An ultrasonic detection sensor

Abstract

This utility model discloses an ultrasonic detection sensor, including a first detection unit and a second detection unit. The inner wall of the first detection unit has a first recessed structure, and the inner wall of the second detection unit has a second recessed structure. The first detection unit has a first detection surface, and the second detection unit has a second detection surface. The first detection surface and the second detection surface are opposite to each other and spaced apart, and the first detection surface and the second detection surface together form a detection space. A first piezoelectric element is disposed inside the first detection unit, and a second piezoelectric element is disposed inside the second detection unit. It also includes a circuit board, which is connected to the first piezoelectric element via a first wire passing through the first recessed structure, and to the second piezoelectric element via a second wire passing through the second recessed structure. This design can detect whether there are air bubbles in the liquid inside a tubular object to be tested, and can also detect the water level inside the liquid container. Furthermore, it avoids the two wires being squeezed.

Description

Technical Field

[0001] This utility model relates to the field of ultrasonic testing technology, specifically to an ultrasonic testing sensor. Background Technology

[0002] When a liquid flows through a pipe, if the local pressure drops below the liquid's saturated vapor pressure, tiny bubbles will rapidly form. These bubbles, carried by the fluid to high-pressure areas, will burst instantly, generating extremely strong shock waves. Ultrasonic detection devices can monitor the presence of bubbles in the pipe in real time, allowing operators to adjust the system pressure promptly (e.g., increasing the inlet pressure or reducing the flow rate) to prevent the pressure from falling below the saturated vapor pressure, thus fundamentally preventing cavitation.

[0003] Patent document CN223091342U discloses a novel side-mounted transducer ultrasonic water meter, which specifically discloses that it includes an ultrasonic tube section, a set of transducer sleeves obliquely and symmetrically arranged on the side wall of the ultrasonic tube section, a plug rod embedded in the transducer sleeve, a transducer assembly embedded in the plug rod, a junction box for installing an adapter plate and a battery for power supply in the inner cavity of the water meter housing, an electrical box for installing a circuit board on the top of the water meter housing, a wide-screen transparent bracket on the top of the electrical box, a housing cover on the wide-screen transparent bracket, and the transducer assembly is connected to the adapter plate for signal connection.

[0004] The aforementioned patent addresses the problem in existing ultrasonic water meters where the transducer is mounted at the top of the pipe section, causing the ultrasonic signal emitted by the top transducer to be affected by air bubbles, resulting in inconsistent ultrasonic signal transmission through the medium during measurement. However, it does not solve the problem of the conductive wire being squeezed when the conductive wire is connected to the two electrode surfaces of the circuit board and the piezoelectric ceramic respectively, thus requiring improvement. Utility Model Content

[0005] To address the problems existing in the prior art, the purpose of this utility model is to provide an ultrasonic detection sensor that can detect bubbles and water levels while preventing the conductive wires connecting the circuit board and the two electrode surfaces of the piezoelectric ceramic from being squeezed.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows:

[0007] An ultrasonic detection sensor includes a first detection part and a second detection part. The inner wall of the first detection part is provided with a first recessed structure, and the inner wall of the second detection part is provided with a second recessed structure. The first detection part has a first detection surface, and the second detection part has a second detection surface. The first detection surface and the second detection surface are opposite to each other and spaced apart, and the first detection surface and the second detection surface together form a detection space. A first piezoelectric element is disposed inside the first detection part, and a second piezoelectric element is disposed inside the second detection part. The sensor also includes a circuit board. One end of a first wire is connected to the circuit board, and the other end of the first wire passes through the first recessed structure and is connected to an electrode surface of the first piezoelectric element. One end of a second wire is connected to the circuit board, and the other end of the second wire passes through the second recessed structure and is connected to an electrode surface of the second piezoelectric element.

[0008] Furthermore, it also includes a substrate, with the first detection unit and the second detection unit respectively disposed on a surface of the substrate, and the interiors of the first detection unit, the second detection unit, and the substrate are connected; the circuit board is disposed inside the substrate.

[0009] Furthermore, the inner wall of the first detection unit is provided with a first protrusion structure, and the first piezoelectric element abuts against the outer wall of the first protrusion structure; the inner wall of the second detection unit is provided with a second protrusion structure, and the second piezoelectric element abuts against the outer wall of the second protrusion structure.

[0010] Furthermore, the number of the first protrusion structure is at least two, the two first protrusion structures are symmetrically arranged, and the first piezoelectric element is disposed between the two first protrusion structures; the number of the second protrusion structure is at least two, the two second protrusion structures are symmetrically arranged, and the second piezoelectric element is disposed between the two second protrusion structures.

