Ultrasonic sensor with novel sound transmission layer

Abstract

An ultrasonic sensor with a novel sound transmission layer of the utility model relates to the sensor technology field, and comprises a housing, a sound transmission layer arranged in the housing, and a ceramic sheet, the top of the sound transmission layer is provided with an upper surface, the ceramic sheet is arranged on the upper surface, the bottom of the sound transmission layer is provided with a lower surface, and the lower surface is provided with a lower surface. The area of the lower surface is smaller than the area of the upper surface, specifically, due to the fact that the area of the lower surface of the sound transmission layer is smaller than the area of the upper surface, when the ceramic chip emits sound waves, the sound waves are diffused on the upper surface firstly, and due to the fact that the area of the lower surface is small, the sound waves can be concentrated and form a more focused propagation mode when being transmitted to the lower surface. The sound waves converge from a large area to a small area, so that concentrated and directional diffusion is formed in the propagation process, the directivity of the sound waves becomes more obvious through the diffusion mode, and the sound waves can be transmitted to a specific area more accurately.

Description

TECHNICAL FIELD

[0001] The utility model relates to sensor technical field, especially a kind of ultrasonic sensor with novel sound-transmitting layer. BACKGROUND

[0002] Ultrasonic sensor is widely used in distance measurement, object detection, fluid monitoring and other fields, with non-contact, high sensitivity and other advantages, in practical application, the performance requirements of sensor not only include high sensitivity and low noise, but also often need to consider the directivity of sensor, to adapt to the space and directional restriction in installation and use process.

[0003] The directivity of sensor refers to the directionality of its sound wave propagation, usually represented by wave velocity angle, the smaller the wave velocity angle, the better the directivity of sensor, can more accurately detect specific area, for high-frequency air detection sensor, especially in the high frequency range of 100KHz to 500KHz, wave velocity angle usually requires as small as possible, to ensure that ultrasonic waves can be focused in a specific detection area, reduce the detection error caused by too large wave velocity angle.

[0004] The size of wave velocity angle is mainly determined by two factors: working frequency and radiation area. Specifically, in high-frequency sensor, the higher the working frequency, the smaller the wave velocity angle, high-frequency ultrasonic waves have shorter wavelength, so that the sound wave has strong directionality when propagating in air, for high-frequency air detection sensor with frequency in the range of 100KHz to 500KHz, the working frequency is already in a certain standard range, so the control of wave velocity angle mainly depends on the radiation area.

[0005] Radiation area is the physical area occupied by the emitting surface of ultrasonic sensor, the larger the radiation area, the wider the propagation of ultrasonic waves in space, and the wave velocity angle also increases, since in practical application, the radiation area is usually limited by installation space and physical size, therefore, the adjustment space of radiation area is limited, and it is difficult to further significantly reduce the wave velocity angle.

[0006] Traditional methods usually adjust working frequency or increase or decrease radiation area to optimize wave velocity angle, but for high-frequency air detection sensor for specific purposes, the working frequency has been basically determined, and the adjustment space of radiation area is relatively limited, therefore, how to further improve the directivity under these limited conditions has become an important direction of technical research.

[0007] The utility model is proposed to solve the technical problems in the prior art. UTILITY MODEL CONTENT

[0008] The utility model is proposed to solve the technical problems in the prior art.

[0009] The utility model discloses a technical scheme that solves its technical problem adopts:

[0010] An ultrasonic sensor with novel sound transmission layer, including casing, be located in the casing in the sound transmission layer and ceramic sheet, the top of sound transmission layer is equipped with upper surface, the ceramic sheet is located on the upper surface, the bottom of sound transmission layer is equipped with lower surface, and the area of lower surface is less than the upper surface area.

[0011] An ultrasonic sensor with novel sound transmission layer as described above, the ratio of the upper surface area and the lower surface area meets the following range: 0.60 ~0.96.

[0012] An ultrasonic sensor with novel sound transmission layer as described above, the thickness of sound transmission layer is H, and the diameter of upper surface is L, wherein H and L meet: 0.195≤H / L≤0.225.

