603 results about "Electrohydraulic servo valve" patented technology

The invention relates to a servo valve test system. By adopting a cartridge valve to automatically switch static and dynamic oil lines, the servo valve test system can realize the full automatic one-step test and intelligent analysis of the static properties and the dynamic properties of an electro-hydraulic servo valve, improves the test efficiency of the electro-hydraulic servo valve, and increases the accuracy of the test results. Strictly based on the test standard of the electro-hydraulic servo valve GB / T15623-1995, the whole test method completes all the detection tests of the servo valve, and automatically displays and outputs the test results. The servo valve test system mainly comprises a hydraulic test system, an electrical control system and a data acquisition and processing system, wherein a servo valve to be tested is connected with the hydraulic test system and the electrical control system; a main oil line of the hydraulic test system is automatically switched to the dynamic oil line and the static oil line by a cartridge valve assembly, and the hydraulic test system is also provided with a dynamic cylinder for detecting the servo valve to be tested; and the data acquisition and processing system is connected with the electrical control system and the hydraulic test system.

The invention discloses a crane device and a compensation method with a multi-degree-of-freedom active wave compensation function in the field of marine ships. The lower part is a circular static platform fixed on the deck; The moving platform is fixedly connected to the crane. Six servo cylinders are connected between the circular static platform and the circular moving platform. Each of the six servo cylinders is connected to a corresponding electro-hydraulic servo valve. The electro-hydraulic servo valves are serially connected in series Connect the power amplifier and D / A module to the motion controller, and the attitude sensor is installed in the center of the circular static platform; the attitude sensor transmits the measured roll, pitch and heave values ​​of the ship caused by wind and waves to the motion control The motion controller first obtains the motion values ​​of the six servo cylinders, and then obtains the wave compensation value opposite to the motion value. The six electro-hydraulic servo valves output the corresponding flow and pressure according to the wave compensation value to control the corresponding six Servo cylinders telescopic and sway to compensate for roll, pitch and heave.

The invention relates to an airplane electrical signal transmission brake antiskid control system. When brake is carried out, an electro hydraulic servo valve can not output brake pressure, a control box emits a control signal to an electromagnetic hydraulic lock, the electromagnetic hydraulic lock unlocks by energization, the hydraulic power source is switched on, and the brake is carried out on a brake machine wheel with maximum brake pressure. During a brake process, if the machine wheel slips, the control box controls the electromagnetic valve for energization to release pressure. The system is simple and easy to be carried out, the reliability and security of the brake system operation can be greatly increased during taking off, landing rollout processes, the work load of a driver is reduced, even the electro hydraulic servo valve generates fault, the tire burst can be effectively avoided, and the airplane usage safety is ensured.

The invention discloses a digital electrohydraulic control system of a steam turbine with isolated network operation, comprising a control hardware part and a software logical operation part, wherein the control hardware part includes a speed measuring protection part, a one-time frequency modulation module, a servo control module, a man-machine interface part, a control unit and an input / output module; and the software logical operation part includes a first frequency modulation operation and secondary frequency modulation operation unit based on frequency deviation, an overspeed limit unit based on an actual rotating speed measuring signal and a logical judgment unit based on an actual power measuring signal. The control system carries out logical processing and operation on the frequency deviation and outputs a control signal to control an electrohydraulic servo valve through the servo control module to drive a servomotor so as to drive a valve to move, thereby controlling the steam admission quantity of the steam turbine to keep the balance between the output of a steam turbine generator unit and the receiving load of the steam turbine generator unit; in addition, the speed measuring protection part takes an accelerated speed signal as a trigger condition of overspeed limit, thereby effectively limiting the rotating speed overshoot generated by the steam turbine generator unit because of load shedding.

