| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily remove air bubbles in hydraulic oil which may reduce the performance of a hydraulic pump by providing a branch pipe forcedly opening means which opens a branch pipe which is closed by an open and close means forcedly. SOLUTION: First, when a nut 33 which is screw-fitted in a male screw 31 provided on an outer peripheral face of a rear end part in a shaft 32 is screwed in, the nut 33 comes into contact with a top face 38 of a setting bolt 28. Furthermore, when the nut 33 is screwed in, a position of the nut 33 does not move in the downward direction on the top face 38 of the setting bolt 28 so that the shaft 32 moves in the upward direction against energizing force of a spring 25 to pull up a disc 24 connected with a tip part 30 thereof. Since the disc 24 is formed in such a manner that a ball valve 18 can be lifted up while it faces down in a recessed part 21, the ball valve 18 leaves a valve seat part 19 in accordance with a rise of the disc 24, and air bubbles which reach a communicating hole 17 rise into an inner space 34.</p> |
