Challenge

Design of backdoor

YYuvaraj Ummannavar10 Apr 2023

AR BACK DOOR DESIGN

Aim: To design back door of car using given outer class 'A' surface.

A door which is located at the rear side of a car which gives access for the boot space to store luggage, spare wheel etc.

These doors can be operated manually or electric powered. In most of the luxury cars door is electrically operated.

Different types of back door:

Top Mounted Door
Side mounted Door
Bottom Door

Back Door Assembly:

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

Different Sheetmetal processes used for manufacturing the Back Door

Deep Drawing:

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

First- stage drawing: The blank shape of metal is placed on the die and contact with the 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 blank is subjected to pure radial drawing (drawing toward in vertical axes) between die and blank metal. The metal become a bend and sliding over die and also stretched between die and punch. The metal in vicinity of punch head and contact with it bend and slide over radii and stretch over punch head.
Redrawing: The components drawn from first stage again it is redrawn convert into more depth to form a cup shape in the die and punch. The second stage of drawing is called as redrawing.

Embossing:

Embossing is a metal forming process for producing raised or sunken designs or relief in sheet materials by means of matched male and female roller dies, theoretically with no change in metal thickness or by-passing sheet or a strip of metal between rolls of the desired pattern. Metal sheet is 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.

Materials commonly used in embossing process

Aluminum alloys
Steel alloys
Zinc
Copper
Galvanized steel
Brass
Cold rolled steel

Hemming:

Hemming is a forming operation in which the edges of the sheet 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 the appearance of a part and to reinforce part edges.

In car part production, hemming is used in assembly as a secondary operation after deep drawing, trimming and flanging operations to join two sheet metal parts (outer and inner) together. Typical parts for this type of assembly are hoods, doors, trunk 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 a hemming tool.
Roll hemming: In roll hemming, the hemming roller is guided by an industrial robot to form the flange.

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

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

Closed Hem: Hems without any inside radius are called as closed hem. Closed hems are not recommended if the hem geometry is to be painted or if the material used is SST or Aluminium.

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 the metal left behind is considered as a waste.

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.

Design of Back door Using NX CAD:

Door parts thickness is given below,

Outer Panel - 0.75 mm
Inner Panel - 0.75 mm
Reinforcements - 1.5 mm

Given Data,

Given surfaces has to be repaired according to the smoothness. After repairing the surfaces, the door is divided into two parts as Door Outer Upper and Door Lower Panel.

First, we need to create the Tooling direction for the Deep drawing operation. It shows that all the operations like embossing is done by considering this vector direction and it will help in manufacturing the part. After that we have to create Sealing Flange by offsetting the outer panel to the specific distance.

SEALING_FLANGE :

Sealing flange is main portion of back door which is helps to controls the leakages & it helps as supportive system