Design of backdoor

     BACK-DOOR DESIGN

OBJECTIVE:

use the providing styling surface to come up with a backdoor design & use appropriate design methodologies and nessecary embosses and the reinforcment to complete the design.

SOFTWARE USED:

NX CAD

BACKDOOR INTRODUCTION:

An automobile backdoor is the pannel that covers the boot(or)trunk of an automobile.it enables acces to the main luggage compartment.A hinge that allows the boot lid to be raised ,while devices such as gast stay used to hold it up in the open position and the backdoor is an assembly of an many parths such as the inner pannel,outer pannel upper,outer pannel lower,reinforcment,and the inner pannel is attached to the outer pannel by using the mastic sealent and the hemming process.

DESIGN CONSIDERATION OF THE BACKDOOR

• Rear visibility criteria..OF
• Functional requirment of the gas stay and the hinge axis.
• Luggage volume.
• Crash analysis.
• Bend test,Crash test,Tortion test and Endurance test.
• Rear crash regulation.
• gap and flushness requirment.

TOTAL NO.OF.PARTS IN THE BACKDOOR ASSEMBLY

• Outer pannel upper.
• Outer pannel lower.
• Inner pannel.
• Hinge reinforcment.
• Gas stay reinforcment.
• Stricker reinforcment.
• Wiper motor reinforcment.

BACKDOOR OUTER PANNEL:

The back door outer pannel is tthe styling surface of the backdoor,the other parts of the backdoor are designed with the reference of the styling surface,it acts as the outer pannel and deals with the asethetics of the car.

in this design the outer pannel is divided in to two parts 

• Outer pannel upper 
• Outer pannel lower

• The outer pannel is extracted from the styling surface 
• And the pannel is alter or the required design using the nx cad software
• The thickness of 0.75mm is given to the outer pannel
• And at lastthe Hemming process is done.

IMAGE OF  OUTER PANNEL:

INNER PANNEL DESIGN

 

TOOLING DIRECTION:

• Before starting the design of the inner pannel the tooling direction must be given for the deep drawing process
• and then the styling surface must be checked because it may have some irregularities and it may cause trouble so the checking should be done.
• And the design of the backdoor is done by the Top down approach.

REINFORCMENT AND MASTIC DATA POINTS

The parts of the back doors and the reinforcment 

• Hinge mounting area and hinge reinforcment 
• Gas stay mounting area and gas stay reinforcment 
• Wiper motor mounting area and wiper reinforcment
• Striker mounting area and skriker reinforcment

HINGE AXIS ,MOUNTING AREA AND REINFORCMENT 

• The hinge area enables the opening and the closing of the backdoor and the one end of the hinge is mounted on the backdoor and the other end on the roof .
• The hinge reinforcment are added to compencate the weak region due to the acting load over it.

WIPER  MOTOR MOUNTING AND REINFORCMENT

The wiper motor reinforcment is used to mount the wiper motor assembly.

GAS STAY MOUNTING AND REINFORCMENT

Gas stay is a device that is used to ssupport the back door when it is in the open condition .

Gas stay requires no man power and it is engaged into the support position automatically as the back door opens .

And the one end of the Gas stay as fixed to the back door and the other end is fixed with the stationary area

Emboss is provide is provided in the gas stay area to compensate the weakness and improve the strength.

LATCH AND STRICKER REINFORCMENT.

• The latch and stricker embosses were designed by creating a traectory that follows the opeaning and closing of the backdoor with the rescept to hinge axis. 
• The position of the hinge axis should be prependicular to the latch when the latch and the stricker meets the circle is drawn from the center of the hinge axis to find the path of the strikerand positioned perpendicular to the path.

HEMMING AND THE CORNER RELIEF.

• Hemming is an metal working process in which the sheet metaledge is rolled over on to itself.
• Hemming is the process in which the edge is rolled flushed to to itself.
• The outer pannel is designed as two parts named as outer pannel upper and outer pannel lower
• after designing the outer pannel the hemming was created by offsetting the surface with the help of the face blend.

CORNER RELIEF:

The corner relief is given to reduce the stress concentration along the corners and also to avoid the shrink marks along the corners and this is done by trimming the corner by minimum radius for the roller s to pass by smoothly.

MASTI SEALENTS:

DRAFT ANALYSIS:

Draft analysis is done to show that the part can be easily drawn out from the mould.

• The draft analysis will be formed for the tooling direction created at the first and checked that the model is suitable for manufacturing .
• Then to get the complete green portion the necessary changes to the draft angle  of the embosses and the law extention were carried out by optimizing the model.
• the draft analysis command enables us to detect that the part can be easily drawn out from the mould or not.

 

ASSEMBLY IMAGES:

 

CONCLUSION;

Thus the back door was designed from the given styling surface and the draft analysis is also done on the inner panel to check the manufacturing conditions.in this challange i learned to design the inner pannel,outer pannel,wiper motor reinforcment,hinge reinforcment,gas stay reinforcment,latch and striker reinforcment and its position.