| 摘要 |
PURPOSE:To produce efficiently a barrel-shaped coil spring by compressing beforehand a core body in its axial direction and winding a coil strand thereon. CONSTITUTION:When outer mounting members 3 are pressed from both sides to compress axially a core body 1, respective round steels 2 curve outward and the body 1 has the barrel shape of the diameter increasing gradually from both ends toward the center. The top end of a heated coil strand (b) is fixed to one end of the body 1, and while the body 1 is rotated in one way around the axial center thereof, the strand (b) is moved at a specified speed from one end to the other end of the body 1. The strand (b) is spirally wound at a specified pitch on the outside circumference of the body 1, and a barrel-shaped coil spring (a) of which the coil diameter increases gradually from both ends toward the center is formed. The compressive stress exerted on the members 3 is removed after removing the top end of the strand (b) from the body 1, then the body 1 is reduced in diameter to the original state and the barrel-shaped coil spring (a) is taken out as it is. |
