A high-precision ultrasonic pipeline thickness measuring device and its use method

Abstract

The invention discloses a high-precision ultrasonic pipeline thickness measuring device and a use method thereof, belonging to the technical field of ultrasonic thickness measuring. The steps of coating a coupling agent and installing a probe are swapped, the probe is installed first, and then the coupling agent is coated, and a pre-detection probe assembly is used to pre-detect surface defects at pipeline detection points. Only when the defects on the pipeline measuring surface are fully polished, can the shaping fitting ring and the pipe wall produce a good fitting state, and a good negative pressure state can be formed between the negative pressure detection air film and the pipe wall measuring surface. The pre-detection probe assembly is stably adsorbed on the pipeline measuring surface through the internal and external pressure difference of the negative pressure detection air film, so that the operator can judge whether the defects on the pipe wall measuring surface are well handled through the adsorption effect of the probe on the pipe wall, and the coupling agent is filled only after the defects are well handled. In this way, the measurement accuracy is greatly improved, and the waste of secondary filling of the coupling agent is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic thickness measurement, and more specifically to a high-precision ultrasonic pipeline thickness measurement device and a use method thereof. Background Art

[0002] Ultrasonic thickness measurement is used to measure thickness. When the ultrasonic pulse emitted by the probe passes through the object to be measured and reaches the material interface, the pulse is reflected back to the probe. The thickness of the material to be measured is determined by accurately measuring the time it takes for the ultrasonic wave to propagate in the material. This principle can be used to measure various materials that can allow ultrasonic waves to propagate at a constant speed inside them.

[0003] The thickness gauge designed according to this principle can accurately measure various plates and various processed parts. It can also monitor various pipelines and pressure vessels in production equipment to monitor their thinning degree after corrosion during use. It can be widely used in various fields such as petroleum, chemical industry, metallurgy, shipbuilding, aviation, aerospace, etc.

[0004] In order to ensure that the ultrasonic wave can effectively penetrate the workpiece to achieve the purpose of detection, a special coupling agent is needed to exclude the air between the probe and the object to be measured. In the actual measurement process, after long-term use, the surface roughness of the pipeline is too large, resulting in poor coupling effect between the probe and the contact surface, low reflected echo, or even no echo signal can be received. For in-service equipment and pipelines with surface rust and extremely poor coupling effect, the surface can be treated by sanding, grinding, filing and other methods to reduce the roughness. At the same time, the oxide and paint layer can also be removed to reveal the metallic luster, so that the probe and the object to be inspected can achieve a good coupling effect through the coupling agent. However, in the actual processing process, there is a problem of inadequate treatment of the rough surface of the pipeline. At this time, if the coupling agent is directly coated on the measuring surface and the thickness of the pipeline is measured by the ultrasonic thickness measuring device probe on the measuring surface, it will inevitably affect the measurement accuracy. At this time, if the coupling agent coated on the measuring surface is wiped off and then re-polished, it will not only reduce the work efficiency, but also cause waste of coupling agent. Summary of the invention

[0005] 1. Technical issues to be solved

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide a high-precision ultrasonic pipeline thickness measuring device and a method for using the same. The surface defects at the pipeline detection point are pre-detected by a pre-detection probe assembly composed of a band control terminal, a probe body, a pressure spring, a sealing sheet, a negative pressure detection air film, a defoaming semipermeable membrane and a shaping fitting ring. Only when the defects on the pipeline measuring surface are fully polished, the shaping fitting ring can form a good fitting state with the pipe wall without any gap between them. In this way, a good negative pressure state can be formed between the negative pressure detection air film and the pipe wall measuring surface. The pre-detection probe assembly is stably adsorbed on the pipeline measuring surface by the internal and external pressure difference of the negative pressure detection air film. Then, the operator injects the coupling agent into the front end space in the negative pressure detection air film separated by the defoaming semipermeable membrane through the filling tube. Pre-detection of surface defects at the measuring surface of the pipeline. Only when the surface defects are completely processed can the pre-detection probe assembly be adsorbed thereon. Only when the pre-detection probe assembly can be adsorbed on the pipeline detection point, the coupling agent is filled between the pre-detection probe assembly and the pipe wall measuring surface, and the coupling agent is wrapped in the negative pressure detection air film, so that there will be no coupling agent dripping during the process of multi-point thickness measurement of the pipe wall along a certain direction using the continuous measurement method, which is convenient for subsequent cleaning. The steps of applying the coupling agent and installing the probe are reversed. The probe is installed first, and then the coupling agent is applied. It is convenient for the operator to judge whether the defects on the measuring surface of the pipe wall are well processed by the adsorption effect of the probe on the pipe wall. Only after the processing is good, the coupling agent is filled. In this way, the measurement accuracy is greatly improved and the waste of secondary filling of the coupling agent is avoided.

