CN106226045A - A kind of dry testing method for pressure limiting valve opening pressure and device - Google Patents

Abstract

The invention discloses a dry-type test method and device for the opening pressure of a pressure limiting valve; comprising a gas source, a pressure regulating valve, a proportional pressure reducing valve, a supercharger, a gas storage tank, a gas flow meter, a pressure sensor, and an inflatable two-way solenoid valve , exhaust two-way solenoid valve, electric control device; gas source, pressure regulating valve, proportional pressure reducing valve, supercharger, gas storage tank, gas flow meter, pressure sensor, and inflation two-way solenoid valve are connected in series in sequence; The exhaust two-way solenoid valve is connected to the pipeline between the gas storage tank and the gas flowmeter; the electric control device is electrically connected with the gas flowmeter, pressure sensor, inflation two-way solenoid valve, and exhaust two-way solenoid valve; The device is continuously pressurized and the pressure is constantly rising; the opening pressure detection of the pressure limiting valve is accurate and the repeatability is very high; it is very easy to detect the stuck pressure limiting valve or the upper limit pump; the test method is simple, the cost is extremely low, and the test period is very short. Short, does not affect product cleanliness index, good operating environment, convenient transportation.

Description

A dry test method and device for opening pressure of a pressure limiting valve

technical field

The invention belongs to the technical field of oil pump and metering detection, and relates to a dry test method and device for the opening pressure of a pressure limiting valve; in particular, it relates to a dry test method and device for the opening pressure of a pressure limiting valve of an oil pump, which is especially suitable for various forms of Steel ball and plunger oil pump pressure limiting valve detection.

Background technique

The traditional oil pump pressure limiting valve opening pressure test method uses oil as the test medium. Under the conditions of calibration test oil temperature, viscosity and speed, the regulating valve is used to control the calibration test pressure required by the oil pump product. When the regulating valve is closed, the oil pump will output oil. When the pressure at the port increases, when it is greater than the opening pressure of the pressure limiting valve, the pressure limiting valve opens, and at this time the opening pressure of the pressure limiting valve is obtained through the pressure transmitter. The traditional opening pressure test of the pressure limiting valve with oil as the medium has high test cost and slow pace. After the test, the product must be drained. After the test, there is still oil in the product, which will pollute the product to a certain extent. The product is clean It is difficult to achieve the high-speed index, which brings inconvenience to storage, transportation, and user assembly and use.

The known CN1908609A pressure-limiting valve opening pressure dry test method is a dry-type test method and device for pressure-limiting valve opening pressure different from the present invention; The circuit is connected in parallel with the pressurized pipeline; the detection method is to pre-inflate the detected pressure limiting valve first, and the air pressure needs to be stable for 2-10 seconds after pre-inflating; make the pressure limiting valve reach sealing and achieve stable air pressure; then pressurize The pipeline pressurizes the cavity of the pressure limiting valve, and the gas pressurized by the pressurizing pipeline is quantitative; the pressurized gas acts on the plunger or steel ball of the pressure limiting valve. When the gas pressure is greater than the spring preload of the pressure limiting valve , the plunger or steel ball of the pressure limiting valve opens, and the pressure sensor detects the highest value of the air pressure at this time; Special circumstances such as pressure limiting valve leakage cannot be detected and judged.

Contents of the invention

The invention discloses a dry-type test method and device for the opening pressure of a pressure limiting valve to solve the problem of high test cost and slow beat in the prior art for the opening pressure test of a pressure limiting valve using oil as the medium, and the product needs to be drained after the test. During the process, there is still oil residue in the product after the oil is drained in the test, which will pollute the product to a certain extent, and the product cleanliness index is not easy to achieve, which brings inconvenience to storage, transportation, and user assembly and use; the dry test of the opening pressure of the pressure limiting valve is not good The movement displacement of the pressure limiting valve comes out; and the problem that the pressure limiting valve is stuck, but the pressure limiting valve has leakage and other special circumstances cannot be detected and judged.