[0013] An ultrasonic sensor with novel sound transmission layer as described above, the bottom of casing is equipped with avoiding hole, and the bottom of sound transmission layer is stretched out outside casing through avoiding hole.

[0014] An ultrasonic sensor with novel sound transmission layer as described above, the sound transmission layer includes stretch-out part and built-in part, the stretch-out part is the part of sound transmission layer that stretches out outside casing, the built-in part is the part of sound transmission layer that is built in casing, the thickness of stretch-out part is h, and the thickness of sound transmission layer is H, wherein h and H meet: 0.03≤h / H≤0.25.

[0015] An ultrasonic sensor with novel sound transmission layer as described above, the lower surface is plane or concave.

[0016] An ultrasonic sensor with novel sound transmission layer as described above, the connection of lower surface and sound transmission layer side wall is provided as circular arc.

[0017] An ultrasonic sensor with novel sound transmission layer as described above, the casing includes shell and inner shell, the inner shell is located in shell, and the sound transmission layer and ceramic sheet are located in inner shell.

[0018] The utility model discloses a technical scheme that solves its technical problem adopts:

[0019] The utility model relates to a sensor technical field, it includes casing, the casing in the sound -transmitting layer and ceramic sheet of sound -transmitting layer, the top of sound -transmitting layer is equipped with upper surface, the ceramic sheet is equipped with upper surface, the bottom of sound -transmitting layer is equipped with lower surface, the area of lower surface is less than upper surface area, specifically, because the area of lower surface of sound -transmitting layer is less than upper surface area, when ceramic sheet sends out sound wave, sound wave first diffuses on upper surface, because the area of lower surface is small, when sound wave is passed to lower surface, will concentrate and form more focused propagation mode, in a word, sound wave converges from a larger area to a smaller area, thereby forms concentration, directional diffusion in the propagation process, this diffusion mode makes the directivity of sound wave become more obvious, can more accurately transmit to specific area.

[0020] The utility model will be further described below in combination with the drawings and specific embodiment. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is one of cross section schematic drawing of the utility model (lower surface is plane shape);

[0022] Figure 2 It is second cross section schematic drawing of the utility model (lower surface is plane shape);

[0023] Figure 3 It is the overhead view schematic diagram of the sound -transmitting layer of the utility model (lower surface is plane shape);

[0024] Figure 4 It is the cross section schematic diagram of the sound -transmitting layer of the utility model (lower surface is plane shape);

[0025] Figure 5 It is one of cross section schematic drawing of another embodiment of the utility model (lower surface is concave shape);

[0026] Figure 6 It is second cross section schematic drawing of another embodiment of the utility model (lower surface is concave shape). DETAILED DESCRIPTION

[0027] The embodiment of the utility model is explained in detail below in combination with the drawings.

[0028] As Figures 1 to 6 Shown, a kind of ultrasonic sensor with novel sound -transmitting layer of the utility model of this embodiment, including casing 1, sound -transmitting layer 2 being equipped in casing 1 and ceramic sheet 3, the top of sound -transmitting layer 2 is equipped with upper surface 21, the ceramic sheet 3 is equipped with upper surface 21, the bottom of sound -transmitting layer 2 is equipped with lower surface 22, the area of lower surface 22 is less than upper surface 21 area.

[0029] Specifically, since the area of ​​the lower surface 22 of the sound-transmitting layer 2 is smaller than that of the upper surface 21, when the ceramic sheet 3 emits sound waves, the sound waves first diffuse on the upper surface 21. Because the area of ​​the lower surface 22 is smaller, the sound waves will concentrate and form a more focused propagation pattern when they are transmitted to the lower surface. In short, the sound waves converge from a larger area to a smaller area, thus forming a concentrated and directional diffusion during propagation. This diffusion method makes the directionality of the sound waves more obvious and can be transmitted to a specific area more accurately.