[0007] 2. Technical solution

[0008] To solve the above problems, the present invention adopts the following technical solutions.

[0009] A high-precision ultrasonic pipeline thickness measuring device and a use method thereof, comprising a thickness measuring terminal, the thickness measuring terminal is electrically connected to a band control terminal through a data transmission line, a probe body is arranged on the front side of the band control terminal, a pressure spring is electrically connected between the band control terminal and the probe body, a sealing sheet is clamped on the outer end wall of the band control terminal, a negative pressure detection air film is fixedly connected to the front end of the sealing sheet, a defoaming semipermeable membrane is clamped between the probe body and the negative pressure detection air film, the pressure spring is located in a closed space formed by the sealing sheet, the negative pressure detection air film and the defoaming semipermeable membrane, a pair of mounting holes are opened on the outer end wall of the negative pressure detection air film, a stuffing tube and a negative pressure tube are clamped in the pair of mounting holes, respectively, the stuffing tube and the negative pressure tube are respectively connected to the front and rear independent spaces in the negative pressure detection air film separated by the defoaming semipermeable membrane, the stuffing tube is externally connected to a tank storing a coupling agent, and the negative pressure tube is externally connected to an air pump.

[0010] Furthermore, a shaping fitting ring is fixedly connected to the front end of the negative pressure detection air membrane, and the shaping fitting ring enables the negative pressure detection air membrane to better fit with the pipe wall.

[0011] Furthermore, a plurality of metal wire rings are filled in the shaping fitting ring, and the shaping effect of the metal wire rings on the shaping fitting ring is improved to improve the fitting effect of the shaping fitting ring on the pipe wall of the pipe with different curvature diameters.

[0012] Furthermore, the negative pressure detection air film and the shaping fitting ring are made of high-temperature resistant rubber material, so that when the pipeline to be tested is in service and high-temperature liquid flows inside it, the negative pressure detection air film and the shaping fitting ring will not undergo high-temperature deformation, the shaping fitting ring can still maintain a good fit with the pipe wall, and the negative pressure detection air film can still maintain a good negative pressure state.

[0013] Furthermore, the band control terminal can control the band emitted by the probe body through its internal control circuit. During the production, manufacturing and transportation of the coupling agent, bubbles may be mixed in it. These bubbles are filled into the pre-detection probe assembly together with the coupling agent and remain in a thin film formed between the probe body and the measuring surface of the pipe wall, attenuating the energy of the thickness measuring sound wave emitted by the probe body and causing distortion of the measurement data. The band control terminal is activated by the thickness measuring terminal to adjust the band emitted by the probe body, convert the measurement band into the defoaming band, and eliminate the bubbles mixed in the filled coupling agent. The ultrasonic vibration is transmitted to the coupling agent, and cavitation is generated in the coupling agent. Since the cavitation generates impact force, the bubbles mixed in the coupling agent can be crushed and separated. At the same time, during the ultrasonic defoaming process, the negative pressure operation in the pre-detection probe assembly does not stop, so that the bubbles separated from the coupling agent can smoothly pass through the defoaming semipermeable membrane and finally be sucked out of the probe through the negative pressure tube, thereby accelerating the bubble suction speed and improving the measurement speed while ensuring the measurement accuracy.

[0014] Furthermore, the contact pressure between the probe body and the pipe wall when the pressure spring is in a fully compressed state is 2kg. Industrial ultrasonic testing uses pulse waves with a certain bandwidth, so the influence of sound energy attenuation and multiple reflection interference should be mainly considered. Experiments have shown that the coupling layer should be as thin as possible while meeting the detection sensitivity requirements. This is also the reason why the contact pressure of the probe on the detection surface is required to reach 1.5 to 2.5kg during contact flaw detection. The contact pressure between the probe body and the pipe wall reaches 2kg through the compression of the pressure spring.

