Accelerometer

Abstract

This utility model discloses an accelerometer, comprising: a housing with an opening; a core support fixed within the housing, the core support having three mounting slots, each mounting slot being independently arranged by the core support and the inner wall of the housing; three sets of core components, each set being orthogonal to the others, corresponding one-to-one with the three mounting slots, each core component being disposed within its corresponding mounting slot and mounted on the core support; and a circuit board disposed within the housing, electrically connected to each of the core components. Through a highly integrated and unified support design concept, high-performance and high-reliability triaxial measurement is achieved.

Description

Technical Field

[0001] This invention belongs to the field of piezoelectric accelerometer technology, and specifically relates to an accelerometer. Background Technology

[0002] Accelerometers are widely used in industrial vibration monitoring, structural health diagnosis, vehicle testing, aerospace and other fields. Traditional piezoelectric accelerometers mostly use a shell frame as the mounting base and assemble the core components from the outside in. This method has problems such as high assembly difficulty, loose structure, and insufficient overall rigidity, which leads to a limited frequency response range of the sensor. Low frequencies are usually only up to 2Hz, and high frequencies are also prone to signal distortion due to structural resonance.

[0003] Therefore, there is a lack of a highly reliable accelerometer structure in the existing technology that can both guarantee measurement accuracy and have excellent frequency characteristics. Utility Model Content

[0004] This utility model provides a novel acceleration sensor, comprising: A housing having an opening; A core support is fixed inside the housing, and the core support has three mounting slots, and the core support and the inner wall of the housing form each mounting slot, and each mounting slot is independently arranged. Three sets of core components, the three sets of core components are orthogonal to each other, the three sets of core components correspond one-to-one with the three mounting slots, and each core component is set in the corresponding mounting slot; A circuit board is disposed within the housing and is electrically connected to each of the core components.

[0005] In one possible implementation, the housing includes a first cavity and a second cavity, and the opening communicates with the second cavity; The core support and each of the core components are disposed in the first cavity; the circuit board is disposed in the second cavity.

[0006] In one possible implementation, the circuit board is connected to an external wire that passes through the opening into the housing and connects to the circuit board.

[0007] In one possible implementation, the space within the housing is divided into a first cavity and a second cavity along an axis perpendicular to the opening.

[0008] In one possible implementation, each of the core components is electrically connected to the side surface of the circuit board opposite to the first cavity via wires.

[0009] In one possible implementation, one of the mounting slots is provided on the surface of the core support facing the second cavity; With the direction from the first cavity to the second cavity as the axis, two additional mounting slots are provided on the outer ring surface of the core support.

[0010] In one possible implementation, the other two mounting slots are both oriented away from the opening.

[0011] In one possible implementation, external wires enter the second cavity through the opening and are electrically connected to each of the circuit boards.

[0012] In one possible implementation, the core assembly includes: A core support column is provided perpendicularly to the core support and is located on the core support. A piezoelectric ceramic ring, wherein the piezoelectric ceramic ring is sleeved outside the core support; A mass ring, wherein the mass ring is sleeved outside the piezoelectric ceramic ring; The mass ring is electrically connected to the circuit board, and the piezoelectric ceramic ring is electrically connected to the mass ring.

[0013] In one possible implementation, the housing is a cube or a cuboid. Attached Figure Description

[0014] Main component labeling instructions: In some sensors: 1', Housing; 11', Opening; 2', Core assembly; 3', Microcircuit; 4', Hoop ring; In the embodiments of this application: 1. Housing; 11. First cavity (lower cavity); 12. Second cavity (upper cavity); 13. Opening; 2. Core assembly; 21. Core support; 22. Piezoelectric ceramic ring; 23. Mass ring; 3. Core support; 31. Mounting slot; 4. Circuit board; 5. Wire; Figure 1a This is a schematic diagram of an acceleration sensor. Figure 1b This is a schematic diagram of the accelerometer sensor after the top cover is removed from the housing in an embodiment of this application; Figure 2 This is a schematic diagram of the accelerometer sensor structure after removing the top cover and circuit board from the housing in the embodiment of this application; Figure 3 This is a schematic diagram of the accelerometer structure after removing the top cover, circuit board, piezoelectric ceramic ring and mass ring from the housing in the embodiment of this application. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this utility model clearer, the various embodiments of this utility model will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this utility model to facilitate a better understanding of this application. However, the technical solutions claimed in the claims of this application can be implemented even without these technical details and with various variations and modifications based on the following embodiments.