[0011] Furthermore, it also includes a sealant, which fills the interior of the first detection part, the interior of the second detection part, and the interior of the substrate, respectively, and the sealant encapsulates the circuit board, the first piezoelectric element, and the second piezoelectric element.

[0012] Furthermore, a mounting hole is provided through the surface of the substrate, a sealing element is provided over the opening of the substrate, and the substrate is connected to the sealing element through the mounting hole.

[0013] Furthermore, the two ends of the first detection unit are connected to the two ends of the second detection unit, and the interior of the first detection unit is connected to the interior of the second detection unit. The circuit board is disposed inside the first detection unit or inside the second detection unit.

[0014] Furthermore, the first detection section and the second detection section are respectively arc-shaped.

[0015] Furthermore, the cross-sectional dimension of the first detection part gradually increases from the middle to both ends, and the cross-sectional dimension of the second detection part gradually increases from the middle to both ends; the first detection surface is located on the inner side of the middle of the first detection part, and the second detection surface is located on the inner side of the middle of the second detection part.

[0016] Furthermore, on a plane parallel to the first detection surface, the projections of the first detection surface and the second detection surface completely or partially overlap.

[0017] Furthermore, the first detection surface is a smooth plane, and the second detection surface is a smooth plane.

[0018] The beneficial effects of this utility model are as follows:

[0019] I. This utility model can detect whether there are air bubbles in the liquid inside the object being tested by placing the object to be tested in the detection space, emitting ultrasonic waves through a first piezoelectric element, and receiving ultrasonic waves through a second piezoelectric element.

[0020] II. This utility model can be installed in a specific liquid container to detect the water level information of the liquid inside the container.

[0021] Third, the present invention provides a first recessed structure on the inner wall of the first detection part and a second recessed structure on the inner wall of the second detection part. On the one hand, it can prevent the first wire connecting the circuit board and the first piezoelectric element from being squeezed, and on the other hand, it can prevent the second wire connecting the circuit board and the second piezoelectric element from being squeezed. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural schematic diagram of an embodiment of the present invention;

[0023] Figure 2 yes Figure 1 A cross-sectional view;

[0024] Figure 3 yes Figure 1 A three-dimensional structural diagram of another type of matrix;

[0025] Figure 4 yes Figure 3 A cross-sectional view;

[0026] Figure 5 yes Figure 3 A schematic diagram of the three-dimensional structure of the matrix;

[0027] Figure 6 This is a three-dimensional structural diagram of the second embodiment of the present invention;

[0028] Figure 7 yes Figure 6 A cross-sectional view.

[0029] Figure Labels

[0030] 100. Ultrasonic detection sensor; 1. First detection part; 11. First recessed structure; 12. First detection surface; 13. First protruding structure; 2. Second detection part; 21. Second recessed structure; 22. Second detection surface; 23. Second protruding structure; 3. Detection space; 4. First piezoelectric element; 5. Second piezoelectric element; 6. Circuit board; 7. Substrate; 71. Mounting hole; 8. Sealant. Detailed Implementation

[0031] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "top surface", "bottom surface", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the position or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In this description of the utility model, "a number" means two or more, unless otherwise explicitly specified.

[0033] In this utility model, unless otherwise explicitly specified and limited, the terms "assembly," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can also refer to a mechanical connection; they can refer to a direct connection or a connection through an intermediate medium; or they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] In this embodiment, "interface" refers to the boundary line or contact surface between two different materials or media.

[0035] The utility model will be further described below with reference to the accompanying drawings and specific embodiments. The following description is merely exemplary and does not limit the scope of protection of the utility model.