[0015] Furthermore, the coupling agent is doped with photocurable resin. After the detection operation is completed, the coupling agent filled in the pre-detection probe assembly is irradiated with ultraviolet light, and the photocurable resin filled in the coupling agent will solidify synchronously with the coupling agent, so that the solidified coupling agent can be quickly removed from the tube wall and collected, thereby improving the cleaning efficiency.

[0016] Furthermore, the photocurable resin is a water-based resin, which contains a large number of hydrophilic groups or hydrophilic segments and can be emulsified, dispersed or dissolved in water. Combined with the above-mentioned curing and collection, the coupling agent can be recycled and reused.

[0017] Furthermore, the maximum stretching length of the negative pressure detection air film is less than the stretching limit of the pressure spring. The pressure spring is protected by the negative pressure detection air film to avoid the possibility of excessive stretching of the pre-detection probe assembly during transportation and use, thereby losing the elastic squeezing effect on the pipe wall.

[0018] Furthermore, a method for using a high-precision ultrasonic pipe thickness measuring device comprises the following steps:

[0019] S1. Grinding the pipe wall: Grinding the defects on the measuring surface of the pipe to be tested;

[0020] S2. Place the probe: Align the probe body with the polished measuring surface, press the band control terminal shell to drive the pressure spring to fully compress, and the negative pressure detection air film will fit the outer wall of the pipeline synchronously;

[0021] S3. Pre-detection: Connect the negative pressure tube to a micro air pump, and use the micro air pump to extract the gas in the negative pressure detection air film. At this time, only when the defects on the measuring surface of the pipeline are fully polished, the negative pressure detection air film can be stably adsorbed on the measuring surface of the pipe wall. If stable adsorption cannot occur, continue with the polishing process of step S1;

[0022] S4. Filling coupling agent: connect the packing tube to the coupling agent storage tank, and inject the coupling agent into the front space of the negative pressure detection air film separated by the defoaming semipermeable membrane;

[0023] S5. Measure the pipe wall: Use the continuous measurement method to measure the thickness of the pipe wall at multiple points along a certain direction and take the average value of the data.

[0024] 3. Beneficial effects

[0025] Compared with the prior art, the advantages of the present invention are:

[0026] (1) This solution swaps the steps of applying the coupling agent and installing the probe. The probe is installed first, and then the coupling agent is applied. The surface defects at the pipeline detection point are pre-detected using the pre-detection probe assembly. Only when the defects on the pipeline measuring surface are fully polished can the shaping fitting ring and the pipe wall form a good fit without any gap between them. In this way, a good negative pressure state can be formed between the negative pressure detection air film and the pipe wall measuring surface. The pre-detection probe assembly is stably adsorbed on the pipeline measuring surface through the internal and external pressure difference of the negative pressure detection air film, which makes it convenient for operators to judge whether the defects on the pipe wall measuring surface are well handled by the adsorption effect of the probe on the pipe wall. Only after they are well handled, the coupling agent is filled. In this way, the measurement accuracy is greatly improved and the waste of secondary filling of the coupling agent is avoided.

[0027] (2) The front end of the negative pressure detection air film is fixedly connected with a shaping fitting ring, and the shaping fitting ring enables the negative pressure detection air film to better fit the pipe wall.

[0028] (3) The shaping fitting ring is filled with a plurality of metal wire rings, and the shaping effect of the shaping fitting ring is improved by the metal wire rings on the pipe wall of the pipe with different curvatures and diameters.

[0029] (4) The negative pressure detection air film and the shaping fitting ring are made of high temperature resistant rubber material so that when the pipeline to be tested is in service and high temperature liquid flows inside it, the negative pressure detection air film and the shaping fitting ring will not be deformed by high temperature, the shaping fitting ring can still maintain a good fit with the pipe wall, and the negative pressure detection air film can still maintain a good negative pressure state.

