High stiffness ring shear piezoelectric sensor

Abstract

The utility model provides a kind of high stiffness ring shear piezoelectric sensor, including base, the base includes base and center column, the center column is coaxially arranged with base and extends along axial from the end surface of base, and inside to outside is sequentially set with inner piezoelectric ring, annular mass, outer piezoelectric ring and tightening ring by the center column, a plurality of tightening grooves are provided on the annular mass, the tightening groove extends radially from the inner ring or outer ring of annular mass, and the tightening groove is blind groove;So that the connection of inner piezoelectric ring, annular mass, outer piezoelectric ring is more closely, improves the transverse stiffness of ring shear piezoelectric sensor, improves the resonant frequency of ring shear piezoelectric sensor.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, specifically to a high-stiffness ring shear piezoelectric sensor. Background Technology

[0002] Piezoelectric sensors are key devices based on the piezoelectric effect, converting physical quantities such as force, pressure, and acceleration into electrical signals. Among them, the ring shear piezoelectric sensor is a common and widely used type, capable of achieving a wide frequency response range, high sensitivity, and good linearity. It has been standardized in fields such as mechanical condition monitoring, equipment fault diagnosis, aerospace testing, and automotive NVH testing. A ring shear piezoelectric sensor typically has a base and a central post. A ring-shaped mass block and a piezoelectric ring are arranged around the central post, and a nut or cap is placed on top to apply preload, ensuring tight contact and preventing separation under both static and dynamic conditions.

[0003] In the aforementioned ring shear structure, the mass block is an inertial element, while the piezoelectric ring and preload nut together provide elastic restoring force. The resonant frequencies of these elements determine the upper limit of the piezoelectric sensor. However, due to the inherent brittleness of the piezoelectric ceramic material, the need for an insulating layer between the piezoelectric ring and the metal component to ensure insulation and stress uniformity, and the limited lateral bending stiffness of the preload nut, the upper limit of the lateral stiffness of the entire ring shear piezoelectric sensor cannot be very high. When the lateral stiffness is insufficient, if there is lateral vibration perpendicular to the axis, the mass block is prone to lateral displacement, thereby applying unexpected lateral forces or bending moments to the piezoelectric element. This interferes with the measurement direction of shear stress, affecting the accuracy of the piezoelectric element's output signal, introducing measurement errors, and reducing the overall sensitivity and long-term stability of the sensor.

[0004] Therefore, it is necessary to improve the above-mentioned classic structure to overcome its insufficient stiffness in order to meet the needs of the ever-changing sensor market. Summary of the Invention

[0005] The purpose of this invention is to provide a high-rigidity ring shear piezoelectric sensor to solve the above-mentioned problems.

[0006] The technical solution adopted in this utility model is as follows: A high-stiffness ring shear piezoelectric sensor includes a base, the base comprising a base plate and a central column, the central column being coaxially arranged with the base plate and extending axially from the end face of the base plate, and an inner piezoelectric ring, an annular mass block, an outer piezoelectric ring, and a tightening ring sequentially arranged from the inside to the outside around the central column, with a plurality of tightening grooves provided on the annular mass block, the tightening grooves extending radially from the inner or outer ring of the annular mass block, the tightening grooves being blind grooves.

[0007] As a further improvement of the present invention, the tightening groove includes an inner tightening groove and an outer tightening groove. The inner tightening groove extends radially from the inner ring of the annular mass block, and the outer tightening groove extends radially from the outer ring of the annular mass block. A plurality of the inner tightening grooves are evenly distributed along the circumference of the inner ring of the annular mass block, and a plurality of the outer tightening grooves are evenly distributed along the circumference of the outer ring of the annular mass block.

[0008] As a further improvement of this utility model, the inner tightening groove and the outer tightening groove are arranged alternately.

[0009] As a further improvement of this utility model, both the inner tightening groove and the outer tightening groove are straight grooves.

[0010] As a further improvement of this utility model, a first through groove is provided on the annular mass block, and the first through groove penetrates the annular mass block in both the radial and axial directions. A second through groove is provided on the inner piezoelectric ring, and the second through groove penetrates the inner piezoelectric ring in both the radial and axial directions. A third through groove is provided on the outer piezoelectric ring, and the third through groove penetrates the outer piezoelectric ring in both the radial and axial directions.

