Challenge

Design of backdoor

SSuresh Chand Athram11 Nov 2022

DESIGN OF AUTOMOTIVE BACK DOOR

Aim:- To design back door (Back door or Tail gate) lift gate of car from the styling of Class A-surface provided using Nx-cad the Ultimate aim to design constrain the Back door by following by industry standarded Benchmark.

Back Door:-

A Back door is BIW component found in all automotive cars genrally used for opening and closing of the gate so we use luggage boot area is usually used for storing items inside a car . generally the opening and closing of the door is co-odrinate by the Latch and stricker position and Gas stay reinforecment is position that is mounted on the body and back door of the car. these positions play a major role in ensuring smooth opening and closing of the tail gate.

Parts of a Tail-Gate:-(Back door assembly parts)

Outer panel upper
Outer panel Lower
inner panel
Hinge reinforcements
Latch and stricker Reinforcement
wiper motor reinforcement
Gas stay Reinforcements

This all are assembled together it is obtained Back door

Type of Back Doors:-

there are three types of Back door on the position of the hing axis. they are

Top Mounted

Side mounted

Bottom mounting door

the major problem in back door is material selection . mostly in past days steel is used, but it makes a very problem the steel parts have heavy weight , so it reduces the fuel economy, insted of steel presently in high end cars aluminium is used to major objective of aluminium it have less density weight of material and its suitable for complex shapes, and it also gives the thickness locally beacuse it if done cating and it's steel comparsion aluminium material give radius values of deep drawing values is less

so by using of aluminium we can reduced of drastically number of parts and assembly involvement. and it is castly material.

these are the certain tests are done in back door, not only back door component all companonents must pass these test but different components have different test.

Different types of sheetmetal operation are done in 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 the metal embossing process include:

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.

Design of Back door in NX CAD :-

apply lift gate Thickness is given below,

Outer panel - 0.75 mm
inner panel- 0.75 mm
Reinforcement -1.5 mm

Given class - A

Given class-A surface has to be repaired to according to the smoothness . After reparing the surfaces , the door is divided into two parts as Door upper panel & Door lower panel

First step we need to tooling direction for Deep drawing operation. it shows that all the operation like offset , embossing is done by considering this vector direction and it will help in manufacturing the part.

after that we create the sealing flange by offsetting the outer panel to the specific distance then we will create the back door inner panel offsetting the outer surface at a distance considering the sheet thickness and thickenning direction. then create the connecting flange to join the inner panel and sealing flanges. then we create wind shield panel mounting and create and joining the lower panel sealing flange. then to improve the strength of the inner panel and reduce the weight then we created Y type emboss and cut -out are created.

Another emboss is created for wiper motor area mounting

back door inner panel give some vibration so that we apply mastic sealant in Gaps

Gas stay reinforcement :-

Hingreforcement:-

for position of Lacht and striker , we have created a trajectory passing through a midpoint of line and axis of perpendicular line draw to axis of hing mounting holes