[0030] (5) The band control terminal can control the band emitted by the probe body through its internal control circuit. During the production, manufacturing and transportation of the coupling agent, bubbles may be mixed in it. These bubbles are filled into the pre-detection probe assembly together with the coupling agent and remain in a thin film formed between the probe body and the measuring surface of the pipe wall, attenuating the energy of the thickness measurement sound wave emitted by the probe body and causing distortion of the measurement data. The band control terminal is activated by the thickness measurement terminal to adjust the band emitted by the probe body, converting the measurement band into the defoaming band, and eliminating the bubbles mixed in the filled coupling agent. The ultrasonic vibration is transmitted to the coupling agent, and cavitation is generated in the coupling agent. Since the cavitation generates impact force, the bubbles mixed in the coupling agent can be crushed and separated. At the same time, during the ultrasonic defoaming process, the negative pressure operation in the pre-detection probe assembly does not stop, so that the bubbles separated from the coupling agent can pass through the defoaming semipermeable membrane smoothly and finally be sucked out of the probe through the negative pressure tube, thereby accelerating the bubble suction speed. Under the premise of ensuring measurement accuracy, the measurement speed is improved.

[0031] (6) The contact pressure between the probe body and the pipe wall when the pressure spring is fully compressed is 2 kg. Industrial ultrasonic testing uses pulse waves with a certain bandwidth, so the main considerations are the attenuation of sound energy and the influence of multiple reflection interference. Experiments have shown that the coupling layer should be as thin as possible while meeting the requirements of detection sensitivity. This is also the reason why the contact pressure of the probe on the detection surface is required to reach 1.5 to 2.5 kg during contact flaw detection. The contact pressure between the probe body and the pipe wall reaches 2 kg by compressing the pressure spring.

[0032] (7) The coupling agent is doped with a photocurable resin. After the detection operation is completed, the coupling agent filled in the pre-detection probe assembly is irradiated with ultraviolet light, and the photocurable resin filled in the coupling agent will solidify simultaneously with the coupling agent, so that the solidified coupling agent can be quickly removed from the tube wall and collected, thereby improving the cleaning efficiency.

[0033] (8) Photocurable resin is a water-based resin. It contains a large number of hydrophilic groups or hydrophilic segments and can be emulsified, dispersed or dissolved in water. Combined with the above-mentioned solidification collection, the coupling agent can be recycled and reused.

[0034] (9) The maximum stretching length of the negative pressure detection air film is less than the stretching limit of the pressure spring. The pressure spring is protected by the negative pressure detection air film to avoid the possibility of excessive stretching of the pre-detection probe assembly during transportation and use, thereby preventing the pre-detection probe assembly from losing its elastic squeezing effect on the pipe wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention as a whole uses a state diagram on the pipeline to be tested;

[0036] Figure 2 It is an overall partial cross-sectional view of the present invention;

[0037] Figure 3 for Figure 2 A schematic diagram of the structure at A;

[0038] Figure 4 for Figure 2 The process diagram of the coupling agent at A during solidification and collection;

[0039] Figure 5 It is a comparison diagram of the fitting relationship between the pipe to be tested and the shaping fitting ring before and after polishing of the present invention;

[0040] Figure 6 This is a state diagram of the coupling agent of the present invention before partial defoaming;

[0041] Figure 7 This is a diagram of the coupling agent of the present invention after partial defoaming;

[0042] Figure 8This is a diagram showing the distribution state of the device on the pipeline when the continuous measurement method is used to measure the thickness of the pipeline to be measured in the present invention;

[0043] Fig. 9 It is a flow chart of the use of the present invention;

[0044] Fig.10 This is a diagram of the method of use of the present invention.

[0045] Description of the numbers in the figure:

[0046] 1. Thickness measuring terminal; 201. Band control terminal; 202. Probe body; 203. Pressure spring; 3. Sealing piece; 4. Negative pressure detection air film; 401. Filling tube; 402. Negative pressure tube; 403. Shaping fitting ring; 404. Semipermeable membrane for defoaming. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0048] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are 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 position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0049] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] Embodiment 1:

[0051] See also Figure 1-3A high-precision ultrasonic pipeline thickness measuring device and a method for using the same include a thickness measuring terminal 1, the thickness measuring terminal 1 is electrically connected to a band control terminal 201 through a data transmission line, a probe body 202 is provided on the front side of the band control terminal 201, a pressure spring 203 is electrically connected between the band control terminal 201 and the probe body 202, a sealing sheet 3 is clamped on the outer end wall of the band control terminal 201, a negative pressure detection air film 4 is fixedly connected to the front end of the sealing sheet 3, and a negative pressure detection air film 4 is clamped between the probe body 202 and the negative pressure detection air film 4. The semipermeable membrane 404 for defoaming and the pressure spring 203 are located in the enclosed space formed by the sealing plate 3, the negative pressure detection air membrane 4 and the semipermeable membrane 404 for defoaming. A pair of mounting holes are opened on the outer end wall of the negative pressure detection air membrane 4. A stuffing tube 401 and a negative pressure tube 402 are respectively clamped in the pair of mounting holes. The stuffing tube 401 and the negative pressure tube 402 are respectively connected with the front and rear independent spaces in the negative pressure detection air membrane 4 separated by the semipermeable membrane 404 for defoaming. The stuffing tube 401 is externally connected to a tank body storing a coupling agent, and the negative pressure tube 402 is externally connected to an air pump.

[0052] See also Figure 2-3 The front end of the negative pressure detection air membrane 4 is fixedly connected with a shaping fitting ring 403, and the shaping fitting ring 403 enables the negative pressure detection air membrane 4 to better fit with the pipe wall.

[0053] The negative pressure detection air film 4 and the shaping fitting ring 403 are made of high temperature resistant rubber material, so that when the pipeline to be tested is in service and high-temperature liquid flows therein, the negative pressure detection air film 4 and the shaping fitting ring 403 will not undergo high-temperature deformation, the shaping fitting ring 403 can still maintain a good fit with the pipe wall, and the negative pressure detection air film 4 can still maintain a good negative pressure state.

[0054] See also Figure 6-7The band control terminal 201 can control the band emitted by the probe body 202 through its internal control circuit. During the production, manufacturing and transportation of the coupling agent, bubbles may be mixed in it. These bubbles are filled into the pre-detection probe assembly together with the coupling agent and remain in a thin film formed between the probe body 202 and the measuring surface of the pipe wall, attenuating the energy of the thickness measuring sound wave emitted by the probe body 202, causing distortion of the measurement data. The band control terminal 201 is activated by the thickness measuring terminal 1 to adjust the band emitted by the probe body 202, and the measurement band is converted to The defoaming band is switched to eliminate the bubbles mixed in the filled coupling agent. The ultrasonic vibration is transmitted into the coupling agent, which will cause cavitation in the coupling agent. Since the cavitation generates impact force, the bubbles mixed in the coupling agent can be crushed and separated. At the same time, during the ultrasonic defoaming process, the negative pressure operation in the pre-detection probe assembly does not stop, so that the bubbles separated from the coupling agent can pass through the defoaming semipermeable membrane 404 smoothly and finally be sucked out of the probe through the negative pressure tube 402, thereby accelerating the bubble suction speed. Under the premise of ensuring measurement accuracy, the measurement speed is improved.

[0055] See also Figure 6 The shaping fitting ring 403 is filled with a plurality of metal wire rings, and the shaping effect of the shaping fitting ring 403 is improved by the metal wire rings so as to improve the fitting effect of the shaping fitting ring 403 on the pipe wall of the pipe with different curvature diameters.

[0056] See also Figure 3 The contact pressure between the pressure spring 203 and the pipe wall through the probe body 202 is 2kg when the pressure spring 203 is in the fully compressed state. The pulse wave with a certain bandwidth is used in industrial ultrasonic testing. Therefore, the influence of sound energy attenuation and multiple reflection interference should be mainly considered. Experiments have proved that the coupling layer should be as thin as possible while meeting the detection sensitivity requirements. This is also the reason why the contact pressure of the probe on the detection surface is required to reach 1.5 to 2.5kg during contact flaw detection. The contact pressure between the probe body 202 and the pipe wall reaches 2kg by compressing the pressure spring 203.

[0057] The maximum stretching length of the negative pressure detection air film 4 is less than the stretching limit of the pressure spring 203. The pressure spring 203 is protected by the negative pressure detection air film 4 to avoid the possibility of excessive stretching of the pre-detection probe assembly during transportation and use, thereby losing the elastic squeezing effect on the pipe wall.

[0058] See also Figure 4 The coupling agent is doped with photocurable resin. After the detection operation is completed, the coupling agent filled in the pre-detection probe assembly is irradiated with ultraviolet light. The photocurable resin filled in the coupling agent will solidify synchronously with the coupling agent, so that the solidified coupling agent can be quickly removed from the tube wall and collected, thereby improving the cleaning efficiency.

[0059] Photocurable resin is a water-based resin, which contains more hydrophilic groups or hydrophilic segments and can be emulsified, dispersed or dissolved in water. Combined with the above-mentioned curing and collection, the coupling agent can be recycled and reused.

[0060] See also Figure 1-3 , Figure 8 and Fig.10 , a method for using a high-precision ultrasonic pipeline thickness measuring device, comprising the following steps:

[0061] S1. Grinding the pipe wall: Grinding the defects on the measuring surface of the pipe to be tested;

[0062] S2. Place the probe: Align the probe body 202 with the polished measuring surface, press the housing of the band control terminal 201, and drive the pressure spring 203 to be fully compressed, so that the negative pressure detection air film 4 will fit the outer wall of the pipeline synchronously;

[0063] S3. Pre-detection: Connect the negative pressure tube 402 to a micro air pump, and extract the gas in the negative pressure detection air film 4 through the micro air pump. At this time, only when the defects on the measuring surface of the pipeline are fully polished, the negative pressure detection air film 4 can be stably adsorbed on the measuring surface of the pipe wall. If stable adsorption cannot occur, continue with the polishing process of step S1;

[0064] S4. Filling coupling agent: The filling tube 401 is connected to the coupling agent storage tank, and the coupling agent is injected into the front end space of the negative pressure detection air film 4 separated by the defoaming semipermeable membrane 404;

[0065] S5. Measure the pipe wall: Use the continuous measurement method to measure the thickness of the pipe wall at multiple points along a certain direction and take the average value of the data.

[0066] Please refer to 1-3. Figure 5 and Figure 8-9The present invention performs pre-detection of surface defects at pipeline detection points through a pre-detection probe assembly consisting of a band control terminal 201, a probe body 202, a pressure spring 203, a sealing sheet 3, a negative pressure detection air film 4, a defoaming semi-permeable membrane 404 and a shaping fitting ring 403. During use, the operator first connects the filling tube 401 to a coupling agent storage tank, connects the negative pressure tube 402 to a micro air pump, and then holds the outer shell of the band control terminal 201, aligns the probe body 202 with the polished measuring surface, presses the outer shell of the band control terminal 201, and drives the pressure spring 203 to be fully compressed, so that The probe body 202 is in full contact with the measuring surface on the outer wall of the pipeline, and during the pressing process of the band control terminal 201, the negative pressure detection air film 4 will be synchronously fitted with the outer wall of the pipeline, and then the micro air pump is started to extract the gas in the negative pressure detection air film 4. At this time, only when the defects on the measuring surface of the pipeline are fully polished, the shaping fitting ring 403 can form a good fitting state with the pipe wall, and there is no gap between them. In this way, a good negative pressure state can be formed between the negative pressure detection air film 4 and the measuring surface of the pipe wall, and the pre-detection probe assembly can be stably adsorbed on the measuring surface of the pipeline through the internal and external pressure difference of the negative pressure detection air film 4;

[0067] Then, the operator injects the coupling agent into the front end space of the negative pressure detection air film 4 separated by the defoaming semipermeable membrane 404 through the filling tube 401, and makes the coupling agent fully fill the space to form a thin film between the probe body 202 and the pipe wall measuring surface, so that the ultrasonic wave can smoothly pass through the coupling agent into the pipe wall to detect the pipe wall thickness. In this way, the surface defects at the pipe measuring surface are pre-detected. Only when the surface defects are completely processed can the pre-detection probe assembly be adsorbed thereon, and only when the pre-detection probe assembly can be adsorbed on the pipeline detection point can the pre-detection probe assembly be moved to the pre-detection probe. A coupling agent is filled between the head assembly and the measuring surface of the pipe wall, and the coupling agent is wrapped in the negative pressure detection air film 4, so that there will be no coupling agent dripping during the process of measuring the multi-point thickness of the pipe wall along a certain direction using the continuous measurement method, which is convenient for subsequent cleaning. The steps of applying the coupling agent and installing the probe are reversed, and the probe is installed first, and then the coupling agent is applied. This makes it convenient for the operator to judge whether the defects on the measuring surface of the pipe wall are well handled by the adsorption effect of the probe on the pipe wall. Only after the defects are well handled, the coupling agent is filled. In this way, the measurement accuracy is greatly improved and the waste of secondary filling of the coupling agent is avoided.

[0068] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high-precision ultrasonic pipeline thickness measuring device, comprising a thickness measuring terminal (1), characterized in that: The thickness measuring terminal (1) is electrically connected to a band control terminal (201) via a data transmission line; a probe body (202) is provided on the front side of the band control terminal (201); a pressure spring (203) is electrically connected between the band control terminal (201) and the probe body (202); a sealing sheet (3) is clamped on the outer end wall of the band control terminal (201); a negative pressure detection air film (4) is fixedly connected to the front end of the sealing sheet (3); a defoaming semipermeable membrane (404) is clamped between the probe body (202) and the negative pressure detection air film (4); and the pressure spring (203) is electrically connected between the band control terminal (201) and the probe body (202). The spring (203) is located in a closed space formed by the sealing plate (3), the negative pressure detection air membrane (4) and the defoaming semipermeable membrane (404). A pair of mounting holes are opened on the outer end wall of the negative pressure detection air membrane (4). A stuffing tube (401) and a negative pressure tube (402) are respectively clamped in the pair of mounting holes. The stuffing tube (401) and the negative pressure tube (402) are respectively connected to the front and rear independent spaces in the negative pressure detection air membrane (4) separated by the defoaming semipermeable membrane (404). The stuffing tube (401) is externally connected to a tank storing a coupling agent, and the negative pressure tube (402) is externally connected to an air pump.

2. A high-precision ultrasonic pipe thickness measuring device according to claim 1, characterized in that: A shaping fitting ring (403) is fixedly connected to the front end of the negative pressure detection air membrane (4).

3. A high-precision ultrasonic pipe thickness measuring device according to claim 2, characterized in that: The shaping fitting ring (403) is filled with a plurality of metal wire rings.

4. A high-precision ultrasonic pipe thickness measuring device according to claim 2, characterized in that: The negative pressure detection air membrane (4) and the shaping fitting ring (403) are made of high temperature resistant rubber material.

5. The high-precision ultrasonic pipe thickness measuring device according to claim 1 is characterized in that: The band control terminal (201) can control the band emitted by the probe body (202) through its internal control circuit.

6. The high-precision ultrasonic pipeline thickness measuring device according to claim 1 is characterized in that: The contact pressure between the pressure spring (203) and the pipe wall through the probe body (202) in the fully compressed state is 2 kg.

7. The high-precision ultrasonic pipe thickness measuring device according to claim 1 is characterized in that: The coupling agent is doped with photocurable resin.

8. The high-precision ultrasonic pipeline thickness measuring device according to claim 7 is characterized in that: The photocurable resin is a water-based resin, and the water-based resin contains a relatively large number of hydrophilic groups or hydrophilic segments.

9. The high-precision ultrasonic pipeline thickness measuring device according to claim 1 is characterized in that: The maximum stretching length of the negative pressure detection air membrane (4) is less than the stretching limit of the pressure spring (203).

10. The method for using a high-precision ultrasonic pipeline thickness measuring device according to claim 1, characterized in that: The following steps are involved: S1. Grinding the pipe wall: Grinding the defects on the measuring surface of the pipe to be tested; S2. Place the probe: Align the probe body (202) with the polished measuring surface, press the outer shell of the band control terminal (201), drive the pressure spring (203) to be fully compressed, and the negative pressure detection air film (4) will be synchronously fitted with the outer wall of the pipeline; S3. Pre-detection: Connect the negative pressure tube (402) to an external micro air pump, and use the micro air pump to extract the gas in the negative pressure detection air film (4). At this time, only when the defects on the measuring surface of the pipeline are fully polished, the negative pressure detection air film (4) can be stably adsorbed on the measuring surface of the pipe wall. If stable adsorption cannot occur, continue the polishing process of step S1; S4. Filling coupling agent: Connect the filling tube (401) to the coupling agent storage tank, and inject the coupling agent into the front end space of the negative pressure detection air film (4) separated by the defoaming semipermeable membrane (404); S5. Measure the pipe wall: Use the continuous measurement method to measure the thickness of the pipe wall at multiple points along a certain direction and take the average value of the data.

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