The role of the pressure disc spring is to use its tension to press the clutch disc and clutch plate tightly on the split wheel so that the engine’s power is reliably transferred to the drive train. The quality requirements of the pressure plate spring are as follows:
1) Material: pressure disc spring material for 65Mn wire or I, II group carbon spring spring wire.
2) Hardness: quenched, tempered cold spring, hardness value should be in the range of 44-52HRC, in special cases its hardness value can be expanded to 55HRC.
3) Appearance quality requirements: the surface quality of the finished spring productshould be smooth, no cracks, oxidation skin, rust and other defects. Cold roll springs do not allow individual indentations, pits and scratches that extend beyond half of the material diameter tolerance.
a. The roughness of the spring end face should be not less than 12.5?m.
b. The compression spring support ring grinding flat part of both ends and tightly grinding is not less than 3/4 of the circumference length, the end thickness is generally not less than the diameter of the wire 1/8. The end head thickness should not be greater than the diameter of the wire 1/3, the width should not be less than 70% of the diameter of the wire.
c. According to the use requirements, can check the spring pitch unevenness. The tolerance is 10% of the spacing, the minimum tolerance value is generally 0.3mm. When the compression spring is compressed to 80% of the total deformation, the spring ring of the normal pitch is not allowed to touch.
d. The vertical tolerance between the two ends of the compression spring and the shaft of the spring is 2.5% of the free height and the minimum tolerance value is 1mm.
e. The straight ness tolerance of the shaft of the compression spring is half the vertical tolerance.