| 摘要 |
PURPOSE:To manufacture a high quality heater with little breakage and distortion at the coil portion and free from such defects as insufficient bent at the leg portion, by bending a heater material mounted on a die vertually into a U-shape, then by screwing down the mandrel to form the coil portion, and further by lowering the mandrel. CONSTITUTION:A predetermined length of a heater material 31 is mounted on the die 13, the center portion of the heater material 31 being inserted into the groove 17 provided in the mandrel 16, and the same is lowered until the heater material 31 is shaped into vertually a U-shape along the axis of the sleeve 15. Then, with the sleeve 15 kept at it is, the mandrel 16 is screwed down at a predetermined pitch to provide the coil portion 32 having a predetermined number of turns. And then the mandrel 16 and the sleeve 15 together are lowered, whereby the heater material 31 is subject to squeezing force in the gap between the sleeve 15 and the die 13 and the leg portion 33 is thus shaped. In the described manner, a heater with little breakage and distortion at the coil portion and free from such defects as an insufficient bent at the leg portion can be manufactured. |