[0030] In traditional designs, sound waves spread evenly in all directions, forming a large wave velocity angle, which results in weak sensor directivity. However, with this design, as the sound waves pass through the gradually decreasing area of ​​the sound-transmitting layer, the propagation path gradually becomes concentrated, reducing the diffusion of sound waves to non-target areas and thus effectively improving the directivity of the sound waves.

[0031] By making the area of ​​the lower surface 22 smaller than that of the upper surface 21, the propagation path of the sound wave is gradually contracted and focused, significantly reducing the wave velocity angle. This means that the sensor's detection range will be more concentrated, enabling more accurate detection of specific areas and avoiding unnecessary false detections or noise effects.

[0032] Furthermore, by designing the geometry of the sound-transmitting layer, the directivity can be optimized through reasonable sound wave guidance without changing the sensor size and frequency, providing a solution to the bottleneck that traditional design methods cannot overcome.

[0033] Traditional methods typically require adjusting the directivity by changing the operating frequency or increasing or decreasing the radiating area, which may affect other sensor performance characteristics (such as sensitivity and frequency response). This solution, through improvements to the geometry of the acoustic layer, can optimize directivity without significantly altering the sensor size or operating frequency. This allows the sensor to improve its performance based on the original design, while avoiding compromises in frequency and size.

[0034] like Figures 1 to 6 As shown, in this embodiment, the ratio of the area of ​​the upper surface 21 to the area of ​​the lower surface 22 satisfies the following range: 0.60 ~ 0.96.

[0035] Specifically, the upper surface 21 has a larger area, while the lower surface 22 has a smaller area, with an area ratio ranging from 0.60 to 0.96. This means that the area difference between the upper and lower surfaces of the sound-transmitting layer 2 is limited, neither very small nor too large.

[0036] When the ultrasonic waves are emitted by the ceramic sheet and pass through the sound-transmitting layer, the sound waves are first diffused on the upper surface 21, and as the sound waves are transmitted to the lower surface 22, due to the smaller area of the lower surface 22, the sound waves will produce a more concentrated propagation mode when converging to the lower surface. The area difference causes the propagation path of the sound waves to gradually focus, avoiding unnecessary diffusion.

[0037] The regulation of the area ratio determines the convergence degree of the sound waves in the diffusion process. A larger upper surface provides a wider propagation area, which can effectively disperse the energy of the sound waves, while a smaller lower surface plays a "converging" role, making the propagation range of the sound waves more concentrated.

[0038] By appropriately designing the area ratio (the ratio of the area of the upper surface 21 to the area of the lower surface 22), the sound wave concentration is controlled while avoiding excessive area difference that leads to excessive change in wave speed angle, thereby maintaining moderate directivity optimization.

[0039] When the sound waves pass through the large-area upper surface, the energy is relatively widely distributed. As the sound waves gradually contact the smaller lower surface, the energy is concentrated in a smaller area. This design achieves a lower wave speed angle through the focusing effect of the sound waves, making the sound waves of the sensor more accurately directed to the target area, reducing the scattering of the beam.

[0040] Through reasonable area ratio design (ratio range of 0.60 ~0.96), the directionality of the sound wave propagation is effectively optimized. Compared with traditional design, through the optimization of this structure, the sound waves are more concentrated and have stronger directivity, thereby improving the detection ability of the sensor for target objects and reducing errors and interference in measurement.

[0041] The optimized directivity allows the sensor to more accurately locate and detect the target, especially in high-precision application scenarios. This design can effectively improve the measurement accuracy of the ultrasonic sensor.

[0042] As shown in Figures 1 to 6 The thickness of the sound-transmitting layer 2 is H, and the diameter of the upper surface 21 is L, where H and L satisfy: 0.195≤H / L≤0.225, and the ratio of the area of the upper surface 21 to the area of the lower surface 22 satisfies the following range: 0.60 ~0.96, and the directivity angle of the ultrasonic sensor is significantly improved.

