Design of backdoor
Aim:
Design a back door of a car by usign class A surface
What is a back door?
A door whichbis located at rear side of the car which give access to the luggage, spare wheel etc.
This door can be operated manually or electri power.
most of luxury door operate by electrically.
Types of back door baced on working position
1-Top mounted
2-side mounted
3-botoom door
images
Gas stay powered:
image
Electric operated:
image
Back door Aseembly:
1-Inner pannel
2-outer panel.
3-hinge and its reinforcement
4-wipermotor reinforcement
5-Lactch &striker and its reinforcement
Different sheet metal process used for manufacturing back door:-
-DEEP DRAWING
The metal deep drawing process is an effecctive method of manufacturing cups, cans And other similar deep drawing products. the deep dawing having tow main categories.
1- First stage deep drawing:-
the blank shape of metal is placed on the die and contact with punch .when the metal speciemen is flat piece of sheet metal used in forming and finish the product.initially the punch moves in downward bdirection.the rim of blank is subjected to pure radial drawing between die and blank metal.the metal become a blend and sliding over die and contact with it bend and slide over radii and strech over punch head.
2-Redrawing:
The cmponents drawn from first stage again it is edrawn 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 the metal forming process for producing raised or sunken designs or relief in sheet materials by means of matched male and female roller dies,therotically with no change in 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 , differnt pttern can be produced on the metal sheet.
material commonly used in the metal embossing process:-
- aluminium allloy
- steel alloy
- zink
- copper
- galvanised steel
- brass
- cold roller steel
Hmming:-
hemming is a foming operation in which the edges of sheet are folded over another part in order to achive a tight fit.
Normally hemming operations are used to connect parts together,to improve the apparance of a part and to reinforc part edges.
there are varius type of hemming operation:-
1-conventional die hemming:
in conventional die hemming,the flange is folded over the entie lenght with a hemming tool.
2-Roll hemming:
in roll hemming,the hemming roller is guided by an indusrtial robot to form the flange.
open hem:-
A open hem has a full feature and a return flange.in open hem angle is equal to 180 dgree.
closed hem::
hems without any inside radius are called as closed hem are not recommende if hem geometry is to paintetd or if the material is to be painted or material used is SST or aluminium.
DESIGN OF BACK DOOR IN NX CAD:-
door parts thickness is given below:-
Given data,
given surface has to be repaired according to the smoothness.after repairing the surfaces,the ddoor is divided intotow parts as door outer panel and door lower panel.
First we need to create the toolong diection for the deep dawing operation.it show that all the operations like embossing done by considering this vector direction and it will help in manufacturing the part.
After that we need to have create the selling flange by offsetting the outer panel to the specific distance.
then we will be creating the back door inner panel flanfe by offsetting the outer surface at a distance considderring the sheet thickness and thickening direction.
Then create the connecting flange to jon the inner panel and sealing flange.
then fow wind shield panel mounting. windshield panel is ceated and joined with sealing flange.
Then to improve the strenght of inner panel and reduced the weight emboss and other cut-out are created.
also latch and striker mounting cut-out are created.
another emboss is created for wiper motor mounting
Another flange us created to reduced the vibration of door by joinning the inner outer pannel with help of mastic.
Now assemble the back door with the vehicle hinges are used to open and close the door.for that to increase the local area strength we have to design the emboss and provide the appripriate reinforcement to withstand the load acting upon it.
for positionning the latch and striker,we have to create a trajectory passing through a midpoint of line/axis of tow hinge mounting holes,
DRAFT ANALYSIS:-
Draft analysis design is done to show that the part can be easilly draw out from the mould.
so the above design has been analysed using the tool on NX CAD with having 8 dgree as the allowance.
CONCLUSION:-
thus the back door design from the given stylling surface and draft analysis is als done on the inner panel to check the manufacturing conditions.