A leak-proof and pulse-resistant pressure gauge

Abstract

The present invention discloses an anti-leakage and anti-pulse pressure gauge, which comprises a gauge head. An instrument connecting pipe is fixedly installed on the gauge head. The bourdon tube in the gauge head is connected to the top of the instrument connecting pipe and communicates with the inner cavity of the instrument connecting pipe. The inner cavities of the bourdon tube and the instrument connecting pipe are both filled with a pressure-conducting liquid. An isolation sleeve for receiving the measured medium is arranged in the inner cavity of the instrument connecting pipe. The isolation sleeve seals the inner cavity of the instrument connecting pipe and isolates the measured medium from the pressure-conducting liquid. The isolation sleeve is made of an elastic material and deforms under the pressure of the measured medium to extrude the pressure-conducting liquid. A flow-limiting device for restricting the flow rate of the pressure-conducting liquid is installed in the inner cavity of the instrument connecting pipe. The flow-limiting device is located between the bourdon tube and the isolation sleeve, and there is a sliding seal between the flow-limiting device and the instrument connecting pipe. This solution can effectively eliminate the pulse pressure, making the instrument have excellent anti-pulse pressure performance, increasing the service life, and at the same time avoiding safety accidents caused by the fatigue burst of the elastic element of the instrument.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure measuring instruments, and particularly relates to an anti-leakage and anti-pulse pressure gauge. Background Art

[0002] Pressure gauges are widely used for pressure indication of device equipment in industries such as petroleum, chemical industry, metallurgy, military, aerospace, electric power, coal mine, medicine, printing and dyeing, etc. In recent years, the national industry has developed rapidly, and its usage has increased linearly. The existing product technologies can no longer fully meet the technical requirements of advanced equipment, with poor use effects, frequent maintenance and replacement, and frequent safety accidents.

[0003] The pressure gauges of existing technology products are mainly used on equipment with pressure and vibration. The main technical deficiencies are as follows:

[0004] 1. Anti-pulse pressure: The only method for existing technology products to solve anti-pulse pressure is to add a current-limiting device (i.e., a damper). Its disadvantages are: The damper directly flows into the measured medium, and due to the different viscosities and pressures of the measured medium, its current-limiting needs to be gradually and repeatedly adjusted to the best state during the operation of on-site equipment. The adjuster must have corresponding technology or experience, and the personal safety of the adjuster cannot be guaranteed; if there are solid particles in the measured medium, it is extremely easy to block the current-limiting hole, resulting in the instrument being unable to display the actual pressure value, which may cause equipment damage in the light case and safety accidents in the heavy case.

[0005] 2. Anti-leakage: For existing technology products, due to the poor anti-pulse pressure effect, the spring tube element in the gauge head is likely to be fatigued and damaged. When the spring tube element in the gauge head is fatigued and damaged, the existing pressure gauge structure cannot achieve rapid self-sealing, and can only let the measured medium flow out. If the measured medium is flammable, explosive, toxic, or corrosive, and the operator cannot discover and repair the leakage situation in time, it will cause serious impacts on equipment components or trigger safety accidents. Summary of the Invention

[0006] The purpose of the present invention is to solve the above problems in the existing technology, and propose an anti-leakage and anti-pulse pressure gauge, which can effectively eliminate pulse pressure, make the anti-pulse pressure performance of the instrument excellent, increase the service life, and at the same time avoid safety accidents caused by the fatigue and bursting of the elastic element of the instrument.

[0007] The technical solution of the present invention is:

[0008] An anti-leakage and anti-pulse pressure gauge, comprising a gauge head, wherein an instrument connecting pipe is fixedly installed on the gauge head, a bourdon tube in the gauge head is connected to the top of the instrument connecting pipe and communicated with the inner cavity of the instrument connecting pipe. It is characterized in that the inner cavities of the bourdon tube and the instrument connecting pipe are both filled with a pressure-conducting liquid, an isolation sleeve for receiving the measured medium is arranged in the inner cavity of the instrument connecting pipe, the isolation sleeve seals the inner cavity of the instrument connecting pipe and isolates the measured medium from the pressure-conducting liquid; the isolation sleeve is made of an elastic material and deforms under the pressure of the measured medium to extrude the pressure-conducting liquid; a flow-limiting device for restricting the flow rate of the pressure-conducting liquid is installed in the inner cavity of the instrument connecting pipe, and the flow-limiting device is located between the bourdon tube and the isolation sleeve.

[0009] Preferably, the isolation sleeve is of a tubular structure and consists of a circular tube and a corrugated tube. The outer wall of the circular tube part of the isolation sleeve is fixedly arranged on the inner wall of the inner cavity of the instrument connecting pipe. The corrugated tube part of the isolation sleeve is located in the inner cavity of the instrument connecting pipe, and the end of the corrugated tube part of the isolation sleeve is closed.

