The present utility model is formed by adding a set of devices to the head of an existing hollow blow molding machine. A motor drives a driving gear on a reducer and a cam on a driven gear to perform circular motion. A roller meshed with the cam and a core rod connected thereto are restricted by a guide key to move up and down relative to the die along the curved surface of the cam, so that the gap between the core rod and the die is reduced or increased. According to the wall thickness requirements of plastic products, the wall thickness of the hollow blow molding parison can be continuously controlled with the rotation of the cam, so that the wall thickness of plastic hollow products is uniform, the stress caused by uneven wall thickness of plastic hollow products is further eliminated, defects such as surface shrinkage marks are reduced, raw materials are saved, and a discontinuous control hydraulic servo control system with very high cost and maintenance requirements is avoided, reducing production cost and having great social benefits.
Country Code: CN
Application Number: CN03230125.1
