Pressure measuring instrument

Abstract

The invention belongs to the technical field of pressure measuring instruments, and particularly relates to a pressure measuring instrument, which comprises a pressure measuring assembly and a detection assembly, and is characterized in that the pressure measuring assembly is used for measuring air pressure in a pipeline and performing measurement precision detection on an air pressure range greater than the air pressure in the pipeline in a pressure measuring state; the detection assembly is used for carrying out measurement precision detection on an air pressure range smaller than the air pressure in the pipeline through cooperation with the pressure measurement assembly in the pressure measurement state. The device does not need to be dismounted from the pipeline during measurement precision detection in different pressure value ranges, the pipeline does not need to be shut down, and continuous and normal operation of related equipment is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of pressure measuring instruments, and in particular relates to a pressure measuring instrument. Background Art

[0002] A pressure measuring instrument is an instrument used to measure the pressure of gas or liquid in a pipeline. It can indicate and record the pressure value of gas or liquid in the pipeline in real time.

[0003] A commonly used pressure measuring instrument is a Bourdon tube measuring instrument, which has a hollow C-shaped copper-based Bourdon tube as a sensitive element. The cross-section of the Bourdon tube is elliptical or flat. One end of the Bourdon tube is fixed and the other end is suspended. When the Bourdon tube is filled with gas or liquid with a certain pressure, the Bourdon tube will produce a certain degree of deformation, and the suspended end of the Bourdon tube will produce a certain displacement. The displaced end will drive the pointer of the displaced end to swing a certain amplitude through a series of transmissions and indicate the pressure value on the dial. This pressure value is the pressure of the gas or liquid filled in the Bourdon tube.

[0004] When the Bourdon tube pressure gauge is manufactured, its measuring accuracy is tested. After the pressure gauge has been working for a period of time, it is sent back to the original factory for testing to ensure its measuring accuracy. The disassembly of the pressure gauge requires shutting down the pipeline it is measuring, which affects the operation of the equipment.

[0005] The present invention improves the Bourdon tube structure in the pressure measuring instrument so that the pressure measuring instrument can be tested for its measurement accuracy without disassembling while the pressure measuring instrument is in normal operation. Summary of the Invention

[0006] Based on this, it is necessary to provide a pressure measuring instrument to address the problems existing in current pressure measuring instruments. The present invention can complete its own measurement accuracy detection without disassembling the pipeline through a pressure measuring component and a detection component.

[0007] The above purpose is achieved through the following technical solutions: A pressure measuring instrument is used to measure the pressure of gas in a pipeline and to detect its own measurement accuracy, comprising: The pressure measuring component arranged in the circular shell is used to measure the air pressure in the pipeline and to perform measurement accuracy detection on the air pressure range greater than the air pressure in the pipeline under the pressure measuring state.

[0008] The detection component is arranged in the round shell and is transmission-connected to the pressure measuring component. It is used to perform measurement accuracy detection on the air pressure range that is smaller than the air pressure in the pipeline by cooperating with the pressure measuring component in the pressure measuring state.

[0009] In one embodiment, the pressure measuring assembly includes a first Bourdon tube disposed in a circular shell and coaxial with the circular shell, a second air pipe communicating with the interior of the first Bourdon tube and threadedly connected to a branch pipe on the pipeline is disposed at one end of the first Bourdon tube, the second air pipe being fixed in a first slot on the wall of the circular shell, a third air pipe communicating with the interior of the first Bourdon tube being disposed on the outer side of the first Bourdon tube, the third air pipe being engaged with the second slot on the wall of the circular shell, a thin film capsule communicating with the second air pipe being disposed on the inner wall of the first Bourdon tube, the inner arc wall of the thin film capsule being glued to the inner arc wall of the first Bourdon tube, and a portion of the thin film capsule being disposed so as to connect the second air pipe and the third air pipe. The area between the trachea is opened and tightly attached to the opening sleeve of the inner wall of the first Bourdon tube. The suspended end of the first Bourdon tube is hingedly connected to a first connecting rod via a first hinge pin. The end of the first connecting rod is hingedly connected to one end of a swing arm. A fixing pin is rotatably provided in a central circular hole of the swing arm. The fixing pin is fixed to the inner wall of the circular shell. The other end of the swing arm is provided with an arc rack coaxial with the fixing pin. The arc rack meshes with a gear on a rotating shaft. The rotating shaft is rotatably provided on the inner wall of the circular shell and coaxial with the circular shell. The rotating shaft rotates in a circular hole in the middle of a dial in the circular shell. A pointer for indicating the pressure value scale on the dial is provided on the rotating shaft.

