The cushioning function of the front bumper spring for GM vehicles is equipped with a spring between the locomotive frame and the wheel, which uses the elasticity of the spring to slow down the bump of the vehicle to some extent.
Due to the limited structure of the product, the GM front bumper springs generally have high strength and good performance. The material is required to guarantee performance in terms of spring strength and toughness. During the processing of multi-strand springs, it should be noted that:
1, the support ring can be selected according to the product requirements of cold and heat and two methods. The heat is not allowed to heat the spring to spark or whitish, and the temperature of the silicon-manganese steel must not exceed 850 °C. The support ring and the effective ring should be in effective contact, and the clearance should not exceed 10% of the nominal gap between the rings.
2. The multi-strand spring characteristic can be determined by the adjustment lead, and the necessary adjustment can be made when the winding distance is obtained. The twisting distance can take 3 to 14 times the diameter of the steel wire, but it is generally 8 to 13 times better. The spring force is also closely related to the free height, the end ring, the outer diameter and the performance of the steel wire. It can be changed by adjusting one or several of them.
3. Springs without support ring and springs with excessively thin wire diameter should not be welded to the spring head, but the end cable should not be loose and should be deburred. For multi-strand springs where the head is to be welded, the length of the welded part shall be less than 3 times the cable diameter (length not greater than 10 mm). The heating length should be less than one turn, and the sanding should be smooth after welding. The welding part should be locally low temperature annealed during gas welding.