Fender Design - Wheel Arch Challenge

Wheel Arch gap – Calculation

Aim:

To calculate the wheel arch gap at required points and check whether the car passes the European standard.

Objective:

• Study about the different wheel arch gap standards.
• Draw the lines at the required angle and points for the European standard.
• Measure the distance at each angle and mention given model is passes or fails.

Theory:

Fender:

A fender is a part of an automobile, motorcycle or other vehicle body that frames a wheel well (the fender underside). Its primary purpose is to prevent sand, mud, rocks, liquids and other road spray from being thrown into the air by the rotating tire. Fenders are typically rigid and can be damaged by contact with the road surface.

The main purpose of fenders on cars is that they shield the wheels, and they protect the passenger the pedestrians and the other vehicles from stone, mud, liquid and other debris that can fly in the air because of the speeding rotating wheels while the car is running.

Wheel Arch:

It is a curved part of the fender positioned right above the wheel. The wheel Arch is designed such that it protects both the pedestrian and car cabin from mud, water rocks and other road spray. Different countries have different wheel arch regulations in place, and the wheel arch design must comply with them to be deemed usable in that country.

For avoiding design alterations of the same vehicle to meet the different regulation parameters are taken into consideration for design purpose.

Fender Wheel Arch Regulation:

Japan Regulations:

• The clearance “L” for tire, hub, cap and fender is to be measured within area K and create clearance check chart to validate.
• The value of L should be greater than 5mm at all positions.
• Wheel guard requirement: The value of “a” should be more than 5mm at line 30degree forwards from the central vertical axis of the wheel.

European Regulations:

• The clearance “L” should be measured at section 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 10mm to satisfy the European Regulations.
• Wheel guard requirement: The value of “a” should be more than 5mm at line 30degree forward and 50degree rearwards from the central vertical axis of the wheel.

US Regulation:

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

Calculation of wheel Arch area – European Regulations

For calculation of clearance between wheel Arch and Wheel we must create a sketch on the outer most face of the wheel and the procedure as follows.

From the given part file, we need to open in the NX cad and from the part file they give the fender and the wheel and the wheel. So, now we need to check for the European Regulations standard. Now we need to create the Datum plane at outer most face of the wheel.

After that in that plane we sketch the lines and the given the required angle from the reference of the European standard drawing by using the Rapid dimension.

And using the text give the proper name to the lines and the dimensions are set as per the European standard.

Then we need to measure the distance from the outer most wheel to the outer most wheel arch for that we add some points on the face and the angle line as shown in figure.

And now using the analysis tab in the NX Cad in that click simple distance to measure the required distance as the European standard as shown in figure. From the SB line the clearance distance we measure is 46.13mm and the 50degree SC line the clearance distance is 38.68mm as shown in figure.

Standards:

• "a" should be more than 5mm at line 30degree forward and 50degree.

• "L" should be greater than 10mm.

From the measuring for clearence are given below

for "a" values

SB = 46.13 mm

SC = 38.68 mm

for "L" values

SB-SB

SA-SA

SC-SC

SD-SD

SE-SE

SB-SB = +10 mm

SA-SA = +9.94 mm

SC-SC = -0.11 mm

SD-SD = -2.88 mm

SE-SE = -5.99 mm

And the results are tabulated which is given below

SECTION	L(.10mmm)	Result	a(>5mm)	Result
SA-SA	10	FAIL
SB-SB	9.94	PASS	46.13	PASS
SC-SC	-0.11	FAIL	38.68	PASS
SD-SD	-2.88	FAIL
SE-SE	-5.99	FAIL

Conclusion:

From the abov results we can conclude that the Fender dose not pass the European Regulations as the minimum clearance between the fender arch wheel to the outer most wheel is 10mm and this design dose not meet the this minimum clearance so this fender designe is fail for the European Regulation standard.