Design of backdoor
DESIGN OF BACKDOOR
OBJECTIVE:
i) From the given styling surface, develop a back door using appropriate design methodologies.
ii) The objective of this project is to design a BIW Back Door of a car with an Inner Panel, Outer Panel, and Reinforcements for the Hinges, Gas stay, Wiper Motor, and Latch by following the engineering standards.
iii) The Inner Panel must be subjected to Draft Analysis for verifying whether it satisfies the Deep Drawing requirements for the tooling direction created in the design.
INTRODUCTION:
The Back Door of a car is the rearmost part of the vehicle which gives access to the trunk space of the vehicle. The rear door also supports the reinforcements and added weights of the Wiper Motor, Gas Stay, Tail Lamp, and Latch and Striker.
The Backdoor/tailgate is one of the closure commodities in BIW sheet metal design. The backdoor has a lot of components inside and is designed to incorporate them easily. It affects the rear visibility and luggage area.
The material used for door manufacturing depends on the budget and performance of the vehicle. Mostly Aluminium and Steel will be used whereas low-budget vehicles use Steel which makes the manufacturing process easy and cost-efficient since it follows the Stamping of Moulds.
COMPONENTS OF THE BACKDOOR :
Outer panel upper
Outer panel Lower
Inner panel
Latch and Striker Reinforcement
Hinge Reinforcement
Gas stay Reinforcement
Wiper motor reinforcement
DESIGN CONSIDERATION :
Rear Visibility
Boot Space and accessibility
Support Structures like hinge and gas stays
Mounts for wiper motor, tail lamps, and other wiring loops.
Manufacturing tecniques
Rear crash regulations and requirements.
Joining techniques like hemming, spot welding etc.
DESIGN OF BACKDOOR OUTER PANEL :
The Outer Panel is the styling surface of the back door. Other components of the backdoor are designed with reference to the outer panel. It acts as the outer cover and deals with the aesthetics of the car.
UPPER PANEL :
The Outer Upper Panel Extracted from a styling surface.
The panel is altered for the required design with the surface tools of NX CAD
The thickness provided for the outer panel is 0.75 mm
Hemming is provided with the corner relief.
LOWER PANEL :
The Outer Upper Panel Extracted from a styling surface.
The panel is altered for the required design with the surface tools of NX CAD
The thickness provided for the outer panel is 0.75 mm
Hemming is provided with the corner relief.
OUTER PANEL OF BACK DOOR :
TOOLING DIRECTION :
First, we need to create the Tooling direction for the Deep drawing operation. It shows that all the operations like embossing is done by considering this vector direction and it will help in manufacturing the part and using for to check the draft analysis.
INNER PANEL :
Car backdoor inner panel is made of either steel or alumminium.Most of the luxuary car's inner panel are made of aluminium because of is properties.But the cost of aluminium is high.
Wiper motor , latch reinforcements,hinge reinforcements and gas stay reinforcements are mounted on the inner panel of the backdoor only.
The embosses in the inner panel helps stiffening the inner panel and act as a local reinforcement
And there should be a gap between the extension and the outter panel is minimum 5mm for mastic sealent.
HEMMING :
Hemming is the metelworking process in which a sheet metal edge is rolled into itself.There must be a 0.2mm gap between outter and inner pannel in both upper and lower side.first roll the panel is bent slinghtly,and in the second roll the shhet matel is rolled even more and in the last roll it completely fits or covered the inner panel
CORNER RELIEF :
During the hemming process, when giving the Corner 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.
DESIGNING THE REINFORCEMENTS:
The thickness provided for all reinforcements is 2 mm.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.
THERE ARE FOUR REINFORCEMENTS AVAILABLE
-
HINGE REINFORCEMENT
-
GAS STAY REINFORCEMENT
-
WIPER MOTOR REINFORCEMENT
-
LATCH REINFORCEMENT
HINGE REINFORCEMENT :
Hinges enable the opening and closing of the back door. One end of the hinge is fixed on the backdoor and the other end on the Roof, on both sides. Hinges can be placed outside or inside the backdoor.
GASSTAY REINFORCEMENTS :
Gas Stay is a device used for supporting the back door in its open position. Gas stay requires no manpower and is engaged into support position automatically as the back door opens. One end of the Gas Stay is fixed on the backdoor and the other end on the Body Side or on the Back door stationary area.
WIPERMOTOR REINFORCEMENTS :
Wiper motor reinforcement is created to mount the wiper motor assembly.
LATCH AND STRIKER REINFORCEMENTS :
The Latch & Striker forms the locking mechanism of the backdoor with the car. Due to regular opening, closing, and over slamming of the backdoor, there is stress developed in the Latch and Striker area.
DRAFT ANALYSIS:
-
The draft analysis will be performed for the tooling direction created at first and checked that the model is suitable for manufacturing.
-
Then to get a complete green portion the necessary changes to the draft angle of the embosses were carried out by optimizing the model.
-
The Draft Analysis command enables us to detect that the part drafted will be easily removed or not.
-
This type of analysis is performed based on color ranges identifying zones on the analyzed element where the deviation from the draft direction at any point, corresponds to specified values.
CONCLUSION :
The back door outer and inner panel were designed with the help of the styling surface along the tooling direction and Draft analysis was performed on the inner panel and All the reinforcements were designed and placed at appropriate positions.