[0043] Specifically, the ratio (H / L) between the thickness H of the sound-transparent layer and the diameter L of the upper surface 21 directly affects the propagation path and energy distribution of the ultrasonic waves within the sound-transparent layer. When the H / L ratio is between 0.195 and 0.225, the propagation effect of the ultrasonic waves can be within a relatively concentrated range, which means that the ultrasonic waves will not be excessively scattered when passing through the sound-transparent layer, nor will they produce excessive diffraction due to overly concentrated design, thereby avoiding the situation of excessively large or small beam spreading.

[0044] The optimized design of this ratio ensures that the sound-transparent layer is neither too thin to cause excessive energy loss nor too thick to cause excessive diffraction and propagation loss. Therefore, by controlling the H / L ratio, the propagation path of the ultrasonic waves becomes more stable and orderly, and the beam is more concentrated.

[0045] By designing the area ratio of the upper surface 21 and the lower surface 22 to be between 0.60 and 0.96, the propagation path of the ultrasonic waves is further optimized. The larger upper surface allows the sound waves to spread out in the initial stage, and the smaller lower surface serves to focus the sound waves into a smaller area.

[0046] This area ratio design ensures that the sound waves can be concentrated and reduce diffusion in other directions, thereby improving directivity, enabling the ultrasonic sensor to more accurately point to the target area, reducing false detection and background noise interference.

[0047] The adjustment of the thickness and area ratio of the sound-transparent layer works together to optimize the propagation path of the ultrasonic waves, ensuring that the sound waves can have sufficient diffusion range in the initial stage while being focused and concentrated at the lower surface of the sound-transparent layer. This structure effectively enhances the directivity of the ultrasonic waves, reduces beam scattering, and ensures that the directional accuracy of the ultrasonic sensor is more precise, enabling more concentrated detection of specific targets.

[0048] The most significant benefit is the improvement in directivity. By adjusting the ratio (H / L) of the thickness of the sound-transparent layer to the diameter of the upper surface and the area ratio, the ultrasonic propagation path of the sensor is more concentrated, and the sound wave propagation range is more accurate, which effectively reduces beam spreading, enabling the ultrasonic waves to more accurately point to the target area, improving the performance of the sensor in spatial positioning, detection, etc.

[0049] Better directivity directly improves measurement accuracy, as the sound waves are no longer excessively scattered, and the sensor can accurately capture the target signal, reducing the influence of external environmental interference on the measurement results, which is of great significance for accurately measuring target distance, shape, position, etc., especially in high-precision applications such as autonomous driving and industrial detection.

[0050] The optimized directivity means that the energy of the ultrasonic waves is more concentrated and no longer diffuses disorderly in all directions. This not only improves the signal strength of the sensor, but also greatly reduces the interference of environmental noise and other irrelevant targets, improves the anti-interference ability of the sensor in complex environments, and ensures the stability of the measurement results.

[0051] The optimization of the sound-transmitting layer structure enables the ultrasonic sensor to maintain high directivity and precision in complex environments, especially in situations where space is limited or signals are easily disturbed, which makes the sensor perform more outstandingly in applications such as unmanned driving, robot navigation, industrial automation, etc. that require high directivity and high stability.

[0052] By precisely controlling the ratio of H / L and the ratio of the area of the upper surface 21 to the area of the lower surface 22, the energy transmission efficiency of the ultrasonic waves is improved, the propagation of the sound waves is more concentrated, and the energy loss is reduced. Especially in high-frequency applications, such a design helps to ensure the efficiency of signal transmission, thereby improving the sensitivity and response speed of the sensor.

[0053] Further, if the ratio of the thickness of the sound-transmitting layer (H) to the diameter of the upper surface (L) is less than 0.195 or greater than 0.225, or the ratio of the areas of the upper surface and the lower surface is less than 0.60 or greater than 0.96, it will have a negative impact on the performance of the ultrasonic sensor, mainly in the following aspects:

[0054] 1. The impact of the ratio of the thickness of the sound-transmitting layer to the diameter (H / L) being out of range, such as H / L < 0.195:

[0055] If the sound-transmitting layer is too thin (H is too small relative to L), the ultrasonic waves will diffuse widely on a shorter propagation path, resulting in poor directivity of the ultrasonic waves, which means that the energy of the sound waves will be quickly dispersed and difficult to concentrate on the target, increasing the measurement error and reducing the detection accuracy of the sensor.

