86 results about "Pressure work" patented technology

The application belongs to the technical field of numerical control processing, in particular to a turning equipment for precise metal structural parts, which comprises an adjusting part, a modified seat, an annular metal part arranged at the axis of the upper surface of the modified seat, a rotating part arranged in the interior of the modified seat and used for twisting the placed annular metal part, and a butt joint part arranged at the axis of the modified seat. The device modifies the modified seat of the bearing metal part, so that the counterweight shaft cylinder can drive the heavy metal part to rotate centrifugally without being blocked by friction due to excessive pressure, thus avoiding the problems of serious wear or difficulty in rotation of the bottom of the counterweight shaft cylinder. Since the mass of the metal part is large and the rotational inertia is also large, a certain time is needed for deceleration and stopping. At this time, the lower pressure suction cylinder can perform suction and pressure work on the annular rotating groove, and the embedded rolling ball applies resistance to the rotation of the counterweight shaft cylinder, thereby promoting the deceleration of the metal part and reducing the adverse effects caused by inertia.

The invention relates to the technical field of oil and gas wellhead sealing equipment in the field of petroleum engineering, and discloses an oil and gas wellhead rotary sealing device suitable for workover treatment. The device consists of a bottom flange, a self-sealing middle body, a central pipe, a rotor upper body, a thrust bearing, a tapered roller bearing, a deep groove ball bearing, a lower rubber ring, an upper rubber ring, an upper rubber ring compression ring, a lower rubber ring compression ring, a gland and a positioning pin, is simple in structure, small in size and light in weight, adopts an integrated design, reduces redundant parts, is compact in overall structure, is convenient to mount and carry on site, and is convenient to maintain and maintain. The load burden of a wellhead is reduced; the sealing pressure is small, the sealing performance is good, reliable sealing can be achieved under the low pre-tightening pressure through the synergistic effect of mechanical pre-sealing and hydraulic sealing, and the sealing stability under the high-pressure working condition is effectively improved through the double-sealing mode; due to the design of the three-bearing structure and the detachable central pipe, the operation stability of the device under the complex working conditions of rotation, drilling and the like is guaranteed.

The invention provides a pressure sensing system compensation method and system, and the method comprises the steps: building a mathematical fitting model of an input and output pressure difference value and time under different conditions through testing and processing the data of a system in a starting time period under different input pressure and working temperature conditions, obtaining an initial environment condition when the system is started, and carrying out the calculation of the initial environment condition after the initial environment condition is obtained; and a corresponding mathematical fitting model is substituted to compensate the output pressure, so that the accurate pressure value in the system starting time period can be quickly calculated, and the performance improvement in the whole time period after the system is started is realized. According to the technical scheme, the technical problem that in the prior art, the pressure measurement precision deviation is large due to the fact that a thermal field is unbalanced in the starting period of a pressure sensing system is solved.

The utility model discloses a header welding device which comprises a fixing seat and a base, the top of the fixing seat is fixedly connected with welding equipment, the left side of the welding equipment is fixedly connected with a welding head, the center of the top of an inner cavity of the base is fixedly connected with a damper, and the bottom of the damper is fixedly connected with a pressure buffering plate. According to the header welding device, the device can be moved through the moving wheels, the time of manually carrying the device by workers is saved, the working efficiency of the workers is improved, a pressure buffering plate is conveniently driven to start pressure buffering through a damper, and the pressure buffering plate drives a sliding sleeve and a shaft rod to start pressure buffering work; and meanwhile, a sliding sleeve drives a sliding plate to start to slow pressure, and the sliding plate drives a spring to start to slow pressure, so that the shaking force generated by a bumpy road surface in the moving process of the moving wheel is effectively relieved, and the moving stability of the equipment is improved.

