A piezoelectric vibration sensor

Abstract

The present invention discloses a piezoelectric vibration sensor, including an upper cover plate structure, a positioning plate, a lower cover plate structure, a piezoelectric element and a circuit mechanism. The upper cover plate structure, the positioning plate and the lower cover plate structure are arranged in sequence, and a cavity is formed inside. A channel is arranged on the positioning plate body, one end of the channel is connected to the cavity, and the other end is connected to the environment; one end of the piezoelectric element is arranged in the channel, and the other end is arranged in the cavity. The circuit mechanism is arranged on the positioning plate body and is located in the first cavity. The piezoelectric element leads out an upper electrode and a lower electrode, and is connected to the circuit mechanism. The piezoelectric vibration sensor adopts a stacked structure, and the piezoelectric element is embedded in the cavity of the cover plate, which reduces the space occupancy rate of the product, has a small volume, and expands the scope of use. In addition, the design of the stacked structure can be processed in batches or mass-automated during production, thereby improving production efficiency.

Description

Technical Field

[0001] The present invention relates to the field of sensors, and in particular to a piezoelectric vibration sensor. Background Art

[0002] The vibration sensor is one of the key components in testing technology. Its main function is to receive mechanical quantities and convert them into electrical quantities proportional to them. Since it is also an electromechanical conversion device, we sometimes call it a transducer, a vibration pickup, etc. The vibration sensor takes the original mechanical quantity to be measured as the input quantity of the vibration sensor, which is then received by the mechanical receiving part to form another mechanical quantity suitable for conversion, and finally converted into electrical quantity by the electromechanical conversion part.

[0003] Vibration sensors mainly include piezoelectric accelerometers, piezoresistive accelerometers, variable capacitance accelerometers, etc., among which piezoelectric accelerometers are the most common. Common piezoelectric accelerometers generally include a concave and lifted lower shell, a concave and lifted upper shell, and a mounting mechanism placed between the upper shell and the lower shell. The mounting mechanism is used to fix piezoelectric ceramics and circuit boards. The above structure has low space utilization, large product volume, and inconvenient use. In addition, it needs to be produced and assembled one by one during production, with low automation and low efficiency. Summary of the invention

[0004] The purpose of the present invention is to provide a piezoelectric vibration sensor, which can reduce the volume of the sensor and increase the scope of application.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A piezoelectric vibration sensor includes an upper cover plate structure, a positioning plate, a lower cover plate structure, a piezoelectric element and a circuit mechanism, wherein the positioning plate includes a positioning plate body and a positioning through hole arranged on the positioning plate body, the upper cover plate structure includes an upper cover plate body and a first cavity formed by the upper cover plate body, the lower cover plate structure includes a lower cover plate body and a second cavity formed by the lower cover plate body, the upper cover plate structure, the positioning plate and the lower cover plate structure are arranged in sequence, the first cavity, the positioning through hole and the second cavity are connected to form a cavity, the positioning plate body is also provided with a channel, one end of the channel is connected to the cavity, and the other end is connected to the environment. One end of the piezoelectric element is arranged in the channel, and the other end is arranged in the cavity, the circuit mechanism is arranged on the positioning plate body and is located in the first cavity, the piezoelectric element leads out an upper electrode and a lower electrode, and is connected to the circuit mechanism.

[0007] Preferably, the upper cover plate body includes a first plate body and a second plate body provided with a through hole, the first plate body covers the through hole of the second plate body to form the first cavity. The lower cover plate body includes a third plate body and a fourth plate body provided with a through hole, the third plate body covers the through hole of the fourth plate body to form the second cavity.

[0008] Preferably, the sensor leads out the upper electrode and the lower electrode of the piezoelectric element by setting an upper conductive layer and a lower conductive layer. The upper conductive layer is set on the upper surface of the positioning plate body, one end of which is connected to the upper surface of the piezoelectric element, and the other end is connected to the circuit mechanism. A part of the lower conductive layer is set on the lower surface of the positioning plate body, and the other part passes through the positioning plate body and is set on the upper surface of the positioning plate body. The end of the lower conductive layer located on the lower surface of the positioning plate body is connected to the piezoelectric element, and the end located on the upper surface of the positioning plate body is connected to the circuit mechanism.

[0009] Preferably, the sensor further comprises a mass block, and the mass block is arranged at one end of the piezoelectric element located in the cavity.