The pressure limiting valve opening pressure dry test method of the present invention: use air or other gaseous gas as the medium, utilize the force of the pressure limiting valve spring and the gas pressure charged into the high pressure chamber of the oil pump to interact with each other and balance the principle; move through the pressure limiting valve body The opening pressure of the pressure limiting valve is determined by the change of the inflated gas volume when it reaches the open position. The gas volume is detected by the gas flowmeter in the inflated pipeline; before the test, the inflated two-way solenoid valve is connected to the standard sample pipeline, and the test device is calibrated ; During the test, the inflatable two-way solenoid valve is connected to the pressure limiting valve pipeline of the test piece.

include:

The first step is to detect the opening pressure of the pressure limiting valve:

Before the test, the exhaust two-way solenoid valve and the inflation two-way solenoid valve are closed; the proportional pressure reducing valve can stably adjust the pressure of the gas test medium passing through the pressure regulating valve to the initial pressure value to ensure a stable gas supply, and its value is lower than that of the pressure limiting valve The lower limit of the opening pressure; the pressure limiting valve of the test workpiece is sealed with the gas-filled two-way solenoid valve pipeline; when the test is started, the gas-filled two-way solenoid valve is opened, and the gas source is continuously pumped into the gas test medium; Accurate pressure regulation at a certain speed ratio through the proportional pressure reducing valve; the gas test medium output by the proportional pressure reducing valve is continuously pressurized to the gas storage tank through the supercharger; the gas test medium is passed through the gas storage tank, gas flowmeter, pressure sensor, The inflatable two-way solenoid valve inflates the pressure limiting valve of the test workpiece; the gas flowmeter detects the flow rate of the gas test medium; when the gas flowmeter detects that the flow rate of the gas test medium reaches the set flow value, the pressure value of the gas test medium detected by the pressure sensor is the limit value. Pressure valve opening pressure value.

The second step, exhaust and restore the initial:

The inflatable two-way solenoid valve is closed, the exhaust two-way solenoid valve is opened, and the gas test medium in the test device is exhausted through the exhaust two-way solenoid valve; when the pressure value of the gas test medium detected by the pressure sensor is lower than the initial pressure value, the exhaust The two-way solenoid valve is closed; the proportional pressure reducing valve restores the pressure of the gas test medium to the initial pressure value for the next test; to ensure the repeatability accuracy of the test.

The dry test method for the opening pressure of the pressure limiting valve of the present invention: the difference between the pressure value of the gas test medium adjusted by the proportional pressure reducing valve and the lower limit of the opening pressure of the pressure limiting valve is greater than or equal to 0.05 MPa.

The dry test method for the opening pressure of the pressure limiting valve of the present invention: before the detection of the pressure limiting valve of the test workpiece, it also includes the calibration of the opening pressure limit of the pressure sensor testing the pressure limiting valve; including:

Before calibration, the exhaust two-way solenoid valve and the inflation two-way solenoid valve are closed; the proportional pressure reducing valve can stably adjust the pressure of the gas test medium passing through the pressure regulating valve to the initial pressure value to ensure a stable gas source, and its value is lower than that of the pressure limiting valve The lower limit of the opening pressure; connect the standard sample of the opening pressure of the pressure limiting valve to the pipeline of the inflatable two-way solenoid valve; use the opening pressure limit of the pressure limiting valve of the calibration device; The gas test medium is continuously pumped; the gas test medium passing through the pressure regulating valve is precisely regulated at a certain speed ratio through the proportional pressure reducing valve; the gas test medium output by the proportional pressure reducing valve is continuously pressurized to the gas storage tank through the booster; The gas test medium is inflated to the standard sample through the gas storage tank, gas flow meter, pressure sensor, and inflatable two-way solenoid valve; the pressure limiting valve of the standard sample is opened, and the gas flow meter detects when the pressure limiting valve of the standard sample is opened. Flow value, and calibrate the opening pressure limit of the pressure limiting valve detected by the pressure sensor; after calibration, the two-way solenoid valve for inflation is closed, the two-way solenoid valve for exhaust is opened, and the gas test medium in the test device is exhausted through the two-way solenoid valve for exhaust ;When the pressure value of the gas test medium detected by the pressure sensor is lower than the lower limit of the opening pressure of the pressure limiting valve, the exhaust two-way solenoid valve is closed; the proportional pressure reducing valve restores the pressure of the gas test medium to the initial pressure value, and the calibration is completed. Remove the standard sample from the test station.

