Overpressure prevention type differential pressure valve, high static pressure differential pressure detection device and application thereof

Abstract

The application belongs to the technical field of hydraulic system detection, and discloses an overpressure prevention type differential pressure valve, a high static pressure differential pressure detection device and application of the overpressure prevention type differential pressure valve. The overpressure prevention type differential pressure valve comprises a valve body, an installation cavity and a differential pressure oil cavity which are connected from top to bottom in the valve body; a valve rod is arranged in the valve body from top to bottom, and the lower end of the valve rod is limited in the differential pressure oil cavity, and an elastic element and a limiting assembly are further arranged on the valve rod; the elastic element is compressed between the upper end of the installation cavity and the limiting assembly; a differential pressure plate is installed in the differential pressure oil cavity, a first oil inlet and outlet and a second oil inlet and outlet are arranged on the differential pressure oil cavity, the valve rod can drive the differential pressure plate to slide up and down between the two oil inlets and outlets to compress the oil volume and form a differential pressure; when the differential pressure plate moves downward, the oil below the differential pressure plate can generate a reaction force on the valve rod, when the pre-pressing force of the elastic element is greater than the reaction force, the limiting assembly can abut against the lower end surface of the installation cavity, otherwise, the limiting assembly is separated from the installation cavity. The application can realize adjustable control of the maximum value of high static pressure differential pressure and prevent differential pressure overload.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of hydraulic system detection, and more particularly to an overpressure prevention type differential pressure valve, a high static pressure differential pressure detection device and application thereof. BACKGROUND

[0002] At present, oil, water, gas and other oil liquids are widely used in various fields of social production and life. In the process of fluid flow, a certain differential pressure will be generated under the influence of resistance. Differential pressure is one of the key parameters for judging whether the fluid equipment is running normally. The calibration and verification process of differential pressure instruments such as differential pressure gauge and differential pressure sensor, as key instruments for detecting differential pressure, needs to be strictly controlled.

[0003] Generally speaking, the verification device of differential pressure instrument usually works under low static pressure condition, that is, the high pressure end of differential pressure instrument is connected to the verification test device, and the low pressure end is directly connected to the atmosphere. When the static pressure is atmospheric pressure, the performance of differential pressure instrument is verified. However, in practice, differential pressure instrument often works under high static pressure of tens of megapascals. The pressure of differential pressure verification test device is realized by compressing oil volume. Under high static pressure, it is difficult to adjust the trace differential pressure. Excessive static pressure will cause excessive deformation of the strain unit of differential pressure instrument, affect the detection accuracy, and easily cause the damage of the differential pressure instrument under test due to differential pressure overload. In view of this situation, it is necessary to propose an overpressure prevention type differential pressure verification test device under high static pressure to realize the differential pressure instrument detection under high static pressure environment. SUMMARY

[0004] In view of the defects of the prior art, the purpose of the present application is to provide an overpressure prevention type differential pressure valve, a high static pressure differential pressure detection device and application thereof, so as to solve the problem that the existing differential pressure detection device is easy to cause differential pressure overload when detecting differential pressure under high static pressure environment.

[0005] To achieve the above purpose, the present application provides an overpressure prevention type differential pressure valve, which comprises a valve body, an installation cavity and a differential pressure oil cavity which are communicated from top to bottom in the valve body; a valve rod is arranged in the valve body from top to bottom, and the lower end of the valve rod is limited in the differential pressure oil cavity, and an elastic member and a limiting assembly are further sleeved on the upper end of the valve rod; the elastic member is compressed between the upper end of the installation cavity and the limiting assembly; a differential pressure plate is installed in the differential pressure oil cavity, the upper end of the differential pressure oil cavity is provided with a first oil inlet and outlet, and the lower end of the differential pressure oil cavity is provided with a second oil inlet and outlet, the valve rod can drive the differential pressure plate to slide up and down between the first oil inlet and outlet and the second oil inlet and outlet to compress the oil volume and form differential pressure; when the differential pressure plate moves downward, the oil below the differential pressure plate can generate a reaction force on the valve rod, and when the pre-pressing force of the elastic member is greater than the reaction force, the limiting assembly can abut against the lower end surface of the installation cavity, otherwise the limiting assembly is separated.

