Method and device for manufacturing arc-shaped coil spring

An arc-shaped coil spring manufacturing method as a method for manufacturing a coil spring with a curvature from a straight cylindrical coil spring, comprising:

• a first clamp step of fixing the straight cylindrical coil spring;
• an end portion detection step of detecting an end portion;
• a rotation angle position determination step;
• a first pitch feeding step;
• a first pressing member insertion step;
• an insertion direction conversion step of converting an insertion direction with respect to the coil spring;
• a second pitch feeding step;
• and
• a second pressing member insertion step,
• wherein the insertion direction conversion step is a step of
• fixing, at the second clamp step, an opposite end portion of the back end portion at the first pressing member insertion step, and
• deactivating the first clamp step to reverse a feeding direction of a pressing member,
• the first pressing member insertion step and the second pressing member insertion step are steps of continuously repeating operation of pushing down the pressing member to an inter-pitch from above, thereby deforming the straight cylindrical coil spring into the arc-shaped coil spring with the curvature, and
• for a deformation amount,
• operation of the pressing member to a vicinity of the coil spring,
• operation of the pressing member from a position after the operation until the pressing member contacts the coil spring,
• operation of holding push-down or repeating push-down at least one or more times after contact after the operation, and
• operation of pulling out the pressing member are each controlled to proper speeds such that shaping into a shape with an optional curvature is performed.