Design of backdoor

BACK DOOR DESIGNING

Object- To design the back door by using provided styling surface and to develop necessary reinforcement and emboss.

Introduction -

             The door which is fitted back side of the vehicle normally in four wheeler is called back door or rear door. There is a luggage space or we can shift into seat. For covering this area we use back door.

Back door designing consideration -

              Back door is divided into 2 or 3 parts. Outer panel and inner panel or outer panel upper, outer panel lower and inner panel. Both these (inner panel and outer panel) are jointed with hemming flange and some area we use mastic bead. For strengthen of this we provide emboss in the inner panel. Emboss should be inside in the panel. So that if crash is happen from back side then first emboss should be damage. Emboss is given according to crash analysis that if vehicle is crashed from back side then the force which comes on the panel is divided towards upper direction and lower direction, not in towards Y or V shape like hood panel. While giving emboss we use to keep in mind the draft angle so that emboss is done easily. Normally draft angle we keep 7 degree. It should not be less than 3 degree. Then sealing flange is given in it. When the door is closed then sealing flange is attached with rubber then it provides safety from dust and water. The door when it opens towards upper side then it is assembled with gas stay. With the help of gas stay door opens easily with low force or without force. And going up and stopping easily. For more strengthen of back door we provide reinforcement in some palace. Such as it is provided in sealing flange in some place and both side of hinge reinforcement, both side of gas stay reinforcement, wiper motor reinforcement and latch & striker reinforcement. All these reinforcements are provided in inside with inner panel and welded with by spot welding. In this where the windshield is fitted there we use brazing for joining between inner panel and outer panel. According to the rear visibility criteria we fit the windshield glass in this.

Part of Back Door -

1. Outer Panel Upper- It is the outer part of back door, called as a outer panel upper. A lot of color is painted on it for looking good. It is jointed with inner panel with hemming flange and some mastic bead.

2. Outer Panel Lower- It is the outer pannel lower. Many of the vehicle back door outer part is devided into two part, upper and lower. Both these are jointed with spot welding. And jointed with inner panel by hemming flange.

3. Inner Panel- It is a inner panel, main strength part. Sealing flange is situated in it. And many emboss is given on it for strengthen. Every reinforcement is attached with it.

4. Hinge Reinforcement LH- Reinforcement use to give for increase the strength. So where the panel taking more force there we provide reinforcement.

5. Hinge Reinforcement RH

6. Gas Stay Reinforcement LH

7. Gas Stay Reinforcement RH

8. Wiper Motor Reinforcement

9. Latch & Striker Reinforcement

Back Door Design Methodology –

               First of all we repair the given styling surface on the right way and then sew it. After it we linked this with outer panel upper, outer panel lower and inner panel. And again by doing extract surface we create hemming flange with the help of swept command. Similarly we made lower panel and provide necessary clearance and modification in it. Hence outer panel was ready. Again similarly also for inner panel we use styling surface as a reference. And then offset it on appropriate distance and trim it all area except of sealing flange and with the help of law extension and keep in mind draft angle we create sealing flange. Again after it according to crash analysis we create emboss inside in the inner panel. At where the load exerted more there we provide reinforcement such as hinge reinforcement, gas stay reinforcement, wiper motor reinforcement, latch & striker reinforcement. For right palace of hinge emboss and striker emboss we draw a trajectory sketch and verify it.  In making it we often give more than 10 degrees draft angle. In making it we mostly use the command offset surface, trim surface, extract surface, law extension, swept, through curve mesh, etc.

Draft Analysis- In this part we have taken the draft angle more than 7 degree. Draft angle is given for realising the part in die and punch. Draft angle should not less than 3 degree. If it is less than 3 degree then the wear of punch is more. In this part green area ( greater than 7 degree) is ok but some area is looking yellow because it is made lancing and then bend it, so there is no need of draft angle. Some area will be in red color because these area are not made by emboss, it made by other method.

Green color means- Draft angle is greater than 7 degree.

Yellow color means- Draft angle is 0 to 7 degree.

Blue color means- Draft angle is 0 to -7 degree.

Red color means- Draft angle is less than 7 degree.

Conclusion –

               In this project we learnt more thing that how to make design of back door and what is the basic parameter of this designing where should be provide the reinforcement and what parameter we keep in mind for inner panel emboss designing.