforcement, wiper motor reinforcement and latch reinforcement.The reinforcement are basically having1.2 to 1.5mm thickness. The inner and outer panel having 0.75mm thickness.

Hinge reinforcement(LH)

Hinge reinforcement(RH)

Gas stay reinforcement(LH)

Gas stay reinforcement(RH)

Wiper motor reinforcement

Latch reinforcement

Hemming:

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.

Draft analysis:

The Draft Analysis allows the user to easily analyze a part for proper draft angle. A Draft Angle describes the amount of taper for molded or cast parts perpendicular to the parting line. Find the Draft Analysis in Tools tab. Draft Analysis is applicable for 3D part models.

Here we can easily analyze the sheet metals using the proper draft angle.Using this analysis I analyze the inner,outer panel, hinge, gas stay, wiper motor and latch reinforcement by using the tooling direction.

Outer panel