[0010] Compared with the prior art, the present invention has the following advantages: it includes an upper cover plate structure, a positioning plate, a lower cover plate structure, a piezoelectric element and a circuit mechanism, the positioning plate includes a positioning plate body and a positioning through hole arranged on the positioning plate body, the upper cover plate structure includes an upper cover plate body and a first cavity formed by the upper cover plate body, the lower cover plate structure includes a lower cover plate body and a second cavity formed by the lower cover plate body, the upper cover plate structure, the positioning plate and the lower cover plate structure are arranged in sequence, the first cavity, the positioning through hole and the second cavity are connected to form a cavity, the positioning plate body is also provided with a channel, one end of the channel is connected to the cavity, and the other end is connected to the environment; one end of the piezoelectric element is arranged in the channel, and the other end is arranged in the cavity, the circuit mechanism is arranged on the positioning plate body and is located in the first cavity, the piezoelectric element leads out an upper electrode and a lower electrode, and is connected to the circuit mechanism. The sensor adopts a stacked structure, and the piezoelectric element is embedded in the cavity of the cover plate, which reduces the product space occupancy rate, is small in size, and expands the scope of use. In addition, the design of the stacked structure can be processed in batches or mass-automated during production, thereby improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings described herein are only for explanation purposes and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only for illustration purposes and are used to help understand the present invention. They do not specifically limit the shapes and proportional dimensions of the components of the present invention. Under the guidance of the present invention, those skilled in the art can select various possible shapes and proportional dimensions to implement the present invention according to specific circumstances. In the drawings:

[0012] Figure 1 is a schematic structural diagram of a piezoelectric vibration sensor according to a first embodiment of the present invention;

[0013] Figure 2 is a schematic diagram of the expansion of the second plate body and the positioning plate of the first embodiment of the present invention;

[0014] Figure 3 is a schematic diagram of the expansion of the third plate body and the positioning plate of the first embodiment of the present invention;

[0015] Figure 4 is a schematic structural diagram of a piezoelectric element according to a first embodiment of the present invention;

[0016] Figure 5 It is a schematic diagram of the structure of a piezoelectric vibration sensor according to the second embodiment of the present invention.

[0017] As shown in the figure: 1-positioning plate, 11-positioning plate body, 12-positioning through hole, 13-channel, 2-piezoelectric element, 21-upper electrode layer, 22-ceramic sheet, 23-conductive layer, 24-lower electrode layer, 3-circuit structure, 41-first plate body, 42-second plate body, 51-third plate body, 52-fourth plate body, 61-upper conductive layer, 62-lower conductive layer, 7-solder or silver glue, 8-mass block. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0019] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0021] Embodiment 1

[0022] See also Figure 1 to Figure 3 A piezoelectric vibration sensor comprises an upper cover structure, a positioning plate 1, a lower cover structure, a piezoelectric element 2 and a circuit mechanism 3, wherein the positioning plate 1 comprises a positioning plate body 11 and a positioning through hole 12 arranged on the positioning plate body 11, the upper cover structure comprises an upper cover body and a first cavity formed by the upper cover body, the lower cover structure comprises a lower cover body and a second cavity formed by the lower cover body, the upper cover structure, the positioning plate 1 and the lower cover structure are arranged in sequence, the first cavity, the positioning through hole 12 and the second cavity are connected to form a cavity, and a channel 13 is also provided on the positioning plate body 11, one end of the channel 13 is connected to the cavity, and the other end is connected to the environment. One end of the piezoelectric element 2 is arranged in the channel 13, and the other end is arranged in the cavity. The circuit mechanism 3 is arranged on the positioning plate body 11 and is located in the first cavity. The piezoelectric element 2 leads out an upper electrode and a lower electrode and is connected to the circuit mechanism 3, and three electrodes are led out from the circuit mechanism 3 to connect to a processor located in the environment. The circuit mechanism 3 is a circuit board, and a signal processing circuit is printed on the circuit board.

[0023] In order to facilitate production, the upper cover plate body is designed as a block structure. The upper cover plate body includes a first plate body 41 and a second plate body 42 with a through hole. The first plate body 41 covers the through hole of the second plate body 42 to form the first chamber. The process of producing through holes is simpler than the process of producing chambers. The first plate body 41 covers the second plate body 42, and the first plate body 41 plays a protective role. Similarly, the lower cover plate body includes a third plate body 51 and a fourth plate body 52 with a through hole. The third plate body 51 covers the through hole of the fourth plate body 52 to form the second chamber. The first plate body 41, the second plate body 42, the positioning plate 1, the third plate body 51 and the fourth plate body 52 are fixed by adhesive.

[0024] The sensor leads out the upper electrode and the lower electrode of the piezoelectric element 2 by setting an upper conductive layer 61 and a lower conductive layer 62. One end of the piezoelectric element 2 is set in the channel 13 and fixed in position, which is a fixed end, and the other end is set in the cavity, which is a movable end. One end of the upper conductive layer 61 is connected to the fixed end of the piezoelectric element 2, and the other end is connected to the circuit mechanism 3. One end of the lower conductive layer 62 is connected to the fixed end of the piezoelectric element 2, and the other end is connected to the circuit mechanism 3, thereby leading out the upper electrode and the lower electrode. The upper conductive layer 61 and the lower conductive layer 62 are both fixed on the positioning plate body 11, and the piezoelectric element 2 and the circuit mechanism 3 are respectively connected by setting solder or silver glue at the connection. Further, the upper conductive layer 61 is set on the upper surface of the positioning plate body 11, one end is connected to the upper surface of the piezoelectric element 2, and the other end is connected to the circuit mechanism 3, and solder or silver glue 7 is set at the connection. A portion of the lower conductive layer 62 is disposed on the lower surface of the positioning plate body 11, and the other portion passes through the positioning plate body 11 and is disposed on the upper surface of the positioning plate body 11. One end of the lower conductive layer 62 located on the lower surface of the positioning plate body 11 is connected to the piezoelectric element 2, and the other end located on the upper surface of the positioning plate body 11 is connected to the circuit mechanism 3, and solder or silver glue 7 is disposed at the connection points.