The utility model relates to the technical field of press machines, in particular to a hydraulic machine for manufacturing and processing automobile parts, which comprises a main body, a loading component is arranged at the top of the main body, and a pressure applying component is arranged on the side surface of the loading component; the gear on the side face of the electric hydraulic roller is meshed with the rack on the side face of the pressure rod, then the bottom end of the pressure rod exerts pressure on an object, and the press machine has the advantages of being easy to operate, wide in stroke range, completely adjustable in stroke and height position, small in operating force, large in pressure and high in working efficiency. Due to the fact that the electric press is driven by an electric motor to press downwards, an operator can use the minimum pressing force to meet the requirement for part pressing, the damping rod, the spring and the limiting end can guarantee that the electric press cannot crush a workpiece due to too large pressure, and convenience can be provided for disassembly and assembly of the press through the first clamping hoop, the second clamping hoop and the third clamping hoop.

The application discloses a kind of production process of PTFE pipeline of resistant vacuum steel lining, specifically includes the following steps: S1, steel lining welding, steel lining includes steel net and multiple steel bars, steel net, steel bar is formed by welding in the pipe wall of pipe body and is formed into prefabricated pipeline with steel lining;S2, PTFE inner lining blank isostatic pressing forming, the setting of steel lining in the application, increase the strength of PTFE inner lining, improve its anti-negative pressure capacity, so that PTFE pipeline can be better applicable to negative pressure working condition field, steel bar is positioned evenly in the pipe body with steel net, so that the interval between the outer periphery of steel net and the inner wall of pipe body is kept uniform, to ensure that the position of steel lining in PTFE inner lining is accurate, the thickness of PTFE inner lining after forming can keep consistent, guarantee its anti-negative pressure effect, core mould supports soft silica gel mould, so that the deformation of silica gel mould under the action of water pressure can be more uniform, to ensure the thickness of PTFE inner lining is uniform.

The invention provides an engine lubricating system, an engine and a vehicle, and relates to the technical field of engines. The crankcase has a negative pressure working condition and a positive pressure working condition, and is isolated from the oil pool box under the negative pressure working condition so as to perform negative pressure defoaming on lubricating oil in the crankcase; the oil pump is communicated with the oil pool tank under the positive pressure working condition so as to accelerate discharge of lubricating oil in the oil pump to the oil pool tank; the defoaming system utilizes the negative pressure working condition and the positive pressure working condition to conduct defoaming treatment on bubbles in the crankcase, the content of the bubbles in lubricating oil is reduced, and the service life of an engine is prolonged.

The invention discloses a method and tool for detecting the internal pressure of a shock absorber, the tool comprises a shock absorber body, the shock absorber body is composed of an oil storage cylinder, a working cylinder, a middle cylinder, a guider, an oil seal and a bottom valve, and the shock absorber body is provided with a pressure detector assembly. According to the invention, a pressure detection assembly composed of four pressure detectors is accurately arranged on core function devices such as a shock absorber oil seal, a guider, the middle part of an oil storage cylinder and a bottom valve, so that the limitation that only single-position static pressure detection can be realized in the prior art is broken through, and the shock absorber can be accurately detected under actual working conditions of stretching, compression and the like. Through real-time acquisition and synchronous monitoring of internal multi-key area pressure data, core detection dimensions such as oil seal gas sealing lip pressure, upper and lower pressure of a working cylinder and internal pressure of an oil storage cylinder are fully covered, and the technical blank of multi-position pressure cooperative detection of a shock absorber under a dynamic working condition in the industry is filled. And a more systematic and more accurate pressure data support is provided for performance optimization of the shock absorber.

The invention relates to a lower plastic part and cover plate assembly, comprising a plastic part main body mounted between a cover plate and a battery cell; an anti-explosion valve is arranged on the cover plate, and a supporting part is arranged on the plastic part main body; part of the supporting piece is located between the plastic piece body and the anti-explosion valve, and the supporting piece is used for supporting the anti-explosion valve. The lower plastic part is a part between the battery cover plate and the battery cell, and the supporting part is located on the side, facing the anti-explosion valve, of the plastic part body and used for supporting the anti-explosion valve. The supporting piece can be designed into a single type, an independent type or a mixed type, the top end attaching part is a smooth plane, all the attaching parts are kept on the same horizontal plane, and uniform supporting is achieved. Reverse support is provided under the negative pressure working conditions of vacuumizing, liquid injection and the like, unexpected sinking of the anti-explosion valve, especially a nick and thinned weak area is prevented, meanwhile, the fracture pressure relief function of the anti-explosion valve under the abnormal high pressure is not intervened, it is guaranteed that the anti-explosion valve can be fractured along a preset path when the anti-explosion valve is abnormal, and gas can be rapidly exhausted.

