| 摘要 |
<p>PURPOSE:To reduce the heat penetration depth and to prevent the plastic deformation of a cylindrical material by providing plural boosting capacitor parts and switch parts in a high-frequency power source part, discharging and recharging the capacitor and specifying the shape of the electrode. CONSTITUTION:An electrode 3a is brought into contact with one end of a cylindrical body such as a nut 2, and an electrode 3b is allowed to pierce the inner diameter of the nut 2 and brought into contact with the other end of the nut 2. A high-frequency power source circuit 4 is actuated to impress a high-frequency power on the nut 2 from the electrodes 3a and 36. Each semiconductor switch circuit 7 is controlled by a switch control circuit 8, and plural boosting capacitor parts 5 are successively discharged and then charged. After the unit 5-10 is discharged, the unit 5-1 is discharged, and the process is repeated. As a result, a voltage is alternately impressed on a couple of input taps of a matching transformer 9, and a high-frequency output is generated on the secondary side of the transformer 9. After the discharge is carried out in a specified cycle, the discharge is stopped by a control circuit 8, and the work is replaced. The power is concentrated and distributed only on the inner surface of the nut 2, and the surface alone is effectively heated.</p> |
