Design of backdoor

BACK DOOR DESIGN

OBJECTIVE:

To develop backdoor of car by using given styling surface and provide necessary embosses and reinforcement to the backdoor

INTRODUCTION:

Backdoor of the car is also known as tailgate. This is critical part for back impacts occur on the accidents, which should be ensured that crash wouldn’t injured the passengers. Backdoor consist of one inner panel and two outer panel most of the time.

The backdoors are made from steel aluminium based on budget of the car the material s selected.

In case of aluminium the strength of backdoor would be stronger therefor the reinforcement are not required indeed which reduces the overall weight of the part. But aluminium is bit expensive than steel.

Types of Doors based on working position,

1.Top mounted Door

2. Side mounted Door

3.Bottom Door

Backdoor Assembly consist of following parts:

1 Inner Panel

2.Outer Panel

2, a)Outer Panel Upper

2, b) Outer Panel Lower

3. Hinges and reinforcement:

4 Wiper motor Reinforcement,

5 Latch and Striker reinforcement

6 Gas stay reinfoercment

Assembly of back door:

The major problem in backdoor is material selection. Mostly in pst days steel is used but makes a very problems the steel parts have heavy weight, so it educes the fuel aconomy instead of steel presently in high end cars aluminium used.

The main objective of aluminium it have less denser material it hve suitable for complex shape

Different types of Sheet metal operations are done in Back door

• Deep Drawing:

The motel deep drawing process is an effective method of manufacturing of cups, cans and other similar deep drawing products. The deep drawing having two main categories.

First stage drawing: The blank shape metal placed on the die and contact with punch. When the metal specimen is flat piece of sheet metal

Used in forming and finish the product. Initially the punch moves in downward direction the outer rim of ram subjected to radial drawing.

(Drawing towards the vertical axes) between die and blank metal. The metal becomes bend and sliding over die and also stretched between die and punch. The metal vicinity of the punch head and contact with bend and sde over radi and stretch over punch head

Redrawing: The components drawn from first stage again it redrawn convert into more depth to form a cup shape in the die and punch. The second stage of drawing is called redrawing.

• Embossing:

Embossing is a metal forming process for producing raised or sunken designs or relief in sheet material by means of matched male or female roller. Dies theoretically with no change in metal thickness by passing sheet metal or a strip of metal between rolls of the desired pattern. Metal sheet id drawn through the male and female roller dies producing a pattern or design on the metal sheet. Depending on the roller dies used different patterns can be produced on the metal sheet.

Material commonly used in metal embossing process:

• Aluminium Alloys
• Steel Alloys
• Zinc
• Copper
• Galvanized steel
• Brass
• Cold rolled steel

3. Hemming

Hemming is a forming operation in which the edges of sheets are folded or folded over another part in order to achieve a tight fit. Normally hemming operations are used to connect parts together to improve appearance of a part and to reinforce part edges.

In car production hemming is used in assembly as secondary operation after deep drawing trimming and flanging operations to join to shet metal parts (outer and inner) together. Typical parts for this type of assembly are hood, door, trucks lids and fenders.

There are various types of hemming operations.

Conventional die hemming: In conventional die hemming the flange is folded over the entire length with hemming tool

Roll Hemming: In roll hemming, hemming roller is guided by an industrial robot to form the flange.

Open Hem: A hem has a full round feature and return flange. In open hem bend angle is equal to 180 degrees.

Tear drop Hem: In tear drop hem he bend angle is greater than 180 degrees.

Closed Hem: Hem without any inside radius are called as closed hem. Closed hem are not recommended if the hem geometry is to be painted or if the materil is used ssd or aluminium.

4. Blanking:

Blanking is a cutting operation of a flat metal sheet and the article punched out is known as blank. Blank is the required product of the operation and metal left behind os considered as a waste.

5. Punching:

It is similar to blanking only the main difference is that, the hole is the required product and the material punched out from the hole is considered as a waste

Inputs for designing backdoor;

Outer panel: 0.75 mm

Inner panel : 0.75 mm

Reinforcements-1.5 mm

Draft Analysis of back door :

CONCLUTION:

The backdoor outer and inner panel were designed with the help of the styling surface along the tooling direction and the draft analysis was performed on the inner panel and all the reinforcements were designed and placed at appropriate positions.