Hydac Filtertechnik Gmbh

Bucher Hydraulics Gmbh

Hydac Fluidtechnik Gmbh

Winfried Rüb

A hydraulic valve device has a valve housing () in which an activating piston () is guided in a movable manner. The activating piston () is actuatable by an actuating device () and activates a pilot valve () to connect a fluid port (T) in the valve housing () to a fluid chamber () of a shut-off piston (). The shut-off piston () activates at least one fluid-conducting connecting line () of the valve device and has a fluid conducting control line () opening from the connecting line () into the fluid chamber () of the shut-off piston ().

Hydraulic valve device

A method for operating a hydraulic system has at least one supply device, in particular a hydraulic pump () supplying different hydraulic consumers. A synchronizing device () ensures that, if at least one hydraulic consumer is not supplied sufficiently, the deficit in volumetric flow for that consumer is compensated such that all the consumers compensate for the deficit equally.

Method for operating a hydraulic system, and hydraulic system

A hydraulic valve device has a fluid port arrangement () with various ports extending at least partially in the valve housing (), and has a movable control device () for at least partially activating the ports. The control device () can be acted on at two opposite control sides with a control pressure (X, X) of an activation unit (). A valve device of narrow construction and functionally reliable is created by a media-conducting duct () with a guide path extending at least partially as an open duct channel that can be closed off by a cover part or by other housing parts of the multi-part valve housing (), to conduct the control pressure (X) from the activation unit () to the assignable control side of the control device ().

A hydraulic valve device, especially an LS current regulating valve, includes a fluid connection arrangement (). As the respective control device () associated with a useful connection (A) comprises a control slide () upstream of which a pressure balance () is mounted in the fluid direction towards each useful connection (A, B), any system vibrations occurring in the load sensing regulating circuit can be better controlled and the respectively connected hydraulic consumer can be subjected to a constant current regulation.

A valve arrangement has an adjustable control valve () including a control slide () for actuating at least one consumer connection (A, B) and an LS control line. The differential pressure of two actuating pressures (x, x) serves for the actuation of the control slide (). Since the actuating pressures (x, x) also actuate a logic valve, which in turn influences an additional valve, and/or actuates a pressure compensator connected upstream to the control valve (), the difference of the two actuating pressures (x, x) initially displaces the control slide of the control valve. The higher or the lower of the two actuating pressures (x, x) either actuate the further valve in the form of the additional valve, and/or influences the pressure compensator.

Valve arrangement

A hydraulic valve device includes a fluid connection arrangement () having different connections and a mobile control () for at least partially controlling connections of the fluid connection arrangement (). The control () is provided with load reporting and load detecting connections (). According to the displacement position of the control (), at least one part of the connections of the fluid connection arrangement () are interconnected in a fluid-guiding manner. The control can then be brought with precision into the required functional positions, with a favorable dynamic driving behavior.

A hydraulic valve device, especially in the form of at least one load sensing valve, includes a valve housing (), a control slide () longitudinally movable in the housing and controlling a fluid connection arrangement (). The fluid connection arrangement includes at least one control pressure line (P) and at least one supply pressure line (Y). At least for a load sensing connection (LS), a pocket-type channel () is arranged between the valve housing () and the control slide (), as well as for a control pressure line (P) and a supply pressure line (Y). This arrangement enables the available ring channel of the load sensing message chain to be used on axial point of the control slide axle, reducing cost and space.

A controlling device for hydraulic consumers () has one controlling valve () for controlling a supply pipeline (T) for the hydraulic consumer () and a tank return pipeline (T). Because the control valve () is connected to an additional supply pipeline (T) and constructed as a priority valve, the supply pipeline (T) receives priority preference of a fluid supply system over the priority of the tank return pipeline (T). A sensor circuit is realized which checks whether, in accordance with the load situation at the hydraulic consumer (), there is any need at all for a supply flow.

Controlling device for hydraulic consumers

The invention relates to a control valve () for controlling the pressure and flow of hydraulic oil from or to the working connections (A, B) of a consumer. The pressure and the pressure flow are controlled by means of at least one sliding piston which can be actuated by at least one drive mechanism and which can be displaced in a slider hole and in co-operating annular channels. The invention is characterized in that the annular channels are symmetrically arranged, whereby a tank connection annular channel is arranged in the symmetrical centre point on a symmetrical axis. Annular channels associated with the working connections (A, B), pump-pressure annular channels, load-sensing annular channels and end-chamber annular channels are arranged behind each other on both sides. According to the invention, the latter can be connected to other channels. The aim of the invention is to create equivalent hydraulic ratios for both working connections A and B and to keep the number of control edges in the control valve to a minimum.

Control valve

A directional control valve includes a pressure regulator piston configured as a hollow slide with a radial passage positioned in such a way that a connection from the internal chamber of the pressure regulator piston to a pump pressure annular channel (P) can be regulated by the radial passage and a second radial passage of a directional control valve piston. The second radial passage constitutes a control edge, which is used to regulate the connection from the internal chamber to a load sensing annular channel (LS). An annular groove, which in the neutral position forms a connection from the internal chamber to the load sensing annular channel (LS), is joined to the second radial passage. The pressure regulator is impervious to different flow forces caused by different mass fluxes and ensures that the hydraulic consumer is prevented from moving in the neutral position.

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Waldshut-Tiengen, Germany

Winfried Rüb