2898 results about "Reversing valve" patented technology

The invention discloses a device for measuring flowability of explosive modeling powder, which comprises a step-press-loading analogue unit, a timing and weighing unit and a computer control unit, wherein the step-press-loading analogue unit directly and indirectly drives a screw rod which extends into a blanking bin to rotate and perform reciprocating movements along an axial line and drives a pusher dog in the blanking bin to perform the reciprocating movements along an arc section through the combined action of a cylinder and a pneumatic reversal valve so as to ensure that the explosive modeling powder in the blanking bin falls into the timing and weighing unit, and the process more truly imitates an explosive conveying process of an explosive step-press process. The timing and weighing unit transmits a weighing value of the explosive modeling powder which falls in the timing and weighing unit to the computer control unit in real time, and the computer control unit calculates the instantaneous flow speed of the explosive modeling powder of a north side and generates a flow speed-time curve according to sampling data. The device can measure the flowability of the explosive modeling powder so as to provide an objective basis for choosing a proper explosive step-press process for the explosive modeling powder.

The invention relates to the technical field of electric vehicle power battery thermal management, and discloses a temperature change-based power battery thermal management system, which comprises a thermal simulation pre-judgment end, a sensor network end, a dynamic liquid cooling control end, a BMS decision end and a fault diagnosis module, aiming at the technical defects of out-of-control temperature difference, response hysteresis and leakage risk caused by static flow channel design of the existing liquid cooling system, breakthrough is realized through a three-dimensional technical architecture: a CFD (Computational Fluid Dynamics) prejudgment layer: automatically calibrating sensor distribution points based on temperature field standard deviation, and improving temperature difference identification precision; according to the dynamic valve control layer, an electromagnetic three-way reversing valve is adopted to execute a directional temperature control strategy, an edge battery cell is preferentially introduced under the low-temperature working condition, and heat dissipation is enhanced under the high-temperature working condition; according to the redundant safety layer, the valve body and the pipeline are integrally formed, the leakage rate is reduced, and flow maintenance under single-point failure is achieved through a double-water-inlet parallel pump source. The method has the effects of improving the convergence speed of temperature difference between modules, reducing the attenuation rate of battery life and reducing the risk probability of thermal runaway.

The invention relates to the technical field of liquid cooling heat dissipation, in particular to a liquid cooling distribution device, liquid cooling heat dissipation equipment and a liquid cooling control method. The liquid cooling distribution device comprises a main liquid supply collecting pipe, a flow adjusting assembly, a multi-channel liquid distribution assembly, a plurality of cooling medium conveying pipelines and a central control unit, a proportioning valve of the flow adjusting assembly is connected into the main liquid supply collecting pipe in parallel, and a liquid distributor of the multi-channel liquid distribution assembly is correspondingly connected with the proportioning valve. A parallel branch of the liquid separator is connected with the liquid outlet node through the reversing valve, and the two ends of the cooling medium conveying pipeline are connected with the liquid outlet node and target heat dissipation equipment respectively; the central control unit achieves accurate distribution and dynamic adjustment of the flow of the cooling liquid by controlling the proportion adjusting valve and the reversing valve, the problem of uneven flow distribution caused by pipeline resistance difference is solved, the flow can be adjusted according to real-time heat loads, and system energy consumption is optimized.

The invention discloses a load simulation loading system based on an engineering mechanical power system and a control method thereof, and relates to the technical field of mechanical power system simulation. The load simulation loading system comprises an engineering machinery power system, a load loading system, a whole vehicle control unit and an upper computer platform. The engineering machinery power system comprises a first oil tank, a main pump, a pilot pump, a pilot control handle, a signal control valve and a multi-way valve. The load loading system comprises a three-position four-way reversing valve, a proportional overflow valve, a first proportional throttle valve, a second proportional throttle valve, an electromagnetic valve, a third proportional throttle valve and a variable pump, wherein the three-position four-way reversing valve, the proportional overflow valve and the first proportional throttle valve are connected to the multi-way valve, the second proportional throttle valve and the electromagnetic valve are connected to an outlet of the proportional overflow valve, and the third proportional throttle valve is connected between the second proportional throttle valve and the second oil tank. And the three-position four-way reversing valve is constructed to enable an inlet of the proportional overflow valve to be communicated with one of the oil port A and the oil port B of the multi-way valve in a switching manner, and an outlet of the proportional overflow valve to be communicated with the other one of the oil port A and the oil port B in a switching manner.

