| 摘要 |
<p>A hydraulic circuit for construction equipment is disclosed, which can prevent an abrupt rotation of a swing device when a switching valve (7,8) for the swing device is shifted in a state that switching valves (3,4,1,2,5,6) for a traveling device and a working device have been shifted. The hydraulic circuit includes first to fourth hydraulic pumps (P 1 ,P 2 ,P 3 ,P 4 ); first to six (1-6) switching valves installed in the first to second hydraulic pumps, respectively, and shifted to control hydraulic fluid fed to working devices or traveling devices; a confluence switching valve (9) installed in the third hydraulic pump (P 3 ) and shifted to supply the hydraulic fluid to the working devices (1,2,5,6) on the first (P 1 ) and second (P 2 ) hydraulic pump sides; signal lines (15,16) for the traveling devices and the working devices; a first valve (21) connected between the signal line (15) for the traveling device and an intersection between the signal line (17) for the confluence switching valve (9) and a tank line (18); and a second valve (22) installed in a flow path (17a) between the first valve (21) and the tank line (18), shifted to discharge pressure in the signal line (17) for the confluence switching valve (9) to the tank line (18) or to block the flow path (17a) to form the signal pressure in the signal line (17) for the confluence (9).</p> |
