Design of backdoor

Aim :

To develop the car Backdoor(Tail gate) with the reference of given skin data as per engineering standared by using NX12

Back Door :

The Back door is typically hinged, but sometimes attached by other mechanisms such as tracks, in front of an opening which is used for entering and exiting a vehicle.

A vehicle door can be opened to provide access to the opening, or closed to secure it. These doors can be opened manually, or powered electronically. Powered doors are usually found on minivans, high end cars, or modified cars.

Functions of the Backdoor:

• It protects the occupants and luggage from getting damaged.
• It houses assembly of tail lamps, wiper motor and other components.
• It houses windshield glass which helps in rear visibility.
• Parking sensors, rear view camera are mounted on it.

Types of Backdoor based on working positions:

The door or opening of a cargo area may be hinged at the top, side & bottom. If the door hinged in the bottom it is called as a tailgate.

1.Top mounted

2.Side mounted doors

3.Bottom type

1.Top mounted:

This type of back doors is used in a station wagon, pickup trunk and some of the spot utility vehicles. Today's modern cars use top mounted tailgating system which are both powered and also gas stay supported. These top mounted tailgates provide greater rear visibility compared to side mounted or backdoor which have center pillars in it.

2.Side mounted door:

As the name signifies the side mounted doors are the one which is used in the van type MPVs, SUVs, pickup truck vehicles. These side mounted doors or barn doors are a lot easier compare to top mounted doors. These doors are generally smaller in size and can be easily accessed. These doors are more convenient for the goods handlers for long pipe and lengthy components where one door is kept open. These door also save accidental head impacts. It is a lot easier to load and unload items in the side mounted doors

Types of Back Door :

1. Top Mounted
2. Side Mounted
3. Bootom Mounted

Top Mounted Back Doors :

Side Mounted Back Door

Bottom Mounted Back Door :

Design Consideration :

• Visibility Criteria
• Latch and Stricker Position
• Hing Position
• Gas Stay Position
• Space Avalibility
• Drain Holes
• Hemming and Relief area's

Components of Back Door :

The Components of Back Door as follows,

1. Inner panel
2. Outer panel
3. Hinge and its reinforcement
4. Wiper motor reinforcement
5. Latch & stricker and its reinforcement

Inner Panel :

Inner Panel :

Gas stay Reinforcement :

It is used to lift up the Tail gate.

There are two types of Gas stay reinforcement is there. That they are

1. Manual System
2. Power Lift System

Manual System :

This mechanism is most used in Indian cars. It is operated man by his own.

Power Lift System :

It works on the basics of Sensor.

Latch Reinforcement :

A latch is not the same as the locking mechanism of a door or window, although often they are found together in the same product. Latches range in complexity from flexible one-piece flat springs of metal or plastic, such as are used to keep blow molded plastic power tool cases closed, to multi-point cammed latches used to keep large doors closed.

Wiber moter Reinforcement :

It is small electric motor which is mounted in the rear Tail gate. It used to clean the rear wind sheid for clear visiability.

Outer Panel :

Corner Relief:

Relief helps to control sheet metal behavior and to prevent unwanted deformation during unbend operations. So here i gave two corner relief for Back door.

Hemming:

Hemming is a forming operation in which the edges of the sheet are folded or folded over another part in order to achieve a tight fit. Normally hemming operations are used to connect parts together, to improve the appearance of a part and to reinforce part edges.

In car part production, hemming is used in assembly as a secondary operation after deep drawing, trimming and flanging operations to join two sheet metal parts (outer and inner) together. Typical parts for this type of assembly are hoods, doors, trunk lids and fenders.

There are various types of hemming operations:

1. Conventional die hemming: In conventional die hemming, the flange is folded over the entire length with a hemming tool.
2. Roll hemming: In roll hemming, the hemming roller is guided by an industrial robot to form the flange.

Open Hem: A Hem has a full round feature and a return flange. In open hem bend angle is equal to 180 degrees.

Tear drop Hem: In tear drop hem the bend angle is greater than 180 degrees.

Closed Hem: Hems without any inside radius are called as closed hem. Closed hems are not recommended if the hem geometry is to be painted or if the material used is SST or Aluminium.

Blanking:

Blanking is a cutting operation of a flat metal sheet and the article punched out is known as blank. Blank is the required product of the operation and the metal left behind is considered as a waste.

Punching:

It is similar to blanking only the main difference is that, the hole is the required product and the material punched out from the hole is considered as a waste.

Design of Back door in NX CAD:

Door parts thickness is given below,

1. Outer Panel - 0.75 mm
2. Inner Panel - 0.75 mm
3. Reinforcements - 1.5 mm

Given Data,

Given surfaces has to be repaired according to the smoothness. After repairing the surfaces, the door is divided into two parts as Door Outer Upper and Doo Lower Panel.

1. Wiper Motor Reinforcement

Hemming & corner relief:

Hemming is a forming operation in which the edges of the sheet are folded over another part in order to achieve a tight fit. Usually hemming operations are used to connect parts together, to improve the appearance of a part and to reinforce part edges.

Positioning of Latch & striker/ Latch Trajectory:

Backdoor is the swinging part which rotates about hinge axis. The position and orientation of latch striker is important for proper opening and closing of the backdoor. The positioning is done by sketching a circle with center as the axis of the hinge which passes through the striker at appropriate position with respect to inner panel.

.

CONCLUSION:

• The back door outer and inner panel were designed with the help of the styling surface along the tooling direction.
• Draft analysis was performed on the inner panel and All the reinforcements were designed and placed at appropriate positions.