[0010] In one embodiment, the third tracheal side end of the open-mouth cuff is provided with a semi-ring cuff to prevent the membrane sac from being squeezed and closed when air is inflated into the first Bourdon tube through the third trachea.

[0011] In one embodiment, a positioning ring is provided on the second air pipe, and the positioning ring is fixed to the boss at the notch of the first slot by bolts. The suspended end of the first Bourdon tube is provided with a first lug, and the first lug is hinged to the first connecting rod through a first hinge pin.

[0012] In one embodiment, the pointer is fixed on a ring on the rotating shaft, and the rotating shaft is rotatably arranged in a first rotating seat. A ring plate is provided on the first rotating seat, and the ring plate is fixed to the inner wall of the circular shell by bolts, and the fixing pin is fixed to the ring plate.

[0013] In one embodiment, the detection assembly includes a lock assembly disposed on the wall of the circular shell and a second waveden tube disposed within the circular shell and coaxial with the circular shell. The dimensions, specifications, and performance of the second waveden tube are the same as those of the first waveden tube. A slider is disposed at one end of the second waveden tube, which cooperates with the lock assembly. The slider-side end of the second waveden tube is circumferentially spaced 180 degrees from the fixed end of the first waveden tube. The slider is slidably disposed within a guide seat on the inner wall of the circular shell about the axis of the second waveden tube. A hose is disposed at the slider-side end of the second waveden tube, connecting it to the first air pipe on the wall of the circular shell. A return spring is disposed within the guide seat to maintain a circumferential spacing of 180 degrees between the slider-side end of the second waveden tube and the fixed end of the first waveden tube. The two ends of the return spring are respectively connected to the inner wall of the guide seat and the slider. A second lug is disposed at the other end of the second waveden tube. The second lug is hingedly connected to one end of a second connecting rod via a second hinge pin. The other end of the second connecting rod is hingedly connected to the first lug at the end of the first waveden tube via a first hinge pin.

[0014] In one embodiment, the slider is provided with a first anti-slip groove that cooperates with the lock assembly.

[0015] In one embodiment, the lock assembly includes a screw, the screw thread is set in a threaded sleeve on the wall of the circular shell, the inner end of the screw is rotatably provided with a second swivel seat, the second swivel seat is provided with an arc plate that cooperates with the slider, the arc plate is provided with a second tooth pattern that cooperates with the first tooth pattern, the arc plate is provided with a guide hole that slides with the guide rod on the inner wall of the circular shell, and the outer end of the screw is provided with a torsion wheel.

[0016] In one embodiment, a first limiting ring for limiting the position of the dial is provided inside the circular shell, a transparent shell cover is provided on the outside of the dial and is spaced apart from the dial, a spacer ring is provided between the shell cover and the dial, and a second limiting ring is provided at the end of the circular shell to fix the shell cover by bolts.

[0017] In one embodiment, the second limiting ring is provided with a first blocking bar and a second blocking bar for shielding the first slot and the second slot respectively.

[0018] The beneficial effects of the present invention are: 1. After the locking assembly locks the end of the second wave tube in the detection assembly, the pressure measuring assembly of the present invention charges the second wave tube with gas of different pressures measured in the small air pressure pipeline via a first air pipe connected to the hose at the locking end of the second wave tube. As a result, the second wave tube, under the action of the gas at different pressures, causes the suspended end of the first wave tube to deform to varying degrees via a second connecting rod, causing a pointer to indicate different pressure values. The different pressure values ​​indicated on the dial are compared with one-half the pressure of the gas charged into the second wave tube, thereby achieving measurement accuracy testing within a pressure range less than the measured pressure in the pipeline.

[0019] 2. The pressure measuring assembly of the present invention accurately measures gas pressure by filling a thin film bladder bonded to the inner arc wall of the first Bourdon tube with gas through a second air pipe at the fixed end of the first Bourdon tube. The present invention repeatedly fills the gap between the bladder and the first Bourdon tube with gas at varying pressures greater than the pressure within the bladder, causing the gas within the bladder to be discharged and fill the first Bourdon tube. The first Bourdon tube deforms to varying degrees under the action of the different pressures, causing the indicator to indicate different pressures. The different pressures indicated on the indicator dial are compared with the corresponding pressures of the gas filled in the first Bourdon tube, thereby achieving measurement accuracy within a range of pressures greater than the pressure within the bladder, i.e., greater than the pressure within the pipeline measured by the present invention.

