Design of backdoor

Back door design

objective

ude the provided styling surface to come up with a back door design,use appropriate design methodligies and provide the necessary reinforcements and embosses

software used

nx cad

backoor introduction

an automobile back door or taligate is the panel that covers the door of an automobile .it enables access to the main luggage compartment .a hinge allows the boot lid to be raised ,while devices such as springs or gas cylinders hold it up in the open position the backdoor is an assembly of many parts such as inner panel ,outer panel upper ,outer panel lower and reinforcement .inner panel is attached to the outer panel using mastic sealant.

total no.of parts in backdoor are ;

1. back door outer panel(upper)
2. backoor outer panel (lower)
3. back door inner panel
4. hinge reinforcement
5. gas stay reinforcement
6. latch and striker reinforcement
7. wiper motor reinforcement

hemming

hood outer panel and inner panel are joined to gether using hemming process.in this process outer panel is wrapped around inner panel from all the sides to restrict its movement.this is done using rollers.

final hemming

• first outer panel is offset by a distance keeping the thickness and direction in mind
• the sheet is trimed so as to get a flange of 15 mm width
• then a bride curve is made between outer panel and the hemming flange .this curve will act as primary curve for us
• Then multiple swept surfaces are created to get them like surfaces
• everything is sewed together to get a single outer panel

Tooling direction

• Before starting the inner panel of the back door the tooling direction for deep drawing purpose should be created
• then the styling surface needs to be checked properly and analyzed since it might have irregularites .hence it must be fixed first
• the back door was designed using a top-down approach

desgin of back door inner panel

• The inner panel extracted from a given styling surface
• The panel was modified fir the require design with the surface tools of nx cad
• The thickness provided to the outer panel is 0.75

Corner relief

during the hemming process,when given coner relief helps to control sheet metal material behaviour $ to prevent unwanted deformation during unbend operations &also helps to minimize the number of passes in hemming .

designing the reinfocement

the thickness provided for all reinforcement is 0.75

• hinge reinforcement
• gas stay reinforcement
• wiper motor reinforcement
• latch reinforcement

hinges allow the opening and closing of the back door.one end of the hinge is fixed on the back door and the other end on the roof .hinges can be placed outside or inside the back door .the hinge reinforcement are added to compensate for weak region due to the acting load over it.

draft analysis

• the draft analysis was performed for the tooling direction created at first and checked that the model is suitable for manufaturing .
• Then to get a compelte green portion the required changes to the draft angles of the embosses were carried out by optimizing the model .
• The draft analysis command is used to defect that the part drafted will be easily removed dor not .
• This type of draft analysis is performed based on color ranges
• The identifying zones on the analyzedd element where the deviation from the draft direction at any point corresponds to specified values.

conclusion

Thus the back door was designed from the given styling surfaces and draft analysis is also done on the inner panel to check the manufaturing conditions .in this challenges i learned to design the inner panel ,ouer panel ,wiper motor reinforcement ,hinge reinforcement,gas stay reinforcement,latch and striker reinforcement and its position .