Fender Design
Title - Design and Development of a front fender of car,
Objective - To design the fender with all the mounting area with the help of the skin data provided.
Introduction - Fender is the US english term for the part of an automobile that frames a wheel. Its primary purpose is to prevent sand, mud, rocks, liquid and other road spray from being thrown into the air by rotating tire. When vehichle is moving, tires pick up stones and others and hurl them in all directions. Fenders are basically present to prevent any injuries to pedestrians and contain the motion of these particles. Most passenger automobiles have four fenders, one over each wheel. For vehichles with a narrow car body that exposes the tire, the fender is an exposed curve over the top of the tire. For wide body vehichles that cover the tires, the fender forms a wheel well surrounding the tire, and is not directly visible from above the car body.
Wheel wells tend to be much larger than the diameter of the tire because they do not move from the tire suspension and consequently must be large enough to allow the full range ot tire suspension without touching the interior of the wheel well. More elaborate design include fender skirts for enclosing the outside edge of the wheel well and stylised pantoon fenders for exposed fenders
There are two tpes of fenders -
Full Bumber Type
Half Bumper Type
Nowadays we use half bumper type because its helps in scrap management. Also it helps in reducing the weight of the steel inturn helping in improvisinf the performance of the car.
Mounting
Fenders are basically mounted on 5 regions and they are
1.Body
2.A pillar
3.Sill
4.Cowl
5.Drip
Design parameters
Fender Drip Area - Drip is the major and imortant area to be designed which helps to join the fender to the engine compartments. To have a suffecient space for the cowl top and its components we require minimum of 200mm in the rear part of the fender. Similarly in the front end of the fender we will be having the head lamp and its housing so the distance after which we have to design the drip area is 150mm. The first flange of the drip mounting should be 3degrees to help in easy manufacturing. There should be a 35mm-40mm of the flat flange on which there are holes to use the tools while assembling. There should be atleast of 10mm gap between the engine room and fender so that we dont damage any parts while assembling. To avoid spring back effect the middle flange should ne within 40mm-60mm.
Manufacturing Processes
A car Fender bumper is made by a process called reaction injection molding (RIM), which basically consists of making a special polyurethane compound and introducing it into a large fender. RIM is a process that conserves raw materials and reduces costs. It is similar to injection molding except thermosetting polymers are used, which requires a curing reaction to occur within the mold. Common items made via RIM include automotive bumpers, air spoilers, and fenders.
Here are the pictures of the design
