Ultrasonic sensor

Abstract

The invention relates to an ultrasonic sensor. The ultrasonic sensor comprises a first planar electrode and a second planar electrode which are oppositely arranged, the first planar electrode and the second planar electrode are at least partially attached and are insulated from each other to form a stable planar capacitor; wherein the first planar electrode comprises an insulating film and a first conductive layer which is arranged on one side, facing the second planar electrode, of the insulating film; the second planar electrode comprises a conductive substrate; an insulating layer is arranged between the first conductive layer and the conductive substrate. According to the ultrasonic sensor, the first planar electrode and the second planar electrode are used for replacing a piezoelectric ceramic piece to form a planar capacitor, and the technical defects caused by the piezoelectric ceramic piece production technology are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to an ultrasonic sensor. Background Art

[0002] Ultrasonic sensor is a sensor that uses sound wave medium to perform non-contact and wear-free detection of the object being detected.

[0003] The ultrasonic sensor in the related technology mainly includes a metal shell and a piezoelectric ceramic sheet installed in the metal shell. The piezoelectric ceramic sheet can both emit and receive ultrasonic waves. However, the current production technology of piezoelectric ceramic sheets has defects such as many and complex process steps, low yield, and poor consistency of the center frequency of piezoelectric ceramics, which leads to problems such as low production capacity, high cost, and serious material waste. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an improved ultrasonic sensor.

[0005] The technical solution adopted by the present invention to solve the technical problem is: construct an ultrasonic sensor, including a first planar electrode and a second planar electrode arranged opposite to each other; the first planar electrode and the second planar electrode are at least partially attached to each other and insulated from each other to form a stable planar capacitor;

[0006] Wherein, the first planar electrode comprises an insulating film, and a first conductive layer arranged on a side of the insulating film facing the second planar electrode; the second planar electrode comprises a conductive substrate;

[0007] An insulating layer is further provided between the first conductive layer and the conductive substrate.

[0008] In some embodiments, the insulating film is a plastic film, and the thickness of the insulating film ranges from 1 μm to 50 μm;

[0009] The first conductive layer is a metal layer, and the thickness of the first conductive layer is in the range of 1 nm-20 μm.

[0010] In some embodiments, the conductive substrate is a PCB circuit board, and the PCB circuit board is provided with a second conductive layer located on a side facing the first planar electrode;

[0011] Alternatively, the conductive substrate is a metal plate, and the thickness of the metal plate is in the range of 0.001 mm to 20 mm.

[0012] In some embodiments, the insulating layer is disposed on a side of the conductive substrate facing the first planar electrode, and a surface of the insulating layer facing the first planar electrode is arranged in a concave-convex manner;

[0013] Alternatively, the insulating layer is arranged on a side of the first conductive layer facing away from the insulating film, and the surface of the insulating layer facing the second planar electrode is arranged in a concave-convex manner.

[0014] In some embodiments, the ultrasonic sensor includes a housing, the housing having a supporting portion located therein and a communication port communicating with the outside;

[0015] The first planar electrode is placed on the supporting portion and is arranged opposite to the connecting port; wherein the insulating film isolates the first conductive layer from the outside.

[0016] In some embodiments, the ultrasonic sensor includes a connecting electrode located on a side of the first planar electrode facing away from the supporting portion, the connecting electrode being attached to the first conductive layer and electrically connected to the first conductive layer;

[0017] The ultrasonic sensor also includes a pressure ring arranged in the shell, the pressure ring abuts against a side surface of the connecting electrode facing away from the first planar electrode; and a snap-fit ​​structure is provided between the pressure ring and the shell to press the connecting electrode and the first planar electrode onto the supporting portion.

[0018] In some embodiments, the buckle structure includes a plurality of elastic channels circumferentially arranged on the pressure ring, and a plurality of first clamping blocks disposed on the inner circumference of the shell and corresponding to the plurality of elastic channels one by one;

[0019] The side wall of any of the elastic channels has elastic deformation capability, and the width of the opening of the elastic channel away from the connecting electrode is smaller than the length of the first card block;

[0020] The pressure ring passes over the first clamping block by utilizing the elasticity of the side wall of the elastic channel and is assembled between the first clamping block and the connecting electrode; wherein the channel end wall formed around the opening abuts against the first clamping block.

[0021] In some embodiments, the pressure ring is further provided with a accommodating area located on the side of the elastic channel away from the connecting electrode. The first clamping block passing through the elastic channel is located in the accommodating area and can abut against the side wall of the accommodating area to limit the circumferential displacement of the pressure ring.

[0022] In some embodiments, the pressure ring includes a ring body, and a plurality of groups of buckle assemblies arranged circumferentially and spaced apart on the periphery of the ring body; any group of buckle assemblies includes two buckle members arranged circumferentially and spaced apart along the ring body, and the elastic channel and the accommodating area are formed between the two buckle members;

[0023] Wherein, the deformation state of the elastic channel is that the two buckling parts are respectively inclined in directions away from each other; or, the side walls of the two buckling parts facing each other are elastic walls.

[0024] In some embodiments, the pressure ring is provided with a plurality of injection positions for injecting glue, so that the glue can be solidified and formed in one or more gaps formed by at least two combinations of the shell, the pressure ring, the connecting electrode and the first planar electrode; each of the injection positions is correspondingly formed on the peripheral side of each of the fasteners.

[0025] In some embodiments, the ultrasonic sensor includes a compression spring assembly, which is relatively fixed to a side of the second planar electrode facing away from the first planar electrode and abuts against the second planar electrode to apply a force to the second planar electrode to make it close to the first planar electrode.

[0026] In some embodiments, the compression spring assembly includes a main body and a first elastic portion between two ends of the main body, the first elastic portion has elastic deformation capability, and when the main body is fixed to one side of the second planar electrode, the first elastic portion is in a compressed state to achieve compression.

[0027] In some embodiments, the first elastic part is a tower spring, one end of the tower spring is connected to the main body, and the other end of the tower spring abuts against the second planar electrode;

[0028] Alternatively, the first elastic portion is a longitudinally long arc-shaped spring piece, and the arc-shaped spring piece protrudes from one side of the main body.

[0029] In some embodiments, a first clamping structure and a second clamping structure are respectively provided between the two opposite sides of the main body and the pressure ring to fix the compression spring assembly on the pressure ring.

[0030] In some embodiments, the first clamping structure includes a first fixing portion provided on one side of the main body, and a first mounting groove provided on the pressure ring; the first fixing portion includes two buckle segments, the two buckle segments extend outward along one side of the main body, and are spaced apart from each other; the two buckle segments have elastic deformation capability, and in a deformed state, they move closer to each other to enter the first mounting groove, and are clamped in the first mounting groove in a natural state;

[0031] And / or, the second clamping structure includes a second fixing portion arranged on the other side of the main body, and a second mounting groove arranged on the pressure ring; the second fixing portion is inserted into the second mounting groove.

[0032] In some embodiments, a locking structure is further provided between each of the buckle segments and the slot wall of the first mounting slot to limit the buckle segment from escaping from the first mounting slot.

[0033] In some embodiments, any of the locking structures includes a slot disposed at the top of the buckle segment, and a protrusion disposed on the wall of the first mounting groove; the slot is buckled onto the protrusion after the buckle segment enters the first mounting groove.

[0034] In some embodiments, the compression spring assembly further includes two second elastic parts respectively located on both sides of the trunk in the width direction;

[0035] The second elastic portion has elastic deformation capability, and when the trunk portion is fixed to the second planar electrode, the second elastic portion is in a deformed state to achieve compression.

[0036] In some embodiments, each of the second elastic parts includes a contact part for abutting against the electrode sheet, and a connecting part connecting the contact part with the main body;

[0037] There is a distance between the contact portion and the plane where the main body is located. After the contact portion is abutted, one end of the connecting portion connected to the contact portion is relatively displaced toward the plane where the main body is located to generate elastic force.

[0038] In some embodiments, the ultrasonic sensor further comprises a mesh cover detachably mounted on an end of the housing close to the first planar electrode;

[0039] A fixing structure is provided between the mesh cover and the shell to fix the mesh cover on the shell.

