| 摘要 |
PURPOSE:To effectively attain the plastic deformation of a brittle material by combining compressive thermal stress with compressive stress due to bending. CONSTITUTION:Constant depressing pressure is kept on a point of a heat treated wire rod 10 having arc-like bending with large radius of curvature by rolls 12, 13, 14 each of which has a wire rod passing groove and a spring and the point is inserted into an electrode 16 which can be universally lifted up by a lever against spring tension. The wire rod 10 is contacted with the electrode 16 at a constant depressing pressure and the point of the wire rod 10 is gripped by a chuck 19 attached to one end of a roller chain 18. When switches for a low power voltage and a driving motor are turned on under said condition, a material 10 to be treated travels at a constant speed and simultaneously a part of the material 10 is heated by contact resistance to correct bending. If the rolls 14, 15 are held at fixed positions, large bending stress is generated for a wire rod having large bending and the bending due to the pre-treatment is erased to hold the bending due to the post-treatment highly accurately. |
