2612 results about "Relief valve" patented technology

A pump system includes a housing defining a first internal volume and a second internal volume, a first piston positioned to separate the first internal volume into a first chamber and a second chamber, a second piston positioned to separate the second internal volume into a third chamber and a fourth chamber, a first inlet check valve configured to permit fluid flow into the first chamber, a second inlet check valve configured to permit fluid flow into the third chamber, a directional control valve (DCV) repositionable between (a) a first position where the DCV is configured to fluidly couple the second chamber to a high pressure fluid source and (b) a second position where the DCV is configured to fluidly couple the fourth chamber to the high pressure fluid source, and a relief valve configured to supply a fluid to the DCV through an orifice to move the DCV.

The invention relates to the technical field of transformers, in particular to an oil-immersed power transformer which comprises a hollow rod, a first round rod, a first piston, a first spring, a cylinder, a second round rod, a second piston, a limiting block and a ventilation assembly. A hollow rod is fixedly connected to the diaphragm; a first round rod is slidably connected to the hollow rod. A first piston is fixedly connected to the first round rod and makes contact with the lower end of the hollow rod. A cylinder is fixedly connected to the box body; through cooperation of the hollow rod, the first round rod, the first piston, the first spring, the cylinder, the second round rod, the second piston, the second spring and the limiting block, pressure relief operation can be automatically completed when pressure in the transformer body is increased abnormally, and therefore the transformer body can be protected; and the transformer oil sprayed out at a high speed can be intercepted and prevented from being sprayed to the outside to pollute the environment, the intercepted transformer oil is gathered on the upper side of the diaphragm, manual collection of the transformer oil can be facilitated, and waste is avoided.

The invention provides a liquid cooling CDU system with an intelligent pressure balance tank, and relates to the technical field of electronic equipment heat dissipation, and the system comprises a main circulation loop, the intelligent pressure balance tank, a liquid supplementing loop, a control system and a monitoring module. The intelligent pressure balance tank is provided with a liquid level sensor set, an exhaust valve installed on the non-top portion and a mechanical pressure release valve. The installation height of the exhaust valve is preset so that a buffer air layer can be reserved. The control system responds to signals of the liquid level sensor and controls opening and closing of the liquid supplementing loop and the exhaust valve. Through the design of a buffer air layer and a non-top valve group of the intelligent pressure balance tank, automatic liquid supplementing and graded pressure protection logic are combined, the problems of manual liquid supplementing lag, large pressure fluctuation, high safety risk and the like of a traditional liquid cooling CDU system are solved, and the liquid cooling CDU system is suitable for efficient heat dissipation of a data center and high-power electronic equipment.

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.

The invention relates to the technical field of pressure release valves, in particular to a fire-fighting pipeline linear adjusting pressure release valve and a method, the fire-fighting pipeline linear adjusting pressure release valve comprises a first valve body, and further comprises a third valve body, a second valve body, a third valve core assembly, a second valve core assembly and a third valve core assembly, the second valve body is fixedly connected to the top of the third valve body, and a second valve element assembly is connected to the interior of the second valve body; and the pressure regulating mechanism comprises a pressure assembly communicating with the water outlet end of the first valve body, and the top of the second valve body is connected with an elastic assembly. By arranging the pressure adjusting mechanism, a traditional single spring adjusting mode is broken through, the water pressure in the sealing cover and the mechanical pressure of the adjusting screw rod and the first spring are superposed to form a composite pressure relief threshold value, and a method for linearly and finely adjusting the pressure relief threshold value is added; incompressibility of a water medium is utilized, instantaneous pressure fluctuation is absorbed, fatigue failure of the spring under high-frequency impact is effectively avoided, and the device is suitable for starting and stopping of a fire pump or scenes where water hammers frequently occur.

The embodiment of the invention provides a pressure release valve for a train, and relates to the technical field of pressure release valves. A pressure relief valve for a train comprises an outer shell, an inner shell, a first pressure relief valve plate, a second pressure relief valve plate and a third pressure relief valve plate, the first pressure relief valve plate, the second pressure relief valve plate and the third pressure relief valve plate are sequentially mounted on the inner side of the inner shell from top to bottom, a first pressure relief spring is mounted between the first pressure relief valve plate and the second pressure relief valve plate, and a second pressure relief spring is mounted between the second pressure relief valve plate and the third pressure relief valve plate. The side end of the top of the outer shell fixedly communicates with a guide pipe, a vent hole is formed in the side end of the bottom of the inner shell, an adjusting mechanism for adjusting the pressure of the first pressure relief spring and the pressure of the second pressure relief spring is installed on the outer shell, and the two-way synchronous adjusting mechanism is arranged so that the pressure relief valve can adjust different pressures needed by different latitudes conveniently. The pressure cover is prevented from being replaced in a high-latitude area, meanwhile, the adjusting pressure of a single pressure relief spring can be relieved, fatigue damage of the pressure relief spring is reduced, aging of the pressure relief spring is slowed down, and therefore the overall service life of the pressure relief valve is prolonged.