[0040] The implementation of the present invention has the following beneficial effects: the ultrasonic sensor replaces the piezoelectric ceramic sheet with the first planar electrode and the second planar electrode to form a planar capacitor, thereby avoiding the technical defects caused by the production technology of the piezoelectric ceramic sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0042] Figure 1 is a longitudinal cross-sectional view of the ultrasonic sensor of the present invention in Example 1;

[0043] Figure 2 is a schematic diagram of the structure of the second planar electrode of the ultrasonic sensor in some embodiments of the present invention in a top view;

[0044] Figure 3 is an exploded view of the ultrasonic sensor of the present invention in Example 2;

[0045] Figure 4 is a longitudinal cross-sectional view of the ultrasonic sensor of the present invention in Example 2;

[0046] Figure 5 is a schematic diagram of the structure of the housing in some embodiments of the present invention;

[0047] Figure 6 is a schematic diagram of a structure in which a first planar electrode is mounted on a housing in some embodiments of the present invention;

[0048] Figure 7 is a schematic diagram of a structure in which a connecting electrode of an ultrasonic sensor is mounted on a first planar electrode in some embodiments of the present invention;

[0049] Figure 8 It is a schematic diagram of the structure in which the pressure ring structure and the second planar electrode are mounted on the connecting electrode in some embodiments of the present invention;

[0050] Fig. 9 is a schematic diagram of the structure of a pressure ring in some embodiments of the present invention;

[0051] Fig.10 is a schematic diagram of a structure in which a compression spring assembly is mounted on a compression ring in some embodiments of the present invention;

[0052] Fig.11 is a schematic diagram of the structure of a compression spring assembly in some embodiments of the present invention;

[0053] Fig.12 is a longitudinal cross-sectional view of a compression spring assembly in some embodiments of the present invention;

[0054] Fig.13 is a schematic diagram of the structure of an ultrasonic sensor of the present invention in which a main control board is installed in a housing in some embodiments;

[0055] Fig.14 4 is a cross-sectional view of the structure of the ultrasonic sensor of the present invention in some embodiments in which the back cover is installed on the outer shell.

[0056] Reference numerals:

[0057] Ultrasonic sensor 100;

[0058] First planar electrode 1; insulating film 11; first conductive layer 12;

[0059] Second planar electrode 2; conductive substrate 21; insulating layer 22; silk screen layer 221;

[0060] Shell 3; first end 31; communication port 311; second end 32; supporting portion 33; second sealing ring 331; limiting block 34; first clamping block 35; second clamping block 36; limiting groove 37; third clamping block 38;

[0061] Connecting electrode 4; through slot 41; through hole pad 42;

[0062] Pressing structure 5; pressing ring 51; ring body 511; first ring segment 5111; second ring segment 5112; elastic channel 512; channel end wall 5121; avoidance groove 513; accommodating area 514; injection position 515; buckle 516; head 5161; foot 5162; shoulder 5163; clamping position 517; protrusion 518; first mounting groove 519; protrusion 520; sealing member 53;

[0063] Compression spring assembly 6; trunk 61; first elastic portion 62; first contact surface 621; first fixing portion 63; buckle section 631; slot 632; second fixing portion 64; groove 65; convex shaft 66; wing portion 67; second elastic portion 68; second contact surface 681; contact portion 682; connecting portion 683;

[0064] Main control board 7; avoidance gap 71; two-pin plug wire 72; avoidance opening 73; wire 74;

[0065] Back cover 8; back plate 81; cylindrical portion 82; positioning groove 821; boss 83; sealing ring 84; nut 85; elastic washer 86; rubber sleeve 87; screw tube 88;

[0066] Net cover 9; Card slot 91. DETAILED DESCRIPTION

[0067] In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are provided to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may also be implemented in other embodiments without these specific details.

[0068] Example 1

[0069] See also Figure 1 The present invention constructs an ultrasonic sensor 100, which is a capacitive ultrasonic sensor 100, which at least includes a first planar electrode 1 and a second planar electrode 2, wherein the first planar electrode 1 and the second planar electrode 2 are opposite to each other and at least partially attached to each other, but are insulated; the first planar electrode 1 and the second planar electrode 2 form a planar capacitor, and an electric field can be formed between the two.

[0070] When a pulse electric field or an alternating electric field of a certain frequency is applied to the planar capacitor, the first planar electrode 1 may vibrate up and down to generate ultrasonic waves, which are emitted to the side of the first planar electrode 1 away from the second planar electrode 2. Alternatively, the first planar electrode 1 vibrates under the action of external ultrasonic waves, and the capacitance value formed between the first planar electrode 1 and the second planar electrode 2 will change with the vibration, thereby generating a detectable electrical signal.

[0071] The ultrasonic sensor 100 of the present invention utilizes the first planar electrode 1 and the second planar electrode 2 to cooperate with each other to replace the piezoelectric ceramic sheet to form a planar capacitor, thereby avoiding the technical defects caused by the production technology of the piezoelectric ceramic sheet, and the manufacturing process of the first planar electrode 1 is convenient, low in cost, high in yield, and conducive to rapid manufacturing. Secondly, by using a capacitive ultrasonic transducer, the ultrasonic wave can obtain a narrower beam angle.

[0072] The first planar electrode 1 is a planar structure (see Figure 3 ), and the shape is circular. Of course, the shape of the first planar electrode 1 can also be other shapes, which are not specifically limited here.

[0073] In some embodiments, the first planar electrode 1 may be a metal film; it is understandable that the better the flexibility of the metal and the thinner the thickness, the better the sensitivity of the ultrasonic sensor 100, and different thicknesses may correspond to different ultrasonic frequencies.

[0074] In some more preferred embodiments, Figure 1 As shown, the first planar electrode 1 may include an insulating film 11, and a first conductive layer 12 disposed on the surface of the insulating film 11 facing the second planar electrode 2. Optionally, the thickness of the insulating film 11 may range from 1 μm to 50 μm, preferably from 5 μm to 20 μm, such as 8 μm, 10 μm, 12.5 μm, 15 μm, 18 μm; and the thickness of the first conductive layer 12 may range from 1 nm to 20 μm, such as 100 nm, 0.5 μm, 1 μm, 5 μm. Optionally, the insulating film 11 may be a plastic film, and the material of the plastic film may be one of PC material, PVC material, ABS material, PE material, PP material, BOPP material, PET material and polyethylene material, or a combination of at least two of the above materials. The first conductive layer 12 may be a metal layer, and the material of the metal layer may include aluminum, gold and copper.

[0075] It is understandable that if a metal film is directly used as the first planar electrode 1, the crystal phase structure of the metal film will become brittle at sub-zero temperatures (such as between -40°C and 0°C), so the metal crystal structure will change at low temperatures, the vibration of its lattice will be reduced, and the spacing between atoms will be reduced, making it easier for metal atoms to move, resulting in reduced plasticity and toughness of the metal material, so the performance of the first planar electrode 1 made of a metal film is slightly worse. In addition, the crystal structure of the metal will also undergo a phase change at low temperatures, and it will change from a face-centered cubic structure to a body-centered cubic structure, further weakening the plasticity and toughness of the metal, resulting in reduced vibration performance and sensitivity of the film.

[0076] In this preferred embodiment, by attaching a metal layer on the plastic film, not only the electrical properties of the metal layer but also the mechanical properties of the plastic film are utilized, so that the first planar electrode 1 has both excellent sensitivity and better life and weather resistance.

[0077] See also Figure 2 The second planar electrode 2 may be a circular planar structure. Of course, its shape may also be other shapes, preferably matching the shape of the first planar electrode 1 .