[0016] Unless the context requires otherwise, throughout the specification and claims, the word “comprising” and its variations, such as “including” and “having”, shall be understood to have an open, inclusive meaning, that is, to be interpreted as “including, but not limited to”.

[0017] The embodiments of this utility model will be described in detail below with reference to the accompanying drawings to provide a clearer understanding of the purpose, features, and advantages of this utility model. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of this utility model, but are merely illustrative of the essential spirit of the technical solution of this utility model.

[0018] Throughout this specification, references to "an embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Therefore, the appearance of "in an embodiment" or "an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any manner in one or more embodiments.

[0019] The singular forms “a” and “the” used in this specification and the appended claims include plural references unless otherwise expressly stated herein. It should be noted that the term “or” is generally used to mean “and / or” unless otherwise expressly stated herein.

[0020] In the following description, in order to clearly demonstrate the structure and working method of this utility model, a number of directional terms will be used. However, terms such as "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and not as limiting terms.

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but this should not be construed as limiting the scope of the present invention.

[0022] In some sensors, such as Figure 1aAs shown, the accelerometer mainly includes a housing 1', three core components 2', and three microcircuits 3'. The housing 1' has an opening 11', and the three core components 2' and three microcircuits 3' are all located inside the housing 1'. The core components 2' are used to sense external acceleration signals, and each core component 2' is provided with a clamp 4', which is used to fix the core component 2'.

[0023] The three core components 2' correspond one-to-one with the three microcircuits 3'. Each core component 2' is electrically connected to its corresponding microcircuit 3', and each microcircuit 3' is used for preliminary processing and output of the sensing signal. The housing 1' encapsulates and protects the internal components. All three core components 2' are suspended in the air and rely mainly on surrounding fixing components to maintain their position, thereby completing the sensing and output of the acceleration signal.

[0024] The core weakness of this design lies in the lack of a unified and robust mechanical reference for its core components 2'. Each core component 2' relies solely on its connection to the local housing 1' for support, resulting in a so-called "suspended" state. This structure has low overall mechanical stiffness, and when subjected to high-frequency vibration excitation, not only are the core components 2' themselves prone to unnecessary resonance, but their supporting structure also undergoes slight deformation, leading to a low overall resonant frequency for the sensor. Its effective measurement frequency limit is typically difficult to exceed 5000Hz; beyond this, some measurement signals will be distorted, making it impossible to accurately acquire high-frequency vibration information.

[0025] To barely increase its natural frequency, some solutions employ a "weight reduction" strategy, namely reducing the mass of the mass block in the core assembly 2'. According to physics, the voltage sensitivity of the sensor is proportional to the mass of the mass block. Reducing the mass directly leads to a dilemma: while the theoretical resonant frequency is slightly increased, the charge / voltage output signal strength is drastically weakened, significantly deteriorating the signal-to-noise ratio (SNR) in the low-frequency measurement range. Weak low-frequency vibration signals are submerged in background noise, resulting in poor low-frequency measurement performance and a narrower dynamic range.

[0026] In addition, the three independent circuit boards and their connection points to their respective cores are all exposed in the same large cavity. Once the high humidity environment moisture enters the cavity, the moisture will corrode the piezoelectric ceramic elements and their electrodes of each core component 2', causing their piezoelectric performance to degrade, and ultimately causing permanent drift or complete failure of the sensor sensitivity.

[0027] Therefore, this application also provides an acceleration sensor, such as... Figures 1b to 3 As shown, the accelerometer includes a housing 1, a core support 3, three core assemblies 2, and a circuit board 4.