The standard samples include the upper limit standard sample of the opening pressure of the pressure limiting valve and the lower limit standard sample of the opening pressure of the pressure limiting valve; the upper limit standard sample of the opening pressure of the pressure limiting valve and the lower limit standard sample of the opening pressure of the pressure limiting valve are respectively installed in the test station The position of the pressure limiting valve is used to calibrate the upper and lower limits of the opening pressure of the pressure limiting valve of the device.

The pressure limiting valve opening pressure dry test device of the present invention includes a gas source, a pressure regulating valve, a proportional pressure reducing valve, a supercharger, a gas storage tank, a gas flow meter, a pressure sensor, a two-way solenoid valve for inflation, and a two-way solenoid valve for exhaust. Valve, electric control device; gas source, pressure regulating valve, proportional pressure reducing valve, supercharger, gas storage tank, gas flow meter, pressure sensor, inflatable two-way solenoid valve are connected in series in sequence; proportional pressure reducing valve controls increasing The pressure speed ensures the accuracy and repeatability of the detection; the supercharger and the gas storage tank ensure that the test can provide sufficient and increased inflation in an instant; the exhaust two-way solenoid valve is connected between the gas storage tank and the gas flowmeter. On the pipeline; the electronic control device is electrically connected with the gas flow meter, pressure sensor, two-way inflation solenoid valve, and two-way exhaust solenoid valve; in the initial state, the two-way exhaust solenoid valve and the two-way inflation solenoid valve are closed; proportional pressure reduction The valve will stably adjust the pressure of the gas test medium through the pressure regulating valve to the initial pressure value to ensure a stable gas source, which is less than the lower limit of the opening pressure of the pressure limiting valve 0.05MPa; when the test is started, the inflatable two-way solenoid valve is opened, Inflate the pressure limiting valve; when the gas flow meter detects that the gas flow reaches the set flow value, the electronic control device controls the pressure sensor to detect the pressure value of the gas test medium in the pipeline; at the same time, the inflation two-way solenoid valve is closed, and the exhaust two-way The one-way solenoid valve is opened; when the pressure value of the gas test medium detected by the pressure sensor is lower than the initial pressure value, the exhaust two-way solenoid valve is closed, and the proportional pressure reducing valve adjusts the gas source pressure to the initial pressure value; this round of test ends.

The air pressure ratio between the input and output air pressure of the supercharger of the pressure limiting valve opening pressure dry test device of the present invention is greater than or equal to 1:4.

The pressure limiting valve opening pressure dry test device of the present invention also includes a muffler; the muffler is connected with the exhaust two-way electromagnetic valve pipeline, and the noise is reduced when the exhaust two-way electromagnetic valve is opened to exhaust.

The pressure limiting valve opening pressure dry test device of the present invention also includes a standard sample; two standard samples, including a pressure limiting valve opening pressure upper limit standard sample and a pressure limiting valve opening pressure lower limit standard sample, the standard sample is composed of an oil type Test bench calibration.

The positive effects of the present invention are: the opening pressure detection of the pressure limiting valve is accurate and the repetition accuracy is very high; it is very easy to detect the stuck pressure limiting valve or the upper limit pump; the test method is simple, the cost is extremely low, the test period is very short, and the Affect the product cleanliness index, good operating environment and convenient transportation.