[0025] See also Figure 4 The piezoelectric element 2 includes an upper electrode layer 21, at least two ceramic sheets 22, a conductive layer 23 arranged between adjacent ceramic sheets 22, and a lower electrode layer 24, which are arranged in sequence. In this embodiment, the piezoelectric element 2 includes an upper electrode layer 21, a first ceramic sheet 22, a conductive layer 23, a second ceramic sheet 22 and a lower electrode layer 24, which are arranged in sequence, and the conductive layer 23 is made of copper foil.

[0026] The sensor is subjected to continuous vibration force, and the piezoelectric element 2 generates an electrical signal to convert mechanical energy into electrical energy. The electrical signal is transmitted to the circuit structure 3 through the upper conductive layer 61 and the lower conductive layer 62. The circuit structure 3 leads to three electrodes and is connected to a processor in the environment.

[0027] Embodiment 2

[0028] The difference between the second embodiment and the first embodiment is that the sensor further comprises one or two mass blocks 8, and the mass blocks 8 are arranged at the active end of the piezoelectric element 2. When the sensor is provided with one mass block 8, the mass block 8 can be arranged on the upper surface or the lower surface of the active end of the piezoelectric element 2, such as Figure 5 As shown, the mass block 8 is arranged on the upper surface of the active end of the piezoelectric element 2. When the sensor is provided with two mass blocks 8, one mass block 8 is arranged on the upper surface of the piezoelectric element 2, and the other mass block 8 is arranged on the lower surface of the piezoelectric element 2. The mass block 8 is arranged to improve the sensitivity of the sensor.

[0029] The above sensors are all plate-shaped stacked structures. When producing the first plate body 41, the second plate body 42, the third plate body 51, the fourth plate body 52 and the positioning plate 1, they can be stacked for shearing, batch processing, or large-scale automated production, thereby improving production efficiency.

[0030] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the foregoing claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A piezoelectric vibration sensor, It is characterized in that It includes an upper cover plate structure, a positioning plate, a lower cover plate structure, a piezoelectric element and a circuit mechanism, the positioning plate includes a positioning plate body and a positioning through hole arranged on the positioning plate body, the upper cover plate structure includes an upper cover plate body and a first cavity formed by the upper cover plate body, the lower cover plate structure includes a lower cover plate body and a second cavity formed by the lower cover plate body, the upper cover plate structure, the positioning plate and the lower cover plate structure are arranged in sequence, the first cavity, the positioning through hole and the second cavity are connected to form a cavity, the positioning plate body is also provided with a channel, one end of the channel is connected to the cavity, and the other end is connected to the environment; one end of the piezoelectric element is arranged in the channel, and the other end is arranged in the cavity, the circuit mechanism is arranged on the positioning plate body and is located in the first cavity, the piezoelectric element leads out an upper electrode and a lower electrode, and is connected to the circuit mechanism; The upper cover plate body comprises a first plate body and a second plate body provided with a through hole, wherein the first plate body covers the through hole of the second plate body to form the first chamber; The lower cover plate body includes a third plate body and a fourth plate body provided with a through hole, and the third plate body covers the through hole of the fourth plate body to form the second chamber; The sensor leads out the upper electrode and the lower electrode of the piezoelectric element by setting an upper conductive layer and a lower conductive layer, one end of the upper conductive layer is connected to the piezoelectric element, and the other end is connected to the circuit mechanism, and one end of the lower conductive layer is connected to the piezoelectric element, and the other end is connected to the circuit mechanism; The upper conductive layer and the lower conductive layer are both fixed on the positioning plate body; The upper conductive layer is arranged on the upper surface of the positioning plate body, one end of which is connected to the upper surface of the piezoelectric element, and the other end of which is connected to the circuit mechanism; A portion of the lower conductive layer is disposed on the lower surface of the positioning plate body, and the other portion passes through the positioning plate body and is disposed on the upper surface of the positioning plate body. One end of the lower conductive layer located on the lower surface of the positioning plate body is connected to the piezoelectric element, and the other end located on the upper surface of the positioning plate body is connected to the circuit mechanism.

2. The sensor according to claim 1, It is characterized in that The piezoelectric element comprises an upper electrode layer, at least two ceramic sheets, a conducting layer arranged between adjacent ceramic sheets, and a lower electrode layer which are arranged in sequence.

3. The sensor according to claim 1, It is characterized in that The sensor further comprises a mass block, and the mass block is arranged at one end of the piezoelectric element located in the cavity, and one or two mass blocks are arranged.

4. The sensor according to claim 3, It is characterized in that When the sensor is provided with one mass block, the mass block is provided on the upper surface or the lower surface of the piezoelectric element; when the sensor is provided with two mass blocks, one mass block is provided on the upper surface of the piezoelectric element, and the other mass block is provided on the lower surface of the piezoelectric element.

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