[0010] Preferably, the flow-limiting device is of a strip-shaped columnar structure, and its outer contour shape matches the inner cavity of the instrument connecting pipe; through holes for the pressure-conducting liquid to flow through are formed in the flow-limiting device, and the through holes penetrate through the flow-limiting device.

[0011] Preferably, the through holes are located at the central axis of the flow-limiting device, an annular groove coaxial with the through holes is formed in the bottom surface of the flow-limiting device, and a sealing ring is installed in the annular groove. The thickness of the sealing ring is greater than the depth of the annular groove.

[0012] Preferably, the flow-limiting device is fixed in the inner cavity of the instrument connecting pipe.

[0013] Preferably, the flow-limiting device is slidably sealed with the instrument connecting pipe. A driving mechanism for moving the flow-limiting device is arranged on the pipe wall of the instrument connecting pipe, and the driving mechanism is in transmission connection with the flow-limiting device; a positioning mechanism for restricting the position of the driving mechanism is further arranged on the outer wall of the instrument connecting pipe.

[0014] Preferably, the driving mechanism includes a circular nut and a moving ring. The circular nut and the moving ring are coaxially arranged with the instrument connecting pipe. The moving ring is sleeved on the instrument connecting pipe, the circular nut is also sleeved on the moving ring, and a thread structure adapted to the circular nut is arranged on the outer wall of the moving ring; the moving ring is fixedly connected with the flow-limiting device through a limiting rod, and an installation slot hole for restricting the position movement of the limiting rod is formed in the pipe wall of the instrument connecting pipe.

[0015] Preferably, the positioning mechanism includes a first limiting plate and a second limiting plate. Both the first limiting plate and the second limiting plate are fixedly sleeved on the pipe wall of the instrument connecting pipe. The circular nut is rotatably arranged between the first limiting plate and the second limiting plate, and two end faces of the circular nut are respectively in sliding contact with the first limiting plate and the second limiting plate.

[0016] Advantages of the present invention:

[0017] 1. The anti-leakage and anti-pulse pressure gauge provided by the present invention changes the original anti-pulse pressure technology, adds a movable and adjustable current-limiting device, effectively eliminates the pulse pressure, makes the anti-pulse pressure performance of the instrument excellent, and increases the service life;

[0018] 2. By providing a corrugated isolation sleeve, it effectively solves the problem that complex measured media enter the current-limiting device and the meter head, plays a protective role for the current-limiting device and the meter head, and separates the measured media from the pressure guiding liquid through the isolation sleeve, avoiding mutual doping and resulting in pollution. At the same time, it is also convenient for the instrument to be used for the measurement of other measured media;

[0019] 3. By adopting the technology of using the isolation sleeve to block the through hole in the current-limiting device, the isolation sleeve is closely attached to the current-limiting device to seal and block the through hole. When the instrument pressure rises to the maximum range value of the instrument, the through hole is sealed and blocked. Even if the pressure of the measured medium continues to rise, the pressure in the meter head will not rise, protecting the instrument from damage when the pressure of the measured medium exceeds the maximum range of the instrument; in addition, when the elastic element of the instrument is fatigued and burst, the isolation sleeve blocks the current-limiting device, ensuring that the measured medium will not flow out too much, avoiding large-area leakage and causing pollution and damage to equipment components, and preventing safety accidents caused by the fatigue and burst of the elastic element of the instrument;

[0020] 4. By setting a driving mechanism, the position of the current-limiting device in the instrument connecting pipe is adjusted, and thus the maximum range measured by the meter head is adjusted, and it can be adjusted according to different measured media. Description of the drawings

[0021] Figure 1 It is the front view of the anti-leakage and anti-pulse pressure gauge in Embodiment 1 of the present invention;

[0022] Figure 2 It is the internal structure schematic diagram of the anti-leakage and anti-pulse pressure gauge in Embodiment 1 of the present invention;

[0023] Figure 3 It is the sectional structure schematic diagram of the current-limiting device in Embodiment 1 of the present invention;

[0024] Figure 4 It is the structure schematic diagram of the sealing ring and the spring in Embodiment 1 of the present invention;

[0025] Figure 5Schematic diagram of the three-dimensional structure of the current-limiting device in Embodiment 1 of the present invention;

[0026] Figure 6 Schematic diagram of the structure of the driving mechanism in Embodiment 1 of the present invention;

[0027] Figure 7 Front view of the anti-leakage and anti-pulse pressure gauge in Embodiment 2 of the present invention;

[0028] Figure 8 Schematic diagram of the internal structure of the anti-leakage and anti-pulse pressure gauge in Embodiment 2 of the present invention;

[0029] Figure 9 Schematic diagram of the sectional structure of the current-limiting device in Embodiment 2 of the present invention;

[0030] Figure 10 Schematic diagram of the three-dimensional structure of the current-limiting device in Embodiment 2 of the present invention;

