614 results about "Proportioning valve" patented technology

A multi-way valve includes a valve seat and a valve core. The valve core is rotatably disposed in the valve seat, the valve seat is provided with a plurality of valve port groups, each valve port group includes a plurality of valve ports, the valve core is provided with communication structure groups corresponding to the valve port groups, respectively, and each of the communication structure groups further includes a plurality of communication structures arranged along a circumferential direction of the valve core. When the valve core is rotated to different rotation positions, valve ports in different valve port groups form different communication states. Only one valve core is required to make a two-way proportional valves, three-way proportional valve, and a four-way proportional valve achieve different communication states, with simple control, compact structure and low cost.

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 trencher based on improvement of excavating equipment, which is characterized in that an original excavating working device is detached from an upper body of an original excavator, and a trenching device is additionally arranged on the upper body of the original excavator; the ditching device comprises a supporting arm frame and a ditching chain. The supporting arm frame is connected with the original upper machine body and rotationally provided with a driving wheel set and a tensioning wheel set. The trenching chain is arranged on the driving wheel set and the tensioning wheel set in a sleeving mode so as to conduct continuous trenching operation; the original engine-hydraulic power system is additionally provided with a ditching driving motor, and the ditching driving motor is connected with a driving wheel set; the ditching driving motor realizes rotary driving and stopping actions of the ditching chain through an original movable arm oil cylinder confluence oil way in the original engine-hydraulic power system and is additionally connected with a pilot valve for control; the original left and right track driving oil ways are respectively connected with the small-flow proportional valves, the small-flow proportional valves are respectively connected with the original left and right track driving oil ways in parallel, a small part of hydraulic power is shunted from the original main pump oil way, the trencher is driven to crawl at a low speed during trenching operation, and the trencher can move while trenching during operation.

The invention discloses a heavy truck hydraulic retarder control method and system and a vehicle, and belongs to the technical field of retarder control. The method comprises the steps that the target braking torque value of a retarder is read; if the target braking torque value is larger than or equal to the maximum output torque value, the target braking torque value is set to be the maximum output torque value; if yes, the target braking torque value is dynamically compensated; calculating a target working pressure value of the retarder cavity; and the deviation between the target working pressure value of the retarder containing cavity and the current working pressure and the deviation between the proportional valve target and the actual current are calculated, calculation is conducted through a PID controller, and the output serves as the input of the retarder proportional valve so as to control the output torque of the retarder. According to the invention, the output torque delay can be reduced so as to improve the braking performance of the retarder, the braking precision and stability are relatively high, and relatively stable braking can be maintained under the conditions of different vehicle speeds and different oil temperatures.

The invention relates to the technical field of unmanned aerial vehicle power systems, in particular to a low-altitude unmanned aerial vehicle hydrogen-electricity hybrid energy management system and control device.According to the low-altitude unmanned aerial vehicle hydrogen-electricity hybrid energy management system and control device, the residual hydrogen amount can be accurately quantified through combined collection and fusion calculation of hydrogen flow signals and air pressure signals; and the opening state of the proportional valve and the air inlet valve is adjusted in real time under data driving, so that the hydrogen input is matched with the actual power requirement, the voltage, the current and the temperature are synchronously monitored, and fluctuation feature extraction and life parameter calibration are performed on a power output sequence. The operation health degree and the life loss trend of the fuel cell can be dynamically obtained before power distribution, an accurate reference basis is provided for follow-up power allocation, the internal resistance change trend is measured and calculated through voltage and current sampling, and dynamic adjustment of the charge-discharge depth and charge-discharge process parameters is carried out in combination with the health degree. And the usability and the load capacity of the lithium battery are accurately represented.

