183 results about "Maximum pressure" patented technology

The invention relates to the technical field of shield tunneling machine construction, in particular to a shield tunneling machine settlement control method which comprises the steps that the maximum pressure and the minimum pressure of a shield tunneling machine in an undercrossing subway tunnel section are calculated according to the burial depth and geological data, and when the shield tunneling machine conducts tunneling, the notch pressure of an excavation face is monitored according to the maximum pressure and the minimum pressure; in the tunneling process of the underpass subway tunnel section, the tunneling speed and the unearthing amount of a shield tunneling machine are monitored, meanwhile, grouting is conducted through radial holes in a shield shell by adopting a plastic material, and a gap, caused by excavation, between a soil body and the shield shell is filled; and when the shield tunneling machine tunnels to the granite layer, slurry injection parameters are controlled. According to the scheme, the safety and reliability of the construction process can be effectively controlled, the construction settlement condition is effectively controlled, it is guaranteed that the safety of the subway tunnel and the surrounding ground is effectively guaranteed, and related potential safety hazards are eliminated.

The invention discloses a marine high-pressure common rail diesel engine MPC combustion control method based on a physical informatization neural network, and belongs to the field of marine high-pressure common rail diesel engine control. The problems that physical consistency of a model and a real machine is ignored and the generalization ability of the model is poor due to the fact that only data driving is relied on are solved. The method comprises the following steps: keeping a combustion midpoint unchanged, and acquiring in-cylinder pressures, in-cylinder maximum pressure rise rates, indication heat efficiency and emission data of different pilot injection fuel ratios and pilot main injection positive time intervals; calculating the average indicated pressure circulation change of the diesel engine, screening data and calculating the accumulated heat release amount and the combustion midpoint; obtaining an influence rule of related characterization parameters of combustion in a diesel engine cylinder, and determining a crank angle corresponding to pilot injection timing, a pilot injection fuel ratio, a pilot main injection interval boundary and an upper limit of a maximum pressure rise rate of cylinder pressure; a diesel engine in-cylinder combustion prediction output model and an MPC controller are constructed; and updating control parameters and combustion state data to realize closed-loop control. The method is used in energy-saving and emission-reducing fields.

The application discloses a centrifugal air compressor surge control method, system, electronic equipment and storage medium, and the centrifugal air compressor surge control method comprises the following steps: obtaining the exhaust pressure variation intensity of a centrifugal air compressor; performing classified control according to the obtained exhaust pressure variation intensity value; when it is detected that the exhaust pressure variation intensity is less than a set maximum pressure variation threshold value and greater than a set minimum pressure variation threshold value, switching the anti-surge valve to an anti-surge automatic control mode; under the anti-surge automatic control, slowly opening the anti-surge valve to introduce airflow into the atmosphere and discharge the airflow; after continuously detecting that the exhaust pressure variation intensity is less than the set minimum pressure variation threshold value and maintaining the set time, switching the anti-surge valve out of the anti-surge automatic control mode and restoring the anti-surge valve to a normal control mode; and when it is detected that the exhaust pressure variation intensity is greater than the set maximum pressure variation threshold value, switching the anti-surge valve to a surge protection mode and switching to a surge fast-opening mode. The application can improve the stability of the centrifugal air compressor.

The invention relates to a method for controlling a hydraulic system (1) for a motor vehicle with an electrically operated pump (2) that regulates the system pressure, wherein the system pressure is controlled between a maximum pressure and an opening pressure to actuate a clutch (17) by means of a slave cylinder (6). To prevent damage to the hydraulic system (1) due to excessive system pressure, pressure values ​​of a pressure signal of the system pressure are statistically evaluated after exceeding the maximum pressure over a predetermined measurement interval, and an error is output if a predetermined probability of the pressure values ​​exceeding the maximum pressure is reached.