[0036] Please refer to Figures 1-5 An ultrasonic detection sensor 100 includes a first detection unit 1 and a second detection unit 2. The inner wall of the first detection unit 1 has a first recessed structure 11, and the inner wall of the second detection unit 2 has a second recessed structure 21. The first detection unit 1 has a first detection surface 12, and the second detection unit 2 has a second detection surface 22. The first detection surface 12 and the second detection surface 22 are opposite to and spaced apart, and the first detection surface 12 and the second detection surface 22 together form a detection space 3. A first piezoelectric element 4 is disposed inside the first detection unit 1, and a second piezoelectric element 5 is disposed inside the second detection unit 2. The sensor also includes a circuit board 6. One end of a first wire (not shown in the figure) is connected to the circuit board 6, and the other end of the first wire passes through the first recessed structure 11 and is connected to an electrode surface of the first piezoelectric element 4. One end of a second wire (not shown in the figure) is connected to the circuit board 6, and the other end of the second wire passes through the second recessed structure 21 and is connected to an electrode surface of the second piezoelectric element 5. The object to be tested (including syringes, oil tubes, and water tubes containing liquid, as well as the liquid itself) is placed in the testing space 3. The first piezoelectric element 4 is used to emit ultrasonic waves. The ultrasonic waves travel through the first testing surface 12, the testing space 3 (acting on the liquid in the syringe, oil tube, or water tube, or directly contacting the liquid), the second testing surface 22, and are finally received by the second piezoelectric element 5.

[0037] In this embodiment, both the first detection surface 12 and the second detection surface 22 are smooth planes. The purpose is that if the first detection surface 12 and the second detection surface 22 are rough and uneven, numerous air bubbles and voids will exist between them when they come into contact with the object to be tested. These air bubbles and voids will become obstacles to the propagation of ultrasonic waves. The smooth first detection surface 12 and the smooth second detection surface 22 can form a large-area, uniform, and tight contact with the object to be tested, thereby avoiding the formation of air bubbles and voids that would affect the detection effect.

[0038] In this embodiment, the ultrasonic detection sensor 100 further includes a substrate 7, which includes, for example, a substrate 7. Figure 1 or Figure 3The system has two structures: a first detection unit 1 and a second detection unit 2 are respectively disposed on one surface of the substrate 7. The first detection unit 1 and the second detection unit 2 can be disposed at the edge of one surface of the substrate 7 or at the center of one surface of the substrate 7; this is not limited here. Furthermore, the interiors of the first detection unit 1, the second detection unit 2, and the substrate 7 are connected. One end of the first recessed structure 11 extends to the connection between the first detection unit 1 and the substrate 7, and one end of the second recessed structure 21 extends to the connection between the second detection unit 2 and the substrate 7. A circuit board 6 is disposed inside the substrate 7, and the circuit board 6 seals the connection between the first detection unit 1 and the substrate 7, and the connection between the second detection unit 2 and the substrate 7.

[0039] Specifically, please refer to Figure 2 and Figure 4 On a plane parallel to the first detection surface 12, the projections of the first detection surface 12 and the second detection surface 22 completely or partially overlap. In a preferred embodiment, the projections of the first detection surface 12 and the second detection surface 22 completely overlap, meaning that the cross-sectional dimensions of the first detection surface 12 and the second detection surface 22 are identical, and the first detection surface 12 and the second detection surface 22 are perfectly aligned. The advantage of this structure is that if the first detection surface 12 and the second detection surface 22 are not aligned, the second detection surface 22 may only receive divergent edge acoustic wave signals. These edge acoustic wave signals are inherently weak, and after attenuation by the object being tested, they are difficult to identify by the time they reach the second piezoelectric element 5, leading to misjudgment. The design of the first detection surface 12 and the second detection surface 22 completely overlapping ensures that the strongest ultrasonic signal can act on the second detection surface 22.

[0040] More specifically, in this embodiment, the cross-sectional dimensions of the first detection unit 1 and the second detection unit 2 are the same, so that when the first detection unit 1 and the second detection unit 2 cooperate to clamp the tubular object to be detected, the pressure on the object to be detected is the same, making the entire clamping process more stable.

[0041] Please refer to the details. Figures 4-5In this embodiment, the inner wall of the first detection unit 1 is provided with a first protrusion structure 13, and the first piezoelectric element 4 abuts against the outer wall of the first protrusion structure 13. The first protrusion structure 13 restricts the position of the first piezoelectric element 4 inside the first detection unit 1 through physical contact. On the one hand, it can align the electrode surface of the first piezoelectric element 4 that emits sound waves with the first detection surface 12, so that the emission path of the ultrasonic wave is determined. On the other hand, it can raise the first piezoelectric element 4 so that one electrode surface of the first piezoelectric element 4 can be attached to the surface of the first recessed structure 11, ensuring that the first wire can be connected to one electrode surface of the first piezoelectric element 4 after passing through the first recessed structure 11 or when it is inserted into the first recessed structure 11.

