Design of backdoor

AIM:

To design the car back door by using the given styling surface.

OBJECTIVES:

The main objective of this project is to,

• To design the backdoor using styling surface by considering the design standards.
• Need to design the inner panel,outer panel and necessary reinforcements and embosses.
• The inner panel should be done draft analysis to check wether it satisfys the manufacturability of the design.

BACK DOOR:

The boot space of the car on back side is the main storage for all the vehicles often has a door on the rear side of the vehicle it is called as Tail gate. These doors are operated in many ways like manually, electrically powered. This is the main crusial arear most of the accidents may occur in this area care should be taken while designing that during the crash should not effect the passengers.Back door is manufactured with steel and alluminium for manufacturing.Mostly steel will be used for light weight and less cost.For all premium cars alluminium will be used for strong door. back door consists of outer panel,inner panel and some reinforcements.

TYPES OF DOORS BASED ON OPENING:

• TOP MOUNTED DOOR:

• SIDE MOUNTED DOORS:

• BOTTOM MOUNTED DOORS:

BASED ON TYPE OF OPERATION:

• MANUALLY USING GAS STAY DOORS:

• ELECTRICALLY AND SENSORED OPERATED DOORS:

INPUTS CONSIDERED FOR DESIGNING THE BACK DOOR:

• Class A surface given
• Outer panel thickness 0.75mm
• Inner panel thickness 0.75mm
• Reinforcement thickness 1.0mm
• Draft angle minimum 7degress

GIVEN CLASS A SURFACE OUTER UPPER & LOWER PANEL:

TOOLING DIRECTION:

Tooling axis is created for draft analysis to check weather the designed component is manufacturable or not.Tooling axis is craeted by joing with one line from one direction end to other end after drawing the line another line is drawn perpendicularly. the perpendicular line drwan is the tooling axis.

DRAFT ANALYSIS:

BACK DOOR ASSEMBLY PARTS:

1. Outer panel
2. Inner panel
3. wiper motor reinforcements
4. Hinge reinforcement
5. gas stay reinforcement
6. latch and sriker reinforcement

• OUTER UPPER AND LOWER PANEL:

Outer upper and lower is the styling surface of the back door.For this outer panel rear view visibilty purpose glass will be mounted on the panel.For this outer panel head lights also will be mounted on either sides.For outer lower panel nuber plate will be fixed. The both upper and lower panel will be joined by spot welding on the inner side of the flange for not effecting the styling surface.These outer panel will be fixed to the inner panel by hemming and by placing mastic sealent.

• INNER PANEL:

Outer panel is assembled to the inner panel.inner panel is made of steel or alluminium material.For top end cars inner panel is made of alluminium material for strong and rigidity.Inner panel has several mountings for attachments like gas stake,hinge attchment,wiper attachment and latch and striket attachments purpose.For this inner panel several reinforcements were attached in the provided embosses.

REINFORCEMENTS:

Reinforcement is the extra material was provided at some areas to strengthen that places.Generally the thickness of the reinforcemnets are varied between 1mm to 1.5mm.In the design i have designed the reinforcemnets by extracting the geometry by using wave geometry linker option and extracted and trimmed as per the required size.

• Wiper motor reinforcemnet:

Wiper motor reinforcement is created to add strength at the wiper motor mounting place.

• Latch & striker reinforcemnet:

Latch and stiker is a mechanism where lockin of the door is done.Due to repetedly opening and closing of the door to strengthen that area we are using reinformnent with 1mm thickness as extra material.

• Gas stay reinforcemnet:

Gas stay is a device used for openng the door with slight man oper while opening at certain position it retains into one fully opening position.One end is fixed to the car body and other end is fixted to the inner panel.Emboss iscreated to the inner panel.To compensate the strength to it reinforcement is attached with 1mm thickness.

• Hinge reinforcement:

Hinge acts as a attachemnent for opening and closing of the door.One end of the hinge is attached to the car body and other end is attached to the inner panel where emboss is created.Same to compensate the strength of the emboss we are attaching the reinforcement with 1mm thickness to it.

BACK DOOR DESIGN ASSEMBLY:

CORNER RELIEF:

JOINING PROCESS:

• HEMMING:

Hemming the process for forming process.A roller is passed on the edge of the outer pannel for 2 to 3 times by applying the presseure on the sheet.A gap must be maintained between the inner pannel and outer panel on both sides.

• SPOT WELDING:

Spot Welding is a form of resistance welding also known as Resistance Spot Welding . Spot Welding involves using heat produced by resistance to an electrical current to join materials together. The current heats the materials to a point where they become malleable. The use of strong pressure bonds them together. Another form of resistance welding is Projection Welding. This process involves fusing a fastener’s embossed or coined projections to the metal base material to form a weld. As the materials never melt, they do not intermix. This means the resulting weld is more like a forging of the materials.

The outer inner and lower pannel is joined with spot welding process.

• MASTIC SEALANT:

As we know that main pupose of outer panel is for classy look of the surface by covering the inner panel, to join inner pannel with outer pannel we cannot use regular joing procedures like welding,riveting,using fastners etc. these will destroy the classy surface of the outer pannel. To eradicate the above problems we have using the mastic sealents and hemming operations.Mastic sealent behaves like a elastic rubber.It is like a paste we apply between outer and inner panel we have designed some space to apply the paste.Intially it is like a jelly after heating it will be hardened and expanded upto 5mm and stick in between outer and inner panel.It also reduces the vibrations and some disturbances, acts like a dampers.

CONCLUSION:

As per the design standards back door was designed with necessary reinforcements and draft analysis.