41results about How to "Stable pressure value" patented technology

The invention discloses a method for calculating fractional flow reserve based on a pressure sensor and a contrast image. The method comprises the following steps: acquiring pressure of a heart coronary mouth in real time through a blood pressure sensor; storing a pressure numerical value to a data link list; storing the data link list by using time as an index in a form of time and real-time pressure key value pairs; acquiring the contrast time according to contrast images and searching corresponding data from a data queue according to the time index by using the contrast time as an index value, and screening out stable pressure waveform in multiple periods so as to acquire average pressure Pa; acquiring the length of a section of blood vessel from the contrast images of two body positions so as to acquire blood flow velocity; calculating pressure drop delta P at the section of the blood vessel at the inlet blood flow velocity V; calculating far-end pressure Pd of the blood vessel tofurther calculate the contrast fractional flow reserve. According to the method disclosed by the invention, the stable pressure value after injection of contrast agent can be accurately acquired; theaverage blood flow velocity of one cardiac cycle can be accurately acquired through the pressure waveform and the contrast images, so that the accuracy of FFR (Fractional Flow Reserve) can be greatlyimproved.

The invention relates to an automobile fitting, in particular to an automobile seat adjusting controller capable for controlling safely, can well solve the problem that discomfort and potential hazards are brought to people or objects on a copilot seat in the prior art, and adopts the technical scheme that the automobile seat adjusting controller adopts a voltage-stabilized source for power supply, and comprises a control chip, a regulating switch, a motor driving module and a seat regulating motor, wherein the control chip is electrically connected with the seat regulating motor through the motor driving module; the regulating switch is electrically connected with the control chip; the automobile seat adjusting controller further comprises a gravity sensor; and the gravity sensor is electrically connected with the control chip. The automobile seat adjusting controller can control an automobile seat safely, and prevent excess adjustment of the copilot seat, so as to ensure that a passenger on the copilot seat cannot feel discomfortable.

A check valve for a pump of an electronically controlled brake system includes a valve body provided with a fluid path, a spring seat placed in an outlet of the fluid path of the valve body, a valve rod fitted at a lower end thereof into an inlet of the fluid path of the valve body, a valve piston provided with a through hole that is selectively opened and closed by an upper end of the valve rod, as the valve piston moves upward and downward along an inner wall of the valve body, and a spring interposed between the spring seat and the valve piston.

The invention relates to a water-saving performance test device of a building water supply system water using apparatus, which belongs to the field of water supply and drainage and relates to an experimental teaching device for testing the water-saving performance of the building water supply system water using apparatus. The device comprises a pressure supply and control system, a water supply pipe network and water using apparatus test system and a data acquisition and processing system, wherein the pressure supply and control system comprises a variable-frequency water pump (2) and a frequency-modulated water pump control cabinet, supplies high pressure and low pressure needed by a pipe network and accurately controls pressure points needed by an experiment through continuously converting frequencies and regulating a manual valve (3), wherein the variable-frequency water pump (2) comprises a high-pressure variable-frequency pump and a low-pressure variable-frequency pump which concurrently work, and the frequency-modulated water pump control cabinet is used for controlling the variable-frequency water pump (2). The variation tendency and the process of data can be observed through various curves instantly drawn by water supply system testing software, and the actual operation working condition of each node water using apparatus is reflected on a picture to be more visually known and grasped by students. The device has the characteristics of less occupied land, economical property, practicability, environmental protection, no pollution, safety, reliability and stable operation.

