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Exam 2-A |
Automotive Design |
1st semester 1428- 1429 |
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Student Name: .Student No |
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1) a- Define the following: |
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a- Clutch constant pressure approach:
b- Spring rate:
c- Spring buckling:
b- What are the functions of the following automobile clutch parts:
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Part |
Functions |
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Cover bolts |
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Clutch cover |
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Elastic Strips (Strap) |
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c- What are the advantages of the automobile clutch diaphragm springs over coil
springs?
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2) A single plate friction clutch has to match with an engine which has a maximum torque of 180 Nm. ASSUME UNIFOEM (CONSTANT) WEAR.
A) If the bearing pressure (pmax) of the frictional material is 0.179 MPa, ri = 80 mm, and m= 0.4, Find the value of outer diameter ro
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B) If the shear stress in the splines (ts) is 50.52 MPa , D = 20 mm, d = 18 mm, L = 25 mm, b = 1 mm, Find the number of splines (n) |
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C) If F = 1100 N, n strip = 2 , t = 0.5 mm, B = 16 mm, d = 6 mm, L = 60 mm, S = 8 mm i- Find shear stress (ts) in the metal strip
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ii- Choose a suitable material for the strip taking a safety factor (SF) of 6. |
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3) A- A car has a mass of 1200 kg, and the front axle load is 60% of car load. If the coil springs on the front axle are supposed to have an equal stiffness and equal deflection (d) of 200 mm when fully loaded. Find the spring rate (stiffness) of the front springs (k).
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B- When a load (P) of 3000 N is applied on a spring, the shear stress in the spring due to torsion only (tt) is found to be 340 MPa. The spring has a mean diameter (D) of 150 mm.
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i- Find the minimum spring wire diameter (d) due to torsion only. ii- Find the torsion stress (tmax), taking into consideration both
direct shear and wire curvature, where
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