[0006] Further, the limiting assembly comprises a limiting structure and a movable sleeve, which are sequentially sleeved on the valve rod from top to bottom, the lower part of the movable sleeve is connected with the valve rod, and the upper part of the movable sleeve is provided with a height adjusting groove; the limiting structure is located inside the height adjusting groove, and when the two opposite surfaces abut against each other, the elastic member is compressed to the shortest.

[0007] Further, the bottom of the mounting cavity is provided with a valve rod limiting piece, the lower end of the valve rod is provided with a boss, and the upper end surface of the boss abuts against the lower end surface of the valve rod limiting piece, so that the boss is limited in the differential pressure oil cavity.

[0008] Further, the upper end of the valve body is further provided with an adjusting cap, the adjusting cap is used for adjusting the pre-compression height of the elastic member, and the elastic member is limited in the mounting cavity.

[0009] Further, the lower end of the valve rod is semispherical, and the diameter of the semispherical shape is greater than the diameter of the valve body of the valve rod.

[0010] Further, the limiting assembly is externally provided with a stop boss, and the lower end surface of the elastic member abuts against the stop boss.

[0011] Further, the first inlet and outlet port is an inclined port, and the inclined port is in a state of high inside and low outside; the second inlet and outlet port is a horizontal port, and the horizontal port is located at the same horizontal plane as the bottom of the differential pressure oil cavity.

[0012] According to another aspect of the present application, a high static pressure overpressure prevention type differential pressure detection device is also disclosed, the detection device is provided with the overpressure prevention type differential pressure valve according to any one of the preceding aspects, the detection device further comprises a hydraulic pump, and a first needle valve arranged at the output end of the hydraulic pump; the first needle valve is connected with a second needle valve, a differential pressure valve and an input end of a calibrated differential pressure instrument through a low pressure pipeline respectively; the output ends of the second needle valve, the differential pressure valve and the calibrated differential pressure instrument are connected through a high pressure pipeline; when the first needle valve and the second needle valve are closed, the hydraulic pump, the low pressure pipeline and the high pressure pipeline are disconnected, the low pressure pipeline and the high pressure pipeline maintain corresponding static pressures, the differential pressure valve can adjust the differential pressure between the low pressure pipeline and the high pressure pipeline to prevent overpressure.

[0013] Further, a first valve is arranged between the input end of the differential pressure valve and the input end of the calibrated differential pressure instrument, which is used for on-off of the low pressure pipeline; a second valve is arranged between the output end of the differential pressure valve and the output end of the calibrated differential pressure instrument, which is used for on-off of the high pressure pipeline.

[0014] According to still another aspect of the present application, an application method of a high static pressure overpressure prevention type differential pressure detection device is also disclosed, the application method comprises the following steps:

[0015] The output end and the input end of the to-be-tested differential pressure instrument are respectively connected with two ends of the calibration differential pressure instrument correspondingly;

[0016] The first needle valve and the second needle valve are opened, and the hydraulic pump is controlled, so that the static pressure of the detection device is the preset pressure;

[0017] The differential pressure valve is adjusted, so that the pressure of the high-pressure pipeline is increased, and the pressure of the low-pressure pipeline is decreased, until the differential pressure between the to-be-tested differential pressure instrument and the calibration differential pressure instrument is increased to the target differential pressure;

[0018] The readings of the calibration differential pressure instrument and the to-be-tested differential pressure instrument are compared, so as to determine the precision of the to-be-tested differential pressure instrument.

[0019] Compared with the prior art, the above technical scheme of the present application mainly has the following advantages:

[0020] 1. The overpressure prevention type differential pressure valve of the present application sets a differential pressure plate in the differential pressure oil cavity to separate the first inlet and outlet oil port from the second inlet and outlet oil port; when the valve rod moves downward under external force, the differential pressure plate can move downward to extrude the oil below, and the differential pressure plate generates a reaction force to the valve rod under the pressure of the oil below, and the reaction force is transmitted to the elastic member sleeved on the valve rod, when the pre-pressing force of the elastic member is greater than the reaction force, the limiting assembly can abut against the lower end surface of the mounting cavity, otherwise it will be separated, when it is separated, the limiting assembly will move upward, and the valve rod will not continue to move downward and upward due to force balance, that is, the high and low pressure end differential pressure of the overpressure prevention type differential pressure valve is basically constant, thereby realizing the differential pressure regulation of preventing overpressure.

