Fender Design - Wheel Arch Challenge

TASK 1

FENDER WHEEL ARCH REGULATIONS

FENDER

Fender is the part of an automobile vehicle body that frames a wheel well. Its primary function is to prevent sand, mud, rocks, liquids, and other road spray from being thrown into the air by the rotating tire.

When vehicle is moving, tyres 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 vehicles with a narrow car body that exposes the tire, the fender is an exposed curve over the top of the tire. For wide body vehicles that cover the tire, the fender forms the wheel well surrounding the tire, and is not directly visible from above the car body.

Fender is of two types

1. Full bumper type
2. Half bumper type

FENDER WHEEL ARCH

Wheel arch is the semi-circular part of the fender positioned above the wheel of the vehicle. The design of the wheel arch of fender should be such that it must shield wheels and protect both passengers’ compartment and pedestrians from the projection of water, mud, rocks, sand.

Different countries have different wheel arch regulations in place, and the wheel arch design has to comply with them to be deemed usable in that country. This wheel arch regulations will defer from each country based on their standards and customs.

For avoiding design alternations of the same vehicle to meet the different regulations in the countries, the maximum values of the concerned regulation parameters are taken into consideration for design purpose.

FENDER WHEEL ARCH REGULATIONS

JAPAN REGULATIONS

• Measure clearance L of the tire, 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 the three positions.
• Wheel guard requirement: the value of ‘a’ should be more than 5mm at line 30 degree forward and 50-degree rearwards from the central vertical axis of the wheel.

EUROPEAN REGULATIONS

• The clearance ‘L’ should be measured at sections SA-SA, SB-SB, SC-SC, SD-SD and SE-SE and create clearance check chart to validate.
• At all the five sections the value of L should be greater than 10 mm to satisfy the European regulations.
• Wheel guard requirement: the value of ‘a’ should be more than 5mm at line 30 degree forward and 50-degree rearwards from the central vertical axis of the wheel.

US REGULATIONS

• clearance ‘L’ is to be checked at all positions from 100 degree to 100 degree and create clearance check chart to validate.
• The value of L should be greater than 5 mm to satisfy the regulations.
• Wheel guard requirement: the value of ‘a’ should be more than 5mm at line 30 degree forward and 50 degree rearwards from the central vertical axis of the wheel.

TASK 2

Calculate the wheel arch gap at required points and check whether the car passes the European standard

For calculation of clearance between wheel arch and wheel we have to create a sketch on the outer most face of the wheel. The procedure of which is given below.

• A datum plane is created at the outer face of the wheel.
• A sketch is created on the new datum plane.
• A horizontal and vertical axis is drawn from the centre of the wheel.
• The vertical axis intersection point is labelled as A.
• Similar references are drawn at 30 degrees to the left and 50 degrees to the right and named it as B and C respectively.
• A line of 150mm is drawn perpendicular to the horizontal axis and normal from the normal point on fender which gives point E.
• The midpoint of the arc cut by the sections C and E results in a new section D.
• The value of ‘L” at each section and the value of ‘a’ are found out to determine whether the fender satisfies the European standards using measure distance tool.

Sketch for measurement as per European standard

The clearance values

1. The clearance between SA line and wheel arc is 9.94mm.

2. The clearance between SB line and wheel arc is 10mm.

3. The clearance between SC line and wheel arc is 0.11mm.

4. The clearance between SD line and wheel arc is 2.88mm

5. The clearance between SE line and wheel arc is 5.99mm

RESULTS:

	Required clearance	Actual clearance	Ok/Not ok
SA	10	9.94	NOT OK
SB	10	10	OK
SC	10	0.11	NOT OK
SD	10	2.88	NOT OK
SE	10	5.99	NOT OK

CONCLUSION:

From the above results we can conclude that the fender does not pass the European regulations, as the minimum clearance L between the fender wheel arch and wheel for vehicle and pedestrian safety is 10mm. So, the design of given fender does not meet the requirement.