| 摘要 |
<p>PURPOSE:To reduce elastic force of a reset spring for energizing a swash plate to a minimum displacement position by starting a pump always from minimum displacement equal to zero, suppressing riseup torque, attaining power saving, omitting an input cutoff mechanism of clutch or the like and also decreasing a pressure of a control chamber of a control cylinder, for increasing displacement at the time of stopping cargo handling action, to almost the atmospheric pressure. CONSTITUTION:A cargo handling switching valve 23 and a cargo handling actuator 24 are connected to a delivery port 17 of a variable displacement swash plate type piston pump 21 through a delivery pipe line 22. A control cylinder 19 is actuated by pressure oil supplied from the before-mentioned delivery pipe line 22 through a control pipe line 25, and a swash plate 11 energized to a minimum displacement position by a reset spring 18 can be press moved to a maximum displacement position. On the halfway of the above-mentioned control pipe line 25, a drain passage 35 for connecting a control chamber 19a of the control cylinder 19 to an oil tank T at the time of stopping cargo handling work is opened, to hold a pressure of this control chamber 19a to the atmospheric pressure.</p> |