A constant-flow control valve group, an auxiliary arm control module, a complete hydraulic system, and a crane. The constant-flow control valve group comprises: a cartridge valve; a cartridge reversing valve, comprising a working oil port on one side and a main oil return port and a reversing valve oil inlet selectively connected to the working oil port on the other side, the working oil port being connected to a control oil port of the cartridge valve, and the reversing valve oil inlet being connected to a main oil inlet of the cartridge valve; and a feedback on-off valve, disposed in a working feedback oil path connected between the main oil inlet of the cartridge valve and a main feedback oil port of the constant-flow control valve group. The auxiliary arm control module comprises the constant-flow control valve group and a main reversing valve. The complete hydraulic system comprises the auxiliary arm control module and an auxiliary arm luffing cylinder, and may further comprise a load-sensitive oil pump and a main valve. The present application can achieve the effect of directly connecting an auxiliary arm hydraulic system to an existing complete hydraulic system as a sub-module without altering the original system.

The invention relates to the technical field of valve bodies, and provides a pressure reducing valve with emergency shutoff and backflow prevention functions, which comprises a main valve body, a main valve membrane and a valve core assembly, the main valve body comprises a valve cavity with a water inlet end and a water outlet end, and the main valve membrane is arranged in the valve cavity and divides the valve cavity into a control cavity and an overflowing cavity; the pressure reducing valve is in a pressure reducing dynamic adjusting state, when the pressure reducing valve is in the pressure reducing dynamic adjusting state, the shut-off reversing valve changes the position so as to close the pressure reducing pilot valve to be communicated with the water outlet end, and the pressure reducing valve is switched to an emergency shut-off state so as to be closed. When the pressure reducing valve is in the pressure reducing dynamic adjusting state, the anti-backflow reversing valve changes the position to close communication between the water inlet end and the control cavity and enable the water outlet end to communicate with the control cavity, and the pressure reducing valve is switched to be in the anti-backflow state so as to be closed. The problem that in the prior art, downstream leakage or backflow of a traditional pressure reducing valve cannot be blocked in time is solved.

The utility model discloses an electro-hydraulic reversing valve which comprises a pilot electromagnetic valve and a main valve. The pilot electromagnetic valve is detachably connected with the main valve; after the pilot electromagnetic valve is connected with the main valve, an oil cavity in the pilot electromagnetic valve is communicated with an oil way in the main valve; a first pilot control oil way, a second pilot control oil way, an outer oil supply way, an inner oil supply way, an outer oil discharge way and an inner oil discharge way in the main valve are all casting oil ways, and the number of each oil port is two. The oil paths in the main valve are all formed through casting instead of auxiliary holes, so that the impact resistance of the oil paths can be improved, oil leakage at conical plugs of the auxiliary holes is avoided, the pressure loss of hydraulic oil flowing in the oil paths can be reduced, and the through-flow capacity of the hydraulic oil in the oil paths is improved.