To provide a hydraulic vibration isolator having a poppet valve, which comprises a safety function for preventing damage due to overload, and can be easily replaced with an existing product without increasing the size of the existing product.SOLUTION: A poppet valve device 9 comprises a valve case 11, a valve body 13 that opens and closes a valve seat 11a opening into the valve case 11, and a spring 14 that biases the valve body 13 in an opening direction. The valve case 11 comprises: a flange part 11b that is housed in an outer case 10 communicating with an oil passage 8, slidably penetrates a relief valve seat 10a that opens into the outer case 10 to branch off and merge with the oil passage 8, and abuts against the opening peripheral edge of the relief valve seat 10a; and a relief oil passage 11c formed between a side part and an inner wall of the outer case 10 by cutting out a side part. The valve case 11 is biased by a spring 12 in a direction of closing the relief valve seat 10a. In the poppet valve device 9, excessive oil pressure causes the flange part 11b of the valve case 11 to separate from a valve seat 10a of the outer case 10, and the oil pressure is released through the relief oil passage 11c.SELECTED DRAWING: Figure 5

The utility model discloses a one-way valve with a pressure relief protection function, and particularly relates to the technical field of one-way valves, which comprises a valve body, a discharge pipe is arranged at one end of the valve body in a penetrating manner, an outer valve sleeve is arranged on one side of the valve body in a penetrating manner, a pressure relief mechanism is arranged in the outer valve sleeve, and the pressure relief mechanism comprises a pressure relief valve seat arranged in the outer valve sleeve. A guide groove is formed in the outer valve sleeve, a guide ring is slidably arranged in the guide groove, a pressure relief valve element is fixedly arranged in the guide ring, a pressure relief spring is fixedly arranged at the top of the pressure relief valve element, an adjusting disc is slidably arranged on the inner wall of the valve body, and a threaded rod is rotatably arranged on one side of the adjusting disc. When the fluid pressure abnormally rises, the pressure relief channel can be automatically opened, the one-way valve and a conveying system are effectively protected, the position of the pressure relief valve element can be conveniently and manually adjusted, pressure relief parameters are flexibly controlled, and the requirements of different working conditions are met.

The invention provides a compressor pressure relief structure, a compressor and an air conditioner. The compressor pressure relief structure comprises a first-stage compression assembly and a second-stage compression assembly. A first pressure relief channel is formed in the partition plate assembly, an assembly avoiding groove and a second pressure relief channel are formed in the second-stage air cylinder, at least part of structure of an opening and closing element is arranged in the assembly avoiding groove, and the opening and closing element can move in the assembly avoiding groove and the second pressure relief channel so that the second pressure relief channel can be communicated with or disconnected from the first pressure relief channel; the opening and closing element comprises a first end and a second end which are opposite to each other, the first end is opposite to the first pressure relief channel so as to bear the gas pressure of the first pressure relief channel, the second-stage air cylinder is further provided with a first back pressure channel, and the first back pressure channel can introduce exhaust gas of the compressor into the assembly avoiding groove; and the pressure acts on the second end so as to apply pressure to the second end. According to the compressor, the technical problem that in the prior art, a rivet pressure relief valve plate structure is adopted for a compressor, and flutter occurs can be solved.

The utility model provides a battery box body, a battery and a power utilization device. And a heat dissipation system is arranged in the battery box body. The heat dissipation system comprises a pressure relief device and a fire extinguishing device. The pressure relief device comprises an exhaust channel and a pressure relief valve, an air inlet of the exhaust channel is formed in the battery box body, and an air outlet of the exhaust channel is communicated with the pressure relief valve. The exhaust channel is used for conveying high-temperature gas to the pressure release valve. And the pressure release valve is used for discharging high-temperature gas in the battery box body. The fire extinguishing device is provided with a containing cavity, and a fire extinguishing medium is stored in the containing cavity. The containing cavity communicates with the exhaust channel, so that the fire extinguishing medium can enter the exhaust channel. According to the pressure relief device, the battery with thermal runaway can be timely cooled and exhausted, so that the safety of the power utilization device is ensured. And a fire extinguishing medium in the fire extinguishing device enters the exhaust channel and extinguishes flames in the exhaust channel, so that the flames are prevented from being exhausted out of the battery box body to cause heat diffusion, the risk of battery damage is reduced, and the safety of the electric device is further ensured.