The invention discloses thin-wall stainless steel water supply pipe ring pressing type connecting and installing construction equipment and method, and relates to the technical field of pipe fitting connection. The method comprises the following steps that the end of a pipe and an external cylindrical sealing material are inserted into a pipe fitting, and air pressure borne by the end face of a sliding block is limited; the on-off valve is closed to limit the initial air pressure in the air cylinder and the air cylinder, the direction of the annular pressure head is corrected, the air pump is started, and after the air pressure reaches an annular pressure air pressure threshold value, annular pressure work of the water pipe is completed. Deformation of the water pipe under the action of unbalanced force is avoided, the annular pressure effect is improved, annular pressure errors caused by abrasion loss of the annular pressure head are made up, the annular pressure precision is improved, the trouble of frequent replacement of the clamp seat and the annular pressure head is solved, the convenience of annular pressure work is improved, the directions of the pipe, the pipe fitting and the annular pressure head can be corrected and limited, and the effectiveness of the annular pressure work is guaranteed.

The present application aims at providing a turbine blade reverse rotation air blowing loss measuring method, two turbine test pieces are designed, one turbine test piece is provided with a complete set of double-layer turbine blades, and a partition structure is used to block air from passing through the reverse rotation channel, and the other turbine test piece is provided with only forward rotation blades without reverse rotation blades. During the test, under the same air source inlet parameters, compressed air is used to drive the two turbine test pieces to rotate respectively, and the output power is measured, the output power of the reverse rotation turbine before modeling is obtained through a turbine modeling conversion relationship, the difference between the two output powers is the air blowing loss generated by the reverse rotation of the reverse rotation blades, and the influence of the structural size, gas temperature, gas pressure, working speed and other parameters on the reverse rotation air blowing loss of the turbine blade is obtained through finite element simulation calculation. The present application can solve the problem of measuring the reverse rotation air blowing loss of the double-layer turbine blade, and is an air blowing loss measuring method with simple operation and high measuring accuracy.

The application relates to the technical field of hydraulic transmission control, and discloses a method and system for driving and controlling a plunger pump by a servo motor, wherein the method for driving and controlling the plunger pump by the servo motor comprises the following steps: obtaining initialization data and equipment configuration parameters of a servo motor control system; performing hardware state detection and pressure working condition parameter configuration through a controller; establishing a quantitative relationship between the rotating speed of the servo motor and the output flow of the plunger pump; performing pressure working condition identification and mode switching, and verifying the working characteristics of the plunger pump; performing solenoid pulse width modulation control; determining a current working mode, performing mode-specific rotating speed strategy formulation and proportional-integral-derivative parameter adaptive control; and performing multi-mode performance comparison and cooperation effect analysis; the application can intelligently identify pressure working condition changes and automatically perform smooth mode switching, thereby ensuring optimal control performance under different working conditions.

The invention provides an integrated vacuum controller compatible with positive and negative pressure input, which is applied to the technical field of vacuum controller equipment, and through a confluence plate, positive pressure inlet air is collected into the interior through the confluence plate to perform air inlet and locking work on a subsequent vacuum generation assembly; the first positive pressure air inlet is formed in one side of the confluence plate and is used for breaking air; the second positive pressure air inlet is formed in one side of the confluence plate and is used for generating vacuum; the problems that when an existing vacuum controller controls one or more vacuum generators, it is usually difficult to be compatible with the vacuum quantities and vacuum breaking quantities corresponding to the multiple vacuum generators, if a user wants to provide multiple negative pressure power sources, the multiple vacuum generators are needed, but the multiple vacuum generators cannot be bought and connected in a scattered mode one by one, and the user experience is poor are solved. Even if the wire harnesses are too many, the wire harnesses are troublesome and complex, but if the wire harnesses are combined together, the pneumatic balance can not solve the technical problem of corresponding negative pressure work.

