Flat three-dimensional acceleration and three-dimensional force composite sensor and detection method thereof

Abstract

The invention relates to a flattened three-dimensional acceleration and three-dimensional force composite sensor and a detection method thereof, and belongs to the field of sensors. According to the technical scheme, the flattened three-dimensional acceleration and three-dimensional force composite sensor comprises a force sensor module and an acceleration sensor module, the force sensor module comprises four shear effect force detection elements and four longitudinal effect force detection elements, and the four shear effect force detection elements and the four longitudinal effect force detection elements are coplanar. The acceleration sensor module comprises four shear effect acceleration detection elements and four longitudinal effect acceleration detection elements, and the four shear effect acceleration detection elements and the four longitudinal effect acceleration detection elements are coplanar. According to the scheme, the sensitive elements with the longitudinal effect and the shear effect are combined, three-dimensional detection is achieved through the thickness of the single-layer sensitive element, flattening of the sensor is achieved through single-layer arrangement of the sensitive elements, thermal expansion and stress are greatly reduced in the installation direction, and the detection precision is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of sensors, and in particular to a flattened three-dimensional acceleration and three-dimensional force composite sensor and its detection method. Background Technology

[0002] Acceleration and pressure sensors use piezoelectric materials as sensing elements to measure acceleration and pressure physical quantities under external force. They are typically composed of core components such as a housing and sensing element, and are widely used in many fields such as industrial monitoring and aerospace. Among them, three-dimensional force sensors can simultaneously measure force values ​​in the X, Y, and Z directions, and are suitable for the detection needs of complex motion.

[0003] However, whether it is a piezoelectric effect three-dimensional sensor or a shear effect three-dimensional sensor, three-dimensional detection requires the combination of sensitive elements in three directions, so the overall size is large. Moreover, if the combined detection of acceleration and force is to be achieved, a composite sensor or two types of sensors need to be used together, which further increases the size of the sensor.

[0004] In the field of nuclear lead-bismuth (such as lead-bismuth fast reactors and accelerator-driven subcritical systems), accelerometers and force composite sensors operate in high-temperature, high-pressure, strong-radiation, and corrosive environments using liquid lead-bismuth alloy as a coolant. These sensors also require extremely high accuracy. The large thickness of traditional three-dimensional composite sensors can pose challenges to installation and layout. Besides the space requirement, the large volume can also lead to insufficient stability of the composite sensor in extreme environments. Specifically, high-temperature and high-pressure environments cause thermal expansion and stress in the sensor materials. The large thickness of traditional three-dimensional composite sensors means that the internal structural stress generated in such environments is even greater, easily leading to structural damage or performance degradation. Summary of the Invention

[0005] This invention addresses the problem that current three-dimensional acceleration and force composite sensors are bulky and difficult to apply to extreme environments by providing a flat three-dimensional acceleration and force composite sensor.

[0006] To solve the above problems, the technical solution adopted by the present invention is a flattened three-dimensional acceleration and three-dimensional force composite sensor, including a housing. A force sensor module and an acceleration sensor module are disposed inside the housing. The housing has a central axis. The force sensor module includes four shear force detection elements and four longitudinal force detection elements. The four shear force detection elements and the four longitudinal force detection elements are coplanar, and this plane is perpendicular to the central axis. The four shear force detection elements are evenly arranged around the central axis, and the four longitudinal force detection elements are coplanar and evenly arranged around the central axis. An outer insulating ring for the force sensor is provided between the shear force detection elements and the longitudinal force detection elements. The component and the longitudinal effect force detection element are provided with force sensor pre-compression structures on their upper and lower sides. The acceleration sensor module includes four shear effect acceleration detection elements and four longitudinal effect acceleration detection elements. The four shear effect acceleration detection elements and the four longitudinal effect acceleration detection elements are coplanar, and this plane is perpendicular to the central axis. The four shear effect acceleration detection elements are evenly arranged around the central axis, and the four longitudinal effect acceleration detection elements are coplanar and evenly arranged around the central axis. An outer insulating ring for the acceleration sensor is provided between the shear effect acceleration detection elements and the longitudinal effect acceleration detection elements. Acceleration sensor pre-compression structures are provided on the upper and lower sides of the shear effect acceleration detection elements and the longitudinal effect acceleration detection elements. This solution ingeniously combines two types of sensitive elements, namely longitudinal effect and shear effect, and integrates three-dimensional detection with the same function into a planar layer. Three-dimensional detection is achieved with the thickness of a single-layer sensitive element, which greatly reduces the thickness of the three-dimensional composite sensor and can be installed in narrower spaces. At the same time, the single-layer arrangement of the sensitive elements realizes the flattening of the sensor shell, which greatly reduces thermal expansion and stress in the installation direction and ensures detection accuracy.