Description of drawings

Fig. 1 is a structural representation of the present invention;

In the figure: 1 gas source, 2 pressure regulating valve, 3 proportional pressure reducing valve, 4 supercharger, 5 gas storage tank, 6 gas flow meter, 7 pressure sensor, 8 inflatable two-way solenoid valve, 9 standard sample, 10 Exhaust two-way solenoid valve, 11 muffler, 12 test workpiece pressure limiting valve.

detailed description

Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

The first embodiment of the present invention is shown in Figure 1. The pressure limiting valve opening pressure dry test device includes a gas source 1, a pressure regulating valve 2, a proportional pressure reducing valve 3, a booster 4 with a four-fold boosting ratio, and an air storage tank. 5. Gas flowmeter 6, pressure sensor 7, inflation two-way solenoid valve 8, standard sample 9, exhaust two-way solenoid valve 10, muffler 11, electric control device; two standard samples 9, including pressure limiting valve Opening pressure upper limit standard sample 9 and pressure limiting valve opening pressure lower limit standard sample 9, the standard sample 9 is accurately calibrated by the oil test bench; air source 1, pressure regulating valve 2, proportional pressure reducing valve 3, supercharger 4 , gas storage tank 5, gas flow meter 6, pressure sensor 7, and inflatable two-way solenoid valve 8 are connected in series in sequence; proportional pressure reducing valve 3 controls the speed of boosting to ensure the accuracy and repeatability of detection; quadruple boosting The supercharger 4 and the air storage tank 5 ensure that the test provides enough increased inflation in an instant; the exhaust two-way solenoid valve 10 is connected on the pipeline between the air storage tank 5 and the gas flow meter 6; the muffler 11 is connected to the exhaust two-way solenoid valve 10 pipeline; the electric control device is electrically connected to the gas flow meter 6, the pressure sensor 7, the inflation two-way solenoid valve 8, and the exhaust two-way solenoid valve 10; the initial state, the exhaust two-way Open the solenoid valve 10, close the two-way solenoid valve 8 for inflation, and the proportional pressure reducing valve 3 will stably adjust the air pressure passing through the pressure regulating valve 2 to the initial pressure value to ensure a stable supply of air source, and its value is less than the lower limit of the opening pressure of the pressure limiting valve The value is 0.05MPa; when the test is started, the inflatable two-way solenoid valve 8 is opened, and the air source 1 continues to pump air; the air passing through the pressure regulating valve 2 is accurately regulated at a certain speed ratio through the proportional pressure reducing valve 3; the pressure is reduced by the ratio The air output by the valve 3 is continuously pressurized to the air storage tank 5 through the booster 4 with a four-fold boosting ratio; The pressure limiting valve 12 is inflated; when the gas flow meter 6 detects that the gas flow reaches the set flow value, the electronic control device controls the pressure sensor 7 to detect the air pressure value in the pipeline; at the same time, the inflation two-way solenoid valve 8 is closed, and the exhaust The two-way solenoid valve 10 is opened; when the air pressure value detected by the pressure sensor 7 is lower than the initial pressure value, the exhaust two-way solenoid valve 10 is closed, and the proportional pressure reducing valve 3 adjusts the air source pressure to the initial pressure value, and this round of test ends .

The test method uses air as the medium, and uses the principle of balance between the force of the pressure limiting valve spring and the gas pressure charged into the high pressure chamber of the oil pump; the opening of the pressure limiting valve is judged by the change of the inflated gas volume when the pressure limiting valve body moves to the open position Pressure, the gas volume is detected by the gas flow meter 6 in the inflation pipeline; before the test, the gas-filled two-way solenoid valve 8 is connected to the standard sample 9 pipeline, and the test device is calibrated; during the test, the gas-filled two-way solenoid valve 8 and the The test piece pressure limiting valve 12 is connected to the pipeline.

