Metal housing for transducer, ultrasonic transducer, and ultrasonic flow meter

Abstract

The utility model relates to the technical field of gas flow measurement, and discloses a metal shell for a transducer, an ultrasonic transducer and an ultrasonic flowmeter, the metal shell for the transducer comprises a top wall and a side wall connected to the edge of the top wall, a first cambered surface is formed at the bending position between the top wall and the side wall, and a second cambered surface is formed at the bending position between the top wall and the side wall. The joint of the plane where the top wall is located and the first arc face is staggered to form a first offset part. According to the metal shell for the transducer, the first cambered surface is formed at the bent part between the top wall and the side wall, and the joint of the plane where the top wall is located and the first cambered surface is arranged in a staggered manner, so that the first offset part is formed, and the first offset part can release most residual processing stress, so that processing stress residues are reduced, and the service life of the transducer is prolonged. And residual stress is prevented from being transmitted to the plane where the top wall is located, formation of high planeness of the plane of the metal shell is promoted, the precision and sensitivity of the ultrasonic transducer are guaranteed, and the service life of the ultrasonic transducer is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of gas flow measurement technology, and in particular to a metal housing for a transducer, an ultrasonic transducer, and an ultrasonic flow meter. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] Ultrasonic gas flow meters are gradually replacing traditional mechanical gas flow meters due to their advantages such as good stability, high measurement accuracy, wide range, low maintenance rate, low pressure loss, and convenient installation. As the core component of ultrasonic gas flow meters, the performance and reliability of the ultrasonic transducer directly affect the metering accuracy of the gas flow meter.

[0004] In related technologies, the outer shell of an ultrasonic transducer is a metal shell, which is usually manufactured by stamping or machining. In traditional stamping or machining, certain processing stress is formed inside the metal shell. Excessive residual processing stress can cause the metal shell to deform within a certain range. The deformation of the metal parts can significantly affect the accuracy, sensitivity and service life of the components. Utility Model Content

[0005] The purpose of this invention is to at least solve the problem of deformation caused by processing stress inside a metal shell during stamping or machining. This purpose is achieved through the following technical solution:

[0006] The first aspect of this utility model provides a metal housing for a transducer, comprising:

[0007] The top wall and the side wall connected to the edge of the top wall, the bend between the top wall and the side wall forms a first arc surface, and the connection between the plane of the top wall and the first arc surface is offset to form a first discontinuity.

[0008] The metal housing of the transducer of this utility model forms a first arc surface at the bend between the top wall and the side wall, and the connection between the top wall and the first arc surface is misaligned to form a first discontinuity. By setting the first discontinuity in stress concentration areas such as the bend, most of the residual processing stress can be released, the residual processing stress can be reduced, and the transmission of residual stress to the plane where the top wall is located can be blocked. This promotes the formation of a higher flatness of the plane where the top wall is located, so as to ensure the accuracy and sensitivity of the ultrasonic transducer and extend its service life.

[0009] In addition, the metal housing for the transducer according to this utility model may also have the following additional technical features:

[0010] In some embodiments of this utility model, the first discontinuity extends downward from the upper edge of the top wall to the upper edge of the first arc surface, and the height of the first discontinuity is less than the thickness of the top wall.

[0011] In some embodiments of this utility model, the outer periphery of the connection between the top wall and the first arc surface has a first upper step portion, and the inner periphery of the connection between the top wall and the first arc surface has a first lower step portion. Along the longitudinal direction, the first upper step portion and the first lower step portion are aligned, and the first discontinuity portion is formed between the first upper step portion and the first lower step portion.

[0012] In some embodiments of this utility model, the height of the first discontinuity is a, the thickness of the top wall is b, and 30%b≤a.

[0013] In some embodiments of this utility model, the metal housing further includes a bottom wall, which is disposed at the end of the side wall away from the top wall and surrounds the outside of the side wall along an arrangement direction perpendicular to the bottom wall to the top wall.

[0014] In some embodiments of this utility model, a second arc surface is formed at the bend between the bottom wall and the side wall, and the connection between the plane where the bottom wall is located and the second arc surface is offset to form a second discontinuity, the height of the second discontinuity being less than the thickness of the bottom wall.

[0015] In some embodiments of this utility model, the second discontinuity extends upward from the upper edge of the bottom wall to the upper edge of the second arc surface;

[0016] The vertical height of the second arc surface is d, and 30% d ≤ c.

