A pressure detection auxiliary device for water pressure test

Abstract

The present invention provides a pressure detection auxiliary device for water pressure test, which belongs to the field of valve water pressure test technology. It is used to solve the problem that it is cumbersome to repeatedly replace pressure gauges of different levels during water pressure test, which is easy to cause damage to the device. The present invention includes a cavity, a pressure measuring piston and N groups of pressure gauge groups. A variable-section piston cavity and a stepped variable-section spring cavity are arranged in the cavity. The variable-section piston cavity includes a main control ring cavity and N groups of ring cavities. The main control ring cavity is connected to the main control pipe. Each group of ring cavities is connected to the ring cavity interface pipe, a group of pressure gauge groups and a pressure relief pipe in turn. The pressure gauge group ranges are arranged in sequence. The variable-section spring cavity is built with N-1 annular spring baffles and N springs. The pressure measuring piston is provided with a number of pressure-bearing shoulders, and the ring cavity is between two adjacent pressure-bearing shoulders and the variable-section piston cavity. The present invention does not require repeated replacement of the pressure gauge, can automatically detect the pressure, and can also avoid damage to the detection device.

Description

Technical Field

[0001] The present invention relates to the technical field of valve water pressure testing, and in particular to a pressure detection auxiliary device for water pressure testing. Background Art

[0002] The valve water pressure test is suitable for the pressure resistance and bursting performance test of various automobile hoses, rubber hoses, air conditioning pipes, automobile assemblies, valves and other products. It can measure the bursting pressure and pressure resistance time of various types of pipe fittings. It is widely used in the production, development and research of hoses in various fields such as quality inspection units, automobile parts manufacturing units, product quality inspection stations, scientific research institutions, etc. When the valve product is subjected to water pressure, according to the standard, two pressure gauges of the same specification need to be used, and according to the different water pressure test pressures, the pressure gauge with the appropriate range needs to be selected. When selecting a pressure gauge, the appropriate range is slightly different, usually between 1 / 3-2 / 3 of the pressure gauge range. According to the requirements of NB / T47044, the "Industry Standard of the People's Republic of China - Power Station Valves", the selected pressure gauge range should be 1.5-3 times the test pressure value. For example: PN64 (nominal pressure 6.4MPa) valves need to undergo 7.04MPa water pressure sealing test and 9.6MPa water pressure strength test respectively. According to the standard, the most suitable pressure gauge range is 16MPa pressure gauge. PN100 (nominal pressure 10MPa) valves need to undergo 11MPa water pressure sealing test and 15MPa water pressure strength test respectively. According to the standard, a pressure gauge with a pressure gauge range of 25MPa should be selected.

[0003] When measuring pressure, the existing water pressure test device needs to prepare pressure gauges of different ranges in advance according to different water pressures. If the estimated range is too small, the pressure gauge is easily damaged during the pressure measurement process. If the estimated range is too large, the pressure gauge pointer offset range is small and the pressure value cannot be accurately read. In addition, the pressure gauge needs to be replaced continuously during the test process, which is cumbersome to operate, affects the test efficiency, and brings inconvenience to the operators. Repeated replacement of the pressure gauge is also likely to damage the detection device and reduce its service life. Summary of the invention

[0004] The technical problems to be solved by the present invention are:

[0005] The water pressure test device in the prior art needs to prepare pressure gauges with appropriate ranges according to valves of different pressure levels before the test. The pressure gauges need to be replaced repeatedly during the operation, which is cumbersome and brings inconvenience to the operators. The repeated replacement of the pressure gauges wastes time and easily causes damage to the detection device.