In one example, a proportioning valve, comprises a valve body, a first fitting coupled to the valve body, a second fitting coupled to the valve body, and a third fitting coupled to the valve body, where the second fitting and the third fitting each extend in parallel to the first fitting. In one example, an inner bore of the valve body is substantially cylindrical. In one example, the first fitting is an outlet fitting, the second fitting is a first inlet fitting, and the third fitting is a second inlet fitting. In another example, the first fitting is an inlet fitting, the second fitting is a first outlet fitting, and the third fitting is a second outlet fitting. In one example, the valve body includes a flow diverter positioned within the valve body.

The invention provides a hydraulic driving system capable of adaptively controlling the rotating speed of a cooling fan of a rail engineering vehicle, which is characterized in that an oil outlet of a hydraulic plunger variable pump is connected with one end of a pressure pipe connected with a hydraulic motor, and the other end of the pressure pipe is communicated with an oil inlet of a temperature control proportional valve group; one oil outlet of each temperature control proportional valve group is communicated with an oil return pipe through a hydraulic oil radiator, the oil return pipe is communicated with a hydraulic oil tank, and two branches of the oil return pipe are respectively communicated with the other oil outlets of the two temperature control proportional valve groups; a safety protection structure connected with the hydraulic motor in parallel is arranged on the pressure pipe, and the hydraulic plunger variable pump is connected with the flow adjusting structure. The system overcomes the defects that when a traditional switching value valve set controls on-off of the cooling fan, system pressure impact is large, and huge noise is generated, system power is dynamically matched in real time according to the heat dissipation requirement, safe operation of a vehicle is ensured, impact force of instant starting and stopping of the cooling fan is reduced, the noise generated by the cooling fan is weakened, and the service life of the vehicle is prolonged. And the traction available power of a vehicle power system is improved.

A hydraulic braking arrangement for controlling front brakes and rear brakes of an off-road vehicle includes a hydro-mechanical service brake system fluidly connecting front and rear brakes to a first source of fluid in pressure by means of a mechanical input which may be imparted by a driver of said off-road vehicle. The hydraulic braking arrangement also includes an additional service brake system fluidly connecting front and rear brakes to a second source of fluid in pressure by means of an electro-hydraulic proportional valve and a remote input.

The invention discloses an electromagnetic clutch type hydraulic retarder, and particularly relates to the technical field of hydraulic retarders, the electromagnetic clutch type hydraulic retarder comprises a retarder body and a control module, the control module is connected with an electromagnetic clutch, an electromagnetic air proportional valve, a water temperature sensor, an oil temperature sensor and a pressure sensor through wire harnesses, the water temperature sensor is installed on a cooling water outlet pipeline of the heat exchanger, the pressure sensor and the electromagnetic air proportional valve are installed above the oil supplementing tank, the electromagnetic clutch is located between the driving gear and the transmission shaft, the driving gear and the transmission shaft are coaxially connected with the electromagnetic clutch, the transmission shaft is fixedly connected with the rotor, and the stator is fixed to the shell. Combination or separation of the driving gear and the rotor is achieved through the electromagnetic clutch, a floating ball valve, a forced lubrication structure and a stator and rotor disengagement structure are omitted, and the electromagnetic clutch has the advantages of being low in no-load power loss, fast in response, free of the oil injection phenomenon, simple in structure, low in failure rate, low in cost and weight and the like.

The dumper lifting system with the automatic discharging mode comprises a hydraulic oil tank, a lifting pump, a lifting proportional valve and a lifting oil cylinder and further comprises a controller, the input end of the controller is connected with a lifting angle sensor, a mode selection module, a lifting control module and a safety belt module, the lifting angle sensor is connected with the lifting oil cylinder, and the mode selection module is connected with the lifting control module. The mode selection module is a manual mode selection module and an automatic mode selection module, the output end of the controller is connected with a lifting proportional valve, a brake control module and a warning indicator, and the brake control module is connected with a vehicle brake. Through cooperative use of the mode selection module and the lifting control module, the manual operation mode and the automatic operation mode are completed, the automatic discharging mode of lifting discharging-top-reaching keeping-container falling is achieved, in the automatic discharging process, the safety of the system is monitored in real time, the mode can be switched to the manual mode at any time according to the actual situation, and the safety of the system is guaranteed. And the use safety of the system is ensured.