The invention discloses a supercritical fluid assisted polymer devolatilization distributor. The supercritical fluid assisted polymer devolatilization distributor comprises a gradually-shrinking channel, a throttling channel and a gradually-expanding channel which are connected in sequence. A static mixer is arranged in the throttling channel, the upstream pressure is maintained to be above a supercritical state by increasing fluid resistance, meanwhile, the mixing effect of supercritical fluid and polymer melt is enhanced, stable and uniform foam flow is formed, and pressure fluctuation is avoided; an automatic pressure relief valve assembly is arranged on the upper portion of the divergent channel and composed of a valve opening, a valve cover plate, a spring, an adjusting knob and the like, when the system pressure exceeds a set value, exhaust is automatically started, and controllable pressure relief is achieved. A plurality of rows of flow distribution holes are formed in the lower part of the distributor to ensure that the melt uniformly flows out to form stable melt strips; the problems that traditional equipment is difficult to pressurize and not timely in pressure relief are solved, the supercritical state maintenance, gas-liquid separation and melt forming processes are optimized, the volatile component removal efficiency is improved, the phenomenon that melt strips are broken or accumulated is effectively prevented, and continuous and stable operation of the devolatilization process is guaranteed.

The invention relates to the technical field of water treatment, in particular to a prawn fry raw water biological filter treatment device. According to the technical scheme, the device comprises a pretreatment box, a disinfection box, an adjusting plate, a fine treatment box, a motor and a purification box, a screw is arranged at the output end of the motor, a nut in threaded installation with the screw is arranged at the upper end of the adjusting plate, the outer wall of the adjusting plate is sleeved with an air bag, an air pump is arranged at the upper end of the adjusting plate, and the air pump and the air bag are communicated and provided with an air supply pipe; a pressure relief valve is arranged in the air supply pipe, a disinfection box is arranged on one side of the lower portion of the fine treatment box, sealing gaskets are arranged on the inner wall of the fine treatment box and the outer wall of the purification box, overflow holes are formed in the side wall of the lower end of the purification box, and a filter material layer is arranged in the purification box. Through modular design, the efficiency and economical efficiency of prawn fry raw water treatment are remarkably improved, and the problems that a large-area biological filter cannot flexibly adjust the treatment capacity and is difficult to adapt to different scale requirements are solved.

The invention discloses an air source heat pump unattended control method and system, and relates to the field of equipment control, and the method comprises the steps: predicting a load demand according to an environment parameter and a building load parameter, and calculating a target water supply temperature based on the load demand; sorting the heat pump units according to the equipment operation duration parameters, distributing a temperature deviation value for each heat pump unit, and calculating the target water supply temperature and the temperature deviation value corresponding to the heat pump unit to obtain the personalized set temperature of each heat pump unit; a starting instruction sequence is generated according to a preset starting condition and the personalized set temperature, and after the water return pressure parameter reaches a preset parameter threshold value after the circulating water pump is started, all the heat pump units are sequentially started according to the personalized set temperature sequence; and a make-up pump and a pressure release valve are controlled according to the return water pressure parameter and the liquid level parameter, and the temperature deviation value of each heat pump unit is adjusted according to the change of the environment parameter and the building load parameter. By implementing the method, the balance of equipment loads in the multi-unit system can be improved.

The invention relates to a monitoring, prevention and control system for filling and pipe plugging, which comprises a ground integrated console, a distributed optical fiber acoustic monitoring system, a pressure detection mechanism and a discharge mechanism, and is characterized in that the ground integrated console is electrically connected with the distributed optical fiber acoustic monitoring system, the pressure detection mechanism and the discharge mechanism through a communication system, and data connection is established; at least one distributed optical fiber acoustic monitoring system and at least one pressure detection mechanism are connected with the pipe wall of the filling pipeline and distributed in the axis direction of the filling pipeline, and the discharging mechanism is connected with the filling pipeline. The use method comprises the following four steps: optical fiber laying, system operation flow, pipe blockage judgment and active prevention and control, and mechanism maintenance. Precise positioning of the pipe blocking position can be achieved, the pipe blocking area is determined in combination with the acoustic signal spatio-temporal evolution law, active regulation and control of filling and pipe blocking are achieved through the pressure release valve and the vibration ring, the problem of response lag caused by traditional manual troubleshooting or single-parameter triggering is solved, and the timeliness of field emergency disposal is improved.

