Front bumper spring for subaru are capable of thermoforming process speed and large spring thermoforming process control. Since there is only the CNC2 shaft hot coil spring machine, the shape control has less three directions, and the precision is poor; and there is no automatic bar material rotation control and adjustment mechanism, so the hot coil spring forming process and the ability are low. Therefore, the degree of precision of the spring and the degree of oxidative decarburization of the surface are also low.
Subaru's front bumper springs generally have high strength and good performance. The material is required to guarantee the final performance in terms of spring strength and toughness. Multi-strand springs are in the process of processing.
Subaru's front bumper spring attention requirements
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 that need to be welded to the head, the length of the welded part should be less than 3 times the cable diameter (maximum length is not more 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.
4. The surface treatment of the spring is generally carried out by phosphating, and other treatments can also be carried out. Where the plating is to be zinc and cadmium, the hydrogen removal treatment shall be carried out after electroplating, and 3% (not less than 3 pieces) shall be pumped after hydrogen removal, and there shall be no break during the retest. The spring should remove surface dirt, salt marks and scales. The method can be sandblasted or gasoline cleaned, but it cannot be pickled.