[0042] Please refer to Figures 4-5 The inner wall of the second detection unit 2 is provided with a second protrusion structure 23, and the second piezoelectric element 5 abuts against the outer wall of the second protrusion structure 23. The second protrusion structure 23 restricts the position of the second piezoelectric element 5 inside the second detection unit 2 through physical contact. On the one hand, it can align the electrode surface of the second piezoelectric element 5 that emits sound waves with the second detection surface 22, so that the ultrasonic wave receiving path is determined. On the other hand, it can raise the second piezoelectric element 5 so that one electrode surface of the second piezoelectric element 5 can be attached to the surface of the second recessed structure 21, ensuring that the second wire can be connected to one electrode surface of the second piezoelectric element 5 after passing through the second recessed structure 21 or when it is inserted into the second recessed structure 21.

[0043] Specifically, there are at least two first protrusion structures 13, which are symmetrically arranged, and the first piezoelectric element 4 is disposed between the two first protrusion structures 13. When the first piezoelectric element 4 deforms, the two first protrusion structures 13 can provide the first piezoelectric element 4 with pressure of the same magnitude but opposite direction, so as to avoid stress deformation or even breakage caused by uneven force on the first piezoelectric element 4.

[0044] The number of second protrusions 23 is at least two, and the two second protrusions 23 are arranged symmetrically. The second piezoelectric element 5 is disposed between the two second protrusions 23. When the second piezoelectric element 5 deforms, the two second protrusions 23 can provide the second piezoelectric element 5 with pressure of the same magnitude but opposite direction, so as to avoid stress deformation or even breakage caused by uneven force on the second piezoelectric element 5.

[0045] This ultrasonic sensor 100 has multiple sealing methods; please refer to the details. Figures 1-2The first sealing method involves the ultrasonic detection sensor 100 further including a sealant 8. The sealant 8 fills the interior of the first detection part 1, the second detection part 2, and the substrate 7, and encapsulates the circuit board 6, the first piezoelectric element 4, and the second piezoelectric element 5. Its function is twofold: First, the sealant 8 forms a watertight barrier, isolating moisture and corrosive ions. This prevents water vapor (especially conductive seawater) from penetrating the interior of the first detection part 1, the second detection part 2, and the substrate 7, creating conductive pathways between the two electrodes of the first piezoelectric element 4 and the two electrodes of the second piezoelectric element 5, thus preventing high-voltage breakdown or signal short circuits and complete failure of the ultrasonic detection sensor 100. It also prevents water corrosion of the electrodes of the first piezoelectric element 4 and the second piezoelectric element 5. Second, during the assembly of the substrate 7, the circuit board 6, the first piezoelectric element 4, and the second piezoelectric element 5, microscopic gaps are inevitable. If these gaps are filled with air, the extremely low acoustic impedance of air will cause near-complete reflection of sound waves at these air-filled locations, thus reducing the transmission efficiency of sound waves. Sealant 8, acting as an acoustic coupling agent, can flow and fill these microscopic gaps. The acoustic impedance of sealant 8 is far superior to that of air, ensuring more efficient transmission of sound wave energy and forming a complete acoustic pathway.

[0046] Please refer to the details. Figures 3-4 The second sealing method is that a mounting hole 71 is provided through the surface of the substrate 7, and a sealing element (not shown in the figure) is placed on the opening of the substrate 7. The substrate 7 is tightly connected to the sealing element through the mounting hole 71, so that the internal environment of the substrate 7 is isolated from the external environment.

[0047] The third sealing method involves filling the interior of the first detection part 1, the interior of the second detection part 2, and the interior of the base 7 with sealant 8, and connecting the base 7 and the sealing element through the mounting hole 71. Since this is simply a combination of the first and second sealing methods, it is not shown in the diagram.

[0048] The working principle of this utility model is described below to facilitate a better understanding of it:

[0049] For liquid transport structures such as water pipes, oil pipes, and syringes, the preliminary work involves placing the object to be tested in the detection space 3. At this time, the first detection unit 1 and the second detection unit 2 cooperate to clamp the object to be tested, and the first detection surface 12 of the first detection unit 1 is in contact with the object to be tested, and the second detection surface 22 of the second detection unit 2 is in contact with the object to be tested.