The utility model discloses a converter station resin replacement system based on the negative pressure jet principle, which comprises a booster pump, a reversing valve, a resin particle bin, an ion exchanger, a water suction pump and a particle recovery bin, an inlet of the booster pump is communicated with a water source through a first valve, and an outlet of the booster pump is communicated with an inlet of the reversing valve through a pipeline provided with a pressure gauge. An outlet of the reversing valve is communicated with an upper inlet of the ion converter through a first pipeline, the first pipeline is communicated with the resin particle bin through a pipeline provided with a second valve, a lower outlet of the ion converter is communicated with an inlet of the water suction pump through a second pipeline, and an outlet of the water suction pump is communicated with the particle recovery bin through a pipeline; most old resin particles are driven to be discharged out of the ion exchanger through high-speed jet flow, air in the new resin storage bin is taken away through the high-speed jet flow, negative pressure is formed to enable the new resin particles to be entrained and sucked into the pipeline, a mixture of the resin particles and water is conveyed into the ion exchanger, and filling of the new resin particles in the ion exchanger is achieved.

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 a pulse-free hydraulic reciprocating fluid material conveying pump which comprises a pump body, a pulse adjusting assembly and a reversing valve. The pump body is connected with the two slurry cylinders, and slurry suction and discharge ports of the slurry cylinders are connected with the slurry suction and discharge valve assembly; a slurry suction port of the slurry suction and discharge valve assembly is connected with the main liquid inlet pipeline, and a slurry discharge port of the slurry suction and discharge valve assembly is connected with the main liquid discharge pipeline; a pulse adjusting assembly is arranged between the oil inlet pipe and the main liquid discharging pipeline, slurry discharging compensation is provided by arranging the pulse adjusting assembly when the oil cylinder is at a reversing point of reciprocating motion, the stability of the slurry discharging flow is guaranteed, and under the condition that a pressure reducing valve is arranged, blockage removing can be conducted on the slurry discharging pipeline by adjusting the pressure reducing valve to be normal and increasing the pressure in the slurry discharging pipeline.

The utility model relates to the field of hydraulic braking, and discloses a parking braking system and agricultural machinery, the parking braking system comprises a parking brake, a first reversing valve, a second reversing valve and an energy accumulator, a working oil port of the first reversing valve is connected with a rod cavity of a brake cylinder of the parking brake, an oil inlet of the first reversing valve is connected with an oil inlet path, and an oil outlet of the second reversing valve is connected with an oil outlet path; an oil return port of the first reversing valve is connected with an oil return path, in a power-off state, a working oil port of the first reversing valve is communicated with the oil return port, an oil outlet of the second reversing valve is connected with the oil return path, in the power-off state, an oil inlet of the second reversing valve is communicated with the oil outlet, and the energy accumulator is connected with the oil inlet of the second reversing valve. According to the parking braking system, the situation that tires are locked when the agricultural machine loses power accidentally in the running process can be avoided, and meanwhile the agricultural machine can be slowly and stably decelerated till the agricultural machine is stopped and parked.

An automobile thermal management system comprises a refrigerant circulating system, a cabin cooling liquid circulating system and a passenger cabin cooling liquid circulating system which are connected with one another, a four-way reversing valve component is adopted in an agent side module or assembly, and a water path system is simplified while the agent side loop reversing function is achieved through a plate heat exchanger; compared with the prior art, the number of the water valves is greatly reduced, so that high quality risks such as inner leakage, heat leakage and high mode switching frequency caused by the quality of the water valves are reduced, and the quality risks are greatly reduced after the water valves are simplified.

The present invention discloses a pneumatically controlled, high-pressure, balanced sewage, two-position, three-way reversing ball valve structure, comprising: a valve seat, a valve ball, and a valve ball centering sleeve installed within a valve body; the valve seat having three openings: a left opening and a right opening, located at the left and right ends of the valve seat, respectively, and a center opening located in the center of the valve seat; a port A located on the left side of the valve body, communicating with the center opening of the valve seat; a port B located on the right side of the valve body, communicating with the right opening of the valve seat; a high-pressure water wellhead connector connected to the left end of the valve body, the port of the high-pressure water wellhead connector being port P, forming a chamber C within the high-pressure water wellhead connector; a feedback piston sealing sleeve forming a closed chamber D at the right end of the feedback piston; chambers C and D being connected via a balancing pipe. The valve valve has reliable sealing performance, requires relatively low water cleanliness, and can be used in sewage reversing valves; it also features fast response speed and high flow rate.