[0006] The present invention adopts the following technical solutions to solve the above technical problems:

[0007] The present invention provides a pressure detection auxiliary device for water pressure test, comprising a cavity, a pressure measuring piston and N groups of pressure gauge groups, wherein N≥3, and N is an integer, a first end cover and a second end cover are respectively arranged at both ends of the cavity, a variable cross-section piston cavity and a stepped variable cross-section spring cavity which are interconnected are arranged in the cavity, a limited position boss is arranged between the variable cross-section piston cavity and the stepped variable cross-section spring cavity, the variable cross-section piston cavity comprises a main control ring cavity and N groups of ring cavities, the number of the pressure gauge group and the ring cavity is the same, the main control ring cavity is between the first end cover, the pressure measuring piston and the variable cross-section piston cavity, the main control ring cavity is connected to the main control pipe, and each group of ring cavities is arranged according to the embodiment of the present invention. It is connected to the annular cavity interface tube, a group of pressure gauge groups and a pressure relief pipe, the pressure gauge group ranges are arranged continuously in sequence, the pressure measuring piston is built into the variable-section piston cavity, the variable-section spring cavity is equipped with N-1 annular spring baffles and N springs, the number of the springs is the same as the number of the pressure gauge groups, the annular spring baffle is one less than the number of the pressure gauge groups, the pressure output end of the pressure measuring piston is connected to one end of the adjacent spring, the other end of the spring is connected to the second end cover, one end of the other springs is connected to the annular spring baffle, and the other end is connected to the second end cover, the springs pass through the next level springs in sequence, and the pressure measuring piston is provided with a plurality of pressure-bearing shoulders.

[0008] Optionally, the annular cavity includes a water-filled ring cavity, a pressure measuring ring cavity and a pressure relief ring cavity, the diameters of the water-filled ring cavity, the pressure measuring ring cavity and the pressure relief ring cavity are larger than the diameter of the pressure measuring piston, the water-filled ring cavity is connected to the ring cavity interface tube, the pressure measuring ring cavity is connected to a group of pressure gauges, and the pressure relief ring cavity is connected to the pressure relief pipe.

[0009] Optionally, the trapezoidal variable-section spring cavity is configured as a truncated cone cavity with successively increasing diameters, a spring is disposed in the truncated cone cavity with the smallest diameter, and annular spring baffles and springs are disposed in the other truncated cone cavities, wherein the outer diameter of each level of annular spring baffle is greater than the inner diameter of the next level of annular spring baffle.

[0010] Optionally, a spring limiting boss is provided at one end of the second end cover, the spring limiting boss is a trapezoidal frustum structure with successively increasing diameters, and one end of the spring is connected to the limiting boss.

[0011] Optionally, the first end cover is provided with a main control ring cavity boss, which is used to form a main control ring cavity with the pressure measuring piston in an initial state, and push the pressure measuring piston to move after being connected to the main control pipe.

[0012] Optionally, each group of pressure gauges consists of two pressure gauges with the same range, and each group of pressure gauges is arranged in parallel.

[0013] Optionally, the pressure relief pipe, main control pipe and annular cavity interface pipe are all provided with ball valves or solenoid valves.

[0014] Optionally, the cavity is detachably connected to the first end cover and the second end cover.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention provides a pressure detection auxiliary device for water pressure testing, which is provided with a cavity, a pressure measuring piston and at least three groups of pressure gauge groups. When the pressure exceeds the effective range of the installed pressure gauge group of the lowest pressure level, the pressure measuring piston overcomes a spring force and moves to the right, closing the pipeline of the pressure gauge group of the lowest pressure level, and connecting the pipeline of the pressure gauge group with the pressure relief pipe to relieve the pressure, thereby preventing the pressure gauge group from being damaged by overpressure. At this time, the pressure gauge group of the middle pressure level is the effective working pressure gauge group. As the pressure continues to increase, the piston needs to overcome two spring forces to continue to compress. At this time, the pressure gauge group of the third pressure level is the effective working pressure gauge group, and the remaining pressure gauge pipelines are in a non-working state and are connected to the pressure relief pipe to relieve pressure. The working principle of the next level pressure gauge group is the same;

[0017] The present invention is an automatic pressure detection device. Before the test, there is no need to prepare pressure gauges of corresponding ranges according to valves of different pressure levels, which can eliminate human interference; and there is no need to replace the pressure gauges during the operation, which is simple to operate, saving time and effort; each level of the range group of pressure gauges is provided with a pressure relief pipe, when the range exceeds the lower level, the annular cavity is connected to the pressure relief pipe to relieve pressure, thereby protecting the lower level range pressure gauge group, reducing damage to the detection device, extending its service life, and realizing detection automation; the present invention can also adjust the range according to the different levels of valve test water pressure to increase the number of groups of pressure gauges in sequence, which is flexible, easy to operate, and has significant practical application and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The structure of a pressure detection auxiliary device for water pressure test of the present invention is schematically shown. Figure 1 ;