[0017] A second aspect of this invention provides an ultrasonic transducer comprising a piezoelectric element, a matching layer, and a metal housing for the transducer as described in any of the preceding claims, wherein the piezoelectric element and the matching layer are connected to the top wall.

[0018] In some embodiments of this utility model, the ultrasonic transducer further includes a backing, which includes a first backing covering the periphery of the side wall and a second backing covering the outer side of the bottom wall, wherein the end face of the first backing away from the bottom wall is flush with the end face of the top wall.

[0019] A third aspect of this utility model provides an ultrasonic flow meter, comprising a meter body and an ultrasonic transducer as described in any of the preceding claims, wherein the ultrasonic transducer is disposed within the meter body. Attached Figure Description

[0020] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0021] Figure 1 A schematic diagram of the structure of an ultrasonic transducer according to an embodiment of the present invention is shown.

[0022] Figure 2 A schematic diagram of the structure of a metal housing for a transducer according to an embodiment of the present invention is shown from a first perspective.

[0023] Figure 3 A schematic diagram of the structure of a metal housing for a transducer according to an embodiment of the present invention is shown from a second perspective.

[0024] Figure 4 A schematic diagram of the structure of a metal housing for a transducer according to an embodiment of the present invention is shown from a third-view perspective.

[0025] Figure 5 for Figure 4 Enlarged view of point A in the middle;

[0026] Figure 6 for Figure 4 Enlarged view of point B in the middle.

[0027] The attached figures are labeled as follows:

[0028] 1. Metal shell; 11. Top wall; 12. Side wall; 13. First arc surface; 14. First discontinuity section; 141. First upper step section; 142. First lower step section; 15. Bottom wall; 16. Second arc surface; 17. Second discontinuity section; 171. Second upper step section; 172. Second lower step section;

[0029] 2. Backing; 21. First backing; 22. Second backing;

[0030] 3. Piezoelectric elements;

[0031] 4. Matching layer;

[0032] 5. Sealing element; 51. Sealing plate. Detailed Implementation

[0033] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0034] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0035] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0036] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations.

[0037] In related technologies, the core components of ultrasonic transducers typically include a piezoelectric layer, a metal shell, a matching layer, and a backing. The vibration of the piezoelectric layer generates ultrasonic waves, which are transmitted to the fluid through the metal shell and matching layer. The metal shell is usually manufactured through stamping or machining. Metal components used in electronic components such as sensors typically require smaller and more precise dimensions. Stamping or machining methods often present the following problems: In electronic components such as sensors, the metal shell, as a supporting component, typically requires precise dimensions and minimal deformation; in traditional stamping or machining, which involves stretching or bending, certain processing stresses are created within the metal component. Excessive residual processing stress can lead to deformation within a certain range. Transducers and other components have high dimensional requirements for the metal shell, which plays a supporting, transmitting, and fixing role; localized deformation can easily lead to functional failure.

[0038] In view of this, this embodiment provides a metal housing for a transducer, which aims to reduce residual processing stress and block the transmission of residual stress to the plane where the top wall 11 is located by staggering the connection between the top wall 11 and the first arc surface 13 to form a first discontinuity 14, thereby ensuring that the metal housing 1 has accurate dimensions and minimal deformation, thus solving the above-mentioned technical problems.

[0039] like Figures 1 to 6 As shown, according to an embodiment of the present invention, a metal housing for a transducer is proposed. The metal housing for the transducer is used in an ultrasonic transducer, which further includes a piezoelectric element 3 and a matching layer 4.

[0040] The metal shell 1 includes a top wall 11 and a side wall 12 connected to the edge of the top wall 11. A first arc surface 13 is formed at the bend between the top wall 11 and the side wall 12. The connection between the plane where the top wall 11 is located and the first arc surface 13 is offset to form a first discontinuity 14. The metal shell 1 serves as a supporting and fixed frame. Its top wall 11 is usually fixed with piezoelectric elements and matching layers by an adhesive bonding process.

[0041] The side wall 12 surrounds the edge of the top wall 11. The connection between the top wall 11 and the side wall 12 is set as an arc transition connection. The extension direction of the side wall 12 is perpendicular to the plane of the top wall 11. The metal shell 1 is cylindrical and has a cavity inside. The piezoelectric element 3 is disposed in the cavity and connected to the top wall 11. The piezoelectric element 3 is bonded to the top wall 11 through the first adhesive layer.

