| 摘要 |
PURPOSE:To make the productivity high and to lower the cost, by fitting a synthetic resin tube in a preheated and softened state into a bending jig, and resistance-heating the bending jig for a short period of time to a prescribed temperature. CONSTITUTION:After a linear synthetic resin tube 1 with connecting metal devices 2 forcibly fitted into the opposite ends is preheated at about 60 deg.C to be softened, it is fitted ina bending jig 3 while it is twisted a little, with the connecting metal devices 2 being spaced a little away from the opposite ends of the beinding jig 3. Then a prescribed heating electric current is passed from a heating electric power control 5 via terminals 4, 4 to the bending jig 3. As a result, the being jig 3 is heated and can bent the synthetic tube 1 by the resistance heat. In this case, the change in temperature of the bending jig 3 is transmitted incessantly from a temperature sensor 6 to the heating electric power control 5 to keep the temperature at a prescribed temperaturae of 165 deg.C.When a prescribed period of about 1min has passed, the heating electric current is stopped, and the temperature of the bending jig 3 is allowed to lower quickly. Thereafter, the synthetic resin tube 1 is removed from the bending jig 3. |
