| 摘要 |
PURPOSE:To contrive unification of a mold product by detecting the wear of a plunger or a pot in an early stage, by providing a detecting device of a sliding action of a plunger on each of the plungers. CONSTITUTION:A seat 12 and detecting pin 13 moving unitarily with a plunger 6 through an action of a spring 11 are held into a hole 14 in the lower part of plungers 6 and a light emitting appliance 16 and light receiving appliance 17 are arranged in the direction crossing at right angles with a sliding direction of the detecting pin 13. In the case where sleeve resistance between a pot 4a and plunger 6a is great, the plunger 6a is hard to ascend inspite of an ascent of a transfer cylinder 9. Therefore, a spring 11a starts to contract earlier as compared with the spring 11 in the lower part of the plunger 6 operating normally and light through a light emitting appliance 16a is interrupted by a detecting pin 13a before the lapse of (t) hours after starting of the transfer cylinder 9. Therefore, whether resin is cast into a cavity 7 normally can be judged by only detecting timing where light through the light emitting appliance 16 is shaded by a detecting pin 17. |