[0007] As a preferred implementation of a flattened three-dimensional acceleration and force composite sensor, the shear effect force detection element, the longitudinal effect force detection element, the shear effect acceleration detection element, and the longitudinal effect acceleration detection element are all coplanarly arranged, sequentially along a direction away from the central axis. An inner insulating ring for the force sensor is provided between the shear effect acceleration detection element and the longitudinal effect force detection element. By placing the acceleration detection element and the force detection element on the same layer, the internal planar space of the housing is fully utilized, further reducing the overall thickness of the composite sensor. The inner insulating ring for the force sensor enables precise partitioning and fixation of the two sets of detection elements, avoiding mutual interference during signal transmission and further improving the accuracy of the detection data. Simultaneously, it simplifies the internal structure of the composite sensor, facilitates assembly, and reduces manufacturing costs.

[0008] As a preferred implementation of a flattened three-dimensional acceleration and three-dimensional force composite sensor, the housing includes a top cover and a base. A quartz glass plate is provided on the upper surface of the base. The shear force detection element, the longitudinal force detection element, the shear acceleration detection element, and the longitudinal acceleration detection element are all placed on the quartz glass plate. The top cover and the base are fixedly connected, with the top cover pressing against the shear force detection element and the longitudinal force detection element to form the force sensor pre-compression structure. The pre-compression force is directly generated using the assembly clamping force of the top cover, eliminating the need for additional complex pre-compression components. This simplifies the internal structure of the sensor, further reducing the axial thickness and lowering the accuracy requirements during component assembly, thus improving production efficiency. Furthermore, this pre-compression method ensures that the force detection element remains in a stable stress state, guaranteeing the consistency of the force detection data. The quartz glass plate has excellent insulation and stability, providing a flat and stable mounting surface for the detection elements.

[0009] As a preferred implementation of a flattened three-dimensional acceleration and three-dimensional force composite sensor, a central column is provided at the center of the upper surface of the base. The shear effect acceleration detection element and the longitudinal effect acceleration detection element are arranged around the central column. An inner insulating ring of the acceleration sensor is provided between the longitudinal effect force detection element and the central column. The acceleration sensor pre-compression structure includes a mass block, which is sleeved on the outside of the inner insulating ring of the acceleration sensor. The upper end of the central column is provided with an external thread, and a tightening nut is threaded onto the external thread. The tightening nut is pressed against the top of the mass block, and the bottom surface of the mass block is pressed against the top of the shear effect acceleration detection element and the longitudinal effect acceleration detection element. A receiving cavity is provided at the center of the bottom surface of the upper cover, and the central column, the mass block, and the tightening nut are all located in the receiving cavity. The acceleration sensor preload structure is formed by the cooperation of the central column, mass block, and tightening nut. The threaded connection of the tightening nut allows for flexible and precise setting of the preload, preventing preload rebound and improving the sensor's adaptability and accuracy to different acceleration ranges. At the same time, the upper cover cavity encloses the central column, mass block, and other components. The cavity design allows for a more compact internal component layout without increasing the housing volume, maintaining a flat structure. In addition, the central column can also position the detection elements arranged around it, ensuring the coaxiality of the element installation and reducing detection errors caused by eccentricity.

[0010] As a preferred implementation of a flattened three-dimensional acceleration and three-dimensional force composite sensor, the length of the external thread is greater than the thickness of the tightening nut. A threaded hole is provided at the center of the top surface of the receiving cavity, and the threaded hole is threadedly connected to the external thread. A wrench-shaped surface is also provided on the outer periphery of the top cover. This threaded connection structure not only further enhances the connection stability between the top cover and the base, preventing springback after pre-tightening, but also allows for secondary adjustment or stabilization of the internal pre-pressure through rotating the top cover, enabling precise calibration of the pre-pressure and improving detection accuracy. The wrench-shaped surface on the outer periphery of the top cover provides convenience for gripping and rotating during installation, preventing slippage and improving assembly efficiency. It also facilitates subsequent disassembly and maintenance of the sensor.

[0011] As a preferred implementation of a flattened three-dimensional acceleration and three-dimensional force composite sensor, the shear effect force detection element and the longitudinal effect force detection element are lithium niobate crystal sheets; the shear effect acceleration detection element and the longitudinal effect acceleration detection element are piezoelectric ceramic sheets. The force detection element uses a lithium niobate crystal sheet, which has excellent piezoelectric properties and mechanical stability, maintaining a stable signal output even under large external forces, thus improving the range and accuracy of force detection. The acceleration detection element uses a piezoelectric ceramic sheet, which has a high piezoelectric coefficient and fast response speed, enabling rapid capture of instantaneous acceleration changes and improving the sensitivity of acceleration detection. Both materials have small volume and thickness, without compromising the flattened structure of the sensor, and are relatively inexpensive, balancing performance and economy, making them suitable for large-scale production applications.