[0031] Figure 11 Schematic diagram of the seal ring and spring structure in Embodiment 2 of the present invention;

[0032] In the figure, 1 is the meter head; 101 is the bourdon tube;

[0033] 2 is the instrument connection pipe; 201 is the pressure guiding liquid; 202 is the installation slot hole;

[0034] 3 is the current-limiting device; 301 is the through hole; 302 is the slotted opening; 303 is the toothed plate; 304 is the annular groove; 305 is the installation hole;

[0035] 4 is the isolation sleeve;

[0036] 5 is the driving mechanism; 501 is the ratchet wheel; 502 is the connecting shaft; 503 is the round nut; 504 is the moving ring; 505 is the limiting rod;

[0037] 6 is the positioning mechanism; 601 is the pawl; 602 is the connecting rod; 603 is the hinge shaft; 604 is the first limiting plate; 605 is the second limiting plate;

[0038] 7 is the measured medium;

[0039] 8 is the seal ring;

[0040] 9 is the spring; Detailed implementation manners

[0041] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the present invention.

[0042] It should be understood that the orientation or positional relationship indicated by terms such as "horizontal, vertical, top, bottom, upper part, lower part, both sides, above", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0043] Embodiment 1

[0044] Refer to Figures 1 to 5As shown in the figure, the present invention provides a leak-proof and pulse-resistant pressure gauge, which includes a gauge head 1 and a gauge connection pipe 2 installed on the gauge head 1. The gauge connection pipe 2 is vertically arranged, and the gauge head 1 is sleeved and installed at the top of the gauge connection pipe 2. The bourdon tube 101 installed in the gauge head 1 is fixedly connected to the top of the gauge connection pipe 2 and communicates with the inner cavity of the gauge connection pipe 2. The inner cavities of both the bourdon tube 101 and the gauge connection pipe 2 are filled with a pressure-conducting liquid 201, which is a solid-particle-free liquid with extremely small changes in viscosity and expansion coefficient under temperature and pressure changes. Specifically, silicone oil, glycerol, transformer oil, etc. can be used. By changing the volume of the pressure-conducting liquid 201 in the bourdon tube 101, the shape of the bourdon tube 101 is changed, and the bourdon tube 101 drives the pointer to rotate when it deforms. It should be noted that in the pressure gauge heads in the prior art, the pointer is driven to rotate by the deformation of the bourdon tube 101, which is common knowledge in the art. Further, in Embodiment 1 of the present invention, an isolation sleeve 4 is arranged at a position near the bottom of the inner cavity of the gauge connection pipe 2 for receiving the measured medium 7. The isolation sleeve 4 is made of a material with high toughness and high elasticity, specifically a thin plate made of stainless steel or alloy steel, and the thickness is selected according to the different pressure ranges measured by the instrument. In addition, the isolation sleeve 4 extends into the inner cavity of the gauge connection pipe 2, and a part of the outer wall of the isolation sleeve 4 is fixedly bonded to the inner wall of the inner cavity of the gauge connection pipe 2 to seal the inner cavity of the gauge connection pipe 2 and prevent the pressure-conducting liquid 201 from flowing out of the gauge connection pipe 2. By introducing the measured medium 7 into the isolation sleeve 4, its pressure first acts on the isolation sleeve 4. When the isolation sleeve 4 deforms and displaces, it exerts pressure on the pressure-conducting liquid 201 in the gauge connection pipe 2, causing the pressure-conducting liquid 201 to flow towards the bourdon tube 101, and then exerting pressure on the bourdon tube 101 to cause deformation, driving the pointer on the gauge head 1 to rotate. In addition, a flow-limiting device 3 is also installed in the gauge connection pipe 2. The flow-limiting device 3 is located between the bourdon tube 101 and the isolation sleeve 4, and a sliding seal is provided between the flow-limiting device 3 and the gauge connection pipe 2. In other embodiments, the flow-limiting device 3 can also be fixed in the inner cavity of the gauge connection pipe 2 according to actual use conditions. By setting the flow-limiting device 3, the flow rate of the pressure-conducting liquid 201 is restricted. When the measured medium 7 enters the isolation sleeve 4, the isolation sleeve 4 then exerts pressure on the pressure-conducting liquid 201 below the flow-limiting device 3, causing the pressure-conducting liquid 201 below the flow-limiting device 3 to pass through the flow-limiting device 3 and come to the upper part of the flow-limiting device 3 and enter the bourdon tube 101. When the pressure-conducting liquid 201 passes through the flow-limiting device 3, due to the flow-limiting effect of the flow-limiting device 3, the flow rate of the pressure-conducting liquid 201 becomes slower, thereby reducing the pulse intensity of the pressure-conducting liquid 201 and playing a protective role for the bourdon tube 101. Through the sliding seal between the flow-limiting device 3 and the gauge connection pipe 2 before, the flow-limiting device 3 can move in the gauge connection pipe 2, adjust the position of the flow-limiting device 3 in the gauge connection pipe 2, and then adjust the distance between the flow-limiting device 3 and the isolation sleeve 4, so that when the pressure value of the gauge head 1 rises to the maximum range value, the top of the isolation sleeve 4 contacts the flow-limiting device 3;When the isolation sleeve 4 deforms until its top contacts the flow-limiting device 3, the flow-limiting device 3 is sealed and blocked, thereby blocking the flow of the pressure-conducting liquid 201. Even if the pressure of the measured medium continues to rise, the bourdon tube 101 at this time will not continue to deform due to the continuous increase in the pressure of the measured medium, protecting the instrument from damage when the pressure of the measured medium exceeds the maximum range of the instrument; and the sealed contact between the isolation sleeve 4 and the flow-limiting device 3 can also prevent the leakage of liquid from the meter head 1. If the bourdon tube 101 ruptures under pressure, the inner cavity of the instrument connection tube 2 is communicated with the external atmospheric pressure. At this time, the isolation sleeve 4 will be further deformed by the pressure of the measured medium 7. When the top of the isolation sleeve 4 contacts and seals the flow-limiting device 3, the air pressure connection between the instrument connection tube 2 and the external environment is blocked, thereby blocking the pressure-conducting liquid 201 from leaking out and also blocking the measured medium from leaking out.