The invention provides a control method and a system for nozzle changeable turbocharger, which relates to an electric control system of a nozzle changeable turbocharger with an electrohydraulic servo ratio electromagnetic valve as an executor. The invention is characterized in that based on the acquired rotate speed of an engine and the acquired position signal of an accelerator pedal, a target boost pressure value and a target position driving signal value are worked out; and a control algorithm of the PWM signal value used to drive the electrohydraulic servo valve adopts an open loop feedforward control with the optimum position of the electromagnetic valve as the a control target, and a closed loop digital PI feedback control with a boost pressure in an air inlet pipe as a control target. In order to improve the control precision and the response speed of the control system, the control parameters of the closed loop PI control is obtained by checking up a two-dimensional MAP graph according to the rotate speed signal of the engine and the position signal of the accelerator pedal. Compared with the prior pneumatic control system, the electric control system has quick control response speed; and, compared with the control system in which a step motor is used as the executor, the executor of the invention has the advantages of big output torque and high precision.

A measuring and controlling system of an electro-hydraulic servo valve comprises a hardware part and a software part, wherein the hardware part comprises sensors, an acquisition card, a signal conditioning circuit and a computer; the software part comprises three test modules which are respectively of an electro-hydraulic servo valve static characteristic module, and a PID closed-loop control module and an electro-hydraulic servo valve dynamic characteristic module. Firstly, signals of the sensors pass through a hardware conditioning circuit and then are subjected to the A / D (Analog to Digital) conversion through the acquisition card to be converted into digital signals; signals compiled by the software are subjected to the D / A (Digital to Analog) conversion through the acquisition card and then serve as control signals of the servo valve; test functions are realized through all modules in a program; the measuring and controlling system has the advantages that the environment of the measuring and controlling system is effectively improved, the test cost of the electro-hydraulic servo valve and the impact of the personal factors are reduced, operation steps are greatly simplified, and the accuracy and efficiency of testing are improved.

A control valve includes a main poppet that moves in response to pressure in a primary control chamber and thereby controls the flow of fluid through a valve seat between first and second ports. A passageway extends between the second port and the primary control chamber and includes a variable flow restriction that decreases as the main poppet moves away from the valve seat. An electrohydraulic pilot valve has a pilot poppet which controls fluid flow from the primary control chamber to the first port in response to pressure in a pilot control chamber. A sub-pilot valve selectively releases pressure in the pilot control chamber to operate the pilot poppet to open and close a path between the inlet and the outlet. Using an electrohydraulic pilot valve enables the main poppet to operate quickly in controlling large fluid flow rates. Unidirectional and bidirectional versions of the control valve are described.

The invention relates to a mixed airplane brake system and a control method. A brake valve of the mixed airplane brake system is connected to a airplane pressure supply system, an electro hydraulic servo valve oil inlet and an oil returning tank through a pipeline; the electro hydraulic servo valve is connected to a brake nozzle of the brake valve, an oil inlet of the electromagnetic valve and an airplane oil return tube through the pipeline; and an electromagnetic hydraulic lock and the electro hydraulic servo valve are parallel channels on a hydraulic line. An oil inlet pressure transducer is arranged on the pipeline between the brake valve and the electro hydraulic servo valve; a brake port pressure transducer is arranged on the pipeline between the electromagnetic valve and a brake machine wheel. Under the failure of the electro hydraulic servo valve, an airplane antiskid brake control system can automatically convert a current normal brake mode to a standby brake mode and then enables reliable operation, driver intervention is not required, so that the work load of the driver is reduced. The mixed airplane brake system enables mode record on a fault state of the electro hydraulic servo valve, and is convenient for troubleshooting and maintenance by maintainer after flight.

A solenoid operated valve has a valve body with a plurality of ports and a spool slideable within the valve body to interconnect the ports in different combinations. An actuator drives the spool into several operating positions. The actuator has a solenoid assembly with an armature that moves within a bore in response to an electromagnetic field. A push member projects from the armature and has a bearing secured thereto. The bearing has a cage that retains a plurality of rollable elements in slots separated by walls that are resilient enabling the rollable elements to be forced into the slots during assembly and thereafter be captured in the cage when the walls return to their original positions. A latch on the cage engages the push member to affix the bearing in place.

A method and system for controlling a solenoid-operated pressure regulator valve to achieve high compliance with respect to a commanded current in accordance with a precalibrated transfer function. A dither frequency imposed on applied current is changed at precalibrated regulated pressure values to avoid dynamic instability.

