摘要:
An actuator displacement measuring system in an electro-hydraulic system for a construction machine is disclosed, which can detect an actuator displacement using the characteristics of an electro-hydraulic system. The actuator displacement measuring system includes controlling driving of an electric motor, determining whether the electric motor is driven, determining whether a set pressure value of a relief valve is larger than or equal to a measured pressure value of the hydraulic system if a displacement value of an actuator that is always detected deviates from a zero value of a reference position, setting the actuator displacement value to a previous value if a pressure value of the hydraulic system is larger than or equal to a pressure value of a relief valve and calculating the actuator displacement value using a rotating speed of the electric motor.
摘要:
An apparatus for the electrohydraulic control of the parallelism of a roller in a bending machine for working metal pieces, has a first and second pumps for supplying with an operating fluid a first and second actuators, position transducers and a first and second proportional valves to adjust the flow of the operating fluid into the first and second actuators according to signals of the position transducers.
摘要:
A hydraulic excavator includes a base body portion, a movable portion, a hydraulic cylinder, a position sensor, a rotary encoder, and a control unit. The rotary encoder includes a light emitting unit, a light receiving unit, and a disk unit having a plurality of transmission portions. The control unit measures the stroke length of the hydraulic cylinder by correcting deviation of the stroke length, which is measured by the position sensor, based on the pulse signal output from the rotary encoder. In this way, there can be obtained a hydraulic excavator capable of precisely measuring a stroke length of a hydraulic cylinder driving a work implement, as well as a method for measuring the stroke of the hydraulic cylinder of the hydraulic excavator.
摘要:
The invention relates to a fluidic actuator comprising a drive element (2) that can be supplied with a pressure fluid and a two-stage proportional position controller (3) controlling the supply with pressure fluid to the drive element, said actuator comprising an electro-fluidic pilot stage (10) of the position controller, exactly one electromechanical transducer (14) and exactly one proportional valve (16) actuated by said transducer and having a pressure fluid inlet (18), a control pressure outlet (19) and a discharge outlet (20). A fluidic power stage (11) of the position controller comprises two poppet valves (24, 25) having associated pressure-to-distance converters that are supplied by a common control chamber (34) which is connected to the control pressure outlet (19) of the pre-stage (10).
摘要:
The invention relates to a controlled three-way proportional valve unit comprising: a valve assembly with two individual valves; an actuating device actuating valves of the valve assembly; and a control unit acting upon the actuating device and having a control signal input, the valves of the valve assembly being designed as poppet valves arranged on opposite sides and having counter-rotatable valve spindles. The valve spindles are prestressed relative each other in opposite directions by a prestressing element such that, when the actuating unit is inactive, a first poppet valve is open and the second poppet valve is closed. The actuating device comprises an actuator common to both poppet valves, acts upon the two valve spindles and changes the position of the valve spindles counter to the effect of the prestressing element.
摘要:
A method of controlling a machine having a hydraulically actuated linkage includes lowering a load suspended by the leakage at least in part by leaking hydraulic fluid from a portion of a hydraulic actuation system, and generating a drift compensation control signal responsive to leaking hydraulic fluid. A machine includes an electronic controller in control communication with a valve, the electronic controller being configured to compensate for leakage induced drift of at least one hydraulic actuator of a machine hydraulic system by selectively commanding adjusting of the valve if drift criteria for the hydraulic system are satisfied.
摘要:
A method for controlling an air cylinder such that air is supplied to and exhausted from pressure chambers of the air cylinder by air servo valves. Pressures in the pressure chambers are detected by pressure sensors, signals of the detected pressures are feedback to a controller, and the degrees of opening of the air servo valves are adjusted by corresponding PID adjusters of the controller on the basis of the respective differences between instruction values and detection values. The displacement of the rod of the air cylinder is detected by a displacement sensor, and a detection signal of the displacement is fed back to the controller so that a gain of the PID adjuster is always changed in accordance with the detection signal of the displacement.
摘要:
This present invention relates to a remote electro-hydraulic actuator for actuating of mechanical devices, such as a valve in an internal combustion exhaust pipe. The actuator includes a multi-vane rotational assembly that flows the working fluid through strategically sized flow channels within the structure of the rotational assembly. The size of the holes are sized to help the stability of the valve and can also be provided with pressure check valves or reed valves to dampen the rotation of the valve and reduce any instabilities due to pulsations driven back via the output shaft.
摘要:
This present invention relates to a remote electro-hydraulic actuator for actuating of mechanical devices, such as a valve in an internal combustion exhaust pipe. The actuator includes a multi-vane rotational assembly that flows the working fluid through strategically sized flow channels within the structure of the rotational assembly. The size of the holes are sized to help the stability of the valve and can also be provided with pressure check valves or reed valves to dampen the rotation of the valve and reduce any instabilities due to pulsations driven back via the output shaft.
摘要:
A vehicle-height control system includes: a fluid supply and discharge device including a compressor configured to suck fluid, and a tank configured to supply the fluid; an actuator-side passage connected to the fluid supply and discharge device; a vehicle-height control actuator provided for a wheel and connected to the actuator-side passage via a vehicle-height control valve; and a vehicle height controller configured to control a vehicle height for the wheel by controlling the fluid supply and discharge device and the vehicle-height control valve to control supply and discharge of the fluid in the vehicle-height control actuator. The vehicle height controller includes a start controller configured to open the vehicle-height control valve after establishing communication between the actuator-side passage and at least one of the tank and the compressor in a state in which the vehicle-height control valve is closed at a start of control of the vehicle height.