[0028] An opening 13 is provided on the housing 1. The core support 3 is fixedly installed inside the housing 1. The core support 3 has three mounting slots 31, and each mounting slot 31 is formed by the corresponding surface of the core support 3 and the inner wall of the housing 1, so that the three mounting slots 31 are set independently of each other.

[0029] The three core components 2 are arranged in pairs orthogonal space. Each core component 2 corresponds to a mounting slot 31 and is installed and fixed in its respective mounting slot 31, while maintaining a rigid connection with the core support 3.

[0030] The circuit board 4 is located inside the housing 1 and is electrically connected to each core assembly 2 via wires 5.

[0031] Compared to Figure 1a The solution described in this application, through a highly integrated and unified support design concept, achieves high-performance and high-reliability triaxial measurement. First, the solution in this application embodiment provides integrated support with high rigidity, enabling wideband measurement (especially with outstanding high-frequency advantages). Specifically, one of the core innovations of this solution lies in placing all three core components 2 on a unified core support 3. This core support 3, as a robust, integrated mechanical reference, provides extremely stable and rigid support for the core in all three directions. This structure greatly improves the overall mechanical rigidity of the sensor, thereby pushing its inherent resonant frequency to a very high level. Therefore, this sensor can significantly extend the high-frequency end of the effective measurement frequency range to 10000Hz or even higher without sacrificing signal quality, and within this range, it has good amplitude linearity and phase response, enabling accurate capture of high-frequency vibration phenomena.

[0032] Secondly, the solution in this application exhibits excellent low-frequency response and signal-to-noise ratio. Thanks to its high-rigidity design, this solution does not require sacrificing performance by reducing weight to achieve high-frequency characteristics. Instead, we can use a sufficiently large inertial mass block to ensure that the piezoelectric element is subjected to sufficient mechanical force, generating a strong charge signal. This allows the sensor to maintain extremely high voltage sensitivity and excellent signal-to-noise ratio even at low frequencies (down to 0.5Hz), enabling clear and stable measurement of very weak low-frequency vibrations, achieving wideband, high-fidelity measurement from extremely low to extremely high frequencies.

[0033] Meanwhile, due to the independent spatial layout of the three mounting slots 31, even if external water vapor enters the interior of the housing 1 through the opening 13 of the housing 1, it is difficult for it to be transmitted between the three mounting slots 31, thereby effectively blocking water vapor from contacting and corroding the core component 2, and improving the environmental adaptability and long-term reliability of the sensor.

[0034] Finally, all core components 2 are mounted on the same core support 3, simplifying the assembly process. Only one precise positioning is required to complete the installation of all cores, significantly improving production efficiency and product consistency. The uniform rigid structure also means that the sensor has higher mechanical stability and a longer service life in harsh vibration environments.

[0035] In another possible embodiment, the housing 1 adopts a cuboid or cube structure, with its interior divided into an upper first cavity 11 and a lower second cavity 12 along an axis perpendicular to the opening 13. The opening 13 is located on the housing 1 and communicates with the second cavity 11. This layout allows the sensor to form two independent spaces, with the upper part being the circuit board cavity, i.e., the second cavity 12, and the lower part being the core cavity, i.e., the first cavity 11. The two are structurally completely isolated and are electrically connected only through wires 5.

[0036] The technical solution claimed in this application achieves multiple technical effects through the "shell 1-cavity-component" layout, which together constitute the core progress of the present invention compared with the prior art. Its core lies in the concept of completely separating the upper and lower cavities, that is, the first cavity 11 (lower part) is specially used to accommodate three sets of orthogonal core components 2, while the second cavity 12 (upper part) is specially used to install the circuit board 4.

[0037] Firstly, in terms of structural layout and space optimization, this scheme achieves physical isolation of functional modules through a strict upper and lower cavity design. The core, as a sensitive mechanical-to-electrical signal conversion unit, is centrally located in the lower first cavity 11, forming a pure mechanical environment. Meanwhile, the circuit board 4, as an electronic signal processing unit, is independently packaged in the upper second cavity 12, forming a controlled electromagnetic environment. This layout not only maximizes the utilization efficiency of internal space, achieving a highly compact and miniaturized overall sensor structure, but more importantly, it physically eliminates the potential mechanical interference and electromagnetic crosstalk that might occur when the circuit board 4 and the core share a cavity in traditional designs, laying a solid foundation for high-precision sensor measurements.