[0011] As a further improvement of the present invention, a plurality of arc-shaped plates are also provided on the base. The plurality of arc-shaped plates are evenly distributed around the central column, and the plurality of arc-shaped plates are coaxial with the central column. A contraction gap is formed between adjacent arc-shaped plates, and the arc-shaped plates are disposed between the tightening ring and the outer piezoelectric ring.

[0012] As a further improvement of this utility model, the shrinkage gap is provided between adjacent inner tightening grooves and outer tightening grooves.

[0013] As a further improvement of this utility model, a connector assembly is provided inside the base, and a cable is provided between the connector assembly and the annular mass block for connection.

[0014] As a further improvement of this utility model, there are wiring gaps between the bottom surface of the tightening ring, the bottom surface of the outer piezoelectric ring, the bottom surface of the annular mass block and the bottom surface of the inner piezoelectric ring and the top surface of the base. A wiring channel is provided in the base, the wiring channel is connected to the wiring gap, and the cable is arranged in the wiring channel and the wiring gap.

[0015] As a further improvement of the present invention, an upper cover is provided on the base, and the upper cover and the base cooperate to form an accommodating space. The central column, inner piezoelectric ring, annular mass block, outer piezoelectric ring and tightening ring are all arranged in the accommodating space, and a fixing hole is provided on the base.

[0016] The beneficial effects of this utility model are as follows: By creating groove-like structures on the inner piezoelectric ring, the annular mass block, and the outer piezoelectric ring to obtain deformation tightening space, and by adding several arc-shaped plates between the tightening ring and the outer piezoelectric ring to form a shrinkage gap, the lateral tightening force is enhanced, making the connection between the inner piezoelectric ring, the annular mass block, and the outer piezoelectric ring tighter, thereby improving the lateral stiffness of the ring shear piezoelectric sensor and increasing its resonant frequency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a high-rigidity ring shear piezoelectric sensor; Figure 2 This is a schematic diagram of the internal structure of a high-rigidity ring shear piezoelectric sensor; Figure 3 This is an axial cross-sectional view of a high-stiffness ring shear piezoelectric sensor; Figure 4 This is a schematic diagram of the structure of the ring-shaped mass block; Figure 5 This is a schematic diagram of the external pressure ring; Figure 6 This is a schematic diagram of the internal pressure ring structure; Figure 7 This is a schematic diagram of the base structure; Figure 8 This is an axial sectional view of the base.

[0018] Wherein: 1-base, 101-base, 102-center post, 103-arc plate, 104-shrinkage gap, 105-wiring channel, 106-connector mounting hole, 107-fixing hole, 2-inner piezoelectric ring, 201-second through groove, 3-annular mass block, 301-inner tightening groove, 302-outer tightening groove, 303-first through groove, 4-outer piezoelectric ring, 401-third through groove, 5-tightening ring, 6-wiring gap, 7-connector assembly, 701-connector housing, 702-conductive core, 703-insulating layer, 8-cable, 9-top cover. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the protection scope of the present invention.

[0020] If the description of this utility model involves directions (e.g., up, down, left, right, front, back, outside, inside, etc.), then the directions involved need to be defined. For example, "To clearly express the position and direction described in this utility model, the operator of the instrument is used as a reference, the end closer to the operator is the proximal end, and the end farther from the operator is the distal end." Or, the paper can be used as a reference. Of course, if the positional relationship between the two is defined by mutual reference in the subsequent description, then this definition is not required.

[0021] A high-stiffness ring shear piezoelectric sensor, such as Figures 1-3 As shown, the ring shear piezoelectric sensor includes a base 1, which includes a base 101 and a central column 102. The central column 102 is coaxially arranged with the base 101 and extends axially from the end face of the base 101. An inner piezoelectric ring 2, an annular mass block 3, an outer piezoelectric ring 4, and a tightening ring 5 are sequentially arranged from the inside to the outside around the central column 102. The inner piezoelectric ring 2 and the outer piezoelectric ring 4 are both axially polarized and have the same polarization direction. Several tightening grooves are provided on the annular mass block 3. The tightening grooves extend radially from the inner or outer ring of the annular mass block 3. The tightening grooves are blind grooves, which are similar to blind holes. The blind grooves do not penetrate the annular mass block 3, or in other words, the blind grooves have a bottom inside the annular mass block 3. During assembly, a circumferential tightening force is applied to the annular mass block 3. Due to the presence of the tightening groove, the annular mass block 3 has a tendency to shrink radially in either the inner or outer ring. This allows the inner piezoelectric ring 2 to be more tightly clamped onto the central column 102 or to be covered by the outer piezoelectric ring 4, which has a smaller diameter (the outer piezoelectric ring 4 mentioned here refers to a diameter smaller than the outer ring diameter of the annular mass block 3 when not under force). Then, when the tightening ring 5 is covered onto the outer piezoelectric ring 4, the inner piezoelectric ring 2, the annular mass block 3, and the outer piezoelectric ring 4 are locked, enhancing the lateral stiffness and resonant frequency of the ring shear piezoelectric sensor.

