The technological process of helical springs refers to the process of converting spring materials into finished springs, which flow through every process in sequence. Because of the spring material, the spring type and the processing method are different, the technological procedures of the spiral spring are also different. However, their basic technological processes are coil spring heat treatment end processing surface treatment.
Next, introduce several typical processes.
1. manufacturing compressed spiral spring with cold drawn spring steel wire
For the lathe coil spring, after the winding spring process has to be cut off, a spring connected to several springs is separated into a single spring.
Some important springs can add a blank height classification procedure before grinding the face to ensure grinding quality. The grinding process can be divided into two processes: rough grinding and fine Tang, and burrs or chamfering after rough grinding.
2. using cold drawn spring steel wire to make spiral spring
The manufacture of stretched coil spring has a special automatic spring coiling machine abroad. For some typical hook rings, it can be completed once in the coil spring process. However, the machine tool has not been produced in China. The drawing spring hook ring is made by some special moulds, and it is a special working procedure.
It is worth noting that the residual stress in the stress recovery process after the coil spring is eliminated in the process of winding, and the tempering process after the making of the hook and ring is to eliminate the internal stress produced when the hook ring is made. Although these two processes all have the effect of eliminating internal stress, they can not be merged into one process, because the former process of tempering has a "shape" function to ensure the relative position precision of the hook and ring. And the heating temperature of the subsequent tempering process must not be higher than the tempering temperature of the previous one.
Unlike compression springs, tensile springs are usually not subjected to "tensile" treatment. Since pellets are difficult to spray into the inner surface of the spring, shot peening is not carried out.
3. using cold drawn spring steel wire to make torsional spiral spring
Similar to the tensile springs, the manufacture of the torsion spring is also made by a special automatic reed abroad. For some typical twisting arms, it can be completed at the same time in the coil spring process. However, at present, only the straightaway spring coiling machine is used in China, and the torsion arm must be completed with special mould in special process.
At present, there are two typical technological processes for the production of twisting spiral springs at home. One is to set down the material first and then to reel the other other processes, such as the process flow of the double arm spring, and the other is the process similar to the spring, but the spring is the hook ring and the torsion spring is the twist arm.
As the residual stress produced in the coil spring is opposite to the direction of the working stress, the tempering process is often omitted in order to allow these beneficial residual stresses to reduce the peak stress of the working stress. However, tempering treatment is conducive to stabilizing the grain structure of spring materials and reducing the deformation caused by collisions in spring transportation.
Strong torsion treatment is also a procedure for arranging very few special torsion springs.
4. make spring springs with spring steel wire supplied by annealed state.
The alloy spring steel wire supplied by the annealing state is mainly used to make the compressed spiral spring. Its process flow is mainly quenched and tempered after forming, and the spring end needs to be treated by normalizing, and the other processes are basically the same.
The process flow of 5. hot coil large spring
The spring with material diameter greater than 12mm is often called large spring and is usually made by thermoforming. The hot coil spring is basically a compressed spiral spring.
The hot coil spring is a core coil spring. For the coil conical helical compression spring, because of the difficulty of "opening" (winding out pitch) during the rolling process, it has the task of opening the gears in the correction process. In addition, in order to ensure quenching temperature, the calibration process must be accurate and rapid. Otherwise, the quenching must be reheated. In order to improve the fatigue life of hot coil spring, shot peening should be carried out as far as possible.