Design of backdoor

DESIGN OF BACK DOOR / TAIL GATE

What is Back Door?

Backdoor are one of the type of door of the vehicle which are located next to the passanger seat which provides access to the luggage compartment. Also covers the Rear side portion of the car.

Design considerations of Back Door

• Functional Requirements of Door open/close gas stay location
• Rear Visibility Creteria
• Rear crash Requirements
• Sealing Flange & its functions
• Joining Techniques - Hemming , Spot welding & mastics.

Parts of Back Door

• Outer panel

• Inner panel

• Gas Stay reinforcement Lh/Rh

• Hinge reinforcement LH/RH

• Wiper motor reinforcement

• Latchet striker Reinforcement

Selection of material

ALUMINIMUM	STEEL
Parts are casted	Parts are Stamped
No Reinforcements needed	Need to provide Reinforcement
Can produce variable thickness	Uniform thickness
Light weight less component	Heavy weight more component
High cost	Low cost

In Aluminimum there is no need to giving minimum draft , thickness & radius of 3mm+ thickness. We can produce the part even in the drft angle of 3 degree. Due to that we have high range of Rear visibility criteria & more lugguage space.

Designing of Back Door

Check the given class A component using sew command whether the given class A is having any gap and repair the problem creating areas before proceeding in tot the further design process.

To repair a Class A surface the following commands has been used

• Bridge curve

• Through curve mesh

• Extended sheet

• Face blend

• Blend corner

• Offset in face

• Trim Sheet

• Sew

Outer Panel lower Side

Outer Panel flange width should have minimum of 8mm.

Repaired Class A

Back Door Inner Panel

The major reason to create the inner panel is to strengthen the part by providing embosses and reinforcements to the panel. Due to styling concern we cant able to given an emboss or other reinforcements to the Outer Panel.

Before going to design process of inner panel creation of tooling axis is mandotry

Tooling Axis

The tooling axis is the point which direction the tool travels and eject the component. The Minimum draft angle for the sheet metal is 7 degree. Anything less than 7 degree will affect the tool life and cause damage to the product. In the steel material we are going with the stamping process which has some uniform thickness, radius and creation of reinforcements.

Sealing Flange

A flange seal prevents leaks by correcting any minor irregularities or even larger spaces between the faces of each flange. Some seals are built into the flanges themselves, while others consist of rubber rings or similar materials that are cut to fit the flange during installation.

• The minimum sealing flange width is 30mm.
• Inner panel offset of 1.7mm.
• Minimum flange for hemming is 8mm.

Connecting Flange

Windshield area

Reinforcement Mounting

Y & v Emboss

The creation of Y and V emboss is to desipate the energy outside the car and creates strength to the area during various bend test of the backdoor or during any collision.

When ever the load applies to the back door panel the force travels towards y and v direction. This is the reason for creating the Y and V embosses.

The various test carried out innthe Back door are as follows:

• Bend test
• Torsion test
• Abuse test
• Dent test
• Assembly Load cases
• Enndurance test

Mastic Sealent Area

The mastic sealent should have 5mm of gapbetween the outer and inner panel.

Hinge mounting & Gas Stay LH/RH & Wiper Motor

Latchet Striker Mounting

Final Backdoor Inner Panel

Draft Analaysis

BACK DOOR OUTER PANEL

The Outer panel is the styling area which gives the decent look to the car. We dont provide any emboss or reinforcements to the outer panel.

Hemming Process

The Hemming process is one of the method used in the joining process of sheet metal. There should be a 0.2mm gap betwwen the outer and inner panel in the hemming area to give space for the mastic sealants.

Outer Panel Upper part

• Using Swept command hemming process can be designed.

Outer panel lower part

Relief Angle clearence

HINGE,GAS STAY & WIPER MOTOR REINFORCEMENT

What is need of Reinforcement?

When we are mounting the additional component to our inner panel on the particular area the strength of material will be reduced, inorder to compensate the loss of strength we are introducing the reinforcement to the part.

LATCHET STRIKER REINFORCEMENT

Differential views of Back Door