[0022] As one embodiment of this utility model, such as Figure 4As shown, the tightening groove includes an inner tightening groove 301 and an outer tightening groove 302. The inner tightening groove 301 extends radially from the inner ring of the annular mass block 3 to the outer ring, and the outer tightening groove 302 extends radially from the outer ring of the annular mass block 3 to the inner ring. A plurality of the inner tightening grooves 301 are evenly distributed along the circumference of the inner ring of the annular mass block 3, and a plurality of the outer tightening grooves 302 are evenly distributed along the circumference of the outer ring of the annular mass block 3. When a tightening force is applied to the annular mass block 3 in the radial direction toward the central column 102, the inner ring of the annular mass block 3 can be squeezed into the inner tightening groove 301 for radial contraction, and the outer ring of the annular mass block 3 can be squeezed into the outer tightening groove 302 for radial contraction.

[0023] Furthermore, the inner tightening groove 301 and the outer tightening groove 302 are arranged alternately. The alternate arrangement is such that an outer tightening groove 302 is provided between the radial extension lines of two adjacent inner tightening grooves 301, and correspondingly, an inner tightening groove 301 is provided between the radial extension lines of two adjacent outer tightening grooves 302. Thus, when the annular mass block 3 is deformed by external force, it can shrink more uniformly.

[0024] In one embodiment of this utility model, both the inner tightening groove 301 and the outer tightening groove 302 are straight grooves. Neither the inner tightening groove 301 nor the outer tightening groove 302 radially penetrates the annular mass block 3. Both the inner tightening groove 301 and the outer tightening groove 302 axially penetrate the annular mass block 3.

[0025] In one embodiment of this invention, the tightening ring 5 is made of shape memory alloy and beryllium bronze, used to lock the inner piezoelectric ring 2, outer piezoelectric ring 4, and annular mass block 3 on its inner side. At a preset activation temperature, the tightening ring 5, made of shape memory alloy, undergoes an austenitic phase transformation, causing its inner diameter to shrink, thereby applying a strong and uniform radial compressive stress to the inner components, achieving initial locking. Beryllium bronze has excellent elastic modulus and anti-relaxation ability, providing a durable and stable elastic holding force after locking, compensating for the preload attenuation that may be caused by mechanical vibration or temperature fluctuations. The two work together to ensure that the inner piezoelectric ring 2, outer piezoelectric ring 4, and annular mass block 3 maintain a high-precision tight connection under complex working conditions, preventing loosening and fretting wear.

[0026] As one embodiment of this utility model, such as Figures 4-6As shown, a first through groove 303 is provided on the annular mass block 3, which penetrates the annular mass block 3 in both the radial and axial directions. A second through groove 201 is provided on the inner piezoelectric ring 2, which penetrates the inner piezoelectric ring 2 in both the radial and axial directions. A third through groove 401 is provided on the outer piezoelectric ring 4, which penetrates the outer piezoelectric ring 4 in both the radial and axial directions. This allows the annular mass block 3, the inner piezoelectric ring 2, and the outer piezoelectric ring 4 to have space for deformation and contraction when subjected to circumferential tightening force. As a result, the inner piezoelectric ring 2 can tightly wrap around the central column 102, the annular mass block 3 can tightly wrap around the inner piezoelectric ring 2, and the outer piezoelectric ring 4 can tightly wrap around the annular mass block 3, and is finally shaped and tightened by the tightening ring 5.