[0019] Figure 2 It is a structural schematic diagram of the pressure measuring piston of the present invention;

[0020] Figure 3 It is a structural schematic diagram of the cavity of the present invention;

[0021] Figure 4 The structure of the second end cover of the present invention is schematically shown in FIG. Figure 1 ;

[0022] Figure 5 The structure of the second end cover of the present invention is schematically shown in FIG. Figure 2 ;

[0023] Figure 6 The structure of the first end cover of the present invention is schematically shown in FIG. Figure 1 ;

[0024] Figure 7 The structure of the first end cover of the present invention is schematically shown in FIG. Figure 2 ;

[0025] Figure 8 The structure of a pressure detection auxiliary device for water pressure test of the present invention is schematically shown. Figure 2 ;

[0026] Fig. 9 The structure of a pressure detection auxiliary device for water pressure test of the present invention is schematically shown. Figure 3 ;

[0027] Fig.10 The structure of a pressure detection auxiliary device for water pressure test of the present invention is schematically shown. Figure 4 ;

[0028] Fig.11 The structure of a pressure detection auxiliary device for water pressure test of the present invention is schematically shown. Figure 5 ;

[0029] Fig.12 The structure of a pressure detection auxiliary device for water pressure test of the present invention is schematically shown. Figure 6 ;

[0030] Fig.13 The structure of a pressure detection auxiliary device for water pressure test of the present invention is schematically shown. Figure 7 ;

[0031] Fig.14 The structure of a pressure detection auxiliary device for water pressure test of the present invention is schematically shown. Figure 8 .

[0032] Description of reference numerals:

[0033] 1-first end cover, 2-second end cover, 4-main control ring cavity boss, 5-variable cross-section piston cavity, 6-step variable cross-section spring cavity, 7-1-main control pipe, 7-2-first ring cavity interface pipe, 7-3-second ring cavity interface pipe, 7-4-third ring cavity interface pipe, 8-11-first water-filled ring cavity, 8-12-first pressure measuring ring cavity, 8-13-first pressure relief ring cavity, 8-21-second water-filled ring cavity, 8-22-second pressure measuring ring cavity, 8-23-second pressure relief ring cavity, 8-31-third water-filled ring cavity, 8-32-third pressure measuring ring cavity, 8-33-third pressure relief ring cavity, 11-main control ring cavity, 12 -1-the first pressure gauge, 12-2-the second pressure gauge group, 12-3-the third pressure gauge group, 13-1-the first pressure relief pipe, 13-2-the second pressure relief pipe, 13-3-the third pressure relief pipe, 14-limiting boss, 15-1-the first pressure-bearing shoulder, 15-2-the second pressure-bearing shoulder, 15-3-the third pressure-bearing shoulder, 15-4-the fourth pressure-bearing shoulder, 15-5-the fifth pressure-bearing shoulder, 16-1-the first annular spring baffle, 16-2-the second annular spring baffle, 17-1-the first spring, 17-2-the second spring, 17-3-the third spring, 18-the cavity, 19-the spring limiting boss. DETAILED DESCRIPTION

[0034] In the description of the present invention, it should be noted that the terminology nouns in the various embodiments, such as "up", "down", "front", "back", "left", "right", etc., which indicate directions, are only for simplifying the description of the positional relationship based on the drawings in the specification, and do not mean that the referred elements and devices must be operated according to the specific directions and defined operations and methods and structures in the specification. Such directional nouns do not constitute a limitation on the present invention.