The invention discloses gas-liquid mixed transportation supercharging equipment for a compressor, and belongs to the technical field of supercharging equipment, the gas-liquid mixed transportation supercharging equipment comprises a gas-liquid supercharging cylinder, a power cavity is arranged in the gas-liquid supercharging cylinder, oil change ports are arranged on the power cavity and located on two sides of a driving piston, and supercharging cavities are arranged on the gas-liquid supercharging cylinder and located on two ends of the power cavity. A sealing block is arranged between the pressurizing cavity and the power cavity; a driving piston is slidably connected into the power cavity. A driven piston is slidably connected into the pressurizing cavity; by controlling the reversing valve group, flexible switching of the oil flow direction is achieved, bidirectional movement of the driving piston can be achieved without a complex mechanical structure, the system structure is simplified, the manufacturing cost is reduced, the reliability of equipment is improved, and the response speed of the equipment is increased. Meanwhile, by means of high efficiency and stability of hydraulic transmission, stable operation of the driven piston in the pressurizing cavity is guaranteed, and stable and efficient work of the whole hydraulic system is guaranteed.

The utility model relates to the technical field of all-steel-ball type electromagnetic multi-way valves of harvesters, and discloses an all-steel-ball type electromagnetic multi-way valve of a harvester, which comprises a composite hydraulic control plunger, the composite hydraulic control plunger comprises a second steel needle, a sealing element and a second guide column, the sealing element comprises a third steel ball and a second ball seat, and the second steel needle is connected with the second steel needle. A second ball seat is connected into the second guide column, one end of the second ball seat is connected with a third steel ball, one end of a second steel needle is connected with the third steel ball, the third steel ball is used for blocking the opening A1, the other end of the second steel needle is connected with a combined hydraulic control plunger, the combined hydraulic control plunger is slidably connected into the control chamber f, and the oil inlet chamber h is communicated with the oil return chamber g. The opening A1, the cavity j, the oil inlet chamber h, the oil return chamber g and the oil return channel T1 are sequentially communicated. According to the all-steel ball type electromagnetic multi-way valve of the harvester, all reversing valves are composed of double-ball type pilot valves and steel ball type hydraulic control one-way valves. The anti-pollution capacity is extremely high, and the reliability is high.

The invention relates to the technical field of oil exploitation equipment, in particular to an oil reservoir pressurizing device which comprises a plurality of setting devices arranged on the outer wall of a sleeve shell in the axial direction of the sleeve shell, the outer walls of the setting devices are attached to the well wall of a water injection well, the space between the sleeve shell and the well wall is divided into a first gap and a second gap, and the first gap corresponds to an oil reservoir low-permeability layer; the second gap corresponds to an oil reservoir high-permeability layer; the shunting mechanism comprises a first nozzle communicated with the first gap and a second nozzle communicated with the second gap; and the hydraulic flow conversion part communicates with the reversing valve, the first nozzle and the second nozzle, and the hydraulic flow conversion part has a first state of introducing gel into the second nozzle, a second state of introducing gel into the first nozzle and a third state of introducing high-pressure water into the first nozzle and the second nozzle. The problem that a high-permeability layer is not blocked thoroughly or a low-permeability layer is excessively polluted is effectively solved.

The utility model discloses a hydraulic logic control system for a sidesway distance adjusting fork. Comprising an oil pump, a safety valve, a first reversing valve plate, a logic control valve block, a first hydraulic control one-way valve, a first three-way pipe, a right pallet fork distance adjusting oil cylinder, a left pallet fork distance adjusting oil cylinder, a first overload valve, a second hydraulic control one-way valve, a second three-way pipe, a third three-way pipe, a third hydraulic control one-way valve, a throttling valve, a second reversing valve plate and a second overload valve. The logic control valve block comprises a second hydraulic control one-way valve, a third hydraulic control one-way valve, a throttling valve and a second overload valve, and the second hydraulic control one-way valve, the third hydraulic control one-way valve, the throttling valve and the second overload valve are communicated through pipelines. And the first reversing valve plate is communicated with the second reversing valve plate. According to the hydraulic logic control system for the laterally-moving distance adjusting fork, the purpose of hydraulic oil way regulation and control is achieved through the arrangement of the structure.

