To provide a plunger pump and its discharge control method capable of obtaining a desired compressibility, easily changing the discharge quantity without changing the stroke of the plunger and the inside diameter of the plunger's sliding hole, and exactly discharging a certain quantity of fluid by preventing the fluid leakage.
The plunger pump 1 is provided with a cylinder 2 having a suction port 8 to suck fluid and a discharge port 10 to discharge the sucked fluid, a through-hole 6 formed in the cylinder 2 to communicate with the discharge port 10, a plunger 4 slidably fitted into the through-hole 6 to form a pumping chamber 20 to suck and discharge the fluid between the discharge port 10, and a fluid suction passage 12 formed in the cylinder 2 to connect the pumping chamber 20 and the suction port 8. An opening port 19 of the fluid suction passage 12 opening to the pumping chamber 20 is opened and closed by the plunger 4 itself sliding in the through-hole 6.
KUSANAGI HIDEAKI
Koji Mizuno
Toshiro Nakamura