The invention discloses a hydraulic system of a coil stripping car and belongs to the technical field of steel-making equipment. The system comprises a lifting oil cylinder arranged at the bottom of the coil stripping car, wherein a first hydraulic control reversal valve is arranged between the lifting oil cylinder and a pressure oil source; a balance valve is arranged between a rodless cavity of the lifting oil cylinder and the first hydraulic control reversal valve; a control end of the balance valve is connected with a rod cavity of the lifting oil cylinder; a third hydraulic control lock and a second overflow valve are sequentially connected between the rodless cavity of the lifting oil cylinder and an oil return end of the pressure oil source; a control end of the third hydraulic control lock is connected with a solenoid control valve; and a pressure sensor is connected between the rodless cavity of the lifting oil cylinder and the third hydraulic control lock. The hydraulic system can solve the problems of low feedback sensitivity of the pressure sensor to the pressure change of the lifting oil cylinder, and crush damage and interlayer adhesion damage of an inner race and an outer race of a coil due to pressure fluctuation of the hydraulic system in the existing hydraulic system of the coil stripping car.

The invention provides an experiment device and a method of a rainfall side slope model under lateral non-uniform loading conditions. The experiment device comprises a model box, a lateral non-uniform loading system and a rainfall system, wherein the lateral non-uniform loading system is arranged on the left side of the model box; the rainfall system is arranged at the top of the model box; the lower end of a pressing plate in the lateral non-uniform loading system is hinged to the bottom of the model box; the left side of the upper end of the pressing plate is hinged to an oil cylinder piston which is mounted on an oil cylinder support base; under the action that a piston is pushed by hydraulic equipment to move, the pressing plate can be controlled to rotate around a connecting rod support base at the lower end. By adopting a lateral non-uniform loading mode, the characteristics that an upper part has large displacement and a lower part has small displacement in the deformation process of a side slope are achieved, and actual deformation characteristics of the side slope are relatively really simulated. Through simultaneous rainfall and lateral non-uniform loading simulation, the side slope deformation degree, the infiltration depth and the position of a sliding surface can be tested under different rainfall types and different lateral non-uniform loading conditions. The problems that single external influence factors are available and actual side slope deformation is not met in conventional artificial rainfall simulation tests can be effectively solved.

The invention discloses a well killing operation throttle valve automatic control system based on feedback adjustment and a method thereof. The well killing operation throttle valve automatic control system comprises a self-healing controller (1), a PLC (2), a central computer (3), a feedback compensator (4), a throttle valve (5), a stand pipe pressure transmitter (6), a sensor-data collection system (7), a feedforward compensator (8) and a basic data source (9). The topological structure of the automatic control system is shown as in an attached map. The well killing operation throttle valve automatic control system and the method thereof have the advantages that the well killing process can be simulated before well killing according to well killing related data through a software related algorithm according to the transmission speed and attenuation law of liquid phase pressure waves; the progress curve of whole well killing operation and the initial control curve of the throttle valve are obtained; the initial control curve of the throttle valve is fitted by the computer according to a simulation result, and the throttle valve is controlled through the PLC; in the operation process, the throttle valve is subjected to feedback adjustment through the feedforward compensator to enable the pressure of a stand pipe to be stabilized within a set range all the time; and possible faults are diagnosed and corrected by the self-healing controller. By adoption of the well killing operation throttle valve automatic control system, delays and errors caused by manual operation are avoided, remote automatic operation can be achieved, and safety hazards are avoided.

The invention provides a roller device, which comprises a roller body, a pressure sensor, a pressure stabilizing circuit and a processor. The pressure sensor is arranged on the surface of the roller body or both ends of the roller body, and is used for collecting the pressure data of the roller body. The input end of the voltage stabilizing circuit is connected with the pressure sensor, and the output end is connected with the processor, which is used for stabilizing the pressure data and sending the stabilized pressure data to the processor. The processor is used for determining and countingthe pressure value of the roller body in real time according to the pressure data after the pressure stabilization processing. The pressure stabilization circuit is used to ensure the stability of thepressure value of the roller device, and the working state of the roller can be detected in real time, which is convenient for the staff to carry out subsequent monitoring, use, or maintenance and other operations.