The invention relates to the technical field of turnover plow hydraulic control, in particular to a turnover plow hydraulic control system and method, and the structure of the turnover plow hydraulic control system comprises a main control valve; the main valve communicates with the main control valve, and a throttling opening is formed in the end of the main valve; the first reversing valve is communicated with the main valve; the second reversing valve is communicated with the main valve; a large cavity of the amplitude modulation oil cylinder is communicated with the second reversing valve, and a small cavity of the amplitude modulation oil cylinder is communicated with the first reversing valve; a large cavity of the overturning oil cylinder is communicated with the first reversing valve, and a small cavity of the overturning oil cylinder is communicated with the second reversing valve; the pilot valve is communicated with the throttling opening of the main valve; the amplitude modulation oil cylinder and the overturning oil cylinder can be locked with each other and act in sequence. According to the hydraulic control system and method for the turnover plow, the problem that an existing turnover plow is complex to control can be solved.

The utility model discloses a reusable vacuum container, which comprises a volume-variable container, a pump, a reversing valve, a fixed liquid outlet nozzle and a fixed liquid inlet nozzle, and is characterized in that the reversing valve is provided with a liquid inlet / outlet, a first liquid outlet, a second liquid outlet, a first liquid inlet and a second liquid inlet; a flow channel in the reversing valve is switched in a manner that when liquid is taken, the first liquid inlet is communicated with the first liquid outlet and is cut off from the liquid inlet and outlet, and the second liquid outlet is communicated with the liquid inlet and outlet and is cut off from the second liquid inlet; when liquid is supplemented, the first liquid inlet is communicated with the liquid inlet and outlet and is cut off from the first liquid outlet, and the second liquid outlet is communicated with the second liquid inlet and is cut off from the liquid inlet and outlet. Due to the fact that the vacuum container is provided with the pump and the reversing valve, and the reversing valve can change the flow direction of the pumped fluid, the fluid can be pumped out of the vacuum container and can also be pumped into the vacuum container, and the purpose that the vacuum container can be refilled with the fluid to be reused is achieved.

The invention belongs to the technical field of hydraulic control, and particularly relates to a steering mechanism, a control method of the steering mechanism and an operation machine.The steering mechanism comprises an axle, a steering wheel and a hydraulic control system, and the hydraulic control system comprises a power-assisted steering oil cylinder used for driving the axle to execute steering operation; the oil supply path is used for supplying oil to the power-assisted steering oil cylinder; the electric control reversing valve is arranged on the oil supply way, and two working oil ports of the electric control reversing valve are communicated with a rod cavity and a rodless cavity of the power-assisted steering oil cylinder respectively; the control unit is in communication connection with the electric control reversing valve and is configured to determine the turning angle of an axle under the condition that it is determined that the driver does not place the two hands on a steering wheel; and the working position of the electric control reversing valve is switched according to the turning angle, so that the power-assisted steering oil cylinder drives the axle to return, and the steering wheel is driven to return. By the adoption of the steering mechanism, when the two hands of a driver leave the steering wheel, the power-assisted steering oil cylinder can be automatically controlled to drive the axle and the steering wheel to return.