[0012] As a preferred implementation of a flattened three-dimensional acceleration and three-dimensional force composite sensor, the housing further includes an outer sleeve. The upper cover and the base are located within the outer sleeve, and the outer peripheral surfaces of the upper cover and the base are fitted to the inner peripheral surface of the outer sleeve. An upper positioning step is provided on the top edge of the outer peripheral surface of the upper cover, and this upper positioning step is fitted to and welded to the upper edge of the outer sleeve. A lower positioning step is provided on the bottom edge of the outer peripheral surface of the base, and this lower positioning step is fitted to and welded to the lower edge of the outer sleeve. Adding an outer sleeve and welding the upper cover and base together achieves a sealed connection of the housing, completely isolating the external environment from the internal components and significantly improving the sensor's environmental adaptability. The design of the upper and lower positioning steps allows for rapid coaxial positioning of the upper cover, base, and outer sleeve, ensuring assembly accuracy during welding and preventing uneven stress on internal components due to welding misalignment. Simultaneously, the outer sleeve also strengthens the housing, improving the sensor's overall impact resistance and extending its service life.

[0013] As a preferred implementation of a flattened three-dimensional acceleration and three-dimensional force composite sensor, the upper surface of the quartz glass plate is provided with a conductive layer. This conductive layer includes multiple signal receiving areas and signal transmission areas. The signal receiving areas overlap with and are in contact with the corresponding detection elements: the longitudinal effect acceleration detection element, the shear effect acceleration detection element, the longitudinal effect force detection element, and the shear effect force detection element. The signal transmission areas are segment-shaped, with one end connected to the corresponding signal receiving area and the other end connected to a signal connector located on the outer casing. The conductive layer is formed on the quartz glass plate through plating. The signal receiving areas are precisely fitted to each detection element, maximizing the reception of the charge signals output by the detection elements and reducing signal loss. The segment-shaped signal transmission areas are neatly arranged, avoiding signal interference caused by wire crossings and ensuring signal transmission stability. Simultaneously, the signal transmission areas are directly connected to the signal connector on the outer casing, eliminating the need for additional internal wiring, further reducing the size of the composite sensor and improving its reliability.

[0014] As a preferred implementation of a flattened three-dimensional acceleration and three-dimensional force composite sensor, the longitudinal effect force detection element and the shear effect force detection element are arranged concentrically in a fan-shaped ring, and the shear effect direction of the shear effect force detection element is radial to the fan-shaped ring; the longitudinal effect acceleration detection element and the shear effect acceleration detection element are rectangular, and the shear effect direction of the shear effect acceleration detection element is set along the long side of the rectangle, and the shear effect directions of the shear effect acceleration detection elements are connected end to end. The force detection element adopts a fan-shaped concentric arrangement with the shear effect direction being radial. This allows it to more evenly bear the radial shear force of the shell, reduce local stress concentration, avoid damage to the element due to uneven force, and extend the element's service life. At the same time, the fan-shaped structure can make full use of the annular space and improve the coverage of force detection. The acceleration detection element adopts a rectangular design with the shear effect direction connected end to end, forming a closed shear force sensing loop. This can quickly and comprehensively capture misaligned shear forces in the X and Y directions, improving the response speed and accuracy of acceleration detection. Both element shapes are designed to fit the overall annular layout, ensuring the compactness of the internal structure and maintaining the flattened characteristics.

[0015] On the other hand, the present invention also provides a detection method for the above-mentioned flattened three-dimensional acceleration and three-dimensional force composite sensor. In the direction of the central axis, the two ends of the composite sensor are installed between two connection points of the object being measured. The central axis direction is defined as the Z-direction. In a plane perpendicular to the Z-direction, there are mutually perpendicular X and Y directions. The detection method includes: acceleration detection: the object being measured causes the composite sensor to generate an instantaneous displacement. Simultaneously, the pre-compression structure of the acceleration sensor has inertia and maintains its original position when the instantaneous displacement occurs. The Z-direction component of the displacement generates a Z-axis component under the action of the pre-compression structure of the acceleration sensor. For pressure fluctuations, the longitudinal effect acceleration detection element generates and outputs a charge signal; the X and Y components of displacement cause misalignment between the shell and the pre-compression structure of the acceleration sensor, and the shear effect acceleration detection element generates and outputs a charge signal. For force detection: a relative instantaneous displacement occurs between the two connection points of the measured object. The Z component of the instantaneous displacement compresses or stretches the shell, causing pressure fluctuations in the longitudinal effect force detection element, which generates and outputs a charge signal; the X and Y components of the instantaneous displacement cause misalignment at both ends of the shell, and the shear effect force detection element generates and outputs a charge signal. This detection method, by clearly defining the detection principles in the Z, X, and Y directions, maps acceleration and force detection to displacement components in different directions, achieving precise differentiation between the two physical quantities, avoiding signal confusion, and improving the accuracy of the detection data.