[0027] As one embodiment of this utility model, such as Figure 2 , 7 As shown, a plurality of arc-shaped plates 103 are also provided on the base 101. The plurality of arc-shaped plates 103 are evenly distributed circumferentially around the central column 102 and arranged in a ring. A contraction gap 104 is formed between adjacent arc-shaped plates 103. The arc-shaped plates 103 are disposed between the tightening ring 5 and the outer piezoelectric ring 4. The inner diameter of the arc-shaped plate 103 is the same as the outer diameter of the outer piezoelectric ring 4, and the outer diameter of the arc-shaped plate 103 is the same as the inner diameter of the tightening ring 5. When subjected to circumferential tightening force, the contraction gap 104 allows two adjacent arc-shaped plates 103 to have space for radial deformation and contraction within the contraction gap 104, thereby tightly clamping the outer piezoelectric ring 4. Adding a plurality of arc-shaped plates 103 can enhance the radial preload between the outer piezoelectric ring 4, the annular mass block 3, the inner piezoelectric ring 2, and the central column 102 after the tightening ring 5 is assembled.

[0028] Furthermore, the shrinkage gap 104 is disposed between the radial extension lines of adjacent inner tightening grooves 301 and outer tightening grooves 302. That is, a shrinkage gap 104 is provided between the radial extension lines of two adjacent inner tightening grooves 301 and outer tightening grooves 302, realizing a uniform distribution of the inner tightening grooves 301, shrinkage gap 104, and outer tightening grooves 302 in the circumferential direction, thereby achieving more uniform deformation shrinkage. Furthermore, the shrinkage ring, arc plate 103, outer piezoelectric ring 4, annular mass block 3, inner piezoelectric ring 2, and central shaft are all coaxially arranged, and good coaxiality ensures the reliability of the above structure during installation.

[0029] As an embodiment of this utility model, a connector mounting hole 106 is provided in the base 101, a connector assembly 7 is provided in the connector mounting hole 106, and a cable 8 is provided between the connector assembly 7 and the annular mass block 3 for connection. The connector assembly 7 is used to provide a protected path to transmit the weak charge or high impedance voltage signal generated inside the piezoelectric sensor to an external device.

[0030] Correspondingly, such as Figure 3 As shown, there are wiring gaps 6 between the bottom surfaces of the tightening ring 5, the outer piezoelectric ring 4, the annular mass block 3, and the inner piezoelectric ring 2 and the top surface of the base 101. These wiring gaps 6 are used to accommodate the cable 8. Furthermore, the tightening ring 5, the outer piezoelectric ring 4, the annular mass block 3, and the inner piezoelectric ring 2 may have the same axial height and flush bottom surfaces.

[0031] like Figure 8 As shown, a wiring channel 105 is provided in the base 101, the wiring channel 105 connects to the wiring gap 6, and the cable 8 is disposed in the wiring channel 105 and the wiring gap 6.

[0032] Specifically, the connector assembly 7 includes a connector housing 701, within which a conductive core 702 and an insulating layer 703 are sequentially arranged from the inside out. The cable 8 connects the annular mass block 3 and the conductive core 702. The connector assembly 7 extends from the side of the base 101 to facilitate connection with external devices, such as a vibration sensor. The cable 8 conducts the charge generated by the inner piezoelectric ring 2 and the outer piezoelectric ring 4 through the annular mass block 3 to the conductive core 702, and finally to the external device through the external cable 8.

[0033] In one embodiment of this utility model, an upper cover 9 is provided on the base 1. The upper cover 9 and the base 1 cooperate to form an accommodating space. The central column 102, inner piezoelectric ring 2, annular mass block 3, outer piezoelectric ring 4, arc plate 103, and tightening ring 5 are all disposed within this accommodating space. The upper cover 9 protects its internal components while improving the airtightness and electromagnetic shielding performance of the ring shear piezoelectric sensor. A fixing hole 107 is provided on the side of the base 101 away from the upper cover 9. The fixing hole 107 is used to fix the base 101 with external fasteners.

[0034] The high-rigidity ring shear piezoelectric sensor provided by this utility model has grooved structures on the inner piezoelectric ring 2, the annular mass block 3, and the outer piezoelectric ring 4 to obtain deformation tightening space. Several arc-shaped plates 103 are added between the tightening ring 5 and the outer piezoelectric ring 4 to form a contraction gap 104, which enhances the lateral tightening force and makes the connection of the inner piezoelectric ring 2, the annular mass block 3, and the outer piezoelectric ring 4 more compact, thereby improving the lateral stiffness of the ring shear piezoelectric sensor and increasing the resonant frequency of the ring shear piezoelectric sensor.

