Knock sensor

Abstract

The invention discloses a knocking sensor, and belongs to the technical field of sensors, and the knocking sensor comprises a housing which is internally provided with a cavity; the piezoelectric film is arranged in the accommodating cavity; the PCBA board is limited in the accommodating cavity, and the PCBA board is used for pressing the piezoelectric film on the bottom surface of the accommodating cavity, so that the piezoelectric film is attached to the bottom surface of the accommodating cavity; the piezoelectric film is configured to generate piezoelectric signals according to vibration of the shell, the PCBA board is electrically connected with the piezoelectric film, the PCBA board is configured to process the piezoelectric signals to generate detection signals and transmit the detection signals, and the knocking sensor has the advantages of being high in sensitivity and accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and particularly to a tapping sensor. Background Art

[0002] Currently, electrical appliances usually use buttons to control electrical equipment. When a user presses a button, the button sends a button signal to the electrical equipment, and the electrical equipment performs corresponding actions according to the button signal. However, with the continuous upgrading and improvement of electrical equipment, a function of controlling electrical equipment by tapping the electrical equipment has gradually emerged. Therefore, how to detect the vibration signal when the electrical equipment is tapped is a technical problem that needs to be solved urgently at present. Summary of the Invention

[0003] The purpose of the present invention is to provide a tapping sensor to solve the above problems.

[0004] To achieve this purpose, the present invention adopts the following technical solutions:

[0005] A tapping sensor, comprising:

[0006] A housing, an accommodation cavity is formed inside the housing;

[0007] A piezoelectric film, the piezoelectric film is disposed in the accommodation cavity;

[0008] A PCBA board, the PCBA board is restricted in the accommodation cavity, and the PCBA board presses the piezoelectric film against the bottom surface of the accommodation cavity so that the piezoelectric film is in contact with the bottom surface of the accommodation cavity;

[0009] The piezoelectric film is configured to generate a piezoelectric signal according to the vibration of the housing, the PCBA board is electrically connected to the piezoelectric film, and the PCBA board is configured to process the piezoelectric signal to generate a detection signal and transmit the detection signal.

[0010] Preferably, a plurality of locking teeth are provided on the inner wall of the accommodation cavity, and the plurality of locking teeth jointly restrict the PCBA board in the accommodation cavity.

[0011] Preferably, a vibration relief groove is provided at the bottom of the accommodation cavity, and the vibration relief groove corresponds to a part of the piezoelectric film.

[0012] Preferably, one end of the piezoelectric film is provided with a pin, the piezoelectric film is electrically connected to the PCBA board through the pin, the pin is bent downward and forms an angle with the PCBA board, and the PCB board presses the piezoelectric film against the bottom surface of the accommodation cavity by applying force to the pin.

[0013] Preferably, the PCBA board is provided with a signal transmission module, and the PCBA board transmits the detection signal to an external electrical device through the signal transmission module.

[0014] Preferably, at least one side of the housing has a connecting portion, and the housing is fixed to an external electrical device through the connecting portion.

[0015] Preferably, the PCBA board is provided with an asymmetric notch, and a limiting strip corresponding to the notch one by one is arranged in the cavity.

[0016] Preferably, a potting adhesive is further included, and the potting adhesive is used to fix the PCBA board and the piezoelectric film in the cavity.

[0017] Preferably, the signal transmission module is a terminal block.

[0018] Preferably, the angle between the pin and the PCBA board is 1° to 20°.

[0019] One embodiment of the present invention has the following beneficial effects:

[0020] 1. When external vibration is transmitted to the housing, since the piezoelectric film is in contact with the bottom surface of the cavity, the vibration of the housing is transmitted to the piezoelectric film through the bottom surface of the cavity. When the piezoelectric film vibrates, the piezoelectric film generates a piezoelectric signal, and the PCBA board processes the electrical signal into a detection signal and transmits the detection signal outward;

[0021] 2. By pressing the piezoelectric film on the bottom surface of the cavity through the PCBA board, the structure of the knock sensor can be made more compact, and the overall volume is smaller, which is beneficial to the space utilization of the electrical device; in addition, the piezoelectric film can be directly welded to the PCBA board, thereby reducing the use of wires, with lower costs, and since the piezoelectric film is directly connected to the PCBA board, the signal transmission distance is reduced, so the signal interference and loss are smaller;

[0022] 3. Placing both the piezoelectric film and the PCBA board in the cavity of the housing makes the knock sensor an integrated structure, which is more convenient to install. Description of the Drawings

[0023] The drawings further illustrate the present invention, but the content in the drawings does not constitute any limitation to the present invention.