[0016] As can be seen from the above embodiments, the advantages of this invention are as follows: By integrating the longitudinal and shear effect sensitive elements coplanarly, three-dimensional detection is achieved with a single-layer element thickness, significantly reducing the overall thickness of the sensor, adapting to narrow installation spaces. Simultaneously, the detection elements are arranged in an orderly manner along the central axis and precisely partitioned using inner and outer insulating rings, avoiding signal interference. Regarding assembly and pre-compression, a separate design for the top cover and base is adopted. The force sensor pre-compression structure is directly formed by pressing the top cover, and the pre-compression adjustment of the acceleration sensor is achieved through the threaded engagement of the central column, mass block, and tightening nut. This eliminates the need for complex components, simplifies the structure, allows for precise calibration of the pre-compression pressure, prevents rebound, and the flat surface of the top cover wrench improves assembly and maintenance convenience. In terms of element and material selection, the lithium niobate crystal sheet for force detection ensures the force detection range and stability, while the piezoelectric ceramic sheet for acceleration detection improves sensitivity and response speed. Both are compact and lightweight, balancing performance and economy. For protection and signal transmission, the welded sealing design of the outer sleeve isolates the influence of harsh environments and enhances impact resistance. The conductive layer on the quartz glass sheet transmits signals through a "receiving area + transmission area." The structure reduces signal loss and interference, eliminates the need for additional wires, and further reduces the size. The shape of the detection element is adapted to the ring layout, with the fan-shaped force detection element receiving uniform force and the rectangular acceleration detection element forming a closed sensing loop in the detection direction, improving the detection coverage and response accuracy. The detection method, by clearly defining the detection principles in the Z, X, and Y directions, accurately distinguishes between acceleration and force signals, avoiding confusion. Overall, it achieves multiple benefits such as sensor flattening, high detection accuracy, convenient installation, strong environmental adaptability, and cost-effectiveness, making it suitable for extreme detection environments with high temperature and high pressure. Attached Figure Description To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a cross-sectional structural diagram of a specific embodiment of the present invention.

[0018] Figure 2 This is an exploded view of a specific embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the structure of the upper cover in a specific embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the base structure in a specific embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the conductive layer in a specific embodiment of the present invention.

[0022] Explanation of main figure symbols 00. Central axis, 1-Outer sleeve, 2-Upper cover, 2-1. Receiving cavity, 2-2. Threaded hole, 2-3. Wrench plane, 2-4. Upper positioning step, 3-Base, 3-1. Central column, 3-2. External thread, 3-3. Lower positioning step, 4-Quartz glass plate, 4-1. Signal receiving area, 4-2. Signal transmission area, 5-Shear effect force detection element, 6-Outer insulating ring of force sensor, 7-Longitudinal effect force detection element, 8-Inner insulating ring of force sensor, 9-Shear effect acceleration detection element, 10-Outer insulating ring of acceleration sensor, 11-Longitudinal effect acceleration detection element, 12-Inner insulating ring of acceleration sensor, 13-Mass block, 14-Tightening nut, 15-Cable shell, 16-Six-core metal cable. Detailed Implementation

[0023] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0024] Example 1 like Figure 1 , 2 As shown, a flattened three-dimensional acceleration and three-dimensional force composite sensor includes a housing. Inside the housing are a force sensor module and an acceleration sensor module. The composite sensor is cylindrical in shape, and a central axis O0 is defined within the housing. The force sensor module includes four shear force detection elements 5 and four longitudinal force detection elements 7. The four shear force detection elements 5 and the four longitudinal force detection elements 7 are coplanar, and this plane is perpendicular to the central axis O0. The four shear force detection elements 5 are evenly arranged around the central axis O0, and the four longitudinal force detection elements 7 are also evenly arranged coplanarly around the central axis O0. This coplanar design achieves three-dimensional detection with a single-layer sensitive element thickness, significantly reducing the overall thickness of the sensor. This makes it suitable for narrow installation spaces, especially for equipment scenarios with limited space, such as reactors. Furthermore, it reduces structural stress caused by thermal expansion in high-temperature environments, preventing sensor structural damage or performance degradation. An insulating ring 6 is provided on the outer side of the force sensor between the shear effect force detection element 5 and the longitudinal effect force detection element 7, which can realize precise partitioning of the two force detection elements and avoid signal interference. The upper and lower sides of the shear effect force detection element 5 and the longitudinal effect force detection element 7 are provided with force sensor pre-compression structures to ensure stable force on the elements. Moreover, both use lithium niobate crystal wafers, which have excellent piezoelectric properties and mechanical stability, and can maintain stable signal output even when subjected to large external forces, effectively improving the range and accuracy of force detection.