[0038] Secondly, the solution is particularly effective in improving performance and signal quality. The three core components 2 are precisely arranged in pairs orthogonal configurations within the lower first cavity 11, and are stably supported by a unified core support 3. This ensures extremely high precision and long-term stability in the spatial geometry of the three sensitive axes. Simultaneously, because the core components 2 are located far from subsequent electrical signal processing circuits, interference from high-frequency digital signals or power supply noise in the circuit board 4 to the weak analog charge signal is effectively avoided through spatial coupling.

[0039] Third, this solution improves system reliability through optimized electrical interconnection paths. Circuit board 4 is located in the second cavity 12, and the weak charge signal generated by the core assembly 2 is transmitted upwards to circuit board 4 via wire 55. External wire 5 enters the second cavity 12 through opening 13 and connects directly to circuit board 4, avoiding direct transmission of external tensile stress to the sensitive core assembly 2 and enhancing the mechanical performance of the interface.

[0040] Finally, from a manufacturability and reliability perspective, the modular design with upper and lower cavities simplifies the assembly process into two distinct stages: first, all core components 2 are precisely installed and adjusted in the lower cavity; then, the circuit board 4 is independently fixed and soldered in the upper cavity. This "mechanical first, electrical later" assembly logic greatly simplifies operation and improves production efficiency and quality consistency. Simultaneously, the structural independence of the two cavities means that a failure or damage to one module will not easily affect the other. For example, overheating of components on circuit board 4 will not directly affect the temperature field of the core, thereby improving the overall reliability of the product.

[0041] In summary, the technical solution of this application embodiment, through the core layout of "arranging the core in the lower cavity and arranging the circuit board 4 in the upper cavity", brings about a huge technological advancement in multiple dimensions such as sensor miniaturization, measurement accuracy, signal integrity, production yield and long-term reliability.

[0042] Of course, it should be noted that, in addition to being arranged vertically, the first cavity 11 and the second cavity 12 are also arranged vertically, that is, along... Figure 1b Besides the Z-direction, the arrangement can also be along the left and right or front and back. In short, the arrangement between the first cavity 11 and the second cavity 12 can be varied. For example, it can also be along the axis perpendicular to the opening 13. The axis direction is... Figure 1b In the Y direction, the space inside the housing 1 is divided into a first cavity 11 and a second cavity 12. Of course, in some embodiments, the circuit board and the three sets of core components can also be arranged in the same cavity.

[0043] In another possible implementation, the core support is preferably made of hard aluminum alloy or iron alloy by precision milling, which has high rigidity and good stability. Figure 3 This is a schematic diagram of the accelerometer structure after removing the top cover, circuit board, piezoelectric ceramic ring, and mass ring from the housing in this embodiment of the application. Figure 3As shown, the core support 3 has three mounting slots 31 machined on it. One slot is located on the top surface of the core support 3 (i.e., the side facing the second cavity 12), and the other two are located on the outer circumferential surface of the support. The slots are all oriented to the side, preferably away from the opening 13. This means that the mounting slots 31 are not opposite to the opening 13, avoiding interference with the threading of external wires. This arrangement ensures that the three sets of core components 2 are spatially orthogonal to each other, i.e., respectively along... Figure 1b The X, Y, and Z directions are set up for measurement. Figure 1b Acceleration in the X, Y, and Z directions.

[0044] Each core assembly 2 includes a core support 21, a piezoelectric ceramic ring 22, and a mass ring 23. The core support 21, made of stainless steel or other ferroalloy, is perpendicular to the core support direction, fixed in the mounting groove 31, and fixedly connected to the core support. The piezoelectric ceramic ring 22 is sleeved on the outside of the core support 21, with its polarization direction along the axial direction. The mass ring 23 is sleeved on the outside of the piezoelectric ceramic ring 22 and is fixed by conductive adhesive to achieve electrical connection. When the sensor is subjected to vibration acceleration, the mass ring 23 applies pressure to the piezoelectric ceramic ring 22 due to inertia, generating an electric charge signal, which is then discharged through the mass ring 23.

