A construction machine is provided that can cause each hydraulic actuator to accurately operate according to operation by an operator in combined operation in which a hydraulic fluid of a hydraulic pump is subjected to flow dividing and is supplied to plural hydraulic actuators. A controller 10, in a case of determining that combined operation is being carried out, controls a regulator 7a in such a manner that the delivery flow rate of a hydraulic pump 7 becomes larger than the total target flow rate of plural hydraulic actuators 4a, 5a, and 6a, and controls the respective opening amounts of plural directional control valves 8a1, 8a3, and 8a5 in such a manner that the difference between the respective target flow rates of the plural hydraulic actuators and the respective inflow flow rates of the plural hydraulic actuators sensed by velocity sensors 12 to 14 becomes small.

A hydraulic system for a rear gate of a baler implement includes a fluid circuit having a first portion connected to and disposed in fluid communication with a first fluid port of a hydraulic cylinder. A flow bypass assembly is disposed in the first portion of the fluid circuit. The flow bypass assembly includes a flow rate control valve selectively moveable between a first position allowing fluid communication therethrough at a first flow rate, and a second position blocking fluid communication therethrough. The flow bypass assembly further includes a bypass passageway for circulating the fluid when the flow rate control valve is closed. A flow restriction is disposed within the bypass passageway to provide a second flow rate that is less than the first flow rate.

A control device for a hydraulic machine such as a revolving excavator work machine in which a load-sensing pump control system is adopted The control device prevents variation in pump control characteristics among a plurality of hydraulic machines and also prevents variation in the operating speed of individual drive units in the hydraulic machines The control device; and it is configured to perform, by using a storage unit and a calculation unit outside the hydraulic machine, a process of causing an engine rotation state and a hydraulic actuator operation state to be specific states and calculating a correction rate for a control output value of an electromagnetic proportional valve for generating a control pressure, based on detection of an error in the flow rate of a hydraulic pump or its substitute numerical value such as the rotational speed and the like of a traveling motor which is easily detectable from outside.

A system for controlling hydraulic fluid flow within a work vehicle includes a pilot conduit configured to receive a pilot flow of hydraulic fluid from a fluid supply conduit such that the operation of a compensator valve is controlled based on a pressure of the pilot flow within the pilot conduit. Furthermore, a pilot conduit valve is configured to adjust the pressure of the pilot flow within the pilot conduit. In addition, the system includes a load sense conduit configured to receive a bleed flow of the hydraulic from the fluid supply conduit such that the operation of the pump is controlled based on a pressure of the bleed flow within the load sense conduit. Moreover, a load sense valve is configured to adjust the pressure of the bleed flow within the load sense conduit.

The present disclosure relates to a hydraulic circuit comprising: a hydraulic displacement unit for driving an implement; a hydraulic machine fluidly connected or selectively fluidly connected with the hydraulic displacement unit the hydraulic machine having a fixed hydraulic displacement; an electric machine drivingly engaged or selectively drivingly engaged with the hydraulic machine; a hydraulic pump fluidly connected or selectively fluidly connected with the hydraulic displacement unit, the hydraulic pump having a variable hydraulic displacement; and an electric motor drivingly engaged or selectively drivingly engaged with the hydraulic pump.

A flow control circuit for an actuator is provided. The actuator includes a first chamber and a second chamber, wherein the first chamber experiences a volume change that is larger than a volume change experienced by the second chamber upon actuation of the actuator. The flow control circuit includes a first port configured to be connected to the first chamber, a second port configured to be connected to the second chamber, and a flow control valve assembly including one or more valves configured to provide a flow of pressurized fluid from a pressurized fluid source to one of the first and second ports along a fluid supply path and further configured to provide a flow of fluid from the other of the first and second ports to a fluid sink along a fluid return path. The flow control circuit further includes a fluid bypass path comprising a bypass valve.

Disclosed are a slit valve apparatus and a method for controlling a slit valve. The slit valve apparatus includes a slit valve assembly and a servo-control system in communication with the slit valve assembly. The slit valve assembly includes at least one gate able to transition between an open position and a closed position, at least one pneumatic actuator, at least one proportional pneumatic valve including a plurality of controllers, and a continuous position sensor. The servo-control system includes a centralized controller that generates a control signal and adjusts the movement of the at least one gate based on the position trajectory for the gate, a linear position measurement of the gate from the continuous position sensor, and fluid pressure/flow measurements from the plurality of controllers.

A control device for a hydraulic machine such as a revolving excavator work machine in which a load-sensing pump control system is adopted. The control device prevents variation in pump control characteristics among a plurality of hydraulic machines and also prevents variation in the operating speed of individual drive units in the hydraulic machines. The control device; and it is configured to perform, by using a storage unit and a calculation unit outside the hydraulic machine, a process of causing an engine rotation state and a hydraulic actuator operation state to be specific states and calculating a correction rate for a control output value of an electromagnetic proportional valve for generating a control pressure, based on detection of an error in the flow rate of a hydraulic pump or its substitute numerical value such as the rotational speed and the like of a traveling motor which is easily detectable from outside.

A hydraulic system for an agricultural baler includes: a hydraulic motor; a hydraulically driven component fluidly coupled to the hydraulic motor such that fluid flow between the hydraulic motor and the hydraulically driven component causes the hydraulically driven component to move between a first position and a second position; a flow sensor associated with the hydraulically driven component; and a controller operatively coupled to the flow sensor and the hydraulic motor. The controller is configured to: enter a learning mode to learn a driven movement of the hydraulically driven component from the first position to the second position; determine fluid flow between the hydraulic motor and the hydraulically driven component during the driven movement while in the learning mode; associate the determined fluid flow with the driven movement; and output control signals to the hydraulic motor to reproduce the associated fluid flow and reproduce the driven movement.

Provided is a construction machine including a hydraulic system having a hydraulic pump, and a first hydraulic actuator and a second hydraulic actuator which are driven by hydraulic oil supplied from the hydraulic pump. The construction machine includes a first flow rate detector that detects a flow rate of drain hydraulic oil discharged from the first hydraulic actuator, a second flow rate detector that detects a flow rate of drain hydraulic oil discharged from the second hydraulic actuator, and an abnormality determination unit that determines abnormality of the first hydraulic actuator, based on a detection signal from the first flow rate detector, and determines abnormality of the second hydraulic actuator, based on a detection signal from the second flow rate detector. The first flow rate detector and the second flow rate detector each have a moving body.