A dual-redundancy electro-hydrostatic actuator comprises a first motor pump and a second motor pump which are energy assemblies of the electro-hydrostatic actuator; the first motor pump and the second motor pump are respectively provided with a first electromagnetic isolating valve and a second electromagnetic isolating valve which are used for controlling connection and disconnection between the first motor pump and the hydraulic cylinder and between the second motor pump and the hydraulic cylinder; the energy accumulator is an oil supplementing assembly of the electro-hydrostatic actuator, provides stable pressure when the motor pump works at a high speed, and prevents the electro-hydrostatic actuator from sucking air; the one-way valve is located between the energy accumulator and the hydraulic cylinder, the energy accumulator supplies oil to the hydraulic cylinder through the one-way valve, and oil is prevented from reversely flowing back to the energy accumulator; the safety valve plays a role in limiting the maximum pressure of the electro-hydrostatic actuator, and the electro-hydrostatic actuator is prevented from being damaged due to the fact that the pressure exceeds the limit; the sensor is used for judging the working states of the first motor pump and the second motor pump of the electro-hydrostatic actuator, and after signals of the sensor are sent to the controller, the controller achieves fault diagnosis of the motor pumps and triggers updating of system state identifiers.

The invention relates to a method for setting the parameters of a control of a pressure supply system of a hydraulic system, wherein the pressure supply system has a motor (4) and a hydraulic machine (2) that are controlled with a manipulated variable, wherein the control (160) is implemented by a control algorithm, wherein the control algorithm is parameterised by one or more parameters that can be set or changed during operation, the method comprising: carrying out (110), during operation of the hydraulic system, an estimation method based on a physical model in order to determine an estimated value for at least one characteristic variable of the hydraulic system, wherein the at least one characteristic variable includes a hydraulic capacity of the hydraulic system; determining (120) an adjustment time constant as equal to or greater than a target time constant, by means of which a maximum pressure build-up rate of the hydraulic system is achieved, which is determined by the estimated value for the hydraulic capacity and a maximum volumetric flow rate of the hydraulic machine; setting (150) at least one parameter of the one or more parameters, wherein the at least one parameter is determined (130, 140) by a respective function dependent on the setting time constant.

The invention discloses a method for producing high alloy steel through continuous casting. The method comprises the steps that the specific water flow of a continuous casting billet of the high alloy steel at the pulling speed is reduced in the continuous casting billet production process; the roll gap of the driven roll in the fan-shaped section behind the light downward pressing section is set to be a parallel roll gap or an open roll gap, and the rolling reduction of the light downward pressing section is kept unchanged; and the maximum pressure of the first oil cylinder in the fan-shaped section behind the light downward pressing section is set to be 160 bar or below. The cooling strength of a continuous casting billet is reduced by reducing the specific water flow at each pulling speed of the continuous casting billet of high alloy steel in production, so that the temperature of the continuous casting billet is increased, and the strength of a billet shell and the continuous casting billet is reduced; by reducing the total rolling reduction of a fan-shaped section roll gap and the maximum pressure of a first oil cylinder, the positive pressure of the fan-shaped section on a blank shell and a continuous casting blank is reduced, and the average torque of a driving roll is reduced; the problem that the continuous casting billet cannot be pulled when the high alloy steel continuous casting billet is produced is solved, the occurrence rate that the continuous casting billet cannot be pulled is reduced to 0 time per furnace of molten steel, and the service life of the fan-shaped section is prolonged to more than 6500 furnaces of molten steel.

The invention provides a method for generating performance degradation data of a train air braking system. The method comprises the following steps: on the basis of a brake system of a preset model, analyzing three stages of pressure rise, maximum pressure and pressure stability of pressure change of a brake cylinder, and extracting a plurality of typical fault modes; based on an extended random process model with non-monotonicity and independent incremental property, three stages of pressure change of a brake cylinder and multiple typical fault modes are combined, and linear, nonlinear or stepped performance degradation process modeling of the train air brake system is carried out; overlapping normal distribution random noise on a performance degradation track generated by modeling, simulating a control precision error of an actual braking system, and optimizing a performance degradation process model of the train air braking system; and utilizing the train air braking system performance degradation process model to generate train air braking system performance degradation data in batches.