[0045] The circuit board 4 is fixed inside the second cavity 12, and its upper surface (i.e., the surface facing away from the first cavity 11) is connected to each mass ring 23 via wires 5. The wires 5 are flexible conductors that pass through pre-set small holes on the core support 3 to avoid connection failure due to mechanical stress in a vibrating environment. The external signal cable is introduced through the opening 13, connected to the second cavity 12, and soldered to the circuit board 4 to complete the signal output.

[0046] In this structure, the core and circuit board are arranged in separate cavities, and the core support serves as the overall base supporting three orthogonal cores, significantly improving the overall rigidity of the sensor. The sensor's frequency response range is significantly broadened, with low frequencies reduced to 0.5Hz and high frequencies extended due to the increased structural resonant frequency. Furthermore, the assembly process is simplified and reliable due to the modular structure, making it suitable for mass production.

[0047] In another embodiment, the housing 1 can also adopt a cubic structure to further optimize space utilization. The mounting groove 31 of the core support 3 can also adopt other arrangement angles, as long as the three sets of core components 2 are orthogonal. The piezoelectric ceramic ring 22 can also be replaced with other piezoelectric materials, such as PVDF polymer piezoelectric film, to adapt to different measurement scenarios.

[0048] In summary, this invention effectively solves the problems of complex assembly, insufficient rigidity, and narrow frequency response of traditional sensors through the design of upper and lower cavities, orthogonal arrangement of the core, and centralized arrangement of the circuit board, and realizes an acceleration sensor structure with high reliability, wide frequency response, and easy assembly.

[0049] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the present invention.

Claims

1. An acceleration sensor, characterized in that, include: A housing having an opening; A core support is fixed inside the housing, and the core support has three mounting slots, and the core support and the inner wall of the housing form each mounting slot, and each mounting slot is independently arranged. Three sets of core components, the three sets of core components are orthogonal to each other, the three sets of core components correspond one-to-one with the three mounting slots, each core component is set in the corresponding mounting slot and is set on the core support; A circuit board is disposed within the housing and is electrically connected to each of the core components.

2. The acceleration sensor according to claim 1, characterized in that, The housing includes a first cavity and a second cavity, and the opening communicates with the second cavity; The core support and each of the core components are disposed in the first cavity; the circuit board is disposed in the second cavity.

3. The accelerometer according to claim 1, characterized in that, The circuit board is connected to an external wire, which passes through the opening into the housing and connects to the circuit board.

4. The acceleration sensor according to claim 2, characterized in that, Along the axis perpendicular to the opening, the space inside the housing is divided into the first cavity and the second cavity.

5. The accelerometer according to claim 4, characterized in that, Each of the core components is electrically connected to the side of the circuit board opposite to the first cavity via wires.

6. The acceleration sensor according to claim 5, characterized in that, One of the mounting slots is provided on the surface of the core support facing the second cavity; With the direction from the first cavity to the second cavity as the axis, two additional mounting slots are provided on the outer ring surface of the core support.

7. The accelerometer according to claim 6, characterized in that, The other two mounting slots are both oriented away from the opening.

8. The accelerometer according to claim 1, characterized in that, External wires enter the second cavity through the opening and are electrically connected to each of the circuit boards.

9. The accelerometer according to claim 4, characterized in that, The core assembly includes: A core support column is provided perpendicularly to the core support and is located on the core support. A piezoelectric ceramic ring, wherein the piezoelectric ceramic ring is sleeved outside the core support; A mass ring, wherein the mass ring is sleeved outside the piezoelectric ceramic ring; The mass ring is electrically connected to the circuit board, and the piezoelectric ceramic ring is electrically connected to the mass ring.

10. The accelerometer according to claim 1, characterized in that, The shell is a cube or a cuboid.

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