[0025] The acceleration sensor module includes four shear effect acceleration detection elements 9 and four longitudinal effect acceleration detection elements 11. The four shear effect acceleration detection elements 9 and the four longitudinal effect acceleration detection elements 11 are coplanar, and this plane is perpendicular to the central axis 00. The four shear effect acceleration detection elements 9 are evenly arranged around the central axis 00, and the four longitudinal effect acceleration detection elements 11 are also evenly arranged coplanarly around the central axis 00. This coplanar layout further enhances the sensor's flatness advantage and reduces its volume. An outer insulating ring 10 is provided between the shear effect acceleration detection elements 9 and the longitudinal effect acceleration detection elements 11 to achieve signal isolation between the acceleration detection elements. Pre-compression structures on the upper and lower sides of the acceleration sensor ensure stable force on the elements. Both use piezoelectric ceramic sheets, which have high piezoelectric coefficients and fast response speeds, enabling rapid capture of instantaneous acceleration changes and significantly improving the sensitivity of acceleration detection.

[0026] The shear force detection element 5, the longitudinal force detection element 7, the shear acceleration detection element 9, and the longitudinal acceleration detection element 11 are all coplanarly arranged, sequentially along a direction away from the central axis O0, namely the longitudinal acceleration detection element 11, the shear acceleration detection element 9, the longitudinal force detection element 7, and the shear force detection element 5. An inner insulating ring 8 of the force sensor is provided between the shear acceleration detection element 9 and the longitudinal force detection element 7. This ring-shaped, progressive, and orderly arrangement fully utilizes the internal planar space of the housing, eliminating the need for additional radial or axial dimensions. While maintaining a flat structure, the double insulating ring design (outer insulating ring 6 and inner insulating ring 8 of the force sensor, and outer insulating ring 10 of the acceleration sensor) achieves signal isolation between the force and acceleration detection modules, further improving the accuracy of the detection data. Furthermore, the longitudinal effect force detection element 7 and the shear effect force detection element 5 are arranged concentrically in a fan-shaped ring, with the shear effect direction being the radial direction of the fan-shaped ring. This allows for more uniform bearing of the radial shear force of the shell, reducing local stress concentration, preventing damage to the elements due to uneven force distribution, extending service life, and improving the force detection coverage. The longitudinal effect acceleration detection element 11 and the shear effect acceleration detection element 9 are rectangular, with the shear effect direction set along the long side of the rectangle. This allows for rapid and comprehensive capture of X and Y shear forces, improving the acceleration detection response speed and accuracy. Both shape designs perfectly match the overall ring layout, ensuring the compactness of the internal structure.

[0027] like Figure 2 , 3 As shown in Figures 1 and 4, the housing includes an upper cover 2, a base 3, and an outer sleeve 1. The upper surface of the base 3 is provided with a quartz glass plate 4, on which all detection elements are placed. The quartz glass plate has high strength and high insulation properties, providing a flat and stable mounting base for the elements and avoiding detection errors caused by uneven base surfaces. At the same time, it serves as the substrate for the subsequent conductive layer, providing a reliable carrier for signal transmission. The upper cover 2 and the base 3 are fixedly connected, and the upper cover 2 is pressed against the force detection element to form a force sensor pre-compression structure. This eliminates the need for additional complex pre-compression components, simplifying the internal structure while ensuring that the force detection element is always under stable force, thus guaranteeing the consistency of force detection data. A central column 3-1 is provided at the center of the upper surface of the base 3, around which the acceleration detection elements are arranged. The central column can position the elements, ensuring installation coaxiality and reducing detection errors caused by eccentricity. An inner insulating ring 12 of the acceleration sensor is provided between the longitudinal effect force detection element 7 and the central column 3-1 to further enhance the signal isolation effect. The accelerometer preload structure includes a mass block 13, which is fitted around the inner insulating ring 12 of the accelerometer. The upper end of the central column 3-1 has an external thread 3-2, and a threaded tightening nut 14 is pressed against the mass block 13. The bottom surface of the mass block 13 presses against the acceleration detection element. This internally threaded tightening preload structure replaces the traditional preload fixture, avoiding scratches on the housing or causing the top cover to rebound during fixture removal. It effectively prevents preload loss and allows for flexible adjustment of the preload pressure via the tightening nut, enabling precise control of sensor sensitivity, linearity, and other technical indicators, ensuring excellent performance. The bottom center of the top cover 2 has a receiving cavity 2-1, which encloses the central column 3-1, mass block 13, and tightening nut 14, preventing external dust and moisture from corroding the internal components, extending their service life, and allowing for a more compact internal component layout without increasing the housing volume. The length of the external thread 3-2 is greater than the thickness of the tightening nut 14, and the threaded hole 2-2 at the center of the top surface of the receiving cavity 2-1 is connected to the external thread 3-2. The double thread connection not only enhances the connection stability between the top cover and the base, but also allows for secondary adjustment of the internal pre-pressure by rotating the top cover, achieving fine calibration of the pre-pressure and further improving the detection accuracy. The wrench plane 2-3 on the outer circumference of the top cover 2 provides convenience for gripping and rotating during installation, avoids slippage, improves assembly efficiency, and facilitates subsequent disassembly and maintenance.

