| 摘要 |
PROBLEM TO BE SOLVED: To solve the defect that a push-down head for a vertical pump with a valve rod for automatically opening and closing a nozzle hole becomes heavy in its push-down operation. SOLUTION: In the push-down head 21 constituted so that the inside of the upper part of the push-down head 21 engaged with the upper end part of a stem 6 is formed as a small cylinder 22 horizontally provided in the front and back direction, a 2nd discharge valve 25 is formed from the front end of the valve rod 24 pressed forward into and engaged with the small cylinder and the nozzle hole 23 on the front wall of the small cylinder and is opened and closed when the push-down head 21 ascends and descends to move the valve rod forward and backward, the push-down head 21 is engaged with the stem 6 to be movable vertically to the stem 6 with a small stroke, the stem 6 upper part is inserted into an inserting through hole 29 of the small cylinder bottom wall 22a to surround the inserting through hole and a 2nd cylindrical piston 31 engaged with the stem upper part to enable to slide is engaged with the inside of a small auxiliary cylinder 30 communicating with the small cylinder 22 and hanging down and enables to descend by highly pressurizing the inside of the auxiliary cylinder with the descending of the push-down head. |