The invention discloses a pressure stabilizing device of a metering pump, comprising a containing cavity installed in a valve body and a pressure cover hermetically fixed outside a containing cavity; the containing cavity is provided with a liquid inlet and a liquid outlet both communicated with the fluid flow passage of the metering pump; a lower valve body tightly matched with the liquid outlet is arranged at the liquid outlet; the lower valve body is provided with a guide flow passage communicated with the liquid flow passage of the metering pump; a pressure sealing piece is installed by matching the guide flow passage; a first elastic piece is installed between the pressure sealing piece and the pressure cover; the pressure of the liquid in the containing cavity controls the opening and closing of the pressure sealing piece and the guide flow passage; the liquid in the containing cavity enables the pressure sealing piece to lose the pressure to seal the guide flow passage, that is the stable pressure of the metering pump; the top of the pressure cover is provided with an adjusting screw; and the adjusting screw can be used for changing the pressure value of forcing the pressure sealing piece to not seal the guide flow passage. The device has simple structure and high stability precision, and the pressure can be freely adjusted.

The invention provides an energy-saving fresh air system, and relates to a building internal air conditioning system which comprises a fresh air unit, a fresh air pipeline, a bypass mechanism and a tail end start-stop mechanism. The fresh air unit is provided with an air inlet end and an air outlet end. One end of the fresh air pipeline is connected to the air outlet end, the other end of the fresh air pipeline is connected to the tail end start-stop mechanism, one end of the bypass mechanism is connected to the end, close to the fresh air unit, of the fresh air pipeline, the other end of thebypass mechanism is connected to the air inlet end, and the fresh air pipeline and the air inlet end are selectively connected according to the static pressure value of the fresh air pipeline. Compared with the prior art, the energy-saving fresh air system is simple in structure, low in manufacturing cost, easy to popularize, stable, easy to maintain, and capable of greatly reducing fresh air energy consumption and saving energy.

The invention provides a filling machine liquid level negative pressure vacuum pump wine discharging device which comprises a filling machine, a pipeline, a sedimentation tank, a negative pressure vacuum pump, a one-way valve, an electromagnetic valve and a liquid level sensor, wherein the sedimentation tank is connected with the negative pressure vacuum pump and the filling machine respectively through the pipeline; the top end of the sedimentation tank is connected with the pipeline; the liquid level sensor is mounted at the lower middle part of the sedimentation tank; the electromagnetic valve and a manual valve are mounted at the bottom of the sedimentation tank. With the adoption of the filling machine liquid level negative pressure vacuum pump wine discharging device, the safety of the motor of the negative pressure vacuum pump can be ensured, the vacuum pressure value can be stabilized, the problem about bacterial contamination caused by intake and residue of wine liquor is solved, the product quality and the production efficiency can be guaranteed, and the production continuity, safety and sanitation are ensured.

The invention relates to an atmosphere purification method. The atmosphere purification method comprises the following steps of: a filtering component and pipeline gas washing step: inflating a filtering component and a pipeline connected with the filtering component through inert gas so as to exhaust air; and sucking atmosphere in a 3D printer into the filtering component through an air suction pipeline to be subjected to smoke and dust removal treatment and then sending the atmosphere back into the 3D printer through an air blowing pipeline to form a filtering and purifying loop, and removing smoke and dust in circulation. The invention further provides an atmosphere purification system; The atmosphere purification system comprises the filtering component, and the filtering component is connected with the 3D printer through the air suction pipeline and the air blowing pipeline to form a filtering and purifying circulation loop; and an air suction control valve is arranged at the connecting end of the air suction pipeline and the 3D printer, an air blowing control valve is arranged at the connecting end of the air blowing pipeline and the 3D printer, the air suction pipeline and the air blowing pipeline are connected through a connecting pipeline, the filtering component is connected with an inert gas source through an air inlet pipeline, and a connecting pipeline control valve is arranged on the connecting pipeline. Smoke dust is isolated through the filtering component to obtain cleaned gas in circulation.

