| 摘要 |
PURPOSE:To permit a sufficient power to be developed by the operation of a control means by installing a cut-off valve for reducing the discharge amount when the discharge pressure exceeds a set pressure and installing a means for increasing the set pressure of the cut-off valve. CONSTITUTION:When a manual selector valve 11 is switched to right-side position, the bottom-side chamber 10b of a cylinder 10 communicates to a branched passage 4 through the second and the first ports 11b and 11a of the manual selector valve 11. A portion of the fluid discharge from a variable capacity pump is introduced into the bottom-side chamber 10b of the cylinder 10, passing through the manual selector valve 11, and the spring 9 of a cut-off valve 7 is compressed by the piston rod 10a. Therefore, the force of the spring 9 is strengthened by the above-described compression portion, and the set pressure of the cut-off valve 7 is increased. |
