A fluid control system for supplying fluid to a fluid consumer, having a valve module including a channel body to which a fluid switching valve, a fluid pressure regulator and a vacuum switching valve are attached, the channel body having a first fluid channel extending from a fluid input port to an input port of the fluid pressure regulator and having a second fluid channel extending from an output port of the fluid pressure regulator to an input port of the fluid switching valve, and having a third fluid channel extending from an output port of the fluid switching valve to a fluid consumer port, and having a first vacuum channel extending from a vacuum input port to an input port of the vacuum switching valve, and having a second vacuum channel extending from an output port of the vacuum switching valve to the fluid consumer port.

A system for adjusting actuator pressure on an agricultural implement includes a fluid-driven actuator configured to adjust a position of a tool of the implement relative to the implement frame, with the fluid-driven actuator defining a fluid chamber. Furthermore, the system includes a valve configured to control a flow of a fluid to the fluid-driven actuator. In addition, the system includes a fluid conduit fluidly coupled between the valve and the fluid chamber. Moreover, the system includes a computing system is configured to determine the current position of the tool relative to the implement frame based on the data captured by a position sensor. Additionally, the computing system is configured to determine a current volume of the fluid chamber and the fluid conduit based on the determined current position. Furthermore, the computing system is configured to control the operation of the valve based on the determined current volume.

Provided is a work vehicle which can prevent an engine from stalling regardless of type of a system mounted on a vehicle body. In a wheel loader 1 equipped with a loading work device 11 operated by an electric operation lever 19, first and second directional control valves 5, 6 include neutral positions 5N, 6N for causing hydraulic oil discharged from a hydraulic pump 12 to return to a hydraulic oil tank 10, respectively, and in the case where a discharge pressure P of the hydraulic pump 12 is a main relief pressure Pr or more and an engine rotational speed N is less than a low idle rotational speed NL, a controller 2, 2A restricts the output of control signals to first and second solenoid control valves 3, 4 so as to cause the first and second directional control valves 5, 6 to be switched to the neutral positions 5N, 6N, respectively.

A system for controlling hydraulic fluid flow within a work vehicle includes a load sense valve configured to adjust the pressure of a bleed flow within a load sense conduit. Moreover, the system includes a computing system configured to determine the pressure of the hydraulic fluid within the fluid supply conduit downstream of the flow control valve based on the data captured by a pressure sensor. Furthermore, the computing device is configured to control an operation of the load sense valve to selectively adjust the pressure of the bleed flow within the load sense conduit based on the determined pressure.

This control device controls movement of a valve body of a valve device included in a hydraulic system and includes: a stroke command calculator that calculates a stroke command for the valve body on the basis of an opening command that is input to the stroke command calculator; an observer that estimates, on the basis of the stroke command, a dynamic deviation of a stroke of the valve body that corresponds to the stroke command; and a flow force estimator that estimates, on the basis of the stroke command and the dynamic deviation, a flow force acting on the valve body. The stroke command calculator calculates the stroke command on the basis of the flow force in addition to the opening command.

The present invention provides a construction machine equipped with a pressure accumulation device that accumulates return oil from an actuator, and that can implement both improvement in fuel efficiency with enhancement in workability. To achieve the foregoing, a controller sets an actuator upper limit output power that is an upper limit for an output power of the actuator according to a work mode selected by a work mode selection device, and controls a first control valve and a second control valve such that a sum of an output power of a hydraulic pump and an output power of the pressure accumulation device does not exceed the actuator upper limit output power.

A control system is provided for a diesel particulate filter (DPF) system of a diesel engine configured for operation in an off-highway vehicle. The control system includes a controller configured to receive a signal corresponding to a fill state of the DPF being at or above a first threshold. The controller is configured to selectively induce a parasitic load on the diesel engine to increase an operating temperature of the engine in response to receiving the signal.

A hydraulic system may include a first actuator to control a first linkage member, a second actuator to control a second linkage member, a first primary hydraulic circuit and a first secondary hydraulic circuit that include the first actuator, a second primary hydraulic circuit and a second secondary hydraulic circuit that include the second actuator, a first pump to cause fluid to flow through the first primary hydraulic circuit and the second secondary hydraulic circuit, a second pump to cause fluid to flow through the second primary hydraulic circuit and the first secondary hydraulic circuit, and a controller. The controller may be configured to determine that an operator assistance mode is enabled, and cause closing of a first valve that controls fluid flow through the first secondary hydraulic circuit and a second valve that controls fluid flow through the second secondary hydraulic circuit.

It is an object of the present invention to provide a construction machine capable of efficiently driving a hydraulic cylinder by an accumulator. Thus, the construction machine includes a first control valve disposed in a first hydraulic fluid line connecting a bottom-side fluid chamber of a hydraulic cylinder with an accumulator, and a second control valve disposed in a second hydraulic fluid line connecting a rod-side fluid chamber of the hydraulic cylinder with a tank. The construction machine further includes a third control valve disposed in a third hydraulic fluid line connecting the rod-side fluid chamber with the accumulator, and a fourth control valve disposed in a fourth hydraulic fluid line connecting a line part of the first hydraulic fluid line, which connects the bottom-side fluid chamber with the third control valve, and a line part of the third hydraulic fluid line, which connects the rod-side fluid chamber with the third control valve, with each other.

A hydraulic fluid pressure amplifier system includes a boost cylinder assembly, an energy storage device in fluid communication with the boost cylinder assembly, and a working cylinder assembly. The boost cylinder assembly is configured to selectively receive a plunger member into a boost cylinder, wherein movement of the plunger member received in the boost cylinder compresses a charge fluid within a blind side volume of the boost cylinder from a first fluid pressure to an amplified fluid pressure greater than the first pressure. The working cylinder assembly is selectively operable responsive to receiving a source hydraulic fluid having a nominal fluid pressure less than the amplified fluid pressure for effecting the movement of the plunger member into the boost cylinder. The energy storage device is operable to selectively receive and store a portion of the charge fluid compressed to the amplified fluid pressure.