[0021] 2. The differential pressure valve of the present application adjusts the pre-compression height of the limiting assembly by setting an external adjusting cap, thereby realizing the effect of pre-adjusting the maximum value of the differential pressure of the differential pressure valve, and being able to flexibly cope with various high static pressure situations.

[0022] 3. The limiting assembly of the overpressure prevention type differential pressure valve in the present application includes a limiting structure and a movable sleeve which are sequentially sleeved on the valve rod from top to bottom, the upper part of the movable sleeve is provided with a height adjusting groove, the limiting structure is located inside the height adjusting groove, and the movable sleeve can move up and down relative to the limiting structure, when the lower end surface of the limiting structure abuts against the bottom surface of the height adjusting groove, the elastic member can be compressed to the shortest, and when the lower end surface of the movable sleeve abuts against the lower end surface of the mounting cavity, the movable sleeve is still connected with the limiting structure, so that the movable sleeve will not be separated.

[0023] 4. The high static pressure overpressure prevention type differential pressure detection device provided by the present application adjusts the differential pressure between the low pressure pipeline and the high pressure pipeline by setting an overpressure prevention type differential pressure valve therebetween; when the differential pressure value between the two ends of the differential pressure valve reaches the differential pressure limit value, the limiting assembly and the lower end of the installation cavity are separated under the oil reaction force, the valve rod continues to rotate, the limiting assembly moves upward relative to the valve rod, the valve rod remains in place due to force balance, and the differential pressure plate no longer moves downward due to the loss of external force, thereby avoiding further extrusion of the oil and causing the differential pressure between the high pressure pipeline and the low pressure pipeline to be overloaded; after the differential pressure adjustment is completed, the static pressure at the two ends of the differential pressure instrument can reach about 10 MPa, and the differential pressure can slowly rise to the target differential pressure, thereby determining the indication between the to-be-measured instrument and the calibrated differential pressure instrument, and achieving the effect of accurately determining the precision of the to-be-measured instrument. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is the structure diagram of the overpressure prevention type differential pressure valve provided by the embodiment of the present application;

[0025] Figure 2 is the structure diagram of the overpressure prevention type differential pressure valve after forming the differential pressure provided by the embodiment of the present application;

[0026] Figure 3 is the structure diagram of the high static pressure overpressure prevention type differential pressure detection test device provided by the embodiment of the present application.

[0027] In the figure: 1 - hydraulic pump, 2 - first needle valve, 3 - low pressure pipeline, 4 - first valve, 5 - second needle valve, 6 - differential pressure valve, 6.1 - valve body, 6.11 - first oil inlet and outlet, 6.12 - second oil inlet and outlet, 6.2 - differential pressure plate, 6.3 - valve rod, 6.31 - boss, 6.4 - adjusting cap, 6.5 - elastic member, 6.6 - limiting structure, 6.7 - movable sleeve, 6.71 - height adjusting groove, 6.8 - valve rod limiting member, 6.9 - sealing member, 7 - high pressure pipeline, 8 - second valve, 9 - calibrated differential pressure instrument, 10 - to-be-measured differential pressure instrument. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present application clearer and more apparent, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0029] In the description of the present application, it is to be understood by the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0030] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified and limited.

[0031] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] Embodiment 1

[0033] To achieve the above-mentioned purpose, the present embodiment provides an overpressure prevention type differential pressure valve, which comprises Figure 1 and 2As shown, the differential pressure valve 6 comprises a valve body 6.1, which is internally provided with an installation cavity and a differential pressure oil cavity communicated from top to bottom, and the inner diameter of the installation cavity is larger than that of the differential pressure oil cavity; a valve rod 6.3 is provided in the valve body from top to bottom, and the lower end thereof is limited in the differential pressure oil cavity, and the upper part thereof is located in the installation cavity, and the upper part thereof is further sleeved with an elastic element 6.5 and a limiting assembly; the elastic element 6.5 is compressed between the upper end of the installation cavity and the limiting assembly; a differential pressure plate 6.2 is installed in the differential pressure oil cavity, the upper end of the differential pressure oil cavity is provided with a first oil inlet and outlet 6.11, and the lower end thereof is provided with a second oil inlet and outlet 6.12, and the differential pressure plate 6.2 separates the first oil inlet and outlet 6.11 from the second oil inlet and outlet 6.12; the valve rod 6.3 can drive the differential pressure plate 6.2 to slide up and down between the first oil inlet and outlet 6.11 and the second oil inlet and outlet 6.12 to compress the oil volume and form a differential pressure; when the differential pressure plate 6.2 moves downward, the oil below the differential pressure plate 6.2 can generate a reaction force on the valve rod 6.3, and when the pre-compression force of the elastic element 6.5 is greater than the reaction force, the limiting assembly can tightly abut against the lower end surface of the installation cavity, and vice versa, when the pre-compression force is greater than the reaction force, the differential pressure limit value is reached, and at this time, the limiting assembly and the lower end surface of the installation cavity can be separated.