[0035] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0036] The detailed descriptions listed above are merely specific descriptions of feasible implementation methods of this utility model, and are not intended to limit the scope of protection of this utility model. All equivalent implementation methods or modifications made without departing from the spirit of this utility model should be included within the scope of protection of this utility model.

Claims

1. A high-stiffness ring shear piezoelectric sensor, characterized in that: The base (1) includes a base (101) and a central column (102). The central column (102) is coaxially arranged with the base (101) and extends axially from the end face of the base (101). An inner piezoelectric ring (2), an annular mass block (3), an outer piezoelectric ring (4) and a tightening ring (5) are sequentially arranged from the inside to the outside with the central column (102) as the center. A plurality of tightening grooves are provided on the annular mass block (3). The tightening grooves extend radially from the inner ring or the outer ring of the annular mass block (3). The tightening grooves are blind grooves.

2. The high-stiffness ring shear piezoelectric sensor according to claim 1, characterized in that: The tightening groove includes an inner tightening groove (301) and an outer tightening groove (302). The inner tightening groove (301) extends radially from the inner ring of the annular mass block (3), and the outer tightening groove (302) extends radially from the outer ring of the annular mass block (3). A plurality of the inner tightening grooves (301) are evenly distributed along the circumference of the inner ring of the annular mass block (3), and a plurality of the outer tightening grooves (302) are evenly distributed along the circumference of the outer ring of the annular mass block (3).

3. The high-stiffness ring shear piezoelectric sensor according to claim 2, characterized in that: The inner tightening groove (301) and the outer tightening groove (302) are arranged alternately at intervals.

4. The high-stiffness ring shear piezoelectric sensor according to claim 2, characterized in that: Both the inner tightening groove (301) and the outer tightening groove (302) are straight grooves.

5. The high-stiffness ring shear piezoelectric sensor according to claim 1, characterized in that: A first through groove (303) is provided on the annular mass block (3), and the first through groove (303) penetrates the annular mass block (3) in both the radial and axial directions. A second through groove (201) is provided on the inner piezoelectric ring (2), and the second through groove (201) penetrates the inner piezoelectric ring (2) in both the radial and axial directions. A third through groove (401) is provided on the outer piezoelectric ring (4), and the third through groove (401) penetrates the outer piezoelectric ring (4) in both the radial and axial directions.

6. The high-stiffness ring shear piezoelectric sensor according to claim 2, characterized in that: A plurality of arc-shaped plates (103) are also provided on the base (101). The plurality of arc-shaped plates (103) are evenly distributed around the central column (102) in the circumferential direction. The plurality of arc-shaped plates (103) are coaxial with the central column (102). A shrinkage gap (104) is formed between adjacent arc-shaped plates (103). The arc-shaped plates (103) are disposed between the tightening ring (5) and the outer piezoelectric ring (4).

7. The high-stiffness ring shear piezoelectric sensor according to claim 6, characterized in that: The contraction gap (104) is provided between adjacent inner tightening grooves (301) and outer tightening grooves (302).

8. The high-stiffness ring shear piezoelectric sensor according to claim 1, characterized in that: A connector assembly (7) is provided inside the base (101), and a cable (8) is provided between the connector assembly (7) and the annular mass block (3) for connection.

9. The high-stiffness ring shear piezoelectric sensor according to claim 8, characterized in that: There are wiring gaps (6) between the bottom surface of the tightening ring (5), the bottom surface of the outer piezoelectric ring (4), the bottom surface of the annular mass block (3) and the bottom surface of the inner piezoelectric ring (2) and the top surface of the base (101). A wiring channel (105) is provided in the base (101), and the wiring channel (105) connects the wiring gap (6). The cable (8) is located in the wiring channel (105) and the wiring gap (6).

10. The high-stiffness ring shear piezoelectric sensor according to claim 1, characterized in that: A top cover (9) is provided on the base (1), and the top cover (9) and the base (1) cooperate to form an accommodating space. The central column (102), inner piezoelectric ring (2), annular mass block (3), outer piezoelectric ring (4), and tightening ring (5) are all arranged in the accommodating space. A fixing hole (107) is provided on the base (101).

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