[0045] Referring to Figure 2 As shown, in the specific embodiment 1 of the present invention, the isolation sleeve 4 is a tubular structure, composed of a circular tube and a corrugated tube. The lower half of the isolation sleeve 4 is a circular tube, and its outer wall is fixedly bonded to the inner wall of the bottom of the inner cavity of the instrument connection tube 2 for sealing the inner cavity of the instrument connection tube 2 to prevent the pressure-conducting liquid 201 from flowing out and the measured medium from flowing in; the upper half of the isolation sleeve 4 is a corrugated tube, and the maximum corrugation diameter of the corrugated tube part is smaller than the inner cavity size of the instrument connection tube 2, so that there is enough space between the corrugated tube part and the inner cavity of the instrument connection tube 2 when the corrugated tube part deforms; through the design of the corrugated tube structure, on the one hand, it can initially buffer the measured medium 7 entering the isolation sleeve 4. When the measured medium 7 enters the corrugated section, it is blocked by the tube wall, thereby buffering the pulse pressure; on the other hand, through the design of the corrugated tube structure, when the isolation sleeve 4 deforms under the pressure of the measured medium 7, its top can move vertically towards each other, and the corrugated tube structure changes into a cylindrical structure. This process can quickly push the pressure-conducting liquid 201 to flow, affecting the bourdon tube 101 and improving the sensitivity of the pressure gauge.

[0046] Referring to Figures 2 to 4As shown, in Specific Embodiment 1 of the present invention, the current-limiting device 3 is integrally in a strip-shaped columnar structure, and the outer contour shape of the current-limiting device 3 matches the inner cavity shape of the instrument connecting pipe 2. The surface roughness of the current-limiting device 3 is adapted to the surface roughness of the inner wall of the instrument connecting pipe 2, so that a sealed sliding can be achieved between the current-limiting device 3 and the instrument connecting pipe 2. Its sliding seal principle is the same as the sliding seal between the piston and the cylinder in an automobile engine. In addition, a through-hole 301 is provided in the current-limiting device 3. The aperture of the through-hole 301 is smaller than the diameter of the current-limiting device 3, and the through-hole 301 penetrates through the current-limiting device 3, so that the pressure guiding liquid 201 can flow through the through-hole 301. Since the outer wall of the current-limiting device 3 and the inner wall of the instrument connecting pipe 2 are in sliding seal, the pressure guiding liquid 201 will not flow between the current-limiting device 3 and the instrument connecting pipe 2. Therefore, the pressure guiding liquid 201 can only pass through the through-hole 301. Also, because the diameter of the through-hole 301 is smaller, smaller than the maximum outer diameter of the current-limiting device 3, the diameter of the through-hole 301 is also smaller than the inner diameter of the instrument connecting pipe 2. When the pressure guiding liquid 201 is pressured to pass through the through-hole 301, due to the small aperture of the through-hole 301, it has a buffering effect on the pressure guiding liquid 201, so that the pulse pressure of the pressure guiding liquid 201 decreases after passing through the current-limiting device 3, reducing the damage caused by the pulse pressure to the bourdon tube 101. Additionally, the through-hole 301 is also located above the center position of the top surface of the isolation sleeve 4, so that after the isolation sleeve 4 contacts the bottom surface of the current-limiting device 3, the isolation sleeve 4 can completely cover the through-hole 301 and play a good sealing role to block the flow of the pressure guiding liquid 201.

