| 摘要 |
PROBLEM TO BE SOLVED: To successfully prevent the streaks of a parison consisting of a weldline, which streaks are easily generated at a confluence part of a crosshead of a hollow molding machine from occurring by virtue of the function of an overflow ring having a bypass groove and a pressure relief groove arranged adjacently in the downstream part of a manifold groove. SOLUTION: This crosshead of the hollow molding machine has the manifold groove (30) communicating with the inflow part 3 of a housing 4 and at least one set of the overflow ring 31 and the pressure relief groove 32 arranged in the downstream part of the manifold groove (30), formed in the outer peripheral wall of a core 5. In addition, the overflow ring 31 adjacent to the manifold groove (30) has a bypass groove 33 which transverses across a center axis 0-0 including positions for the inflow part 3 and the confluence part 30a on the opposite side, with the upper end of the bypass groove 33 communicating with the manifold groove (30) and the lower end communicating with the pressure relief groove 32 when viewed from a side face. A molten resin flowing into the manifold groove (30) from the inflow part 3 gets over the overflow ring 31 and flows into the pressure relief groove 32 by passing through the bypass groove 33. COPYRIGHT: (C)2004,JPO&NCIPI
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