The invention discloses a sealing leakage test device for an oil-immersed transformer. The device comprises an oil pump, a control unit, a pressure gauge and a remote control switch, wherein an oil tank is connected with the oil pump of the sealing leakage test device through a pipeline; the control unit is arranged on the oil pump; valves are mounted at outlets of both the oil pump and the oil tank; the pressure gauge is arranged on the pipeline; the control unit comprises two outgoing lines, one of the outgoing lines is connected with a power supply, the other outgoing line is connected with an oil pump motor, and the control unit controls the working state of the oil pump according to a standard product leakage test pressure value or the pressure of a pressure relief valve; and the remote control switch is mounted at a power supply input end. The sealing leakage test device has the advantages of simplicity and flexibility in operation, high detection rate, adjustable test pressure, automation in control, remote power interruption and wide application range and is low in investment, applicable to products of all voltage classes and beneficial to the improvement on the product quality.

The invention discloses assembling equipment for an automobile mechanical water pump, which comprises a workbench, a placing and positioning mechanism used for vertically placing a shaft connecting bearing and a water seal, a water pump body fixing seat and a pressing mechanism provided with a pressing head are sequentially arranged on the workbench from bottom to top, a through hole allowing the shaft connecting bearing and the water seal to penetrate through is formed in the water pump body fixing seat, the pressing head, the center hole of a water pump body fixedly installed on the water pump body fixing seat and the through hole are coaxially arranged from top to bottom in the vertical direction, the placing and positioning mechanism can be horizontally and movably arranged on the workbench and used for sequentially moving the shaft connecting bearing and the water seal to the position under the through hole, and the pressing mechanism is provided with a pressure sensor used for detecting the pressure value of the pressing head, a displacement sensor used for detecting the pressing stroke of the pressing head and a PLC with a preset displacement range and a preset pressure value range. The assembling equipment has the advantage that the produced automobile mechanical water pump is good in consistency.

The invention provides a pressure-regulating device and a pressure-regulating method inside a pot and the pot. The pressure-regulating device comprises a pressure sensor unit, a treatment unit, a comparing unit and an adjusting unit, wherein the pressure sensor unit is used for acquiring the air pressure value at the position of the pot and acquiring a pressure value inside the pot in real time, the treatment unit is used for calculating the difference between the preset air pressure value and the air pressure value obtained by the pressure sensor unit, so as to obtain a first difference value, and calculating the difference between the pressure value and the air pressure value acquired by the pressure sensor unit so as to obtain a second difference value, the comparing unit is used for comparing the first difference value and the second difference value to obtain a comparison result; and the adjusting unit is used for adjusting the pressure value inside the pot according to the comparison result of the comparing unit, so as to control the difference value between the pressure value inside the pot and the preset air pressure value within the preset range. With the adoption of the technical scheme, the pressure inside the pot can be automatically adjusted so that the pressure value inside the pot is maintained on a balance point.

A check valve for a pump of an electronically controlled brake system includes a valve body provided with a fluid path, a spring seat placed in an outlet of the fluid path of the valve body, a valve rod fitted at a lower end thereof into an inlet of the fluid path of the valve body, a valve piston provided with a through hole that is selectively opened and closed by an upper end of the valve rod, as the valve piston moves upward and downward along an inner wall of the valve body, and a spring interposed between the spring seat and the valve piston.

The invention discloses a pressure adjusting valve belonging to the field of machining equipment and comprising a valve body, wherein the valve body comprises a valve cavity, and an inlet and an outlet which are formed in two sides of the valve cavity and are communicated with each other, and also comprises a valve core assembly, a valve seat assembly, a handle, a damping opening and a reset spring; the valve core assembly is arranged in the valve cavity and can be used for opening and closing the valve opening of the pressure adjusting valve; the valve seat assembly is provided with a diaphragm; the diaphragm is arranged above the valve core assembly; the handle is connected with the upper end of the valve seat assembly; the valve seat assembly can move up and down in the valve cavity by the rotation of the handle; the damping opening is formed in the side of the outlet of the valve cavity; the diaphragm can move up and down in the valve cavity to adjust the size of the damping opening; one end of the reset spring is arranged at the bottom end of the valve core assembly; the other end of the reset spring is fixedly connected with the valve body at the bottom of the valve cavity; during use, output pressure at the outlet is kept, adjusted and determined by balance of force acting on the diaphragm and overflow.