[0020] 3. The present invention does not need to be removed from the pipeline when performing measurement accuracy testing in different pressure value ranges, and there is no need to shut down the pipeline, ensuring the continuous normal operation of related equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a first overall schematic diagram of the present invention connected to a pipeline; Figure 2 is a second overall schematic diagram of the present invention connected to a pipeline; Figure 3 This is a schematic diagram of the cooperation between the pointer and the dial in the present invention; Figure 4 is a first cross-sectional view of the present invention; Figure 5 It is a cross-sectional view of the present invention; Figure 6 is a second cross-sectional view of the present invention; Figure 7 This is a cross-sectional view of the lock assembly and the detection assembly in the present invention; Figure 8 This is a cross-sectional view of the pressure measuring component and the detection component in the present invention; Figure 9 It is a longitudinal sectional view of the present invention; Figure 10It is a circular shell structure and its cross-sectional view; Figure 11 This is a schematic diagram of the first wave of tube boarding structure; Figure 12 It is a schematic diagram of the structure of the opening sleeve in the pressure measuring assembly; Figure 13 This is a schematic diagram of the second wave of tube boarding structure; Figure 14 It is a schematic diagram of the arc plate structure in the lock assembly; Figure 15 2 is a schematic diagram of the structure of the second limiting ring; Figure 16 This is a schematic diagram of the pressure measurement and detection states of the membrane bladder in the first Bourdon tube; Name of the label in the figure: 101, pipe; 102, branch pipe; 103, round shell; 104, first slot; 105, second slot; 106, boss; 107, screw sleeve; 108, first air pipe; 109, first limiting ring; 110, spacer ring; 111, shell cover; 112, second limiting ring; 113, first stop bar; 114, second stop bar; 200, pressure measuring assembly; 201, second air tube; 202, positioning ring; 203, first Bourdon tube; 204, third air tube; 205, membrane bladder; 206, opening sleeve; 207, semi-ring sleeve; 208, first lug; 209, first hinge pin; 210, first connecting rod; 211, swing arm; 212, fixing pin; 214, arc rack; 215, ring plate; 216, first swivel seat; 217, rotating shaft; 218, gear; 219, ring; 220, pointer; 221, dial; 300, detection assembly; 301, guide seat; 302, guide rod; 303, slider; 304, first tooth pattern; 305, second Bourdon tube; 306, second lug; 307, hose; 308, lock assembly; 309, arc plate; 310, second tooth pattern; 311, second swivel seat; 312, screw; 313, torsion wheel; 314, second hinge pin; 315, second connecting rod; 316, return spring. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0023] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings). In the description of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like, indicating positions or relationships, are based on those shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the device or element referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention.

[0024] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0025] like Figure 1-16 As shown, a pressure measuring instrument is used to measure the pressure of gas in pipeline 101 and detect its own measurement accuracy, including: The pressure measuring assembly 200 disposed in the circular shell 103 is used to measure the air pressure in the pipeline 101 and to perform measurement accuracy detection on an air pressure range greater than the air pressure in the pipeline 101 under the pressure measuring state.

[0026] The detection component 300 is arranged in the circular shell 103 and is transmission-connected to the pressure measuring component 200 , and is used to perform measurement accuracy detection on the air pressure range smaller than the air pressure in the pipeline 101 by cooperating with the pressure measuring component 200 in the pressure measuring state.

[0027] In a further embodiment, Figure 3 、 Figure 4 、 Figure 5 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 16As shown, the pressure measuring assembly 200 includes a first Bourdon tube 203 disposed in the circular shell 103 and coaxial with the circular shell 103. One end of the first Bourdon tube 203 is provided with a second air pipe 201 that is in communication with the interior thereof and is threadedly connected to the branch pipe 102 on the pipeline 101. The second air pipe 201 is fixed in a first slot 104 on the shell wall of the circular shell 103. A third air pipe 204 that is in communication with the interior thereof is provided on the outer side of the first Bourdon tube 203. The third air pipe 204 cooperates with the second slot 105 on the shell wall of the circular shell 103. A film capsule 205 that is in communication with the second air pipe 201 is provided on the inner wall of the first Bourdon tube 203. The inner arc wall of the film capsule 205 is glued to the inner arc wall of the first Bourdon tube 203. A portion of the film capsule 205 that is located between the second air pipe 201 and the third air pipe 204 is provided in the film capsule 205. The opening sleeve 206 is opened and tightly attached to the inner wall of the first Bourdon tube 203. The suspended end of the first Bourdon tube 203 is hingedly connected to a first connecting rod 210 via a first hinge pin 209. The end of the first connecting rod 210 is hingedly connected to one end of a swing arm 211. A fixing pin 212 is rotatably provided in a central circular hole of the swing arm 211. The fixing pin 212 is fixed to the inner wall of the circular shell 103. The other end of the swing arm 211 is provided with an arc rack 214 coaxial with the fixing pin 212. The arc rack 214 meshes with a gear 218 on a rotating shaft 217. The rotating shaft 217 is rotatably provided on the inner wall of the circular shell 103 and coaxial with the circular shell 103. The rotating shaft 217 rotates in a circular hole in the middle of a dial 221 in the circular shell 103. A pointer 220 for indicating the pressure value scale on the dial 221 is provided on the rotating shaft 217.

