Challenge

DESIGN OF AUTOMOBILE BACK-DOOR

BBanala Sumith2 Apr 2021

AUTOMOBILE BACK-DOOR

OBJECTIVE:

To design a Backdoor (Tailgate) of a car by adding the reinforcements to its assembly parts in Siemens NX CAD.

INTRODUCTION:

BACK-DOOR/TAILGATE:

A door is a hinged part used for entry and exit of the vehicle. Back-doors are one of the types of doors which are located next to the passenger seat which provides access to the luggage compartment. This door is mostly used in passenger cars to avail of a large amount of luggage space in the backside. It is a single-stamped part that provides more space by bulging out and provides an aesthetic outer appearance.

Actually, this door is actuated by a motor for opening and closing which is called a powered trunk lid system hatchback.

TYPES OF BACK-DOOR:

The back-doors are classified according to their positions and design requirements of the vehicle.

TOP MOUNTED:

These are the regular type of door model used for Modern and luxurious cars, which are both powered and also gas stay supported.

SIDE MOUNTED DOORS:

As the name signifies side-mounted doors are the one which used for SUV’s, pickup trucks, etc. These doors are small in size and easy to handle. Compared to the top-mounted door it provides more safety.

SPLIT TYPE DOOR:

This door system is used in convenient provision for tour vehicles which provides more space for luggage by closing the single door as shown in the figure.

OPENING AND CLOSING MECHANISMS:

GAS STAY TYPE:

This type is most commonly used and called an ideal mechanism from base model cars to top-end models. It is activated manually and holds at its position unless and until the force is applied for closing it.

POWER LIFTED MECHANISM:

It is the mechanism used where the backdoor is of more which may not be held at the opening position by having the normal gas-stay. This mechanism helps in opening and closing the door automatically by a remote sensor. In this there is a special feature is inserted which helps in avoiding the accidental hand insertion called pinch switch, which alerts the system when the hand is in between the door while closing.

DESIGN CONSIDERATIONS:

Rear visibility criteria, provide the rear-view mirrors for visual convenience to drivers as per the FMVSS (Federal motor vehicle safety standard)
The positioning of the hinge should be perpendicular to the latch when they are in contact with each other.
A perfect clearance should be provided for sealing flange which protects from flushing the water into the vehicle when the door is closed.
A gap of about 2-3mm is provided between the parts for mastic sealant applying, which helps in harness and vibration gradient.

MANUFACTURING TECHNIQUES:

The deep drawing should be done by following the tooling direction and a single part should be produced.

Blanking or piercing operation should be performed for trimming off the excess material.

Hemming should be done where the sheets are folded over another part in order to achieve a close fit by connecting the two parts.

Laser brazing is performed on the two outer panels by leaving the soldered material between the two bodies as shown in the figure.

ASSEMBLY PARTS:

DESIGN OF BACK DOOR:

TOP OUTER PANEL:

This the skin or surface part provided by the styling team, modeled according to the requirements by consulting the design team.

BOTTOM OUTER PANEL:

SELING FLANGE:

This flange is created by offsetting the perfect distance in order to prevent the water from outside of a vehicle.

TOOLING DIRECTION:

This is the direction for producing the part which is set at the angle by taking the deep drawing considerations.

INNER PANEL:

This is the main part of the back door, In this, we have provided the V-shape embosses provision for safety when it takes an accident and trimmed the portions in-order to decrease the weight of the part.

Made a provision for the hinge attachments, gas stay attachments, and by taking the hinge center as axis added the latch attachment provision.