To provide an earth bucket fly-prevention structure for caissons that can certainly prevent the incident of earth buckets' flying and a soil removal method applied in a pneumatic caisson construction method.SOLUTION: An earth bucket fly-prevention structure for caissons prevents an earth bucket from being pushed out with compressed air and then flying even when the compressed air in a high-pressure work space is released upon the encapsulating door of a material lock being damaged and flows into a material shaft. In the structure, the material shaft that is meant for an earth bucket transporting out the excavation soil excavated in the high-pressure work space to run through is a double-tube material shaft composed of an inner tube 2 and an outer tube 3. The aforesaid inner tube 2 of the double-tube material shaft has a slit part 2a formed on it that is capable of releasing the aforesaid compressed air from the inside of the shaft through the outside.SELECTED DRAWING: Figure 5

The utility model discloses a data line production metering device, which belongs to the technical field of data line production, comprises a base, and is characterized in that one end of the base is provided with a winding mechanism for taking up a data line, and the other end of the base is provided with a metering mechanism for measuring the take-up length of the data line; the data line production metering device has the beneficial effects that the data line production metering device with the two take-up stations can work without stopping the machine to disassemble a line roller and installing the other line roller, so that the production efficiency is improved; when the movable block is matched with the meter counting wheel to work, the data line can be well extruded, so that the data line is not easy to slide, the data line cannot be crushed, and the working requirement of the pressure of the meter counting wheel can be met; and the movement of the sliding plate can drive the pressing wheel and the meter counting wheel to linearly move back and forth, so that the data line is uniformly wound on the line roller.

The utility model is suitable for numerical control angle saw field provides a numerical control angle saw with pressure structure, include: numerical control angle saw main part, be used for saw cutting processing, including saw cutting platform and saw blade seat, saw blade seat rotation is installed in saw cutting platform side face, feed frame, symmetry is installed in saw cutting platform both sides, is used for feeding, two pressure assembly, be used for to saw cutting material's fixed, symmetry is located saw blade seat saw blade both sides, pressure assembly includes: mounting seat, fixed mounting is installed on saw cutting platform, its side face fixed mounting has a plurality of hydraulic cylinders, pressure seat, fixed mounting is installed in the telescopic link end part in hydraulic cylinder. The utility model is through two pressure assembly of symmetrical setting to saw cutting material carries out pressure fixed, and carries out saw cutting through the saw blade seat of setting, compares with current numerical control angle saw, need not extra use pressure tool, and based on setting hydraulic cylinder, automatic pressure work is carried out, pressure speed is fast, and pressure effect is better.

The application discloses a compressed oxygen switch pressure reducer flow automatic detection device, and relates to the technical field of compressed oxygen equipment detection.The device takes the latest national standard of the isolated compressed oxygen self-rescuer as the design basis, and aims to solve the problems of low detection efficiency, large result determination error and dependence on manual operation in the process of detecting the flow of the existing compressed oxygen switch pressure reducer.The device can realize the flow detection of the switch pressure reducer under 20MPa high pressure working condition and 5MPa low pressure working condition through the construction of a multi-channel test gas path, and can automatically complete the classification of the detection results through four channels based on the preset standard, wherein only the products with the flow of 1.5L / min under 20MPa high pressure and the flow of 1.2-1.5L / min under 5MPa low pressure are determined as qualified, and the rest are classified into the unqualified channel.The application realizes the automation of flow detection and sorting, improves the detection accuracy and efficiency, and meets the quality control requirements in the production process of the isolated compressed oxygen self-rescuer.

