468 results about "Shuttle valve" patented technology

The invention relates to the technical field of loader brake valves, and discloses a hydraulic brake valve and a hydraulic system thereof.The hydraulic brake valve comprises the hydraulic brake valve, the hydraulic brake valve is composed of a one-way valve, a brake valve set, a brake lamp pressure switch, a low-pressure alarm pressure switch, a shuttle valve, a high-low pressure unloading valve and a throttling hole, and the high-low pressure unloading valve and the throttling hole are integrated; a P port, an A port, a B port, a T port, an LS1 port, an LS port, a low-pressure alarm pressure switch and a brake lamp pressure switch are arranged outside the hydraulic brake valve. A liquid filling valve is omitted, an oil source of the full-hydraulic power braking system is taken from an existing priority valve CF port of equipment, pressure feedback signals are selected through a shuttle valve on a hydraulic braking valve, the pressure feedback signals are transmitted to the priority valve, and liquid filling and energy supplementing of the full-hydraulic power braking system or steering work of a steering system is achieved. The brake has the remarkable advantages of being fast in brake response, low in noise, low in failure rate, high in safety coefficient, compact in structure, low in cost and low in energy consumption.

A first output end of a two-way hydraulic pump is connected with one end of a second oil way, one end of a third oil way and one end of a first auxiliary oil way, the other end of the second oil way is connected with a left end connector of a shuttle valve, the second oil way is communicated with the third oil way, and a first hydraulic control one-way valve is installed in the third oil way; the other end of the third oil way is connected with a rodless cavity of the hydraulic cylinder, and the other end of the first auxiliary oil way is matched with one end of the second hydraulic control one-way valve. A second output end of the bidirectional hydraulic pump is connected with one end of a fourth oil way, one end of a fifth oil way and one end of a second auxiliary oil way, the other end of the fourth oil way is connected with a right end connector of the shuttle valve, the fourth oil way is communicated with the fifth oil way, a second hydraulic control one-way valve is installed in the fifth oil way, and the other end of the fifth oil way is connected with a rod cavity of the hydraulic cylinder. The other end of the second auxiliary oil way is matched with one end of the first hydraulic control one-way valve. According to the invention, the vehicle door can be automatically opened or closed.

A winch hydraulic control system includes a hydraulic oil tank, a hydraulic pump, and an electric motor. The hydraulic pump's oil inlet is connected to the hydraulic oil tank, the electric motor is connected to the hydraulic pump, and the hydraulic pump's oil outlet is connected to both port P of the main reversing valve assembly and port P of the control valve assembly. Ports A and B of the main reversing valve assembly are connected to port A of the first shuttle valve, port A of the balancing valve assembly, and port B of the control valve assembly, respectively. Port X is connected to port B of the second solenoid reversing valve. Ports B and C of the first shuttle valve are connected to port B of the balancing valve assembly and port B of the second shuttle valve, respectively. A third pressure reducing valve is connected in parallel with the second solenoid valve. Port P of the second solenoid reversing valve is connected to port X of the control valve assembly, port A of the second shuttle valve, and port SP of the balancing valve assembly. Port C of the second shuttle valve is connected to the rod chamber of the brake. The brake is connected to the hydraulic motor, and the oil outlet of the control valve assembly is connected to the oil inlet of the balancing valve assembly. This design can maintain constant wire rope tension and stable operation.