[0078] Read again Figure 1 The second planar electrode 2 may include a conductive substrate 21, and an insulating layer 22 disposed on the side of the conductive substrate 21 facing the first planar electrode 1, and the insulating layer 22 is used to achieve insulation between the second planar electrode 2 and the first planar electrode 1. Of course, the insulating layer 22 may also be disposed on the side of the first conductive layer 12 of the first planar electrode 1 that is away from the insulating film 11, and this is not specifically limited. The insulating layer 22 only needs to be disposed between the first conductive layer 12 and the conductive substrate 21 to play an insulating isolation role. Preferably, the surface of the insulating layer 22 facing the first planar electrode 1 is arranged in a concave-convex manner to effectively avoid vacuum adsorption between the second planar electrode 2 and the first planar electrode 1.

[0079] In some embodiments, the conductive substrate 21 may include a plate body, and a second conductive layer (not shown) disposed on the surface of the plate body facing the first planar electrode 1. The insulating layer 22 is disposed on the surface of the second conductive layer facing the first planar electrode 1. Optionally, the conductive substrate 21 may be a PCB (Printed Circuit Board), and the second conductive layer may be a copper sheet laid on the PCB; wherein the PCB may be a double-layer board or a four-layer board.

[0080] Optionally, the conductive substrate 21 is a conductive metal plate; optionally, the thickness of the metal plate ranges from 0.001 mm to 20 mm; the greater the thickness of the metal plate, the higher the sensitivity of the ultrasonic sensor; preferably, the thickness is between 0.8 mm and 2 mm. The insulating layer 22 is disposed on the surface of the metal plate facing the first planar electrode 1.

[0081] It is understandable that the PCB circuit board is conducive to the rapid, efficient and low-cost manufacture of the second planar electrode 2 due to its mature manufacturing process; and the metal plate contains more metal atoms than the PCB circuit board and can store more charges. When the metal plate is used to manufacture the second planar electrode 2, the sensitivity of the ultrasonic sensor can be relatively higher.

[0082] In some embodiments, the insulating layer 22 may include an insulating oil layer coated on the conductive substrate 21 and / or a silk-screen layer 221 silk-screened on the conductive substrate 21 (see Figure 2 ).

[0083] Alternatively, if Figure 2 As shown, the insulating layer 22 includes an insulating oil layer (not shown) laid on the conductive substrate 21, and a silk-screen layer 221 printed on the insulating oil layer. There is a step in the thickness direction between the silk-screen layer 221 and the insulating oil layer; for example, the shape of the silk-screen layer 221 can be a plane figure arranged at intervals, such as a plurality of concentric circles, a plurality of concentric rectangles, a plurality of parallel vertical stripes, etc., or can be vertical stripes arranged in a staggered manner to form a step.

[0084] It can be understood that the insulating oil layer and the silk-screen layer 221 form double insulation, which can enhance the reliability of insulation. Because the insulating oil layer is thin, such as the green oil layer, it is easy to be damaged over time, resulting in insulation failure; on the other hand, the height difference between the silk-screen layer 221 and the surface of the insulating oil layer can effectively avoid the vacuum adsorption effect between the second planar electrode 2 and the first planar electrode 1, because if the second planar electrode 2 and the first planar electrode 1 are vacuum adsorbed, it will cause excessive adhesion between the second planar electrode 2 and the first planar electrode 1, affecting the vibration effect.

[0085] like Figure 2 As shown, in this embodiment, the surface of the second planar electrode 2 facing away from the first planar electrode 1 may be provided with a pad electrically connected to the second conductive layer for connecting to a power source. Of course, the surface of the second planar electrode 2 facing the first planar electrode 1 may also be provided.

[0086] In summary, the first planar electrode 1 and the second planar electrode 2 are firmly attached to each other and contact each other, but are not short-circuited with each other, so as to form a stable planar capacitor.

[0087] When put into use, the second planar electrode 2 can be used as the positive electrode and the first planar electrode 1 can be used as the negative electrode, and the two can be connected to the two ends of the power supply respectively; for example, the ultrasonic sensor 100 also includes two electrode wires connected to the power supply, one end of one electrode wire can be mechanically and electrically connected to the pad on the second planar electrode 2, and one end of the other electrode wire can be directly / indirectly electrically connected to the first planar electrode 1. Of course, the polarity of the second planar electrode 2 and the first planar electrode 1 can be interchanged.

[0088] Subsequently, a pulse electric field or an alternating electric field of a certain frequency is applied to the first planar electrode 1 and the second planar electrode 2, and the first planar electrode 1 vibrates up and down to generate ultrasonic waves. In particular, when the first planar electrode 1 is made by attaching a metal layer on a plastic film, the applied voltage change can drive the metal layer to vibrate. At this time, since the metal layer is tightly attached to the plastic film, the plastic film vibrates together with it, thereby driving the air molecules to generate ultrasonic waves; and this method of making the first planar electrode 1 can obtain better performance than the method of directly using a metal film to make the first planar electrode 1 mentioned above. It can be understood that because the side of the first planar electrode 1 facing the outside world is the surface of the plastic film, the first planar electrode 1 can be more corrosion-resistant, and because the molecular bond of the plastic film is not affected at low temperatures, the first planar electrode 1 can be more resistant to low temperatures, and the ultrasonic sensor 100 can work normally even at minus 40°C.

[0089] Secondly, the diameters of the first planar electrode 1 and the second planar electrode 2 can be determined according to the requirements. For example, the diameters of the first planar electrode 1 and the second planar electrode 2 can be increased to make the ultrasonic sensor 100 more sensitive, because the capacitance can obtain a larger capacitance as the area of ​​the positive and negative electrodes increases. Alternatively, the diameter between the first planar electrode 1 and the second planar electrode 2 can be reduced to meet the requirements of miniaturization of the ultrasonic sensor 100.

[0090] Example 2

[0091] See also Figure 3 and Figure 4 In this embodiment, the ultrasonic sensor 100 of the present invention includes, in addition to the first planar electrode 1 and the second planar electrode 2 described in the embodiment, a housing 3, a connecting electrode 4, a pressing structure 5, a compression spring assembly 6, a main control board 7, a back cover 8 and a mesh cover 9. Of course, these components are not necessary components for the ultrasonic sensor 100 to generate ultrasonic waves, but they are applied in this embodiment as a preferred solution.

[0092] It can be understood that the shell 3 is used to provide an installation and protection basis for the first planar electrode 1 and the second planar electrode 2, the connecting electrode 4 is used to make the first planar electrode 1 conductive, the pressing structure 5 is used to tightly fit the connecting electrode 4 to the first planar electrode 1, the compression spring assembly 6 is used to firmly fit the first planar electrode 1 and the second planar electrode 2 together, the main control board 7 is at least used to provide a suitable power supply for the first planar electrode 1 and the second planar electrode 2, the back cover 8 is used to seal the open end of the shell 3, and the mesh cover 9 is used to protect the first planar electrode 1.

[0093] See also Figure 5 , a supporting portion 33 is provided in the housing 3 for supporting the first planar electrode 1; at the same time, the housing 3 is also provided with a communication port 311 communicating with the outside world, and when the first planar electrode 1 is placed on the supporting portion 33, it can face the communication port 311; and the insulating film 11 of the first planar electrode 1 can block the communication port 311 to separate the outside world from the first conductive layer 12. Since the first conductive layer 12 is isolated from the outside world, it is difficult for external factors to affect the first conductive layer 12, so the corrosion resistance and life of the first conductive layer 12 are improved; especially when the insulating film 11 is a plastic film, the ultrasonic sensor 100 can have good waterproof and anti-corrosion properties.

[0094] In some embodiments, the housing 3 may be in a tubular shape, such as a cylindrical shape, and may include a first end 31 and a second end 32 opposite to the first end 31 , and both the first end 31 and the second end 32 are open.

[0095] For the convenience of description of this solution, the position of the first end 31 or the position biased toward the first end 31 is regarded as the bottom, and the position of the second end 32 or the position biased toward the second end 32 is regarded as the top. Of course, the position biased toward the first end 31 can also be regarded as the top, and the position biased toward the second end 32 can also be regarded as the bottom, which is not limited here.

[0096] The supporting portion 33 is annular and is located at the bottom of the housing 3; the communication port 311 is formed at the bottom of the housing 3. A second sealing ring 331 is also embedded on the supporting portion 33 to prevent glue from flowing out from the bottom of the housing 3 during glue pouring (see below).

