| 摘要 |
PURPOSE:To improve productivity by performing the stage of coiling a blank material synchronously with the stages of cutting and grinding and finishing end surfaces. CONSTITUTION:To coil a blank material into a coil spring of prescribed length size, end surfaces of the material are ground and finished while cut at a high speed by a cutting grindstone which rotates at a high speed synchronously with the stage of coiling. Then, low-temperature annealing is performed upon occasion. Thus, the grinding and finishing of the end surface are performed simultaneously with the cutting, so the end surfaces are excellent and the stage of grinding the end surface after the low-temperature annealing is unnecesary. Further, successive coiling prevents the crushing of the wire to reduce variance, thereby improving productivity. |
