An electromagnetic ultrasonic transducer with high conversion efficiency and stable water flow impact signal at high temperature

Abstract

The invention discloses an electromagnetic ultrasonic transducer with high conversion efficiency and low water flow impact signal stability under high temperature, comprising a hollow cylinder, a glass plate, a coil, a permanent magnet, a ring body, an inner bottom plate with an L-shaped longitudinal section and an outer bottom plate sleeved outside the inner bottom plate, wherein the inner bottom plate is installed at the bottom of the hollow cylinder, the glass plate is embedded between the hollow cylinder and the inner bottom plate and seals the bottom end of the hollow cylinder, the coil is fixed below the glass plate and extends into the inner bottom plate, the ring body is located on the glass plate and is tightly attached to the hollow cylinder, the bottom of the permanent magnet is tightly inserted into the ring body, the bottom of the ring body extends inwardly for a circle to form a bearing platform for supporting the permanent magnet, an inlet groove and an outlet groove are provided on the ring body, the inlet groove is a notch groove opened upward from the bottom end of the ring body to a level higher than the bearing platform surface, the outlet groove is a notch groove opened downward from the top end of the ring body to a level lower than the bearing platform surface, the inlet groove is communicated with a cooling medium inlet opened on the hollow cylinder, and a cooling medium outlet is also opened on the hollow cylinder.

Description

Technical Field

[0001] The invention relates to the technical field of nondestructive material testing, and in particular to an electromagnetic ultrasonic transducer with high energy conversion efficiency, low water flow impact signal and stable performance at high temperature. Background Art

[0002] As my country enters a new era of development, various alloy materials are widely used in major projects such as lunar exploration, manned spaceflight, and military equipment. However, in the manufacturing of materials, defects such as cracks, shrinkage holes, metal and non-metal inclusions are inevitable, so it is particularly important to detect defective materials in a timely manner and remove them. Among various non-destructive testing methods such as ultrasonic testing, magnetic particle testing, and radiographic testing, ultrasonic testing technology stands out with its strong environmental adaptability, wide application range, and high precision.

[0003] When using conventional piezoelectric ultrasonic testing technology, the surface of the tested part must be pretreated and it needs to be used in conjunction with a coupling agent. Therefore, this technology is mainly aimed at parts that have been processed at room temperature (≤50°). It cannot detect defects in time during the processing of parts and cannot provide a strong basis for timely changing processing strategies. Electromagnetic ultrasonic testing, as a new type of non-destructive testing method, can solve the above problems very well. In electromagnetic ultrasonic testing, the electromagnetic ultrasonic transducer with high transduction efficiency and low water flow impact signal at high temperature forms eddy currents in the skin layer of the tested part through electromagnetic coupling, and then generates ultrasonic waves in the skin layer of the tested part. This is a non-contact non-destructive testing. No coupling agent is required during the testing process, and the surface quality of the tested part is not high. It can be carried out in harsh environments such as high temperature. Therefore, it has a wider range of applications. It can realize non-destructive testing at high temperature, not only can it perform real-time detection on the heat treatment process of metal materials, parts, etc., so as to adjust the processing strategy in time and reduce costs, but also can evaluate and test high-temperature equipment to ensure equipment safety.

[0004] Currently, there is a lack of technology for non-destructive testing of high-temperature materials. Application No. 201610078153.7 discloses an ultra-high temperature electromagnetic ultrasonic sensor, which is filled with high-temperature resistant insulation material in the transducer cavity to ensure that the magnet in the transducer is kept at a low temperature. This method can only achieve a short-term insulation effect, and the transducer cannot be exposed to a high-temperature working environment for a long time. Application No. 201810983490.X discloses a high-temperature resistant and wear-resistant electromagnetic ultrasonic shear wave transducer and a manufacturing method thereof, which adopts a water cooling cycle to achieve the purpose of continuous cooling. This method does not plan the route for water entering the cavity, so the cooling water has a large impact on the permanent magnet, and the permanent magnet is only suspended and fixed in the cavity by two bolts. Under the impact of circulating cooling water, the permanent magnet and the cavity are prone to loosening. In addition, the transducer in this scheme adopts a duplex mode, or the excitation and receiving coils are under the same permanent magnet. Such a placement method will cause the transducer to separate the permanent magnet and the coil with a metal plate to eliminate the eddy current interference generated by the permanent magnet. The metal plate will transfer part of the energy carried by the coil, resulting in a further reduction in the transducer efficiency in a high-temperature environment, thereby affecting the detection accuracy. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an electromagnetic ultrasonic transducer with high energy conversion efficiency and low water flow impact signal stability under high temperature, and the electromagnetic ultrasonic transducer can effectively improve the energy conversion efficiency.

[0006] In order to solve the above technical problems, the present invention adopts the following technical methods: an electromagnetic ultrasonic transducer with high conversion efficiency and low water flow impact signal stability under high temperature, comprising a hollow cylinder with an opening at the bottom, a high temperature resistant glass plate, a coil and a permanent magnet;

[0007] The glass plate is installed at the bottom of the hollow cylinder, and the bottom end of the hollow cylinder is sealed. The coil is fixed below the glass plate. The permanent magnet is installed in the hollow cylinder and close to the top of the glass plate. A cooling medium inlet and a cooling medium outlet are staggered on the hollow cylinder.

[0008] Furthermore, the electromagnetic ultrasonic transducer with high conversion efficiency and low water flow impact signal under high temperature also includes an annular body fixed on the glass plate and tightly attached to the hollow cylinder, the bottom of the permanent magnet is tightly inserted in the annular body, the bottom of the annular body extends a circle inside the annular body to form a supporting platform for supporting the permanent magnet, and an inlet groove and an outlet groove are also provided on the annular body, the inlet groove is a notch groove opened from the bottom end of the annular body upward to above the supporting platform surface, and the outlet groove is a notch groove opened from the top end of the annular body downward to below the supporting platform surface; the cooling medium inlet and the cooling medium outlet are distributed one above and one below, the cooling medium inlet is directly connected to the inlet groove, and the top wall of the cooling medium inlet is lower than the top of the inlet groove.

[0009] Furthermore, the annular body is provided with one inlet groove and three outlet grooves, and the one inlet groove and the three outlet grooves are evenly distributed on the annular body.

[0010] Furthermore, the portion of the annular body where the inlet groove is provided protrudes upward in an arch shape, and the depth of the inlet groove is greater than the depth of the outlet groove.

[0011] Furthermore, the top of the permanent magnet abuts against the top of the hollow cylinder through a spring sheet.

[0012] Furthermore, the electromagnetic ultrasonic transducer with high conversion efficiency and stable water flow impact signal under high temperature also includes an inner bottom plate with an L-shaped longitudinal section, the inner bottom plate is installed at the bottom of the hollow cylinder, the glass plate is embedded between the hollow cylinder and the inner bottom plate, the coil extends to the middle of the inner bottom plate and the lowest point of the coil is not higher than the bottom surface of the inner bottom plate.

[0013] Furthermore, the electromagnetic ultrasonic transducer with high conversion efficiency and low water flow impact signal under high temperature also includes an outer bottom plate that is sleeved outside the inner bottom plate. The inner bottom plate and the outer bottom plate are fixed with multiple bolts, and the outer bottom plate is equipped with multiple universal rollers for easy movement.

[0014] Furthermore, the top of the hollow cylinder is a detachable upper end cover.

[0015] Furthermore, a circle of sealing grooves is respectively formed at the top and bottom ends of the hollow cylinder, and sealing strips are installed in the sealing grooves.

[0016] Preferably, the coil is glued to the bottom of the glass plate with high temperature resistant glue, and the gap between the coil and the inner bottom plate is also filled with high temperature resistant glue.

[0017] Compared with the traditional transducer, the electromagnetic ultrasonic transducer with high conversion efficiency and low water flow impact signal stability under high temperature proposed by the present invention has the advantages of low impact force of cooling medium, high cooling efficiency, high conversion efficiency and convenient movement, which can effectively realize the requirements of high temperature, high precision, continuous and rapid non-destructive testing during detection. Specifically, in the present invention, the permanent magnet and the coil are separated by a glass plate. The traditional electromagnetic ultrasonic transducer uses a metal plate to separate the two, which will cause the eddy current density generated on the surface of the specimen to decrease, and the conversion efficiency is reduced. However, the present invention uses a glass plate to separate the permanent magnet and the coil, which will not affect the electromagnetic coupling between the three, and will not affect the size of the eddy current on the surface of the specimen. Most of the energy carried by the coil can be transferred to the surface of the tested test piece, effectively improving the conversion efficiency and improving the accuracy of electromagnetic ultrasonic detection and defect determination. In addition, the present invention uses the ingenious design of the annular body to plan the flow route of the cooling medium, reduce the impact of the cooling medium on the permanent magnet, and improve the cooling efficiency. The electromagnetic ultrasonic transducer can maintain a low temperature for a long time and is stable and durable. Furthermore, the present invention adopts a detachable structure of the inner bottom plate and the outer bottom plate, which can quickly and conveniently replace the probe and ensure the smooth progress of different detection projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a cross-sectional view of the electromagnetic ultrasonic transducer with high conversion efficiency, low water flow impact signal stability under high temperature according to the present invention;

[0019] Figure 2 An exploded view of the electromagnetic ultrasonic transducer with high energy conversion efficiency, low water flow impact signal stability under high temperature according to the present invention;

[0020] Figure 3 It is an axonometric view of a hollow cylinder of the electromagnetic ultrasonic transducer with high energy conversion efficiency, low water flow impact signal stability under high temperature according to the present invention;

[0021] Figure 4 It is an axonometric view of the annular body of the electromagnetic ultrasonic transducer with high energy conversion efficiency, low water flow impact signal stability under high temperature involved in the present invention;

[0022] Figure 5 It is an axonometric view of the universal roller of the electromagnetic ultrasonic transducer with high energy conversion efficiency and low water flow impact signal stability under high temperature involved in the present invention;

[0023] In the attached figure:

[0024] 1——Hollow cylinder 2——Glass plate 3——Coil

[0025] 4——Permanent magnet 5——Ring body 6——Spring sheet

[0026] 7——Inner bottom plate 8——Outer bottom plate 9——Bolt

[0027] 10——Universal roller

[0028] 101——Cooling medium inlet 102——Cooling medium outlet

[0029] 103——Upper end cover 104——Sealing groove

[0030] 501——Carrying platform 502——Inlet slot

[0031] 503 - Exit slot. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0033] like Figure 1 and Figure 2 As shown, an electromagnetic ultrasonic transducer with high conversion efficiency and low water flow impact signal stability under high temperature includes a hollow cylinder 1 with an opening at the bottom, a high temperature resistant glass plate 2, a coil 3 and a permanent magnet 4. The glass plate 2 is installed at the bottom of the hollow cylinder 1, the bottom of the hollow cylinder 1 is sealed, the coil 2 is fixed below the glass plate 2, the permanent magnet 4 is installed in the hollow cylinder 1 and close to the top of the glass plate 2, and a cooling medium inlet 101 and a cooling medium outlet 102 are staggered on the hollow cylinder 1.

[0034] It should be noted that the electromagnetic ultrasonic transducer adopts one transmission and one reception, the excitation coil is in one electromagnetic ultrasonic transducer, and the receiving coil is in another electromagnetic ultrasonic transducer, and the two are used in combination. The coil 3 involved in the present invention is an excitation coil or a receiving coil. In order to ensure that different detection items can be carried out quickly and normally, various types of electromagnetic ultrasonic transducers with excitation coils and electromagnetic ultrasonic transducers with receiving coils can be prepared in advance.

[0035] like Figure 1 and 2As shown, the permanent magnet 4 and the coil 3 are obviously separated by the glass plate 2. The traditional electromagnetic ultrasonic transducer uses a metal plate to separate the two. The sensitivity and signal-to-noise ratio of the electromagnetic ultrasonic transducer are not only related to the size of the bias magnetic field, but also mainly affected by the strength of the induced eddy current of the coil in the metal skin layer to be detected. The metal plate is used to separate the permanent magnet and the coil, and the metal plate will also generate corresponding eddy currents, resulting in a decrease in the eddy current density generated on the surface of the specimen, thereby reducing the energy conversion efficiency and changing the electromagnetic coupling between the permanent magnet, the coil and the specimen. The present invention uses a glass plate 2 to separate the permanent magnet 4 and the coil 3, which can make the distance between the two larger, and will not affect the electromagnetic coupling between the three, and will not affect the size of the eddy current on the surface of the specimen. Most of the energy carried by the coil 3 can be transferred to the surface of the test piece to be tested, effectively improving the energy conversion efficiency and improving the accuracy of electromagnetic ultrasonic detection and defect determination.

[0036] In order to enable the electromagnetic ultrasonic transducer with high conversion efficiency and low water flow impact signal under high temperature to be used in a high temperature environment, a cooling medium inlet 101 and a cooling medium outlet 102 are staggered on the hollow cylinder 1. Before placing the present invention in a high temperature environment, an external cooling source with a self-driven pump allows the cooling medium "water" (or other cooling media suitable for permanent magnet cooling in the prior art) to enter the hollow cylinder 1 through the cooling medium inlet 101, and then flow out from the cooling medium outlet 102 to form a water circulation loop. After the present invention leaves the high temperature environment, water is continued to flow for 10 minutes, thereby achieving cooling of the permanent magnet 4 in the hollow cylinder 1.

[0037] It is worth pointing out that in the process of water circulation cooling, if the water flow is not well controlled, the flowing water may cause impact on the permanent magnet 4, resulting in the problem of "the permanent magnet and the cavity are prone to loosening under the impact of circulating cooling water" existing in the high temperature and wear-resistant electromagnetic ultrasonic shear wave transducer disclosed in application number 201810983490.X. Therefore, it is necessary to plan the route for water to enter the hollow cylinder 1. In view of this, the electromagnetic ultrasonic transducer with high conversion efficiency, low water flow impact signal and stable signal under high temperature proposed by the present invention also includes an annular body 5 fixed on the glass plate 2 and tightly attached to the hollow cylinder 1, the bottom of the permanent magnet 4 is tightly inserted in the annular body 5, and the bottom of the annular body 5 extends a circle inside the annular body 5 to form a supporting platform 501 supporting the permanent magnet 4, and an inlet groove 502 and an outlet groove 503 are also opened on the annular body 5, the inlet groove 502 is a notch groove opened from the bottom end of the annular body 5 upward to above the surface of the supporting platform 501, and the outlet groove 503 is a notch groove opened from the top end of the annular body 5 downward to below the surface of the supporting platform 501; Figure 1-3As shown, the cooling medium inlet 101 and the cooling medium outlet 102 are arranged one above the other, the cooling medium inlet 101 is directly connected to the inlet groove 502 , and the top wall of the cooling medium inlet 101 is lower than the top of the inlet groove 502 .

[0038] The number of the aforementioned inlet grooves 502 and outlet grooves 503 can be determined according to actual conditions. As long as the water flow can be kept smooth, there can be multiple inlet grooves 502 and outlet grooves 503. In the present embodiment, there is one inlet groove 502 and three outlet grooves 503. The one inlet groove 502 and the three outlet grooves 503 are evenly distributed on the annular body 5.

[0039] During the water circulation process, after the water reaches the inlet groove 502 through the cooling medium inlet 101, since the side wall of the permanent magnet 4 is close to the inlet groove 502, the water cannot flow out directly along the inner wall of the hollow cylinder 1, and the opening of the inlet groove 502 is downward, so the water can flow through the side of the support platform 502 to the lower part of the permanent magnet 4, and since the bottom of the three outlet grooves 503 is lower than the table surface of the support platform 502, the water under the permanent magnet 4 can slowly flow through the three outlet grooves 503 to the gap between the hollow cylinder 1 and the permanent magnet 4, and then fill it up and discharge it through the cooling medium outlet 102 to form a water circulation loop. This design realizes the cooling route of water from bottom to top, reduces the impact of cooling water on the permanent magnet 4, and improves the cooling efficiency, so that the electromagnetic ultrasonic transducer can be kept at a low temperature for a long time, and is more stable and durable.

[0040] To ensure that the water inlet amount in the hollow cylinder 1 is not less than the water outlet amount, the inlet groove 502 on the annular body 5 is preferably larger than the outlet groove 503. Specifically, Figure 4 As shown, the portion of the annular body 5 where the inlet groove 502 is provided protrudes upward in an arch shape, and the depth of the inlet groove 502 is greater than the depth of the outlet groove 503 .

[0041] In order to further strengthen the firmness of the permanent magnet 4 fixed in the hollow cylinder 1, in addition to tightly inserting the permanent magnet 4 into the annular body 5, a spring sheet 6 against the top of the hollow cylinder 1 can be added to the top of the permanent magnet 4. The annular body 5 and the spring sheet 6 can cooperate to restrain the position of the permanent magnet, so that it remains fixed under the impact of cooling water, providing a stable magnetic field, and ensuring that the sensor can be used in a variety of harsh environments.

[0042] The glass plate 2 of the aforementioned electromagnetic ultrasonic transducer is located at the bottom of the hollow cylinder 1, and wear may occur under certain circumstances. In order to avoid this problem as much as possible, the electromagnetic ultrasonic transducer involved in the present invention can also install an inner bottom plate 7 at the bottom of the hollow cylinder 1. The longitudinal section of the inner bottom plate is L-shaped. The glass plate 2 is embedded between the hollow cylinder 1 and the inner bottom plate 7. The coil 3 extends in the middle of the inner bottom plate 7 and the lowest point of the coil 3 is not higher than the bottom surface of the inner bottom plate 7, and can be flush with the bottom surface of the inner bottom plate 7. It is worth mentioning that the coil 3 is glued to the bottom of the glass plate 2 with high-temperature resistant glue, and the gap between the coil 3 and the inner bottom plate 7 is also filled with high-temperature resistant glue, which not only plays a role of reinforcement, but also can prevent the accumulation of dust and debris in the gap between the coil 3 and the inner bottom plate 7.

[0043] Considering that different detection purposes require different waves in actual applications, that is, different coils are required, for example: a zigzag coil is required to detect surface waves, and a spiral coil is required to detect transverse waves. Therefore, the coil may need to be replaced frequently during use. For this reason, the present invention designs a separate electromagnetic ultrasonic transducer, which, on the basis of the aforementioned structure, is further equipped with an outer bottom plate 8, which is sleeved on the outside of the inner bottom plate 7, and the inner bottom plate 7 and the outer bottom plate 8 are fixed by multiple bolts 9. When replacement is required, the probe (the probe refers to other structures in the electromagnetic ultrasonic transducer other than the outer bottom plate 8) can be removed from the outer bottom plate 8 by disassembling the bolts 9, and a suitable probe can be replaced to continue detection. This method can quickly and conveniently replace the probe.

[0044] In addition, in order to facilitate the movement of the present invention on the surface of the test piece during the detection process, as Figure 5 As shown, a plurality of universal rollers 10 can be installed on the outer bottom plate 8. With the universal rollers 10, it is also possible to avoid the coil 3 from rubbing against the surface of the test piece, thereby avoiding affecting the service life of the transducer.

[0045] like Figure 2 As shown, the top of the hollow cylinder 1 may be a detachable upper end cover 103. The purpose of designing such a detachable structure is to facilitate the manufacture and assembly of the present invention.

[0046] In order to prevent cooling water from leaking out of the hollow cylinder 1 and affecting the overall cooling performance, a circle of sealing grooves 104 are respectively provided at the top and bottom of the hollow cylinder 1 , and sealing strips are installed in the sealing grooves 104 .

[0047] The sensitivity and signal-to-noise ratio of the electromagnetic ultrasonic transducer, in addition to the size of the bias magnetic field, are mainly affected by the strength of the induced eddy current generated by the coil in the skin layer of the metal being detected. In previous high-temperature transducers, the copper partition will also generate corresponding eddy currents, resulting in a reduction in the eddy currents generated on the surface of the specimen. In the present invention, the glass backplane replaces the previous copper backplane. The distance between the magnet and the coil is large, and the electrical conductivity of the magnet is much smaller than the copper backplane used in the past, so the eddy current generated on the surface of the magnet is much smaller than the eddy current generated in the copper backplane. Furthermore, most of the energy in the coil can be converted into eddy currents on the surface of the specimen. Under this setting, the energy conversion efficiency of the transducer can be effectively improved.

[0048] From the above, it can be seen that the electromagnetic ultrasonic transducer with high transduction efficiency, low water flow impact signal and stable signal under high temperature provided by the present invention has the advantages of low impact force of cooling water, high cooling efficiency, high transduction efficiency and convenient movement, and realizes the requirements of high-precision, continuous and rapid non-destructive testing under high temperature in practical applications.

[0049] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention may also be implemented in other ways. Any obvious replacement without departing from the concept of the present technical solution is within the protection scope of the present invention.

[0050] In order to make it easier for ordinary technicians in the field to understand the improvements of the present invention over the prior art, some drawings and descriptions of the present invention have been simplified, and for the sake of clarity, some other elements are omitted in this application document. Ordinary technicians in the field should realize that these omitted elements may also constitute the content of the present invention.

Claims

1. An electromagnetic ultrasonic transducer with high conversion efficiency and low water flow impact signal stability under high temperature, characterized by: It comprises a hollow cylinder (1) with an opening at the bottom, a high temperature resistant glass plate (2), a coil (3) and a permanent magnet (4); The glass plate (2) is mounted on the bottom of the hollow cylinder (1), and the bottom end of the hollow cylinder (1) is sealed; the coil (3) is fixed below the glass plate (2); the permanent magnet (4) is mounted in the hollow cylinder (1) and close to the top of the glass plate (2); and a cooling medium inlet (101) and a cooling medium outlet (102) are staggeredly opened on the hollow cylinder (1); The electromagnetic ultrasonic transducer also comprises an annular body (5) fixed on the glass plate (2) and closely attached to the hollow cylinder (1); the bottom of the permanent magnet (4) is tightly inserted into the annular body (5); the bottom of the annular body (5) extends inwardly of the annular body (5) to form a support platform (501) for supporting the permanent magnet (4); an inlet groove (502) and an outlet groove (503) are also provided on the annular body (5); the inlet groove (502) is a notch groove extending upward from the bottom end of the annular body (5) to a position higher than the surface of the support platform (501); and the outlet groove (503) is a notch groove extending downward from the top end of the annular body (5) to a position lower than the surface of the support platform (501); The cooling medium outlet (102) and the cooling medium inlet (101) are arranged one above the other, the cooling medium inlet (101) is directly connected to the inlet groove (502), and the top wall of the cooling medium inlet (101) is lower than the top of the inlet groove (502); The top of the permanent magnet (4) is pressed against the top of the hollow cylinder (1) via a spring sheet (6); The electromagnetic ultrasonic transducer further comprises an inner bottom plate (7) having an L-shaped longitudinal section, the inner bottom plate (7) being mounted on the bottom of the hollow cylinder (1), the glass plate (2) being embedded between the hollow cylinder (1) and the inner bottom plate (7), the coil (3) extending in the middle of the inner bottom plate (7) and the lowest point of the coil (3) being no higher than the bottom surface of the inner bottom plate (7).

2. The electromagnetic ultrasonic transducer with high conversion efficiency, low water flow impact signal stability under high temperature according to claim 1, characterized in that: The annular body (5) has one inlet groove (502) and three outlet grooves (503), and the one inlet groove (502) and the three outlet grooves (503) are evenly distributed on the annular body (5).

3. The electromagnetic ultrasonic transducer with high conversion efficiency, low water flow impact signal stability under high temperature according to claim 2, characterized in that: The portion of the annular body (5) where the inlet groove (502) is provided protrudes upward in an arch shape, and the depth of the inlet groove (502) is greater than the depth of the outlet groove (503).

4. The electromagnetic ultrasonic transducer with high conversion efficiency, low water flow impact signal stability under high temperature according to claim 3, characterized in that: It also includes an outer bottom plate (8) sleeved outside the inner bottom plate (7), wherein the inner bottom plate (7) and the outer bottom plate (8) are fixed by a plurality of bolts (9), and a plurality of universal rollers (10) are mounted on the outer bottom plate (8) for easy movement.

5. The electromagnetic ultrasonic transducer with high conversion efficiency, low water flow impact signal stability under high temperature according to claim 4, characterized in that: The top of the hollow cylinder (1) is a detachable upper end cover (103).

6. The electromagnetic ultrasonic transducer with high conversion efficiency, low water flow impact signal stability under high temperature according to claim 5, characterized in that: A circle of sealing grooves (104) are respectively formed at the top and bottom ends of the hollow cylinder (1), and sealing strips are installed in the sealing grooves (104).

7. The electromagnetic ultrasonic transducer with high conversion efficiency, low water flow impact signal stability under high temperature according to claim 6, characterized in that: The coil (3) is glued to the bottom of the glass plate (2) using high temperature resistant glue, and the gap between the coil (3) and the inner bottom plate (7) is also filled with high temperature resistant glue.

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