[0034] Specifically, the limiting assembly and the valve rod can be connected through threads, when the differential pressure value of the differential pressure valve reaches the differential pressure limit value (i.e. when the differential pressure will be overloaded), continue to rotate the valve rod 6.3 clockwise to make it downward, the valve rod 6.3 remains unchanged in position under the balance of forces, and the limiting assembly can move upward under the transmission of threads, at this time, the differential pressure plate 6.2 will not be driven downward, so it cannot continue to move downward to compress the oil, thereby avoiding differential pressure overload.

[0035] In the preferred embodiment, the limiting assembly comprises a limiting structure 6.6 and a movable sleeve 6.7 which are sequentially sleeved on the valve rod 6.3 from top to bottom, the lower part of the movable sleeve 6.7 is connected with the valve rod 6.3, and the upper part thereof is provided with a height adjusting groove 6.71, and the limiting structure 6.6 is located inside the height adjusting groove 6.71, when the end surfaces of the two abut against each other, the elastic element 6.5 is compressed to the shortest, and the shortest height of the elastic element 6.5 refers to the shortest height that the elastic element 6.5 can reach after being compressed between the movable sleeve 6.7 and the upper end of the installation cavity, which can be artificially determined in advance, and is related to the distance between the movable sleeve 6.7 and the upper end of the installation cavity; specifically, the limiting structure 6.6 is fixed at the middle position of the valve rod, and the inner middle position of the movable sleeve 6.7 is connected with the valve rod 6.3, and the specific connection mode can be threaded connection.

[0036] In the preferred embodiment, the bottom of the installation cavity is provided with a valve rod limiting piece 6.8, the lower end of the valve rod 6.3 is provided with a boss 6.31, and the upper end face of the boss 6.31 abuts against the lower end face of the valve rod limiting piece 6.8 to limit the boss 6.31 in the differential pressure oil cavity; specifically, the valve rod limiting piece 6.8 is a cap-shaped base, a circular hole is formed in the middle of the cap-shaped base for the valve rod 6.3 to pass through, the outer side face is provided with threads, and the inner side face of the installation cavity is also provided with corresponding threads, the two are fixed by thread connection, and sealing structures such as sealing pads or sealing rings are arranged between the valve rod limiting piece 6.8 and the bottom face of the installation cavity and the valve rod 6.3 to achieve sealed connection; the lower end face of the limiting assembly can be attached to the inner bottom face of the cap-shaped base.

[0037] In the preferred embodiment, the upper end of the valve body 6.1 is also provided with an adjusting cap 6.4, which is used to adjust the pre-compression height of the elastic member 6.5 and limit the elastic member 6.5 in the installation cavity; specifically, the inner side wall of the adjusting cap 6.4 is provided with threads, the outer side face of the upper end of the valve body 6.1 is provided with corresponding threads, and the adjusting cap 6.4 is connected with the valve body 6.1 by threads; a circular hole is formed in the middle of the adjusting cap 6.4 for the screw rod to pass through, and the upper end of the elastic member 6.5 abuts against the end face of the adjusting cap 6.4 around the circular hole.

[0038] In a more preferred embodiment, the adjusting cap 6.4 is internally provided with an annular groove, so that the end face of the adjusting cap 6.4 is double-ring-shaped; one side of the annular groove close to the central axis of the adjusting cap 6.4 is provided with internal threads, and the inner side face of the valve body 6.1 is provided with threads that can cooperate with the internal threads, the valve body 6.1 is inserted into the annular groove, and the two are fixed by thread connection, the center bottom face of the adjusting cap 6.4 can adjust the height and limit the elastic member 6.5 by adjusting the screwing position of the two; when the height of the adjusting cap 6.4 is adjusted, the elastic member does not contact the inner wall of the annular groove, so it does not interfere with the elastic member 6.5.