[0042] The piezoelectric element 3 is a circular cylinder that generates ultrasonic vibrations and is made of piezoelectric ceramics, piezoelectric single crystals or similar materials.

[0043] A first adhesive layer is coated between the piezoelectric element 3 and the inner side of the top wall 11, and the piezoelectric element 3 and the top wall 11 are bonded together by the first adhesive layer. The bonding process is usually carried out in a high-temperature environment. In related technologies, the high-temperature process can cause the release of internal stress in the metal shell, resulting in deformation and thus affecting the bonding effect.

[0044] In contrast, in this embodiment, by providing the first discontinuity portion 14, stress can be directly released during the stamping process, reducing stress release during the bonding and curing process, avoiding weakening of bonding strength due to stress release, and ensuring bonding strength.

[0045] Since the piezoelectric element 3 has a first electrode layer and a second electrode layer at its two ends respectively, and the first electrode layer is connected to the metal shell 1, and the metal shell 1 and the first electrode layer need to be conductive, the thickness of the first adhesive layer is very thin and cannot affect the conductivity between the metal shell 1 and the first electrode layer. Alternatively, the first adhesive layer can be a conductive adhesive layer.

[0046] Both the first and second electrode layers are silver electrodes, which have good conductivity.

[0047] Matching layer 4 is connected to the side of top wall 11 away from piezoelectric element 3, and matching layer 4 is bonded to top wall 11 through second adhesive layer.

[0048] Matching layer 4, also called acoustic matching layer 4, is usually composed of resin and glass microspheres. Matching layer 4 is used to transmit ultrasonic waves to a gas or receive ultrasonic waves propagating through the gas, so that the mechanical vibration of the piezoelectric element 3 excited by the driving AC voltage can be effectively transmitted as ultrasonic waves through the external medium, and the input ultrasonic waves can be effectively converted into voltage.

[0049] A second adhesive layer is applied between the matching layer 4 and the top wall 11, and the matching layer 4 is bonded to the top wall 11 through the second adhesive layer.

[0050] The metal housing for the transducer of this utility model forms a first arc surface 13 at the bend between the top wall 11 and the side wall 12, and the connection between the top wall 11 and the first arc surface 13 is misaligned to form a first discontinuity 14. By setting the first discontinuity 14 in stress concentration areas such as the bend between the top wall 11 and the side wall 12, most of the residual processing stress can be released, the residual processing stress can be reduced, and the residual stress can be blocked from being transmitted to the plane where the top wall 11 is located. This promotes the formation of a higher flatness of the plane where the top wall 11 is located, ensuring that the metal housing 1 has accurate dimensions and minimal deformation, thereby improving the accuracy and sensitivity of the ultrasonic transducer and extending its service life.

[0051] In some embodiments of this invention, the first discontinuity portion 14 extends downward from the upper edge of the top wall 11 to the upper edge of the first arc surface 13, and the height of the first discontinuity portion 14 is less than the thickness of the top wall 11. Specifically, the extension direction of the first discontinuity portion 14 is perpendicular to the plane of the top wall 11, the height of the first discontinuity portion 14 is a, the thickness of the top wall 11 is b, and 30%b≤a. By providing the first discontinuity portion 14, the shrinkage stress can be blocked from being transmitted to the plane of the top wall 11, and the internal stress can be released to a certain extent through the shearing and stamping process.

[0052] In some embodiments of this utility model, the outer periphery of the connection between the top wall 11 and the first arc surface 13 has a first upper step portion 141, and the inner periphery of the connection between the top wall 11 and the first arc surface 13 has a first lower step portion 142. Along the longitudinal direction, the first upper step portion 141 and the first lower step portion 142 are aligned, and a first discontinuity portion is formed between the first upper step portion 141 and the first lower step portion 142.

[0053] It is understood that the longitudinal direction is the extension direction of the first discontinuity portion 14. The first upper step portion 141 includes a first connecting surface and a second connecting surface that intersect each other, wherein the first connecting surface is on the same plane as the plane containing the upper edge of the top wall 11, and the second connecting surface is perpendicular to the first connecting surface. The first lower step portion 142 includes a third connecting surface and a fourth connecting surface that intersect each other, wherein the third connecting surface is on the same plane as the plane containing the lower edge of the top wall 11, the fourth connecting surface is perpendicular to the third connecting surface, and the second connecting surface and the fourth connecting surface are aligned in the longitudinal direction.

