发明名称 |
HYDRAULIC CONTROL CIRCUIT FOR A HYDRAULIC LIFTING CYLINDER |
摘要 |
A hydraulic control circuit for a hydraulic cylinder is described for the raising and lowering of a boom on a telescopic loader. First and second chambers of the hydraulic cylinder are connected to a control valve over first and second supply lines and are selectively connected to either a hydraulic pressure source or to a hydraulic reservoir. The circuit includes on-off valves for controlling the flow throu gh a first hydraulic line extending between the first chamber of the cylinder and the hydraulic reservoir, and through a second hydraulic line extending between the second chamber and the hydraulic reservoir in such a way that a floating position can be provided. Furthermore, a load-holding valve arrangement is provided in the first suppl y line at a location between the control valve and the first chamber of the cylinder. To provide assurance against uncontrolled lowering of the boom during switching to the floating position under load, a valve arrangement is provided that controls the flow rate as a function of the flow rate.
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申请公布号 |
CA2457980(A1) |
申请公布日期 |
2004.08.21 |
申请号 |
CA20042457980 |
申请日期 |
2004.02.19 |
申请人 |
DEERE & COMPANY |
发明人 |
SCHLEMMER, STEFFEN;PRICE, DAVID;BITTER, MARCUS;ONNEN, MARLIN |
分类号 |
B66F9/065;B66F9/22;F15B11/00;F15B11/024;(IPC1-7):F15B11/024;F15B11/12 |
主分类号 |
B66F9/065 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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