A sensor

Abstract

The application discloses a sensor, which comprises a shell with a mounting hole, a matching layer embedded on the inner wall of the mounting hole, and a piezoelectric ceramic sheet installed on the matching layer; the matching layer has a groove, and the piezoelectric ceramic sheet is installed on the bottom wall of the groove. The application can increase the sensitivity, reduce the residual vibration, improve the performance of the sensor, and belongs to the technical field of detection devices.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of detection devices, and in particular to a sensor. BACKGROUND

[0002] The sweeping robot is generally provided with an ultrasonic high-frequency sensor for material identification, and in particular when identifying the ground material, the ultrasonic high-frequency sensor of the sweeping robot needs very high sensitivity. In the traditional technology, increasing the sensitivity of the high-frequency sensor often brings about the redundant vibration of the sensor, commonly known as the residual vibration, which affects the identification ability of the sensor. SUMMARY

[0003] In view of the technical problems existing in the prior art, the purpose of the present application is to provide a sensor which can increase the sensitivity while reducing the residual vibration and improve the performance of the sensor.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0005] A sensor comprises a shell with a mounting hole, a matching layer embedded on the inner wall of the mounting hole, and a piezoelectric ceramic sheet mounted on the matching layer; the matching layer has a groove, and the piezoelectric ceramic sheet is mounted on the bottom wall of the groove.

[0006] Further, the sensor further comprises a first damping layer, a second damping layer, a printed circuit board, a potting adhesive layer, an outer lead wire, a first inner lead wire, and a second inner lead wire; the first damping layer, the second damping layer, and the printed circuit board are located in the groove and are connected in sequence, the piezoelectric ceramic sheet is clamped between the first damping layer and the bottom wall of the groove, the potting adhesive layer is located in the mounting hole and is connected with the printed circuit board, the piezoelectric ceramic sheet has a positive electrode and a negative electrode, one end of the first inner lead wire is connected with the positive electrode of the piezoelectric ceramic sheet, one end of the second inner lead wire is connected with the negative electrode of the piezoelectric ceramic sheet, the other end of the first inner lead wire and the other end of the second inner lead wire are both connected with the printed circuit board, and the printed circuit board is connected with the outer lead wire.

[0007] Further, the bottom wall of the groove is provided with a welding point groove, the positive electrode of the piezoelectric ceramic sheet is provided with a positive welding point, the negative electrode of the piezoelectric ceramic sheet is provided with a negative welding point, the negative welding point is located in the welding point groove, and the welding point groove is filled with a patch adhesive.

[0008] Further, one end of the outer lead wire is located outside the shell, and the other end of the outer lead wire is inserted into the potting adhesive layer and connected with the printed circuit board.

[0009] Further, the outer lead wire is provided with a terminal.

[0010] Further, the sensor further comprises a rubber ring; the mounting hole comprises a first hole section, a second hole section and a third hole section which are sequentially communicated; the first hole section, the second hole section and the third hole section sequentially increase in diameter, the first hole section and the second hole section are connected and have a first hole shoulder, the second hole section and the third hole section are connected and have a second hole shoulder, the matching layer is provided with a clamping block, the clamping block is abutted on the inner wall of the second hole section, the rubber ring is annularly arranged on the inner wall of the third hole section and is abutted on the second hole shoulder, and the clamping block is clamped between the rubber ring and the first hole shoulder.

[0011] Further, the potting adhesive layer is located in the first hole section.

[0012] Further, the side wall of the groove is provided with a limiting block, and the printed circuit board is clamped between the potting adhesive layer and the limiting block.

[0013] Further, the first damping layer is an integral piece made of silicone rubber, and the second damping layer is an integral piece made of epoxy resin.

[0014] Further, the matching layer is integrally formed.

[0015] Compared with the prior art, the present application has the advantages that the present application has simple structure and low production cost. The matching layer of the present application is integrally formed, the groove bottom wall of the matching layer is provided with a soldering point groove, the soldering point groove can accommodate a negative soldering point and a second inner connecting wire, the upper end face and the lower end face of the piezoelectric ceramic sheet can be used as positive and negative electrodes respectively, the full electrode of the piezoelectric ceramic sheet is used to emit and receive signals, the sensitivity of the sensor is increased, the side wall of the matching layer is formed as a stepped portion, the rubber ring sleeved on the matching layer can increase the inward binding force, reduce the vibration of the side wall, and further reduce the influence of residual vibration. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic view of the sensor.

[0017] Figure 2 is a structural schematic view of the shell.