This utility model discloses a relay oil flow measurement device, including a measuring device and a pressure flange disposed at both ends of the top of the relay. The relay includes a relay piston, a relay cylinder, a relay rear end cover, and a relay front end cover. The measuring device and the pressure flange are respectively connected to the relay rear end cover and the relay front end cover. The oil flow measurement device also includes a pressure device, the output end of which is connected to the measuring device and the pressure flange. The beneficial effect of this utility model is that the device can also be used for relay pressure work and driving the relay piston movement. The device can accurately measure the oil flow between the relay piston and the cylinder, providing a test measurement means for relay maintenance quality.

The utility model discloses an elastic sealing device for a horizontal split of a steam turbine cylinder. The elastic sealing device comprises a first elastic sealing ring and a second elastic sealing ring, the screws are used for fixing the first elastic sealing ring and the second elastic sealing ring in the threaded holes of the lower half part of the cylinder; a sealing groove is formed in the cylinder upper half; according to the design of the depth H of the sealing groove, when the upper half cylinder and the lower half cylinder of the air cylinder are closed, the first elastic sealing ring is compressed to 90%-95% of the original thickness, and pre-tightening sealing is formed; the inner side of the first elastic sealing ring and the inner side of the second elastic sealing ring make contact with the cylinder upper half to form a stepped sealing face used for triggering secondary sealing through pressure difference when a high-pressure working medium leaks. The sealing device can be applied to sealing of the horizontal split of the upper half and the lower half of the steam chamber of the steam turbine, internal leakage of a steam turbine set is reduced, the set efficiency is improved, the sealing device does not need to depend on tightening force for sealing, the good sealing effect can be achieved by means of self-weight press fit and internal and external pressure difference, and the use scene is wider.

The utility model discloses an automatic drilling clamp, including base, the top of base is fixed with drilling mechanism, the top of base is fixed with work table relative to the bottom of drilling mechanism, the top of work table is provided with self -adaptation clamping mechanism, the top of base is provided with drilling anti - splash mechanism, the utility model discloses the telescopic link and telescopic spring constitute elastic clamping subassembly through the design, make clamping board can move horizontally, and automatically adapt work piece width, and cooperate the design of auxiliary clamping side board and drive hydraulic ram longitudinal sliding through the cylinder, cooperate sliding block and sliding slot guide structure, realize the self -adaptation clamping of work piece length, finally cooperate the elastic reset of pressure block through built -in spring rod, utilize the automatic lifting of bevel surface design when contacting work piece and press down locking, avoid damaging work piece surface, have reached the effect of auxiliary pressure work piece, compared with prior art, greatly facilitated the clamping work of work piece.

The embodiment of the application relates to the technical field of heat pump, and specifically provides a control method of a heat pump system, a computer readable storage medium and computer equipment, the control method comprises: opening the first control valve, so that: a part of working medium circulates through an exhaust port of the compressor - a first-stage condenser pipeline - a first working medium branch - a throttling element - an evaporator - a second heat accumulator pipeline - a suction port of the compressor; another part of working medium circulates through the exhaust port of the compressor - the first-stage condenser pipeline - the first control valve - a first heat accumulator pipeline - the throttling element - the evaporator - the second heat accumulator pipeline - the suction port of the compressor; so that: the condensation heat recovered by the first heat accumulator pipeline heats the low-pressure working medium flowing through the second heat accumulator pipeline. Through such a structure, the performance of the heat pump system can be improved.

The utility model relates to the technical field of extruders, in particular to a reduction gearbox structure for an extruder with double output shafts. Comprising a box body, a first gear rod arranged on the box body, a transmission gear meshed with the first gear rod, a second gear rod arranged on the transmission gear, a first output assembly and a second output assembly which are meshed with the second gear rod, and a third gear rod which is in transmission connection with the first output assembly and the second output assembly, the second gear rod and the third gear rod are arranged at intervals, a first connecting sleeve is arranged at the end, away from the transmission gear, of the second gear rod, a second connecting sleeve is arranged at the end, away from the first output assembly and the second output assembly, of the third gear rod, and the first connecting sleeve and the second connecting sleeve are both used for being connected with an external extrusion screw. The structure is compact, design is reasonable, the number of transmission components is effectively reduced, installation is convenient, occupied space is reduced, transmission reliability and transmission efficiency are improved, and the working requirement for extrusion pressure of the extrusion screw is met.

