Design of backdoor
DESIGN OF BACK DOOR
Objective
Design a back door outer panel, back door inner panel and its reinforcement by using provided styling surface.
Introduction
A door is a hinged part which is used to enter and exit in the vehicle. Here we designed a back door which is placed in the rear side of the car. It is also called as tailgate. It helps to access the luggage compartment. Back door has lots of component which inclued Back door outer upper panel, Back door outer lower panel, Back door inner panel, Hing reinforcement, Gas stay reinforcement, Wiper motor reinforcement and Latch and striker reinforcment.
Back Door Assembly
Back door outer panel
The Outer panel of the back door is divided into two parts which is back door outer upper panel and back door outer lower panel which is shown in the above fig. back door outer panels are the aesthetic elements of a car. This part of the back door will be designed by styling team. From this part we can able to design a back door inner panel. There will be hemming flange which is used to attach the back door outer panel and the inner panel. Hemming relifs must be given to every corner in the back door outer panel. It helps to do hemming operation.
Back door inner panel
Back door inner panel design is show in above fig. It is designed from the back door outer panel. It is the part that gives strength and rigidity to the outer panel. Here we created proper emboos to strengthen the back door and also we provided proper space for mastic sealent which stick outer panel and the inner panel and also absorb noise and vibration. And also there will be a seperate emboss for latch and striker, and as well as hinge and gas stay.
Latch Trajectory
Latch and striker is the part that helps to catch and lock the hood when ever we needed and also we can unlock. We should place latch and striker properly. To place the latch proper position we must fix the hinge first, Here we take a centre point as a hinge axis . Then we place the Latch acording to the hinge axis. Always The centre of the striker's circular trajectory should be perpendicular to the hinge axis. Here we place the latch acording to its trajectory shown in the fig.
Draft analysis of inner panel
Here we designed all the flanges and the emboss by considering tooling direction during manufacturing processes.
Reinforcement
We must incresses the strength of the area where we mount hinge, Wiper motor, Gas stay and the latch. Here we provide proper reinforcement for the mounting area to increase the strength.
Manufacturing processes
1. Deep drawing
Deep drawing is the one of the forming processes used to deform the shape of the sheet metal acording to our desired shape with the help of die. This processes is used to create an emboss in the hood inner panel. Above fig shows the step by step operation of the deep drawing processes. Here, which a sheet metal blank is radially drawn into a forming die by the external force given through the punch.
2. Hemming
Hemming is one of the sheet metal forming processes which sheets are joined by bending into 180 degree. Here we used hemming to join hood inner panel and hood outer panel. In this processes, usually a sheet is bent with the help of nner sheet in three different stages, those stages are shown in above fig. Mosty we use two different methods for hemming operations. Which is Conventional die hemming and Roll hemming. In conventional die hemming we use die for the hemming operation.And in roll hemming we use roller to hem in all the corners of the sheet metal.
Final assembly
Conclusion
All the parts of Back door is designed and assembled by using NX CAD. Here we gave 0.75mm thickness for both outer panel and the inner panel. And also we gave a proper mounting for Hinge, Gas stay, Wiper motor and latch & striker mounting.