[0018] Figure 3 is a structural schematic view of the matching layer.

[0019] Figure 4 is a structural schematic view of the rubber ring.

[0020] In the figure, 1 is a shell, 2 is a matching layer, 3 is a piezoelectric ceramic sheet, 4 is a first damping layer, 5 is a second damping layer, 6 is a printed circuit board, 7 is a potting glue layer, 8 is an external wire, 9 is a first internal wire, 10 is a second internal wire, 11 is a patch glue, 12 is a terminal, 13 is a rubber ring, 101 is a mounting hole, 201 is a groove, 202 is a block, 203 is a limit block, 204 is a solder point groove, 301 is a positive solder point, 302 is a negative solder point, 130 is a glue filling area, 1011 is a first hole section, 1012 is a second hole section, 1013 is a third hole section, 1014 is a first hole shoulder, and 1015 is a second hole shoulder. DETAILED DESCRIPTION

[0021] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0022] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0023] For the convenience of description, unless otherwise specified, the up and down directions mentioned below are the same as Figure 1 The up and down directions are consistent with the Figure 1 The left and right directions of the Figure 1 The left and right directions are consistent.

[0024] like Figures 1 to 4 As shown, this embodiment provides a sensor, including a shell 1 having a mounting hole 101, a matching layer 2 embedded on the inner wall of the mounting hole 101, and a piezoelectric ceramic piece 3 mounted on the matching layer 2; the mounting hole 101 is located in the central area of ​​the shell 1 and passes through the shell 1 from top to bottom, and the lower end of the mounting hole 101 is isolated from the outside of the shell 1 by the matching layer 2. The matching layer 2 has a groove 201, and the matching layer 2 is U-shaped. The piezoelectric ceramic piece 3 is mounted on the bottom wall of the groove 201, and the piezoelectric ceramic piece 3 is located in the groove 201. The piezoelectric ceramic piece 3 is fixed in the groove 201 of the matching layer 2, and the matching layer 2 is embedded and fixed in the shell 1. The sensor structure is relatively stable and effectively reduces residual vibration. The inner wall of the groove 201 can block the piezoelectric ceramic piece 3, preventing the piezoelectric ceramic piece 3 from hitting the inner wall of the shell 1 when vibrating, further reducing the impact of residual vibration.

[0025] Specifically, in one embodiment, the matching layer 2 in the shape of U is integrally formed by an injection molding process.

[0026] Specifically, in one embodiment, the sensor further comprises a first damping layer 4, a second damping layer 5, a printed circuit board 6, a potting layer 7, an outer lead 8, a first inner lead 9, and a second inner lead 10; the first damping layer 4, the second damping layer 5, and the printed circuit board 6 are located in the groove 201 and connected in sequence, the piezoelectric ceramic wafer 3 is clamped between the first damping layer 4 and the bottom wall of the groove 201, the potting layer 7 is located in the mounting hole 101 and connected with the printed circuit board 6, the piezoelectric ceramic wafer 3 has a positive electrode and a negative electrode, one end of the first inner lead 9 is connected with the positive electrode of the piezoelectric ceramic wafer 3, one end of the second inner lead 10 is connected with the negative electrode of the piezoelectric ceramic wafer 3, the other end of the first inner lead 9 and the other end of the second inner lead 10 are both connected with the printed circuit board 6, and the printed circuit board 6 is connected with the outer lead 8. The first damping layer 4, the second damping layer 5, and the printed circuit board 6 are all located in the groove 201 of the matching layer 2, and are arranged in sequence from bottom to top. The potting layer 7 is filled in the mounting hole 101 above the matching layer 2.

[0027] The traditional sensor adopts a single damping layer, which can suppress the vibration of the piezoelectric ceramic wafer 3. In the present embodiment, a double damping layer is adopted, the first damping layer 4 can separate the second damping layer 5 and the piezoelectric ceramic wafer 3, and through the first damping layer 4 and the second damping layer 5, the beneficial vibration of the sensor can not be lost too much, which can effectively reduce the residual vibration without suppressing the vibration of the piezoelectric ceramic wafer 3.

[0028] Specifically, in one embodiment, the piezoelectric ceramic wafer 3 is pasted on the bottom wall of the groove 201 by the patch glue 11, and the left and right ends of the piezoelectric ceramic wafer 3 are connected with the side wall of the groove 201 by the patch glue 11.

