| 摘要 |
PROBLEM TO BE SOLVED: To provide a plunger pump capable of suppressing occurrence of failure with a simple configuration.SOLUTION: A plunger pump 1 includes a cylinder 2 having a cylinder chamber 2a, and a plunger 3 having a body part 31 moved with respect to the cylinder 2 by driving force transmitted from a stepping motor. A cutout 32 is formed on the body part 31, and liquid flows from an intake part 4 when the cutout 32 is positioned in the intake part 4, and the liquid flows out of a discharge part 5 when the cutout 32 is positioned in the discharge part 5. Four circular movable pieces 6 are formed in the body part 31. The plunger 3 is inserted into the cylinder 2 in a state that the movable pieces 6 of the body part 31 are diametrically reduced, and thereby, the movable pieces 6 press an inner peripheral surface of the cylinder 2 by elastic force. The movable pieces 6 are bent and displaced when a crystal of the liquid exists between the cylinder 2 and the movable pieces 6, and thus, locking can be prevented, and an operation state can be maintained. |
