Challenge

Design of backdoor

SSyed Faizan8 Oct 2022

AIM:--Use the provided styling surface to come up with a back door design, use appropriate design methodologies, and provide the necessary reinforcements and embosses.

ANSWER:--

WHAT IS BACK DOOR IN AUTOMOBILES ?

`>->>` Back door is something which covers the rear part of the vehicle, It also provides saftey from rear part.

`>->>` "Back door are one of the type of door of vehicle which are located next to the passenger seat which provides access to the luggage compartment ,In most of the cars it operates with gas stay / Power spindel which reduce the effort required to lift the door".

PARTS THAT ARE USED IN CAR BACK DOOR:--

ROOF UPPER OUTER.
ROOF LOWER OUTER.
GAS STAY/POWER SPINDEL.
GAS STAY REINFORCEMENT LEFT AND RIGHT.
HINGES.
HINGE REINFORCEMENT LEFT AND RIGHT.
LATCH AND STRIKER.
LATCH AND STRIKER REINFORCEMENT.
SEALING FLANGE.

OPENNING AND CLOSING THE DOORS:--

THROUGH GAS STAY.
THROUGH POWER SPINDEL.

THROUGH GAS STAY:--

THROUGH POWER SPINDEL.

AUTOMATIC OPENNING AND CLOSING OF A BACK DOOR:--

OPENNING:--

CLOSEING:--

If we press the button the the door will be closed automatically.

LOAD CASES-GENERAL ANALYSIS TESTS:--

BEND TEST.
TORSION TEST.
ABUSE CASES.
DENT TEST.
ASSEMBLY LOAD CASE.
ENDURANCE TEST.

NOW A DAYS ALUMINIUM HAVE ALSO BEEN USED FOR BACK DOORS:--

DIFFERANCE BETWEEN ALUMINIUM AND STEEL PARTS

ALUMINIUM	STEEL
* Parts are Casted	* Parts are stamped
* Reinforcements can be neglected	* Reinforcements are neccessary
* Local thickness can be varied	* Has only uniform thickness
* Light in weight	* Heavy in weight
* Used in high end cars	*Used in both high and low end cars
* Cost is more	* Cost is less

So by using of aluminium we can reduce the number of parts and assembly involvement. and it is castly material.

DESIGN CONCIDERATION

Rear visibility criteria
Luggage volume
Crash Analysis
Bend Test
Dent Test
Torsion Test
Endurance Test
Abuse Case
Assembly Load Case
Look After Strength
Joining Techniques
Creating Reinforcements

DESIGN INTENSION:--

The intenstion of the project is to design a Body In White Back Door of the vehicle considering the engineering standards and manufacturing requirements which satisfies the Deep Drawing process.

DESIGN METHODOLOGY:--

INSPECTION:--

First check the given CLASS A surface by Method of Examine Geometry/ sew, If there are Gaps/ Issue with the given CLASS A surface try to fix it.

TOOLING DIRECTION:--

Before starting to design the inner panel of the back door the tooling direction for Deep Drawing purpose should be created.
Then the styling surface needs to be checked and analyzed since it might have irregularities, hence it must be fixed first.
Then the back door was designed using the approach.

BACK DOOR INNER PANNEL:--

After creating the tooling direction the design of the inner panel will begin where we will first develop an effective sealing flange by checking all the boundaries and by following the shape of the inner panel design.
By creating multiple flanges and by using surface modeling techniques the concept design of the inner panel was created.
The embosses were created in ‘V-Shape or Y-Shape’ so that if the vehicle undergoes the crash then the force dissipates over it which reduces the damage transferred to the trunk space.

After the concept of the inner panel is developed, then the child components like a hinge, latch, gas-stay locations and their reinforcements must be designed. Which complete the overall design of the tailgate.

MASTIC /HEMMING GLUE:--

The mastic sealant is used to fix the inner panel with the outer panel which increases the NVH factor and stiffness of the back door.

HINGE AND GAS STAY MOUNTING:--

The circle denotes the hinge emboss which was created using the datum plane and emboss feature in NX. It was also designed in a way that the emboss should have a flat surface for assembling the hinges using it.
The circle denotes the gas stay emboss which was created using the surface of the connecting flange.

LATCH AND STRIKER MOUNTING:--

The Latch and Striker emboss were designed by creating a trajectory which follows the opening and closing of the back door with respect to the hinge axis.

TRAJECTORY:--

To creat Latch and Striker emboss so we have to design by creating a trajectory which follows the opening and closing of the back door with respect to the hinge axis.

WIPPER MOTOR MOUNTING:--

The Wipper Mounting emboss were designed by creating a emboss which was created using the datum plane and emboss feature in NX to attach the wipper motor

Desingin the reinforcements:--

HINGE REINFORCEMENT
GAS STAY REINFORCEMENT
WIPER MOTOR REINFORCEMENT
LATCH REINFORCEMENT

All the reinforcements were created using the same method, first the linked body was created separately for each with the help of extract geometry and then the required portion was trimmed out and then thickened it.

BACK DOOR OUTER PANNEL:--

The Back Door outer panel was created using the styling surface.
The outer panel was designed as two separate parts named as outer panel upper and outer panel lower.
After designing the outer panel the Hemming was created by offsetting the surface with the help of face blend and swept surface.

RELIFES:--

Providing Relifes at the corners Relief helps to control sheet metal material behavior and to prevent unwanted deformation during unbend operations and also helps to reduce the number of passes in hemming.

HEMMING:--

Hemming is a sheet metal forming process in which sheets are joined by bending it to 180°. Automotive body panels and automotive parts such as deck-lids, trunk-lids, doors, hoods and tailgates are formed by hemming process. In this process, usually a sheet is bent with the help of inner sheet in three different stages