[0039] In the preferred embodiment, the lower end of the valve rod 6.3 is hemispherical, and the diameter of the hemisphere is larger than the diameter of the valve body of the valve rod 6.3, so that the lower end of the valve rod 6.3 can be limited in the differential pressure oil cavity and will not come out of the differential pressure oil cavity when moving upward.

[0040] In the preferred embodiment, the first inlet and outlet port 6.11 is an inclined port, and the inclined port is in a high inside and low outside state to avoid external oil easily entering the differential pressure oil cavity; the second inlet and outlet port is a horizontal port, and the horizontal port is located at the same horizontal plane as the bottom of the differential pressure oil cavity, so that the differential pressure plate 6.2 can easily squeeze out the lower oil.

[0041] The aforementioned elastic element 6.5 can be a spring. Sealing structures are provided at the locations that require sealing, such as between the aforementioned valve stem limiting element 6.8 and the valve stem 6.3, between the valve stem limiting element 6.8 and the lower end face of the mounting cavity, and between the differential pressure plate 6.2 and the side wall of the differential pressure oil cavity. The sealing structures can be gaskets, sealing rings, etc.

[0042] Example 2

[0043] In this embodiment, as Figure 3 As shown, a high static pressure overpressure prevention differential pressure detection device is disclosed. The detection device is equipped with an overpressure prevention differential pressure valve as disclosed in any of the preceding embodiments. The detection device also includes a hydraulic pump 1 and a first needle valve 2 disposed at the output end of the hydraulic pump 1. Specifically, the two are connected by a pipeline. The first needle valve 2 is connected to the input end of the second needle valve 5, the differential pressure valve 6, and the calibration differential pressure instrument 9 through a low-pressure pipeline 3. The output ends of the second needle valve 5, the differential pressure valve 6, and the calibration differential pressure instrument 9 are all connected by a high-pressure pipeline 7. When the first needle valve 2 and the second needle valve 5 are closed, the hydraulic pump 1, the low-pressure pipeline 3, and the high-pressure pipeline 7 are disconnected, and the low-pressure pipeline 3 and the high-pressure pipeline 7 maintain the corresponding static pressure. The differential pressure valve 6 can adjust the differential pressure between the low-pressure pipeline 3 and the high-pressure pipeline 7 to prevent overpressure.

[0044] A first valve 4 is also provided between the input end of the differential pressure valve 6 and the input end of the calibration differential pressure instrument 9, which is used to switch the low-pressure pipeline 3 on and off to achieve rapid pressure relief after detection; a second valve 8 is also provided between the output end of the differential pressure valve 6 and the output end of the calibration differential pressure instrument 9, which is used to switch the high-pressure pipeline 7 on and off to achieve rapid pressure relief after detection.

[0045] Example 3

[0046] This embodiment provides an application method for any of the above-mentioned high static pressure overpressure prevention differential pressure detection devices, specifically including the following steps:

[0047] Connect the output and input terminals of the differential pressure instrument 10 to the corresponding terminals of the differential pressure instrument 9 for calibration.

[0048] Open the first needle valve 2 and the second needle valve 5, and adjust the hydraulic pump 1 to make the static pressure of the detection device reach the preset pressure. Specifically, when both the first needle valve 2 and the second needle valve 5 are open, the hydraulic pump 1, the low-pressure line 3 and the high-pressure line 7 are connected, and the pressure of the three is the same. At this time, the static pressure of the low-pressure line 3 and the high-pressure line 7 can be adjusted by the hydraulic pump 1. When the two needle valves are closed, the hydraulic pump 1, the low-pressure line 3 and the high-pressure line 7 are isolated, and the pressure of the three is independent. The low-pressure line 3 and the high-pressure line 7 maintain a certain static pressure. At this time, the differential pressure between the low-pressure line 3 and the high-pressure line 7 can be adjusted by the overpressure prevention differential pressure valve 6.

[0049] Adjust the differential pressure valve 6 to increase the pressure in the high-pressure line 7 and decrease the pressure in the low-pressure line 3 until the differential pressure between the differential pressure instrument 10 to be measured and the differential pressure instrument 9 to be calibrated rises to the target differential pressure. Specifically, adjust the height of the adjusting cap 6.4 in the differential pressure valve 6 relative to the valve body 6.1 to adjust the pre-compression height of the elastic element 6.5, thereby determining the differential pressure limit.

