Design of backdoor

Backdoor:- It is also called as tailgate and it is swinging commodity to open and close. Backdoor is getting assembled at rear side of vehicle with the help of hinge. and below can understand how actually backdoor look like.

Design consideration:-

• Enough bootspace
• Rear visibility
• Material and design strength

Functions of backdoor:-

• It's protect the luggage from any damage or accident from rear side.
• Tail lamp, parking lights, rear camera and etc. got mounted on it.
• It's also increase vehicle strength from rear side for passenger safety.
• Also close the vehicle from rear side to prevent air, dust or any water particle which can goes inside the vehicle.

Types of load test on backdoor:-

1. Bend test
2. Torsion test
3. Dent test
4. Endurance test
5. Abuse test
6. Assemby load test

(1) Bend test:- After manufacturing of backdoor we give external force on different region of backdoor and fixing the border portion of backdoor, At that region it get bend that we need to inspect if it get bend then it has design failure becuase of this bend test.

(2) Torsion test:- At the two opposite corner need to fix and then need to give torsion force to other two opposite corner, Then need to inspect that is there any deformation or getting twisting any area of backdoor.

(3) Dent test:- It is also kind of bend test but in dent test external force with help of punch give on any region and if it get dent and then need to inspect that is it getting to in normal condition ? , If yes then design is safe if not then need to remake the design.

(4) Enurance test:- It is testing the maximum condition of open and closing the backdoor.

(5) Abuse test:- It is test that overslaming or hanging when backdoor is open or half open condition.

(6) Assembly load test:- After the assembly of backdoor need to check the strength of assembly design after applying external forces.

Different parts which is used in backdoor assembly:-

1. Inner backdoor panel
2. Upper outer backdoor panel
3. Lower outer backdoor panel
4. Hinge reinforcement
5. Gas stay reinforcement
6. Motor wiper reinforcement
7. Latch and striker reinforcement

(1) Inner backdoor panel:- This is major part of backdoor which sustain the all external forces. This panel is mounted on inner side of backdoor assembly which is having embosses, holes and reinforcement embosses to increase their strength and reduce weight and other parts like hinge, gas stay, motor wiper and latch striker get mounted on it. It is produced by casted or deep drawing process and for manufacturing it mostly aluminium material is used over steel material.

Tooling direction:- At the tooling direction whole inner panel and embosses are created cause in deep drawing process it can easily to realse after the process, For tooling direction we need to two lines between inner panel between them need to create derived line which we use for as tooling direction and below picture we can under tooling direction.

Sealing flange:- Sealing flange role the major design in inner panel as we see below picture it having border which will get attached to outer panel with the help of hemming process and also need to use sealant glue between them and this sealing flange prevent the water and air particle which can go inside the vehicle.

(2) Upper outer panel:- This is part where every pedestrian can visible from outside and it covers the inner panel, their embosses, all reinforcement and other internal harnesses. also for this outer panel need to give good design corvature for better looking and attractiveness. And this outer panel is devide in two parts which shows in below

1. Upper outer backdoor panel:-

2. Lower outer backdoor panel:-

• Because it's curvature design and for manufacturing process it's need to devide in two parts after manufacturing these two parts need to join these with spot welding and sealant glue like below picture, And also hemming process in doing on these parts for assembled the outer panel and the inner panel. And for hemming process at the all corner need to give corner relief for better joining also corner relief shows at below side.
• On the outer panel there are different parts like, parking lights, break light, sensors, rear camera and etc. got connected.

• Corner relief:-

• Hemming process:- Below picture shows how hemming process look like after joining of outer panel and inner panel, In the hemming process between two sheet metal need to give 0.2mm gap for applying sealant glue for better and long life bonding between them.

• Reinforcements:-

(3) Hinge reinforcement:-

(4) Gas stay reinforcement:-

(5) Motor wiper reinforcement:-

(6) Latch and striker reinforcement:-

• These are all reinforcements which got attached on inner backdoor panel on their reinforcement embosses, These reinforcement thickness is 1.5mm about the application of these reinforcement is give extra strength to other part's assembly area
• when we attached small parts or moving parts to any other big part it's mandatory to give reinforcement for increasing their strength. And below picture how all reinforcement look like after assembly on inner panel.

• Draft analysis:- Draft analysis is inspecting the design from the tooling direction is good or not before deep drawing process for easily release after the process. and below picture shown draft analysis from tooling direction with 7 degree angle.

• And this how backdoor look like after assembly with all parts and reinforcement which shows in below.

Note:- (I cannot make STEP file because of student version of NX, therefore i have attached STL file instead of STEP file.)