A load sense pressure regulating system is provided. The load sense pressure regulating system can be operable between a flow regulation mode and a pressure limiting mode. When the load sense pressure control system is in the flow regulation mode, flow between a load sense inlet and a pilot vent are metered by a main poppet. The load sense pressure regulating system can also include a control valve downstream from the pilot vent that is configured to control a relief setting of a relief valve to regulate the load sense pressure within a desired operating range.

A working machine includes a machine body, a first hydraulic actuator mounted on the machine body, a first control valve that controls the first hydraulic actuator, a controller that controls the first control valve, and a second hydraulic actuator that is different from the first hydraulic actuator. When the second hydraulic actuator and the first hydraulic actuator are operated in combination, the controller reduces the amount of change in the flow rate of a hydraulic fluid supplied from the first control valve to the first hydraulic actuator with respect to changes in a manipulation amount to operate the first hydraulic actuator to a value smaller than that when the first hydraulic actuator is solely operated.

A hydraulic system for controlling an implement on a work machine may include a hydraulic reservoir, a hydraulic pump in fluid communication with the reservoir, a central valve in fluid communication with the pump and configured for controlling the implement, a load sense pressure relief system, and a controller. The controller may be configured for controlling the central valve and the load sense pressure relief system and selecting between operating the hydraulic system at a first pressure and a second pressure based on a factor relating to implement position.

A system for controlling hydraulic fluid flow within a work vehicle includes a flow control valve fluidly coupled to a fluid supply conduit upstream of a hydraulic actuator such that the flow control valve is configured to control the flow rate of hydraulic fluid to the hydraulic actuator. Furthermore, the system includes a computing system configured to receive an input associated with a selected flow rate of the hydraulic fluid being supplied to the hydraulic actuator. Moreover, the computing system is configured to control an operation of the flow control valve such that flow control valve is at a maximum flow position at which an adjustable orifice defined by the valve has a maximum cross-sectional area. Additionally, the computing system is configured to control an operation of a pump such that the pump supplies the hydraulic fluid to the hydraulic actuator through the adjustable orifice at the selected flow rate.

A hydraulic system is provided, the hydraulic system including a hydraulic load defining a first chamber and a second chamber. Additionally, the hydraulic system includes a pressure source, a fluid storage vessel, a load sense line, and a spool valve. The spool valve fluidly connects the fluid storage vessel to one of the first or second chambers and fluidly connects the pressure source to the other of the first or second chambers. A bypass line is also provided defining a flow path between the hydraulic load and the fluid storage vessel that bypasses the spool valve. Fluid flow may encounter less resistance through the bypass line, such that the hydraulic system may run more efficiently and with a reduced risk for cavitation in the hydraulic load.

A compensator spool of a load sensing valve device includes a pressure chamber, a compensator throttle portion, a pressure introduction chamber, a pressure introduction port, a maximum load pressure introduction chamber, and a selector valve. A groove is formed around the pressure introduction port, and a groove moves relatively between a passage communicating with an actuator to reduce an opening area of the pressure introduction port when the compensator spool moves.

A hydrostatic drive includes a diesel engine and a hydrostatic adjustable machine which supplies multiple consumers in normal operation as a pump. The machine has a pressure/flow regulator to which is communicated, according to the load-sensing principle, the highest load pressure of the consumers, in particular when the machine is operated as a pump. In order to realize a start/stop function of the diesel engine, a previously charged high-pressure reservoir supplies the hydrostatic machine, which then acts as a starter motor for the diesel engine. In order to switch from pump to starter motor, the hydro-machine is adjusted over zero. In order for this switch to take place quickly and reliably, the pressure/flow regulator is deactivated by means of a switching valve and the adjustment device is supplied with an adjustment pressure medium via the switching valve, which medium is taken from the high-pressure reservoir or from an auxiliary reservoir.

A hydraulic control assembly for a plurality of consumers includes, for each consumer, a supply metering orifice configured to control fluid flow. A flow-sensing fluid-flow-path extends over detection orifices positioned hydraulically in series, whereby a detection orifice is assigned to each supply metering orifice. The fluid-flow-path is connected to a hydraulic pump upstream of the detection orifices, and a control device of the hydraulic pump downstream of the detection orifices. Each detection orifice is configured to close the fluid-flow-path upon detecting a fluid supply deficiency for a corresponding consumer, whereby the control device is configured to interact with the fluid-flow-path such that fluid flow from the hydraulic pump is increased. When no customers have a supply deficiency, the fluid-flow-path over the detection orifices is fully opened, and the control device is configured to reduce fluid flow from the hydraulic pump.

To provide a work machine that makes it possible to drive actuators faster and more accurately by supplying flows to the actuators accurately at target rates without depending on load variations in a case where the machine body is controlled automatically by command inputs of a controller, while high operability is ensured for manual operation by an operator. In a case where a machine control function is cancelled via a machine control switch, a controller cancels limitation of the flow rate of a hydraulic fluid supplied to a plurality of directional control valves, the limitation being performed by the auxiliary flow rate control devices, and in a case where the machine control function is selected via the machine control switch, the controller causes the auxiliary flow rate control devices to limit the flow rate of the hydraulic fluid supplied to the plurality of directional control valves.

A hydrostatic drive includes a hydraulic machine, a hydraulic adjusting device, a high-pressure accumulator, an accumulator-closing valve, and an electronic control unit. The hydraulic machine has a swept volume that is adjustable via the hydraulic adjusting device from a maximum positive swept volume to a maximum negative swept volume via a zero swept volume. The hydraulic machine is operated as a pump with positive swept volume and as a motor with negative swept volume. The high-pressure accumulator supplies the hydraulic machine with pressure medium for operation as a motor via a pressure line. The accumulator-closing valve has a first position and a second position and is arranged in the pressure line. A fluidic connection from the high-pressure accumulator to the hydraulic machine is open in the first position and closed in the second position. The accumulator-closing valve is actuated in accordance with signals from the electronic control unit.