[0047] Referring to Figures 3 to 5 As shown, in Specific Embodiment 1 of the present invention, the above-mentioned through-hole 301 is located at the central axis position of the current-limiting device 3 and is vertically arranged. A circular groove 304 is provided on the bottom end surface of the current-limiting device 3. The circular groove 304 is coaxially arranged with the through-hole 301, and the inner diameter of the circular groove 304 is larger than the diameter of the through-hole 301, and the outer diameter of the circular groove 304 is smaller than the diameter of the current-limiting device 3. A sealing ring 8 is installed in the circular groove 304. The width of the sealing ring 8 is adapted to the groove width of the circular groove 304. In addition, the thickness of the sealing ring 8 is larger than the groove depth of the circular groove 304. When the top surface of the sealing ring 8 is in close contact with the inner top surface of the circular groove 304, at this time, the bottom surface of the sealing ring 8 protrudes from the circular groove 304 and extends out of the bottom end surface of the current-limiting device 3, forming a stepped structure with the bottom surface of the current-limiting device 3. So that when the isolation sleeve 4 contacts the bottom surface of the current-limiting device 3, the sealing ring 8 can contact and squeeze the isolation sleeve 4, further playing a sealing effect to prevent the pressure guiding liquid 201 from flowing out of the through-hole 301.

[0048] Furthermore, referring to Figure 5As shown, in Specific Embodiment 1 of the present invention, the above-mentioned sealing ring 8 is vertically and slidably installed in the annular groove 304 and can move along the depth direction of the annular groove 304. A plurality of mounting holes 305 are formed in the inner top surface of the annular groove 304. The plurality of mounting holes 305 are arranged in a circumferential and evenly distributed manner around the central axis of the annular groove 304. And a vertically arranged spring 9 is installed in each mounting hole 305. The two ends of the spring 9 are respectively fixed on the top surface of the sealing ring 8 and the inner top surface of the mounting hole 305. By providing the spring 9, on the one hand, when the isolation sleeve 4 is in contact with the sealing ring 8, through the elastic buffer of the spring 9, part of the pulse pressure can be reduced. On the other hand, if the isolation sleeve 4 seals the bottom surface of the flow limiting device 3 for a long time, it is easy to occur the situation of extrusion and adhesion. At this time, through the self-resetting elastic force of the spring 9, the isolation sleeve 4 is separated from the flow limiting device 3, so that the pressure guiding liquid 201 can flow again.

[0049] Referring to Figure 1 As shown, in Specific Embodiment 1 of the present invention, a driving mechanism 5 is provided on the pipe wall of the instrument connecting pipe 2. The driving mechanism 5 penetrates the pipe wall of the instrument connecting pipe 2 and is connected and transmitted with the flow limiting device 3. The flow limiting device 3 is moved through the driving mechanism 5, so that the flow limiting device 3 seals and slides in the instrument connecting pipe 2, thereby changing the distance between the flow limiting device 3 and the isolation sleeve 4, and realizing the adjustment of the maximum range of the meter head 1. A positioning mechanism 6 is also provided on the outer wall of the instrument connecting pipe 2. The positioning mechanism 6 is adapted to the driving mechanism 5, and the position of the driving mechanism 5 is restricted through the positioning mechanism 6 to prevent the driving mechanism 5 from detaching from the instrument connecting pipe 2.

[0050] Further, referring to Figure 2 and Figure 6As shown in the figure, in the first specific embodiment of the present invention, the driving mechanism 5 includes a circular nut 503 and a moving ring 504. The circular nut 503 and the moving ring 504 are both coaxially arranged with the instrument connecting pipe 2. Among them, the moving ring 504 is sleeved on the instrument connecting pipe 2, and the inner diameter of the moving ring 504 is slightly larger than the maximum outer diameter of the instrument connecting pipe 2; the circular nut 503 is sleeved on the moving ring 504, and a thread mechanism adapted to the circular nut 503 is provided on the outer wall of the moving ring 504. Through the mutually adapted thread structure, the circular nut 503 and the moving ring 504 are adapted and engaged, and can be engaged and driven; in addition, the moving ring 504 is fixedly connected to the flow limiting device 3 through a limiting rod 505, and the thickness of the moving ring 504 is the same as the height of the limiting rod 505. When the circular nut 503 rotates to drive the moving ring 504 to move, the moving ring 504 drives the limiting rod 505 to move, thereby adjusting the position of the flow limiting device 3; additionally, an installation slot hole 202 for the limiting rod 505 to pass through is opened on the pipe wall of the instrument connecting pipe 2. The shape and size of the installation slot hole 202 are smaller than the diameter and height of the flow limiting device 3, so that the outer wall of the flow limiting device 3 can completely cover the installation slot hole 202 to prevent the pressure guiding liquid 201 from flowing out of the installation slot hole 202; the limiting rod 505 passes through the installation slot hole 202, one end of which is fixedly connected to the outer wall of the flow limiting device 3, and the other end is fixedly connected to the inner ring wall of the moving ring 504, and the width of the limiting rod 505 matches the width of the installation slot hole 202. The height of the installation slot hole 202 is greater than the height of the limiting rod 505; by adapting the width of the limiting rod 505 to the width of the installation slot hole 202, the limiting rod 505 cannot rotate axially. Therefore, when the circular nut 503 rotates, the circular nut 503 and the moving ring 504 are engaged and driven. Under the action of the limiting rod 505, the moving ring 504 will not rotate axially. Since the moving ring 504 will not rotate, when the circular nut 503 rotates, the moving ring 504 can only generate a vertical displacement under the action of the limiting rod 505, thereby causing the limiting rod 505 to move vertically along the installation slot hole 202 to drive the movement of the flow limiting device 3, realizing the control and adjustment of the position of the flow limiting device 3; it should also be noted that since the circular nut 503 is restricted by the positioning mechanism 6 and can only rotate axially, when the circular nut 503 and the moving ring 504 are engaged and driven, the moving ring 504 will move vertically under the action of the limiting rod 505; and the height of the circular nut 503 is the same as the height of the installation slot hole 202 to achieve the maximum displacement distance of the moving ring 504 and the limiting rod 505.