[0056] And due to the insufficient thickness of the sound-transmitting layer, the attenuation of the sound waves may be more serious, resulting in a large signal loss, a decrease in detection distance and sensitivity, especially in high-frequency sensors.

[0057] If H / L > 0.225, i.e. the thickness of the sound-transmitting layer is too large, the ultrasonic waves are prone to excessive diffraction when transmitting through the sound-transmitting layer, which will cause the sound waves to disperse to a wider area, reducing the focusing of the sound waves and affecting the directivity.

[0058] And increasing the thickness of the sound-transmitting layer will cause an increase in energy loss during the propagation of the sound waves, thereby reducing the intensity of the sound waves and the detection efficiency of the sensor.

[0059] 2. The impact of area ratios exceeding the range, such as the ratio of the area of ​​the upper surface 21 to the area of ​​the lower surface 22 being less than 0.60:

[0060] If the area of ​​the upper surface is too large relative to the lower surface, the sound waves will spread too much on the upper surface and will be difficult to effectively converge to the lower surface. This will cause the energy distribution of the sound waves to be too dispersed during propagation, reduce the directivity, and decrease the positioning accuracy and detection capability of the ultrasonic sensor.

[0061] Furthermore, the propagation path of sound waves cannot be effectively focused in a specific direction, and the beam width is relatively large, causing ambiguity in the detection area, making it difficult for the sensor to accurately locate the target.

[0062] If the ratio of the area of ​​the upper surface 21 to the area of ​​the lower surface 22 is greater than 0.96, and the area of ​​the upper surface is too small relative to the lower surface, the sound waves will quickly concentrate on the lower surface, which may result in an overly narrow beam. Although the directivity is enhanced, this over-focusing will make the sensor's detection range too limited and make it easy to miss the target.

[0063] Excessive area differences may cause an imbalance in the propagation speed and angle of sound waves, resulting in waveform distortion or nonlinear effects, which can affect the stability and measurement accuracy of the sensor.

[0064] When the ratio of the thickness to the diameter of the acoustic layer (H / L) or the ratio of the area of ​​the upper and lower surfaces deviates from the optimal range, the beam control capability of the ultrasonic sensor will be limited, which may lead to excessive scattering or excessive focusing, thereby affecting the detection accuracy and directionality of the sensor.

[0065] The measurement accuracy of ultrasonic sensors is highly dependent on the concentration of the beam. Poor directivity can lead to blurred boundaries of the detection area, or even misjudgment or missed detection. This defect can cause even greater measurement errors, especially in complex environments.

[0066] Non-ideal sound wave propagation patterns can easily cause noise interference from the surrounding environment, reducing the sensor's anti-interference ability in complex or dynamic environments. It may also cause excessive response to background noise, affecting the clarity of the signal.

[0067] like Figures 1 to 6 As shown, the bottom of the housing 1 in this embodiment is provided with a clearance hole 11. The bottom of the sound-transparent layer 2 extends out of the housing 1 through the clearance hole 11, which means that the sound wave emission source is not completely surrounded by the housing. The sound-transparent layer 2 can propagate sound waves more freely. This design eliminates the restriction of the housing on the sound waves, reduces the reflection, scattering or attenuation of the sound waves, and can maintain the directionality of the sound wave propagation. The part of the sound-transparent layer that extends out of the housing is directly exposed to the external environment. Ultrasonic waves can be emitted more directly to the target area without being interfered with or blocked by the edge of the housing, thereby improving the directionality of the sound waves.

[0068] Further, the design of the avoidance hole 11 essentially provides a "channel" for the ultrasonic waves to propagate out without being affected by the bottom of the shell. The presence of the avoidance hole prevents the diffraction effect or beam scattering that may occur when the ultrasonic waves pass through the edge of the shell.