[0050] When a voltage is applied to the first piezoelectric element 4, it undergoes the inverse piezoelectric effect, vibrating at high frequency and generating ultrasonic waves. These ultrasonic waves sequentially pass through the first detection surface 12, the object under test, and the second detection surface 22, ultimately being received by the second piezoelectric element 5. During this process, when the liquid in the object under test is free of bubbles, the ultrasonic waves can penetrate smoothly because the acoustic impedance of the liquid is relatively close to that of the outer wall of the object. Although some ultrasonic energy is lost at each interface, the ultrasonic signal reaching the second piezoelectric element 5 still maintains a relatively high intensity. When the liquid in the object under test contains bubbles, the ultrasonic waves entering the bubbles from the outer wall of the object are equivalent to entering a low-impedance interface from a high-impedance interface. The ultrasonic waves are reflected due to the significant difference in acoustic impedance. Most of the ultrasonic energy is reflected back by this interface and cannot penetrate the bubbles and subsequent media; ultimately, only a small portion of the ultrasonic signal reaches the second piezoelectric element 5. When ultrasonic energy acts on the surface of the second piezoelectric element 5, the second piezoelectric element 5 deforms. This mechanical deformation generates a weak alternating voltage on the two electrodes of the second piezoelectric element 5, i.e., the second piezoelectric element 5 exhibits the positive piezoelectric effect. This alternating voltage signal generated by the second piezoelectric element 5 is transmitted via wires to a specific circuit (not shown in the figure) on the circuit board 6. This specific circuit continuously detects the intensity of this alternating voltage signal. When the signal intensity is higher than a predetermined threshold, it is determined that there are no air bubbles inside the liquid of the object being tested. When the signal intensity suddenly drops or falls below the predetermined threshold, this specific circuit determines that air bubbles have passed through, and then performs subsequent operations (such as outputting an alarm signal).

[0051] For liquids, the initial step is to install the ultrasonic sensor 100 in a specific liquid container, allowing the liquid inside the container to flow into the detection space 3.

[0052] When a voltage is applied to the first piezoelectric element 4, it undergoes the inverse piezoelectric effect, vibrating at high frequency and generating ultrasonic waves. These ultrasonic waves pass sequentially through the first detection surface 12, the object under test, and the second detection surface 22, ultimately being received by the second piezoelectric element 5. During this process, due to the significant difference in acoustic impedance between air and water, when the water level in the liquid container is lower than the area where the detection space 3 is located, the detection space 3 is filled with air. After the ultrasonic waves are emitted from the first piezoelectric element 4, they pass through the interface between the first detection surface 12 and the air. Due to the large difference in acoustic impedance, most of the ultrasonic energy is reflected, so the second piezoelectric element 5 can only receive a weak signal, allowing a specific circuit to determine that the space is filled with air (equivalent to a lack of water), i.e., the water level is below a certain value. When the water level in the liquid container is higher than the area where the detection space 3 is located, the detection space 3 is filled with liquid. After the ultrasonic waves are emitted from the first piezoelectric element 4, they pass through the liquid and reach the second piezoelectric element 5. During this process, the difference in acoustic impedance between the first detection surface 12, the liquid, and the second detection surface 22 is smaller. Therefore, most of the ultrasonic waves can reach the second piezoelectric element 5, so the second piezoelectric element 5 receives a high-intensity signal, thereby allowing a specific circuit to determine that the water level inside the liquid container is higher than a certain value.

[0053] Please refer to the details. Figures 6-7 , Figure 6 This is a three-dimensional structural diagram of the second embodiment of the present invention. Figure 7 This is a cross-sectional schematic diagram of the ultrasonic detection sensor 100. The difference between the second embodiment and the first embodiment is that the substrate 7 is removed, and the connection between the first detection unit 1 and the second detection unit 2 is changed, specifically:

[0054] In this embodiment, the two ends of the first detection unit 1 and the two ends of the second detection unit 2 are connected, and the interiors of the first detection unit 1 and the second detection unit 2 are connected. A circuit board 6 is disposed inside the first detection unit 1. One end of a first wire is connected to the circuit board 6, and the other end of the first wire passes through the first recessed structure 11 and connects to an electrode surface of the first piezoelectric element 4. One end of a second wire is connected to the circuit board 6, and the other end of the second wire passes through the second recessed structure 21 and connects to an electrode surface of the second piezoelectric element 5. In another embodiment, the circuit board 6 may also be disposed inside the second detection unit 2; this is not limited here.

[0055] Specifically, the first detection unit 1 and the second detection unit 2 are respectively arc-shaped. When the two ends of the first detection unit 1 and the two ends of the second detection unit 2 are connected, the detection space 3 formed by the first detection unit 1 and the second detection unit 2 is circular.