The specific process is as follows:

The first step, device calibration:

The standard sample 9 includes a pressure limiting valve opening pressure upper limit standard sample 9 and a pressure limiting valve opening pressure lower limit standard sample 9; the pressure limiting valve opening pressure upper limit standard sample 9 and the pressure limiting valve opening pressure lower limit standard sample 9 Installed on the position of the pressure limiting valve 12 of the test work piece in the test station, to respectively calibrate the upper limit and lower limit of the opening pressure of the pressure limiting valve of the device;

Before the test, the exhaust two-way solenoid valve 10 and the inflation two-way solenoid valve 8 were closed; the proportional pressure reducing valve 3 stably adjusted the air pressure passing through the pressure regulating valve 2 to the initial pressure value to ensure a stable air supply, and the value was less than the limit The lower limit of the opening pressure of the pressure valve is 0.05MPa; install the standard sample 9 of the opening pressure of the pressure limiting valve on the position of the pressure limiting valve 12 of the test workpiece at the test station; 1 Continuous pumping of air; the air passing through the pressure regulating valve 2 passes through the proportional pressure reducing valve 3 to precisely adjust the pressure at a certain speed ratio; the air output from the proportional pressure reducing valve 3 passes through the supercharger with a four-fold boosting ratio and stores air in 4 directions The tank 5 is continuously pressurized; the air is inflated to the standard sample 9 through the air storage tank 5, the gas flow meter 6, the pressure sensor 7, and the inflatable two-way solenoid valve 8; the pressure limiting valve of the standard sample 9 is opened, and the standard sample is recorded and set. When the part 9 pressure limiting valve was opened, the gas flow meter 6 detected flow value was the gas flow meter flow set value, so as to calibrate the upper limit and the lower limit of the opening pressure of the pressure limiting valve detected by the pressure sensor 7; the opening pressure of the pressure limiting valve of the test device of the present invention After the upper and lower limits are calibrated, the inflation two-way solenoid valve 8 is closed, the exhaust two-way solenoid valve 10 is opened, and the air in the test device passes through the exhaust two-way solenoid valve 10 and the muffler 11 to reduce noise and exhaust; when the pressure sensor 7 detects When the air pressure value is lower than the initial pressure value, the exhaust two-way solenoid valve 10 is closed; the proportional pressure reducing valve 3 adjusts the air source pressure to the initial pressure value, and after the calibration is completed, the standard sample 9 is removed from the testing station.

The second step is to detect the opening pressure of the pressure limiting valve:

Before the test, the exhaust two-way solenoid valve 10 and the inflation two-way solenoid valve 8 were closed; the proportional pressure reducing valve 3 stably adjusted the air pressure passing through the pressure regulating valve 2 to the initial pressure value to ensure a stable air supply, and the value was less than the limit The lower limit of the opening pressure of the pressure valve is 0.05MPa; at the beginning of the test, the inflatable two-way solenoid valve 8 is opened, and the air source 1 continues to pump air; the air passing through the pressure regulating valve 2 passes through the proportional pressure reducing valve 3 to accurately adjust the pressure at a certain speed ratio , the air output by the proportional decompression valve 3 is continuously pressurized to the air storage tank 5 through the supercharger 4 with a four-fold boosting ratio; The valve 8 inflates the pressure limiting valve 12 of the test workpiece; the gas flow meter 6 detects the air flow; when the air flow detected by the gas flow meter 6 reaches the set flow value, the air pressure value detected by the pressure sensor 7 is the opening pressure of the pressure limiting valve value.

The third step, exhaust and restore the initial:

The inflation two-way solenoid valve 8 is closed, the exhaust two-way solenoid valve 10 is opened, and the air in the test device passes through the exhaust two-way solenoid valve 10 and the muffler 11 to reduce noise and exhaust; when the air pressure value detected by the pressure sensor 7 is lower than the initial When the pressure value is reached, the exhaust two-way solenoid valve 10 is closed; the proportional pressure reducing valve 3 precisely adjusts the air pressure to restore the initial pressure value for the next test; to ensure the repeatability accuracy of the test.