The present application relates to a kind of design methods of cementing annular slurry column, comprising the following steps: 1) collecting the leakage parameter of the weakest formation in the formation to be cemented, the leakage parameter of the second weakest formation, the bottom hole leakage parameter and the maximum formation pressure parameter;2) calculate the maximum pressure bearing parameter at the weakest formation when cementing operation is bumped, the maximum pressure bearing parameter at the second weakest formation when cementing operation is bumped, the maximum pressure parameter that bottom hole bears when cementing operation is bumped and the bottom hole pressure parameter when tail slurry gelatinization loses weight during cementing operation;3) according to the leakage parameter of the weakest formation, the leakage parameter of the second weakest formation, the bottom hole leakage parameter and the maximum formation pressure parameter, the maximum pressure bearing parameter at the weakest formation when cementing operation is bumped, the maximum pressure bearing parameter at the second weakest formation when cementing operation is bumped, the maximum pressure parameter that bottom hole bears when cementing operation is bumped and the bottom hole pressure parameter when tail slurry gelatinization loses weight during cementing operation, it is judged whether annular slurry column is designed reasonably.

The invention relates to the technical field of pressure reducing valves, and discloses a novel pressure reducing valve with two-stage pressure regulating precision, which comprises a pressure regulating valve assembly, a first-stage cylinder assembly and a second-stage cylinder assembly are sequentially arranged on the right side of the pressure regulating valve assembly, the pressure reducing valve assembly comprises a valve body and a valve core, and an oil supply port P, a pressure outlet A and an oil drainage port T are respectively formed in the side wall of the valve body. A pressure sensor is arranged at the pressure outlet A; the first-stage air cylinder assembly comprises a first-stage cylinder body and a first-stage piston, the second-stage air cylinder assembly comprises a second-stage cylinder body and a second-stage piston, the valve element, the first-stage piston and the second-stage piston are sequentially connected and coaxially arranged, and air sources are introduced into the left side and the right side of the first-stage piston and the left side and the right side of the second-stage piston respectively to control the valve element to move leftwards and rightwards. The oil supply port P, the pressure outlet A and the oil drainage port T are switched to be connected and disconnected, and the stress balance state of the left side and the right side of the valve element is achieved. According to the invention, the pressure can be adjusted from 0ba, the maximum pressure adjustment range is applied to 20bar, and accurate pressure adjustment can be realized in a small pressure range.

Disclosed is a method for depowdering a part (3) produced by additive manufacturing, the part comprising a cavity (15) to be depowdered, the cavity comprising a first opening (151), the method comprising steps of: a) pressurising the cavity by injecting a gas up to a predetermined maximum pressure through the first opening; b) suddenly releasing the pressure within the cavity by quickly switching from the predetermined maximum pressure to a purge pressure.

A pneumohydraulic pressure intensifier includes at least one pneumatic piston that is coupled to a hydraulic pump. The pressure intensifier includes a regulator which allows to set the hydraulic output pressure. The regulator is coupled to a hydraulic pilot control valve which is adapted to interrupt the air supply to the pneumatic piston when a set maximum pressure is reached.