[0028] In a further embodiment, Figure 5 、 Figure 12 、 Figure 16 As shown, the end portion of the opening sleeve 206 on the side of the third trachea 204 is provided with a semi-annular sleeve 207 to prevent the film bag 205 from being squeezed and closed when air is inflated into the first Bourdon tube 203 through the third trachea 204 .

[0029] In a further embodiment, Figure 4 、 Figure 5 、 Figure 11 、 Figure 12 As shown, a positioning ring 202 is provided on the second air pipe 201, and the positioning ring 202 is fixed to the boss 106 at the notch of the first slot 104 by bolts. The suspended end of the first Bourdon tube 203 is provided with a first lug 208, and the first lug 208 is hinged to the first connecting rod 210 through a first hinge pin 209.

[0030] In a further embodiment, Figure 3 、 9As shown, the pointer 220 is fixed on the ring 219 on the rotating shaft 217, and the rotating shaft 217 is rotatably set in the first rotating seat 216. A ring plate 215 is set on the first rotating seat 216. The ring plate 215 is fixed to the inner wall of the circular shell 103 by bolts, and the fixing pin 212 is fixed on the ring plate 215.

[0031] In a further embodiment, Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 13 、 Figure 14 As shown, the detection assembly 300 includes a lock assembly 308 disposed on the wall of the circular shell 103 and a second wave tube 305 disposed in the circular shell 103 and coaxial with the circular shell 103. The size, specifications and performance of the second wave tube 305 are the same as those of the first wave tube 203. A slider 303 is provided at one end of the second wave tube 305 to cooperate with the lock assembly 308. The end portion of the slider 303 of the second wave tube 305 is 180 degrees circumferentially away from the fixed end of the first wave tube 203. The slider 303 is slidably disposed around the axis of the second wave tube 305 in a guide seat 301 on the inner wall of the circular shell 103. The slider 303 of the second wave tube 305 is provided on the side of the guide seat 301. A hose 307 is provided at one end thereof, connecting it to the first air pipe 108 on the wall of the circular shell 103. A return spring 316 is provided within the guide seat 301, which maintains a circumferential spacing of 180 degrees between the end of the second bourdon tube 305 on the slider 303 side and the fixed end of the first bourdon tube 203. The two ends of the return spring 316 are respectively connected to the inner wall of the guide seat 301 and the slider 303. A second lug 306 is provided at the other end of the second bourdon tube 305. The second lug 306 is hingedly connected to one end of a second connecting rod 315 via a second hinge pin 314. The other end of the second connecting rod 315 is hingedly connected to the first lug 208 at the end of the first bourdon tube 203 via a first hinge pin 209.

[0032] In a further embodiment, Figure 13 As shown, the slider 303 is provided with a first anti-slip groove that cooperates with the lock assembly 308 .

[0033] In a further embodiment, Figure 7 、 Figure 9 、 Figure 14As shown, the lock assembly 308 includes a screw 312, which is threadedly arranged in a threaded sleeve 107 on the wall of the circular shell 103. The inner end of the screw 312 is rotatably provided with a second swivel seat 311, and the second swivel seat 311 is provided with an arc plate 309 that cooperates with the slider 303. The arc plate 309 is provided with a second tooth pattern 310 that cooperates with the first tooth pattern 304. The arc plate 309 is provided with a guide hole that slides with the guide rod 302 on the inner wall of the circular shell 103, and the outer end of the screw 312 is provided with a torsion wheel 313.