[0069] Through the avoidance hole 11, the bottom of the sound-transparent layer extends out of the shell, which helps to reduce the path loss of the sound waves when passing through the shell and avoids unnecessary noise or signal errors caused by reflection or scattering at the edge of the bottom of the shell.

[0070] Since the bottom of the sound-transparent layer is directly exposed to the external environment, the sound waves can be more concentratedly emitted, thereby improving the directivity of the ultrasonic sensor. This design can effectively control the propagation path of the sound waves, reduce the diffusion of the sound waves in unnecessary directions, reduce the influence of the shell on the sound waves, and enable the sound waves to be more accurately focused in a specific direction or area after emission, thereby improving the positioning accuracy and detection capability of the ultrasonic sensor.

[0071] Through this design, the directivity is further optimized. After the bottom of the sound-transparent layer extends out of the shell, the sound wave emission is more concentrated, reducing scattering caused by shell interference. Through the design of the avoidance hole, the sound waves can be more accurately directed to the target area, avoiding beam diffusion caused by shell edge reflection or interference.

[0072] As shown in Figures 1 to 6 The sound-transparent layer 2 of the present embodiment includes an extension part 23 and an embedded part 24. The extension part 23 is the part of the sound-transparent layer 2 that extends out of the shell 1, and the embedded part 24 is the part of the sound-transparent layer 2 that is embedded in the shell 1. The thickness of the extension part 23 is h, and the thickness of the sound-transparent layer 2 is H, where h and H satisfy: 0.03≤h / H≤0.25, i.e., the thickness of the extension part 23 cannot exceed 75% of the thickness of the sound-transparent layer 2, otherwise the sensitivity of the sound-transparent layer will be affected, and the thickness of the extension part 23 cannot be less than 97% of the thickness of the sound-transparent layer 2, otherwise it will not improve the directivity.

[0073] Specifically, the extension part 23 extends out of the shell from the outside, which can be directly exposed to the external environment, so that the ultrasonic waves can be more freely emitted, avoiding the edge of the shell interfering with the propagation of the ultrasonic waves, and enhancing the directivity of the sound waves. The embedded part 24 is still retained inside the shell and is closely connected with the structure of the shell, providing sufficient strength and stability to maintain the shape and function of the entire sound-transparent layer.

[0074] The total thickness H of the acoustic layer includes the thickness of the protrusion 23 and the built-in portion 24. The ratio of the thickness h of the protrusion 23 to the total thickness H of the acoustic layer is limited to 0.03 ≤ h / H ≤ 0.25. This ratio control ensures that the thickness of the protrusion is neither too large nor too small, thereby achieving optimal directivity optimization and sensitivity maintenance.

[0075] When h / H is too large (exceeding 0.25): Excessive thickness of the protrusion will lead to a decrease in the overall sensitivity of the acoustic layer 2. Excessive thickness of the protrusion may hinder the effective propagation and concentration of ultrasonic waves, thereby reducing the detection accuracy of the sensor. In addition, the energy of ultrasonic waves will be attenuated too much in the excessively thick protrusion, resulting in a shortened detection distance and a slower response speed.

[0076] When h / H is too small (below 0.03): If the protrusion is too thin, it cannot fully play its role in improving directivity. Although the built-in part can maintain the stability and structural strength of the sensor, the ultrasonic wave emission will be greatly affected by the shell, resulting in greater beam diffusion of the ultrasonic wave and poorer directivity. As a result, it cannot be effectively concentrated in the target area, and the accuracy decreases.

[0077] Furthermore, the thickness control of the protrusion and the internal part ensures that the acoustic layer can maintain the sensor sensitivity while having sufficient directivity optimization. By adjusting the thickness h of the protrusion, the acoustic layer can emit sound waves more concentratedly without affecting the overall performance, thereby enhancing the directionality of the ultrasonic waves and enabling it to detect targets more accurately.

[0078] The protrusion design allows the bottom of the acoustic layer to be unaffected by the bottom of the housing, allowing ultrasound waves to propagate more freely outward. By precisely controlling the thickness (h) of the protrusion, the emission path of the sound waves can be optimized, reducing their diffusion and making the beam more concentrated in the target area, thereby improving the directivity of the ultrasonic sensor.