[0054] In some embodiments of this utility model, the metal housing 1 further includes a bottom wall 15, which is disposed at the end of the side wall 12 away from the top wall 11 and is arranged in a direction perpendicular to the bottom wall 15 to the top wall 11. The bottom wall 15 surrounds the outside of the side wall 12 and is used to fix and support the cylinder formed by the top wall 11 and the side wall 12.

[0055] In this embodiment, the bottom wall 15 is a ring-shaped planar structure. In other embodiments, the bottom wall 15 may also be square or any other polygon.

[0056] In related technologies, the vibration of the piezoelectric element 3 is often transmitted through the metal shell, which in turn generates reverberation and affects accuracy.

[0057] In contrast, in this embodiment, a second arc surface 16 is formed at the bend between the bottom wall 15 and the side wall 12, and the connection between the plane of the bottom wall 15 and the second arc surface 16 is offset to form a second discontinuity 17. By providing the second discontinuity 17 in stress concentration areas such as the bend between the bottom wall 15 and the side wall 12, most of the residual processing stress can be released, reducing residual processing stress.

[0058] In some embodiments of this utility model, the second discontinuity portion 17 extends upward from the upper edge of the bottom wall 15 to the upper edge of the second arc surface 16. The connection between the bottom wall 15 and the side wall 12 is set as an arc-shaped transition connection. The extension direction of the bottom wall 15 is parallel to the extension direction of the top wall 11, and the extension direction of the second discontinuity portion 17 is perpendicular to the plane where the bottom wall 15 is located.

[0059] In some embodiments of this utility model, the outer periphery of the connection between the bottom wall 15 and the second arc surface 16 has a second upper step portion 171, and the inner periphery of the connection between the bottom wall 15 and the second arc surface 16 has a second lower step portion 172. Along the longitudinal direction, the second upper step portion 171 and the second lower step portion 172 are aligned, and a second discontinuity portion 17 is formed between the second upper step portion 171 and the second lower step portion 172.

[0060] It is understood that the longitudinal direction is the extension direction of the second discontinuity portion 17. The second upper step portion 171 includes a fifth connecting surface and a sixth connecting surface that intersect each other, wherein the fifth connecting surface is on the same plane as the plane containing the upper edge of the bottom wall 15, and the sixth connecting surface is perpendicular to the fifth connecting surface. The second lower step portion 172 includes a seventh connecting surface and an eighth connecting surface that intersect each other, wherein the seventh connecting surface is on the same plane as the plane containing the lower edge of the bottom wall 15, the eighth connecting surface is perpendicular to the seventh connecting surface, and the sixth connecting surface and the eighth connecting surface are aligned in the longitudinal direction.

[0061] The height of the second discontinuity section 17 is c, and the vertical height of the second arc surface 16 is d, where 30% d ≤ c. By setting the second discontinuity section 17, the contraction stress can be blocked from being transmitted to the plane of the bottom wall 15. A first discontinuity section 14 is set at the connection between the top wall 11 and the first arc surface 13, and a second discontinuity section 17 is set at the connection between the bottom wall 15 and the second arc surface 16. The first discontinuity section 14 provides initial resistance to vibration transmission, while the second discontinuity section 17 provides enhanced resistance. The double-layer structure hinders the transmission of excess vibration, thus providing better resistance and improving the resistance to vibration transmission.

[0062] Table 1 below shows the average flatness values ​​of the top wall 11 and the bottom wall 15 under the two conditions of no discontinuity and with discontinuity.

[0063] Table 1:

[0064] No discontinuity Discontinuity Average flatness α of top wall Average flatness α / 2 of the top wall Average flatness β of bottom wall Average flatness of bottom wall β / 2

[0065] As shown in Table 1, after stress relief and blocking, both the top wall 11 and the bottom wall 15 have better flatness dimensions.

[0066] The ultrasonic transducer also includes a backing 2, which is a sound-absorbing structure. Its function is to increase the damping of the transducer's vibration system and accelerate the elimination of the transducer's aftershocks. It is usually made of materials such as epoxy resin, polyurethane, or polyamide, and is bonded to piezoelectric ceramics through processes such as bonding, potting, or injection molding.

[0067] In related technologies, the backing 2 is usually fixed to the metal shell by injection molding. There is often an extremely thin area where the plane of the top wall 11 is tangent to the first arc surface 13, which results in poor adhesion of the backing 2 near the first arc surface 13, making it easy for the backing 2 to detach from the metal shell 1.