[0028] The upper cover 2 and the base 3 are located within the outer sleeve 1, with their outer circumferential surfaces fitting against the inner circumferential surface of the outer sleeve 1. The upper positioning step 2-4 of the upper cover 2 is fitted and welded to the upper edge of the outer sleeve 1, and the lower positioning step 3-3 of the base 3 is fitted and welded to the lower edge of the outer sleeve 1. The upper and lower positioning steps enable rapid coaxial positioning of the upper cover, base, and outer sleeve, ensuring welding assembly accuracy and preventing uneven stress on internal components due to welding misalignment. The welding connection method achieves a sealed connection of the shell, completely isolating the external environment from the internal components, making it particularly suitable for harsh environments such as humidity and dust, significantly improving the sensor's environmental adaptability. At the same time, the outer sleeve provides enhanced protection for the shell, improving overall impact resistance and extending service life.

[0029] like Figure 5 As shown, the upper surface of the quartz glass plate 4 is provided with a conductive layer, which includes multiple signal receiving areas and signal transmission areas. The multiple signal receiving areas are the same as and in contact with the coverage areas of each detection element. The signal transmission area is linear, with one end connected to the signal receiving area and the other end connected to a signal connector on the housing. The signal connector includes a six-core metal cable 16, which is mounted to the housing through a cable shell 15. Based on this, the sensor does not require additional complex wiring connections, which not only reduces internal space usage but also lowers the risk of failure due to wire aging or poor contact, thus improving sensor reliability.

[0030] The conductive layer is a sputtered platinum layer, which is formed by sputtering a platinum conductive coating using a platinum target: First, high-temperature tape is pasted on the surface of a quartz glass plate. Then, a laser device is used to etch the high-temperature tape, precisely removing excess tape to expose the target area of ​​the quartz glass surface to be sputtered. The quartz glass, after laser etching and removal of excess high-temperature tape, is cleaned to remove residual tape debris, dust, and other impurities. After cleaning, the quartz glass is dried to ensure its surface is dry. Finally, the dried quartz glass is placed in a magnetron sputtering chamber, and a platinum coating is sputtered on the exposed target area of ​​the quartz glass using magnetron sputtering technology with platinum as the target material. This coating serves as the electrode conductive layer of the sensor, used to realize the reception and transmission of signals from the sensitive element, and removes excess high-temperature tape.

[0031] Example 2 This embodiment provides a detection method for the flattened three-dimensional acceleration and three-dimensional force composite sensor described in Embodiment 1. In the direction of the central axis O0, the two ends of the composite sensor are installed between two connection points of the object being measured. The direction of the central axis O0 is defined as the Z-direction. Within the plane perpendicular to the Z-direction, there are mutually perpendicular X and Y directions. The detection method includes: Acceleration detection: The object under test causes the composite sensor to generate instantaneous displacement. At the same time, the pre-compression structure of the acceleration sensor has inertia and maintains its original position when the instantaneous displacement occurs. The Z-axis component of the displacement generates Z-axis pressure fluctuation under the action of the pre-compression structure of the acceleration sensor. The longitudinal effect acceleration detection element 11 generates and outputs charge signal. The X and Y-axis components of the displacement cause the shell and the pre-compression structure of the acceleration sensor to be misaligned. The shear effect acceleration detection element 9 generates and outputs charge signal. Force detection: A relative instantaneous displacement is generated between the two connection points of the object being tested. The Z-axis component of the instantaneous displacement compresses or stretches the shell, causing the longitudinal effect force detection element 7 to generate pressure fluctuations. The longitudinal effect force detection element 7 generates and outputs a charge signal. The X and Y-axis components of the instantaneous displacement cause misalignment at both ends of the shell, and the shear effect force detection element 5 generates and outputs a charge signal.