[0056] More specifically, the cross-sectional dimensions of the first detection unit 1 gradually increase from the middle to both ends, and the cross-sectional dimensions of the second detection unit 2 also gradually increase from the middle to both ends. The first detection surface 12 is located on the inner side of the middle portion of the first detection unit 1, and the second detection surface 22 is located on the inner side of the middle portion of the second detection unit 2. The advantages of this design are: 1. By reducing the amount of material used in the middle portion of the first detection unit 1 and the second detection unit 2 where strength requirements are not high, the ultrasonic detection sensor 100 becomes smaller and more portable, directly resulting in a lighter design. 2. Because the two ends of the first detection unit 1 and the two ends of the second detection unit 2 have sufficiently large cross-sectional dimensions, the connection between the two ends of the first detection unit 1 and the two ends of the second detection unit 2 has a larger connection area, making the connection between the first detection unit 1 and the second detection unit 2 more stable.

[0057] In this embodiment, the first detection unit 1 and the second detection unit 2 are integrally formed. In another embodiment, the two ends of the first detection unit 1 and the two ends of the second detection unit 2 are connected by snap-fit, which is not limited here.

[0058] Other technical features and effects are the same as in the first embodiment. Please refer to the following for details. Figures 1-5 Explanation.

Claims

1. An ultrasonic detection sensor, characterized by, include: A first detection unit and a second detection unit, wherein the inner wall of the first detection unit is provided with a first recessed structure and the inner wall of the second detection unit is provided with a second recessed structure, the first detection unit has a first detection surface and the second detection unit has a second detection surface, the first detection surface and the second detection surface are opposite to each other and spaced apart, and the first detection surface and the second detection surface together form a detection space. The first piezoelectric element is disposed inside the first detection unit, and the second piezoelectric element is disposed inside the second detection unit; It also includes a circuit board, one end of a first wire is connected to the circuit board, the other end of the first wire passes through the first recessed structure and is connected to an electrode surface of the first piezoelectric element, one end of a second wire is connected to the circuit board, the other end of the second wire passes through the second recessed structure and is connected to an electrode surface of the second piezoelectric element.

2. The ultrasonic detection sensor according to claim 1, characterized in that: It also includes a substrate, with the first detection part and the second detection part respectively disposed on a surface of the substrate, and the interior of the first detection part, the interior of the second detection part and the interior of the substrate are connected; The circuit board is disposed inside the substrate.

3. The ultrasonic detection sensor according to claim 2, characterized in that: The inner wall of the first detection unit is provided with a first protrusion structure, and the first piezoelectric element abuts against the outer wall of the first protrusion structure; The inner wall of the second detection part is provided with a second protrusion structure, and the second piezoelectric element abuts against the outer wall of the second protrusion structure.

4. The ultrasonic detection sensor according to claim 3, characterized in that: The number of the first protrusion structure is at least two, the two first protrusion structures are symmetrically arranged, and the first piezoelectric element is disposed between the two first protrusion structures; The number of the second protrusion structure is at least two, the two second protrusion structures are arranged symmetrically, and the second piezoelectric element is disposed between the two second protrusion structures.

5. The ultrasonic detection sensor according to claim 2, characterized in that: It also includes a sealant, which fills the interior of the first detection part, the interior of the second detection part, and the interior of the substrate, respectively, and the sealant encapsulates the circuit board, the first piezoelectric element, and the second piezoelectric element.

6. The ultrasonic detection sensor according to claim 2 or 5, characterized in that: The surface of the substrate is provided with a through mounting hole, a sealing element is provided over the opening of the substrate, and the substrate is connected to the sealing element through the mounting hole.

7. The ultrasonic detection sensor according to claim 1, characterized in that: The two ends of the first detection unit are connected to the two ends of the second detection unit, and the interior of the first detection unit is connected to the interior of the second detection unit. The circuit board is disposed inside the first detection unit or inside the second detection unit.

8. The ultrasonic detection sensor according to claim 7, characterized in that: The first detection section and the second detection section are respectively arc-shaped.

9. The ultrasonic detection sensor according to claim 8, characterized in that: The cross-sectional dimensions of the first detection unit gradually increase from the middle to both ends, and the cross-sectional dimensions of the second detection unit gradually increase from the middle to both ends; The first detection surface is located on the inner side of the middle part of the first detection section, and the second detection surface is located on the inner side of the middle part of the second detection section.

10. The ultrasonic detection sensor according to claim 1, characterized in that: On a plane parallel to the first detection surface, the projections of the first detection surface and the second detection surface completely or partially overlap.

11. The ultrasonic detection sensor according to claim 1, characterized in that: The first detection surface is a smooth plane, and the second detection surface is a smooth plane.

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