The utility model discloses a hydraulic system with a movable arm floating regeneration function and an excavator, and belongs to the technical field of engineering machinery. The defects that in a traditional excavator movable arm control system in the prior art, when an operator continuously controls a movable arm, fatigue is prone to being generated, and the working effect is affected are overcome. The main structure of the hydraulic system comprises a main pump, a pilot pump, a movable arm descending proportional valve, a movable arm lifting proportional valve and a movable arm oil cylinder, an oil outlet of the main pump is connected with the movable arm oil cylinder through a movable arm reversing valve, and an oil outlet of the pilot pump is connected with oil inlets of the movable arm descending proportional valve and the movable arm lifting proportional valve. An oil outlet of the movable arm descending proportional valve is connected with a right pilot oil port of the movable arm reversing valve, an oil outlet of the movable arm lifting proportional valve is connected with a left pilot oil port of the movable arm reversing valve, and a regeneration control assembly is further arranged between a rod cavity and a rodless cavity of the movable arm oil cylinder. The utility model is mainly applied to engineering machinery such as excavators and the like.

The invention discloses a fuel cell system and a control method thereof. The fuel cell system is applied to a vehicle and comprises a hydrogen supply component, an air supply component, an electric pile, a water segregator and a heat management component. The hydrogen supply component comprises a hydrogen storage mechanism, a pressure reducing valve, a plate heat exchanger, a proportioning valve and an ejector; the air supply component comprises an air filter, an air compressor, an intercooler and an inlet butterfly valve; the plate heat exchanger and the intercooler are arranged in an attached mode, an air flow channel of the intercooler is connected with the air compressor and the inlet butterfly valve, and a cooling liquid flow channel of the intercooler is connected with a low-temperature heat dissipation loop of the vehicle. The electric pile is connected with the ejector, the inlet butterfly valve and the outlet butterfly valve; the water segregator is respectively connected with the electric pile, the ejector, the nitrogen discharge valve and the water discharge valve; the heat management component is connected with a cooling liquid inlet and a cooling liquid outlet of the electric pile respectively, and the heat management component is used for forming a high-temperature heat dissipation loop of the vehicle. According to the embodiment of the invention, the operation reliability of the fuel cell system in a low-temperature environment can be improved.

The invention discloses a general aero-engine high-altitude environment simulation device, and relates to the technical field of aviation tested engine tests, the general aero-engine high-altitude environment simulation device comprises a fresh air system, a refrigerating unit and a tested engine, the output end of the fresh air system is provided with a connecting pipeline, and one side of the connecting pipeline is provided with the refrigerating unit communicated with the interior of the connecting pipeline; an air inlet and outlet proportional valve is arranged on the inner side wall, close to the refrigerating unit, of the connecting pipeline, a pipeline heating device is arranged on the outer wall, close to the air inlet and outlet proportional valve, of the connecting pipeline, and a first pressure stabilizing tank is arranged on the side, away from the pipeline heating device, of the connecting pipeline. According to the device, through cooperative control of the intake and exhaust proportional valve and the vacuum pump unit, precise simulation that the pressure fluctuation range is smaller than or equal to + / -1% and the temperature deviation is smaller than or equal to + / -1 DEG C at the height of 0-12000 meters is achieved, and the airworthiness certification standard is met.

