Design of backdoor

AIM: Design a back door using NXCAD

OBJECTIVE:

To design a back door from the given class A surfacing,inner panel is designed and assembled with hinge reinforcements,Gas stay reinforcements,wiper motor reinforcements and latch reinforcements.

Introduction:

The trunk or boot of a car is the vehicle's main storage or cargo compartment, often a hatch at the rear of the vehicle. It is also called a tailgate.In Indian English the storage area is known as a dickey (also spelled dicky or diggy), and in South-East Asia a compartment.

The trunk or luggage compartment is most often at the rear of the vehicle. Early designs had an exterior rack on the rear of the vehicle to attach luggage trunk. Later designs integrated the storage area into the vehicle's body, and eventually became more streamlined.The main storage compartment is normally provided at the end of the vehicle opposite to which the engine is located.

The door or opening of a cargo area may be hinged at the top, side, or bottom.

If the door is hinged at the bottom it is called a tailgate, particularly in the United States. They are used on station wagons and pickup trucks, as well as on some sport utility vehicle (SUV).If the door is hinged at the top it is termed a hatch, and is used on a hatchback.A bottom opening door is now common on SUVs.

Designing and Reinforcements:

Outer Panel:

The outer panel is the styling surface of the back door.The coating provided is of multi stage which has the property of scratch resistance,rust prevention,smooth and attractive finishes.It also has the provisions for the tail lamp,rear fog lamp and licence plate mountings.Its thickness in the range of 0.65-0.75 mm.

Inner Panel:

The inner panel is a component which is used for strengthening the door.Its thickness in the range of 0.65-0.75 mm.Its one of the most components on which all accessories are mounted like hinges,Gas stay,wiper motor,Latch and striker etc.The possible method is the integration method.In this method the part is stamped out of a single blank.This reduces the no of tools needed the assembly cost and eliminates any fit ability problem.

Reinforcements:

Hinge Reinforcement:

It enables the opening and closing of the back door.one end of hinge is fixed on the back door and other end on the roof,on both sides.Hinges can be placed inside or outside of the back door.The reinforcements are added to this region to compensate for the weak zone developed due to the load acting while opening and closing of the back door.

Gas stay Reinforcement:

Gas stay is a device used for supporting the back door in its opening position.It requires no man power and is engaged into supporting position automatically as the back door opens.one end is fixed on the back door and the other end is fixed on the body side.The reinforcements are added to this region to compensate for the weak zone developed at gas stay region.

Wiper motor reinforcement:

It is used to mount the wiper motor assembly.

Latch Reinforcement:

It forms the locking mechanism of the back door.Due to regular opening,closing and over slamming of the back door,there is stress developed in the Latch and striker area.During rear collision this area will be the first point of contact.Reinforcements are added to this region to compensate.

Reinforcements assembly:

Hemming:

Hemming is the process of wrapping to the flange of outer panel to the flange of inner panel so that they are fitting rigidly.After hemming process,the sealants were applied along the edge of the flange of outer panel so that water tightness is achieved.

Mastic sealants:

To improve NVH ie to reduce these levels.They are made of hard rubber and are introduced as a paste thereby joining the inner and outer panel with a thickness of 5 mm.Mastic sealants are preferred over spot welding to join the inner and outer panel so that reduces the aesthetics of the car,especially on the outer panel.

Draft analysis:

While designing a component a design engineer must make sure that component that can produced by any means of manufacturing methods with least amount of time,material,man power and power,so that we can reduce overall cost of the car.when it is manufactured by deep drawing at the most of the time.Deep drawing is the process where the single sheet of metal is place over the die which has the desired shape of the final output and the sheet is pressed against it with a tool.

Conclusion:

Thus the back door was designed and developed from the given styling surface with essential reinforcements and emboss using NX CAD.