| 摘要 |
PROBLEM TO BE SOLVED: To provide a forced valve type piston pump capable of suppressing a jet sound.SOLUTION: While a discharge process is switched to a water absorption process so that a portion 22a on the inner circumference side of a protrusion 22b protruding backward on the outer circumference side of a stopper 22 and a dummy support 21b leave each other, while the stopper 22 is moving together with a piston rod 7 backward of an axial line. Thus, the dummy support 21b is prevented from abutting against the inner circumference portion 22a and from clogging the outer circumference side of the communication part 22a. As a result, a communication part 22c is more enlarged in a flow passage area than that of the prior art, thereby to prevent an abrupt flow speed change. |