The second embodiment of the present invention is shown in Fig. 1, and the pressure-limiting valve opening pressure dry-type test device automatically seals the oil pump high-pressure chamber communicated with the test workpiece pressure-limiting valve 12, utilizes a supercharger to inflate and pressurize the high-pressure chamber, and the high-pressure air Acting on the plunger or steel ball of the pressure limiting valve, when the pressure of the high pressure air is greater than the spring preload of the pressure limiting valve 12 of the test workpiece, the plunger or steel ball of the pressure limiting valve 12 of the test workpiece will gradually open; The pressure valve 12 is deflated. At this time, when the gas flow meter 6 detects that the gas flow reaches the set flow index, the pressure sensor 7 collects the air pressure value at this time, which is the opening pressure of the pressure limiting valve. This method is convenient and accurate in detection, and the repeatability is also very high.

Claims (8)

1. A dry test method for opening pressure of a pressure limiting valve, characterized in that: comprising: The first step is to detect the opening pressure of the pressure limiting valve: Before the test, the exhaust two-way solenoid valve and the inflation two-way solenoid valve are closed; the proportional pressure reducing valve can stably adjust the pressure of the gas test medium passing through the pressure regulating valve to the initial pressure value to ensure a stable gas supply, and its value is lower than that of the pressure limiting valve The lower limit of the opening pressure; the pressure limiting valve of the test workpiece is sealed with the gas-filled two-way solenoid valve pipeline; when the test is started, the gas-filled two-way solenoid valve is opened, and the gas source is continuously pumped into the gas test medium; Accurate pressure regulation at a certain speed ratio through the proportional pressure reducing valve; the gas test medium output by the proportional pressure reducing valve is continuously pressurized to the gas storage tank through the supercharger; the gas test medium is passed through the gas storage tank, gas flowmeter, pressure sensor, The inflatable two-way solenoid valve inflates the pressure limiting valve of the test workpiece; the gas flowmeter detects the flow rate of the gas test medium; when the gas flowmeter detects that the flow rate of the gas test medium reaches the set flow value, the pressure value of the gas test medium detected by the pressure sensor is the limit value. Pressure valve opening pressure value; The second step, exhaust and restore the initial: The inflatable two-way solenoid valve is closed, the exhaust two-way solenoid valve is opened, and the gas test medium in the test device is exhausted through the exhaust two-way solenoid valve; when the pressure value of the gas test medium detected by the pressure sensor is lower than the initial pressure value, the exhaust The two-way solenoid valve is closed; the proportional pressure reducing valve restores the pressure of the gas test medium to the initial pressure value for the next test; to ensure the repeatability accuracy of the test. 2. A dry test method for opening pressure of a pressure limiting valve according to claim 1, characterized in that: before the test starts, the difference between the pressure value of the gas test medium regulated by the proportional pressure reducing valve and the lower limit of the opening pressure of the pressure limiting valve The difference is greater than or equal to 0.05MPa. 3. A dry test method for opening pressure of a pressure limiting valve according to claim 1, characterized in that: before the detection of the pressure limiting valve of the test workpiece, the pressure limiting valve opening pressure limit calibration of the pressure sensor test is also included; including: Before calibration, the exhaust two-way solenoid valve and the inflation two-way solenoid valve are closed; the proportional pressure reducing valve can stably adjust the pressure of the gas test medium passing through the pressure regulating valve to the initial pressure value to ensure a stable gas source, and its value is lower than that of the pressure limiting valve The lower limit of the opening pressure; connect the standard sample of the opening pressure of the pressure limiting valve to the pipeline of the inflatable two-way solenoid valve; use the opening pressure limit of the pressure limiting valve of the calibration device; During calibration, the inflatable two-way solenoid valve is opened, and the gas source is continuously pumped into the gas test medium; the gas test medium passing through the pressure regulating valve is accurately regulated at a certain speed