The invention discloses a supercritical CO2 stable pressurization method based on compression factor change, which comprises the following steps: determining a temperature threshold value of exhaust temperature of each stage of pressurization according to pressurization parameters, and then setting the stage number to be pressurized, the exhaust pressure and the exhaust temperature of each stage and the intake temperature of the next stage; obtaining a change rate trend chart when the compression factor z changes along with the temperature and the pressure; according to the change rate trend chart, determining the change rule of the compression factor z along with the temperature under each stage of intake and exhaust pressure, and limiting the change range of the compression factor z within a set change rate range; secondly, an inter-stage temperature precise control system is arranged in the process from each stage of exhaust to next stage of air inlet, and the temperature is precisely controlled to be within the next stage of air inlet temperature fluctuation range set in the first step according to the change rate range set by the compression factor z and the temperature control limiting range. According to the invention, CO2 and CO2 mixed gas can be pressurized from a conventional gas state to a supercritical state, the highest pressure after pressurization can reach 50 MPa, and the high-pressure gas injection requirement of a CCUS project is met.

The invention discloses a hydrogen cost determination method and device of a hydrogen refueling station, a medium and electronic equipment. The method comprises the following steps: equally dividing a pressure interval from zero to maximum pressure of a hydrogen storage tank into a plurality of unit pressure intervals; at first time, determining first hydrogen mass and first hydrogen cost corresponding to the unit pressure interval; hydrogen fixed cost, hydrogen compressor parameters in a target time period and a time difference are obtained, the target time period is a time period from the first time to second time, the time difference is a difference value between the second time and the first time, and the second time is after the first time; and according to the first hydrogen mass, the first hydrogen cost, the hydrogen compressor parameters, the time difference and the hydrogen fixed cost, the second hydrogen cost corresponding to the unit pressure interval at the second time is determined. According to the invention, the hydrogen cost of the hydrogen refueling station can be accurately calculated.

Braking system for a vehicle with a master brake cylinder (2), a fluid control unit (3) and at least one wheel brake (4.1, to 4.4), wherein the fluid control unit (3) for brake pressure modulation of the at least one wheel brake (4.1 to 4.4) in at least one brake circuit (10, 20) comprises a switching valve (12, 22), a control valve (50A, 50B) and a return pump (15, 25) for each brake circuit (10, 20), wherein the control valves (50A, 50B) are each connected in a suction line between the corresponding return pump (15, 25) and the master brake cylinder (2) and limit the effective pressure at a suction side of the respective return pump (15, 25) to a predefinable maximum pressure value, wherein a first fluid port (51A, 51B) of the respective control valve (50A, 50B) is connected to the The master brake cylinder (2) and a second fluid connection (52A, 52B) of the respective control valve (50A, 50B) are coupled to the respective return pump (15, 25), characterized in thatthat a pressure-relieved port (53A, 53B) of the respective control valve (50A, 50B) is coupled to a fluid accumulator (16, 26), wherein the respective control valve (50A, 50B) comprises a longitudinally movable control piston (54) which is acted upon on the pressure-relieved side by an actuating spring (55) with a spring force and in an initial position completely opens a fluid connection between the first fluid port (51A, 51B) and the second fluid port (52A, 52B) with a maximum flow cross-section, wherein a pressure building up at the first fluid port (52A, 52B) moves the control piston (54) against the spring force of the actuating spring (55) in the direction of the pressure-relieved port (53A, 53B), wherein the flow cross-section of the fluid connection between the first fluid port (51B) and the second fluid port (52B) 52B) can be reduced by the movement of the control piston (54), wherein the fluid connection between the first fluid port (51A,51B) and the second fluid port (52A, 52B) is completely interrupted by a stop position at the specified maximum pressure value at the second fluid port (52A, 52B), and wherein the spring force of the actuating spring (55) moves the control piston (54) from the stop position back towards the starting position when the current pressure at the second fluid port (52A, 52B) falls below the maximum pressure value.