[0024] Figure 1 is a schematic three-dimensional structure diagram of one embodiment of the present invention;

[0025] Figure 2 is a schematic cross-sectional structure diagram of one embodiment of the present invention;

[0026] Figure 3It is a front view structural schematic diagram of the connection between a piezoelectric thin film and a PCBA board according to one embodiment of the present invention;

[0027] Figure 4 It is a bottom view structural schematic diagram of the connection between a piezoelectric thin film and a PCBA board according to one embodiment of the present invention;

[0028] Figure 5 It is a three-dimensional structural schematic diagram of a housing according to one embodiment of the present invention;

[0029] In the drawings: 1 - housing, 11 - cavity, 12 - engaging teeth, 13 - vibration relief groove, 14 - connecting portion, 15 - limiting strip, 2 - piezoelectric thin film, 21 - pin, 3 - PCBA board, 31 - notch, 32 - terminal. Detailed Embodiment

[0030] The following details the embodiments of the present invention. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention. In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0031] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a connection that can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include indirect contact between the first and second features through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the horizontal height of the first feature is less than that of the second feature.

[0033] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0034] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific embodiments.

[0035] A knock sensor according to this embodiment, as Figures 1-5 shown, includes:

[0036] A housing 1, an accommodation cavity 11 is formed inside the housing 1;

[0037] A piezoelectric film 2, the piezoelectric film 2 is disposed inside the accommodation cavity 11;

[0038] A PCBA board 3, the PCBA board 3 is restricted inside the accommodation cavity 11, and the PCBA board 3 presses the piezoelectric film 2 against the bottom surface of the accommodation cavity 11 so that the piezoelectric film 2 is in contact with the bottom surface of the accommodation cavity 11;

[0039] The piezoelectric film 2 is configured to generate a piezoelectric signal according to the vibration of the housing 1, the PCBA board 3 is electrically connected to the piezoelectric film 2, and the PCBA board 3 is configured to process the piezoelectric signal to generate a detection signal and transmit the detection signal.

[0040] In actual use, the knock sensor of the present invention is installed on the inner wall of the knock area of the electrical appliance, such as the inner wall of the panel of the electrical appliance, the inner wall of the housing of the electrical appliance, etc. The specific installation position depends on the specific electrical appliance and the function to be achieved. Taking an embedded dishwasher as an example, in order to make the embedded dishwasher have a better overall effect with the cabinet, the embedded dishwasher can cancel the setting of the door handle and automatically push the door panel out at a certain angle when the panel of the embedded dishwasher is knocked. Therefore, it is necessary to detect the knock signal at the panel of the embedded dishwasher. Thus, the knock sensor can be fixed on the inner wall of the panel of the embedded dishwasher. When the panel of the embedded dishwasher is knocked, the vibration of the panel will be transmitted to the housing 1 of the knock sensor, and then the knock signal of the panel can be accurately detected. Embodiment of the present invention applied to other electrical appliances will not be elaborated one by one.

[0041] When the external vibration is transmitted to the housing 1, since the piezoelectric film 2 is attached to the bottom surface of the cavity 11, the vibration of the housing 1 is transmitted to the piezoelectric film 2 through the bottom surface of the cavity 11. When the piezoelectric film 2 vibrates, the piezoelectric film 2 generates a piezoelectric signal. The PCBA board 3 processes the electrical signal into a detection signal and transmits the detection signal outward. For example, the PCBA board 3 actively sends the detection signal to an external electrical appliance, or the external electrical appliance actively obtains the detection signal of the PCBA; in the present invention, the piezoelectric film 2 is pressed against the bottom surface of the cavity 11 by the PCBA board 3, which can make the structure of the knock sensor more compact and the overall volume smaller, facilitating the space utilization of the electrical appliance; in addition, the piezoelectric film 2 can be directly welded to the PCBA board 3, thus reducing the use of wires, with lower cost, and since the piezoelectric film 2 is directly connected to the PCBA board 3, the signal transmission distance is reduced, so the signal interference and loss are smaller; moreover, in the present invention, both the piezoelectric film 2 and the PCBA board 3 are placed in the cavity 11 of the housing 1, making the knock sensor an integral structure and more convenient to install.