The invention provides a deviation rectification control method for controlling autonomous walking of a hydraulic chassis based on a PLC. The deviation rectification control method comprises the following steps that S1, signals of obstacles around a crawler chassis are collected; s2, calculating the shortest distance from the geometric center of the chassis to the two sides of the roadway and the included angle between the shortest distance and the geometric center line of the advancing direction based on the signals of obstacles around the crawler chassis; s3, according to the shortest distance from the chassis geometric center to the two sides of the roadway and the included angle between the chassis geometric center and the geometric center line in the advancing direction, the offset distance and the included angle between the geometric center line in the chassis advancing direction and the roadway center line are calculated; s4, the current posture of the chassis is judged based on the offset distance and the included angle between the chassis advancing direction geometric center line and the roadway center line; and S5, controlling the corresponding hydraulic proportional valve based on the current posture of the chassis. According to the invention, the problem that a hydraulic crawler chassis does not have the functions of autonomous walking and obstacle avoidance in a mine underground operation roadway is solved; and the auxiliary operation vehicle can walk in the roadway in a self-correcting manner.

The utility model belongs to the technical field of valves, and discloses a bidirectional inverse proportion flow valve. The bidirectional inverse proportional flow valve comprises a valve sleeve, a proportional valve element, an electromagnetic driving assembly and a compensation valve element. A valve port A and a valve port B are formed in the valve sleeve. One end of the proportional valve element is arranged in the valve sleeve and provided with a valve element hole, and fluid can flow to the valve port B through the valve port A and the valve element hole in sequence or flow to the valve port A through the valve port B and the valve element hole in sequence. The electromagnetic driving assembly is assembled on the valve sleeve and used for pushing the proportional valve element to axially move in the valve sleeve. The compensation valve element is arranged in the valve sleeve and can move in two directions in the axial direction of the valve sleeve under the action of the pressure difference between the valve port A and the valve port B. The bidirectional inverse proportion flow valve provided by the utility model can realize bidirectional inverse proportion adjustment and pressure compensation, so that the bidirectional inverse proportion flow valve can be applied to occasions requiring bidirectional proportion adjustment and pressure compensation, and is wide in application scene and high in universality.

The invention discloses a self-adaptive parameter control system and method for a halfpace field rice transplanter based on full-hydraulic transmission, particularly relates to the technical field of hydraulic parameter control, and aims to solve the technical problem of dynamic power competition between a walking system and a planting device when the full-hydraulic transmission rice transplanter works in a halfpace field. Working pressure signals of a walking motor and a planting device are monitored in real time, the divergence degree of envelope lines of the two pressure signals is calculated so as to recognize the power competition state of a system, and when power competition is detected, the required power of two execution mechanisms is dynamically calculated, and a hydraulic pump displacement distribution coefficient is generated; and then the interaction characteristics of the outlet pressure of the main pump and the output flow signal and the transmission characteristics of the pressure signal of the executing mechanism are fused, the dynamic balance degree of the system is generated, the displacement distribution coefficient is corrected, and finally the opening degree of the walking motor and the proportional valve of the planting device is synchronously adjusted based on the corrected coefficient. Accurate distribution and dynamic balance control of the power of the hydraulic system are achieved.

The invention belongs to the technical field of high-pressure pump sealing, and particularly relates to a static sealing structure between a plunger sleeve and a valve seat. The sealing device is located between an oil outlet valve seat and a plunger sleeve and comprises an annular sealing ring inside the upper end face of the plunger sleeve and an annular supporting ring outside the upper end face of the plunger sleeve. The lower end face of the oil outlet valve seat is a plane, the side face of the annular sealing ring is a convex arc face, and the oil outlet valve seat and the annular sealing ring form a non-conformal single-arc-face sealing structure or a conformal contact double-arc-face sealing structure. The sealing device is suitable for high-pressure large-flow hydraulic elements and hydraulic systems, high-frequency-response electro-hydraulic servo valves and proportional valves, high-performance hydraulic system sealing devices and the like, and is used for meeting the sealing requirements of dynamic pressure and alternating load working conditions in the high-pressure hydraulic systems, effectively solving the problem of interface separation and effectively prolonging the fatigue life at the same time.