[0029] Specifically, in one embodiment, the bottom wall of the groove 201 is provided with a welding point groove 204, the negative and positive electrodes of the traditional flange electrode are both on the same surface, which can sacrifice the relative area of the positive and negative electrodes, the vibration can be reduced, but the amplitude can also be reduced, which can affect the performance of the sensor. The piezoelectric ceramic wafer 3 of the present application is a full electrode, the upper end surface of the piezoelectric ceramic wafer 3 is a positive electrode, and the lower end surface of the piezoelectric ceramic wafer 3 is a negative electrode, which can ensure the relative area of the positive and negative electrodes, so that the full electrode has a large amplitude and a small vibration, the piezoelectric ceramic wafer 3 transmits and receives signals by the full electrode, which can increase the sensitivity of the probe, thereby improving the recognition performance of the sensor. The positive electrode of the piezoelectric ceramic wafer 3 is provided with a positive welding point 301, and the negative electrode of the piezoelectric ceramic wafer 3 is provided with a negative welding point 302, the negative welding point 302 is located in the welding point groove 204, and the welding point groove 204 is filled with the patch glue 11.

[0030] Specifically, in one embodiment, one end of the outer conductor 8 is located outside the shell 1, and the other end of the outer conductor 8 is inserted into the potting layer 7 and connected with the printed circuit board 6. The central region of the printed circuit board 6 is provided with a wiring hole in communication with the second damping layer 5, the first inner conductor 9, and the second inner conductor 10 pass through the wiring hole and are connected with the upper end surface of the printed circuit board 6.

[0031] Specifically, in one embodiment, the outer conductor 8 located outside the shell 1 is provided with a terminal 12. The model of the terminal 12 is A1501H-2F.

[0032] Specifically, in one embodiment, the sensor further comprises a rubber ring 13; the mounting hole 101 comprises a first hole section 1011, a second hole section 1012, and a third hole section 1013 which are sequentially communicated; the first hole section 1011, the second hole section 1012, and the third hole section 1013 are sequentially arranged from top to bottom, and the diameters of the first hole section 1011, the second hole section 1012, and the third hole section 1013 increase sequentially; the connection between the first hole section 1011 and the second hole section 1012 is provided with a first hole shoulder 1014, the connection between the second hole section 1012 and the third hole section 1013 is provided with a second hole shoulder 1015, the outer side surface of the matching layer 2 is annularly provided with a clamping block 202, the side surface of the clamping block 202 abuts against the inner wall of the second hole section 1012, the rubber ring 13 is annularly arranged on the inner wall of the third hole section 1013, and the upper end of the rubber ring 13 abuts against the second hole shoulder 1015, and the outer circumferential side surface of the rubber ring 13 abuts against the inner wall of the third hole section 1013. The rubber ring 13 is sleeved on the outer side of the matching layer 2, the rubber ring 13 is clamped between the outer side of the matching layer 2 and the inner wall of the third hole section 1013, and the clamping block 202 is clamped between the upper end surface of the rubber ring 13 and the first hole shoulder 1014. The rubber ring 13 is a silica gel sleeve, and the rubber ring 13 can increase the inward binding force and reduce the vibration of the side wall.

[0033] Specifically, in one embodiment, the potting layer 7 is located in the first hole section 1011, and the potting layer 7 is filled in the first hole section 1011.

[0034] Specifically, in one embodiment, the side wall of the groove 201 is provided with a limiting block 203, and the limiting block 203 is annularly arranged on the inner wall of the groove 201. The printed circuit board 6 is clamped between the potting layer 7 and the limiting block 203. The lower end surface of the printed circuit board 6 abuts against the upper end surface of the limiting block 203, there is a gap between the upper end surface of the printed circuit board 6 and the upper end surface of the matching layer 2, the upper end surface of the printed circuit board 6 is provided with a welding point, the welding point is located in the gap, and the gap and the upper part of the gap are filled with the potting layer 7.

[0035] Specifically, in one embodiment, the first damping layer 4 is an integral piece made of silicone rubber, and the second damping layer 5 is an integral piece made of epoxy resin. The material of the first damping layer 4 in contact with the piezoelectric ceramic sheet 3 is silicone rubber, and the material of the second damping layer 5 adjacent to the silicone rubber is epoxy resin. The first damping layer 4 of silicone rubber can prevent the upper epoxy resin layer from being in contact with the piezoelectric ceramic sheet 3, thereby reducing the loss of beneficial vibration. The hardness of the first damping layer 4 is greater than that of the second damping layer 5, and the silicone rubber can also be replaced by other media with higher hardness than the epoxy resin.