The application discloses a hydrogen production and hydrogenation integrated station control method, which comprises hydrogen production equipment, a hydrogen buffer tank, a first-stage compressor, a first-stage hydrogen storage tank, a second-stage compressor, a second-stage hydrogen storage tank and hydrogenation equipment which are sequentially connected; during hydrogenation, the hydrogen production equipment, the first-stage compressor, the second-stage compressor and the hydrogenation equipment are controlled to work according to the relationship between the pressures of the hydrogen buffer tank, the first-stage hydrogen storage tank, the second-stage hydrogen storage tank and the hydrogenation equipment when the hydrogenation equipment works and the maximum filling pressure allowed for the hydrogenation equipment, the first preset pressure, the second preset pressure, the maximum allowable working pressure of the second-stage hydrogen storage tank, the fourth preset pressure, the minimum inlet air pressure of the first-stage compressor, the maximum allowable working pressure of the first-stage hydrogen storage tank, the third preset pressure, the maximum allowable working pressure of the hydrogen buffer tank and the minimum inlet air pressure of the second-stage compressor. The application realizes on-demand start and stop of hydrogen production, reduces loss, prolongs the service life of equipment, reduces cost and production hidden danger.

One aspect of the present disclosure provides a method for controlling a multi-fuel engine system configured to use gaseous fuel and hydrogen, in which a maximum pressure and a combustion center of a cylinder may be detected while the multi-fuel engine system is operating, and a ratio of hydrogen to be mixed with the gaseous fuel may be determined based on the detected maximum pressure in the cylinder and the combustion center.

The invention relates to a forging return stroke electro-hydraulic system adopting discrete liquid volume units and a control method.The system comprises a plurality of oil tanks connected with a controlled pressure containing cavity in parallel at the same node, and the first end and the second end of each oil tank are connected with a reversing valve and a one-way valve correspondingly to form a volume unit capable of being independently gated; all the oil tanks jointly form a parallel oil tank group; the plunger type cylinder is connected with a node of the parallel oil tank set, oil in the plunger type cylinder flows into the return oil tank to be compressed when the hammer head enters, and oil in the return oil tank flows into the plunger type cylinder to provide return force for the hammer head when the hammer head retreats. According to the working frequency requirement, the forging force requirement and the oil elasticity modulus fluctuation condition of the hammer head, the return stroke oil tank is controlled to reach the maximum volume allowed by the working condition through the combination of discrete volume units, and meanwhile the set pressure of the system is adjusted according to the maximum pressure value of the plunger cavity; the pressure curve of the plunger cavity can cover the minimum return stroke pressure requirement in real time, and the return stroke requirements of the hammer head under various working conditions of different working frequencies, forging forces and different oil liquid elasticity moduli in a large range are met.

This invention provides a method and apparatus for detecting the reuse of centrifuge tubes in ultra-high-speed centrifuges, comprising the following steps: S1, pressurizing and filling a medium into a new centrifuge tube, and detecting the diameter deformation of the centrifuge tube online; S2, using the maximum pressure that the centrifuge tube can withstand to return to its initial diameter as the yield limit pressure value; S3, replacing the centrifuge tube to be reused, pressurizing and filling the centrifuge tube to be reused with a medium, controlling the reuse pressure value at 75%~95% of the yield limit pressure value; S4, detecting the diameter deformation of the centrifuge tube to be reused online; S5, selecting the centrifuge tube that can return to its initial diameter as the reuse centrifuge tube. This invention can detect centrifuge tubes and determine whether they can be safely reused, significantly reducing experimental costs. It can be used to detect whether replacement centrifuge tubes meet the application requirements of ultra-high-speed centrifuges. It prevents substandard centrifuge tubes from entering the ultra-high-speed centrifuge, causing equipment damage or even sample leakage.

The invention discloses a fuel gas block valve capable of resisting high-pressure burst, and relates to the technical field of fuel gas block valves, the fuel gas block valve comprises a main body valve, a pressure relief assembly is arranged on the inner wall of the main body valve, an automatic cut-off assembly is arranged on the inner wall of the main body valve, the pressure relief assembly comprises a main body column, and when the valve is closed, the automatic cut-off assembly is arranged on the inner wall of the main body valve. The main body column ascends to enable the small semicircular shielding ball to move downwards, the small semicircular shielding ball moves downwards so as to enable the small semicircular shielding ball to open shielding of the first sealing ring, and then the air pressure in the main body valve can act on the bottom face of the burst window conveniently, and when the air pressure in the main body valve rises abnormally and sharply, the burst window is opened. The bursting window is broken before the main body valve bears the maximum pressure impact limit, so that air pressure in the main body valve flows into the pressure relief cavity through the set air inlet hole, then the extreme pressure borne by the main body valve is relieved conveniently, and the probability that the main body valve bursts due to extreme high-pressure impact is reduced.