[0032] As can be seen from the above embodiments, the beneficial effects of the present invention are as follows: This solution achieves three-dimensional detection with a single-layer sensitive element thickness by coplanar integration of force and acceleration detection elements, significantly reducing the overall thickness and adapting to narrow spaces such as reactors, while reducing structural stress caused by thermal expansion at high temperatures; the integrated design enables simultaneous measurement of two physical quantities without the need for separate installation structures, reducing space occupation and installation steps, eliminating spatial errors and signal delays from independent installation, and improving data synchronization and measurement accuracy. It adopts an internal threaded tightening pre-compression structure, with a threaded fit between the top cover and the base, replacing traditional pre-compression fixtures to prevent pre-compression force loss. The pre-compression force can be flexibly adjusted to precisely control sensitivity, linearity, and other indicators. The wrench plane on the top cover also improves assembly and maintenance efficiency; multiple insulating rings enable precise partitioning of each detection element, avoiding signal interference; the fan-shaped force detection element and the rectangular acceleration detection element are designed to be compatible, respectively improving the uniformity of force detection and the response speed of acceleration detection. In addition, the welded sealing structure of the outer sleeve, combined with the upper and lower positioning steps, ensures coaxial assembly accuracy and shell sealing, isolates the effects of harsh environments, and improves impact resistance and environmental adaptability. The sputtered platinum conductive layer on the quartz glass substrate forms an interface fusion thin film structure, which is superior to traditional electrode sheets, reduces signal loss and interference, eliminates the need for additional wires, and reduces the risk of failure. Furthermore, the selection of lithium niobate crystal sheet and piezoelectric ceramic sheet respectively ensures the accuracy of force detection range and the sensitivity of acceleration detection, taking into account performance, reliability and economy as a whole.

[0033] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flattened three-dimensional acceleration and three-dimensional force composite sensor, comprising a housing, wherein a force sensor module and an acceleration sensor module are disposed inside the housing, and the housing has a central axis (00), characterized in that: The force sensor module includes four shear force detection elements (5) and four longitudinal force detection elements (7). The four shear force detection elements (5) and the four longitudinal force detection elements (7) are all coplanar and the plane is perpendicular to the central axis (00). The four shear force detection elements (5) are evenly arranged around the central axis (00), and the four longitudinal force detection elements (7) are evenly arranged coplanarly around the central axis (00). An outer insulating ring (6) of the force sensor is provided between the shear force detection elements (5) and the longitudinal force detection elements (7). A force sensor pre-compression structure is provided on the upper and lower sides of the shear force detection elements (5) and the longitudinal force detection elements (7). The acceleration sensor module includes four shear effect acceleration detection elements (9) and four longitudinal effect acceleration detection elements (11). The four shear effect acceleration detection elements (9) and the four longitudinal effect acceleration detection elements (11) are all coplanar and the plane is perpendicular to the central axis (00). The four shear effect acceleration detection elements (9) are uniformly arranged around the central axis (00), and the four longitudinal effect acceleration detection elements (11) are coplanar and uniformly arranged around the central axis (00). An outer insulating ring (10) of the acceleration sensor is provided between the shear effect acceleration detection elements (9) and the longitudinal effect acceleration detection elements (11). An acceleration sensor pre-compression structure is provided on the upper and lower sides of the shear effect acceleration detection elements (9) and the longitudinal effect acceleration detection elements (11).

2. The flattened three-dimensional acceleration and three-dimensional force composite sensor according to claim 1, characterized in that, The shear force detection element (5), the longitudinal force detection element (7), the shear acceleration detection element (9), and the longitudinal acceleration detection element (11) are all coplanarly arranged, and are arranged sequentially along the direction away from the central axis (00) as the longitudinal acceleration detection element (11), the shear acceleration detection element (9), the longitudinal force detection element (7), and the shear force detection element (5); an inner insulating ring (8) of the force sensor is provided between the shear acceleration detection element (9) and the longitudinal force detection element (7).

3. The flattened three-dimensional acceleration and three-dimensional force composite sensor according to claim 1, characterized in that, The housing includes a top cover (2) and a base (3). The upper surface of the base (3) is provided with a quartz glass plate (4). The shear force detection element (5), the longitudinal force detection element (7), the shear acceleration detection element (9), and the longitudinal acceleration detection element (11) are all placed on the quartz glass plate (4). The top cover (2) and the base (3) are fixedly connected. The top cover (2) is pressed against the shear force detection element (5) and the longitudinal force detection element (7) to form the force sensor pre-compression structure.

