4.
    发明专利
    未知

    公开(公告)号:DE2232857A1

    公开(公告)日:1974-01-17

    申请号:DE2232857

    申请日:1972-07-05

    Abstract: Apparatus which controls the flow of pressurized hydraulic fluid from a pump to a primary consumer or to a secondary consumer and from the primary consumer to the tank has a distributor valve whose spool changes its position in response to changes of fluid pressure in a control chamber wherein the fluid pressure is controlled by a pilot valve which can be actuated manually, electrically or by means of a fluid. A check valve which is interposed between the distributor valve and the primary consumer controls the speed of movement of the spool of the distributor valve to that position in which the primary consumer receives fluid. The secondary consumer receives fluid whenever the primary consumer is sealed from the pump. A further pilot-controlled valve is provided to control the flow of fluid from the primary consumer to the tank.

    Operating part for an electrohydraulic lifting-unit regulating device of tractors

    公开(公告)号:DE3522823A1

    公开(公告)日:1987-01-02

    申请号:DE3522823

    申请日:1985-06-26

    Abstract: What is proposed is an operating part (22) for the input of regulating quantities in an electrohydraulic lifting-unit regulating device (11) of a tractor (10), in which not only the basic settings for lift-out, desired value and mode of regulation, but additional settings are possible in three operating axes (34, 35, 36) by means of appropriately arranged adjusting elements (41 to 46). The second adjusting element (42) is arranged on a second, middle operating axis (35) as a handy operating knob for desired-value input which uses the same scale (51) together with the coaxial fourth adjusting element (44) for limiting the end position of the lifting unit (19) in the upward direction and clearly indicates the range between desired value and limitation. The order of priority of the end-position limitation on the fourth adjusting element (44) before a lower end-position limitation by the first adjusting element (41) working proportionally and of the latter before the desired value of the second adjusting element (42) allows an appropriate functional setting of the working range for the regulating device (11).

    Control valve arrangement with at least two directional control valves in double-flow construction

    公开(公告)号:DE3131116A1

    公开(公告)日:1983-02-24

    申请号:DE3131116

    申请日:1981-08-06

    Abstract: A control valve arrangement (10) for stacker trucks is proposed which serves to control two consumers in parallel at different pressure levels. It comprises at least two directional control valves (14, 15) in double-flow construction, from which, downstream of the latter valve, a circulation passage (26) allocated to the first flow and a distribution passage (25) allocated to the second flow are brought together via a first transverse connection (51). From there (51), a second transverse connection (56) leads via an additional directional control valve (12) in single-flow construction to the second circulation passage (27) upstream of the directional control valves in double-flow construction and further via these directional control valves to the tank (34). In this way, simple, standard directional control valves (12) in single-flow construction can be combined with directional control valves (14, 15) in double-flow construction and can control flows of different magnitude. In addition, different pressure protection measures can be carried out for both flows.

    10.
    发明专利
    未知

    公开(公告)号:DE2244445A1

    公开(公告)日:1974-03-21

    申请号:DE2244445

    申请日:1972-09-11

    Abstract: A control system for first and second double-acting hydraulic cylinders which respectively cause the endgate of a truck to pivot between open and closed positions and to move up or down. The flow of fluid into and from the lower chambers of the cylinders is controlled by discrete three-position twoway control valves, and the flow of fluid from the upper chamber of the first cylinder to a tank is controlled by an auxiliary valve assembly which acts as a pressure relief valve. If the endgate cannot displace the piston of the first cylinder due to its own weight, the auxiliary valve assembly is actuated to start a pump which delivers pressurized fluid to the upper chamber of the first cylinder. The upper chamber of the second cylinder can be connected directly to the tank or is connected with a line which conveys fluid from the upper chamber of the first cylinder to the auxiliary valve assembly.

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