| 摘要 |
<p>PURPOSE:To realize a structure of a port block on which divided openings are formed for branching discharge fluid by preventing deterioration of strength of a partition wall between the divided openings and discharge passages, and enabling watching of residual molding sand in the discharge passages from outside. CONSTITUTION:Divided openings 22, 22 are long in a direction of traversing a diameter direction of a piston driving shaft 18. The divide openings 22, 22 are moved in such a direction that they become more distant from each other along a longitudinal direction of the openings 22, 22. Discharge pressure introduction passages 23, 23 to a discharge pressure controlling piston communicated with the openings 22, 22 are opened to the outer side surface of a port block so as to sight deep portions 22a, 22a of the discharge passages.</p> |
