Fender Design - Wheel Arch Challenge

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 the fender should be such that it must shield wheels and protect both passengers compartment and pedestarians from the projection of watr, mud and stones.The wheel arch area of the fender is usually designed as a cover or shield over the tyre along its perimeter to stop any debris or stones ,dirt,sand,snow,etc,from getting thrown into the vehicle or the BIW area as well as outside the vehicle and onto other vehicles or pedestarians on the road.For the vehicle to has its permit in different countries,the wheel arch of fenders must be compliant with the standards and regulations set by respective countries.

Given part file of Wheel Arch:

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Types of Fender Wheel arch Regulations and standards:

Japan Regulation:

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

Europen Regulation:

• The important parameter which is considered in the designing of wheel arch or wheel is the clearance between wheel and fender during the vehicle bump conditions.
• Requirements have been proposed by vehicle and road safety community to the minimum requirement of wheel arc distance
  from the wheel for safety.
  Rules –
  1. Measure of CL L is done on sections SA, SB , SC, SD, SE.
  2. At all sections the value of CL L should be greater that 10mm.
  3. Wheel guard requirement -: The value of a shall be more that 5mm at 30 Deg forward and 50 Deg rearward from the central axis of wheel.

US Regulation:

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

Calculation of wheel arch area according to European Regulations

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 outermost face of the wheel
• The sketch is created on the new Datum Plane
• A Horizontal line is drawn across the centre of the wheel
• A perpendicular line SA is dropped at the centre of the wheel
• Two lines SB and SC are created at 30° forward of SA and 50° rearward of SA respectively
• A point is created 150mm vertically above the centre line
• A line SE is drawn from the wheel centre and passes from the point created
• Another line SD is drawn from the centre of the wheel and in the middle of lines SC and SE

Sketch

A.Obtaining the values of clearance "L"

i)Measuring "L" for the given wheel and fender at SB:

The value of "L" at SB=10.00mm

ii)Measuring "L" for the given wheel and fender at SA:

The value of "L" at SA=9.9489mm

iii)Measuring "L" cor the given wheel and fender at SC:

The value of "L" at SC=0.113670mm

iv)Measuring "L" for the given wheel and fender at SD:

The value of "L" at SD=2.8787mm

v)Measuring "L" for the given wheel and fender at SE:

The values of "L" at SE=5.9755mm

B.Measuring the clearance vlaue'a' for Wheel Guard Requirement

i)Finding the values of "a" at line 30 deg forward from center vertical axis of the wheel.

The value of "a" at line 30 deg forward from center vertical axis of the wheel =43.6263mm

ii)Finding the value of "a" at line 50 deg rearward from centre vertical axis of the wheel.

The value of "a" at line 50 deg rearward from centre vertical axis of the wheel=38.3597 mm

Conclusion:

From the above results obtained, we can conclude that the given fender doesn't pass the European Standards for Wheel Arch Area.As the minimum clearance L between the Fennder Wheel Arch and Wheel for vehicle and pedestrian safety is 10mm and this design does not meet the requirement.