ratio through the proportional pressure reducing valve; the gas test medium output by the proportional pressure reducing valve The gas storage tank is continuously pressurized through the supercharger; the gas test medium is inflated to the standard sample through the gas storage tank, gas flow meter, pressure sensor, and inflatable two-way solenoid valve; the pressure limiting valve of the standard sample is opened, recorded and set When the pressure limiting valve of the standard sample is opened, the gas flow meter detects the flow value, and calibrates the opening pressure limit of the pressure limiting valve detected by the pressure sensor; After calibration, the inflatable two-way solenoid valve is closed, the exhaust two-way solenoid valve is opened, and the gas test medium in the test device is exhausted through the exhaust two-way solenoid valve; when the pressure value of the gas test medium detected by the pressure sensor is lower than the pressure limit valve, it opens When the pressure is at the lower limit, the exhaust two-way solenoid valve is closed; the proportional pressure reducing valve restores the pressure of the gas test medium to the initial pressure value, and the calibration ends. 4. A dry test method for the opening pressure of a pressure limiting valve according to claim 3, characterized in that: two standard samples of the opening pressure of the pressure limiting valve, including a standard sample of the upper limit of the opening pressure of the pressure limiting valve and a pressure limiting valve The lower limit standard sample of the opening pressure; the upper limit standard sample of the opening pressure of the pressure limiting valve and the lower limit standard sample of the opening pressure of the pressure limiting valve are respectively sealed and connected with the inflatable two-way solenoid valve; respectively calibrate the upper limit and lower limit of the opening pressure of the pressure limiting valve detected by the pressure sensor . 5. A dry-type test device for opening pressure of a pressure limiting valve, characterized in that it includes a gas source, a pressure regulating valve, a proportional pressure reducing valve, a supercharger, an air storage tank, a gas flow meter, a pressure sensor, and an inflatable two-way electromagnetic Valve, exhaust two-way solenoid valve, electric control device; gas source, pressure regulating valve, proportional pressure reducing valve, supercharger, gas storage tank, gas flow meter, pressure sensor, and inflation two-way solenoid valve are connected in series in sequence ; The exhaust two-way solenoid valve is connected to the pipeline between the gas storage tank and the gas flowmeter; the electric control device is electrically connected to the gas flowmeter, pressure sensor, inflation two-way solenoid valve, and exhaust two-way solenoid valve; state, the exhaust two-way solenoid valve and the inflation two-way solenoid valve are closed; the proportional pressure reducing valve can stably adjust the pressure of the gas test medium passing through the pressure regulating valve to the initial pressure value to ensure a stable gas supply, and its value is less than that of the pressure limiting valve. The lower limit of pressure is 0.05MPa; when the test starts, the inflatable two-way solenoid valve opens to inflate the pressure limiting valve; when the gas flow meter detects that the gas flow reaches the set flow value, the electronic control device controls the pressure sensor to detect the pressure in the pipeline. At the same time, the inflatable two-way solenoid valve is closed, and the exhaust two-way solenoid valve is opened; when the pressure value of the gas test medium detected by the pressure sensor is lower than the initial pressure value, the exhaust two-way solenoid valve is closed, and the proportional reduction The pressure valve adjusts the air source pressure to the initial pressure value. 6. A dry-type test device for opening pressure of a pressure limiting valve according to claim 5; characterized in that the ratio of the input and output air pressure of the supercharger is greater than or equal to 1:4. 7. A pressure-limiting valve cracking pressure dry test device according to claim 5; characterized in that: it also includes a muffler; the muffler is connected to the exhaust two-way solenoid valve pipeline. 8. A dry test device for the opening pressure of a pressure limiting valve according to claim 5; it is characterized in that: it also includes a standard sample; two standard samples, including a standard sample of the upper limit of the opening pressure of the pressure limiting valve and a pressure limiting The standard sample of the lower limit of the valve opening pressure, which is calibrated by the oil test bench.