The invention discloses an unmanned mining dump truck hydraulic braking system and a control method. The unmanned mining dump truck hydraulic braking system comprises a service brake valve set and a parking brake valve set. The service brake valve group comprises a first hydraulic proportional pressure reducing valve, a second hydraulic proportional pressure reducing valve, a first shuttle valve and a first pressure sensor; the first hydraulic proportional pressure reducing valve and the second hydraulic proportional pressure reducing valve are connected in parallel; oil outlets of the first hydraulic proportional pressure reducing valve and the second hydraulic proportional pressure reducing valve are communicated with an oil inlet of a first shuttle valve; an oil outlet of the first shuttle valve is connected with a first pressure sensor; the parking brake valve group comprises an electromagnetic directional valve, a redundant electromagnetic directional valve and a pressure switch; the electromagnetic directional valve is a normally closed valve, and the redundant electromagnetic directional valve is a normally open valve; the electromagnetic directional valve and the redundant electromagnetic directional valve are connected in series, the electromagnetic directional valve is connected with an oil inlet pipeline, the redundant electromagnetic directional valve is connected with an oil outlet pipeline and a parking brake caliper, and a pressure switch is arranged on the oil outlet pipeline.

The utility model discloses a hydraulic valve group and system for controlling a power head to axially float along with threads, and relates to the technical field of hydraulic control, two oil inlets of a shuttle valve are arranged close to a third oil port and a fourth oil port and are respectively communicated with a first oil way and a second oil way, a port I of a two-position three-way manual valve is communicated with an oil drainage port, and a port II of the two-position three-way manual valve is communicated with an oil drainage port. When the two-position three-way manual valve keeps the spring position, a first port and a second port of the two-position three-way manual valve are communicated, pilot ports of the two hydraulic control one-way valve sets are connected in parallel and return oil through the first port of the two-position three-way manual valve, the two hydraulic control one-way valve sets are closed, and the two hydraulic control one-way valve sets return oil through the second port of the two-position three-way manual valve. When the two-position three-way manual valve is switched to the locking position, the third port and the second port of the two-position three-way manual valve are communicated, the pilot ports of the two hydraulic control one-way valve sets are both communicated with the second port of the two-position three-way manual valve, and the two hydraulic control one-way valve sets are opened. The service life of the power head main shaft and the drill rod can be prolonged.

The invention relates to the field of tire type walking equipment, and discloses a load-sensitive hydraulic brake valve and a load-sensitive hydraulic system thereof, and the load-sensitive hydraulic system comprises the load-sensitive hydraulic brake valve, a load-sensitive pump, a priority valve, a steering hydraulic system, a working hydraulic system, a shuttle valve and corresponding connecting pipelines; a P port, an A port, a B port, a T port, an LS1 port, an LS port, a low-pressure alarm pressure switch and a brake lamp pressure switch are arranged outside the load-sensitive hydraulic brake valve. According to the system, full-hydraulic dynamic braking can be achieved on equipment without a prefill valve, the equipment efficiency is improved, the installation cost is reduced, the energy consumption is reduced, and the service life is prolonged. Wherein the load-sensitive hydraulic brake valve integrates a brake function, a pressure maintaining function, a high-low pressure switching function, a pressure signal selection function and a pressure alarm function; the invention has the advantages of fast braking response, low noise, low failure rate, high safety coefficient, compact structure, low cost, low energy consumption and long service life.

The invention provides an impact rotary drilling hydraulic control system of a dinting machine, which belongs to the technical field of hydraulic control systems and comprises a variable pump, a pilot oil source control valve group, a proportional multi-way valve, a shuttle valve I, a one-way pressure reducing valve, a shuttle valve II, a drilling machine pilot handle group, an impact rotary drilling machine, a bidirectional hydraulic lock and a drilling machine feeding oil cylinder. According to the hydraulic control system for percussive rotary drilling of the dinting machine, the percussive rotary drilling machine can perform stepless speed regulation between two speeds, high-frequency percussive or low-frequency percussive operation can be flexibly used according to rock stratum and geological working conditions, the application range of equipment is greatly widened, and the hydraulic control system can be used for rock stratums with high hardness, weathered rock stratums and hard and brittle geology. And during low-frequency impact operation, one-key linkage operation can be realized, namely, the functions of feeding, rotating and impacting of the drilling machine can be completed by operating the impact pilot handle.