[0035] In the description of the present invention, it should be noted that the terms "first", "second" and "third" mentioned in the embodiments of the present invention are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or more of the features.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0037] Specific implementation plan 1: Combine Figures 1 to 3As shown, the present invention provides a pressure detection auxiliary device for water pressure test, including a cavity, a pressure measuring piston and N groups of pressure gauge groups, wherein N≥3, and N is an integer, a first end cover and a second end cover are respectively provided at both ends of the cavity, a variable cross-section piston cavity and a stepped variable cross-section spring cavity that are interconnected are provided in the cavity, a limited position boss is provided between the variable cross-section piston cavity and the stepped variable cross-section spring cavity, the variable cross-section piston cavity includes a main control ring cavity and N groups of ring cavities, the number of the pressure gauge group and the ring cavity is the same, the main control ring cavity is between the first end cover, the pressure measuring piston and the variable cross-section piston cavity, the main control ring cavity is connected to the main control pipe, and each group of ring cavities It is connected with the annular cavity interface pipe, a group of pressure gauge groups and the pressure relief pipe in sequence, and the ranges of the pressure gauge groups are arranged in sequence. The pressure measuring piston is built in the variable-section piston cavity, and the variable-section spring cavity is built with N-1 annular spring baffles and N springs. The number of the springs is the same as the number of the pressure gauge group, and the annular spring baffle is one less than the number of the pressure gauge group. The pressure output end of the pressure measuring piston is connected to one end of the adjacent spring, and the other end of the spring is connected to the second end cover. One end of the other spring is connected to the annular spring baffle, and the other end is connected to the second end cover. The springs pass through the next-level spring in sequence, and the pressure measuring piston is provided with a plurality of pressure-bearing shoulders;

[0038] By setting a cavity, a pressure measuring piston and at least three groups of pressure gauges, when the pressure exceeds the effective range of the installed lowest pressure level pressure gauge group, the pressure measuring piston overcomes the spring force and moves to the right, closing the pipeline of the lowest pressure level pressure gauge group, and connecting the pipeline of the pressure gauge group to the pressure relief pipe to relieve the pressure, thereby preventing overpressure from damaging the pressure gauge group. At this time, the intermediate pressure level pressure gauge group is the effective working pressure gauge group. As the pressure continues to increase, the piston needs to overcome two spring forces to continue to compress. At this time, the third pressure level pressure gauge group is the effective working pressure gauge group, and the pipelines of the remaining pressure gauge groups are all closed and connected to the pressure relief pipe for pressure relief. The working principle of the next level pressure gauge group is the same;

[0039] Specific implementation scheme one is an automatic pressure detection device. Before the test, there is no need to prepare pressure gauges of corresponding ranges according to valves of different pressure levels, which can eliminate human interference; and there is no need to replace the pressure gauges during the operation, which is simple to operate, saving time and effort; each level of the range group pressure gauge is provided with a pressure relief pipe. When the range exceeds the lower level, the pressure is relieved through the pressure relief pipe to protect the lower level range pressure gauge, reduce damage to the detection device, extend its service life, and realize detection automation; the present invention can also adjust the range according to the different levels of valve test water pressure and increase the number of pressure gauge groups in sequence. It is flexible, easy to operate, and has significant practical application and promotion value.

[0040] Specific implementation scheme 2: The annular cavity includes a water-filled annular cavity, a pressure-measuring annular cavity and a pressure-relief annular cavity. The diameters of the water-filled annular cavity, the pressure-measuring annular cavity and the pressure-relief annular cavity are larger than the diameters of the pressure-measuring piston. The water-filled annular cavity is connected to an annular cavity interface tube. The pressure-measuring annular cavity is connected to a group of pressure gauges through a pressure-measuring annular cavity outlet tube. The pressure-relief annular cavity is connected to a pressure-relief tube. The annular cavity is filled with water through an annular cavity interface tube to overcome the spring force of the spring, and to apply pressure to the pressure-measuring piston pressure-bearing shoulder to push the pressure-measuring piston to move, so that the annular cavity is connected to a pressure gauge group of a corresponding level for pressure measurement. The other combinations and connection relationships of this implementation scheme are the same as those of specific implementation scheme 1.

[0041] Specific implementation scheme three: The trapezoidal variable cross-section spring cavity is set as a truncated cone cavity with increasing diameters. The truncated cone cavity with the smallest diameter is provided with a spring, and the other truncated cone cavities are provided with annular spring baffles and springs. The outer diameter of each level of annular spring baffle is larger than the inner diameter of the next level of annular spring baffle; the number of annular spring baffles and springs can be adjusted according to the actual situation of the water pressure test, expanding the range of the pressure gauge and being more flexible; the spring is set with corresponding parameters according to the actual application. The other combinations and connection relationships of this implementation scheme are the same as those of specific implementation scheme one.

