PURPOSE: To perform a volume control of a high responsiveness and improve the reliability by forming a guide groove in a such a shape as to move an inclined plate to finely increase a clearance volume at an upper dead center as a piston stroke decreases at the time of volume control and to make an inclination angle small.
CONSTITUTION: For a guide groove 122, a normal line constantly passes a close position to a drive shaft 13 than an instantaneous rotation center OC of an inclined plate 12. This means that it is formed to make an angle formed by the normal line and a parallel line to the drive shaft 13 smaller than conventional. When the position of the guide groove for the maximum volume is set at the same position as conventional, the position of the guide groove corresponding to volume control is formed to be positioned on the opposite side of the piston as compared with conventional. In this constitution, the inclination angle of the inclined plate 12 can be changed with a smaller force than conventional to achieve volume control. For volume control, the piston stroke is decreased, and the position of a piston 31 at an upper dead center is changed, so the clearance volume is increased finely.
TAKAO KUNIHIKO
SATO EIJI