The invention discloses a valve body conduction method, which is realized through a valve body liquid control system, and comprises a one-way valve, a multi-way reversing valve, a pressure compensation valve, a first shuttle valve, a pressure reducing valve and a second shuttle valve, the method comprises the steps that the pressure reducing valve firstly gives a feedback signal, after the multi-way reversing valve is opened, hydraulic oil is supplied to the second shuttle valve through the pressure compensation valve and the first shuttle valve, and the feedback signal is obtained by comparing the oil pressure at the two ends of the second shuttle valve. The operation of the winch operating platform control system is more stable, the valve body can be better conducted, and oil is supplied to an execution element.

The utility model provides an unloading system which comprises a hydraulic pump station and a winch control system, the hydraulic pump station supplies oil to the winch control system, the winch control system drives a motor and a second motor to rotate, the winch control system comprises a first oil way and a second oil way, the first oil way drives the motor to rotate, and the second oil way drives the second motor to rotate. The second oil way drives the second motor to rotate; the first oil way comprises a first middle-position unloading valve and a first operating valve, the second oil way comprises a second middle-position unloading valve and a second operating valve, and a first unloading shuttle valve is arranged between the first oil way and the second oil way; according to the structure, when one winch needs to be started, unloading oil ways of the two winches are closed, and full-load operation of the winches can be conducted.

According to the excavator constant-speed cruise control device and method, a user presses a rocker switch to the position corresponding to the cruise direction, the rocker switch gives an electric signal corresponding to the cruise direction to a controller, the user turns on the cruise switch in the controller, the controller gives an electric signal corresponding to the opening of an oil outlet of a proportional electromagnetic valve, and the proportional electromagnetic valve is switched on. The proportional electromagnetic valve receives electric signals and outputs hydraulic oil, the hydraulic oil enters the shuttle valve and is injected into a pilot control oil way in the corresponding direction, constant-speed cruising is achieved, the cruising speed can be steplessly adjusted between zero and the maximum walking speed, walking is stable, the working intensity of a driver is reduced, and the service life of the driver is prolonged. The manual walking system and the cruise system are independent of each other and do not affect each other, safety and stability are improved, normal manual operation of walking of the excavator is not affected, installation of an existing excavator is facilitated, damage is small, and good practicability is achieved.

The utility model relates to a hydraulic system, in order to solve the problem that when an engine of an existing loader is started, an energy accumulator of a braking system is filled with liquid to increase the starting load of the engine, the hydraulic system of the loader comprises a liquid filling valve, a flow amplifying valve, a two-position three-way valve and a shuttle valve, an oil inlet of the prefill valve is connected with a CF port of a priority valve in the flow amplification valve; an oil inlet, an oil outlet and an oil return port of the two-position three-way valve are correspondingly connected with an S signal port of the prefill valve, a first oil inlet end of the shuttle valve and an oil tank loop, the oil outlet of the two-position three-way valve is selectively communicated with the oil inlet or the oil return port, and an LS1 signal port of the flow amplification valve is communicated with a second oil inlet end of the shuttle valve. And the oil outlet end of the shuttle valve is connected with a control signal port of the priority valve. The hydraulic system of the loader does not have a liquid filling load when the engine is started, and is easy to start.

The invention discloses a hydraulic leveling device, a hydraulic leveling method and an aerial work platform, and relates to the field of hydraulic control. The device comprises an electromagnetic reversing valve, a first two-way balance valve, a second two-way balance valve, a first leveling oil cylinder, a second leveling oil cylinder, a controller, a shuttle valve, a first electromagnetic unloading valve and a first pressure sensor. A first port and a second port of the shuttle valve are respectively connected with a second port and a third port of the second bidirectional balance valve, and a third port of the shuttle valve is connected with the oil return tank through the first electromagnetic unloading valve; the first pressure sensor is arranged on a pipeline between the shuttle valve and the first electromagnetic unloading valve and is used for detecting first pressure in the pipeline; and the controller is used for controlling the first electromagnetic unloading valve to be powered on and powered off according to the first pressure when amplitude variation operation is started and the initial state of the working platform is an inclined state. The problem that structural parts are damaged due to high pressure between the first leveling oil cylinder and the second leveling oil cylinder is solved.