[0097] A stopper 34 may be provided in the housing 3 to prevent the connection electrode 4 from rotating randomly, and effectively ensure that the connection electrode 4 is relatively fixed to the first planar electrode 1. Optionally, the stopper 34 is provided on the inner peripheral side of the housing 3 and is located at the top of the supporting portion 33.

[0098] A plurality of first clamping blocks 35 may also be provided in the housing 3, which are arranged at intervals in the circumferential direction on the inner circumferential side of the housing 3, and are used to cooperate with the pressing structure 5 so that the pressing structure 5 is pressed tightly against the connecting electrode 4. In this embodiment, four first clamping blocks 35 are provided in the housing 3, which are located above the supporting portion 33. Of course, the number of the first clamping block 35 can be at least one, as long as the contact area between the first clamping block 35 and the pressing structure 5 is sufficient to stabilize the pressing structure 5.

[0099] A plurality of second card blocks 36 may also be provided in the housing 3, which are arranged at intervals on the inner peripheral side of the housing 3, and are used to cooperate with the back cover 8 to provide a mounting base for the back cover 8 to be fixedly mounted on the top of the housing 3. The second card blocks 36 are located above the plurality of first card blocks 35, and are spaced apart from the plurality of first card blocks 35 in the longitudinal direction. In this embodiment, four second card blocks 36 are provided in the housing 3. Optionally, the length of the second card block 36 is equal to or less than the length of the first card block 35.

[0100] The top end wall of the shell 3 may also be provided with a limiting groove 37 for cooperating with the back cover 8 to prevent the back cover 8 from rotating at will, thereby effectively ensuring that the back cover 8 can be relatively fixed to the shell 3 after being installed on the shell 3.

[0101] See also Figure 6 , Figure 6 The assembly relationship between the first planar electrode 1 and the housing 3 is shown. It should be noted that for the convenience of viewing the figure, Figure 6 The shell 3 of FIG. 3 only shows a partial structure, and the same is true for some of the drawings mentioned below, which will not be specifically described below. The diameter of the first planar electrode 1 is larger than the inner diameter of the supporting portion 33 and smaller than the inner diameter of the shell 3. The first planar electrode 1 is placed flatly on the supporting portion 33.

[0102] See also Figure 7 The connecting electrode 4 is placed on the top of the first planar electrode 1, attached to and electrically connected to the first conductive layer 12 of the first planar electrode 1, and the connecting electrode 4 also plays the role of pressing the first planar electrode 1 on the supporting portion 33, so that the first planar electrode 1 and the supporting portion 33 are attached together. Secondly, the assembled connecting electrode 4 is located below the first card blocks 35, and there is a distance between each first card block 35 in the longitudinal direction.

[0103] like Figure 7 As shown, the connecting electrode 4 may be annular, such as a circular ring, whose outer diameter matches the inner diameter of the housing 3, and whose inner diameter is smaller than the diameter of the first planar electrode 1; the connecting electrode 4 may be coaxially arranged with the first planar electrode 1 during assembly. The connecting electrode 4 may be made of a conductive metal material, such as aluminum, copper, or gold. Of course, the connecting electrode 4 is not limited to being made of a conductive material, and it may also be achieved by plating a conductive coating on the outer surface of a non-conductive body. The material of the conductive coating may be aluminum, copper, gold, and the like.

[0104] The connecting electrode 4 may be provided with a plurality of through slots 41, the number of which matches the number of the first clamping block 35 and the second clamping block 36, wherein any through slot 41 is formed at the outer edge of the connecting electrode 4 through the upper and lower surfaces. During assembly, the connecting electrode 4 is inserted into the outer shell 3 from the second end 32 of the outer shell 3, and through the through slots 41, the connecting electrode 4 can smoothly pass over the first clamping block 35 and the second clamping block 36 to reach the top of the first planar electrode 1; and one of the through slots 41 can be inserted into the limit block 34 of the outer shell 3 to limit the displacement of the connecting electrode 4 in the circumferential direction, effectively protecting the first planar electrode 1 from relative displacement during the assembly process, thereby ensuring the integrity of the first planar electrode 1. In this embodiment, the connecting electrode 4 is provided with four through slots 41, which are located at the periphery of the connecting electrode 4.

[0105] The connecting electrode 4 may also be provided with a through-hole pad 42 for mechanically and electrically connecting with the electrode line to achieve connection between the first planar electrode 1 and the main control board 7. In this embodiment, the through-hole pad 42 is in the shape of a semicircular hole and is located at the periphery of the connecting electrode 4.

[0106] Please combine Figure 4 and Figure 8 For reference, the pressing structure 5 is placed on the top of the connecting electrode 4 to press the first planar electrode 1 and the connecting electrode 4 tightly in the housing 3 and ensure that the first planar electrode 1 and the connecting electrode 4 are firmly attached together.

[0107] The compression structure 5 may be annular as a whole, such as a circular ring, whose maximum outer diameter matches the inner diameter of the housing 3 , and whose inner diameter is greater than or equal to the inner diameter of the connecting electrode 4 .

[0108] The compression structure 5 may include a compression ring 51 and a sealing member 53 embedded in the bottom of the compression ring 51. Of course, the sealing member 53 is not a necessary component of the compression structure 5, but is applied in this embodiment as a preferred solution to play a sealing role, such as preventing liquid leakage.

[0109] See also Fig. 9 The pressure ring 51 may include a ring body 511, which is used to provide a basis for pressing the first planar electrode 1 and the connecting electrode 4; a buckle structure for clamping the ring body 511 above the connecting electrode 4 is also provided between the ring body 511 and the inner wall of the shell 3.

[0110] For reference Figure 8 , Fig. 9The buckle structure may include a plurality of elastic channels 512 formed on the outer periphery of the ring body 511, and the first card block 35 mentioned above. The plurality of elastic channels 512 can be used for each of the first card block 35 and the second card block 36 to pass through in a one-to-one correspondence when the pressure ring 51 is assembled; wherein, the upper end opening diameter of the elastic channel 512 is smaller than the length of the first card block 35, but the side wall of the elastic channel 512 has elastic deformation ability, which allows the first card block 35 to pass through smoothly, and after the first card block 35 passes through, the elastic channel 512 can return to its original state; the channel end wall 5121 formed around the upper end opening abuts against the first card block 35, and the ring body 511 is restricted between the connecting electrode 4 and the first card block 35.

[0111] Secondly, the thickness from the channel end wall 5121 to the bottom of the seal 53 (in the natural state) is greater than or equal to the height distance between the first clamping block 35 and the connecting electrode piece, so as to play a role in pressing the first planar electrode 1 and the connecting electrode piece. In the embodiment where the seal 53 is not provided, the thickness from the end wall to the bottom of the ring body 511 is greater than or equal to the height distance between the first clamping block 35 and the connecting electrode piece.

[0112] The elastic deformation capability can be that the side wall of the elastic channel 512 tilts completely after being stressed, and returns to its original state after being withdrawn; that is, the side walls of the elastic channel 512 on opposite sides will be stretched open by the first clamping block 35, so that the side walls on both sides tilt away from each other. Of course, the elastic deformation capability can also be that the side wall of the elastic channel 512 at the stress position is concave and deformed, and returns to its original state after being withdrawn; that is, the side wall of the elastic channel 512 is an elastic wall, and the part of the side wall of the elastic channel 512 abutted by the first clamping block 35 will be concave and deformed.

[0113] Alternatively, if Fig. 9 As shown, the ring body 511 is also provided with a plurality of avoidance grooves 513, which are respectively located below each elastic channel 512 and are connected to the opening of the lower end (i.e., the end close to the first planar electrode 1) of the elastic channel 512, so as to allow the first block 35 to pass through and enter the elastic channel 512. The length of the avoidance groove 513 is greater than or equal to the length of the first block 35. Of course, the avoidance grooves 513 are not necessary features of the pressure ring 51; in an embodiment where the avoidance grooves 513 are not provided, the lower end of the elastic channel 512 can be directly extended to the corresponding position.