The present application relates to pipeline system damping and noise reduction technical field, provide a kind of active noise cancellation pressure relief valve, comprising: valve body, with the liquid inlet cavity and pressure relief cavity being communicated are formed;Bypass pipe, with liquid inlet cavity is communicated;Piezoelectric actuator and pressure relief component, pressure relief component includes adjusting piece, pressure relief elastic piece and pressure relief valve core, pressure relief valve core and pressure relief elastic piece are set in pressure relief cavity, adjusting piece is movably arranged on valve body, piezoelectric actuator is arranged on adjusting piece, pressure relief elastic piece is pressed between piezoelectric actuator and pressure relief valve core;Piezoelectric actuator is configured to drive pressure relief elastic piece, to eliminate the transient noise caused by pulsating pressure when pressure relief valve core moves.The active noise cancellation pressure relief valve provided by the present application introduces active noise cancellation technology into the active noise cancellation pressure relief valve pulsating noise control by arranging piezoelectric actuator, can be adjusted by pressure relief elastic piece The force exerted on the pressure relief valve core can eliminate the transient noise caused by pulsating pressure when the pressure relief valve core moves.

A pressure-relief valve includes a main body equipped to be fastened to a flexible package material. The main body has at least one through hole forming a passage through the main body. A valve membrane lies, on a package side, against the main body in a region around the hole, and a sealing liquid between the main body and the valve membrane. The valve has a water-soluble polymer, whereby at least one component of the valve, for example the main body, is made of a polymer composition that includes a water-soluble polymer.

Disclosed in the present invention are an apparatus and method for inhibiting thermal runaway of a battery. The apparatus comprises pressure relief valves located at the tops of batteries; a detection box is provided above the pressure relief value of each battery; the plurality of detection boxes are communicated with each other; and each detection box is filled with a liquid fire extinguishing agent and an inert gas. A fire extinguishing mechanism of the present invention has a simple structure, and does not need a corresponding electric control mechanism to maintain normal operation of a fire extinguishing apparatus, so that the present invention has low cost and is conducive to application and popularization in the field of energy storage.

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.

A hydraulic circuit includes a first oil path, a second oil path, a hydraulic control circuit, a third oil path, a check valve, and a relief valve. The first oil path links to a discharge port of a first oil pump. The second oil path links to a discharge port of a second oil pump. In the hydraulic control circuit, a first regulator valve is disposed downstream of a confluence point of the first oil path and the second oil path. The third oil path connects a suction port of the first oil pump and a strainer. The check valve is provided in the third oil path and restricts a movement of oil toward the strainer side. The relief valve is provided in the third oil path and discharges oil in the third oil path to an outside when a pressure in the third oil path exceeds a reference pressure.

PROBLEM: To avoid the pressure of the actuator oil passage from becoming higher or equal to the upper limit pressure that is set depending on an individual option hydraulic actuator, during non-operation of an option operation lever, even if the actuator oil passage connected to the option hydraulic actuator is not provided with a variable relief valve. SOLUTION: It is configured to release the pressure of the actuator oil passage into the oil tank via the option control valve, the load pressure introducing oil passage, the variable relief valve, by switching the option control valve to load pressure relief positions at which the pressure of the actuator oil passage is allowed to flow into the load pressure introducing oil passage, when the pressure of the actuator oil passages exceeds the upper limit pressure during non-operation of the option operation lever; as well as by controlling the relief setting pressure of the variable relief valve connected to the load pressure introducing oil passage so as to be less than or equal to the upper limit pressure.