The application discloses a heat engine working medium compressor performance test system and method, which comprises a total control module, a working medium control module, a heat engine working medium compressor and a driving module; wherein the total control module is connected with the rest modules respectively, is used for controlling the working state of each module, and collects real-time data; the working medium control module is used for receiving high-pressure working medium compressed by the heat engine working medium compressor, and inputting low-pressure working medium to the heat engine working medium compressor; the heat engine working medium compressor is used for pressurizing the working medium in the low-pressure working medium bottle and making the working medium enter the high-pressure working medium bottle; the driving module is used for providing power for the compression cycle of the heat engine working medium compressor, and is also used for measuring the rotating speed and torque of the heat engine working medium compressor. When the performance test is performed, the total control module controls the opening or closing of an exhaust electromagnetic valve, an intake electromagnetic valve and a short-circuit electromagnetic valve. The maximum torque of the working medium compressor is measured, the power consumption is calculated, and whether the performance test is qualified is judged.

The utility model relates to the technical field of sheet metal processing equipment, in particular to a nut welding machine for sheet metal parts, which comprises a cross-shaped sliding table, a nut pushing mechanism and a welding machine. A first positioning mechanism, a second positioning mechanism and a pressing mechanism are arranged on the cross-shaped sliding table; the nut pushing mechanism is used for pushing the nuts to the clamping station; the welding machine comprises a clamping mechanism, a third positioning mechanism and a welding mechanism. The workpiece is pressed through the pressing mechanism, and accurate positioning of the workpiece is guaranteed through the two positioning mechanisms; nuts can be automatically pushed through the nut pushing mechanism, and the nut pushing mechanism is matched with the clamping mechanism and the welding mechanism on the welding machine to achieve automatic clamping, placing and welding of the nuts; and a third positioning mechanism on the welding machine is utilized to avoid position deviation of the workpiece and ensure accurate welding. According to the nut welding machine for the sheet metal part, manual nut welding operation can be completely replaced through mechanical and automatic design, the nut welding quality and the working efficiency are improved, and the labor cost is reduced.

The utility model discloses a coupling flexible member axial rigidity measuring device, and specifically relates to the coupling flexible member rigidity measuring technology field, the coupling flexible member axial rigidity measuring device comprises a detection seat, two sides of the top of the detection seat are fixedly provided with support plates, electric push rods fixedly penetrate through the two support plates, and piston rods of the electric push rods are fixedly provided with connecting plates; the connecting plates are connected with connecting shafts used for placing couplings, measuring assemblies are fixedly arranged on the sides, close to each other, of the two supporting plates, and the outer walls of the two connecting shafts are sleeved with positioning plates. The coupling flexible piece is fixed through the two positioning plates and the two connecting shafts, the displacement distance is measured through the laser range finder, the pressure is measured through the pressure sensor, a worker analyzes and calculates the displacement distance and pressure data, the axial rigidity of the coupling flexible piece is obtained, and meanwhile the axial rigidity of the coupling flexible piece is measured. The measuring pen at the bottom of the positioning plate draws a path on the surface of the identification plate, so that follow-up workers can conveniently check the axial change of the coupler flexible part.

The utility model discloses an oil pipe under-pressure operation protector for an oil well, which comprises a mounting component fixed on the surface of an oil pipe body and a pressure gauge arranged at the top end of the mounting component, a connecting mechanism is arranged between the pressure gauge and the mounting component, and the connecting mechanism consists of a connecting component, a mounting flange and a mounting seat. The mounting flange is fixed at the bottom end of the pressure gauge, the mounting seat is arranged at the top end of the mounting assembly, and the connecting assembly is arranged at the joint of the mounting flange and the mounting seat; by means of the designed connecting mechanism, the phenomenon that an original pressure gauge is connected only through threads in the installation process, and installation is unstable is improved, the connecting mechanism is arranged between the pressure gauge and the installation assembly on the oil pipe body, the pressure gauge and the installation assembly are installed through the connecting mechanism, and under the condition that convenient operation is guaranteed, the installation efficiency is improved. The use stability and the sealing performance after connection are improved, and the accuracy of the value tested by the pressure gauge is ensured.