[0114] Alternatively, if Fig. 9As shown, the ring body 511 is also provided with a receiving area 514 above each elastic channel 512, the receiving area 514 is communicated with the upper end opening of the elastic channel 512, and is used to receive the first block 35 passing through the elastic channel 512, and the side wall of the receiving area 514 cooperates with the first block 35 to limit the displacement of the ring body 511 in the circumferential direction, which is conducive to the stability of the installation position of the first planar electrode 1. The length of the receiving area 514 is preferably equivalent to the length of the first block 35.

[0115] Alternatively, if Fig. 9 As shown, one or more glue injection positions 515 are also provided on the ring body 511 to fill one or more gaps formed by at least two combinations of the housing 3, the pressure ring 51, the seal 53, the connecting electrode 4 and the first planar electrode 1. Understandably, the mouth of the glue injection tube filled with glue can be extended into the glue injection position 515 for glue injection. The glue flows into each gap under the action of gravity. After the glue solidifies, the first planar electrode 1 can be firmly adhered. Otherwise, the first planar electrode 1 cannot withstand the fitting pressure from the second planar electrode 2 and falls off. It can also ensure that the surface of the first planar electrode 1 is basically flat. The fitting pressure given by the second planar electrode 2 is also conducive to the flatness of the planar electrode surface. If there are wrinkles on the first planar electrode 1, it will affect the generation of ultrasonic waves. In addition, the glue can further prevent the pressure ring 51 from rotating and loosening, improve reliability, and at the same time improve the waterproof performance, so that the protection effect of the entire sensor is better and the structure is stronger. Preferably, the glue may be a polyurethane potting glue with good fluidity and viscosity, and the polyurethane potting glue has high hardness after solidification.

[0116] In some embodiments, Fig. 9 As shown, the ring body 511 may include a first ring segment 5111 and a second ring segment 5112, the first ring segment 5111 is located above the second ring segment 5112, that is, the first ring segment 5111 is farther away from the first planar electrode 1 than the second ring segment 5112, and the outer diameter of most structures in the first ring segment 5111 is smaller than the outer diameter of the second ring segment 5112; secondly, the inner diameter of the first ring segment 5111 may be equal to the inner diameter of the second ring segment 5112.

[0117] A plurality of avoidance grooves 513 are formed at intervals in the circumferential direction on the second ring segment 5112. In this embodiment, four avoidance grooves 513 are provided, which are evenly distributed on the second ring segment 5112.

[0118] A plurality of groups of buckle assemblies are arranged circumferentially at intervals on the first ring segment 5111, and each group of buckle assemblies is used to form an elastic channel 512. Further, any group of buckle assemblies may include two buckle members 516 arranged symmetrically at intervals along the circumference of the ring body 511, and an elastic channel 512 is formed between the two buckle members 516.

[0119] The elastic channel 512 is provided with a first opening (equivalent to the lower end opening mentioned above, not marked in the figure) and a second opening (equivalent to the upper end opening mentioned above, not marked in the figure) opposite to the first opening, wherein the first opening is located below the second opening, that is, the first opening is closer to the first end 31 of the housing 3 relative to the second opening. The width of the first opening is greater than or equal to the length of the first block 35, and the second opening is smaller than the width of the first opening and smaller than the length of the first block 35. Preferably, in order to facilitate the passage of the first block 35, the two buckles 516 are each used to form a side wall of the elastic channel 512 that is at least partially smoothly inclined.

[0120] The snap-on component 516 has a head 5161, a foot 5162 and a shoulder 5163 between the head 5161 and the foot 5162. The foot 5162 is fixedly connected to the top of the second ring segment 5112 (equivalent to the snap-on component 516 standing in the middle of the thickness of the ring body 511, which is conducive to the miniaturization of the entire sensor). The head 5161 is located above the foot 5162, and the shoulder 5163 protrudes along one side of the snap-on component 516 adjacent to another snap-on component 516, and can form a step together with the head 5161. The top wall of the shoulder 5163 is equivalent to the above-mentioned channel end wall 5121. The interval between the feet 5162 of the two clips 516 of the same group forms a first opening, the length of which is greater than or equal to the length of the first card block 35, and is preferably equivalent to the length of the avoidance groove 513; the interval between the shoulders 5163 of the two forms a second opening, the length of which is less than the length of the first card block 35; at the same time, the interval between the heads 5161 of the two forms a accommodating area 514, the length of which is greater than the length of the second opening and equivalent to the length of the first card block 35; the first card block 35 after passing through the elastic channel 512 is located in the accommodating area 514, and cooperates with the heads 5161 and shoulders 5163 of the two clips 516 to prohibit the ring body 511 from displacing in the circumferential and longitudinal directions.

[0121] like Fig. 9 As shown, the first ring segment 5111 is provided with a groove at the position of each fastener 516, wherein a distance is maintained between the side wall of the groove and the peripheral side of the fastener 516, thereby forming a glue injection position 515, and the glue injection position 515 is located at the peripheral side of the fastener 516. It can be understood that the advantage of forming the glue injection position 515 at the peripheral side of the fastener 516 is that the fastener 516 can be fixed after the glue is cured, so that the first clamping block 35 can no longer pass through the elastic channel 512.

[0122] Continue reading Fig. 9 The pressure ring 51 also includes at least one latching position 517 formed on the outer periphery of the ring body 511 for the main control board 7 to be latched in, thereby limiting the displacement of the main control board 7 in the circumferential direction of the pressure ring 51 .

[0123] In some embodiments, Fig. 9 As shown, the ring body 511 is provided with a protrusion 518 between two adjacent elastic channels 512, and the protrusion 518 and the fastener 516 used to form one of the elastic channels 512 together form a latching position 517. In order to leave enough space for the main control board 7 to be latched, the protrusion 518 tends to be biased toward one of the elastic channels 512, and forms a latching position 517 with the fastener 516 used to form the other elastic channel 512. In this embodiment, two protrusions 518 are provided on the ring body 511, and the two protrusions 518 are respectively located on opposite sides of the ring body 511, and both stand on the top of the second ring segment 5112, thereby forming two latching positions 517. It can be understood that the present invention uses the fastener 516 and the protrusion 518 to cooperate to form the latching position 517, which is conducive to the simplification of the structure of the pressure ring 51.

[0124] Preferably, the protrusion 518 is in an inverted L-shape, the vertical section of the protrusion 518 stands on the ring body 511, and the transverse section of the protrusion 518 extends in the direction of the locking position 517; the transverse section can limit the longitudinal separation of the main control board 7 from the locking position 517, which is beneficial to the stability of the installation of the main control board 7.

[0125] The pressure ring 51 may also include a wire passing position (not marked in the figure) arranged on the outer periphery of the ring body 511 for the electrode wire to extend to the main control board 7.

[0126] Continue reading Fig. 9 The compression ring 51 may also include a first mounting groove 519 and a second mounting groove (not shown) provided on opposite sides of the ring body 511, for providing a mounting base for the compression spring assembly 6. It can be understood that the provision of two mounting grooves (i.e., the first mounting groove 519 and the second mounting groove) in the present invention is not intended to limit the number of mounting grooves; more than three mounting grooves may be provided according to the structure of the compression spring assembly 6, or one mounting groove may be provided, for example, one end of the compression spring assembly 6 is installed in the mounting groove, and the other end thereof may be tightly against the inner peripheral side wall of the ring body 511.

[0127] In some embodiments, Fig. 9 As shown, the first mounting groove 519 can be in an arc column shape, of course, it can also be in other shapes, as long as it is compatible with the compression spring assembly 6. The first mounting groove 519 is formed by being recessed inward along the top of the ring body 511, and has a first notch located at the top of the ring body 511 and a second notch located at the inner side wall of the ring body 511; secondly, the two inner side walls of the first mounting groove 519 located in the circumferential direction of the pressure ring 51 are respectively provided with protrusions 520, which are used to cooperate with the compression spring assembly 6 to prevent the compression spring assembly 6 from loosening, and there is a distance between the protrusion 520 and the bottom of the first mounting groove 519 and the inner side wall of the first mounting groove 519 on the outside.