The invention discloses a constant pressure and load sensitive switching hydraulic control system and method, and belongs to the technical field of hydraulic control, the constant pressure and load sensitive switching hydraulic control system comprises a power mechanism, a variable pump and an oil tank, the variable pump comprises a load sensitive valve, the load sensitive valve is connected with a shuttle valve outlet of a shuttle valve, and an electric proportional overflow valve is connected with the variable pump; the electric proportional overflow valve is further connected with a first inlet of the shuttle valve, a P port of the reversing valve is connected with the variable pump, and an A port of the reversing valve is connected with a second inlet of the shuttle valve; the pressure sensor assembly is used for reading the outlet pressure of the variable pump and transmitting the outlet pressure to the controller. The pressure sensor assembly is further used for reading the load-sensitive feedback pressure and transmitting the load-sensitive feedback pressure to the controller. Constant pressure and negative sensitive switching is automatically carried out along with increase of the load pressure, the load-sensitive system can be prevented from working under the low-pressure condition, and the problems that under the low-pressure condition, an execution element of the load-sensitive system is slow in action, and the system efficiency is low can be effectively solved.

The stacked type fixed differential pressure reducing valve comprises a valve body, a valve element arranged in the valve body in a sliding mode and a shuttle valve arranged at one end of the valve body, a left valve cavity is formed between one end of the valve element and the valve body, a right valve cavity spaced from the left valve cavity is formed between the middle of the valve element and the valve body, and a large-aperture oil supply channel P penetrating through the right valve cavity is formed in the valve body; the valve body is provided with a first load port A and a second load port B, the first load port A and the second load port B are communicated with the left valve cavity through the shuttle valve, and the valve element is provided with a damping structure so that the valve element can slide in the valve body in a damping mode. The large-aperture oil supply channel P is arranged, so that the device is suitable for the large-flow condition; the valve element is provided with the damping structure so that the valve element can slide in the valve body in a damping mode, the stability and precision of the pressure reducing valve can be improved, the fixed differential pressure reducing valve can move slowly even under the high pressure condition, the stability under the high pressure is further improved, and the fixed differential pressure reducing valve is suitable for the working condition of high flow.

The present application discloses a hydraulic system and an injection molding machine, which is applied to the injection molding machine and includes: a mold locking circuit and a glue injection circuit, wherein the mold locking circuit includes: a first relief valve, multiple reversing valves, a first cartridge valve, an active safety valve and a shuttle valve, which are configured to lock the mold at a preset pressure and maintain pressure; the glue injection circuit, connected to the mold locking circuit, includes: a hydraulic lock, multiple reversing valves, a proportional relief valve, a second relief valve and multiple cartridge valves, which are configured to adjust the injection speed and the melt density through the injection back pressure and the melt back pressure. The present application solves the problem of low plastic product production efficiency of the injection molding machine in the prior art.

The invention discloses an emergency valve, a hydraulic system and engineering machinery. An oil port 1 of a main overflow valve is connected with an oil port P, and an oil port 2 of the main overflow valve is connected with an oil port T; the oil port P is connected with the oil port C, the oil port 1 of the sequence valve is connected to an oil way between the oil port P and the oil port C, the oil port 2 is connected with the oil port D, and the oil port 3 is connected with the oil port T; an oil port 2 of the pressure buildup switch is connected with an oil port P and an oil inlet of the hand-operated direction valve, and an oil port 1 of the pressure buildup switch is connected with an oil port T; an oil outlet of the manual reversing valve is respectively connected with the oil port A and the oil port B; an oil port 1 of the pressure reducing valve is connected with an oil port X, an oil port 2 of the pressure reducing valve is connected with an oil port 2 of the shuttle valve, an oil port 3 of the pressure reducing valve is connected with an oil port T, the oil port 1 of the shuttle valve is connected to an oil way between an oil outlet of the hand-operated direction valve and an oil port A, and the oil port 3 of the shuttle valve is connected to an oil way between the oil outlet of the hand-operated direction valve and an oil port B; according to the invention, after an upper vehicle power system fails, the crane can realize full-action emergency and emergency collection.

