Challenge

Design of backdoor

VVikash Rai18 Mar 2023

Report On Back Door Design.

Design Methodology Of Back Door of a Car:

The back door of car is also called tail gate. It is mainly made from Either aluminium or steel. Now a days carbon fiber is also used in high end premium cars as it is 5 timer lighter and 3 times stronger than steel, but its cost is much much higher as compared to other two available materials i.e Aluminium and Steel. So the choice of materials mainly depends on budget.

Back Door is mainly consist of two parts namely "Outer Pannel" and "Inner pannel". However in some cases for easy assembly and construction Outer pannel itself split into two parts-Outer Upper Part and Outer Lower Part. But Inner Pannel should be made from a single piece of sheet.

While designing the inner pannel there should be space for mountings such as Hinge Reinforcement (Left + Right), Gasstay Reinforcement (Left + Right ), Wiper-motor Reinforcement and Stricker Reinforcement . It is very immortant to use reinforcement at mountings as to increase the strength which looses because of Cut-outs. The thickness of the reinforcement is generally double the thickness of the sheet metal for example if we consider this particular case then sheet thicknesss is 0.75mm and reinforcement is 1.5mm.

Components of Back Door:

Hinge Reinforcement: This is the reinforcement provided for the mounting or fitting of hinges by the help of which back door opens and closes. The axis of rotation of both left and right hinges must be same for smooth opening and closing and space between them should be such that the load is distribuled equally on both the hinges.
Gas-Stay Reinforcement: This reinforcement is provided for fitting of gastay which helps to open the back door automatically. The position of this reinforcement plays a very important role as it desides the opening angle. It should not be away more than 90mm from hinge axis .
Wiper Motor Reinforcement : This reinforcement is provided for wiper motor which placed and fitted inside the back door. There should be sufficient space between outer and inner pannel for easy assembly of wiper motor .
Stricker Reinforcement: This reinforcement is positioned on the lower side of the inner pannel. This mounting should be designed in such a way that stricker movement is always tangent to the circle whose centre coincident with the hinge axis so that proper locking is achieved.

Draft Analysis of Different Components of the Back Door along the tooling dirrection.

1. Back Door Outer Pannel (Upper Side):