4. The flattened three-dimensional acceleration and three-dimensional force composite sensor according to claim 3, characterized in that, A central column (3-1) is provided at the center of the upper surface of the base (3). The shear effect acceleration detection element (9) and the longitudinal effect acceleration detection element (11) are arranged around the central column (3-1). An inner insulating ring (12) of the acceleration sensor is provided between the longitudinal effect force detection element (7) and the central column (3-1). The acceleration sensor pre-compression structure includes a mass block (13). The mass block (13) is sleeved on the outside of the inner insulating ring (12) of the acceleration sensor. The upper part of the central column (3-1) The end is provided with an external thread (3-2), and a tightening nut (14) is installed on the external thread (3-2) by thread. The tightening nut (14) is pressed on the top of the mass block (13), and the bottom surface of the mass block (13) is pressed on the top of the shear effect acceleration detection element (9) and the longitudinal effect acceleration detection element (11). The bottom surface of the upper cover (2) is provided with a receiving cavity (2-1), and the central column (3-1), the mass block (13) and the tightening nut (14) are all located in the receiving cavity (2-1).

5. The flattened three-dimensional acceleration and three-dimensional force composite sensor according to claim 4, characterized in that, The length of the external thread (3-2) is greater than the thickness of the tightening nut (14). The top surface of the receiving cavity (2-1) is provided with a threaded hole (2-2). The threaded hole (2-2) is threadedly connected to the external thread (3-2). The outer peripheral surface of the upper cover (2) is also provided with a wrench plane (2-3).

6. The flattened three-dimensional acceleration and three-dimensional force composite sensor according to claim 1, characterized in that, The shear force detection element (5) and the longitudinal force detection element (7) are lithium niobate crystal sheets; the shear acceleration detection element (9) and the longitudinal acceleration detection element (11) are piezoelectric ceramic sheets.

7. The flattened three-dimensional acceleration and three-dimensional force composite sensor according to claim 3, characterized in that, The housing also includes an outer sleeve (1), the upper cover (2) and the base (3) are located in the outer sleeve (1), the outer peripheral surfaces of the upper cover (2) and the base (3) are in contact with the inner peripheral surface of the outer sleeve (1); the top edge of the outer peripheral surface of the upper cover (2) is provided with an upper positioning step (2-4), the upper positioning step (2-4) is in contact with the upper edge of the outer sleeve (1) and welded and fixed, the bottom edge of the outer peripheral surface of the base (3) is provided with a lower positioning step (3-3), the lower positioning step (3-3) is in contact with the lower edge of the outer sleeve (1) and welded and fixed.

8. The flattened three-dimensional acceleration and three-dimensional force composite sensor according to claim 3, characterized in that, The upper surface of the quartz glass plate (4) is provided with a conductive layer, which includes multiple signal receiving areas (4-1) and signal transmission areas (4-2). The multiple signal receiving areas (4-1) are respectively the same as the coverage areas of the longitudinal effect acceleration detection element (11), the shear effect acceleration detection element (9), the longitudinal effect force detection element (7) and the shear effect force detection element (5) and are in contact with the corresponding detection elements. The signal transmission area (4-2) is in the shape of a line segment, with one end of each line segment connected to the corresponding signal receiving area (4-1) and the other end connected to the signal connector located on the outer shell.

9. The flattened three-dimensional acceleration and three-dimensional force composite sensor according to claim 1, characterized in that, The longitudinal force detection element (7) and the shear force detection element (5) are arranged in a fan-shaped ring and concentrically. The shear effect direction of the shear force detection element (5) is the radial direction of the fan-shaped ring. The longitudinal acceleration detection element (11) and the shear acceleration detection element (9) are rectangular. The shear effect direction of the shear acceleration detection element (9) is set along the long side of the rectangle. The shear effect directions of the shear acceleration detection element (9) are connected end to end.

10. A detection method for a flattened three-dimensional acceleration and three-dimensional force composite sensor as described in claims 1-9, characterized in that, Along the central axis (00), the two ends of the composite sensor are installed between the two connection points of the object being measured. The central axis (00) direction is defined as the Z direction. Within the plane perpendicular to the Z direction, there are mutually perpendicular X and Y directions. The detection method includes: Acceleration detection: The object under test drives the composite sensor to generate instantaneous displacement. At the same time, the pre-compression structure of the acceleration sensor has inertia and maintains its original position when the instantaneous displacement occurs. The Z-axis component of the displacement generates Z-axis pressure fluctuation under the action of the pre-compression structure of the acceleration sensor. The longitudinal effect acceleration detection element (11) generates and outputs charge signal. The X and Y-axis components of the displacement cause the shell and the pre-compression structure of the acceleration sensor to be misaligned. The shear effect acceleration detection element (9) generates and outputs charge signal. Force detection: A relative instantaneous displacement is generated between the two connection points of the object under test. The Z-axis component of the instantaneous displacement squeezes or stretches the shell, causing the longitudinal effect force detection element (7) to generate pressure fluctuations. The longitudinal effect force detection element (7) generates and outputs a charge signal. The X and Y-axis components of the instantaneous displacement cause misalignment at both ends of the shell. The shear effect force detection element (5) generates and outputs a charge signal.

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