[0036] Specifically, in one embodiment, the thickness of the first damping layer 4 is less than that of the second damping layer 5, and the thickness of the first damping layer 4 gradually decreases from the edge region to the central region. The first damping layer 4 is in contact with the piezoelectric ceramic sheet 3. When the piezoelectric ceramic sheet 3 vibrates, the amplitude of the edge of the piezoelectric ceramic sheet 3 is greater than that of the central region of the piezoelectric ceramic sheet 3. The thickness of the first damping layer 4 gradually decreases from the edge region to the central region, which can make the amplitudes of the edge and the central region of the piezoelectric ceramic sheet 3 consistent, thereby increasing the sensitivity of the sensor and ensuring the performance of the sensor.

[0037] Specifically, in one embodiment, the rubber ring 13 is annular, the outer circumferential side of the rubber ring 13 is divided into a fitting part and a sealing part, the fitting part is located above the sealing part, the sealing part abuts against the inner wall of the third hole section 1013 of the mounting hole 101, the fitting part and the inner wall of the third hole section 1013 jointly form a rubber filling area 130, a plurality of spherical protrusions are arranged on the side wall of the fitting part, the rubber filling area 130 is filled with rubber, and the fitting part of the rubber ring 13 is attached to the inner wall of the third hole section 1013 through the rubber.

[0038] The assembly method of the application comprises the following steps: first, printing electrodes on the upper and lower ends of the silver sheet, and then leading out positive and negative welding points, thereby obtaining a piezoelectric ceramic sheet. Second, preferentially attaching the negative electrode to the groove bottom wall of the matching layer, aligning the negative welding point with the welding point groove of the groove bottom wall, and pre-filling the welding point groove of the groove bottom wall with patch glue, which has a predetermined positioning effect on the piezoelectric ceramic sheet. Third, after placing the piezoelectric ceramic sheet, laying the first and second inner connecting wires and sequentially coating the first and second damping layers; covering the second damping layer with a PCB (printed circuit board), laying the outer wire, and finally filling the potting glue layer. Fourth, sleeving the rubber ring on the outer side wall of the matching layer. Fifth, clamping the probe on the shell.

[0039] The above description is only the preferred embodiments of the application, and it should be pointed out that those skilled in the art can make some improvements and replacements without departing from the technical principles of the application, and these improvements and replacements should also be considered as the protection scope of the application.

Claims

1. A sensor, characterized by: The shell includes a mounting hole, a matching layer embedded on the inner wall of the mounting hole, and a piezoelectric ceramic sheet mounted on the matching layer; the matching layer has a groove, and the piezoelectric ceramic sheet is mounted on the bottom wall of the groove; The piezoelectric ceramic sheet is further provided with a positive electrode and a negative electrode, one end of a first inner lead is connected with the positive electrode of the piezoelectric ceramic sheet, one end of a second inner lead is connected with the negative electrode of the piezoelectric ceramic sheet, the other end of the first inner lead and the other end of the second inner lead are both connected with the printed circuit board, and the printed circuit board is connected with an outer lead.

2. The sensor of claim 1, wherein: The bottom wall of the groove is provided with a welding point groove, the positive electrode of the piezoelectric ceramic sheet is provided with a positive welding point, the negative electrode of the piezoelectric ceramic sheet is provided with a negative welding point, the negative welding point is located in the welding point groove, and the welding point groove is filled with a patch adhesive.

3. A sensor according to claim 2, wherein: One end of the outer lead is located outside the shell, and the other end of the outer lead is inserted into the potting adhesive layer and connected with the printed circuit board.

4. The sensor of claim 2, wherein: The outer lead is provided with a terminal.

5. The sensor of claim 2, wherein: The mounting hole includes a first hole section, a second hole section and a third hole section which are sequentially connected, the diameters of the first hole section, the second hole section and the third hole section increase sequentially, the first hole section and the second hole section are connected at a first hole shoulder, the second hole section and the third hole section are connected at a second hole shoulder, a clamping block is annularly arranged on the matching layer and abuts against the inner wall of the second hole section, a rubber ring is annularly arranged on the inner wall of the third hole section and abuts against the second hole shoulder, and the clamping block is clamped between the rubber ring and the first hole shoulder.

6. The sensor of claim 2, wherein: The potting adhesive layer is located in the first hole section.

7. A sensor according to claim 6, characterised in that: The printed circuit board is clamped between the potting adhesive layer and the limiting block.

8. The sensor of claim 2, wherein: The matching layer is integrally formed.

9. A sensor according to any one of claims 1 to 8, wherein: The matching layer is integrally formed.

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