The invention discloses an engine test bed intercooler temperature control system comprising an intercooler used for simulating work under actual working conditions; the constant-temperature heater is used for heating the cooling liquid to a preset temperature; the electronic water pump is used for driving cooling liquid to circulate and controllable in flow; the plate heat exchanger is used for heat exchange between the external circulation chilled water and the internal circulation cooling liquid; the expansion kettle is connected into the circulating system through a three-way valve to realize water replenishing and pressure balance; the bypass valve is arranged on the water pump bypass pipeline and used for adjusting the internal circulation flow and pressure, and the PID proportional valve is arranged on the external circulation chilled water pipeline and used for dynamically adjusting the external circulation chilled water flow; and the flow meter and the temperature and pressure sensor are used for monitoring the flow and pressure of the cooling liquid and the temperature of the outlet gas of the intercooler in real time.

The utility model relates to the technical field of agricultural implements, in particular to an automatic speed regulation type traction type hydraulic self-power driving rake which comprises a frame used for being connected with a tractor, a rake body connected to the periphery of the frame, a main power device installed on the frame, a hydraulic transfer case connected to the main power device and an oil pump installed on the hydraulic transfer case. An oil pipe is connected to the oil pump, a proportional valve used for adjusting the flow of liquid in the oil pipe is installed on the oil pipe, and a branch power device used for being connected with the oil pipe is installed on the rake body. Power is transmitted through hydraulic pressure, flexible driving is carried out, a machine tool can be well protected if hard sundries exist, an oil pipe can be made of a soft pipe so that assembly layout can be more convenient and reasonable, the size of the driving harrow can be conveniently increased according to requirements, and the rotating speed of harrow teeth can be adjusted more flexibly through hydraulic transmission; the increase and decrease of the liquid flow can be steplessly adjusted through the proportional valve, so that the adjustable range of the rotating speed is expanded to adapt to different soil environment requirements.

Vehicle coolant system comprising at least two independently operable coolant circuits (3, 6, 7, 160), wherein at least a first coolant circuit (6, 7, 160) operates at a first temperature level and at least a second coolant circuit (3) operates at a second temperature level lower than the first temperature level, and wherein the first coolant circuit (6, 7, 160) is intended for temperature control of an internal combustion engine (8) or an electric machine (5) and the second coolant circuit (3) is intended for temperature control of an energy storage device (2), and wherein at least one recuperation device (37) is provided for thermally coupling the at least one first (6,7,160) and the at least one second coolant circuit (3), characterized by the fact that in the second coolant circuit (3) the recuperation device (37) is arranged in parallel to a heating device (32) by providing at least one proportional valve (34).

The invention belongs to the technical field of semiconductor wafer process treatment, and particularly relates to a wafer bonding safety floating force application device and a use method thereof. A power source is fixed to a frame, a lead screw is connected with the output end of the power source, the lead screw is in threaded connection with a nut, the nut is fixedly connected with a sliding table plate, and an air cylinder is installed on the bottom face of the sliding table plate; the pressing disc body is connected with a cylinder rod of the air cylinder, and the supporting disc body is fixed to the bottom of the frame and located below the pressing disc body. A pipeline connector of the air cylinder is connected with the electric proportional valve, the electric proportional valve outputs fixed gas pressure needed by bonding to the air cylinder, and the pressing disc body is in pressing fit with the supporting disc body when the air cylinder is in a floating force application state. By adopting a mode of combining a rapid positioning structure and a floating force application structure, floating press fit of the bonding disc in the vacuum cavity is realized, the press fit adaptivity is improved, the control difficulty is reduced, the press fit force control precision is improved, the production safety is enhanced, and the production yield of the bonding process is further improved.

