| 摘要 |
PROBLEM TO BE SOLVED: To make a plunger move easily even after repeated molding by forming a ring-shaped groove on the surface of the plunger contacting the inner wall surface of a pot and a groove in the shaft direction ranging from a part in which the ring-shaped groove was formed to a part of an end surface opposite to an end surface on the side contacting a resin for molding. SOLUTION: A resin A for molding is extruded by a plunger 17 and supplied into a cavity 13 through a passage 14 for transport. A groove 174 in the axial direction is formed on the surface of the plunger 17 contacting the inner wall surface of a pot 16. Air contained in the resin A generated by the pressurization by the plunger 17 is made to be removed easily from the part of the groove 174, the contact area between the plunger 17 and the pot 16 is reduced to decrease sliding resistance. Therefore the clearance between a part in which a part in which the groove 174 was formed is excluded from a part in which the groove 174 was formed and the pot can be reduced. |