[0042] Specific implementation plan 4: Combination Figure 4 and Figure 5 As shown, a spring limiting boss is provided at one end of the second end cover, and the spring limiting boss is a trapezoidal truncated cone structure with successively increasing diameters, and one end of the spring is connected to the spring limiting boss; reducing the spring length can reduce the maximum value of the spring pressure during operation, and a pressure gauge group with a lower range can be selected; increasing the spring length can increase the maximum value of the spring pressure, and a pressure gauge group with a higher range can be selected. The other combinations and connection relationships of this implementation scheme are the same as those of the specific implementation scheme three.

[0043] Specific implementation plan five: Combination Figure 6 and Figure 7 As shown, the first end cover is provided with a main control ring cavity boss, which is used to form a main control ring cavity with the pressure measuring piston, and push the pressure measuring piston to move after being connected with the main control pipe; when filling water to measure pressure, the medium pressure of the main control ring cavity is the main pressure given to push the pressure measuring piston, and the medium pressure of the ring cavity is the secondary pressure to push the pressure measuring piston to move. The other combinations and connection relationships of this embodiment are the same as those of the specific embodiments one, two, three or four.

[0044] Specific implementation scheme six: the range ratio of the two adjacent groups of pressure gauges is 1:1.6; the ranges of the two adjacent groups of pressure gauges are set according to industry standards. The other combinations and connection relationships of this implementation scheme are the same as those of specific implementation scheme five.

[0045] Specific implementation scheme seven: Each group of pressure gauges comprises two pressure gauges of the same range, and each group of pressure gauges is arranged in parallel. The other combinations and connection relationships of this implementation scheme are the same as those of specific implementation scheme six.

[0046] Specific implementation scheme eight: The pressure relief pipe, main control pipe and annular cavity interface pipe are all provided with ball valves or solenoid valves. The other combinations and connection relationships of this implementation scheme are the same as those of specific implementation scheme seven.

[0047] Specific implementation scheme nine: The cavity is detachably connected to the first end cover and the second end cover. The piston, spring and annular spring baffle are assembled by opening the first end cover and the second end cover, which has practical application value. The other combinations and connection relationships of this implementation scheme are the same as those of specific implementation scheme eight.

[0048] Specific implementation plan 10: Combination Figures 8 to 14As shown, it includes a cavity, a pressure measuring piston, a first pressure gauge group, a second pressure gauge group and a third pressure gauge group, the first end cover and the second end cover are respectively arranged at both ends of the cavity, a variable cross-section piston cavity and a stepped variable cross-section spring cavity are arranged in the cavity, and are connected, a limited position boss is arranged between the variable cross-section piston cavity and the stepped variable cross-section spring cavity, the variable cross-section piston cavity includes a main control ring cavity, a first ring cavity, a second ring cavity and a third ring cavity, the first ring cavity includes a first water-filled ring cavity, a first pressure measuring ring cavity and a first pressure relief ring cavity, and the second ... The first end cover, the pressure measuring piston and the variable cross-section piston cavity are connected with the main control ring cavity, the main control ring cavity is connected with the main control pipe, the first water-filled ring cavity is connected with the first ring cavity interface pipe, the first pressure measuring ring cavity is connected with the first pressure gauge group, the first pressure relief ring cavity is connected with the first pressure relief pipe, the second water-filled ring cavity is connected with the second ring cavity interface pipe, the second pressure measuring ring cavity is connected with the second pressure gauge group, and the second pressure relief ring cavity is connected with the second pressure relief pipe. The third water-filled annular cavity is connected to the third annular cavity interface pipe, the third pressure measuring annular cavity is connected to the third pressure gauge group, the third pressure relief annular cavity is connected to the third pressure relief pipe, and the pressure gauge group ranges are arranged in sequence, the pressure measuring piston is built into the variable cross-section piston cavity, the variable cross-section piston cavity is built with an annular spring baffle and a spring, the annular spring baffle includes a first annular spring baffle, a second annular spring baffle and a third annular spring baffle, the spring includes a first spring, a second spring and a third spring, one end of the first spring is connected to the first annular spring baffle, and the other end is connected to the second end cover The second spring is connected to the second annular spring baffle at one end and to the second end cover at the other end; the third spring is connected to the third annular spring baffle at one end and to the second end cover at the other end; the first spring runs through the second spring, the second spring runs through the third spring, the pressure output end of the pressure measuring piston is connected to the first annular spring baffle; the pressure measuring piston is provided with a plurality of pressure-bearing shoulders, including a first pressure-bearing shoulder, a second pressure-bearing shoulder, a third pressure-bearing shoulder, a fourth pressure-bearing shoulder and a fifth pressure-bearing shoulder; an annular cavity is formed between two adjacent pressure-bearing shoulders and the variable-section piston cavity;

