Design of backdoor

AIM:

To design the back door assembly of a car by using the given class A surface(skin) by the approximate design methodologies and provide the necessary reinforcement and to study the draft analysis

INTRODUCTION:

An automobile back door or Tailgate is the panel that covers the boot (or trunk) 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.

TYPES OF TEST IN BACKDOOR:

• Bend test(two corners & hinges are fixed and apply force to the door to find up to what force the door regains its structure after removing force )
• Dent test
• Endurance test(no of cycles of door opening and closing)
• Abuse case

Top-Mounted :

This type of back doors is used in a station wagon, pickup truck and some of the sport utility vehicles. Today’s modern cars use top-mounted tailgating systems which are both powered and also gas stay supported. These top mounted tailgates provide greater rear visibility compared to side-mounted or bar doors which have canter pillars in it.

Side mounted

It is generally used in van type MPVs, SUVs, pickup truck vehicles. These side mounted door/barn doors are a lot easier compared to top mounted ones. These doors are generally small in size and can be easily accessed. These doors are more convenient for the goods handlers carrying lengthy objects, long pipes where one door is kept open. It also saves accidental head impacts. It is a lot easier to load /unload things in vehicles having side-mounted doors.

Bottom mounted

Bottom type or split type backdoor system is used in estate type cars, pickup trucks and some luxury SUVs. These are most convenient type of backdoor in which the bottom split is used as a support or even as a table for the touring people.

ALUMUNIUM DOOR:

• Parts are casted,so the local thickness can be varried
• Reinforcement can be neglected
• comparitively lighter in weight to steel
• Has less no of components
• finally,price of the product is higher

STEEL DOOR:

• Parts are stamped,so the thickness is uniform
• Reinforcements are necessary
• it is heavier in weight when compared to aluminiun
• It has more no of components
• price of the proiduct is lower

TYPES OF SHEET METAL OPERATIONS

• Hemming
• Punching
• Deep drawing
• Blanking
• Embossing

Design considerations

• Rear visibility
• Boot space & accessibility
• Sealing Flange
• Support structures like hinges and gas stays.
• Mounts for wiper motor, tail lamps and other wiring loops
• Rear crash regulations
• Joining techniques such as hemming, spot welding etc.
• Gap and flush requirements

COMPONENTS IN BACKDOOR ASSEMBLY:

• Inner panel
• Outer panel upper
• Outer panel lower
• Necessary reinforcements
• Hinge assembly

Inner panel

Outer panel

Necessary reinforcements

Hemming with corner relief:

Assembly:

DRAFT ANALYSIS:

Latch and striker trajectory:

TOOLING DIRECTION:

Conclusion:

Car back door was designed using the given styling surface, and under provided design regulations.