[0079] The thickness h of the protrusion cannot exceed 25% of the total thickness H of the acoustic layer (h / H ≤ 0.25). This ensures that the energy of the ultrasonic wave does not attenuate too much in the acoustic layer, avoiding the decrease in sensitivity caused by the excessive thickness of the protrusion. The built-in part 24 of the acoustic layer still plays a role in maintaining the overall stability and sensitivity of the sensor.

[0080] like Figures 1 to 6 As shown, the lower surface 22 in this embodiment is either flat or concave. Preferably, in some embodiments, the lower surface 22 is flat. In this case, when ultrasonic waves are emitted from the bottom of the acoustic layer, the propagation direction of the sound waves is not significantly affected by the curvature of the surface, and the sound waves propagate along a straight line, maintaining a relatively uniform beam shape. The planar design can reduce the scattering of ultrasonic waves, thus maintaining the directionality and directional properties of the sound waves.

[0081] The planar shape helps the uniform propagation of sound waves, avoiding unnecessary beam deflection or diffusion, especially in applications where excessive focusing is not required, the planar design provides a more concise and straight sound wave propagation path.

[0082] In other embodiments, the lower surface 22 is concave, then through the design of curved surface shape, can make the emission of ultrasonic waves affected by focusing effect, concave design has the function of reflection and focusing, can focus the sound waves emitted from the sound transmission layer to a certain specific area or direction, thereby enhancing the concentration and directivity of the beam.

[0083] In this design, the emission of ultrasonic waves will first propagate along the curved surface, and then focus to the predetermined direction, which can ensure that the sound waves are highly concentrated in a specific area, improving the detection accuracy of the sensor.

[0084] The lower surface 22 can also adopt other shapes of surfaces, which can be selected according to actual needs.

[0085] As shown in Figures 1 to 6 The lower surface 22 of the present embodiment is provided with a circular arc shape at the connection with the side wall of the sound transmission layer 2, and the sound transmission layer is in a cylindrical shape.

[0086] Preferably, the circular arc connection is smooth transition, which eliminates the interference of sharp corners and ensures that the ultrasonic waves can propagate in a smoother path. The shape of the circular arc can effectively reduce the reflection loss of sound waves at the connection site, avoiding unnecessary scattering or deflection of ultrasonic waves during emission and reception. In this way, the propagation of sound waves is more concentrated, and the beam is more stable, improving the directivity of the sensor.

[0087] Preferably, the smooth transition of the circular arc connection helps the ultrasonic waves to transition more smoothly from the sound transmission layer 2 to the lower surface 22, reducing energy loss and unnecessary reflection. This design makes the propagation path of the ultrasonic waves more linear and focused, improving the emission effect of the sound waves.

[0088] By introducing the circular arc shape, the transition at the connection site becomes softer, so that the ultrasonic waves are not easily affected by the sudden change during emission, avoiding the scattering effect that may be caused by traditional sharp corner design.

[0089] The circular arc connection ensures that the sound waves do not produce abrupt angle changes when contacting the side wall of the sound transmission layer 2, avoiding beam scattering and energy loss caused by irregular surfaces. Therefore, the sound waves can propagate more concentratedly and directionally, thereby improving the measurement accuracy and detection range of the sensor.

[0090] The circular arc shape can disperse stress, avoids stress concentration phenomenon that can be generated at sharp corners, and thus improves durability and stability of the structure, and the design enhances mechanical strength of the ultrasonic sensor, and the ultrasonic sensor can maintain long-term stable performance in a high-strength working environment.

[0091] As shown in Figures 1 to 6 The shell 1 of the embodiment includes an outer shell 12 and an inner shell 13, the inner shell 13 is arranged in the outer shell 12, and the sound-transparent layer 2 and the ceramic sheet 3 are arranged in the inner shell 13.

[0092] Preferably, the outer shell 12 serves as an external protective layer of the sensor, mainly plays a protection role, resists physical impact, temperature change, chemical corrosion and the like of an external environment, and is usually made of a hard material (such as metal, plastic or the like) to ensure long-term stability of the sensor in a harsh environment.