[0042] Further, a plurality of teeth 12 are provided on the inner wall of the cavity 11, and the plurality of teeth 12 jointly limit the PCBA board 3 in the cavity 11.

[0043] By such a setting, the PCBA board 3 can be clamped in the cavity 11 by the plurality of teeth 12, so that the PCBA board 3 can be firmly fixed in the cavity 11, is not prone to looseness, and can effectively press the piezoelectric film 2 against the bottom surface of the cavity 11, preventing the piezoelectric film 2 from detaching from the bottom surface of the cavity 11 and affecting the detection accuracy.

[0044] Further, a vibration relief groove 13 is provided at the bottom of the cavity 11, and the vibration relief groove 13 corresponds to a part of the piezoelectric film 2.

[0045] By providing a relief groove, a part of the piezoelectric film 2 can be suspended over the relief groove, while the other part is in contact with the bottom surface of the cavity 11. In this way, the vibration of the housing 1 can be transmitted to the piezoelectric film 2 through the bottom surface of the cavity 11, so that the piezoelectric film 2 generates a piezoelectric signal. At the same time, the piezoelectric film 2 will not be completely compressed and unable to respond to the vibration of the housing 1, thus enabling more accurate detection of the vibration generated by tapping.

[0046] Further, one end of the piezoelectric film 2 is provided with a pin 21. The piezoelectric film 2 is electrically connected to the PCBA board 3 through the pin 21. The pin 21 is bent downward and forms an angle with the PCBA board 3. The PCB board presses the piezoelectric film 2 against the bottom surface of the cavity 11 by applying a force to the pin 21.

[0047] The bottom surface of the PCBA board 3 has pads corresponding to the pins 21. The piezoelectric film 2 is welded to the corresponding pads through the pins 21 to achieve electrical connection and mechanical connection with the PCBA board 3. At this time, the piezoelectric film 2 can not only transmit electrical signals to the PCBA board 3, but also form a certain mechanical connection structure. It should be noted that the pins 21 have a certain bending angle. When the PCBA board 3 is installed in the cavity 11, the pins 21 can support on the bottom surface of the cavity 11, and the PCBA board 3 applies a downward pressure to the pins 21, thereby pressing the piezoelectric film 2 against the bottom surface of the cavity 11 and making the piezoelectric film 2 in contact with the bottom surface of the cavity 11. This can effectively solve the problem that the bottom surface of the PCBA board 3 directly presses the piezoelectric film 2 too tightly or the piezoelectric film 2 cannot be fully in contact with the bottom surface of the cavity 11, which affects the detection accuracy. It can be understood that the piezoelectric film 2 needs to generate a piezoelectric signal through deformation, such as bending, and the piezoelectric film 2 is very sensitive. Due to the certain processing error of the thickness of the PCBA board 3, if the thickness of the PCBA board 3 is too large, the piezoelectric film 2 will be firmly pressed against the bottom surface of the cavity 11, which will cause the piezoelectric film 2 to lose the space for deformation, thus greatly reducing the detection accuracy, or even completely unable to detect the vibration generated by tapping. Similarly, if the PCBA board 3 is too thin, it may cause the piezoelectric film 2 to not be fully in contact with the bottom surface of the cavity 11, and thus it is difficult to respond to the vibration of the housing 1, and the detection sensitivity of the vibration signal will be greatly reduced. Therefore, in the present invention, the pins 21 of the piezoelectric film 2 are bent at a certain angle, and the PCBA board 3 applies a force to the pins 21. By using the elastic force of the pins 21, the piezoelectric film 2 is pressed against the bottom surface of the cavity 11. The pins 21 can absorb the processing error of the PCBA board 3, so as to sensitively and accurately respond to the vibration of the housing 1.

[0048] Further, the PCBA board 3 is provided with a signal transmission module. The PCBA board 3 transmits the detection signal to an external electrical device through the signal transmission module.

[0049] Through the signal transmission module, communication between the PCBA board 3 and external electrical devices can be achieved, thereby transmitting the detection signal to the external electrical devices. The signal transmission module can be any module capable of transmitting signal data, such as a Bluetooth module, an infrared module, an NFC module, a terminal block 32, a zigbee module, or a WIFI module, etc.

[0050] Furthermore, at least one side of the housing 1 has a connecting portion 14, and the housing 1 is fixed to the external electrical device through the connecting portion 14.

