Challenge

Fender Design Challenge

HHarish Ram31 Aug 2021

FENDER DESIGN

AIM:

To design a front fender with appropriate Drip Area Mounting,A pillar Mounting,Bumper Mounting,Baffle mounting area and Sill Mounting area from the sytling surface received as input.

FENDER:

Fender is a part of an automobile which comes just above the wheel connected to the hood,bumper,A pillar and sill.Moreover it is a house for the wheels.It is made of either steel or Aluminum.Steel is a good absorbant when it comes to impact whereas using aluminum reduces cost in producing BIW(both material has their pros and cons).In a car we have front fender and back fender. Back fender is not produced seperately as it comes along with the body.Fender has different tooling directions and it is a critical component like the hood so it is not given outside the OEM's to design it as they improvise it within their plant. The purpose of a fender is to prevent the wheels throwing mud,rock or other unwanted debris to the engine compartment,in that way the compartment is protected from unwanted damage.It also prevents the chipping of stones from the road to the pedestrians or to the other vehicles.All vehicled must have a fender abiding the road regulations.

We have two types of Fender:

Full bumper type

Half bumper type

Behind the times we used to have full bumper type in automobiles but as the days passed engineers improvised it to a half bumper type(present time) by improving its efficiency and also cutting the cost drastically. It is said that we can use a single blank to create two half bumper fender whereas we can create only one full bumper fender with it.As a matter of fact we are also reducing the scrap.

Mounting of a Fender:

It is fixed with other commodity using fasteners.Fasteners will be present on the other side and only visible when the hood is open so it will not be affecting the car aesthetically.

Some cars will have body side mounting and some will not .It varies from car to car.

Mounting Areas of a Fender:

We have 5 essential mounting areas when it comes to designing of a fender.

Drip Area:

Drip Area is where the fender is attached to the engine compartment.It is the important mounting region.A lot of design consideration is taken before designing drip area such as
From the front side of fender we have to maintain a distance of 150mm for front lamp mounting
From the rear side we need to maintain a min distance of 200mm for the cowl mounting where the wiper motor sits.If the cowl area is less we can go below 200mm
Drip area's total length must be 40mm or below to avoid springback effect
The distance of the edge of the fender area to engine compartment must be atleast 10mm or more in order to prevent unnecessary damage.
The distance between the drip area mouting region to the hood(in open condition)must be atleast of 200mm for the tool workablity.
The distance from the tip of the fender to the side reference line must be 47.5 - 50mm,if it is more or less we need to reduce/increase the fender's region or hood's region respectively. This is done for pedestrian safety(WAD).

The above values are determined from the parent car or through benchmarking.

A Pillar Mounting:

This area of a fender is connected to the A pillar of the car just beside the cowl area.

Bumper Mounting:

This part of a fender is connected to the bumper of the car. Prior communication is held with the bumper colleageus to calculate the exact bumper mounting area.

Sill Mounting Area:

This area comes under the car where the sill area of the car is mounted with the fender.

Baffle Pad Mounting:

Baffle is an important part where it plays a vital role in improvising a car's NVH.It is a plastic part which is placed exactly on the wheel arch area.

INPUT:

Styling surface pf the fender is given as the input along with the master section of the drip area.

Design Approach:

First and foremost when we receive the styling surface of a fender we need to check for the wheel arch whether it passes the specific country regulations. Regulation changes from country to country.If the company wants the car to be selled in all countries, we suppose to take one country regulations which compromises other countries regulations.Thus our car abides all countries regulation.

And following it the drip area is created by the considerations aforementioned

Drip Area:

As said it is an important mounting area. It is designed by the given master section. Ribs are given to strengthen the component and at the end a bead is given to make the sheet more rigid so it will not wither.

And also there is an important consideration that when creating mounting holes, the area around the hole must be flat i.e. if the radius is 2mm then atleast 2mm around the hole must be flat to avoid hassle during mounting.

A Pillar Mounting: