How to Solve the Compression Problem of Coil Springs?
(1) From a practical perspective
In practice, everyone often encounters that the coil spring cannot press the moving object at the set position, that is, the arbitrary size of the coil spring is short. The core reason is that the helical spring is compressed by excessive force to the compression degree or compression degree (if necessary) without being subjected to the original compression treatment. After opening, the coil spring cannot be restored to the original random size operation process. Its shortening is called "raw compression". In general, after 3 to 6 compressions, the size has not been shortened, that is, the coil spring is "precisely positioned". The coil spring is permanently deformed after the original compression.
(2) From a specific work perspective
In a specific job, even if the force experienced by the compression spring exceeds the ductility limit of the raw material, it should be able to maintain its working size. Therefore, the size of the finished coil spring should be equal to the calculated length and original compression of the coil spring, so that the coil spring cannot be in place, which will cause risk stress when the coil spring ring is tightened, which may cause the coil spring marking line to An exception has occurred and is not a substitute for the coil spring identification line. During the heat treatment process of the finished product coil spring, especially during the tempering process, the artifact should be placed in the furnace as horizontally as possible to prevent the coil spring from being shortened due to its own weight effect, resulting in poor operation.
(3) From the angle of insufficient coil spring force
The requirement of insufficient spring force of the coil spring is to cause the necessary coil spring force as much as possible under the specified deformation. If the load is removed, the coil spring will be repaired to an arbitrary size, and the moving member will smoothly move to the set position. But sometimes the coil spring force cannot be fixed.
(4) From the perspective of stretching
During the stretching process, try to get rid of the friction between the ring and the ring, the ring and the mandrel or sleeve, and the friction between the motion pair and the motion pair. Sometimes the sliding friction range is very large (up to ± 50 %), Resulting in insufficient coil spring force. Unable to get rid of the friction and move the components in place, causing the coil spring to work ineffective. Therefore, try to strictly implement the production process standard as far as possible to carry out in-depth each process, such as screening, coil spring molding, flattening of both ends, removal of edges and corners, heat treatment process, correction adjustment, initial pressure treatment, inspection and refueling.
(5) Other angles
In addition, the coil spring force is also related to design factors and raw material selection factors. From the two core calculation methods of the coil spring, namely the deformation formula lambda = 8pd32n / gd4 and the ground stress formula _uu = k8pd2 / pid3, it can be seen that the coil spring force is greatly affected by the diameter of the wire, ring diameter, deformation and number of rings. This is closely related to the characteristics of raw materials, working temperature, load characteristics and ring numbers. Dynamic hazards can cause abnormal coil spring forces and deformation markings.