The invention discloses a servo motor pressure and gap control device under a position mode. The servo motor pressure and gap control device is characterized by comprising a servo motor, a servo driving cylinder, a force sensor, an elastic piece, an upper die seat, a lower die seat, a position sensor and a control module, wherein the control module comprises a servo driver, an I / O system and a master controller, the master controller comprises a PLC, a position controller, a speed controller and a current controller, the position sensor is connected with the PLC, a position ring D is built, aposition ring C of an internal encoder of the servo motor and the built position ring D are combined to form a position control dual-closed ring so as to achieve gap control of an upper die and a lower die, the force sensor is connected with the PLC, a pressure ring E is built, and the position ring C of the internal encoder of the servo motor and the built pressure ring E are combined to form a force control dual-closed ring so as to achieve pressure control of the upper die on a test piece.

The invention provides a wireless conveying roller for assembling. The wireless conveying roller comprises a driving device, a transmission device and a wireless roller set; the wireless roller set comprises a plurality of wireless rollers which are arranged in parallel; the driving device is in transmission connection with the transmission device and is used for driving the transmission device towork; the two adjacent wireless rollers are connected through the transmission device, and the transmission device drives all the wireless rollers to roll; each wireless roller comprises an acquisition circuit, a processor and a wireless communication module; the acquisition circuits are connected to the processors and are used for sending the collected roller state data to the processors; and the processors are further connected to the wireless communication modules and are used for sending the roller state data to the outside through the wireless communication modules. According to the wireless conveying roller, a set of wireless rollers can be driven through the driving device and the transmission device, the working states of the wireless rollers can be unified while the cost of the driving device is saved, and article can be transported conveniently during assembly.

The invention relates to the technical field of physical performance detection, and relates to a tension and compression force application device, which comprises a bidirectional telescopic cylinder, a connecting assembly, a tension and compression force sensor, a first positioning piece and a second positioning piece, and is characterized in that the bidirectional telescopic cylinder comprises a shell and a moving piece, and the moving piece is suitable for switching between a tension force application position and a pressure force application position; the moving part comprises a first telescopic rod and a second telescopic rod which are oppositely arranged; the connecting assembly is suitable for being connected with a force-applied piece. The tension-compression type force sensor is connected between the second telescopic rod and the connecting assembly; the first positioning piece is connected to the first telescopic rod, and is limited at the first end of the shell at the pulling force application position so as to limit the first telescopic rod to extend out of the shell by a first length; the second positioning piece is connected to the second telescopic rod, and the second positioning piece is limited at the second end of the shell at the pressure application position so as to limit the second telescopic rod to extend out of the shell by a second length. The pulling and pressing force application device is simple in structure, low in cost and suitable for multi-point pulling and pressing force application occasions.

Disclosed is a gas injection sealing machine for compressing and locking gas springs. The gas injection sealing machine comprises a gas injection device body, a gas inlet, a hydraulic cylinder and a sealing plug cover. A notch corresponding to the rear portion of a gas spring cylinder is formed in the front portion of the gas injection device body, the rear portion of the gas spring cylinder barrel is arranged in the notch in the front portion of the gas injection device body, and the rear portion of the gas spring cylinder is hermetically connected with the notch in the front portion of the gas injection device body; an actuating rod is arranged on the front portion of the hydraulic cylinder, a notch corresponding to the actuating rod on the front portion of the hydraulic cylinder is formed in the rear portion of the gas injection device body, and the actuating rod on the front portion of the hydraulic cylinder is arranged in a notch in the rear portion of the gas injection device body, is hermetically connected with the notch in the rear portion of the gas injection device body, and abuts against the sealing plug cover; and a gas inlet is formed in the upper part of the gas injection device body, and the gas injection device body is filled with high-pressure nitrogen. According to the gas injection sealing machine for the compressing and locking gas springs, firstly, gas is injected into the cylinder, then the cylinder is sealed, and the processed and manufactured gas springs are accurate in pressure, stable in pressure value and high in safety.