The utility model discloses a powder dredging valve which comprises a valve body connected with a stock bin shell through a connecting piece, the left side of the valve body is communicated with an energy storage device, and the lower portion of the valve body is communicated with a pressure release valve. A valve cover connected with the valve port is arranged in the valve body in a sliding mode, and a thin film which drives the valve cover to move downwards and controls the valve port to be opened after pressure relief of the pressure relief valve is installed in the valve body. A gas source connector is arranged on a valve body passage communicated with the energy storage device, and a gas source conveying pipeline for conveying gas into the energy storage device is mounted at the gas source connector; an exhaust port is formed in a valve body passage opposite to the air source interface, the exhaust port is communicated with an air cylinder through a control air pipe, and the air cylinder is connected with a pressure release valve and controls the pressure release valve to be opened; a nozzle matched with the energy storage device to blow away blocked materials is formed in the connecting piece extending into the material bin shell; according to the utility model, the energy storage device communicated with the valve body is matched with the pressure release valve, so that air is introduced into the stock bin at a certain frequency, blocked materials are dredged, and the blanking efficiency is improved.

The invention discloses a battery module thermal runaway detection method and a battery module thermal runaway detection system. The detection method comprises the following steps: acquiring a sound signal of a battery module; based on the sound signals, a first type of sound events related to opening of a battery pressure release valve and a second type of sound events related to electric arcs generated in a battery module are recognized, and the occurrence time and the occurrence position of the first type of sound events and the occurrence position of the second type of sound events are recorded; and based on the specific relationship between the occurrence time and the occurrence position of the first type of sound event and the second type of sound event, judging whether the first type of sound event and the second type of sound event are coupled at the same or adjacent position in a preset time window so as to determine the thermal runaway risk level of the battery module. By jointly judging the two key events of pressure release valve opening and arc generation, the thermal runaway state of the battery module with high combustion or explosion risk can be identified more accurately and more timely, and effective detection of the thermal runaway of the battery module is realized.

The invention relates to the technical field of battery explosion prevention, in particular to an automobile storage battery with an explosion-proof function. A cavity is formed between the battery body and the top cover; a plurality of connecting blocks I are fixedly connected to the battery body; the connecting block I has a heat conduction function; the battery body is in sliding connection with a piston plate; a plurality of second connecting blocks are fixedly connected to the piston plate; according to the storage battery, electrolyte steam is condensed and refluxed through the first connecting blocks which are densely distributed, so that the electrolyte steam cannot flow to the pressure release valve when the storage battery normally operates, the problem of blockage of the pressure release valve is avoided, the pressure release valve can normally release pressure and is high in safety, and in the pressure release process, the first connecting blocks which are originally used for condensation and are densely arranged are not prone to falling off. And a plurality of damping friction areas can also be formed between the first connecting block and the second connecting block, so that relatively large friction resistance is generated to reduce the impact energy of water vapor, the range of the electrolyte sprayed out of the pressure release valve is reduced, and the ignition risk is reduced.

Methods and systems for generating hydrogen gas from a source of pressurized water, for example, from an existing water main of a water distribution system, are provided. The methods and systems employ turbine / generators and water electrolyzers electrically powered by the turbine / generators. The turbine / generators are powered by the energy available in existing water distribution systems, for example, municipal, industrial, or agricultural systems, to access energy that typically is discarded, for example, via a pressure relief valve. The hydrogen gas generated may be used to fuel hydrogen powered vehicles, for example, cars, trucks, and forklifts, or as a fuel for power generation. Excess electrical energy produced by the generator may be distributed to the local power grid. Aspects of the invention may also be used to generate oxygen gas from the electrolysis of water, and then generate ozone gas from the oxygen gas for treating water, among other uses.

The application provides a hydraulic control valve test system and method, comprising a hydraulic pump station system for providing hydraulic power during a test process; the hydraulic pump station system comprises an oil tank system, the oil tank system is connected with a first main pump motor set system and a second main pump motor set system in parallel, the first main pump motor set system is used for providing hydraulic power for a first test system, and the second main pump motor set system is used for providing hydraulic power for a second test system; a control pump motor set system is connected to the oil tank system and is used for providing hydraulic power for a third test system; the first test system, the second test system and the third test system are connected with a control valve test bench system used for testing a valve to be tested; the valve to be tested comprises a flow valve, a balance valve, a pressure reducing valve and a relief valve.