[0034] In a further embodiment, Figure 9 、 Figure 10 As shown, a first limiting ring 109 for limiting the position of the dial 221 is provided in the circular shell 103, a transparent shell cover 111 is provided on the outer side of the dial 221 and is spaced apart from the dial 221, a spacer ring 110 is provided between the shell cover 111 and the dial 221, and a second limiting ring 112 is provided at the end of the circular shell 103 to fix the shell cover 111 by bolts.

[0035] In a further embodiment, Figure 9 、 Figure 10 、 Figure 15 As shown, the second limiting ring 112 is provided with a first blocking bar 113 and a second blocking bar 114 for shielding the first slot 104 and the second slot 105 respectively.

[0036] After the lock assembly 308 locks the end of the second conduit 305 in the detection assembly 300, the pressure measuring assembly 200 of the present invention fills the second conduit 305 with gas of different pressures measured in the small air pressure pipe 101 through the first air pipe 108 connected to the hose 307 at the locking end of the second conduit 305. Under the action of the gas at different pressures, the second conduit 305 causes the suspended end of the first conduit 203 to deform to varying degrees via the second connecting rod 315, thereby causing the pointer 220 to indicate different pressure values. The different pressure values ​​indicated on the dial 221 are compared with half the pressure of the gas filled in the second conduit 305, thereby completing the measurement accuracy test within a pressure range less than the measured pressure in the pipe 101. The pressure measuring assembly 200 of the present invention accurately measures gas pressure by filling a membrane bladder 205 bonded to the inner arc wall of the first conduit 203 with gas via a second air pipe 201 at the fixed end of the first conduit 203. The present invention also repeatedly fills the gap between the membrane bladder 205 and the first conduit 203 with gas at varying pressures greater than the pressure within the membrane bladder 205. This causes the gas within the membrane bladder 205 to be discharged and fill the first conduit 203. This causes the first conduit 203 to deform to varying degrees under the action of the gas at varying pressures, driving the pointer 220 to indicate different pressure values. The different pressure values ​​indicated on the dial 221 are compared with the corresponding pressures of the gas filled in the first conduit 203, thereby achieving measurement accuracy within a range of pressures greater than the pressure within the membrane bladder 205, i.e., greater than the pressure within the pipeline 101 measured by the present invention. The present invention does not need to be removed from the pipeline 101 when performing measurement accuracy testing in different pressure value ranges, and there is no need to shut down the pipeline 101, thereby ensuring that related equipment continues to operate normally.

[0037] The elastic coefficient of the return spring 316 in the present invention is extremely small, and its effect on the phase change displacement of the first Bourdon tube 203 is negligible, and does not affect the accurate measurement of the gas pressure by the first Bourdon tube 203 .

[0038] The operation process of the present invention is as follows: In the initial state, the slider 303-side end of the second conduit tube 305 in the detection assembly 300 is circumferentially spaced 180 degrees from the fixed end of the first conduit tube 203 in the load-measuring assembly 200. The return spring 316 is in a stretched state, and the arc plate 309 in the lock assembly 308 is in an unlocked state with respect to the slider 303 in the detection assembly 300. Both the second conduit tube 305 in the detection assembly 300 and the first conduit tube 203 in the load-measuring assembly 200 are in a naturally deformed state. The wall of the membrane bladder 205 in the first conduit tube 203 of the load-measuring assembly 200 is in close contact with the inner wall of the first conduit tube 203.

[0039] Before it leaves the factory, its measurement accuracy is tested. The specific operations are as follows: First, gas at different pressures is sequentially injected into the membrane bladder 205 in the first conduit tube 203 from the second air pipe 201 of the pressure measuring assembly 200. Each time a certain pressure is injected, the suspended end of the first conduit tube 203 deforms and displaces accordingly. The suspended end of the first conduit tube 203, via the first connecting rod 210, drives the swing arm 211 to swing about the fixed pin 212. The swing arm 211, via the arc-shaped rack 214, gear 218, and rotating shaft 217, drives the pointer 220 to swing a certain amplitude to indicate a specific pressure value on the dial 221. Simultaneously, the displaced suspended end of the first conduit tube 203, via the second connecting rod 315, drives the second conduit tube 305 to correspondingly displace about its own axis, overcoming the elastic force of the return spring 316, further stretching the return spring 316.

[0040] Compare the pressure indicated by pointer 220 with the corresponding pressure of the gas filled in membrane bladder 205. If the two values ​​are equal, the pressure measuring instrument's measurement accuracy is correct. If the two values ​​are not equal, the pressure measuring instrument's measurement accuracy is problematic and needs to be returned to the factory for calibration. After the test is completed, stop filling membrane bladder 205 with gas. The first burden tube 203 returns to its original position due to its own elastic force, and the second burden tube 305 returns to its original position due to the return spring 316.