[0051] Furthermore, referring to Figure 2As shown, in the specific embodiment 1 of the present invention, the positioning mechanism 6 includes a limit plate 1 604 and a limit plate 2 605, and the limit plate 1 604 and the limit plate 2 605 are both annular plate structures, and the limit plate 1 604 and the limit plate 2 605 are fixedly sleeved on the pipe wall of the instrument pipe 2, and are respectively located at the upper and lower end faces of the circular nut 503, and the circular nut 503 is rotatably set between the limit plate 1 604 and the limit plate 2 605, and its upper and lower end faces are respectively in sliding contact with the limit plate 1 604 and the limit plate 2 605, so that the circular nut 503 can rotate; by setting the limit plate Plate 1 604 and limit plate 2 605 clamp the circular nut 503 to keep the position of the circular nut 503 relatively stable, thereby preventing the circular nut 503 from falling off the instrument pipe 2 and affecting the use of the device. It should also be noted that in specific embodiment 1, a pressure mark is engraved on the edge of the end face of the circular nut 503. This pressure mark is obtained based on the conclusions of multiple experiments, so that after rotating the circular nut 503 to adjust the position of the current limiting device 3, the operator can judge the maximum pressure range that the meter head 1 can measure at this time by observing the mark on the circular nut 503.

[0052] Example 2

[0053] The structures and connection relationships of Example 1 and Example 2 are the same, except that:

[0054] Reference Figure 7 As shown, in specific embodiment 2 of the present invention, a driving mechanism 5 is provided on the pipe wall of the instrument pipe 2, the driving mechanism 5 passes through the pipe wall of the instrument pipe 2, and is connected to the current limiting device 3 for transmission. The current limiting device 3 is moved by the driving mechanism 5, so that the current limiting device 3 is sealed and slides in the instrument pipe 2, thereby changing the distance between the current limiting device 3 and the isolation sleeve 4, and realizing the adjustment of the maximum range of the meter head 1; a positioning mechanism 6 is also provided on the outer wall of the instrument pipe 2, the positioning mechanism 6 is adapted and engaged with the driving mechanism 5, and the driving mechanism 5 is fixed and locked by the positioning mechanism 6; when the measured medium 7 enters the isolation sleeve 4 and squeezes the pressure-guiding liquid 201, the pressure-guiding liquid 201 is pressurized and flows toward the current limiting device 3, and a certain pulse pressure is also generated on the current limiting device 3, so that the current limiting device 3 is driven to move. After the positioning mechanism 6 and the driving mechanism 5 are adapted and locked, transmission cannot be carried out between the driving mechanism 5 and the current limiting device 3, thereby locking the position of the current limiting device 3.

