APPARATUS FOR JUDGING QUALITY OF MOLDED PRODUCT IN INJECTION BLOW MOLDING MACHINE

摘要

PURPOSE:To judge the quality of a molded product by providing a small hole to the predetermined part of a blow mold so as to pierce the mold from the outer surface thereof to the inner surface thereof to inject a fluid in the small hole and judging the presence of the gap between the molded product and the inner surface of the mold of the basis of a change of the pressure in the small hole before and after injection. CONSTITUTION:A small hole 19 is provided to the predetermined part of a blow mold 16 and the judge part 20 connected to the small hole 19 is provided. This judge part 20 has a switch 22 containing a change-over valve and a pressure detector 23 and the switch 22 allows an air supply part 21 to communicate with the small hole 19 when the quantity of a molded product 17 after a blow process is judged and air is injected in the small hole 19 from an air supply part 21. At this time, a change of the pressure in the small hole 19 in a case having a gap 18 is larger than that in a case having no gap. The pressure in the small hole 19 after the injection of air can be known by the pressure detector 23. The pressure in the small hole 19 before the injection of air is atmospheric pressure. Therefore, the judge part 20 can know a change of the pressure in the small hole 19 before and after the injection of air.