[0041] Secondly, if the measurement accuracy detected above is correct, then proceed to the next stage of testing. The specific operations are as follows: The torsion wheel 313 is rotated, and through the screw 312 and the screw sleeve 107, the torsion wheel 313 drives the arc plate 309 along the guide rod 302 to press against the slider 303 in the detection assembly 300. The second teeth 310 on the arc plate 309 engage with the first teeth 304 on the slider 303, thereby locking the slider 303. Then, gas at a pressure of P1 is injected into the membrane bladder 205 in the first boden tube 203 through the second air pipe 201, causing the suspended end of the first boden tube 203 to undergo a certain displacement due to deformation. The first boden tube 203 drives the pointer 220 to swing a certain amplitude and indicate a scale value on the dial 221 that is less than P1. The suspended end of the first boden tube 203 drives the suspended end of the second boden tube 305 to undergo a certain displacement via the second connecting rod 315. Next, gas at a pressure of P1 is introduced into the second waveguide tube 305 through the first air pipe 108 and the hose 307. The free end of the second waveguide tube 305 deforms and displaces. This, in turn, drives the free end of the first waveguide tube 203 to displace via the second connecting rod 315. This causes the free end of the first waveguide tube 203 to cause the pointer 220 to eventually indicate a decrease in the pressure scale value on the dial 221. If the pointer 220 is finally indicated by the first waveguide tube 203 at the P1 scale value on the dial 221, the pressure measuring instrument's measurement accuracy for P1 meets the requirements; otherwise, the pressure measuring instrument fails the requirements. Following the above process, multiple gases with different P2 values ​​are sequentially introduced into second Bourdon tube 305 through first gas pipe 108, with P2 being less than P1. If the final scale value indicated by pointer 220 each time is equal to P1 - P2, etc., the pressure measuring instrument's measurement accuracy for each P2 value less than P1 is acceptable; otherwise, it fails. This completes the measurement accuracy test of the pressure measuring instrument within the pressure range less than P1.

[0042] Next, the inflation of air into the second conduit 305 through the first air pipe 108 is stopped while maintaining the air pressure P1 in the membrane bladder 205. The torsion wheel 313 is rotated in the opposite direction. The torsion wheel 313 drives the arc plate 309 along the guide rod 302 to disengage from the slider 303 via the screw 312 and the screw sleeve 107, thereby releasing the lock on the slider 303. Driven by the first conduit 203, the second conduit 305 overcomes the return spring 316 to move a certain range around its own axis and returns to its original shape without deformation. Then, gas of different values ​​P3 is sequentially filled into the first conduit tube 203 through the third air pipe 204. The gas P3 is greater than P1 but less than or equal to the maximum range on the dial 221. The gas of value P3 entering the first conduit tube 203 discharges the gas of value P1 in the membrane capsule 205 through the second air pipe 201. Finally, the first conduit tube 203 is filled with gas of value P3, causing the suspended end of the first conduit tube 203 to produce a certain displacement due to deformation, and the first conduit tube 203 drives the pointer 220 to swing a certain amount. The amplitude finally indicates a scale value on the dial 221, and the indicated scale value is greater than P1 but less than or equal to the maximum range on the dial 221. The suspended end of the first corundum tube 203 drives the second corundum tube 305 through the second connecting rod 315 to continue to overcome the return spring 316 to generate a larger displacement. If the first corundum tube 203 drives the pointer 220 to finally indicate the scale value P3 on the dial 221, it indicates that the measurement accuracy of the pressure measuring instrument for different values ​​of P3 is qualified, otherwise it is unqualified.

[0043] This concludes the factory inspection of the pressure measuring instrument.

[0044] When the present invention is shipped for use, the second air pipe 201 must be sealed and connected to the branch pipe 102 on the pipeline 101 where the P1 gas to be measured resides. Lock assembly 308 unlocks slider 303. Once the second air pipe 201 and branch pipe 102 are connected, the on / off valve on branch pipe 102 is opened. Gas in pipeline 101 flows through branch pipe 102, second air pipe 201, and the opening at one end of the film bladder 205 opened by opening sleeve 206, filling the film bladder 205. This causes the free end of the first burden tube 203 to deform and displace. This free end, through a series of transmission mechanisms, drives pointer 220 to indicate P1 on dial 221. Simultaneously, the free end of the first burden tube 203 causes the second burden tube 305 to displace a certain distance around its axis, overcoming return spring 316.