An electrohydraulic valve has a valve body with a longitudinal bore and a cylindrical exterior surface. An annular recess extends around the cylindrical exterior surface and the first port extends from the recess to the bore. A filter is formed by a plate that has a plurality of perforations and which is wrapped around valve body in the recess. The plate has a first end section at which a first tab is created and a second end section overlapping the first end section with a slot through which the first tab extends to secure the first and second end sections together. A spool is slideable into different positions within the bore of the valve body to selectively connect and disconnect the first port and a second. An actuator is operably coupled to move the spool into different positions within the bore.

The invention discloses an all hydraulic wheel type field information collecting platform which comprises a vehicle body structure, a hydraulic device and a field information collecting and control system. Sickle type self-balance mechanisms are adopted for the vehicle body to carry high arm supporting walking wheels. A gasoline engine is directly connected with a hydraulic pump to generate hydraulic pressure to achieve four-wheel driving and steering control, and a straight-plugging type hydraulic energy port is reserved. A structured vehicle-mounted computer and a structured data collection card system are matched with an angle sensor, a photoelectric sensor, a vision sensor, a satellite positioning receiver, an electronic compass, an electro-hydraulic servo valve and the like to conduct collecting, analyzing of field parcel information, crop information and state information of itself and subsequent auto-walking control. The all hydraulic wheel type field information collecting platform is compact in structure, a high ground clearance is used so that the field passing capability is good, the walking stability is high, the carrying capability is high, and a foundation platform is provided for developing vision navigation, satellite positioning navigation, soil interaction key part testing, sowing and fertilize applying key part testing and field information collection.

The invention discloses a multipoint loading fatigue tester controlled by a microcomputer, which relates to a material tester and mainly solves the problems of fatigue tests of samples with large volume and high precision requirement in the construction of highways and railway bridges. The tester comprises a host machine, a loading mechanism, a measuring system, a hydraulic system and a control system, wherein the host machine comprises a stand and an attachment on the stand; a moving cross beam is arranged at the upper part of the bearing stand; a bearing cross beam is arranged at the lower part of the bearing stand; the bearing stand is provided with a cushion block; a sample is arranged on the cushion block; a servo loading oil cylinder used as the loading mechanism is arranged between the moving cross beam and the sample; the measuring system is provided with a sensor and a display; the hydraulic system is provided with a hydraulic oil cylinder, an electrohydraulic servo valve, a pipeline and the like; and the control system mainly comprises a microcomputer system. Various test work can be finished by combining the systems and the main machine. The invention can realize a multipoint synchronous pressure-resistant fatigue test and is used for fatigue tests of full-size steel beams, combined beams and concrete beams and pressure-resistant fatigue tests of welding joints, reinforcing steel bars, guy cables and hanger rods.

The invention pertains to a hydraulic servo-control technology, relating to an improvement on the operating principle of traditional hydraulic servo valves. The novel intelligent piezoelectric electro-hydraulic servo valve mainly comprises a closed-loop piezoelectric ceramic drive, a slide valve spool, a valve pocket, a left end cap and a right end cap, a device which prevents the rotation of the spool, a valve pocket centering piece and a piezoelectric ceramic drive seat. The closed-loop piezoelectric ceramic drive can export thrust force and pulling force in a high-frequency manner, and the sensor of closed-loop piezoelectric ceramic drive can detect the displacement of the high-frequency vibration output; the closed-loop piezoelectric ceramic drive is directly connected with the slide valve spool fixedly so as to drive the spool to make high-frequency reciprocating movements. The device which prevents the rotation of the spool can prevent the slide valve spool from rotation, and as a result, the piezoelectric ceramic drive is protected from damage due to the axial rotary force. The null position of the spool adopts the valve pocket to adjust the centering piece. The novel intelligent piezoelectric electro-hydraulic servo valve breaks the bottleneck that the bandwidths of traditional electro-hydraulic servo valves are relatively small, and the invention can operate in a high-frequency and high-precision manner; thereby, the high-frequency and high-precision performance of the novel intelligent piezoelectric ceramic material can be sufficiently applied to the field of hydraulic servo control.