[0128] The second mounting groove is at the same height as the first mounting groove 519 and is formed by being recessed along the inner wall of the ring body 511. In this embodiment, the second mounting groove can be a square groove having surrounding groove walls and a notch formed on the inner wall of the ring body 511.

[0129] Of course, the structures of the first installation slot 519 and the second installation slot may also be the same, which depends on the installation method of the compression spring assembly 6 .

[0130] Optionally, the outer surface of the ring body 511 at the first installation groove 519 and the second installation groove 632 protrudes from the outer surface of the second ring segment 5112 so that the glue can flow to the gap.

[0131] Can be reviewed Figure 3 The seal 53 is annular and is embedded in a ring groove (not shown) formed by the inward depression at the bottom of the ring body 511. In this embodiment, the ring groove is formed in the second ring segment 5112. After the seal 53 is embedded in the ring body 511, it can partially overflow and be deformed by being squeezed during the assembly process of the pressure ring 51, so that the seal 53 is fully in contact with the connecting electrode, thereby ensuring the sealing effect. Optionally, the seal 53 can be a silicone ring.

[0132] Please read back Figure 8 The diameter of the second planar electrode 2 is smaller than or equal to the inner diameter of the pressure ring 51 . The second planar electrode 2 is installed in the central through hole of the pressure ring 51 and fits with the first planar electrode 1 .

[0133] See also Fig.10 The compression spring assembly 6 is placed on the top of the second planar electrode 2 to firmly attach the second planar electrode 2 to the first planar electrode 1. Optionally, the compression spring assembly 6 can be made of plastic material, which has a simple structure, easy assembly, low cost, and is particularly suitable for mass production.

[0134] The compression spring assembly 6 can be fixedly installed on the compression ring 51, and the installed compression spring assembly 6 may not be higher than the top of the ring body 511 of the compression ring 51. Optionally, a clamping structure is provided between at least one side of the compression spring assembly 6 and the compression ring 51 to fixedly install the compression spring assembly 6 on the compression ring 51. In this embodiment, a first clamping structure and a second clamping structure are respectively provided between the opposite sides of the compression spring assembly 6 and the compression ring 51. The first clamping structure and the second clamping structure may be the same structure or different structures, which is not limited here.

[0135] For example, see Fig.11 and Fig.12The compression spring assembly 6 may include a longitudinal main body 61 and a first elastic portion 62 located on the side of the main body 61 facing the second planar electrode 2. The first elastic portion 62 has elastic deformation capability. When the main body 61 is fixed on one side of the second planar electrode 2, the first elastic portion 62 is in a compressed state to compress the first planar electrode 1 and the second planar electrode 2.

[0136] like Fig.10 As shown, the first clamping structure includes a first fixing portion 63 arranged on one side of the main body 61, and the above-mentioned first mounting groove 519; the first fixing portion 63 can be buckled into the first mounting groove 519, and is limited by the protrusion 520 in the first mounting groove 519, so that the first fixing portion 63 cannot escape from the first mounting groove 519 independently.

[0137] Alternatively, if Fig.11 As shown, the first fixing portion 63 may include two snap-in sections 631 extending outward along one side of the main body 61, and the two snap-in sections 631 are spaced apart along the width direction of the main body 61 and have elastic deformation capability, and each snap-in section 631 is provided with a slot 632 for cooperating with the protrusion 520 of the first mounting groove 519, and the slot 632 is recessed along the top of the snap-in section 631, and has a third notch located at the top of the snap-in section 631, and a fourth notch located in the side wall of the snap-in section 631 facing the corresponding protrusion 520. During the assembly process, a force may be applied to the first fixing portion 63 to bring the two buckle segments 631 closer together, and the first fixing portion 63 may be installed in the first mounting groove 519 of the pressure ring 51. Then, the force applied to the first fixing portion 63 is removed, and the two buckle segments 631 are reset due to the disappearance of the external force. At the same time, under the action of the elastic force of the first elastic portion 62, the first fixing portion 63 moves upward, and the protrusion 520 in the first mounting groove 519 enters the groove 632 on the buckle segment 631 (see Fig.10 ), preventing the first fixing portion 63 from detaching from the first mounting groove 519. It is understandable that in a high temperature environment (such as a high temperature experiment or actual use scenario), the compression spring assembly 6 is subject to the elastic force of the first elastic member, and there is a risk of deformation, while the sawtooth locking structure (i.e. the protrusion 520 and the slot 632 mentioned above) can prevent the first fixing portion 63 from deforming and falling out, thereby improving the reliability of the structure. Of course, the position of the protrusion 520 on the first mounting groove 519 and the position of the slot 632 on the buckle section 631 can be changed as needed, and no specific limitation is made here. For example, the protrusion 520 can be set on the outer wall of the first mounting groove 519, and correspondingly, the slot 632 is located on the top of the end of the buckle section 631.

[0138] The second clamping structure includes a second fixing portion 64 (see Fig.12), and the second mounting groove mentioned above. The second fixing portion 64 can be inserted into the second mounting groove and abut against the groove wall of the second mounting groove. Optionally, the second fixing portion 64 is a latch. It can be understood that when assembling the entire compression spring assembly 6, the second fixing portion 64 is first directly inserted into the second mounting groove, and then the first fixing portion 63 is buckled into the first mounting groove 519. The entire installation process is very simple and can be operated with one hand.

[0139] See also Fig.11 The first elastic part 62 has a first contact surface 621 for contacting the second planar electrode 2, and it includes a natural state and a deformed state. The natural state is that there is a distance between the first contact surface 621 and the plane where the main body 61 is located. The deformed state is that the first elastic part 62 is deformed, and the first contact surface 621 is displaced toward the plane where the main body 61 is located, so that the distance between the first contact surface 621 and the plane where the main body 61 is located is shortened, thereby generating an elastic force, and the direction of the elastic force is away from the plane where the main body 61 is located.

[0140] Alternatively, if Fig.11 As shown, the first elastic part 62 can be a tower spring, that is, a pagoda-shaped spring, one end of which is fixedly connected to the side of the main body 61 facing the second planar electrode 2, and the other end of which is used to abut the second planar electrode 2. It can be understood that the elastic force of the tower spring is relatively more stable, and the elastic effect is better, and the force size is better controlled. In addition, the tower spring in a compressed state can form a planar structure, occupying a very small space, and is more suitable for products such as the ultrasonic sensor 100 that require a small volume.

[0141] In this option, continue to see Fig.11 The main body 61 is formed with an annular groove 65 on one side facing the second planar electrode 2, and one end of the tower spring can be sleeved and fixed on the groove 65. Preferably, the inner periphery of the groove 65 is provided with a protruding shaft 66, and wing portions 67 are provided on at least two sides of the protruding shaft 66, the wing portions 67 are located below the groove 65, and the projection of the wing portions 67 can fall on the groove 65, so as to limit the tower spring from escaping from the groove 65. In this embodiment, two wing portions 67 are provided, which are located on opposite sides of the protruding shaft 66.

[0142] Alternatively, the first elastic portion 62 is a longitudinal arc-shaped spring piece (not shown), and the arc surface facing the second planar electrode 2 is the first contact surface 621. The two ends of the arc-shaped spring piece are respectively combined with the main body 61, and the connecting line of the two ends is parallel to / coincides with the length direction of the main body 61. Secondly, in this optional solution, the main body 61 can be provided with a slot (not shown) at the corresponding position of the arc-shaped spring piece to avoid the deformed arc-shaped spring piece; at least most of the structure of the arc-shaped spring piece in a compressed state is accommodated in the slot, which is conducive to reducing the overall thickness of the sensor.

[0143] Please combine Fig.11 , Fig.12 For reference, the compression spring assembly 6 may further include two second elastic parts 68 located on both sides of the trunk 61 in the width direction and connected to the trunk 61. The second elastic part 68 has elastic deformation capability, is used to contact the second planar electrode 2, and deforms after contact, and applies downward pressure in the direction of the second planar electrode 2. It can be understood that the first elastic part 62 is used to press down the middle position of the second planar electrode 2, and the second elastic part 68 is used to press down the outer position of the second planar electrode 2 located outside the middle position.