A test device and test method of an aircraft main wheel turning system. The aircraft main wheel turning system comprises a turning system crank, a turning actuating system, a turning system connecting rod and a turning shaft, which are installed on the test device, and one end of the turning system crank is fixedly connected with a support connecting piece of a turning system support; the upper end of the turning actuating system is hingedly connected with the other end of the turning system crank; the connecting rod connecting piece of the upper end of the turning system connecting rod is hingedly connected with the third end of the turning system crank, loading points are added on both sides of the turning center of the turning shaft, and clockwise rotation loading and counterclockwise rotation loading of the main wheel turning system are realized by switching the loading points, so that the loading mode of the conventional loading test bed is expanded. The maximum pressure and tension locking force of the aircraft main wheel turning system and the turning rate of the aircraft main wheel turning system can be tested by the aircraft main wheel turning system, the test requirements of the aircraft main wheel turning system are met, and the safe, reliable and efficient work of the aircraft main wheel turning system is ensured.

This invention discloses an intelligent crimping pressure monitoring system and method. The system includes a crimping machine, a pressure sensor, a data acquisition unit, and a data processing server. The pressure sensor collects pressure signals from the crimping mold in the crimping machine in real time. The data acquisition unit collects the pressure signals output by the pressure sensor during the crimping process at a high sampling rate and processes them to obtain the maximum pressure value. The data processing server acquires equipment information, current production order information, and the corresponding pressure standard range. It generates an alarm control signal when the maximum pressure value exceeds the pressure standard range, or generates crimping data when the maximum pressure value does not exceed the pressure standard range. This invention, by monitoring the maximum pressure value of the crimping machine in real time and automatically comparing it with the pressure standard range, can achieve abnormal alarms, facilitate timely detection of products with unqualified crimping pressure, ensure product quality, and enable quality traceability through crimping data.

The invention provides a maximum temperature and pressure measuring method for a temperature and pressure special-shaped sensor, and relates to the technical field of sensor testing. According to the method, the temperature and pressure special-shaped sensor is installed in an experiment system, and the maximum temperature value and the maximum pressure value are applied to the temperature and pressure special-shaped sensor through temperature and pressure control equipment, so that the sensor is in the maximum temperature and pressure condition; then obtaining a reflection spectrum signal of the sensor through a spectrograph, and demodulating the signal to obtain an optical path difference variable quantity; and finally, the measurement values of the sensor under the maximum temperature value and the maximum pressure value are determined according to the optical path difference variable quantity, systematic verification of the measurement capability of the temperature and pressure special-shaped sensor under the limiting working condition is realized, and a reliable means is provided for evaluating the actual performance of the sensor under the high-temperature and high-pressure environment.

The invention relates to the technical field of energetic material testing, and particularly discloses a method for testing volume cracking resistance of a high-energy solid propellant, which comprises the following steps: step 1, preparing a high-energy solid propellant volume cracking resistance test piece; 2, connecting the test piece with a gas storage tank in a sealed manner to form a sealed space; and 3, starting a pressurizing air pump of the air storage tank, recording the pressure of the sealed space, and completing the test when the maximum pressure value appears, so as to obtain the volume cracking resistance. The test method can quantitatively characterize the volume cracking resistance of the high-energy solid propellant, provides specific evaluation data for the volume cracking resistance of the solid propellant, and quantitatively characterizes the volume cracking resistance of the high-energy solid propellant through specific pressure values. The advantages and disadvantages of the volume cracking resistance of the solid propellants with different formulas can be tested.