A solenoid operated valve has a valve body with a plurality of ports and a spool slideable within the valve body to interconnect the ports in different combinations. An actuator drives the spool into several operating positions. The actuator has a solenoid assembly with an armature that moves within a bore in response to an electromagnetic field. A push member projects from the armature and has a bearing secured thereto. The bearing has a cage that retains a plurality of rollable elements in slots separated by walls that are resilient enabling the rollable elements to be forced into the slots during assembly and thereafter be captured in the cage when the walls return to their original positions. A latch on the cage engages the push member to affix the bearing in place.

A fuel circuit for an aviation turbine engine, the fuel circuit including: a main fuel line for feeding fuel to a combustion chamber of the engine and including a positive displacement pump; an auxiliary fuel line connected to the main fuel line at a junction situated downstream from the pump and serving to feed fuel to hydraulic actuators to control variable-geometry equipment of the engine, the auxiliary fuel line including electrohydraulic servo-valves upstream from each actuator; and a fuel pressure regulator valve arranged on the main fuel line downstream from the pump.

The invention relates to an airplane braking system for preventing an emergency brake from being improperly used. The airplane braking system comprises a normal braking system and an emergency braking system, wherein the normal braking system comprises a braking command sensor, an electromagnetic hydraulic lock, an electromagnetic servo valve, a control box and an airplane wheel speed sensor; the emergency braking system comprises an emergency braking valve, a converting valve and a switch; and the normal braking system and the emergency braking system are contacted and converted through the converting valve. According to the airplane braking system disclosed by the invention, during emergency braking, if normal braking is also used, the normal braking system is forced to release pressure, so that pressure does not exist in a normal input opening of the converting valve, the situation that the converting valve is completely converted to the emergency braking system is guaranteed, the application of the emergency braking is guaranteed, and emergency braking failure and accident hidden danger caused by that the emergency braking and the normal braking are used at the same time are eliminated fundamentally; and according to the airplane braking system disclosed by the invention, only one electrical switch element is additionally arranged on a conventional braking system, so that conventional equipment is convenient to refit.

The invention discloses a method for controlling the random vibration of an electrohydraulic servo system based on RLS filters, which comprises the following steps: converting an acceleration power spectral density reference signal into an acceleration time domain driving signal; taking an acceleration input signal of the electrohydraulic servo system as that of an RLS filter I; online regulating weights of the RLS filter I and an RLS filter II in real time by using an RLS adaptive filter algorithm and performing identification on a frequency response function of the electrohydraulic servo system and an impedance function of the RLS filter I respectively; and constructing a filter III based on the identification result of the impedance function of the RLS filter II, filtering the acceleration time domain driving signal and taking an output signal of the filtration as the acceleration input signal of the electrohydraulic system. The convergence property of the RLS adaptive filter algorithm adopted by the method guarantees the convergence property of the real-time online iteration of acceleration power spectral density when the characteristics of the electrohydraulic servo system and a test piece are changed.

A method for operating an electrohydraulic valve initially derives a characterization value that denotes how magnetic hysteresis affects valve operation. Upon receiving a command that designates a desired magnitude of electric current to be applied to the electrohydraulic valve, that command is modified based on the characterization value to compensate for the magnetic hysteresis. The modified command then is employed to apply electric current to the electrohydraulic valve.

A pollution and abrasion test system for an electro-hydraulic servo valve comprises four parts: a power source, an oil pollution degree control part, an electro-hydraulic servo valve mounting table and a system oil pollution degree detection part, wherein the power source part provides source power for the whole test system, the oil pollution degree control part is directly connected at the back of the power source part of the system, and controls the working oil pollution degree in test, the electro-hydraulic servo valve mounting table part is connected between a pollution level control part and the system oil pollution degree detection part, the system oil pollution degree detection part is connected with a return circuit of the system, that is between the electro-hydraulic servo valve mounting table and a system oil tank. The system is used for carrying out pollution and abrasion test on the electro-hydraulic servo valve, avoiding test error caused by particles pollution, the pollution degree of the test system is stabled in the pollution degree condition required by the test, the real-time monitoring to the pollution degree is achieved, the real-time adjustment is realized, and the test system is high in reliability, stable to operate, and easy to operate.