The utility model discloses a TMTB high-voltage cycloid motor brake increasing device which comprises an output shaft and a shell, the output shaft rotationally penetrates through the middle of the shell, a connecting plate is connected to the side face of the shell, a rear shell is connected to the side face of the connecting plate, the output shaft is fixedly connected to a large connecting shaft, and the large connecting shaft is fixedly connected to the shell. The large connecting shaft is located in the shell, the connecting plate and the rear shell, the end of the large connecting shaft is connected with a small linkage shaft, the small linkage shaft is rotationally arranged in the rear shell, a rear partition plate is arranged between the rear shell and the stator and rotor pair, the rear partition plate is arranged on the outer side of the small linkage shaft in a sleeving mode, and a wet-type copper-based friction plate is adopted. The brake has the advantages that the belleville spring serves as a brake composition unit, the copper-based friction plate does not pollute the cleanliness of oil in the motor, the integrated shuttle valve is used in a matched mode, the brake can be released when the motor is started, synchronous braking is achieved when the motor stops running, the braking state during stopping can be effectively guaranteed, and safety and reliability are achieved.

The utility model discloses a tractor electric control lifter control system, which belongs to the technical field of tractor lifter control systems, and comprises a pressure compensation valve, a proportional reversing valve, a shuttle valve and a lifting oil cylinder, a system oil inlet is communicated with a first oil port of the proportional reversing valve, a second oil port of the proportional reversing valve is communicated with a rodless cavity of the lifting oil cylinder, and the pressure compensation valve is connected with the shuttle valve. A third oil port of the proportional reversing valve is communicated with a rod cavity of the lifting oil cylinder, and a fourth oil port of the proportional reversing valve is communicated with the oil return port; an oil inlet and a first control oil port of the pressure compensation valve are respectively communicated with a system oil inlet, an oil overflow port of the pressure compensation valve is communicated with a bypass oil port, two oil inlets of the shuttle valve are respectively communicated with a second oil port and a third oil port, and an oil outlet of the shuttle valve is communicated with a second control oil port of the pressure compensation valve. The pressure compensation valve can collect load pressure signals through the shuttle valve and can automatically adjust the flow input into a system according to the opening degree of the proportional reversing valve under various working conditions, and therefore energy waste is reduced.

The emergency falling control system comprises a manual pump, a pressure gauge and a two-position two-way manual reversing valve which are arranged on the side face of a rotary table, and the manual pump is connected with a second oil pipe, a third oil pipe, a fourth oil pipe and a fifth oil pipe and further connected with a second balance valve connected with a two-arm telescopic cylinder. The third balance valve is connected with the two-arm variable-amplitude cylinder, the fourth balance valve is connected with the one-arm telescopic cylinder, a rotary brake is arranged in the rotary table, the rotary brake is connected with a shuttle valve through a sixth oil pipe, the rotary brake is connected with a rotary motor, and a rotary cushion valve is arranged between the rotary motor and the shuttle valve. According to the emergency falling control system of the large-height overhead working truck, the manual pump is connected into the control oil way, and due to the fact that the control oil way only transmits pressure and does not transmit flow, labor is saved during operation.