The utility model discloses a power battery pack anti-collision box body device with thermal runaway protection. The power battery pack anti-collision box body device comprises a box body for placing a power battery module (8), a front-back buffer structure (1), a passive anti-collision plate, a thermal runaway control device (3), a displacement damping plate (4), a partition plate (5), a cover plate (9), a built-in liquid cooling plate (6) and a phase change material plate (7). According to the device, the design of a front-back buffer structure, a passive anti-collision plate and a displacement damping plate is adopted, so that side edge protection and bottom edge protection measures are provided for the power battery module; according to the utility model, the design of the thermal runaway control device is adopted, so that thermal runaway control is provided for the power battery module; when the vehicle is in use, a refrigerant and a deoxidant in the execution module are triggered to operate together, batteries in the subareas are rapidly refrigerated and rapidly extinguished, a one-way pressure release valve is opened to discharge high-temperature and high-pressure gas, and a vehicle alarm device is started to remind people in the vehicle and around the vehicle to get away immediately, so that the life and property safety of people is protected, and an important role is played.

An in-tank fuel pump assembly and mounting system is disclosed which may be configured for mounting inside a fuel tank. The assembly includes a pump housing, pump mounted to the housing, and pressure relief valve. The housing may comprise upper and lower pump housing units coupled together. The upper housing unit is configured for mounting to a tank opening, which in one implementation may be the fuel fill opening. The lower housing unit extends into the tank to approximately the bottom of the tank. A fuel fill fluid pathway is created through the housing for adding fuel to the tank while the pump assembly remains in situ. The upper housing unit may include a removable fuel cap. The pump housing may include an integral vapor trap.

A brake upper pump with double oil seals and lateral pressure relief comprises a brake pump body which is provided with a piston cavity and an oil storage cavity which are communicated with each other. The brake handle is in running fit with the brake pump body, and the brake handle is in transmission fit with the piston mechanism; the oil pipe assembly is communicated with the piston cavity; the piston mechanism comprises a piston body, a first oil seal and a second oil seal, the second oil seal is located on the front side of the first oil seal, and the effective oil pushing area S1 of the second oil seal is smaller than that of the first oil seal; the reset spring acts on the piston body; the pressure relief valve mechanism is mounted in the pressure relief cavity of the brake pump body; the piston cavity is at least provided with a large-diameter cavity section, a small-diameter cavity section and a variable-diameter cavity section, and the pressure relief cavity is communicated with the variable-diameter cavity section through a pressure relief channel. A large-small-diameter double-piston oil seal structure is adopted, the effect that the front section has a relatively large oil seal area and the rear section has a relatively small oil seal area is achieved, and the overall brake performance can be more linear.

The utility model discloses a pressure release valve capable of controlling flow, which relates to the technical field of pressure release valves and comprises a medium inlet and a valve seat, the valve seat is mounted above the medium inlet, a medium outlet is mounted on the right side of the valve seat, a limit block is arranged above the valve seat, and a movable block is mounted below the limit block through a valve rod. The pressure release valve capable of controlling the flow is provided with a flow adjusting frame, when the flow of a medium outlet needs to be adjusted, an electric telescopic rod can be started, the electric telescopic rod can drive a sliding rod to move up and down, and the sliding rod drives a first fixing block and a first rotating shaft assembly to move up and down; and then the first rotating shaft assembly drives a connecting strip to push a second fixing block and a flow adjusting frame, so that the flow adjusting frame can be driven to move left and right, the contact area of a filter screen and a medium in the flow adjusting frame can be adjusted, the flow of the medium can be adjusted, the flow adjusting frame moves leftwards, the flow is increased, and the flow adjusting frame moves rightwards, and the flow is reduced.

The invention discloses a low-temperature upper-stage power system, and relates to the field of spaceflight. Comprising a gas cylinder, a pressure supplementing electromagnetic valve, a pressure supplementing pore plate, a self-generation pressurizing electromagnetic valve, a self-generation pressurizing pore plate, a storage tank, an overflow valve, a storage tank pressure sensor, a pressure stabilizing valve, a circulating pump, a circulating control valve, a pump front valve, a Joule-Thomson throttling expansion valve, a heat exchanger and a branch supply control valve; the main engine subsystem comprises a pump, a turbine, an auxiliary valve, a fuel gas generator, a main valve, a precooling backflow valve, a main thrust chamber, an evaporator, a starting gas cylinder, a starting gas cylinder control valve, a main thrust chamber igniter and a fuel gas generator igniter. The attitude control engine subsystem comprises a plurality of attitude control engines; each attitude control engine comprises an attitude control thrust chamber, and an oxidant control valve, a fuel control valve and an attitude control thrust chamber igniter are arranged on each attitude control thrust chamber. Propellant supply of the main engine and the attitude control engine is achieved through the unified pressurization conveying system.