[0050] Specifically, the adjustment principle of differential pressure valve 6 in this embodiment is as follows:

[0051] Rotating the valve stem 6.3 downwards drives the differential pressure plate 6.2 to slide downwards between the first inlet / outlet port 6.11 and the second inlet / outlet port 6.12 to compress the oil volume and create a differential pressure. When the differential pressure value of the differential pressure valve reaches the differential pressure limit (i.e., when the differential pressure is about to overload), the limiting component will disengage from the lower end face of the mounting cavity under the reaction force of the oil. At this time, if the valve stem 6.3 is rotated in the previous direction, the valve stem 6.3 will remain in its original position, while the limiting component will move upwards relative to the valve stem 6.3. At this time, the differential pressure plate 6.2 is no longer subject to external force and will not be able to continue to move downwards to compress the oil. At this time, the differential pressure at the high and low pressure ends of the anti-differential pressure valve is basically constant, thereby avoiding differential pressure overload.

[0052] Finally, the readings of the calibrated differential pressure gauge 9 and the differential pressure gauge under test 10 are compared to determine the accuracy of the differential pressure gauge under test 10.

[0053] Example 4

[0054] This embodiment provides a detection method for a high static pressure overpressure prevention differential pressure detection device, the specific steps of which include:

[0055] During the test preparation phase, open the first needle valve 2 and the second needle valve 5, adjust the hydraulic pump 1, control the static pressure of the system to the test static pressure of 10MPa, and then close the two needle valves. At this time, the static pressure of both the high pressure line and the low pressure line is 10MPa. The static pressure at both ends of the differential pressure gauge 9 and the differential pressure gauge 10 under test is 10MPa, and the differential pressure is 0MPa.

[0056] At the beginning of the test, the overpressure prevention differential pressure valve 6 was adjusted to increase the pressure in the high-pressure line and decrease the pressure in the low-pressure line. The static pressure at both ends of the calibrated differential pressure instrument 9 and the differential pressure instrument under test 10 was approximately 10 MPa. The differential pressure slowly increased to the target differential pressure. The readings of the calibrated differential pressure instrument 9 and the differential pressure instrument under test 10 were compared to determine the accuracy of the differential pressure instrument under test 10.

[0057] After the test is completed, open the two needle valves and hydraulic pump 1 to release the pressure, thus completing the low pressure difference test under high static pressure.

[0058] To better illustrate the implementation details of the present invention, the following embodiments are provided to further illustrate the present invention. It should be understood that the following embodiments are only preferred implementation methods and are not intended to limit the scope of protection of the present invention in any way.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An overpressure prevention differential pressure valve, characterized in that, The system includes a valve body (6.1), which has a mounting cavity and a differential pressure oil cavity that communicate from top to bottom. A valve stem (6.3) is inserted into the valve body (6.1) from top to bottom, and its lower end is limited in the differential pressure oil cavity. An elastic element (6.5) and a limiting component are also sleeved on its upper part. The elastic element (6.5) is compressed between the upper end of the mounting cavity and the limiting component. A differential pressure plate (6.2) is installed in the differential pressure oil cavity. The upper end of the differential pressure oil cavity has a first inlet / outlet port (6.11), and its lower end has a second inlet / outlet port (6.12). The valve stem (6.3) can drive the differential pressure plate (6.2) to slide up and down between the first inlet / outlet port (6.11) and the second inlet / outlet port (6.12). The differential pressure plate (6.2) moves downward to compress the oil volume, forming a differential pressure. When the differential pressure plate (6.2) moves downward, the oil below it can generate a reaction force on the valve stem (6.3). When the pre-tightening force of the elastic element (6.5) is greater than the reaction force, the limiting component can abut against the lower end face of the mounting cavity; otherwise, it will disengage. The limiting component and the valve stem (6.3) are connected by threads. When the differential pressure value of the differential pressure valve reaches the differential pressure limit, the valve stem (6.3) is rotated clockwise to make it move downward. The valve stem (6.3) is kept in a fixed position by the balanced force from the top and bottom. The limiting component moves upward in the opposite direction under the transmission of the threads, so that the differential pressure plate (6.2) will not be driven downward and cannot continue to move downward to compress the oil, thereby avoiding differential pressure overload.

