| 摘要 |
PURPOSE:To contrl automatically quality of a coil spring by applying repeatedly load on a heat-treated blank material several times, measuring the spring load, comparing the same with a set value and increasing or decreasing the spring load. CONSTITUTION:When a motor 6 runs, the 2nd roller 13 rotates to deliver a blank material 1 from a blank material guide 14. The material 1 is bent to a semicircular shape along a mandrel 22 by means of a bending die 23. When a cam 16 rotates, the 1st lever 26 descends and the 2nd lever 28 descends as well thereby moving a screw 29 toward the direction of the material 1. The pitch feed pawl 21 of a pitch feed bar 19 hooks the material 1 and moves the material by a specified stroke, by which the pitch of the coiled blank material is formed. When the cam 16 makes one turn, one coiled blank material is formed. A cutting blade 30 moves in a U direction and cuts the blank material. If the result obtd. by comparison in a deciding stage does not satisfy a reference value, the pulse necessary for correction is applied to a pulse motor 35, then the screw 29 is screwed down or unscrewed to and from a lever 27 by the rotation of an output shaft 37. The initial position of the pawl 21 is thus changed and the spring load is changed. |
