As engines develop towards high speed and high power, high-load piston rings have also changed from cast iron to steel, and then special steels such as high-alloy stainless steel are used, and oil rings with complex special-shaped cross-sections such as approximate H-shaped cross-sections are used. In addition, strict dimensional accuracy is required, so special-shaped wire processing is particularly important. So, let’s learn about the forming method of special-shaped wire processing!

At present, special-shaped wire processing mostly involves forming a round wire into a rectangular wire and then drawing it. Then, after 3 to 5 repeated operations, it becomes the set shape. In this case, if special steel is used as the piston The material of the ring needs to be annealed multiple times to remove strain during the forming process. Especially in the case of high-alloy steel with special-shaped cross-sections, the number of drawing forming and intermediate annealing increases, resulting in increased costs.

In order to reduce costs, special-shaped wire processing requires increasing the cross-sectional shrinkage rate of one processing, reducing the number of drawing forming, and reducing the number of intermediate annealing. However, in the forming of the above-mentioned non-driven Teke head, it is usually drawn by a winch, etc. Therefore, in order to increase the cross-sectional shrinkage of the Turk head, a larger pulling force is required. In this way, because the force exerted on the wire becomes larger and the wire elongates, the edge cannot be fully filled into the rolling pass only when the wire is elongated in the length direction. Therefore, when forming special-shaped wire with the traditional Teke head roller, In order to increase the filling rate, the cross-sectional shrinkage rate must be reduced, the tension on the wire must be reduced, and the number of forming cannot be reduced.

The purpose of special-shaped wire processing is to provide a forming method and device that can increase the filling rate, reduce the number of intermediate annealings, and form special-shaped wires efficiently and accurately with less forming equipment. In particular, the present invention is applicable to the forming of special-shaped piston ring materials of high-alloy steel with complex cross-sectional shapes, but is not limited to piston rings and can also be applied to the forming of a wide range of special-shaped materials.

In order to reduce the number of forming processes during special-shaped wire processing, it is necessary to increase the primary cross-sectional shrinkage during forming. However, as mentioned above, the current Tex head roller does not have a driving device and performs drawing by rotating the roller by the drawing force of the capstan without driving. Therefore, the drawing force acting on the wire during drawing forming is large. The wire extends along the length direction and fills the cross-section of the roller hole. In addition, when the cross-sectional shrinkage becomes large, the material extends along the length direction under the action of tension. When the processing limit of the material is exceeded, cracks may occur on the surface and breakage may occur.

Special-shaped wire processing has carried out many experiments with the goal of improving the hole filling rate and reducing the number of forming times, and the following results have been obtained. The design of the Turk head drive roller can achieve tension-free wire forming and improve the filling rate close to the edge of H-shaped special profiles. , reduce the number of forming times. Increasing the diameter of the Tex head roller can improve the filling rate of the edge. On the other hand, the non-driven Tex head may easily obtain dimensional accuracy. Other supporting factors must be considered, such as good arrangement to adapt to small batch and multi-variety production, The hole shape has high degree of freedom and easy rigidity.

The above introduction is the forming method of special-shaped wire processing. If you need to know more, you can contact us at any time!