[0068] In contrast, in this embodiment, the backing 2 includes a first backing 21 covering the periphery of the sidewall 12 and a second backing 22 covering the outer side of the bottom wall 15, with the end face of the first backing 21 facing away from the bottom wall 15 flush with the end face of the top wall 11. By providing a first break portion 14 at the tangent point between the top wall 11 and the first arc surface 13, and with the end face of the first backing 21 facing away from the bottom wall 15 flush with the end face of the top wall 11, the above structure increases the covering strength of the first backing 21. The first break portion 14 is formed at a height a at the point where the first backing 21 is prone to detachment, and the first break portion 14 maintains a certain height, increasing the covering size of the first backing 21, improving its covering strength and adhesion, and reducing the possibility of the backing 2 detaching.

[0069] In some embodiments of this utility model, the ultrasonic transducer further includes a sealing element 5, which is connected to the side wall 12 and is used to seal the cavity.

[0070] In this embodiment, the sealing element 5 includes a sealing plate 51, which is fixedly connected to the bottom wall 15. The cavity inside the metal housing 1 is filled with inert gases such as nitrogen, which can prevent damage to internal components due to electrode corrosion and improve the stability and reliability of the ultrasonic transducer.

[0071] The second aspect of this invention provides an ultrasonic transducer, comprising a piezoelectric element 3, a matching layer 4, and the aforementioned metal housing 1 for the transducer. The specific structure of the ultrasonic transducer is described above and will not be repeated here.

[0072] The third aspect of this utility model provides an ultrasonic flow meter, including a meter body and the aforementioned ultrasonic transducer, wherein the ultrasonic transducer is disposed within the meter body to measure the flow rate of the gas medium flowing through the ultrasonic gas flow meter.

[0073] It should be noted that the arrangement of the ultrasonic transducer within the meter body can be found in the structure of gas ultrasonic flow meters in related technologies, and will not be further elaborated in the embodiments of this application.

[0074] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A metal housing for a transducer, characterized in that, include: The top wall and the side wall connected to the edge of the top wall, the bend between the top wall and the side wall forms a first arc surface, and the connection between the plane of the top wall and the first arc surface is offset to form a first discontinuity.

2. The metal housing for the transducer according to claim 1, characterized in that, The first discontinuity extends downward from the upper edge of the top wall to the upper edge of the first arc surface, and the height of the first discontinuity is less than the thickness of the top wall.

3. The metal housing for the transducer according to claim 1, characterized in that, The outer periphery of the connection between the top wall and the first arc surface has a first upper step portion, and the inner periphery of the connection between the top wall and the first arc surface has a first lower step portion. Along the longitudinal direction, the first upper step portion and the first lower step portion are aligned, and the first discontinuity portion is formed between the first upper step portion and the first lower step portion.

4. The metal housing for the transducer according to claim 1, characterized in that, The height of the first discontinuity is a, and the thickness of the top wall is b, where 30%b≤a.

5. The metal housing for a transducer according to any one of claims 1 to 4, characterized in that, The metal housing also includes a bottom wall, which is disposed at the end of the side wall away from the top wall and surrounds the outside of the side wall along an arrangement direction perpendicular to the bottom wall to the top wall.

6. The metal housing for a transducer according to claim 5, characterized in that, A second arc surface is formed at the bend between the bottom wall and the side wall. The connection between the plane of the bottom wall and the second arc surface is offset to form a second discontinuity. The height of the second discontinuity is less than the thickness of the bottom wall.

7. The metal housing for a transducer according to claim 6, characterized in that, The second discontinuity extends upward from the upper edge of the bottom wall to the upper edge of the second arc surface; The height of the second discontinuity is c, and the vertical height of the second arc surface is d, where 30% d ≤ c.

8. An ultrasonic transducer comprising a piezoelectric element, a matching layer, and a metal housing for the transducer as described in any one of claims 1 to 7, wherein the piezoelectric element and the matching layer are connected to the top wall.

9. The ultrasonic transducer according to claim 8, characterized in that, The ultrasonic transducer also includes a backing, which includes a first backing covering the periphery of the side wall and a second backing covering the outer side of the bottom wall, wherein the end face of the first backing away from the bottom wall is flush with the end face of the top wall.

10. An ultrasonic flow meter, characterized in that, It includes a body and an ultrasonic transducer as described in claim 8 or 9, wherein the ultrasonic transducer is disposed within the body of the body.

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