The invention relates to an unmanned emergency hydraulic braking system for a mine car, which comprises a hydraulic oil tank, a hydraulic pump, an emergency braking valve, a pedal valve, two electro-hydraulic proportional braking valves and a brake, and the two oil inlet ends of the pedal valve are respectively connected with the oil inlet ends of the two electro-hydraulic proportional braking valves; the two oil outlet ends are connected with the oil outlet ends of the two electro-hydraulic proportional brake valves through the two shuttle valves respectively, and the emergency brake valve is connected with the hydraulic control end of the pedal valve. The input ends of the brakes are connected with the pedal valve and the electro-hydraulic proportional brake valve through the shuttle valve, the shuttle valve respectively compares the output pressure of the pedal valve and the output pressure of the electro-hydraulic proportional brake valve and outputs the larger pressure to the two brakes, and emergency braking under the working conditions that the pressure of the braking system is smaller than a set value and the unmanned driving system is powered off is achieved; meanwhile, the emergency brake valve is arranged, pilot control oil of the pedal valve is output according to different working conditions, and the service life of hydraulic elements of the system is prolonged under the condition that effective operation of the system is guaranteed.

The invention discloses a variable-speed hydraulic synchronous driving system with non-equivalent flow division and a working method of the variable-speed hydraulic synchronous driving system, and belongs to the technical field of hydraulic synchronous driving. Comprising a measurement and control system, a servo oil source, a dynamic pressure feedback diverter valve and a driving unit, the servo oil source, the dynamic pressure feedback diverter valve and the driving unit are connected in sequence, the driving unit comprises a first driving branch and a second driving branch, a diverter detection unit comprises a flow compensation module, and the flow compensation module comprises a valve body; the pressure compensation unit comprises a first pressure compensation valve, a second pressure compensation valve and a shuttle valve, and the dynamic pressure feedback unit comprises a spring-mass module and a damping hole which are connected in series. Flow is distributed and loads are homogenized through the load-sensitive diverter valve, the flow difference, caused by time-varying unbalance loading, of the two branches is compensated through the dynamic pressure feedback device, high-precision synchronization of the two driving branches is achieved through the non-equivalent diverter principle, and meanwhile the efficiency of the synchronous driving system is improved through variable-rotating-speed servo oil supply.

The invention discloses an electro-hydraulic drive-by-wire redundancy braking control system for controlling the braking stability of a manned and unmanned selectable tracked vehicle. The system comprises an oil supply system, independent drive-by-wire brake valve sets on the two sides, a drive-by-wire brake change-over switch valve, a mechanical hydraulic brake valve, a shuttle valve, a brake cylinder and a brake pipeline. The independent drive-by-wire brake valve sets on the two sides are connected with a left brake cylinder and a right brake cylinder respectively and used for achieving decoupling line control of left brake force and right brake force, and therefore the requirement for brake stability control is met. Meanwhile, a mechanical hydraulic brake loop is reserved in the system as redundancy, and when the drive-by-wire system breaks down, the mechanical hydraulic brake valve can output brake pressure through the shuttle valve to achieve reliable braking; through the design, the electro-hydraulic drive-by-wire redundant braking system realizes drive-by-wire decoupling of left and right braking force of the tracked vehicle and braking stability control, and ensures the braking reliability under a fault condition, so that the driving safety of the tracked vehicle is greatly improved.

The utility model discloses a double-stop-valve control structure which is characterized in that a stop valve block is arranged on a rear cover of an axial plunger closed type pump, an A-port working oil way stop valve is arranged in the stop valve block, and a B-port working oil way stop valve is arranged in the rear cover; oil drainage of the A-port working oil way stop valve and oil drainage of the B-port working oil way stop valve share one oil drainage channel, A-port working oil enters the A-port oil way stop valve through an A-port channel arranged in the rear cover, and B-port working oil enters the A-port oil way stop valve through a B-port channel arranged in the rear cover. Different cut-off pressures can be set for the working oil port A and the working oil port B of the hydraulic axial plunger closed type pump according to needs, and the hydraulic axial plunger closed type pump can cope with more complex working conditions. The oil port A and the oil port B can be independently adjusted more conveniently, meanwhile, the structure of the stop valve sleeve is optimized, the length is shortened, parts such as a shuttle valve and an ejector pin are omitted, cost is reduced, and convenience is created for manufacturing of the stop valve sleeve.