[0045] After the pressure measuring instrument has been used for a period of time, it is necessary to test its own measurement accuracy. The specific operation of the test is as follows: First, keep P1 gas flowing into the first Bourdon tube 203 through the second air pipe 201, rotate the twist wheel 313, and the twist wheel 313 drives the arc plate 309 along the guide rod 302 to press the slider 303 in the detection component 300 through the screw 312 and the screw sleeve 107. The second tooth pattern 310 on the arc plate 309 and the first tooth pattern 304 on the slider 303 engage with each other, thereby completing the locking of the slider 303. Then, gas at a pressure of P1 is introduced into the second wave tube 305 through the first air pipe 108 and the hose 307. The free end of the second wave tube 305 deforms and displaces. This, in turn, drives the free end of the first wave tube 203 via the second connecting rod 315. This causes the free end of the first wave tube 203 to move, causing the pointer 220 to decrease the pressure on the dial 221. If the pointer 220 finally indicates the P1 mark on the dial 221, the pressure gauge's accuracy for P1 is acceptable. Otherwise, it fails. Following the above process, multiple gas pressures of different values, P2, are sequentially introduced into the second wave tube 305 through the first air pipe 108, with P2 being less than P1. If the pointer 220's final indication on each scale equals P1 - P2, the pressure gauge's accuracy for each value of P2 less than P1 is acceptable. Otherwise, it fails. From now on, the measurement accuracy test of the pressure measuring instrument itself in the air pressure range less than P1 is completed.

[0046] Next, the inflation of air into the second Bourdon tube 305 through the first air pipe 108 is stopped while the first air pipe 108 continues to inflate the film bladder 205 with air at a value of P1. The first Bourdon tube 203 drives the pointer 220 to indicate P1 on the dial 221 again. The torsion wheel 313 is rotated in the reverse direction. The torsion wheel 313 drives the arc plate 309 along the guide rod 302 via the screw 312 and the screw sleeve 107 to disengage the slider 303 and release the slider 303 from the lock. Then, gases of different values ​​P3 are sequentially filled into the first conduit tube 203 through the third air pipe 204. The gas P3 is greater than P1 but less than or equal to the maximum range on the dial 221. The gas of value P3 entering the first conduit tube 203 discharges the gas of value P1 in the membrane capsule 205 through the second air pipe 201. Finally, the first conduit tube 203 is filled with the gas of value P3, causing the suspended end of the first conduit tube 203 to produce a certain displacement due to deformation, and the first conduit tube 203 drives the pointer 220 to swing a certain distance. The pointer 220 is driven by the first corundum tube 203 to move to a fixed amplitude and finally indicate a scale value on the dial 221. The indicated scale value is greater than P1 but less than or equal to the maximum range on the dial 221. The suspended end of the first corundum tube 203 drives the second corundum tube 305 via the second connecting rod 315 to overcome the return spring 316 and generate a certain displacement. If the first corundum tube 203 drives the pointer 220 to finally indicate the scale value P3 on the dial 221, it indicates that the measurement accuracy of the pressure measuring instrument for different values ​​of P3 is qualified; otherwise, it is unqualified.

[0047] At this point, the pressure measuring instrument's factory inspection is complete. If the inspection passes, the pressure measuring instrument stops filling the first Bourdon tube 203 with the P3 gas through the third air pipe 204. The P1 gas in the pipeline 101 is refilled into the film capsule 205 through the branch pipe 102 and the second air pipe 201, causing the first Bourdon tube 203 to drive the pointer 220 to indicate the P1 scale value, and normal operation can be resumed. If the inspection fails, the pressure measuring instrument is removed and returned to the factory for inspection and repair.

Claims

1. A pressure measuring instrument for measuring the pressure of gas in a pipeline and detecting its own measurement accuracy, characterized in that: include: The pressure measuring component arranged in the circular shell is used to measure the air pressure in the pipeline and to perform measurement accuracy detection on the air pressure range greater than the air pressure in the pipeline under the pressure measuring state; The detection component is arranged in the round shell and is transmission-connected to the pressure measuring component. It is used to perform measurement accuracy detection on the air pressure range that is smaller than the air pressure in the pipeline by cooperating with the pressure measuring component in the pressure measuring state.

