VENT HOLE ON-OFF VALVE AND MOLD EQUIPPED THEREWITH

摘要

PROBLEM TO BE SOLVED: To effectively suppress the generation of biting of rubber into a gap between a valve seat and a valve plug and the generation of penetration of fine particles into a vent hole or the clogging of the vent hole with fine particles. SOLUTION: A vent hole on-off valve consists of a tubular vent substrate 6 having a guide hole 7 in which a rearwardly turned valve seat is provided, a spherical valve plug 9 capable of opening and closing the guide hole 7 and a spring 10 energizing the valve plug 9 toward the valve seat 12. The valve seat 12 has a valve seat surface 14 inclined rearwardly from a valve hole 13 and the guide hole 7 is equipped with a rubber sump part 15 for which the diameter is maximum at a part of the inner end surface 6S of the vent substrate 6 and reduced toward the valve hole 13.