A drive control method of a hydraulic actuator of a construction machine includes: determining whether a rotation operation lever and a working device operation lever are operated; calculating the required pressure of a hydraulic cylinder fix a working device according to the operation amount of the rotation operation lever; calculating the required flow rates of a swing motor and the hydraulic cylinder for the working device, the required flow rates corresponding to the operation amounts of the working device operation lever and the rotation operation lever; calculating the opening areas of the first and second proportional solenoid valves of an inlet side and an outlet side by using the calculated required pressure and required flow rates of the hydraulic cylinder for the working device and the swing motor; and calculating current values to be inputted into the first and second proportional solenoid valves of the inlet side and the outlet side according to preset data values or a table in comparison with the calculated opening areas of the first and second proportional solenoid valves of the inlet side and the outlet side.

Agricultural implements and hydraulic circuits for agricultural implements are disclosed herein. An agricultural implement includes a fluid source, a plurality of fluid demand devices, a delivery control valve, and a priority valve. The fluid source is configured to supply hydraulic fluid. The plurality of fluid demand devices are each configured to receive hydraulic fluid supplied by the fluid source during operation of the agricultural implement. The delivery control valve is fluidly coupled between the fluid source and a first fluid demand device. The delivery control valve is configured to selectively deliver hydraulic fluid supplied by the fluid source to the first fluid demand device during operation of the agricultural implement. The priority valve is fluidly coupled between the delivery control valve and the first fluid demand device.

The present invention is related to a construction machine, the construction machine including: a main pump; a swing motor operated by receiving a hydraulic oil from the main pump; a swing valve configured to control flow of the hydraulic oil by the main pump to supply the hydraulic oil to the swing motor and to control the flow of the hydraulic oil having been discharged from the swing motor; a hydraulic oil control valve unit provided between the swing motor and the swing valve and configured to control the flow of the hydraulic oil according to a pressure of the hydraulic oil at opposite ends; a first accumulator configured to store the hydraulic oil having passed through the hydraulic oil control valve unit when the swing motor is decelerated; a regeneration control valve provided between the hydraulic oil control valve unit and the first accumulator; and a controller configured to control the hydraulic oil control valve unit and the regeneration control valve by determining acceleration or deceleration of the swing motor.

Multi-rotor hydraulic drone (1) comprising: —a plurality of hydraulic motors (6) each receiving a pressurised fluid, —propellers (5) driven by the hydraulic motors (6), —at least one hydraulic pump (10) driven by at least one motor (11) for pressurising the fluid, —a system for supplying the hydraulic motors (6) with pressurised fluid, —a flight controller (14) for controlling the supply system according to the desired rotation speed for the hydraulic motors (6), the supply system comprising several channels (35; 36; 37; 38) for adjusting the power of at least one portion of the hydraulic motors (6).

A working machine includes: a plurality of hydraulic actuators including a high-load hydraulic actuator and a low-load hydraulic actuator whose hydraulic pressure for actuation thereof is lower than that of the high-load hydraulic actuator; a plurality of direction switching valves each of which switches a direction of a hydraulic fluid for a corresponding one of the hydraulic actuators, the plurality of direction switching valves including a low-load direction switching valve that switches a direction of hydraulic fluid for the low-load hydraulic actuator; and a dummy-load forming unit that forms a dummy load in the low-load direction switching valve to suppress a variation in an actuation speed of the low-load hydraulic actuator between a time when the high-load hydraulic actuator and the low-load hydraulic actuator are operated in combination and a time when the low-load hydraulic actuator is operated singly.

A confluence control part of a slewing-type construction machine controls a confluence switch valve such that the confluence switch valve is switched to a suspension state when a slewing and boom raising manipulation action is performed. A pump capacity control part of the slewing-type construction machine executes a capacity control when the slewing and boom raising manipulation action is performed, the capacity control including regulating a first pump capacity and a second pump capacity respectively in such a manner that the first pump capacity increases and the second pump capacity decreases as an operating pressure difference resulting from the subtraction of a slewing operating pressure from a boom operating pressure increases, and the first pump capacity decreases and the second pump capacity increases as the operating pressure difference decreases.

This disclosure relates to a hydraulic system for a hydro-mechanical machine comprising a rotary mechanism and a boom cylinder The hydraulic system includes a primary accumulator configured to receive and store high-pressure fluid in response to starting and stopping of the rotary mechanism. A control system configured to enable passage of the high-pressure fluid stored in the primary accumulator to a rotary control valve configured to control the rotary mechanism, and a boom control valve configured to control the boom cylinder through the hydraulic supply circuit, based on a predefined pressure threshold associated with the primary accumulator. A secondary accumulator coupled to the primary accumulator and the control system via the hydraulic supply circuit is configured to store surplus high-pressure fluid provided by the primary accumulator through the hydraulic supply circuit.

A system for controlling a hydraulic component. The system includes a control system configured to carry out a health check routine having steps of (A) fluidly connecting one of the hydraulic supply systems with the component until (i) a predetermined pressure is reached on the hydraulic supply side and/or the hydraulic return side, and/or (ii) a predetermined amount of time has passed; then (B) isolating the pressurised hydraulic fluid within the hydraulic supply side and the hydraulic return side so that hydraulic fluid leaks from the hydraulic supply side to the hydraulic return side via the controlled leakage; (C) monitoring the pressure of hydraulic fluid within the hydraulic supply side (50S) and/or the hydraulic return side over time; and then (D) determining if the pressure of hydraulic fluid within the hydraulic supply side and/or the hydraulic return side follows a predetermined or expected pattern.

A closed-loop hydraulic circuit associated with a swing mechanism of a machine is controlled to obtain both a pressure control during acceleration and deceleration of the swing mechanism and a velocity control during coasting. In this manner, a system pressure in closed-loop hydraulic circuit is maintained below a maximum allowable pressure during acceleration and deceleration, and the swing mechanism can be rotated at a desired constant speed during coasting. This is achieved by controlling a hydraulic actuator adjusting the displacement of a variable displacement pump in different control modes, depending on a comparison between a desired displacement of the pump and an actual displacement of the same.

A hydraulic system includes: a slewing motor; a mechanical brake; and a slewing control valve interposed between a main pump and the slewing motor. A first pilot port of the slewing control valve is connected to a first solenoid proportional valve by a pilot line. A second pilot port of the slewing control valve is connected to a second solenoid proportional valve by a second pilot line. The first solenoid proportional valve and the second solenoid proportional valve are connected to an auxiliary pump by a primary pressure line. A switching valve is interposed between the auxiliary pump and the mechanical brake. The switching valve includes a pilot port that is connected to the first pilot line by a switching pilot line. The valve switches from a closed to an open position when a pilot pressure led to the pilot port becomes higher than or equal to a setting value.