Fender Design - Wheel Arch Challenge

OBJECTIVE: To calculate the wheel arch clearance at required points and check whether the car passes the European Standards.

INTRODUCTION

FENDER:

Fender is a BiW component which is basically a sheet metal frame that is mounted over the wheels of the automobile, its primary function is to prevent sand, mud, stones, liquid and other road spray from being thrown into the air or enigine compartment.

WHEEL ARCH:

The wheel arch is an integrated part of a fender assembly. It is a semi-circular part which is positioned above the wheel of a vehicle. In some countries, it is also called as an inner fender.

The most commonly used wheel well are of plastic material. In previous times inner fender was made out of sheet metal. If the vehicle with metal inner fender is used there are high chances of corrosion and rusting because this part mostly comes in contact with moisture and dirt, this is the reason why wheel arch made of plastics are preferred now a days.

The design of wheel arch should be such that it should enclose the tyre in such a manner so that it could prevent road sprays like mud, waters and stones from getting inside the engine compartment and also protects the pedesterian from stones hurled by the car tyres.

WHEEL-ARCH GAP REGULATIONS

For the vehicle to has its use permit in different countries the wheel arch of fender must be complaint with the standards and regulations set by different countries.

Japanese Regulations:

• Measure clearance L of the tyre, hub, cap and fender in three different positions within area K and produce clearance check chart to validate.
• Clearance must be greater than 5mm in all three positions.
• Wheel guard requirement: The value of a shall be more than at a line 30deg forward and 50deg rearward from the central vertical axis of the wheel.

European Regulations:

• Meausre clearance L at sections SA-SA, SB-SB, SC-SC, SD-SD and SE-SE and produce clearance check chart to validate.
• At all five sections the clearance value L should be greater than 10mm to satisfy the european standards.
• Wheel Gaurd requirement: The value of 'a' shall be more than 5mm at a line 30deg forward and 50deg rearward from the central vertical axis from the axis of wheel.

US Regulation Requirements:

• Make clearance check details on all positions from -100deg to 100deg and make the clearance check table.
• All values should be geater than 5mm to satisfy the regulations.
• The value of 'a' shall be more than 5mm at a line 30deg forward and 50deg rearward from the central vertical axis of the axis of wheel.

WHEEL-ARCH GAP CALCULATION

• Here we are going to calculate the value of wheel-arch gap value and we are going to validate that data according to the european regultaions.
• First we'll create a sketch on a plane which is parallel to the wheel rim or side face and we'll create lines as per the european regulations as shown in the figure below.
• After creating the sketch we'll project this sketch on the outermost face of the wheel and on the fender surface having the periphery or boundary of the fender near the wheel. By doing this we'll get the required points on the peripheral egdes of Arch and Wheel.
• Finally we'll measure the distance between the corresponding points of the wheel and arch and we'll consider the distance along the z cordinate axis as the clearance can be measured along the z direction only.

CHECK LIST: