Ultrasonic transducer and ultrasonic flowmeter

Abstract

The embodiment of the present application provides an ultrasonic transducer and an ultrasonic flowmeter. The ultrasonic transducer comprises a metal shell, a piezoelectric element and a shell, the metal shell comprises a barrel-shaped body and a mounting portion, the mounting portion is arranged at an opening end of the barrel-shaped body, the piezoelectric element is arranged on an inner bottom wall of the barrel-shaped body in a matched mode, the shell comprises a cylindrical body and a connecting portion, the connecting portion is arranged on the cylindrical body, the connecting portion is connected with the mounting portion, the metal shell is sleeved in the cylindrical body, and a first buffer gap exists between a side wall of the cylindrical body and a side wall of the barrel-shaped body. The ultrasonic flowmeter comprises the ultrasonic transducer. The ultrasonic transducer and the ultrasonic flowmeter are used to improve the accuracy of a detection signal.

Description

Technical Field

[0001] This application relates to the field of instrumentation technology, and in particular to an ultrasonic transducer and an ultrasonic flow meter. Background Technology

[0002] An ultrasonic flow meter is an instrument that calculates the flow velocity and flow rate of a fluid by measuring the time difference between the propagation of ultrasonic waves in the upstream and downstream directions. Compared to traditional mechanical flow meters, such as turbine flow meters and orifice plate flow meters, ultrasonic flow meters have advantages such as good stability, high measurement accuracy, wide measurement range, low maintenance rate, low pressure loss, and convenient installation. The core component of an ultrasonic flow meter is the ultrasonic transducer, which is used to transmit and receive ultrasonic signals. The performance of the ultrasonic transducer directly affects the measurement accuracy and stability of the ultrasonic flow meter.

[0003] An ultrasonic transducer typically includes a metal shell, a matching layer, a piezoelectric ceramic, a backing, an outer shell, and a cover. The metal shell is bowl-shaped. The matching layer is located on the outside of the metal shell and adheres to the outer side of the bottom wall of the metal shell. The piezoelectric ceramic is located in the hollow area enclosed by the metal shell and adheres to the inner side of the bottom wall of the metal shell. The piezoelectric ceramic is energized through lead wires, and thus converts electrical signals into mechanical signals, or vice versa, through the piezoelectric effect. The outer shell is cylindrical, with a cover covering one open end of the outer shell. The metal shell, along with the piezoelectric ceramic and matching layer adhered to both sides of the metal shell, is located inside the cavity enclosed by the outer shell. The matching layer is exposed at the other open end of the outer shell. The cover, outer shell, and metal shell are sealed together, with the air within the sealed cavity serving as the backing.

[0004] However, after receiving an electrical signal, the piezoelectric element will not only generate beneficial axial vibration, but also harmful radial vibration. That is, the radial vibration of the piezoelectric element is noise. The radial vibration of the piezoelectric element will be transmitted to the side wall of the metal shell, and the radial vibration of the side wall of the metal shell will be transmitted to the side wall of the outer shell connected to it. The radial vibration of the outer shell side wall and the axial vibration excited by the piezoelectric element, the metal shell and the matching layer will cause sound wave reverberation, resulting in a decrease in signal accuracy. Utility Model Content

[0005] This application provides an ultrasonic transducer and an ultrasonic flow meter to improve signal accuracy.

[0006] In a first aspect, embodiments of this application provide an ultrasonic transducer, comprising: a metal shell including a barrel-shaped body and a mounting portion, the mounting portion being disposed at the open end of the barrel-shaped body; a piezoelectric element being attached to the inner bottom wall of the barrel-shaped body; and an outer shell including a cylindrical body and a connecting portion, the connecting portion being disposed on the cylindrical body and connected to the mounting portion, the metal shell being fitted inside the cylindrical body, and a first buffer gap existing between the side wall of the cylindrical body and the side wall of the barrel-shaped body.

[0007] In one possible implementation, the outer casing further includes an annular flange disposed at one end of the cylindrical body and extending inward relative to the side wall of the cylindrical body; a second buffer gap exists between the annular flange and the bottom wall of the cylindrical body, and the second buffer gap communicates with the first buffer gap.

[0008] In one possible implementation, the ultrasonic transducer further includes: a sound matching element, which is fitted onto the outer bottom wall of the barrel-shaped body, and the outer side wall of the sound matching element is disposed opposite to the inner side wall of the annular flange; a third buffer gap exists between the inner side wall of the annular flange and the outer side wall of the sound matching element, and the third buffer gap communicates with the second buffer gap.

[0009] In one possible implementation, the inner bottom wall of the barrel-shaped body is circular, and the diameter of the inner bottom wall is d; the transition fillet between the side wall and the bottom wall of the barrel-shaped body is R; the sound matching component is a circular plate structure, and the diameter of the sound matching component is D; wherein, D≤d-2R.

[0010] In one possible implementation, the size of the first buffer gap is L, and the wall thickness of the barrel-shaped body is H, wherein L≥H*10%.

[0011] In one possible implementation, the mounting part is a mounting flange provided at the open end of the barrel-shaped body, the mounting flange extending outward relative to the side wall of the barrel-shaped body; the barrel-shaped body includes a first cylindrical section and a second cylindrical section, the inner diameter of the first section is smaller than the inner diameter of the second section, a support step is formed between the first section and the second section, the support step is located inside the barrel-shaped body, and the support step constitutes a connecting part; the support step connects to and supports the mounting flange.

[0012] In one possible implementation, the ultrasonic transducer further includes: a damping element, comprising a first damping ring and a second damping ring, wherein the first damping ring is disposed at one end of the second damping ring and protrudes along the edge of the second damping ring toward the outer wall of the second damping ring; the outer diameter of the first segment is smaller than the outer diameter of the second segment, the first segment is disposed at one end of the second segment, and a boss is formed between the first segment and the second segment, the boss being located outside the cylindrical body; wherein the first damping ring is fitted against the outer wall of the first segment, and the second damping ring is fitted against the stepped surface of the boss.

[0013] In one possible implementation, the height between the lower end face of the mounting flange and the inner bottom wall of the barrel-shaped body is h, the inner bottom wall of the barrel-shaped body is circular and has an inner diameter of d, where h ≥ ¼ * d.

[0014] In one possible implementation, the cylindrical body further includes a cylindrical third section with an inner diameter larger than that of the second section. The third section is disposed at the other end of the second section away from the first section, and an installation step is formed between the third section and the second section. The ultrasonic transducer also includes a back plate disposed on the installation step and covering the opening of the cylindrical body near the piezoelectric element.

[0015] Secondly, embodiments of this application provide an ultrasonic flow meter, which includes the ultrasonic transducer described above.

[0016] The ultrasonic transducer and ultrasonic flow meter provided in this application embodiment use a piezoelectric element for the conversion between electrical energy and mechanical energy, a metal shell for supporting the piezoelectric element, and an outer shell for protecting the metal shell and the piezoelectric element disposed inside the metal shell. A first buffer gap exists between the sidewall of the cylindrical body of the outer shell and the sidewall of the barrel-shaped body of the metal shell. Air is diffused between the first buffer gap and the sidewall of the cylindrical body, as well as between the air and the sidewall of the barrel-shaped body, forming an acoustic impedance abrupt change interface that can reflect most of the vibration energy. Thus, when the piezoelectric element receives an electrical signal and vibrates, most of the radial vibration of the piezoelectric element along the metal shell cannot be transmitted to the sidewall of the outer shell due to the existence of the first buffer gap. This effectively reduces the resonance of the outer shell, thereby effectively eliminating noise vibration and improving the measurement accuracy of the ultrasonic transducer and ultrasonic flow meter. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] Figure 1 A cross-sectional view of the ultrasonic transducer provided in this application;

[0019] Figure 2 Schematic diagram of the ultrasonic transducer provided in this application Figure 1 ;

[0020] Figure 3 Schematic diagram of the ultrasonic transducer provided in this application Figure 2 ;

[0021] Figure 4 for Figure 1 Enlarged view of a portion of point A in the middle.

[0022] Figure label:

[0023] 100: Metal casing; 101: Barrel-shaped body; 102: Mounting flange;

[0024] 200: Piezoelectric element;

[0025] 300: Outer shell; 301: Cylindrical body; 302: Connecting part; 303: First buffer gap; 304: Annular flange; 305: Second buffer gap; 306: Third buffer gap; 307: First section; 308: Second section; 309: Boss; 310: Supporting step; 311: Third section; 312: Mounting step;

[0026] 400: Voice matching component;

[0027] 500: Shock absorber; 501: First shock absorber ring; 502: Second shock absorber ring;

[0028] 600: Back panel.

[0029] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0030] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application.

[0031] First, a detailed analysis of the problems with existing technologies is conducted.

[0032] An existing ultrasonic transducer includes a metal shell, a matching layer, a piezoelectric ceramic, and a backing. The metal shell is bowl-shaped. The matching layer is located on the outside of the metal shell and adheres to the outer side of the bottom wall of the metal shell. The piezoelectric ceramic is located in the hollow area enclosed by the metal shell and adheres to the inner side of the bottom wall of the metal shell. The piezoelectric ceramic is connected to electricity through lead wires, and thus converts electrical signals into mechanical signals, or vice versa, through the piezoelectric effect. The backing material is typically TPE (Thermoplastic Elastomer, a polymer material combining the elasticity of rubber and the processability of plastics) or TPEE (Thermoplastic Polyester Elastomer, a high-performance linear block copolymer combining the elasticity of rubber and the processability of thermoplastics). The backing encapsulates the metal shell to provide damping and reduce reverberation.

[0033] However, the backing materials of TPE and TPEE typically have a Shore A hardness of 60-80. While this low hardness can provide shock absorption, when the ultrasonic transducer is installed in a complex working environment with large temperature and humidity variations or fluids that can damage the TPE and TPEE materials, the backing is prone to deformation and cracking. This prevents the TPE and TPEE backing from isolating the components from the external environment, leading to difficulties in signal reception, inability to adapt to complex environments, and reduced service life.

[0034] To address this, existing technology provides another ultrasonic transducer, comprising a metal shell, a matching layer, a piezoelectric ceramic, a backing, an outer shell, and a cover. The metal shell is bowl-shaped. The matching layer is disposed on the outside of the metal shell and adheres to the outer side of the bottom wall of the metal shell. The piezoelectric ceramic is disposed within the hollow area enclosed by the metal shell and adheres to the inner side of the bottom wall of the metal shell. The piezoelectric ceramic is energized via lead wires, thereby converting electrical signals into mechanical signals, or vice versa, through the piezoelectric effect. The outer shell is cylindrical, with the cover covering one open end of the outer shell. The metal shell, along with the piezoelectric ceramic and matching layer adhered to both sides of the metal shell, is disposed inside the cavity enclosed by the outer shell. The matching layer is exposed at the other open end of the outer shell. The cover, outer shell, and metal shell are sealed together, with the air within the sealed cavity serving as the backing.

[0035] However, after receiving an electrical signal, the piezoelectric element will not only generate beneficial axial vibration, but also harmful radial vibration. That is, the radial vibration of the piezoelectric element is noise. The radial vibration of the piezoelectric element will be transmitted to the side wall of the metal shell, and the radial vibration of the side wall of the metal shell will be transmitted to the side wall of the outer shell connected to it. The radial vibration of the outer shell side wall and the axial vibration excited by the piezoelectric element, the metal shell and the matching layer will cause sound wave reverberation, which will reduce the accuracy of the signal.

[0036] Based on the above scenario, it can be seen that in the existing technology, the sound waves excited by the radial vibration of the outer shell sidewall and the metal shell sidewall are in contact, and the sound waves excited by the axial vibration of the piezoelectric element, the metal shell and the matching layer are reverberated, which leads to a decrease in signal accuracy.

[0037] The ultrasonic transducer and ultrasonic flow meter provided in this application are connected to the outer shell through the end of the metal shell, and a gap exists between the side wall of the metal shell and the side wall of the outer shell. The air in the gap forms an interface with abrupt change in acoustic impedance, which reflects most of the vibration energy. This solves the technical problem of reduced signal accuracy caused by the reverberation of the sound waves excited by the radial vibration of the outer shell side wall and the sound waves excited by the axial vibration of the piezoelectric element, the metal shell, and the matching layer.

[0038] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0039] Figure 1 This is a cross-sectional view of the ultrasonic transducer provided in this application. Figure 2 Schematic diagram of the ultrasonic transducer provided in this application Figure 1 , Figure 3 Schematic diagram of the ultrasonic transducer provided in this application Figure 2 The ultrasonic transducer provided in this application can be used in ultrasonic flow meters.

[0040] like Figures 1-3 As shown, this embodiment provides an ultrasonic transducer, which includes a metal shell 100, a piezoelectric element 200, a sound matching component 400, and a housing 300. The metal shell 100 serves as the mounting reference for the piezoelectric element 200 and the sound matching component 400. The piezoelectric element 200 is a device that converts electrical energy into mechanical energy based on the piezoelectric effect. The sound matching component 400 reduces ultrasonic wave reflection and improves ultrasonic wave transmission efficiency through acoustic impedance matching; the sound matching component 400 is used to receive and transmit ultrasonic waves. The housing 300 protects the metal shell 100 and the piezoelectric element 200.

[0041] like Figure 1 As shown, the metal shell 100 includes a barrel-shaped body 101 and a mounting portion, which is disposed at the open end of the barrel-shaped body 101. The side wall and bottom wall of the barrel-shaped body 101 enclose a cavity with an opening, and the open end of the barrel-shaped body 101 is the end of the barrel-shaped body 101 that is close to the opening and away from the bottom wall of the barrel-shaped body 101.

[0042] For example, such as Figure 1 As shown, the mounting part is a mounting flange 102 provided at the open end of the barrel-shaped body 101. The mounting flange 102 extends outward relative to the side wall of the barrel-shaped body 101, and the mounting flange 102 can be annular. The mounting flange 102 and the barrel-shaped body 101 can be an integral structure and can be formed by stamping.

[0043] For example, the metal shell 100 can be made of metal materials, such as stainless steel, stainless iron, copper, etc. In this way, the metal shell 100 has high rigidity and can suppress the lateral deformation of the piezoelectric element 200.

[0044] like Figure 1 As shown, the piezoelectric element 200 is attached to the inner bottom wall of the barrel-shaped body 101. Specifically, the piezoelectric element 200 can be in the shape of a disc, and is bonded to the inner bottom wall of the barrel-shaped body 101 by an adhesive. The material of the piezoelectric element 200 can be piezoelectric ceramic or piezoelectric crystal. Commonly used barium titanate and lead zirconate titanate piezoelectric ceramics can be used, and commonly used piezoelectric crystals can be used.

[0045] like Figures 1-3 As shown, the sound matching component 400 is attached to the outer bottom wall of the barrel-shaped body 101. For example, the sound matching component 400 can be in the shape of a disc, and it can be adhered to the outer bottom wall of the barrel-shaped body 101 using an adhesive. The sound matching component 400 and the piezoelectric element 200 are disposed opposite each other on opposite sides of the bottom wall of the barrel-shaped body 101. The impedance value of the sound matching component 400 is generally between the impedance value of the piezoelectric element 200 and the impedance value of the fluid.

[0046] In one implementation, such as Figure 1 , Figure 3 and Figure 4As shown, the inner bottom wall of the barrel-shaped body 101 is circular with a diameter of d. The transition radius between the side wall and the bottom wall of the barrel-shaped body 101 is R. The sound matching component 400 is a circular plate structure with a diameter of D, where D ≤ d - 2R. In this way, the sound matching component 400 can completely fit against the bottom wall of the barrel-shaped body 101, effectively reducing the gap between the edge of the sound matching component 400 and the edge of the bottom wall of the barrel-shaped body 101. This reduces noise generated at the edge of the sound matching component 400 due to the presence of this gap, thereby improving the measurement accuracy of the ultrasonic transducer. Of course, for the inequality D ≤ d - 2R to be meaningful, the transition radius R between the side wall and the bottom wall of the barrel-shaped body 101 needs to satisfy R ≤ ½d.

[0047] like Figure 1 and Figure 4 As shown, the outer casing 300 includes a cylindrical body 301 and a connecting part 302. The connecting part 302 is disposed on the cylindrical body 301 and is connected to the mounting part.

[0048] exist Figure 1 In the illustrated embodiment, the cylindrical body 301 includes a cylindrical first segment 307 and a cylindrical second segment 308. The inner diameter of the first segment 307 is smaller than the inner diameter of the second segment 308. A support step 310 is formed between the first segment 307 and the second segment 308. The support step 310 is located inside the cylindrical body 301 and constitutes a connecting portion 302. The support step 310 connects to and supports the mounting flange 102, and the support step 310 can be connected to the mounting flange 102 by adhesive bonding.

[0049] It is worth noting that the linear expansion coefficient of the metal shell 100 is typically 10-18 ppm / °C, while that of the plastic or composite shell 300 is typically 50-200 ppm / °C. The significant difference in their linear expansion coefficients means that when the metal shell 100 and shell 300 are connected, internal stress can easily be generated in both. This internal stress is transmitted to the piezoelectric element 200 and the sound matching component 400 on the metal shell 100 through the adhesive bonding. This internal stress affects the piezoelectric effect of the piezoelectric element 200 and the performance of the sound matching component 400 in receiving or transmitting ultrasonic waves, thus affecting the overall performance of the ultrasonic transducer. Optimizing the shape and bonding position of the metal shell 100 and shell 300, specifically through the support step 310, can mitigate this impact. The adhesive mounting flange 102 provides a single-point connection, avoiding thermal stress loops. This effectively reduces the curing stress generated by the adhesive, which is transmitted to the bottom wall of the barrel-shaped body 101 of the metal shell 100. Consequently, the stress on the piezoelectric element 200 and the sound matching element 400 located on the bottom wall of the metal shell 100 is reduced. Therefore, when the ultrasonic transducer operates in complex environments with large temperature and humidity variations, the stress between the metal shell 100 and the outer shell 300 mainly acts at the adhesive joint and is rarely transmitted to the piezoelectric element 200 and the sound matching element 400 on the bottom wall of the metal shell 100 and its barrel-shaped body 101. This improves the measurement accuracy of the ultrasonic transducer.

[0050] Furthermore, the internal stress generated in the metal shell 100 reduces the flatness of the bottom wall of the barrel-shaped body 101 of the metal shell 100. The change in flatness reduces the bonding reliability of the piezoelectric element 200 and the sound matching component 400 on the bottom wall of the metal shell 100 and the barrel-shaped body 101. By optimizing the shape and bonding position of the metal shell 100 and the outer shell 300, that is, by bonding the support step 310 to the mounting protrusion 102, the curing stress generated by the adhesive can be effectively reduced and transferred to the bottom wall of the barrel-shaped body 101 of the metal shell 100. This ensures that the flatness of the bottom wall of the barrel-shaped body 101 of the metal shell 100 meets the requirements, and the bonding reliability of the piezoelectric element 200 and the sound matching component 400 on the bottom wall of the metal shell 100 and the barrel-shaped body 101 is guaranteed.

[0051] like Figure 1 As shown, the height between the lower end face of the mounting flange 102 and the inner bottom wall of the barrel-shaped body 101 is h. The inner bottom wall of the barrel-shaped body 101 is circular with an inner diameter of d, where h ≥ ¼ * d. This design provides sufficient space for the vibration of the metal shell 100.

[0052] like Figure 1As shown, a metal shell 100 is fitted inside the cylindrical body 301, and a first buffer gap 303 exists between the side wall of the cylindrical body 301 and the side wall of the barrel-shaped body 101. The shell 300 can be made of commonly used plastics or composite materials. In this way, the damping characteristics of the shell 300 can be used to absorb residual vibration energy.

[0053] For example, such as Figure 4 As shown, the size of the first buffer gap 303 is L, and the wall thickness of the barrel-shaped body 101 is H, where L ≥ H * 10%. Thus, when the sidewall of the barrel-shaped body 101 vibrates radially under the influence of the piezoelectric element 200, there is no interference between the sidewall of the barrel-shaped body 101 and the sidewall of the outer shell 300. The radial vibration of the sidewall of the barrel-shaped body 101 is not transmitted to the sidewall of the outer shell 300, effectively reducing the resonance of the outer shell 300, thereby effectively eliminating noise vibration and improving the measurement accuracy of the ultrasonic transducer.

[0054] The ultrasonic transducer and ultrasonic flowmeter provided in this application embodiment have a first buffer gap 303 between the side wall of the cylindrical body 301 of the outer shell 300 and the side wall of the barrel-shaped body 101 of the metal shell 100. Air is diffused within the first buffer gap 303. An acoustic impedance abrupt change interface is formed between the air and the side wall of the cylindrical body 301, and between the air and the side wall of the barrel-shaped body 101, which can reflect most of the vibration energy. Thus, when the piezoelectric element 200 receives an electrical signal and vibrates, most of the radial vibration of the piezoelectric element 200 along the metal shell 100 cannot be transmitted to the side wall of the outer shell 300 due to the presence of the first buffer gap 303. This effectively reduces the resonance of the outer shell 300, thereby effectively eliminating noise vibration and improving the measurement accuracy of the ultrasonic transducer. Furthermore, the presence of the first buffer gap 303 also allows the metal shell 100 and the outer shell 300 to expand freely when there are large changes in temperature and humidity, avoiding mutual interference between the metal shell 100 and the outer shell 300 and reducing the measurement accuracy of the ultrasonic transducer.

[0055] like Figure 1 and Figure 4 As shown, the outer casing 300 also includes an annular flange 304, which is disposed at one end of the cylindrical body 301 and extends inward relative to the side wall of the cylindrical body 301. The annular flange 304 is disposed opposite to the edge portion of the bottom wall of the cylindrical body 101, and a second buffer gap 305 exists between the annular flange 304 and the bottom wall of the cylindrical body 101. The second buffer gap 305 is connected to the first buffer gap 303.

[0056] In the above embodiment, air is filled between the second buffer gaps 305. An acoustic impedance abrupt change interface is formed between the air and the bottom wall of the annular convex edge 304, and between the air and the bottom wall edge of the barrel-shaped body 101. This interface can reflect most of the vibration energy. Thus, when the piezoelectric element 200 receives an electrical signal and vibrates, the radial vibration component transmitted by the piezoelectric element 200 to the bottom wall edge of the barrel-shaped body 101 is mostly unable to be transmitted to the bottom wall of the annular convex edge 304 due to the presence of the second buffer gaps 305, nor can it be transmitted from the bottom wall of the annular convex edge 304 to the side wall of the outer shell 300. This effectively reduces the resonance of the outer shell 300, thereby effectively eliminating noise vibration and improving the measurement accuracy of the ultrasonic transducer.

[0057] like Figure 1 As shown, the outer wall of the sound matching component 400 is disposed opposite to the inner wall of the annular protrusion 304. The outer wall of the sound matching component 400 is the outer peripheral side wall surface. The inner wall of the annular protrusion 304 refers to the side wall surface of the hollow area enclosed by the annular protrusion 304, which is an annular side wall surface. There is a third buffer gap 306 between the inner wall of the annular protrusion 304 and the side wall of the sound matching component 400. The third buffer gap 306 is connected to the second buffer gap 305.

[0058] In the above embodiment, air is filled between the third buffer gaps 306. Between the air and the inner wall of the annular convex edge 304, and between the air and the side wall of the sound matching component 400, an acoustic impedance abrupt change interface is formed, which can reflect most of the vibration energy. Thus, when the piezoelectric element 200 receives an electrical signal and vibrates, the radial vibration component of the piezoelectric element 200 transmitted to the sound matching component 400 through the bottom wall of the barrel-shaped body 101 cannot be transmitted to the inner wall of the annular convex edge 304 due to the presence of the third buffer gaps 306, nor can it be transmitted from the inner wall of the annular convex edge 304 to the side wall of the outer shell 300. In this way, the resonance of the outer shell 300 can be effectively reduced, thereby effectively eliminating noise vibration and improving the measurement accuracy of the ultrasonic transducer.

[0059] like Figure 1 As shown, in one embodiment, the ultrasonic transducer further includes a shock absorber 500, which includes a first shock absorber ring 501 and a second shock absorber ring 502. The first shock absorber ring 501 is disposed at one end of the second shock absorber ring 502, and the first shock absorber ring 501 protrudes along the edge of the second shock absorber ring 502 toward the outer side wall of the second shock absorber ring 502.

[0060] Correspondingly, such as Figure 1 As shown, the outer diameter of the first segment 307 is smaller than the outer diameter of the second segment 308. The first segment 307 is located at one end of the second segment 308. A boss 309 is formed between the first segment 307 and the second segment 308. The boss 309 is located outside the cylindrical body 301.

[0061] In this embodiment, the first damping ring 501 is fitted to the outer wall of the first segment 307, and the second damping ring 502 is fitted to the stepped surface of the boss 309. In this implementation, the damping element 500 is in direct contact with the outer casing 300, but not with the metal casing 100. Therefore, the damping element 500 will not interfere with the ability of the sound matching layer on the metal casing 100 to receive or transmit ultrasonic waves, while absorbing vibrations of the outer casing 300.

[0062] like Figure 1 As shown, the cylindrical body 301 also includes a cylindrical third section 311. The inner diameter of the third section 311 is larger than the inner diameter of the second section 308. The third section 311 is located at the other end of the second section 308 away from the first section 307. An installation step 312 is formed between the third section 311 and the second section 308. The installation step 312 is annular.

[0063] like Figure 1 As shown, the ultrasonic transducer also includes a back plate 600, which is disposed on the mounting step 312 and covers the opening of the cylindrical body 301 away from the bottom wall of the barrel-shaped body 101. The back plate 600 can be fixed to the mounting step 312 of the housing 300 by adhesive bonding. The material of the back plate 600 can be the same as that of the housing 300, such as plastic or composite materials. The back plate 600 is provided to protect the metal shell 100 disposed inside the housing 300 and the piezoelectric element 200 disposed on the metal shell 100, while increasing the stability of the overall structure. In addition, the back plate 600 can also absorb excess vibration and reduce reverberation interference.

[0064] This application also provides an ultrasonic flow meter that includes the ultrasonic transducer described above. Because the ultrasonic flow meter provided in this application uses the ultrasonic transducer described above, it has the same beneficial effects as the ultrasonic transducer described above.

[0065] The ultrasonic flow meter provided in this application can be used to measure the flow rate and velocity of gases such as natural gas, liquefied gas, blast furnace gas, and coke oven gas, and can also be used to measure the flow rate and velocity of liquids such as hot water in heating networks and oil in oil pipelines.

[0066] The ultrasonic transducer and ultrasonic flow meter provided in this application reduce reverberation, ensuring the purity of the ultrasonic signal and improving signal accuracy; they also reduce the impact of temperature and humidity changes on components, enhancing environmental adaptability; and they optimize stress distribution, reducing performance degradation under harsh environments and extending service life.

[0067] Finally, it should be noted that other embodiments of this utility model will readily occur to those skilled in the art upon consideration of the specification and practice of the utility model disclosed herein. This utility model is intended to cover any variations, uses, or adaptations of this utility model that follow the general principles of this utility model and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this utility model is limited only by the appended claims.

Claims

1. An ultrasonic transducer, characterized in that, include: The metal shell (100) includes a barrel-shaped body (101) and a mounting part, the mounting part being disposed at the open end of the barrel-shaped body (101); A piezoelectric element (200) is attached to the inner bottom wall of the barrel-shaped body (101); The outer casing (300) includes a cylindrical body (301) and a connecting part (302). The connecting part (302) is disposed on the cylindrical body (301) and connected to the mounting part. The metal shell (100) is fitted inside the cylindrical body (301), and a first buffer gap (303) exists between the side wall of the cylindrical body (301) and the side wall of the barrel body (101).

2. The ultrasonic transducer according to claim 1, characterized in that, The outer casing (300) also includes an annular flange (304), which is disposed at one end of the cylindrical body (301) and extends inward relative to the side wall of the cylindrical body (301). There is a second buffer gap (305) between the annular protrusion (304) and the bottom wall of the barrel-shaped body (101), and the second buffer gap (305) and the first buffer gap (303) are connected.

3. The ultrasonic transducer according to claim 2, characterized in that, The ultrasonic transducer also includes: A sound matching component (400) is attached to the outer bottom wall of the barrel-shaped body (101), and the outer side wall of the sound matching component (400) is opposite to the inner side wall of the annular protrusion (304). There is a third buffer gap (306) between the inner wall of the annular protrusion (304) and the outer wall of the sound matching component (400), and the third buffer gap (306) is connected to the second buffer gap (305).

4. The ultrasonic transducer according to claim 3, characterized in that, The inner bottom wall of the barrel-shaped body (101) is circular, and the diameter of the inner bottom wall is d; The transition radius between the side wall and the bottom wall of the barrel-shaped body (101) is R; The sound matching component (400) has a circular structure and a diameter of D. Where D≤d-2R.

5. The ultrasonic transducer according to any one of claims 1-4, characterized in that, The first buffer gap (303) has a size of L, and the wall thickness of the barrel-shaped body (101) is H, wherein L ≥ H * 10%.

6. The ultrasonic transducer according to any one of claims 1-4, characterized in that, The mounting part is a mounting flange (102) provided at the open end of the barrel-shaped body (101), and the mounting flange (102) extends outward relative to the side wall of the barrel-shaped body (101). The cylindrical body (301) includes a cylindrical first section (307) and a cylindrical second section (308). The inner diameter of the first section (307) is smaller than the inner diameter of the second section (308). A support step (310) is also formed between the first section (307) and the second section (308). The support step (310) is located inside the cylindrical body (301) and constitutes the connecting part (302). The support step (310) connects to and supports the mounting flange (102).

7. The ultrasonic transducer according to claim 6, characterized in that, The ultrasonic transducer also includes: The shock absorber (500) includes a first shock absorber ring (501) and a second shock absorber ring (502). The first shock absorber ring (501) is disposed at one end of the second shock absorber ring (502), and the first shock absorber ring (501) protrudes along the edge of the second shock absorber ring (502) toward the outer side wall of the second shock absorber ring (502). The outer diameter of the first segment (307) is smaller than the outer diameter of the second segment (308). The first segment (307) is disposed at one end of the second segment (308). A boss (309) is formed between the first segment (307) and the second segment (308). The boss (309) is located outside the cylindrical body (301). The first shock-absorbing ring (501) is fitted to the outer wall of the first segment (307), and the second shock-absorbing ring (502) is fitted to the stepped surface of the boss (309).

8. The ultrasonic transducer according to claim 6, characterized in that, The height between the lower end face of the mounting flange (102) and the inner bottom wall of the barrel-shaped body (101) is h. The inner bottom wall of the barrel-shaped body (101) is circular and has an inner diameter of d, where h ≥ ¼ * d.

9. The ultrasonic transducer according to claim 6, characterized in that, The cylindrical body (301) further includes a cylindrical third section (311), the inner diameter of which is larger than the inner diameter of the second section (308), the third section (311) is disposed at the other end of the second section (308) away from the first section (307), and an installation step (312) is formed between the third section (311) and the second section (308). The ultrasonic transducer also includes: A back plate (600) is disposed on the mounting step (312) and covers the opening of the cylindrical body (301) near the piezoelectric element (200).

10. An ultrasonic flow meter, characterized in that, Includes the ultrasonic transducer according to any one of claims 1-9.

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