Disclosed are a control method and a device for a cutter shaped by a helical spring, which comprises two cutter position controlling devices (20) connected to two spring outer diameter cutters (10) respectively and comprises a cutter lifting device (30). The two cutter position controlling devices (20) are arranged in the same mounting plane (40). The cutter position-controlling device (20) controls an amount of displacement of the stretching and retracting of the two spring outer diameter cutters (10). The amount of displacement of the spring outer diameter cutters (10) and the amount of up and down movement of the mounting plane (40) are controlled simultaneously by a motor (50). By applying the concept of relative coordinates, the requirements of control can be simplified from two two-dimensional control movements to three single-axis linear movements by using the centre (P3) of a spring coil as the origin of the coordinates for the movement of the spring outer diameter cutter. In the case that the distances of linear movement on the three axes are identical or at a fixed ratio, the advantage of reducing the number of motors is achieved.

A coiling machine includes a material guide, first pin, second pin, pitch tool, cutting tool, heating device, temperature sensor, and controller. A material is bent between the first pin and the second pin to form an arc part between the first pin and the second pin. The controller select control data corresponding to the temperature of the material from a plurality of control data corresponding to a processing temperature. Then, the positions of the first pin and the second pin are controlled such that a radius of curvature of the arc part increases when the temperature of the material increases, and the position of the cutting tool is controlled such that a gap between the center of curvature of the arc part and the cutting tool increases.

A coiling machine includes a material guide, first pin, second pin, pitch tool, cutting tool, heating device, temperature sensor, and controller. A material is bent between the first pin and the second pin to form an arc part between the first pin and the second pin. The controller select control data corresponding to the temperature of the material from a plurality of control data corresponding to a processing temperature. Then, the positions of the first pin and the second pin are controlled such that a radius of curvature of the arc part increases when the temperature of the material increases, and the position of the cutting tool is controlled such that a gap between the center of curvature of the arc part and the cutting tool increases.

The present invention relates to a hot coiling machine, and an object of the invention is to provide a hot coiling machine that produces coil springs having various coil shapes and diameters from a heated wire without a mandrel. The present invention provides a hot coiling machine including: a center roll rotating by a drive unit; a feeding roll disposed near the center roll and facing an external surface of the center roll, the center roll being configured to move by a first positioning unit and being rotated by a drive unit thus moving a wire together with the center roll; a forming roll for forming the wire into a coil shape; and a pitch control unit disposed near the forming roll to come into contact with the coiled wire and pushing the coiled wire to provide the coiled wire with a desired pitch.

The present invention relates to a hot coiling machine, and an object of the invention is to provide a hot coiling machine that produces coil springs having various coil shapes and diameters from a heated wire without a mandrel. The present invention provides a hot coiling machine including: a center roll rotating by a drive unit; a feeding roll disposed near the center roll and facing an external surface of the center roll, the center roll being configured to move by a first positioning unit and being rotated by a drive unit thus moving a wire together with the center roll; a forming roll for forming the wire into a coil shape; and a pitch control unit disposed near the forming roll to come into contact with the coiled wire and pushing the coiled wire to provide the coiled wire with a desired pitch.

A coiling machine includes feed rollers for moving a wire, a wire guide, a first forming roller, a second forming roller, a pitch tool, a cutting mechanism, and a support mechanism for supporting the wire. The cutting mechanism includes a cutting rotor. The wire coming out of the wire guide is formed into a helical shape by the first forming roller, the second forming roller and the pitch tool. After one coil spring of a predetermined length is formed, the wire is cut by moving the cutting rotor in the radial direction of the wire. The cutting rotor cuts the wire supported by the support mechanism in the radial direction of the wire between the second forming roller and the pitch tool.

A coiling machine includes feed rollers for moving a wire, a wire guide, a first forming roller, a second forming roller, a pitch tool, a cutting mechanism, and a support mechanism for supporting the wire. The cutting mechanism includes a cutting rotor. The wire coming out of the wire guide is formed into a helical shape by the first forming roller, the second forming roller and the pitch tool. After one coil spring of a predetermined length is formed, the wire is cut by moving the cutting rotor in the radial direction of the wire. The cutting rotor cuts the wire supported by the support mechanism in the radial direction of the wire between the second forming roller and the pitch tool.

A spring forming apparatus is shown generally at 200, in which metal wire 220 is fed from a supply (not shown) by feed rollers 230, via irregularity-effecting rollers 240 to a forming station 250. The forming station comprises a first deflector 260 and a second deflector 270. When the spring S is complete, it separates automatically from the rest of the wire 220 due to the presence of an irregularity 280, without the need for a cutter device.

A spring forming apparatus is shown generally at 200, in which metal wire 220 is fed from a supply (not shown) by feed rollers 230, via irregularity-effecting rollers 240 to a forming station 250. The forming station comprises a first deflector 260 and a second deflector 270. When the spring S is complete, it separates automatically from the rest of the wire 220 due to the presence of an irregularity 280, without the need for a cutter device.

A compression coil spring includes a steel wire material containing, hereinafter in weight %, 0.5 to 0.7% of C, 1.2 to 3.0% of Si, 0.3 to 1.2% of Mn, 0.5 to 1.9% of Cr and 0.05 to 0.5% of V as necessary components, one or more kinds selected from not more than 1.5% of Ni, not more than 1.5% of Mo and not more than 0.5% of W as freely selected components, and iron and inevitable impurities as the remainder; the C-condensed layer which exceeds the average concentration of C contained in the steel wire material exists at a surface layer part, and the thickness of the C-condensed layer is within 0.01 to 0.05 mm along the entire circumference of the steel wire material.