The invention relates to a fine adjustment type cradle structure. The fine adjustment type cradle structure comprises a handle, a cradle body, a pressing mechanism and a locking mechanism, wherein a nut is fixed to the front parts of two locking sheets of the locking mechanism; a locking screw is mounted on the nut; a positioning block is mounted at the front lower part between the two locking sheets via a low connecting pin; the locking screw is jacked at the front part of the positioning block; a lug at the rear part of the positioning block is used for locking a V-shaped groove; a pressure fine adjustment mechanism is also arranged at the rear part of the handle; an adjusting bracket of the pressure fine adjustment mechanism comprises an adjusting seat arranged at the rear upper part of the handle and a connection plate arranged in a handle connector; the locking nut is fixed on the handle; a pressure adjusting screw penetrates through a mounting hole of a positioning spring, is screwed with the locking nut and is jacked at the front part of the adjusting seat; the rear part of the connection plate is articulated with the handle connector; a roller sleeve pin is mounted at the front lower part of the connection plate. The fine adjustment type cradle structure is convenient and rapid to mount and adjust, is integrated with functions of locking and adjusting the pressure, and is capable of reliably adjusting the pressure; the problem of automatic pressure release is solved.

The invention discloses a pressure device of a calendaring machine, and relates to the field of calendaring machines. The pressure device comprises a supporting frame and a self-pressing device; the supporting frame is fixedly connected to a machine base of a main calendaring machine, and the self-pressing device is fixedly connected to the supporting frame; the self-pressing device comprises a pneumatic mechanism and a pressurizing mechanism; the pneumatic mechanism comprises an airbag, a first connection pipe and an inflation pump, one end of the first collection pipe is communicated with aninternal cavity of the airbag, and the other end of the first connection pipe is connected with the inflation pump; the pressurizing mechanism is arranged over an upper roller of the main calendaringmachine body, and the airbag presses the upper roller of the main calendaring machine body through the pressurizing mechanism. The pressure device has the advantages that a pressure transfer chain issaved, a pressure value of the calendaring machine is more stable, and the qualification rate of glass is increased.

The invention discloses a pressure stabilizing automatic regulating system of a coke oven gas collector and a regulating method thereof, and can stably control a coke oven gas export system. The pressure stabilizing automatic regulating system comprises a coal charging section electric control valve used for regulating pressure in a coal charging section gas collecting tube, a communication valveused for regulating pressure in a large circulation pipe, a first-stage computer system and a second-stage computer system, wherein the first-stage computer system comprises a DCS control system, a field sensor and an actuating mechanism and is used for realizing field level distributed control; the second-stage computer system regulates the opening of the coal charging section electric control valve and the opening of the communication valve according to the pressure in the coal charging section gas collecting tube.

The invention discloses a single-phase variable-frequency air compressor, the machine head is fixed in a horizontal oil separator cylinder, the bottom of the horizontal oil separator cylinder and the main motor are fixed with a mounting plate, the mounting plate is fixed at the bottom inside the protective frame, and the machine head It includes a male rotor, a female rotor and a housing. The male rotor and the female rotor are meshed in parallel with each other. Both the male rotor and the female rotor are located in the housing, and both ends of the male rotor and the female rotor are connected to the housing through bearings. The male rotor includes Helical teeth, the female rotor includes a helical groove, and the relative movement between the helical groove and the helical teeth forms a volume chamber with variable volume. The output end of the main motor is fixed with a main pulley, and one end of the male rotor is fixed with a secondary pulley. The frequency conversion speed regulating device includes pressure Sensors and control components, the pressure sensor is fixed in the volume cavity, and the control component is fixed at the bottom inside the protective frame. The invention responds to changes in system pressure in a timely manner, maintains a stable system pressure value, regulates speed smoothly and reduces energy consumption.