[0055] Further, refer to Figure 8 and Figure 10As shown in the figure, in the second specific embodiment of the present invention, the driving mechanism 5 includes a ratchet wheel 501 and a connecting shaft 502. An installation slot hole 202 for installing the ratchet wheel 501 is opened on the pipe wall of the instrument connection pipe 2. The connecting shaft 502 is horizontally arranged in the installation slot hole 202, and its two ends are respectively fixed on the inner walls on both sides of the installation slot hole 202. The ratchet wheel 501 is rotatably installed on the connecting shaft 502, and the left and right ends of the ratchet wheel 501 respectively extend beyond the installation slot hole 202. One end of it extends into the interior of the instrument connection pipe 2 and is in adaptive contact with the limiting device 3. The other end of the ratchet wheel 501 extends into the pipe wall of the instrument connection pipe 2, facilitating manual contact and rotation by the operator. In addition, a slot 302 corresponding to the position of the installation slot hole 202 is opened on the side wall of the flow limiting device 3. The slot 302 is a vertically strip-shaped groove. The length and width dimensions of the slot 302 are larger than those of the installation slot hole 202, and the width of the slot 302 is smaller than the diameter of the flow limiting device 3. The two ends of the slot 302 do not penetrate through the two ends of the flow limiting device 3. Through the sliding seal between the upper and lower ends of the flow limiting device 3 and the instrument connection pipe 2, it is avoided that the pressure guiding liquid 201 flows out from the slot 302. Additionally, a toothed plate 303 adapted to the ratchet wheel 501 is fixed on the inner wall of the slot 302. By rotating the ratchet wheel 501, the toothed plate 303 is driven to move, thereby realizing the sealed sliding of the flow limiting device 3 in the instrument connection pipe 2. It should also be explained that in the specific embodiment, a pressure mark is engraved at the edge position of the end face of the ratchet wheel 501. This pressure mark is obtained based on the conclusions of multiple experiments, so that after rotating the ratchet wheel 501 to adjust the position of the flow limiting device 3, the operator can judge the maximum pressure range that the meter head 1 can measure at this time by observing the mark on the ratchet wheel 501.

[0056] Further, as shown in Figure 8 the figure, in the second specific embodiment of the present invention, the positioning mechanism 6 includes a pawl 601 and a connecting rod 602. The connecting rod 602 is vertically inclined, and its axis direction is perpendicular to the axis direction of the connecting shaft 502. In addition, one end of the connecting rod 602 is rotatably installed on the outer wall of the instrument connection pipe 2 through a hinge shaft 603, and the hinge shaft 603 is located directly above the installation slot hole 202, so that the connecting rod 602 is located above the driving mechanism 5 and rotates around the hinge shaft 603. In addition, the pawl 601 has a hook-shaped structure, one end of which is fixed on the connecting rod 602, and the other end of the pawl 601 is adaptively clamped between the teeth of the ratchet wheel 501. By clamping the pawl 601 onto the ratchet wheel 501, the ratchet wheel 501 is limited and fixed. It should be noted that when the pawl 601 is clamped onto the ratchet wheel 501, the concave surface of the pawl 601 faces the ratchet wheel 501 at this time, and the end of the pawl 601 is clamped on the lower half of the ratchet wheel 501. As shown in Figure 2As shown in the figure, after adjusting the position of the current-limiting device 3 in the instrument connection pipe 2, the measured medium 7 is introduced into the isolation sleeve 4. At this time, the pressure guiding liquid 201 will be pulsed and squeezed by the isolation sleeve 4 and start to move upward. When the pressure guiding liquid 201 passes through the through hole 301 on the current-limiting device 3, since the current-limiting device 3 blocks and slows down the pressure guiding liquid 201, the current-limiting device 3 will be subjected to a vertically upward extrusion thrust from the pressure guiding liquid 201. At this time, the current-limiting device 3 has a tendency to move upward. After the current-limiting device 3 shows a tendency to move upward, the force will be transmitted to the ratchet wheel 501 through the toothed plate 303. At this time, the ratchet wheel 501 will have a clockwise rotation tendency. By engaging and hooking the pawl 601 on the lower half of the ratchet wheel 501, the rotation of the ratchet wheel 501 can be effectively prevented, so that the current-limiting device 3 can be effectively prevented from moving and displacing in the instrument connection pipe 2, which may affect the maximum range of the meter head 1 and the measurement process of the measured medium 7.

[0057] The working process and principle of the present invention:

[0058] Before use, according to the pressure range to be measured of the measured medium 7, the measurement personnel manually control the driving mechanism 5 to adjust the position of the current-limiting device 3 in the instrument connection pipe 2. After the position of the current-limiting device 3 is adjusted, the measurement personnel then remove the force applied to the driving mechanism 5 and fix the driving mechanism 5 to prevent it from moving; subsequently, the bottom of the instrument connection pipe 2 is connected to the pipe through which the measured medium 7 flows. After the connection is completed, the measured medium 7 enters the isolation sleeve 4. Through the pulsed pressure generated by the measured medium 7 on the isolation sleeve 4, the isolation sleeve 4 deforms, the volume of the isolation sleeve 4 increases and it approaches the current-limiting device 3. The isolation sleeve 4 squeezes the pressure guiding liquid 201 in the instrument connection pipe 2. The pressure guiding liquid 201 is pressed and then comes to the top of the instrument connection pipe 2 through the current-limiting device 3 and is squeezed into the bourdon tube 101. The bourdon tube 101 is deformed by the force and drives the pointer on the meter head 1 to rotate.