[0051] During installation, the connecting portion 14 is mechanically connected to the external electrical device by means of screws, riveting, welding, etc. By setting like this, not only can the knocking sensor be fixed, but also the fixed connection is a hard connection, so that the vibration generated when knocking the electrical device can be effectively transmitted to the housing 1, and then the knocking action on the electrical appliance can be detected more sensitively and accurately.

[0052] Furthermore, the PCBA board 3 is provided with an asymmetric notch 31, and a limiting strip 15 corresponding to the notch 31 one by one is arranged in the cavity 11.

[0053] By setting like this, the effect of preventing misinstallation can be achieved, and the PCBA board 3 can be prevented from being wrongly installed in the cavity 11.

[0054] Furthermore, it further includes potting glue, and the potting glue is used to fix the PCBA board 3 and the piezoelectric film 2 in the cavity 11.

[0055] The potting glue can play a better fixing role to prevent the PCBA board 3 from loosening, and can also play an excellent sealing effect to achieve the effects of dust prevention, moisture prevention, and corrosion prevention.

[0056] Furthermore, the signal transmission module is a terminal block 32.

[0057] Adopting the terminal block 32 can simultaneously achieve the functions of powering the PCBA board 3 and signal transmission.

[0058] Furthermore, the angle between the pin 21 and the PCBA board 3 is 1° to 20°.

[0059] When the foot pins 21 are made of different materials, their elasticity is different, and the corresponding bending angles of the foot pins 21 can be set according to the specific materials. It can be understood that when the angle between the foot pins 21 and the PCBA board 3 is less than 1°, since the angle is too small, it is difficult for the foot pins 21 to press the piezoelectric film 2 against the bottom surface of the cavity 11. When the angle between the foot pins 21 and the PCBA board 3 is greater than 20°, since the bending angle is too large, a large stress will be generated on the solder joints between the foot pins 21 and the PCBA board 3, which is likely to cause de-soldering. Preferably, the angle between the foot pins 21 and the PCBA board 3 is 3° to 10°.

[0060] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the said embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0061] The technical principle of the present invention has been described above in combination with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be construed in any way as a limitation on the protection scope of the present invention. Based on the explanations herein, those skilled in the art can readily conceive of other specific embodiments of the present invention without creative efforts, and these equivalent variations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A knock sensor, characterized in that: include: A housing, wherein a cavity is formed inside the housing; A piezoelectric film, wherein the piezoelectric film is disposed in the cavity; A PCBA board, wherein the PCBA board is confined in the cavity, and the PCBA board presses the piezoelectric film onto the bottom surface of the cavity so that the piezoelectric film is in contact with the bottom surface of the cavity; The piezoelectric film is configured to generate a piezoelectric signal according to the vibration of the housing, the PCBA board is electrically connected to the piezoelectric film, and the PCBA board is configured to process the piezoelectric signal to generate a detection signal and transmit the detection signal.

2. A knock sensor according to claim 1, characterized in that: The inner wall of the cavity is provided with a plurality of latch teeth, and the plurality of latch teeth together restrict the PCBA board in the cavity.

3. A knock sensor according to claim 1, characterized in that: A vibration clearance groove is provided at the bottom of the cavity, and the vibration clearance groove corresponds to a portion of the piezoelectric film.

4. A knock sensor according to claim 1, characterized in that: A pin is provided at one end of the piezoelectric film, and the piezoelectric film is electrically connected to the PCBA board through the pin. The pin is bent downward and forms a certain angle with the PCBA board. The PCB board applies force to the pin to press the piezoelectric film on the bottom surface of the cavity.

5. A knock sensor according to claim 1, characterized in that: The PCBA board is provided with a signal transmission module, and the PCBA board transmits the detection signal to an external electrical device through the signal transmission module.

6. A knock sensor according to claim 1, characterized in that: At least one side of the shell has a connecting portion, and the shell is fixed to an external electrical device through the connecting portion.

7. A knock sensor according to claim 1, characterized in that: The PCBA board is provided with an asymmetric notch, and the cavity is provided with a limiting strip corresponding to the notch one by one.

8. A knock sensor according to claim 1, characterized in that: It also includes a potting glue, and the potting glue is used to fix the PCBA board and the piezoelectric film in the cavity.

9. A knock sensor according to claim 5, characterized in that: The signal transmission module is a wiring terminal.

10. A knock sensor according to claim 4, characterized in that: The angle between the pin and the PCBA board is 1° to 20°.

Images