The invention discloses a combustion device for a smoke sprayer on a plant protection unmanned aerial vehicle, and relates to the technical field of smoke sprayers. The combustion device comprises a fuel tank and a combustion mechanism, the combustion mechanism comprises a combustion nozzle, a spray pipe, a metal pipe and an electronic igniter, the metal pipe surrounds the spray pipe in the axialdirection, and the metal pipe is provided with a bent part located right in front of the end of the spray pipe; and the fuel tank is in an inverted state with a downward opening, a first one-way valveis arranged at one end of a fixing connector, a pressure regulating valve is arranged at one end of the first one-way valve, and a second one-way valve is arranged at one end of the pressure regulating valve. According to the combustion device, electric energy of the unmanned aerial vehicle does not need to be continuously used, and the power and working efficiency of the unmanned aerial vehicleare improved; inverted vaporizing combustion is adopted, and the heating effect on a heating spiral pipe is guaranteed; and the pressure regulating valve can regulate the pressure to ensure that the pressure value of liquid fuel from the fuel tank is stable, and the pesticide spraying effect is improved.

The invention discloses an aluminum alloy closed hydraulic nut for a circular disc shear, which is used for locking a shear blade of the circular disc shear. Body threads on a nut body are in clearance fit to a circular disc shear shaft, a gasket is attached to a shaft shoulder of the circular disc shear shaft, a circular disc cutter is arranged between the gasket and a spacer, an aluminum alloy hydraulic nut locks the circular disc cutter on the circular disc shear shaft through the spacer, the spacer is pressed by a pressing ring, and a spigot of the pressing ring is attached to the end surface of an annular groove of the nut body; the nut body is made of an aluminum alloy material, three plunger assemblies and one indicating rod assembly are tangentially distributed in the nut body, anoil filling nozzle, which is mounted on the nut body and connected to one hole of annular groove oil holes, communicates with plunger oil holes of the three plunger assemblies and an indicating rod oil hole, and the three plunger oil holes communicate with one another; a closed hydraulic nut structure is formed among the plunger oil holes, the indicating rod oil hole and the nut body, and a plug connected to a second annular groove oil hole is mounted on the nut body. The aluminum alloy closed hydraulic nut is light in weight, convenient and fast to assemble and disassemble, stable in intra-cavity pressure value and uniform in locking force.

The invention discloses a multi-differential-pressure type multiple high-pressure gas cylinder safety protection device. A mechanical shell, a solenoid valve shell and a multi-differential-pressure type structural shell are welded together. The mechanical shell is connected with a high-pressure gas cylinder. A solenoid valve element in the solenoid valve shell is of a wedge-shaped multi-level sealing structure. The multi-differential-pressure type structural shell is of a multi-differential-pressure type structure. According to the multi-differential-pressure type multiple high-pressure gas cylinder safety protection device, electronic control mechanical set is conducted through a solenoid valve and the multiple levels of sealing structures; mechanical set is conducted on the basis of thedifferential pressure principle of a front working cavity and a rear working cavity of a mechanical valve body, dual set protection is achieved, the structure is more stable, safe and reliable; an electromechanical dual protection structure formed by the multi-differential-pressure type structure and the solenoid valve is adopted, autonomous set of a mechanical structure and electronic control setof the solenoid valve are protected; the pressure value of gas in a gas channel is guaranteed to be a stable value; and motion of the mechanical structure is guaranteed.