The invention relates to the technical field of design of an air suction prevention scheme for a hydraulic rocker gear oil cooling circulating pump of a coal mining machine, in particular to an air suction prevention method for the hydraulic rocker gear oil cooling circulating pump of the coal mining machine and the coal mining machine. Aiming at the problem of air suction damage of a circulating pump caused by change of the inclination angle of the rocker arm, oil suction ports are formed in the lowest liquid level positions of the positive and negative inclination angles of the rocker arm respectively, the inclination angles are monitored in real time through an angle sensor, and an electric control box controls an electric proportional reversing valve to act according to inclination angle signals and drives a hydraulic control reversing valve to be switched to a corresponding working position. And the gear oil circulating pump is always communicated with the current lowest liquid level oil suction port. According to the scheme, the pumping air corrosion risk is thoroughly eliminated, the service life of the pump body and the gear set is prolonged, and meanwhile system energy consumption is reduced. According to the preferable scheme, the filter and the cooler are integrated to form a closed-loop purification cooling loop, and the cleanliness and the thermal stability of the oil are further guaranteed. According to the invention, the adaptability defect of the fixed oil suction port under the dynamic dip angle working condition is overcome, and reliable guarantee is provided for high-load continuous operation of the coal mining machine.

A HVAC&R system includes a heat pump configured to selectively circulate a working fluid. The heat pump includes an outdoor heat exchanger, an indoor heat exchanger, a compressor, a reversing valve configured to direct the working fluid from the compressor to the outdoor heat exchanger or to the indoor heat exchanger, and a controller. The controller is configured to determine whether a pressure of the working fluid exiting the compressor exceeds a pressure threshold, and, in response to determining that the pressure of the working fluid exiting the compressor exceeds the pressure threshold, control the reversing valve to block the working fluid from flowing from the compressor through the reversing valve to the outdoor heat exchanger.

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 invention relates to the technical field of valves, and discloses a two-position four-way reversing valve which comprises a double-spliced valve body and a hydraulic pushing device. Two hydraulic cavities which are communicated with each other are formed in the double-spliced valve body, a valve element is arranged in each hydraulic cavity, and a through hole which extends axially is formed in each valve element; a liquid inlet, a liquid return opening and a liquid outlet which are communicated with the hydraulic cavity are formed in the double-spliced valve body; the valve element is sleeved with a valve sleeve, a first flow channel is formed in the position, opposite to the liquid inlet, of the valve sleeve, and a second flow channel is formed in the position, opposite to the liquid return opening, of the valve sleeve. By arranging the valve sleeve outside the valve element, inlet and outlet liquid can flow through the first flow channel or the second flow channel firstly, so that the effective flow area of high-pressure liquid entering the cavity of the double-spliced valve body from the liquid inlet is remarkably increased, and the flow of the inlet and outlet liquid is remarkably increased; and the reliability and the response speed of position switching of the valve element in the valve cavity are ensured.

The application provides a two-position five-way pneumatic reversing valve, and relates to the technical field of hydraulic control valves.The valve body is provided with a first air outlet hole, an air hole and a second air outlet hole from left to right on the lower side, and the inner cavity of the valve body is provided with a valve core.The left end of the valve body is provided with a front baffle, and the right side of the valve body is provided with a piston assembly, which is in contact with the right end surface of the valve core.The valve body is provided with a first annular protrusion, a second annular protrusion, a third annular protrusion, a fourth annular protrusion and a fifth annular protrusion corresponding to each hole.The outer side of the air hole is provided with a plug A, and the air hole is connected with the piston assembly through a pipeline arranged in the valve body.The pipeline is internally provided with a plug B.The electromagnetic structure of the application is integrated, and the parts have better coaxiality during production and assembly, effectively ensuring the service life of the product and the extremely low product failure rate.Compared with the existing split structure, the application has higher electromagnetic conversion efficiency and can effectively reduce the power consumption of the product.

The utility model provides an interactive paddling table, which relates to the field of entertainment equipment and comprises a shipway, a traction device and a pedal reversing plate, and the traction device and the pedal reversing plate are positioned at the front end of the shipway; the traction device comprises a traction rope, a rotating wheel and a first sensor, the rotating wheel is connected with the traction rope, and the first sensor is arranged on the rotating wheel; the pedal reversing plate comprises a pedal plate and a reversing valve arranged on the pedal plate. Thus, the traction device is used for controlling the speed, the pedal reversing plate is used for controlling the direction, and compared with an interactive paddle table of a double-paddle structure, the interactive paddle table does not need to reserve enough paddle space when being installed, and the occupied space of the interactive paddle table is reduced.