[0049] When in the effective range of the third pressure gauge group, the main control annular cavity is connected to the main control connecting pipe, the first water-filled annular cavity is connected to the first annular cavity interface pipe, the second water-filled annular cavity is connected to the second annular cavity interface pipe, the third water-filled annular cavity is connected to the third annular cavity interface pipe, the third annular cavity is connected to the third pressure gauge group, the third annular cavity is not connected to the third pressure relief pipe, the second annular cavity is not connected to the second pressure gauge group and the second pressure relief pipe, and the first annular cavity is not connected to the first pressure gauge group and the first pressure relief pipe; when in the effective range of the second pressure gauge group, the first water-filled annular cavity is connected to the first annular cavity interface pipe, the second water-filled annular cavity is connected to the second annular cavity interface pipe, the third water-filled annular cavity is connected to the third annular cavity interface pipe, the third annular cavity is connected to the third pressure gauge group, the third annular cavity is not connected to the third pressure relief pipe, the second annular cavity is not connected to the second pressure gauge group and the second pressure relief pipe, and the first annular cavity is not connected to the first pressure gauge group and the first pressure relief pipe; The first annular cavity is connected to the second pressure gauge group and is not connected to the second pressure relief pipe, the second annular cavity is connected to the second pressure gauge group and is not connected to the second pressure relief pipe, and the third annular cavity is not connected to the third pressure gauge group and the third pressure relief pipe; when in the effective range of the first pressure gauge group, the third annular cavity is not connected to the third pressure gauge group and the third pressure relief pipe, the second annular cavity is not connected to the second pressure gauge group and the second pressure relief pipe, and the first annular cavity is connected to the first pressure gauge group and is not connected to the first pressure relief pipe. Other combinations and connection relationships of this embodiment are the same as those of the ninth embodiment.

[0050] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

[0051] Working principle: Taking specific implementation plan ten as an example, the main control annular cavity is connected to the main control connecting pipe, the first water-filled annular cavity is connected to the first annular cavity interface pipe, the second water-filled annular cavity is connected to the second annular cavity interface pipe, and the third water-filled annular cavity is connected to the third annular cavity interface pipe. When the third pressure gauge group is in the effective range, the spring force of the first spring is overcome, and the third pressure gauge group is connected to the third annular cavity for pressure measurement. The third annular cavity is not connected to the third pressure relief pipe, the second annular cavity is not connected to the second pressure gauge group and the second pressure relief pipe, the first annular cavity is not connected to the first pressure gauge group and the first pressure relief pipe, the third pressure gauge group is in a working state, and the second pressure gauge group and the first pressure gauge group are not in a working state. When the water pressure increases, the spring force of the first spring and the second spring is overcome to push the pressure measuring piston to move. When the second pressure gauge group is in the effective range, the third annular cavity is connected to the third pressure gauge group and the third pressure relief pipe. The pressure pipe is in a connected state, which is used to prevent the third pressure gauge group from being damaged. The second annular cavity is in a connected state with the second pressure gauge group, and is not connected with the second pressure relief pipe. The first annular cavity is in a connected state with the first pressure gauge group, and is not connected with the first pressure relief pipe. At this time, the second pressure gauge group is in a working state, and the first pressure gauge group and the third pressure gauge group are in a non-working state. When the pressure continues to increase, it is in the effective range of the first pressure gauge group, overcoming the spring force of the first spring, the second spring and the third spring, and pushing the pressure measuring spring to continue to move. The third annular cavity is not connected with the third pressure gauge group and the third pressure relief pipe, the second annular cavity is not connected with the second pressure gauge group and the second pressure relief pipe, the first annular cavity is in a connected state with the first pressure gauge group, and is not connected with the first pressure relief pipe. At this time, the second pressure gauge group and the first pressure gauge group are in a non-working state, and the first pressure gauge group is in a working state.

