Fender Design - Wheel Arch Challenge

FENDER-WHEEL ARCH

Fender:

Fender is a component of an automobile body that frames as wheel wall, its primary purpose is to prevent sand, rocks and other foreign materials being throw away from rotating tire.

Wheel-Arch:

Wheel arch is a semi-circular part positioned above the wheel of the vehicle, the shaped part of the bodywork of a car that allows the wheel to be accessed, and in the case of front wheels, enables them to be steered.

Wheel-Arch Design:

The wheel arch main design consideration is to provide a minimum clearance between the wheel arch and the outer edge of the wheel and the main purpose of the wheel arch area regulation is that seeing the front fender and tire from the top view, the tire must be inside the fender by a certain distance.

The clearance depends upon the regulations followed, various regulation are

Japanese standard:

• Clearance L of the wheel and fender in three different positions by producing a clearance check chart to validate.
• Clearance must be greater than 5 mm in all the three positions (i.e., at A, B, C from fender curvature)
• Wheel guard requirement: The value of 'a' shall be more than 5 mm at line 30֯ forward and 50֯ rearward from the central vertical axis of the wheel.

European standard:

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

US standard:

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

Examining the wheel-arch considering the European Standards:

As per European regulations the clearance value between the fender and the wheel should be minimum 10 mm at 5 different points. The points are projected points at an angle of 30֯ anticlockwise and 50֯ clockwise to the vertical axis respectively and a point at a vertical distance of 150mm from horizontal axis and an equidistant point from 50֯ point and 150 mm point.

Procedure:

Sketch will be created on the XY plane such that according to European standards we can create points.

1. A point created by a vertical line intersecting the wheel arch area.
2. A point created by a line which is 30֯ anticlockwise direction to the vertical axis and intersecting the wheel arch area.
3. A point created by a line which is 50֯ clockwise direction to the vertical axis and intersecting the wheel arch area.
4. A point created by a line which is passing through a point at 150mm distance from the horizontal axis intersecting the wheel arch area.
5. A point created by a line which is passing through the equidistant point from the points created in 3^rd & 4^th step of the process.

Now the required points can be formed by projecting the each line from the sketch on to the wheel arch area.

Now to check the clearance we need points on the wheel too, for that each line will be extruded in the direction of Z-axis such that it will intersect the wheel area.

Now intersection point can be created from the extruded profiles and the wheel such that we can get the required points which are in brown in colour on the wheel.

Now from the top view of the model we can easily calculate the distance between the projection points created on the wheel arch area and the wheel.

Now the clearance is found using the measure option and the values in the component of Z-axis are the exact values

Points	SA	SB	SC	SD	SE
Clearance (L)	10	9.949	-0.171	-2.941	-6.039

From the above tabulation we can find that according to European standard the clearance value should be greater than 10mm, which in this case no points are following the standard and the modification to be done.