2. A pressure measuring instrument according to claim 1, characterized in that: The pressure measuring assembly includes a first Bourdon tube disposed in and coaxial with the circular shell, a second air pipe communicating with the interior of the first Bourdon tube and threadedly connected to a branch pipe on the pipeline is disposed at one end of the first Bourdon tube, the second air pipe being fixed in a first slot on the shell wall of the circular shell, a third air pipe communicating with the interior of the first Bourdon tube being disposed on the outer side of the first Bourdon tube, the third air pipe being engaged with the second slot on the shell wall of the circular shell, a film sac communicating with the second air pipe being disposed on the inner wall of the first Bourdon tube, the inner arc wall of the film sac being glued to the inner arc wall of the first Bourdon tube, and a film sac being disposed in the film sac so as to position the film between the second air pipe and the third air pipe. The open sleeve is opened and tightly attached to the inner wall of the first Bourdon tube. The suspended end of the first Bourdon tube is hinged to a first connecting rod through a first hinge pin. The end of the first connecting rod is hinged to one end of a swing arm. A fixing pin is rotatably provided in a central circular hole of the swing arm. The fixing pin is fixed to the inner wall of the circular shell. The other end of the swing arm is provided with an arc rack coaxial with the fixing pin. The arc rack meshes with a gear on a rotating shaft. The rotating shaft is rotatably provided on the inner wall of the circular shell and coaxial with the circular shell. The rotating shaft rotates in a circular hole in the middle of a dial in the circular shell. A pointer for indicating the pressure value scale on the dial is provided on the rotating shaft.

3. A pressure measuring instrument according to claim 2, characterized in that: The third tracheal side end portion of the open mouth sleeve is provided with a semi-ring sleeve for preventing the film bag from being squeezed and closed when air is inflated into the first Bourdon tube through the third trachea.

4. A pressure measuring instrument according to claim 2, characterized in that: The second air pipe is provided with a positioning ring, which is fixed to the boss at the notch of the first slot by bolts. The suspended end of the first Bourdon tube is provided with a first lug, which is hinged to the first connecting rod through a first hinge pin.

5. A pressure measuring instrument according to claim 2, characterized in that: The pointer is fixed on a circular ring on a rotating shaft, and the rotating shaft is rotatably arranged in a first rotating seat. A ring plate is arranged on the first rotating seat, and the ring plate is fixed to the inner wall of the circular shell by bolts. The fixing pin is fixed to the ring plate.

6. A pressure measuring instrument according to claim 2, characterized in that: The detection assembly includes a lock assembly disposed on the wall of the circular shell and a second waveden tube disposed within the circular shell and coaxial with the circular shell. The dimensions, specifications, and performance of the second waveden tube are identical to those of the first waveden tube. A slider is provided at one end of the second waveden tube, which cooperates with the lock assembly. The slider-side end of the second waveden tube is circumferentially spaced 180 degrees from the fixed end of the first waveden tube. The slider is slidably disposed within a guide seat on the inner wall of the circular shell about the axis of the second waveden tube. A hose is provided at the slider-side end of the second waveden tube, connecting it to the first air pipe on the wall of the circular shell. A return spring is disposed within the guide seat to maintain a circumferential spacing of 180 degrees between the slider-side end of the second waveden tube and the fixed end of the first waveden tube. The two ends of the return spring are respectively connected to the inner wall of the guide seat and the slider. A second lug is provided at the other end of the second waveden tube. The second lug is hingedly connected to one end of a second connecting rod via a second hinge pin. The other end of the second connecting rod is hingedly connected to the first lug at the end of the first waveden tube via a first hinge pin.

7. A pressure measuring instrument according to claim 6, characterized in that: The slider is provided with a first anti-slip groove that cooperates with the lock assembly.

8. A pressure measuring instrument according to claim 7, characterized in that: The lock assembly includes a screw, the screw thread is set in a threaded sleeve on the wall of the circular shell, the inner end of the screw is rotatably provided with a second rotating seat, the second rotating seat is provided with an arc plate that cooperates with the slider, the arc plate is provided with a second tooth pattern that cooperates with the first tooth pattern, the arc plate is provided with a guide hole that slides with the guide rod on the inner wall of the circular shell, and the outer end of the screw is provided with a torsion wheel.

9. The pressure measuring instrument according to claim 1, characterized in that: A first limiting ring for limiting the position of the dial is provided in the circular shell, a transparent shell cover is provided on the outer side of the dial and spaced apart from the dial, a spacer ring is provided between the shell cover and the dial, and a second limiting ring for fixing the shell cover is provided at the end of the circular shell by bolts.

10. A pressure measuring instrument according to claim 9, characterized in that: The second limiting ring is provided with a first blocking bar and a second blocking bar for shielding the first slot and the second slot respectively.

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