The invention discloses a safety protection type power supply equipment load step-by-step detection device, which belongs to the technical field of power supply equipment detection and comprises a base plate, a movable frame is arranged at the top of the base plate, the bottom of the movable frame is fixedly mounted at the top of an electric track sliding table, and a three-stage hydraulic cylinder is fixedly mounted at the top of the movable frame. An oil inlet pipeline of the third-stage hydraulic cylinder is connected with an electromagnetic proportional valve in series, and the output end of the third-stage hydraulic cylinder is hinged to a connecting plate through a connecting block and a shaft pin. The movable frame is driven to a proper position through the electric track, then the output force is regulated and controlled by the three-stage hydraulic cylinder through the electromagnetic proportional valve, the connecting plate and the belleville spring set are pushed to enable the load pressing plate to move downwards to apply load to power supply equipment, all sensors conduct real-time monitoring in the process, and the lifting plate acts along with the load pressing plate to form protection. The load can be accurately applied step by step, the equipment state can be synchronously monitored, the good buffering and protection capacity is achieved, and the detection safety and accuracy are improved.

The invention discloses a head pasting device and method capable of adjusting pressure through pneumatic control, and belongs to the technical field of head pasting, an upper rotating shaft and a lower rotating shaft are mounted on a rotating shaft mounting seat through rotating bearings, a power device used for driving the upper rotating shaft to rotate is arranged on the rotating shaft mounting seat, and the lower rotating shaft is connected with the upper rotating shaft through a bolt; a closed cavity is formed in the connecting position of the upper rotating shaft and the lower rotating shaft, an air bag diaphragm and a piston are arranged in the closed cavity, a hollow guide shaft is coaxially arranged on the piston, the hollow guide shaft is installed in the lower rotating shaft through a guide shaft sleeve and connected with the suction nozzle assembly, and the pneumatic control pressure assembly is communicated with the closed cavity and the hollow guide shaft. According to the scheme, an air control pressure assembly is adopted, air pressure input is dynamically adjusted through an electric proportional valve, flexible transmission of an air bag diaphragm and a piston is combined, air pressure is accurately converted into linear displacement, and suction nozzle contact pressure is driven to follow a set value in real time.

The invention relates to the technical field of wall-hanging stoves, and discloses an ignition control method and device of a wall-hanging stove, a controller and the wall-hanging stove.The ignition control method comprises the steps that when ignition of the wall-hanging stove fails, the valve opening current of a gas proportional valve of the wall-hanging stove is detected, and when the valve opening current is smaller than a preset current threshold value, the valve opening current is increased, and the wall-hanging stove is controlled to execute ignition operation again; when the valve opening current is larger than or equal to the preset current threshold value, the fan rotating speed of the wall-hanging stove is detected; and when the rotating speed of the fan is larger than the preset rotating speed threshold value, the rotating speed of the fan is adjusted to the preset rotating speed threshold value, and the wall-hanging stove is controlled to execute re-ignition operation. According to the method, the valve opening current is firstly adjusted when the execution of the ignition operation fails, so that the ignition success rate of the wall-hanging stove is increased by increasing the air inlet pressure, and the rotating speed of the fan is adjusted when the valve opening current is greater than the preset current threshold value, so that the ignition failure caused by flame separation and fire transfer failure is avoided by reducing the air inlet amount of cold air; the ignition success rate of the wall-hanging stove is improved.

The invention relates to the technical field of electric vehicle thermal management, and discloses an electric vehicle thermal management system and a control method thereof. The system comprises a compressor, multiple sets of refrigerant loops and cooling liquid loops, a three-way proportional valve, an electronic expansion valve and a controller, the refrigerant loops achieve heat transfer through the compressor and a water-cooled condenser, and the cooling liquid loops distribute heat to a passenger compartment and a battery through an electronic water pump and the three-way proportional valve; according to the control method, a first, second or third initialization mode is selected based on the outside environment temperature, and multi-loop cooperative control is achieved by adjusting the opening degree of the valve, the duty ratio of the water pump and the rotating speed of the compressor. The R290 refrigerant is adopted to broaden the operating temperature range, electric drive waste heat recovery and passenger compartment waste heat utilization are combined, the low-temperature heating energy efficiency ratio is remarkably increased, the problems that an existing heat pump system is difficult to start at the extremely low temperature, heating is delayed, and energy consumption is too high are solved, and rapid temperature rising and accurate temperature control of the passenger compartment and a battery in the environment of-30 DEG C or above are achieved.

