The function of the pressure plate spring is to use its tension to tightly press the clutch pressure plate and the clutch plate on the minute wheel, so that the power of the engine can be reliably transmitted to the drive train. The quality requirements of the pressure plate spring are as follows:
1) Material: The pressure plate spring material is 65Mn steel wire or group I and II carbon spring steel wire.
2) Hardness: The hardness value of the cold coiled spring after quenching and tempering treatment should be in the range of 44-52HRC. Under special circumstances, the hardness value can be expanded to 55HRC.
3) Appearance quality requirements: The surface quality of the finished spring should be smooth, free of defects such as cracks, oxide skin, rust, etc. Cold rolled springs are not allowed to have individual indentations, pits and scratches that exceed half of the material diameter tolerance.
4) Processing density
A. The surface roughness of the spring should not be less than 12.5?m.
b. The flattened part of the compression spring support ring with both ends and tightly ground is not less than 3/4 of the circumference, and the thickness of the end is generally not less than 1/8 of the diameter of the steel wire. The thickness of the head should not be greater than 1/3 of the diameter of the steel wire, and the width should not be less than 70% of the diameter of the steel wire.
c. According to the requirements of use, the unevenness of the spring pitch can be checked. The tolerance is 10% of the spacing, and the minimum tolerance value is generally 0.3mm. When the compression spring is compressed to 80% of the full deformation, the spring with normal pitch The circle is not allowed to touch.
D. The perpendicularity tolerance between the two ends of the compression spring and the spring axis line is 2.5% of the free height, and the minimum tolerance value is 1mm.
E. The straightness tolerance of the compression spring axis line is half of the perpendicularity tolerance.