An electrohydraulic valve has a valve body with a longitudinal bore and a cylindrical exterior surface. An annular recess extends around the cylindrical exterior surface and the first port extends from the recess to the bore. A filter is formed by a plate that has a plurality of perforations and which is wrapped around valve body in the recess. The plate has a first end section at which a first tab is created and a second end section overlapping the first end section with a slot through which the first tab extends to secure the first and second end sections together. A spool is slideable into different positions within the bore of the valve body to selectively connect and disconnect the first port and a second. An actuator is operably coupled to move the spool into different positions within the bore.

An airplane hydraulic brake system comprises a hydraulic brake valve, a liquid-controlled conversion valve, an electro-hydraulic servo valve, an anti-slide control box and a speed sensor. The liquid-controlled conversion valve is mounted on a downstream hydraulic pipeline of the hydraulic brake valve, the electro-hydraulic servo valve is mounted on a downstream hydraulic pipeline of the liquid-controlled conversion valve, an electrical interface of the electro-hydraulic servo valve is electrically connected with the anti-slide control box through a shielding insulation wire, an oil inlet of the electro-hydraulic servo valve is in pipeline connection with an oil outlet of the liquid-controlled conversion valve, a brake opening of the electro-hydraulic servo valve is in pipeline connection with an oil inlet of a brake device of a brake airplane wheel, and an oil returning opening of the electro-hydraulic servo valve is in pipeline connection with an airplane oil returning pipeline through a hydraulic filler neck and a guide pipe. The airplane hydraulic brake system can meet the ever-growing airplane take-off line brake requirement, is reasonable in structure, easy and convenient to implement, and beneficial for reducing of burdens of a driver, conforms to the man-machine engineering principle and meanwhile the accident potentials caused by false-operation switching on of a take-off line brake switch are eliminated.

The invention provides an electrohydraulic servo bending machine hydraulic system which has a simple structure, convenience for speed control of an oil cylinder and strong generality. In the electrohydraulic servo bending machine hydraulic system, a liquid filling valve is connected between an oil tank and an upper cavity of the oil cylinder; an oil outlet of an oil pump is assembled with the oil tank through pressure control valves; a port P of a proportional servo valve is connected with the oil outlet of the oil pump; a port B is connected with a lower cavity of the oil cylinder through electromagnetic reversing valves; a port A is connected with the upper cavity of the oil cylinder; a port T is connected with the oil tank; the port P for controlling a control valve of the liquid filling valve is connected with the oil outlet of the oil pump; the port T is connected with the oil tank; and one of the port A and the port B is connected with a control oil port of the liquid filling valve, and the other port is closed.

A control valve includes a main poppet that moves in response to pressure in a primary control chamber and thereby controls the flow of fluid through a valve seat between first and second ports. A passageway extends between the second port and the primary control chamber and includes a variable flow restriction that decreases as the main poppet moves away from the valve seat. An electrohydraulic pilot valve has a pilot poppet which controls fluid flow from the primary control chamber to the first port in response to pressure in a pilot control chamber. A sub-pilot valve selectively releases pressure in the pilot control chamber to operate the pilot poppet to open and close a path between the inlet and the outlet. Using an electrohydraulic pilot valve enables the main poppet to operate quickly in controlling large fluid flow rates. Unidirectional and bidirectional versions of the control valve are described.

The invention discloses a semi-active variable-stiffness energy dissipation and seismic mitigation control anchor bolt. The anchor bolt consists of a controller (1), a communicating line (2), a sensor (3), a variable-stiffness control device (12), a sleeve (20), a hollow anchor pipe (5), an anchor gear (10), an anchoring spring (11) and a support structure (4), wherein the variable-stiffness control device (12) consists of a hydraulic cylinder (13), a dual-striking piston (14), oil (16), a bypass pipeline (17), an electro-hydraulic servo valve (18), a stiffness spring (19a), a stiffness spring (19b), and a support box (21) and a base plate (22) connected through a bolt (23). According to the semi-active variable-stiffness energy dissipation and seismic mitigation control anchor bolt, the unrecoverable problems of excessive deformation of an anchoring and shotcreting support structure, unavailable self-adjustment of the support structure, even damages and the like caused by seismic actions are solved, and the seismic resistance of the anchoring and shotcreting support structure and the safety stability of a support body are improved.