Claims

1. A pressure detection auxiliary device for water pressure test, characterized in that: The invention comprises a cavity (18), a pressure measuring piston and N groups of pressure gauges, wherein N is greater than or equal to 3 and N is an integer. The two ends of the cavity (18) are respectively provided with a first end cover (1) and a second end cover (2). The cavity (18) is provided with a variable cross-section piston cavity (5) and a stepped variable cross-section spring cavity (6) which are interconnected. A limiting boss (14) is provided between the variable cross-section piston cavity (5) and the stepped variable cross-section spring cavity (6). The variable cross-section piston cavity (5) comprises a main control ring cavity (11) and N groups of ring cavities. The number of the pressure gauge group and the ring cavity is the same. The main control ring cavity (11) is provided between the first end cover (1), the pressure measuring piston and the variable cross-section piston cavity (5). The main control ring cavity (11) is connected to the main control pipe. (7-1), each group of annular cavities is connected to annular cavity interface tubes, a group of pressure gauge groups and pressure relief pipes in sequence, and the pressure gauge group ranges are arranged in sequence. The pressure measuring piston is built into the variable-section piston cavity (5), and the variable-section spring cavity (6) is built with N-1 annular spring baffles and N springs. The number of the springs is the same as the number of the pressure gauge groups, and the annular spring baffle is one less than the number of the pressure gauge groups. The pressure output end of the pressure measuring piston is connected to one end of the adjacent spring, and the other end of the spring is connected to the second end cover (2). One end of the other springs is connected to the annular spring baffle, and the other end is connected to the second end cover (2). The springs pass through the next-level springs in sequence, and the pressure measuring piston is provided with a plurality of pressure-bearing shoulders.

2. A pressure detection auxiliary device for water pressure test according to claim 1, characterized in that: The annular cavity comprises a water-filled annular cavity, a pressure-measuring annular cavity and a pressure-relief annular cavity. The diameters of the water-filled annular cavity, the pressure-measuring annular cavity and the pressure-relief annular cavity are larger than the diameters of the pressure-measuring piston. The water-filled annular cavity is connected to the annular cavity interface tube, the pressure-measuring annular cavity is connected to a group of pressure gauges, and the pressure-relief annular cavity is connected to the pressure-relief pipe.

3. A pressure detection auxiliary device for water pressure test according to claim 1, characterized in that: The stepped variable cross-section spring cavity (6) is configured as a truncated cone cavity with successively increasing diameters, a spring is disposed in the truncated cone cavity with the smallest diameter, and annular spring baffles and springs are disposed in the other truncated cone cavities, wherein the outer diameter of each level of annular spring baffles is greater than the inner diameter of the next level of annular spring baffles.

4. A pressure detection auxiliary device for water pressure test according to claim 3, characterized in that: A spring limiting boss (19) is provided at one end of the second end cover (2); the spring limiting boss (19) is a trapezoidal frustum structure with successively increasing diameters; one end of the spring is connected to the spring limiting boss (19).

5. A pressure detection auxiliary device for water pressure test according to any one of claims 1 to 4, characterized in that: The first end cover (1) is provided with a main control ring cavity boss (4) for forming a main control ring cavity (11) with the pressure measuring piston and pushing the pressure measuring piston to move after being connected with the main control pipe (7-1).

6. A pressure detection auxiliary device for water pressure test according to claim 5, characterized in that: Each set of pressure gauges consists of two pressure gauges with the same range, and each set of pressure gauges is arranged in parallel.

7. A pressure detection auxiliary device for water pressure test according to claim 6, characterized in that: The pressure relief pipe, the main control pipe (7-1) and the annular cavity interface pipe are all provided with a ball valve or a solenoid valve.

8. A pressure detection auxiliary device for water pressure test according to claim 7, characterized in that: The cavity (18) is detachably connected to the first end cover (1) and the second end cover (2).

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