2. The overpressure prevention differential pressure valve as described in claim 1, characterized in that, The limiting assembly includes a limiting structure (6.6) and a movable sleeve (6.7) sequentially sleeved on the valve stem (6.3) from top to bottom. The lower part of the movable sleeve (6.7) is connected to the valve stem (6.3), and the upper part is provided with a height adjustment groove (6.71). The limiting structure is located inside the height adjustment groove (6.71). When the two surfaces abut against each other, the elastic element (6.5) is compressed to its shortest length.

3. The overpressure prevention differential pressure valve as described in claim 1, characterized in that, A valve stem limiting member (6.8) is provided at the bottom of the mounting cavity, and a boss (6.31) is provided at the lower end of the valve stem (6.3). The upper surface of the boss abuts against the lower surface of the valve stem limiting member (6.8) to limit the boss (6.31) in the differential pressure oil cavity.

4. The overpressure prevention differential pressure valve as described in claim 1, characterized in that, The valve body (6.1) is also provided with an adjusting cap (6.4) at its upper end. The adjusting cap (6.4) is used to adjust the pre-compression height of the elastic element (6.5) and limit the elastic element (6.5) in the mounting cavity.

5. The overpressure prevention differential pressure valve as described in claim 1, characterized in that, The lower end of the valve stem (6.3) is hemispherical, and the diameter of the hemispherical shape is larger than the valve body diameter of the valve stem (6.3).

6. The overpressure prevention differential pressure valve as described in claim 1, characterized in that, The limiting component is provided with a stop protrusion on its exterior, and the lower end face of the elastic element abuts against the stop protrusion.

7. The overpressure prevention differential pressure valve as described in claim 1, characterized in that, The first oil inlet / outlet (6.11) is an inclined port, and the inclined port is in a state of being higher inside and lower outside; the second oil inlet / outlet is a horizontal port, and the horizontal port is located on the same horizontal plane as the bottom of the differential pressure oil chamber.

8. A high static pressure overpressure prevention differential pressure detection device, characterized in that, The detection device is equipped with an overpressure prevention differential pressure valve as described in any one of claims 1-7. The detection device also includes a hydraulic pump (1) and a first needle valve (2) disposed at the output end of the hydraulic pump (1). The first needle valve (2) is connected to the input ends of the second needle valve (5), the overpressure prevention differential pressure valve (6), and the calibration differential pressure instrument (9) respectively through a low-pressure pipeline (3). The output ends of the second needle valve (5), the overpressure prevention differential pressure valve (6), and the calibration differential pressure instrument (9) are all connected through a high-pressure pipeline (7). When the first needle valve (2) and the second needle valve (5) are closed, the hydraulic pump (1), the low-pressure pipeline (3), and the high-pressure pipeline (7) can be disconnected, and the low-pressure pipeline (3) and the high-pressure pipeline (7) maintain corresponding static pressure. The overpressure prevention differential pressure valve (6) can adjust the differential pressure between the low-pressure pipeline (3) and the high-pressure pipeline (7) to avoid overpressure.

9. A high static pressure overpressure prevention differential pressure detection device as described in claim 8, characterized in that, A first valve (4) is provided between the input end of the overpressure prevention type differential pressure valve (6) and the input end of the calibration differential pressure instrument (9) for switching on and off the low-pressure pipeline (3); a second valve (8) is provided between the output end of the overpressure prevention type differential pressure valve (6) and the output end of the calibration differential pressure instrument (9) for switching on and off the high-pressure pipeline (7).

10. The application method of the high static pressure overpressure prevention differential pressure detection device as described in any one of claims 8-9, characterized in that, The application method includes the following steps: Connect the output and input terminals of the differential pressure instrument (10) to the corresponding terminals of the differential pressure instrument (9) for calibration. Open the first needle valve (2) and the second needle valve (5), and adjust the hydraulic pump (1) to make the static pressure of the detection device the preset pressure; Adjust the overpressure prevention differential pressure valve (6) to increase the pressure in the high-pressure line (7) and decrease the pressure in the low-pressure line (3) until the differential pressure between the differential pressure instrument to be measured (10) and the differential pressure instrument to be calibrated (9) rises to the target differential pressure. The readings of the calibrated differential pressure instrument (9) and the differential pressure instrument under test (10) are compared to determine the accuracy of the differential pressure instrument under test (10).

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