[0059] If the bourdon tube 101 bursts due to fatigue failure, the pressure guiding liquid 201 will flow out from the rupture of the bourdon tube 101. At this time, the internal air pressure of the instrument connection pipe 2 is communicated with the external air pressure. The isolation sleeve 4 deforms rapidly under the pulsed pressure of the measured medium and approaches the current-limiting device 3 until the through hole 301 on the current-limiting device 3 is sealed to prevent the continuous outflow of the pressure guiding liquid 201 and avoid further damage to the equipment.

[0060] The above description of the specific embodiments of the present invention is for illustrative and exemplifying purposes. These descriptions are not intended to limit the present invention to the precise forms disclosed, and it is obvious that, according to the above description, numerous changes and variations can be made. The purpose of selecting and describing the embodiments is to explain the specific principles and practical applications of the present invention, so that those skilled in the art can implement and utilize various different embodiments of the present invention, as well as various different selections and changes. The scope of the present invention is intended to be defined by the claims and their equivalents.

Claims

1. A leak-proof and pulse-resistant pressure gauge, comprising a gauge head (1), wherein an instrument connection pipe (2) is fixedly installed on the gauge head (1), a bourdon tube (101) in the gauge head (1) is connected to the top of the instrument connection pipe (2) and communicates with the inner cavity of the instrument connection pipe (2), and is characterized in that, The interiors of the bourdon tube (101) and the instrument connection tube (2) are both filled with a pressure-conducting liquid (201). An isolation sleeve (4) for receiving the measured medium (7) is provided in the interior of the instrument connection tube (2). The isolation sleeve (4) seals the interior of the instrument connection tube (2) and isolates the measured medium (7) from the pressure-conducting liquid (201). The isolation sleeve (4) is made of an elastic material and deforms under the pressure of the measured medium (7) to extrude the pressure-conducting liquid (201). A flow-limiting device (3) for restricting the flow rate of the pressure-conducting liquid (201) is installed in the interior of the instrument connection tube (2). The flow-limiting device (3) is located between the bourdon tube (101) and the isolation sleeve (4). The flow-limiting device (3) is in sliding seal with the instrument connection tube (2). A driving mechanism (5) for moving the flow-limiting device (3) is provided on the tube wall of the instrument connection tube (2). The driving mechanism (5) is in transmission connection with the flow-limiting device (3). A positioning mechanism (6) for restricting the position of the driving mechanism (5) is further provided on the outer wall of the instrument connection tube (2). The driving mechanism (5) includes a round nut (503) and a moving ring (504). The round nut (503) and the moving ring (504) are coaxially arranged with the instrument connection tube (2). The moving ring (504) is sleeved on the instrument connection tube (2). The round nut (503) is also sleeved on the moving ring (504), and a thread structure adapted to the round nut (503) is provided on the outer wall of the moving ring (504). The moving ring (504) is fixedly connected to the flow-limiting device (3) through a limiting rod (505). An installation slot hole (202) for restricting the position movement of the limiting rod (505) is provided in the tube wall of the instrument connection tube (2).

2. The anti-leakage and anti-pulse pressure gauge according to claim 1, characterized in that, The isolation sleeve (4) is of a tubular structure and is composed of a round tube and a corrugated tube. The outer wall of the round tube part of the isolation sleeve (4) is fixedly provided on the inner wall of the interior of the instrument connection tube (2). The corrugated tube part of the isolation sleeve (4) is located in the interior of the instrument connection tube (2), and the end of the corrugated tube part of the isolation sleeve (4) is closed.

3. The anti-leakage and anti-pulse pressure gauge according to claim 1, characterized in that, The flow-limiting device (3) is of a strip-shaped columnar structure, and its outer contour shape matches the interior of the instrument connection tube (2). A through hole (301) for the pressure-conducting liquid (201) to flow through is provided on the flow-limiting device (3). The through hole (301) penetrates the flow-limiting device (3).

4. The anti-leakage and anti-pulse pressure gauge according to claim 3, characterized in that, The through hole (301) is located at the central axis of the flow-limiting device (3). An annular groove (304) coaxially arranged with the through hole (301) is provided on the bottom surface of the flow-limiting device (3). A sealing ring (8) is installed in the annular groove (304), and the height of the sealing ring (8) is greater than the depth of the annular groove (304).

5. The anti-leakage and anti-pulse pressure gauge according to claim 1, wherein, The flow-limiting device (3) is fixed in the interior of the instrument connection tube (2).

6. The anti-leakage and anti-pulse pressure gauge according to claim 5, wherein, The positioning mechanism (6) includes a first limiting plate (604) and a second limiting plate (605). The first limiting plate (604) and the second limiting plate (605) are both fixedly sleeved on the pipe wall of the instrument connection pipe (2). The round nut (503) is rotatably arranged between the first limiting plate (604) and the second limiting plate (605), and the two end faces of the round nut (503) are respectively in sliding contact with the first limiting plate (604) and the second limiting plate (605).

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