[0144] Any second elastic part 68 is provided with a second contact surface 681 for contacting the second planar electrode 2. The second elastic part 68 includes a natural state and a deformed state. The natural state is that the second contact surface 681 is located between the main body 61 and the second planar electrode 2, and has a distance from the plane where the main body 61 is located. The deformed state is that the second elastic part 68 is deformed, and the second contact surface 681 is relatively displaced in the direction of the plane where the main body 61 is located. The distance between the second contact surface 681 and the plane where the main body 61 is located is shortened, thereby generating an elastic force. The elastic force is the downward pressure mentioned above, and its direction is away from the plane where the main body 61 is located.

[0145] Alternatively, if Fig.12 As shown, the second elastic portion 68 may include a contact portion 682 and two connecting portions 683 combined at both ends of the contact portion 682. The contact portion 682 is used to abut the second planar electrode 2, and its surface facing the second planar electrode 2 is the second contact surface 681. The contact portion 682 is located below the plane where the main body 61 is located in a natural state. The connecting portion 683 is used to connect the contact portion 682 and the main body 61, and the connecting portion 683 can meander downward from the main body 61 and gradually extend in the direction of the connecting portion 683.

[0146] It should be noted that the number of the connecting portion 683 can be at least one. In an embodiment where one connecting portion 683 is provided, one end of the connecting portion 683 can be fixedly connected to the middle of the main body 61 , and the other end thereof can be connected to the contact portion 682 .

[0147] See also Fig.13 , the main control board 7 is installed on the top of the pressure ring 51; after assembly, the main control board 7 is located above the compression spring assembly 6.

[0148] In some embodiments, a third clamping structure is provided between the main control board 7 and the pressure ring 51 to fixedly install the main control board 7 on the pressure ring 51. Optionally, the outer peripheral edge of the main control board 7 is provided with a plurality of avoidance notches 71 arranged at intervals in the circumferential direction, and the third clamping structure may include a spacing structure between the main control board 7 and two adjacent avoidance notches 71, and the above-mentioned clamping position 517; the formed multiple spacing structures are at least partially used to be clamped into the clamping position 517, and at the same time, the avoidance notch 71 can allow the main control board 7 to pass through the first clamping block 35 and the second clamping block 36 smoothly. Optionally, the spacing structure may be an arc-shaped sheet structure, and its length in the circumferential direction is equivalent to the circumferential length of the clamping position 517.

[0149] See also Fig.13 The sensor can be electrically connected to the second planar electrode 2 and the first planar electrode 1 by using a two-pin plug wire 72, and a connection port for inserting the plug of the two-pin plug wire 72 is provided on the main control board 7, so as to facilitate the connection between the main control board 7 and the second planar electrode 2 and the first planar electrode 1. The positive and negative terminals on one side of the two-pin plug wire 72 are respectively welded to the second planar electrode 2 and the first planar electrode 1, and the plug on the other side is directly inserted into the main control board 7.

[0150] The main control board 7 is provided with a plurality of circuit components, which are used to form a boost circuit, a signal amplification and processing circuit, a communication circuit, a main control chip, etc. It should be noted that the specific circuit component structure can refer to the prior art and will not be described in detail here. Secondly, the main control board 7 can also be provided with an avoidance opening 73 for the electrode line to pass through.

[0151] See also Fig.14 The back cover 8 is installed on the second end 32 of the shell 3 and blocks the second end 32 of the shell 3. The installation method can be interference fit, screw connection, clamping connection, etc.

[0152] like Fig.14 As shown, the back cover 8 may include a back plate 81 and a cylindrical portion 82 arranged on the back plate 81. The outer surface of the cylindrical portion 82 is provided with a plurality of locking grooves 821 for cooperating with the second locking block 36 in the outer shell 3 to fixedly install the back cover 8 in the outer shell 3.

[0153] The shape of the positioning groove 821 may be L-shaped, and may include a fifth notch for the second clamping block 36 to enter, and an inner groove located on one side of the fifth notch in the circumferential direction of the cylindrical portion 82, connected to the fifth notch, and used to limit the second clamping block 36 from being separated from the notch. It can be understood that before the back cover 8 is installed, the position of the fifth notch is aligned with the position of the second clamping block 36, and then the back cover 8 can be smoothly installed in the housing 3, and the second clamping block 36 can be relatively moved to the inner groove by rotating.

[0154] Continue reading Fig.14The back plate 81 is used to connect to the cylindrical portion 82 and is provided with a boss 83 at its surface edge. After the back cover 8 is installed in the shell 3, the boss 83 can enter the limiting groove 37 of the shell 3 to prevent the back cover 8 from rotating and loosening, and ensure that it is assembled in place.

[0155] The outer circumference of the cylindrical portion 82 may be sleeved with one or more sealing rings 84 for sealing, such as waterproofing.

[0156] Please read back Figure 3 , Figure 4 , the ultrasonic sensor 100 also includes mounting accessories for fixing the wire 74 connected to the main control board 7. In this embodiment, the mounting accessories may include a nut 85, an elastic washer 86, a rubber sleeve 87, a screw 88 and a nut (not shown). It can be understood that the nut, the elastic washer 86, the rubber sleeve 87, the screw 88, the nut 85 and the wire 74 are arranged in the position shown in the figure, the elastic washer 86 is sleeved on the lower end of the screw 88, the rubber sleeve 87 is sleeved into the screw 88, the nut 85 is lightly rotated, the assembled screw 88 is installed on the top of the back cover 8, and its lower end passes through the back cover 8 and is fixed on the back cover 8 with a nut, the wire 74 passes through the screw 88 and is welded on the main control board 7, of course, a plug can also be provided at the end of the wire 74, which is directly inserted into the socket on the main control board 7 to facilitate connection with the main control board 7.

[0157] Continue reading Figure 3 The mesh cover 9 is detachably mounted on the first end 31 of the housing 3. The mesh cover 9 is provided with a plurality of mesh holes for facilitating ultrasonic emission. It is understandable that the mesh cover 9 is applied to the present embodiment as a preferred solution. The mesh cover 9 can prevent fingers from touching the film to play a protective role, and can also drain water through the mesh holes; in other embodiments, the mesh cover 9 may be selected not to be installed, which can be selected according to the sensitivity requirements of the ultrasonic sensor. For example, the mesh cover 9 may be removed when the ultrasonic sensor needs to be more sensitive.

[0158] A fixing structure is provided between the mesh cover 9 and the housing 3 to fix the mesh cover 9 on the housing 3. Optionally, as Figure 3 As shown, the fixing structure may include a plurality of third clamping blocks 38 arranged circumferentially at intervals on the outer periphery of the first end 31 of the housing 3, and a plurality of clamping slots 91 arranged circumferentially at intervals on the mesh cover 9, and the clamping slots 91 may be buckled into the third clamping blocks 38 one by one, so that the mesh cover 9 is fixed to the first end 31 of the housing 3. The shape of the clamping slot 91 matches the shape of the third clamping block 38, wherein the clamping slot 91 has a notch for the third clamping block 38 to enter, the notch is formed at the top edge of the mesh cover 9, and the length of the notch is less than the length of the bottom wall of the clamping slot 91.

[0159] Of course, the fixing structure is not limited to the above structure. For example, the fixing structure may include an external thread (not shown) arranged on the peripheral side of the first end 31 of the shell 3, and an internal thread (not shown) arranged on the peripheral side of the mesh cover 9.

[0160] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. An ultrasonic sensor, characterized in that: It comprises a first planar electrode (1) and a second planar electrode (2) which are arranged opposite to each other; the first planar electrode (1) and the second planar electrode (2) are at least partially attached to each other and are insulated from each other to form a stable planar capacitor; The first planar electrode (1) comprises an insulating film (11) and a first conductive layer (12) arranged on a side of the insulating film (11) facing the second planar electrode (2); the second planar electrode (2) comprises a conductive substrate (21); An insulating layer (22) is further provided between the first conductive layer (12) and the conductive substrate (21).

