Design of backdoor

CAR BACK DOOR DESIGN

AIM

To design the back door of the car using given outer class-A surface

Introduction

A door that is located at the rear side of a car gives access to the boot space to store luggage spare wheels etc. These doors can be operated manually or electric powered. In most luxury cars door is electrically operated.

TYPES OF DOORS BASED ON WORKING POSITION-

1. Top Mounted Door

1. Side Mounted Door

1. Bottom Door

BACK DOOR PARTS-

Inner panel

Outer Panel

Hinged and its reinforcement

Gas stay reinforcement

Wiper Motor reinforcement

Latch & stricker and its Reinforcements

Different sheet metal operations used for manufacturing

Deep Drawing

• The metal deep drawing process is on an effective method of manufacturing of cups, cans and similar deep drawing products.

The deep drawings have two main categories.

• First Stage Drawing

The blank shape of the material is placed on the die and in contact with the punch. When the metal specimen is a flat piece of metal used in forming and finishing the product. Initially, the punch moves in a downward direction. The outer rim of the blank was subjected to pure radial drawing( drawing toward vertical axes) between the die and blank metal. The metal becomes a bend and slides over the die and is also stretched between die and punch.The metal in the vicinity of the punch head and contact with it bend and slide over radii and stretch over the punch head.

• Redrawing

The components are drawn from the first stage again it is redrawn and converted into more depth to form a cup shape in the die and punch. The second stage is called redrawing.

Embossing

• Embossing is a metal forming process for producing raised or sunken designs or relief in sheet materials by means of matched male and female roller dies theoretically with no change in metal thickness or by passing sheet or a strip metal between rolls of the desired pattern.
• The metal sheet is drawn through the male and female roller dies producing a pattern or design on the metal sheet. Depending on the roller dies used different patterns can be produced on the metal sheet.

Materials commonly used in the metal embossing process include-

• Aluminum alloys
• Steel alloys
• Zinc
• Copper
• Brass
• Cold rolled sheet

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 heming operations are used to connect parts together to improve the appearance of a part and reinforce part edges.

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

There are various types of hemming operations.

Conventional die heming

conventional die hemming, the flange is folded over the entire length with a hemming tool.

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 an open hem, the bend angle is equal to 180 degrees.

Tear Drop Hem

In tear drop hem the bend angle is greater than 180 degree.

Closed heming

Hems without any inside rdious are called as closed hem. Closed hems are not are not recomended if the hem geometry is to be painted or if the material used is SST or alumium.

Blanking

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

Punching

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

Design of Back Door in NX 12 CAD software-

Door Parts thickness is given below

1. Outer Panel
2. Inner Panel
3. Reinforcements

CLASS-A SURFACE

• Given surfaces has to be repaired according to the smoothness. After repairing the surfaces, the door is divided into two parts an upper and lower panel.

• First, we need to create the tooling direction for the deep drawing operation. It shows that all the operations like embossing are done by considering this vector direction and it will help in manufacturing the part,

• After that, we have to create a sealing flange by offsetting the outer panel to the specified distance.

• Then we are creating the back door inner panel by offsetting the outer surface at a distance considering the sheet thickness and thickening direction.
• Then created the connecting flange to join the inner panel and sealing the flange.

• Then to improve the strength of the inner panel and to reduce the weight Y y-type emboss and other cut-outs are created. Also, for Latch and Stricker mounting cut-out is also done on another side of the inner panel to maintain the center of gravity of the back door.
• Another Emboss is created for wiper motor mounting.

• Another flange is created to reduce the vibration of the door by joining the inner panel and outer panel by `Mastic Sealant.

• Now to assemble the Back door with the vehicle hinges are used to open and close the door. For That to increase the local area strength we have to design the emboss and provide the appropriate reinforcements to withstand load acting upon it.

Hinge reinforcement

• For positioning the latch and striker we have to create a trajectory passing through a midpoint of the line/ axis of two hinge mounting holes.

Latch & Striker Emboss

Gas Stay Emboss and Reinforcement,

Wiper Motor Reinforcement

Hemming and Hem Relief

Assembly

DRAFT ANALYSIS

INNER PANEL