The invention belongs to the field of electro-hydrostatic actuators, and particularly relates to an electro-hydrostatic actuator structure with a high servo characteristic and a control method. Comprising a servo motor, a hydraulic pump, a hydraulic control one-way valve, a shuttle valve, an electromagnetic valve, a pressure sensor, an actuator cylinder and a controller. The servo motor is mechanically connected with the hydraulic pump, hydraulic control one-way valves are connected between the actuating cylinder and an oil inlet and outlet path of the hydraulic pump, and the pressure of remote control ports of the two hydraulic control one-way valves is switched through the two electromagnetic valves. The pressure sensors measure the pressure of the two cavities of the actuator cylinder and transmit the pressure to the controller. The two inlets of the shuttle valve are respectively communicated with the two cavities of the actuating cylinder to select the high-pressure side pressure in the oil cavity of the actuating cylinder; and the controller controls the rotating speed and the torque of the servo motor after receiving the position instruction, the motor state parameters and the data of the pressure sensor. According to the electro-hydrostatic actuator, the rotating speed overshoot of the hydraulic pump in the starting process can be reduced, and the servo characteristic of the electro-hydrostatic actuator is improved.

The present invention provides a hydraulic oil tank, an oil pump, a directional control valve assembly, a liquid charging valve, an accumulator, a foot brake valve, a front axle shuttle valve, a front axle brake cylinder and a rear axle brake cylinder. A multi-circuit hydraulic braking mode is adopted, including three braking modes: normal braking, emergency braking and parking braking. The hydraulic oil output by the oil pump can be directed to different circuits according to different braking modes. Under normal braking, dual-circuit braking is adopted, so that braking can be performed even when one hydraulic circuit fails, thereby ensuring safety and making braking more reliable.

The utility model discloses an electro-hydraulic steer-by-wire redundant system which comprises a one-way valve, a hydraulic control reversing valve, a pressure reducing valve, a proportional reversing valve, a steering gear, shuttle valves, a hydraulic control one-way valve and a steering oil cylinder, the shuttle valves comprise a first shuttle valve and a second shuttle valve, and the proportional reversing valve is electrically connected with a control center unit. The input ends of the one-way valve and the pilot operated directional valve are connected with a high-pressure oil port P of the oil tank through pipelines respectively, the output end of the one-way valve is connected with the proportional directional valve and the steering gear respectively, the steering gear is connected with the steering oil cylinder, the proportional directional valve is connected with the pilot operated directional valve and the first shuttle valve respectively, and the pilot operated directional valve is connected with the steering oil cylinder. The second shuttle valve is connected with the steering gear and the pressure reducing valve, the pressure reducing valve is connected with the hydraulic control reversing valve to control steering of the hydraulic control reversing valve, and the proportional reversing valve and the steering gear are connected with an oil tank T port.

The main and standby integrated passive electric control brake valve comprises a main brake valve and an auxiliary brake valve, the main brake valve and the auxiliary brake valve share one control box, an oil storage cup and an oil pipe connector, and oil cavities of the main brake valve and the auxiliary brake valve are both communicated with the oil outlet end of the oil storage cup; a self-return shuttle valve is arranged between the main brake valve and the auxiliary brake valve, and an oil passing cavity is formed in the self-return shuttle valve; a steel ball is arranged in the oil passing cavity in a sliding mode and can block the paths, flowing to the oil pipe connector, of oil in the main brake valve and the auxiliary brake valve, and elastic damping pieces are arranged at the ends, close to the oil inlet direction of the main brake valve and the auxiliary brake valve, of the steel ball. The elastic damping part is arranged to counteract hydraulic force in the pressure reduction process, so that the steel ball cannot block a communication path of the main brake valve oil cavity and the oil passing cavity during pressure reduction, hydraulic oil can flow back to the main brake valve, and the oil pumping fault can be avoided.