2. The ultrasonic sensor according to claim 1, characterized in that: The insulating film (11) is a plastic film, and the thickness of the insulating film (11) is in the range of 1 μm to 50 μm; The first conductive layer (12) is a metal layer attached to the surface of the plastic film, and the thickness of the first conductive layer (12) is in the range of 1 nm to 20 μm.

3. The ultrasonic sensor according to claim 1, characterized in that: The conductive substrate (21) is a PCB circuit board, and the PCB circuit board is provided with a second conductive layer located on a side facing the first planar electrode (1); Alternatively, the conductive substrate (21) is a metal plate, and the thickness of the metal plate is in the range of 0.001 mm to 20 mm.

4. The ultrasonic sensor according to claim 1, characterized in that: The insulating layer (22) is arranged on a side of the conductive substrate (21) facing the first planar electrode (1), and the surface of the insulating layer (22) facing the first planar electrode (1) is arranged in a concave-convex manner; Alternatively, the insulating layer (22) is arranged on a side of the first conductive layer (12) facing away from the insulating film (11), and the insulating layer (22) is arranged in a concave-convex manner on a surface facing the second planar electrode (2).

5. The ultrasonic sensor according to any one of claims 1 to 4, characterized in that: The ultrasonic sensor comprises a housing (3), wherein the housing (3) is provided with a supporting portion (33) located therein, and a communication port (311) communicating with the outside; The first planar electrode (1) is placed on the supporting portion (33) and is arranged opposite to the communication port (311); wherein the insulating film (11) isolates the first conductive layer (12) from the outside world.

6. The ultrasonic sensor according to claim 5, characterized in that: The ultrasonic sensor further comprises a connecting electrode (4) located on a side of the first planar electrode (1) facing away from the supporting portion (33), wherein the connecting electrode (4) is attached to the first conductive layer (12) and is electrically connected to the first conductive layer (12); The ultrasonic sensor further comprises a pressure ring (51) arranged in the housing (3), the pressure ring (51) being in contact with a surface of the connecting electrode (4) on a side facing away from the first planar electrode (1); and a snap-fit ​​structure is provided between the pressure ring (51) and the housing (3) to press the connecting electrode (4) and the first planar electrode (1) onto the supporting portion (33).

7. The ultrasonic sensor according to claim 6, characterized in that: The buckle structure comprises a plurality of elastic channels (512) arranged circumferentially on the pressure ring (51), and a plurality of first clamping blocks (35) arranged on the inner circumference of the housing (3) and corresponding one-to-one to the plurality of elastic channels (512); The side wall of any of the elastic channels (512) has elastic deformation capability, and the width of the opening of the elastic channel (512) away from the connecting electrode (4) is smaller than the length of the first clamping block (35); The pressure ring (51) uses the elasticity of the side wall of the elastic channel (512) to pass over the first block (35) and is assembled between the first block (35) and the connecting electrode (4); wherein the channel end wall (5121) formed around the opening abuts against the first block (35).

8. The ultrasonic sensor according to claim 7, characterized in that: The pressure ring (51) is also provided with a receiving area (514) located on the side of the elastic channel (512) away from the connecting electrode (4); a first clamping block (35) passing through the elastic channel (512) is located in the receiving area (514) and can abut against the side wall of the receiving area (514) to limit the displacement of the pressure ring (51) in the circumferential direction.

9. The ultrasonic sensor according to claim 8, characterized in that: The pressure ring (51) comprises a ring body (511) and a plurality of groups of buckle assemblies arranged at intervals in the circumferential direction around the ring body (511); any group of buckle assemblies comprises two buckle members (516) arranged at intervals in the circumferential direction of the ring body (511), and the elastic channel (512) and the accommodating area (514) are formed between the two buckle members (516); Wherein, the deformation state of the elastic channel (512) is that the two locking members (516) are respectively inclined in directions away from each other; or, the side walls of the two locking members (516) facing each other are elastic walls.

10. The ultrasonic sensor according to claim 9, characterized in that: The pressure ring (51) is provided with a plurality of injection positions (515) for injecting glue, so that the glue is solidified and formed in one or more gaps formed by at least two combinations of the housing (3), the pressure ring (51), the connecting electrode (4) and the first planar electrode (1); each of the injection positions (515) is correspondingly formed on the circumference of each of the buckling parts (516).

11. The ultrasonic sensor according to claim 6, characterized in that: The ultrasonic sensor comprises a compression spring assembly (6), which is relatively fixed to the side of the second planar electrode (2) facing away from the first planar electrode (1) and abuts against the second planar electrode (2), exerting a force on the second planar electrode (2) to make it close to the first planar electrode (1).

12. The ultrasonic sensor according to claim 11, characterized in that: The compression spring assembly (6) comprises a main body (61) and a first elastic part (62) between two ends of the main body (61); the first elastic part (62) has elastic deformation capability and is in a compressed state to achieve compression when the main body (61) is fixed to one side of the second planar electrode (2).

13. The ultrasonic sensor according to claim 12, characterized in that: The first elastic part (62) is a tower spring, one end of which is connected to the main body (61), and the other end of which abuts against the second planar electrode (2); Alternatively, the first elastic portion (62) is a longitudinally long arc-shaped elastic piece, and the arc-shaped elastic piece protrudes from one side of the main body (61).

14. The ultrasonic sensor according to claim 13, characterized in that: A first clamping structure and a second clamping structure are respectively provided between the two opposite sides of the main body (61) and the pressure ring (51) to fix the compression spring assembly (6) on the pressure ring (51).

15. The ultrasonic sensor according to claim 14, characterized in that: The first clamping structure comprises a first fixing portion (63) arranged on one side of the main body (61), and a first mounting groove (519) arranged on the pressure ring (51); the first fixing portion (63) comprises two buckle sections (631), the two buckle sections (631) extend outward along one side of the main body (61), and are spaced apart from each other; the two buckle sections (631) have elastic deformation capability, and in a deformed state, they move closer to each other to enter the first mounting groove (519), and are clamped in the first mounting groove (519) in a natural state; And / or, the second clamping structure comprises a second fixing portion (64) arranged on the other side of the main body (61), and a second mounting groove arranged on the pressure ring (51); the second fixing portion (64) is inserted into the second mounting groove.

16. The ultrasonic sensor according to claim 15, characterized in that: A locking structure is also provided between each of the buckle sections (631) and the groove wall of the first installation groove (519) to prevent the buckle section (631) from falling out of the first installation groove (519).

17. The ultrasonic sensor according to claim 16, characterized in that: Any of the locking structures comprises a slot (632) arranged at the top of the buckle section (631), and a protrusion (520) arranged on the groove wall of the first mounting groove (519); the slot (632) is buckled on the protrusion (520) after the buckle section (631) enters the first mounting groove (519).

18. The ultrasonic sensor according to claim 12, characterized in that: The compression spring assembly (6) further comprises two second elastic parts (68) respectively located on both sides of the main body (61) in the width direction; The second elastic portion (68) has elastic deformation capability and is in a deformed state to achieve compression when the main body (61) is fixed to the second planar electrode (2).

19. The ultrasonic sensor according to claim 18, characterized in that: Each of the second elastic parts (68) comprises a contact part (682) for abutting against the electrode sheet, and a connecting part (683) for connecting the contact part (682) to the main body (61); There is a distance between the contact portion (682) and the plane where the main body (61) is located. After the contact portion (682) is abutted, the end of the connecting portion (683) connected to the contact portion (682) is relatively displaced in the direction of the plane where the main body (61) is located to generate elastic force.

20. The ultrasonic sensor according to claim 5, characterized in that: The ultrasonic sensor further comprises a mesh cover (9) which is detachably mounted on an end of the housing (3) close to the first planar electrode (1); A fixing structure is provided between the mesh cover (9) and the outer shell (3) so as to fix the mesh cover (9) on the outer shell (3).

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