[0093] The inner shell 13 is located inside the outer shell 12 and is responsible for providing mechanical support and structural protection for the internal electronic elements, the sound-transparent layer 2 and the ceramic sheet 3, and is generally made of a relatively flexible or vibration-isolating material to play a role in absorbing vibration and reducing impact, which helps to improve the anti-interference ability and anti-vibration ability of the sensor.

[0094] The inner shell 13 not only provides physical support, but also effectively isolates the working environment of the sound-transparent layer 2 and the ceramic sheet 3, avoids direct influence of external temperature change, humidity or mechanical vibration on the working precision of the sensor, the sound insulation and elasticity of the inner shell material help to reduce noise interference of the external environment, improve the signal-to-noise ratio of the ultrasonic sensor, and at the same time, the design of the inner shell 13 can effectively protect the internal sound-transparent layer 2 and the ceramic sheet 3 from direct damage in a bad environment.

[0095] Preferably, the outer shell 12 and the inner shell 13 are in a detachable or one-piece structure, and a suitable design can be selected according to actual needs.

[0096] In other embodiments, the shell 1 is in a whole shell structure, and a suitable design can be selected according to actual needs.

[0097] The above only further illustrates the technical content of the utility model by means of embodiments, so as to make it easier for the reader to understand, but does not represent that the embodiments of the utility model are limited to this, and any technical extension or re-creation made according to the utility model is also protected by the utility model. The protection scope of the utility model is subject to the claims.

Claims

1. An ultrasonic sensor having a novel acoustically transparent layer, characterized by, The application relates to a shell (1), a sound-permeable layer (2) arranged in the shell (1) and a ceramic sheet (3), wherein the top of the sound-permeable layer (2) is provided with an upper surface (21), the ceramic sheet (3) is arranged on the upper surface (21), the bottom of the sound-permeable layer (2) is provided with a lower surface (22), and the area of the lower surface (22) is smaller than that of the upper surface (21).

2. The ultrasonic sensor with a novel acoustic transparent layer according to claim 1, characterized in that, The ratio of the area of the upper surface (21) to that of the lower surface (22) satisfies the range of 0.60-0.

96.

3. The ultrasonic sensor with a novel acoustic transparent layer according to claim 2, characterized in that, The thickness of the sound-permeable layer (2) is H, and the diameter of the upper surface (21) is L, wherein H and L satisfy the range of 0.195<=H / L<=0.

225.

4. The ultrasonic sensor with a novel acoustic transparent layer according to any one of claims 1 to 3, characterized in that, The bottom of the shell (1) is provided with a clearance hole (11), and the bottom of the sound-permeable layer (2) extends out of the shell (1) through the clearance hole (11).

5. The ultrasonic sensor with a novel acoustically transparent layer according to claim 4, characterized in that, The sound-permeable layer (2) comprises an extending part (23) and an embedded part (24), the extending part (23) is the part of the sound-permeable layer (2) extending out of the shell (1), the embedded part (24) is the part of the sound-permeable layer (2) embedded in the shell (1), the thickness of the extending part (23) is h, and the thickness of the sound-permeable layer (2) is H, wherein h and H satisfy the range of 0.03<=h / H<=0.

25.

6. The ultrasonic sensor with a novel acoustic transparent layer according to any one of claims 1 to 3, characterized in that, The lower surface (22) is a plane or a concave surface.

7. The ultrasonic sensor with a novel acoustic transparent layer according to any one of claims 1 to 3, characterized in that, The connection between the lower surface (22) and the side wall of the sound-permeable layer (2) is in the shape of a circular arc.

8. The ultrasonic sensor with a novel acoustic transparent layer according to claim 1, wherein, The shell (1) comprises an outer shell (12) and an inner shell (13), the inner shell (13) is arranged in the outer shell (12), and the sound-permeable layer (2) and the ceramic sheet (3) are both arranged in the inner shell (13).

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