The invention relates to the technical field of drilling, and provides a roofbolter feedforward-feedback model-free adaptive tracking control method and system based on rotation force. According to the method, a valve-controlled hydraulic propulsion control model for driving a hydraulic cylinder and a corresponding reversing valve in the working process of the hydraulic jumbolter is established, and a nonlinear autoregressive moving average model between the propulsion force in the working process of the hydraulic jumbolter and the output driving current of the reversing valve is obtained through the valve-controlled hydraulic propulsion control model; through a nonlinear autoregression moving average model of the hydraulic jumbolter, an output identification observer deployed with a data-driven adaptive control algorithm of the hydraulic jumbolter is established, and the output identification observer performs adaptive tracking control on the working state of the hydraulic jumbolter through the deployed data-driven adaptive control algorithm. The tracking control problem of the valve control electro-hydraulic servo unit under the complex working condition is effectively solved.

The invention belongs to the technical field of injection molding machine mold closing systems, and particularly relates to an injection molding machine movable mold plate position control hydraulic system. A movable mold plate position control method is applied to a movable mold plate position control hydraulic system of an injection molding machine and comprises the following steps: a pressure building step: supplying oil to a rod cavity of a pressure oil cylinder, closing a main valve, retracting a piston rod, driving a movable mold plate to move, and entering a pressure maintaining stage after a preset value is reached; oil supply to the rod cavity is stopped, the first electromagnetic reversing valve is controlled to be powered on, oil of the pilot control oil way flows through the liquid resistance network, and pressure is released through the liquid resistance network to guarantee that a valve element of the main valve is stable and free of impact; the piston rod is pulled to extend out, the oil in the rod cavity is decompressed, and oil is supplemented to the rodless cavity; and adjusting the position of the movable template: controlling a reversing valve group to switch on and off an oil path, and enabling the pressure oil cylinder to be in differential connection so as to adjust the position of the movable template.

A gas-fired heat pump unit that directly utilizes engine waste heat and features adjustable air supply is disclosed. The condenser and water supply and return lines are combined with refrigerant and coolant heat exchange lines. Refrigerant flows from the quasi-two-stage compressor outlet through the refrigerant heat exchange line, dividing it into a main path and an auxiliary path. The auxiliary path connects to the quasi-two-stage compressor air supply port after passing through a first electronic expansion valve and a flue gas heat exchanger. The main path, switched by a four-way reversing valve, can control forward and reverse circulation between the second electronic expansion valve and the outdoor evaporator. The outlet is connected to the quasi-two-stage compressor inlet. Coolant flows from the gas engine outlet through a coolant circulation pump and the coolant heat exchange line back to the inlet. The gas engine exhaust port is connected to the flue gas heat exchanger. Compressor air supply is simple and highly adjustable. The condenser utilizes stepped heating to decouple engine waste heat from compressor power. Heating is continuous during reverse cycle defrosting, improving indoor thermal comfort.

A directional control valve provided with a plurality of external flow channel ports for fluid entry and exit. A flow channel switching assembly is further arranged inside the directional control valve and configured to provide different internal flow channels in different switching positions, so as to connect different external flow channel ports. The flow channel switching assembly comprises: a movable valve member (121), which is provided with a plurality of movable valve member flow channels (1211), wherein at least one movable valve member flow channel penetrates the body of the movable valve member and connects different external flow channel ports located on two sides of the movable valve member; and a fixed valve member (122), which is provided with a plurality of fixed valve member flow channels, wherein the movable valve member abuts against the fixed valve member; the movable valve member can be driven to rotate around a first axis to switch positions; and in the different switching positions, different movable valve member flow channels and fixed valve member flow channels form different internal flow channels so as to connect different external flow channel ports.