Fender Design - Wheel Arch Challenge

Fender Design - Wheel Arch Assessment

Objective:

• To measure the clearance and assess the fender design from the given part file against the European Standards.

Introduction:

Fender: is the curved part which covers and shields the wheel side of the body of a vehicle. There are four fenders in a car, one for each wheel. Its major purpose is to prevent the road debris thrown by the rotating tyre either inwards into the vehicle body or outwards to the surroundings causing damage. It also acts as a shield from the rotating tyre whenever there is a collision with a pedestrian or other vehicles.

Wheel Arch: is a component attached to the fender whenever the wheel of a car exceeds the fender coverage area. The requirement of the wheel arch is decided after assessing the fender design against some standards.

The design regulations for any component vary with region. Similarly, there are various regulations for the Fender Wheel Arch area as below:

1. Japan Requirements:

Measure the clearance L of the tire, hub, cap & 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' shall be more than 5mm at a line 30° forward and 50° rearward from the central vertical axis of the wheel.

2. European Requirements:

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

US Requirement:

Measure the clearance L values on all positions from -100° to 100° and produce clearance check chart to validate
Clearance must be greater than 5mm in all the positions
Wheel guard requirement: The value of 'a' shall be more than 5mm at a line 30° forward and 50° rearward from the central vertical axis of the wheel.

Assessment:

The following steps are followed in assessing the given fender file against European standards:

1. The given surface data is categorized and relevant surfaces are joined to distinguish between the fender and the wheel.
   
2. A point is created at the centre of the outermost face of the wheel surface.
   
3. A plane is created taking the point as a reference.
   
4. A positioned sketch is created taking the plane and the point as references. Here, we follow he European regulations and created the sketch as shown below.
   
5. Create another plane at the same point but perpendicular to the previous plane
   
6. Create a positioned sketch on the new plane and create vertical lines coincident with the end points of the previous sketch as shown below
   

Observations:

The following observations are made from the sketches created above for the Fender against the European design regulations for the Wheel Arch:

Section	SB-SB	SA-SA	SC-SC	SD-SD	SE-SE
Required Clearance (in mm)	10	10	10	10	10
Obtained Clearance (in mm)	10	9.949	-0.114	-2.888	-5.997
Result	Cleared and valid	Cleared but invalid	Intersects and invalid	Intersects and invalid	Intersects and invalid
Wheel Arch requirement (length in mm)	not required	0.051	10.114	12.888	15.997

Wheel Guard Requirement:

Section	SB-SB (30° forward)	SC-SC (50° rearward)
Required Clearance (in mm)	> 5	>5
Observed Clearance (in mm)	43.642	38.36
Result	Wheel Guard is required

Conclusion:

• Hence, it can be stated that the given fender design does not completely clear the European standards.
• As a result of which, Wheel Arch is to be provided with the given dimensions at the respected sections.
• Wheel Guard is also required because of the high clearance of value 'a' at the sections 30° forward and 50° rearward between the wheel and the fender.