The invention relates to the technical field of hydraulic pressure, in particular to a plunger pump flow output unit, a plunger pump system and a plunger pump flow regulation and control method. The plunger pump flow output unit comprises a first cavity and a second cavity, the first cavity and the second cavity are connected between the low-pressure loop and the high-pressure loop respectively, a connecting channel is communicated between the first cavity and the second cavity, and a digital proportional valve used for adjusting the flow channel sectional area of the connecting channel is arranged on the connecting channel. The reciprocating motion mechanism comprises a driver and a plunger connecting rod, a first plunger and a second plunger are arranged at the two ends of the plunger connecting rod respectively, and the first plunger and the second plunger are arranged in the first cavity and the second cavity respectively in a sliding fit mode. According to the scheme, the defects that in the prior art, a direct-drive digital plunger pump is limited in variable range, and zero-flow output cannot be achieved are overcome, and the requirement for accurate liquid using of a fully-mechanized coal mining face hydraulic support according to needs is met.

The utility model relates to a closed hydraulic system, a walking system and a rotary system, which comprise a hydraulic pump component connected with a power source, an oil outlet of the hydraulic pump component is connected with an oil inlet of a hydraulic motor component through a first loop, and an oil outlet of the hydraulic motor component is connected with an oil inlet of the hydraulic pump component through a second loop; a third loop is arranged between the first loop and the second loop, and a proportional valve is arranged on the third loop. The proportional valve is additionally arranged to be communicated with the oil way between the hydraulic pump assembly and the rotary motor, the galloping phenomenon of closed system braking can be rapidly solved, the refitting cost is low, control and debugging are easy, and the matched debugging time is shortened.

The control system comprises a control unit, an oil tank, an oil pump, a heat exchanger, a two-position three-way slide valve, a two-position three-way proportional pressure control slide valve, a switch electromagnetic valve, a proportional electromagnetic valve, a proportional valve and an air source, the air source is respectively connected with the switch electromagnetic valve and the proportional electromagnetic valve, an air outlet of the switch electromagnetic valve is respectively connected with the two-position three-way slide valve and the two-position three-way proportional pressure control slide valve, and an air outlet of the proportional electromagnetic valve is connected with the proportional valve. During working, under the control of the two-position three-way slide valve and the two-position three-way proportional pressure control slide valve, engine oil can quickly enter the brake cavity to quickly generate brake torque, and the proportional electromagnetic valve can control the opening degree of the proportional valve to adjust the flow of the brake engine oil in the brake cavity so as to adjust the brake force. Therefore, the speed changing box has the advantages that the effect taking time of the brake oil cavity is prolonged, engine oil emulsification is prevented, the liquid filling rate is accurately controlled, oil pumping and oil leakage of the speed changing box are prevented, and air loss is reduced.

A mine dump truck wet disc brake hydraulic system, including main control valve, one end of main control valve is connected pressure oil source, the other end is connected front brake system and middle and rear brake system, front brake system includes brake pedal, front axle proportional control valve group, front axle brake valve group and front brake cylinder, middle and rear brake system includes brake pedal, slow running valve, middle and rear axle brake valve, rear axle proportional valve group, relay valve group, rear axle brake cylinder and middle axle brake cylinder, the utility model discloses a mine dump truck wet disc brake hydraulic system can realize manual operation brake and line control remote brake function, reaches unmanned operation's requirement, is used for unmanned vehicle or auxiliary driving, and in order to adapt to the distance of middle and rear axle of three axle vehicle and the distance of main brake valve group is longer, two relay valve groups are added, brake corresponding speed is improved, faster brake response is realized, makes travel more safe.