The invention relates to a welding spot detection system and method, and relates to the technical field of welding spot detection. The connecting seat is arranged on the first side of the line moving box; the telescopic rod is fixedly connected between the line moving box and the connecting seat; the ultrasonic probe is arranged on the first side of the connecting seat; the spring seat is arranged on the first side of the connecting seat and connected with the connecting seat, the two ends of the spring are connected to the spring seat and the ultrasonic probe respectively, a pressure sensor is arranged in the spring seat, and the pressure sensor can detect the pressure of the spring; and the control module is coupled with the telescopic rod and the pressure sensor, and the control module can control the telescopic rod to stretch out and draw back according to a preset maximum pressure threshold value. The ultrasonic probe can be comprehensively and tightly attached to the target welding spot of the arc-shaped or special-shaped sheet metal part, the attaching gap caused by poor adaptability of a curved surface in a traditional technical scheme is eliminated, and the accuracy of detection data is guaranteed.

This invention provides a method and apparatus for measuring the dew point pressure of shale condensate gas, belonging to the field of natural gas extraction technology. The method includes: raising the temperature of a core holder to a preset temperature; injecting condensate gas into the core holder to a first preset pressure; after a preset time, reducing the pressure of the core holder to a second preset pressure according to a first preset change amount, while simultaneously acquiring the acoustic transit time of the core under different pressures; determining the dew point pressure range of shale condensate gas based on the acquired acoustic transit time; injecting condensate gas into the core holder to the maximum pressure value within the dew point pressure range; after a preset time, reducing the pressure of the core holder to the minimum pressure value within the dew point pressure range according to a second preset change amount, while simultaneously acquiring the acoustic transit time of the core under different pressures; and determining the dew point pressure of the shale condensate gas based on the newly acquired acoustic transit time. This invention is simple to operate, provides accurate measurement results, and can provide a technical basis for the efficient development of shale condensate gas reservoirs.

A pressure pulse injector can include an accumulator, valves, and a control system. The control system can receive parameters, including a maximum pressure and target distance, about a flowline. The control system can determine a change in pressure for a pressure pulse based on the parameters. The control system can determine a pressurization level for fluid in the accumulator. The control system can transmit the pressure pulse into the flowline. The control system can determine, using a reflected pressure pulse, information about an anomaly in the flowline.

A pneumohydraulic pressure intensifier includes at least one pneumatic piston that is coupled to a hydraulic pump. The pressure intensifier includes a regulator which allows to set the hydraulic output pressure. The regulator is coupled to a hydraulic pilot control valve which is adapted to interrupt the air supply to the pneumatic piston when a set maximum pressure is reached.

The invention discloses a hydraulic control system and method for free switching of high impact and low impact of a drill jumbo and relates to the field of engineering machine.The hydraulic control system comprises a pump assembly, an oil outlet valve set, a main reversing valve and a pressure limiting valve set. When the main reversing valve is located at the first station, the pressure limiting valve set sets the standby pressure of the hydraulic control system to the overflow pressure value of the third overflow valve, the pump assembly maintains the minimum flow output, when the main reversing valve is located at the second station, the highest impact pressure is limited to the overflow pressure value of the first overflow valve, and the pump assembly is suitable for tapping and soft rock working conditions, and when the main reversing valve is located at the third station, the highest impact pressure is limited to the overflow pressure value of the second overflow valve. The impact pressure is limited to the overflow pressure value of the second overflow valve, the impact power of the drill jumbo is prevented from exceeding the limit, the drill jumbo is suitable for hard rock and deep hole working conditions, through cooperation of the control oil ports and the pressure limiting valve set, different highest system pressures are limited under different working conditions, segmented control over the high impact pressure and the low impact pressure can be achieved, and the working efficiency is improved.