AUTOMOTIVE BACKDOOR DESIGN
PROJECT TITTLE: Design of backdoor
OBJECTIVE: To design an automotive backdoor and provide the necessary reinforcements and embosses.
INTRODUCTION: Backdoor of a car is also called tailgate. Generally a backdoor consists of inner panel, outer panel, different reinforcements, hinges, latch and striker etc. Car backdoor is mainly made of steel or aluminum based on the budget of a car. Aluminum backdoor improves the strength of the parts and also reduces the weight. As the aluminum parts are casted therefore we can vary the thickness of the parts hence we can avoid the reinforcements. While for steel parts we cannot vary thickness as the parts are stamped, therefore we have to provide reinforcements hence the weight of the backdoor increases.
ON THE BASIS OF HOW DOORS OPEN TAILGATE IS OF FIVE TYPES
DESIGN CONSIDERATION:
- Rear visibility criteria
- Suitable embosses
- Required cutouts
- Different reinforcements
- Hinge axis positioning and latch and striker trajectory
- Luggage area space
- Joining techniques followed like hemming, spot welding etc.
REAR VISIBLITY CRITERIA:
While designing the inner and outer upper panel of a backdoor ,the rear visibility criteria plays a major role because the cutout in the inner and outer panel is the deciding factor that how much area is visible through the backdoor wind shield glass.
EMBOSS PATTERN:
Embosses are being provided in a structure to increase the strength of a part. In backdoor inner panel design Y and V shape embosses are given because in case of collision these embosses will dissipate the forces away from the car.
REQUIRED CUTOUT:
Many cutouts have been provided in the inner panel for accommodating wiper motor , latch and striker motor, other necessary components etc.
Different reinforcements:
Reinforcements are provided in a design to compensate for loss of strength in a region or area due load acting there.in case of load acts in form of hinges, gas stay, latch and striker and wiper motor. Therefore required reinforcements are provided.
Hinge axis positioning and latch and striker trajectory
Position of hinges and latch and striker plays a vital role in a tailgate design , because the position of hinges will decide the trajectory of the backdoor and according to the position of the hinge axis we have to position the striker in such a way that striker should always be perpendicular to trajectory.
LUGGAGE AREA SPACE
In this case the value of ‘t’ will decide the luggage area. Larger is the value of ‘t’ lesser will be the luggage area
JOINING PROCESS:
- HEMMING: Hemming is the process in which the edge is rolled flush to itself, while a seam joins the edges of two materials.
- MASTIC SELANT: Mastic sealants are made up of hard rubber, they are used to join the inner panel and the outer panel.it improves the NVH. Mastic sealant are preferred over spot welding because it will be improve the aesthetics of the car.
HINGES: A hinge is a type of joint that attaches two things together while allowing for limited movement.
DIFFERENCE BETWEEN ALUMINIUM AND STEEL BACKDOOR
| ALUMINIUM | STEEL |
| Parts are casted. | Parts are stamped. |
| Reinforcement can be neglected | Reinforcement is neccesary |
| Local thickness can be varied | Thickness can't be varied. |
| Lighter in weight and less no. of parts | Heavier in weight and more no. of parts |
| High cost | Low cost |
DRAFT ANALYSIS: It is a tool that allows the user to 'see' whether the part they are designing can be removed from the tool being used to make it .We always need to provide positive draft angle.
CONCLUSION: The backdoor was designed in Siemen’s NX and all the necessary reinforcement have been provided.
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