Flapper assemblies for torque motors of electrohydraulic valves are provided. The flapper assembly comprises a flapper having an upper end portion configured for coupling to an armature and armature-flapper support of the torque motor and a lower end portion having a socket therein. A hemispherical closure member having a flat diametrical face configured to seal against a nozzle outlet is disposed for oscillatory movement in the socket. A retaining clip is slidably mounted about the lower end portion and has a retention opening exposing the flat diametrical face and sized to retain the hemispherical closure member in the socket. The torque motor comprises the armature coupled to the armature-flapper support, the flapper assembly, and a plurality of coils. The electrohydraulic valve comprises the torque motor and a nozzle configured to be in fluid communication with the flapper assembly when the electrohydraulic valve is in an open position.

The invention is applicable to the servo control filed and provides a servo controller and an electro-fluid servo system. The servo controller comprises a closed-loop control unit used for adopting the PIDF control algorithm to generate driving signals according to the received control signals and feedback signals, a servo valve driving unit used for controlling the movement of an external servo device according to the driving signals generated by the closed-loop control unit, a single chip setting unit used for conducing the parameter setting on the closed-loop control unit, and a power supply unit used for supplying the power to the closed-loop control unit, the servo valve driving unit, and the single chip setting unit. In the invention, the closed-loop control unit adopts the PIDF control algorithm, a PID adjuster is utilized to realize the automatic control gain, the single chip setting unit is utilized to simply, flexibly, and precisely adjust the gain parameters, Therefore, the real-time performance and the interchangeability of the servo controller are improved.

The invention discloses an intelligent electrohydraulic flow servo valve. The intelligent electrohydraulic flow servo valve is characterized in that: a servo power (SP) and a servo valve controller (SVC) are arranged in a top cover of the electrohydraulic flow servo valve; a dry permanent magnet torque motor, and a baffle assembly is arranged on a valve body; a double nozzle flapper is connected with a high-pressure oil cavity, an overflow cavity, and control cavities at two ends of a force feedback centering slide valve through an oil path respectively; the force feedback centering slide valve is connected with the high-pressure oil cavity, a load cavity and an oil return cavity through the oil path respectively; the baffle assembly of the dry permanent magnet torque motor is connected with a feedback rod and the force feedback centering slide valve; an iron core of a linear variable differential transformer (LVDT) is connected with the force feedback centering slide valve; an SPS position transmission circuit is directly fixed on the side of a coil framework of the LVDT; and the high-precision LVDT, and the SPS position transmission circuit are arranged in an outer cover on one side of the valve body.

The invention provides a three-stage electro hydraulic servo valve controller which comprises a signal input and feedforward controller, a position closed loop unit, a speed feedback controller and a proportion controller, a servo valve drive unit and a valve core displacement output unit; wherein, the signal input and feedforward controller is used for outputting an instruction signal of a valve controller; a servo valve core displacement signal is used as a feedback signal of the position closed loop control of a servo valve and is subtracted from the instruction signal; the speed feedback controller and the proportion controller are used for improving the frequency width of the servo valve by adjusting the speed feedback gain and the proportion controller gain; the servo valve drive unit is used for generating a servo valve drive signal to drive the servo valve to act; and the servo valve core displacement signal is regulated to form a standard plus minus 10V signal, on the one hand the servo valve core displacement signal is used as the position closed loop control of the servo valve, and on the other hand the servo valve core displacement signal is output to a computer to be used for real-time monitoring after voltage-current conversion. The three-stage electro hydraulic servo valve controller adopts the speed feedback controller and the feedforward controller and develops the dynamic response frequency width of a three-stage electro hydraulic servo valve.