The invention discloses a quick-closing type linear electro-hydraulic actuator with an automatic pressurizing function. The quick-closing type linear electro-hydraulic actuator comprises an oil tank, a hydraulic control one-way valve, a hydraulic pump, an anti-explosion motor, an overflow valve, a shuttle valve, an anti-explosion pressure sensor, a pressure gauge, an anti-explosion electromagnetic valve, an energy accumulator, a hydraulic lock, a hydraulic oil cylinder and an anti-explosion displacement sensor. The hydraulic system adopts a closed loop, oil is supplemented for flow deviation caused by an asymmetric cylinder through a hydraulic control one-way valve, stretching and retracting of an oil cylinder are achieved by controlling the rotating direction of a motor, a reversing valve does not need to be installed for high-pressure and low-pressure oil way switching, the number of electromagnetic control valves is small, the structure is simple, and control is convenient. The actuator is quickly reset in a power-off state by adopting an energy accumulator oil supply mode, a manual pump or a reset spring does not need to be installed, and the energy accumulator can be automatically pressurized after the pressure of the energy accumulator is reduced. A displacement sensor is installed on the oil cylinder for position feedback, and accurate position control of the oil cylinder can be achieved by adjusting the rotating speed of the motor.

A high-lift forklift, and a hydraulic control system and method based on single-pump oil supply. The system comprises a load-sensitive pump (1), a hydraulic oil tank, a priority valve (3), an LS-type liquid filling valve (12), a steering gear (2), a brake valve (5), a brake accumulator (6), a first shuttle valve (13), and a second shuttle valve (11), wherein an oil outlet of the load-sensitive pump (1) is connected to each of a P port of the priority valve (3) and a P port of the LS-type liquid filling valve (12), a CF port of the priority valve (3) is connected to a P port of the steering gear (2), an EF port of the priority valve (3) is connected to a multy valve, and a port A of the LS type liquid filling valve (12) is connected to both the brake valve (5) and the brake accumulator (6); and an LS port of the LS-type liquid filling valve (12) is connected to a first shuttle valve (13), the first shuttle valve (13) is connected to each of an LS port of the priority valve (3), an LS port of the steering gear (2) and the second shuttle valve (11), and the second shuttle valve (11) is connected to an LS port of the load-sensitive pump (1). The problem of engine shutdown or failure when creating a pressure level required for normal operations caused by rapid pressure increments when oil liquid that is fed back by a steering system continuously drains at a medium position in a standby state is avoided.

The invention discloses a dual-pump confluence load-sensitive valve group and a multi-way valve for engineering machinery, and provides a modular integrated design, the valve group comprises an oil inlet valve plate I, a confluence valve plate, a reversing valve plate and an oil inlet valve plate II, the oil inlet valve plate I is integrated with a priority valve core and an overflow valve, and oil return through a short path of the confluence valve plate during neutral-position unloading of an oil pump I is realized; a three-way flow adjusting valve is arranged in the second oil inlet valve plate and is in linkage with the shuttle valve through an LS2 / LS3 channel, and the oil supply state and the unloading state of the second oil pump are dynamically switched. The converging valve plate controls double-pump converging logic through the reversing valve rod, P1 and P2 converge to a working port A through a logic one-way valve under the lifting working condition, meanwhile, an LS2 channel feeds back load pressure to trigger a three-way valve to be closed and unloaded, and rapid large-flow response is achieved. The unloading oil way structure is optimized, the pressure loss path is shortened, the flow requirement is accurately matched in combination with load sensitive control, the meso-position unloading energy consumption is reduced, the problems of energy waste and response lag of a traditional system are solved, the energy efficiency of equipment is remarkably improved, and the service life of the equipment is remarkably prolonged.