The external carbon brush structure of the electric hammer relates to the technical field of electric tools and comprises an electric hammer body and a protective shell, the electric hammer body is fixedly installed inside the protective shell, a motor is arranged at one end of the electric hammer body, a shell fixing frame is fixedly installed on the inner wall of the protective shell, and butt joint assemblies are arranged on the two sides of the shell fixing frame. The butt joint assembly comprises a sleeve, a connecting cylinder and a fixing cylinder, a spring groove is formed in the inner wall of the connecting cylinder, a sliding groove is formed in the inner wall of the fixing cylinder, and a carbon brush is arranged in the sliding groove; through mutual cooperation of the electric hammer body, the protective shell, the motor, the shell fixing frame, the connecting plate, the butt joint assembly and the cap, after a worker rotates the cap, the cap can be directly taken down, meanwhile, the compression spring releases pressure, the worker can directly pour the carbon brush out of the sleeve and can also manually take out the carbon brush, and when a new carbon brush is installed, the worker can conveniently and rapidly install the carbon brush. And the spring grooves and the sliding grooves can limit the carbon brushes, so that the replacement efficiency of the carbon brushes is reduced, and the applicability is high.

The application discloses an electric loader hydraulic system and an electric loader. In the system, a working pump drives a boom cylinder and a bucket cylinder through a distribution valve, a steering pump drives a steering cylinder through a flow amplification valve, and an oil port PF of the flow amplification valve is connected with an outlet of the working pump. An outlet of a pilot oil source valve is connected with an inlet of a steering gear. A controller collects pilot pressures of each control port of the distribution valve, an outlet pressure of the working pump, a rotation angular velocity of the steering gear, and matches a displacement of the working pump with a rotation speed of a working pump hydraulic motor, matches a handle opening degree with the displacement of the working pump and the rotation speed of the working pump hydraulic motor, and matches the rotation angular velocity of the steering gear with a displacement of the steering pump and a rotation speed of a steering pump hydraulic motor, so as to realize positive flow control of the hydraulic system, ensure that the working pump hydraulic motor, the steering pump hydraulic motor, the working pump and the steering pump always operate in an efficient interval, reduce energy loss, and realize energy-saving effect of the electric loader.

The invention relates to a hydraulic steering unit comprising a supply port arrangement configured to supply a hydraulic working pressure to a steering machine via a working flow path arrangement. The working flow path arrangement includes at least a first working flow path having a first port configured to be fluidly connected to the steering machine and a second working flow path having a second port configured to be fluidly connected to the steering machine. Further, the measurement motor is arranged in one of the working flow paths of the working flow path arrangement. Further, the working flow path arrangement is configured to supply a hydraulic assist pressure provided by the measurement motor via each of the ports when the hydraulic working pressure is below a predetermined threshold. In order to provide an improved hydraulic steering unit, an auxiliary flow path is formed between the first working flow path and the second working flow path when the hydraulic working pressure is below a predetermined threshold.

The application provides a blood pressure simulator calibration device, which comprises a box body, a detection port on the box body, the detection port being used for connecting a simulator to be calibrated, a gas path module, a measurement module and a control module connected in sequence in the box body, the gas path module being used for selecting different working gas paths to generate a gas pressure signal according to an instruction sent by the control module, the measurement module being used for monitoring a waveform of the gas pressure signal, the control module being used for sending an instruction to the gas path module in response to information of the simulator to be calibrated, adjusting the instruction according to the waveform of the gas pressure signal, and recording calibration data corresponding to the simulator to be calibrated, and the gas path module comprising a static pressure working gas path, a dynamic pressure working gas path, a leakage pressure working gas path and a gas capacitor. The calibration device of the application can automatically calibrate the blood pressure simulator, improve the accuracy of the calibration result, and has a high degree of integration and is convenient to carry.