Shear type piezoelectric sensor
By designing ring -shaped piezoelectric components, central shaft rods, quality blocks and electrodes in the shear voltage sensor, use the rotation movement of the quality block to generate the potential difference, solving the shear voltage sensor. The problem of large -scale exertion achieves the sensing effect of small volume and high sensitivity.
Patent Information
- Application Number
- CN202311018484.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-07-26
- Filing Date
- 2023-08-14
- Publication Date
- 2025-01-28
AI Technical Summary
Shear piezoelectric sensors require a large force to drive the piezoelectric components, resulting in an increase in the overall volume of the product, an increase in cost, and limited application.
Design a shear piezoelectric sensor, through the combination of ringgtzer components, central shaft rods, quality blocks, first electrodes, and second electrodes. Exercise causes variables and causes potential differences.
Eraded the power of the quality block through the concept of torque, thereby increasing the shear power of the circular piezoelectric component, realizing the function of the small volume quality block driving the piezoelectric component, reducing the overall volume and cost, expanding the application range, and increasing Testing sensitivity.
Smart Images
Figure CN119374637A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a sensor, in particular to a shear-type piezoelectric sensor. Background Art
[0002] Currently, piezoelectric sensors can be used to sense force, pressure, tension, acceleration, etc., and their measurement principles can be mainly divided into compression, bending and shear. Among them, the shear type has the best characteristics, mainly because the piezoelectric characteristics of piezoelectric elements in the shear direction are usually higher than in other directions. Therefore, most of the current high-specification piezoelectric sensors use the shear type. However, shear pressure sensors require a larger force (compared to compression pressure sensors and bending pressure sensors) to drive the piezoelectric element (that is, the piezoelectric element generates power). Therefore, the shear piezoelectric sensors currently developed by international manufacturers use a mass block volume that is more than dozens of times larger than the volume of the piezoelectric element, which will increase the overall volume of the product, increase costs, and limit applications. Summary of the invention
[0003] In view of the above, a shear-type piezoelectric sensor is provided, comprising an annular piezoelectric element, a central shaft, a mass block, a first electrode and a second electrode. The annular piezoelectric element comprises an outer annular wall and an inner annular wall. The central shaft is made of a conductive material, and the central shaft is fixed to the inner annular wall of the annular piezoelectric element through penetration. The mass block is made of a conductive material, and the mass block comprises a fixing member and a counterweight member, the fixing member comprises a fixing hole, the fixing member is fixed to the outer annular wall of the annular piezoelectric element by sleeve-mounting the fixing hole, and the counterweight member is arranged on an opposite side of the fixing member away from the fixing hole. The first electrode is electrically connected to the central shaft. The second electrode is electrically connected to the mass block. The counterweight member of the mass block rotates relative to the central shaft, causing the annular piezoelectric element to deform and generating a potential difference between the first electrode and the second electrode.
[0004] In some embodiments, the shear-type piezoelectric sensor further includes a body, the body is provided with a receiving groove, and the annular piezoelectric element, the central shaft and the mass block are received in the receiving groove.
[0005] In some embodiments, the receiving groove includes an opening, and the counterweight is exposed outside the opening.
[0006] In some embodiments, the fixing member is provided with a notch, and the notch is located on a side opposite to the counterweight member.
[0007] In some embodiments, the main body is provided with a retaining wall, the retaining wall is located at the bottom surface of the receiving groove, and the counterweight is located above the retaining wall.
[0008] In some embodiments, the fixing element and the weight element are made of different materials, and the fixing element is made of a conductive material.
[0009] In some embodiments, the counterweight member extends radially outward from the fixing member along the central shaft.
[0010] In some embodiments, the shear-type piezoelectric sensor further includes a processing unit, which is respectively connected to the first electrode and the second electrode, and generates a corresponding acceleration value according to the potential difference.
[0011] In some embodiments, the body is made of insulating material.
[0012] In some embodiments, the piezoelectric element is circular or C-shaped. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 A three-dimensional and partial perspective diagram of a shear-type piezoelectric sensor is shown in some embodiments;
[0014] Figure 2 In some embodiments, Figure 1 Schematic diagram of the cross section of AA;
[0015] Figure 3 FIG. 1 is an exploded schematic diagram of a shear-type piezoelectric sensor in some embodiments;
[0016] Figure 4 A three-dimensional schematic diagram of a shear-type piezoelectric sensor is shown in some embodiments;
[0017] Figure 5 In some embodiments, Figure 4 Schematic cross-section of the middle BB;
[0018] Figure 6 A three-dimensional schematic diagram of a shear-type piezoelectric sensor is shown in some embodiments;
[0019] Figure 7 A schematic cross-sectional view of a shear-type piezoelectric sensor is shown in some embodiments;
[0020] Figure 8 Graphs showing experimental data of shear-type piezoelectric sensors in some embodiments;
[0021] Fig. 9 Graphs showing experimental data of shear-type piezoelectric sensors in some embodiments.
[0022]
Explanation of symbols
[0023] AA: Section Line
[0024] BB: Cutting line
[0025] F: Force
[0026] P: Center of gravity
[0027] d: Spacing
[0028] R: Region
[0029] 10: Ring piezoelectric element
[0030] 11: Outer ring wall
[0031] 12: Inner ring wall
[0032] 20: Central axis
[0033] 30: Mass block
[0034] 31:Fixer
[0035] 311:Fixing hole
[0036] 312: Slot
[0037] 32: Counterweight
[0038] 40: first electrode
[0039] 50: Second electrode
[0040] 60:Ontology
[0041] 61: Receiving groove
[0042] 611: Left and right side walls
[0043] 612: Inner wall
[0044] 613: Opening
[0045] 62: Resist the Wall
[0046] 70: Processing unit DETAILED DESCRIPTION
[0047] See also Figure 1 As shown, in some embodiments, the shear piezoelectric sensor can be used to sense force, pressure, tension, acceleration, etc. The shear piezoelectric sensor includes an annular piezoelectric element 10 , a central shaft 20 , a mass block 30 , a first electrode 40 and a second electrode 50 .
[0048] See also Figure 1 , Figure 2 and Figure 3 As shown, the annular piezoelectric element 10 includes an outer annular wall 11 and an inner annular wall 12. Figure 2 , Figure 3 As shown, in some embodiments, the annular piezoelectric element 10 is circular. Figure 5As shown, in some embodiments, the annular piezoelectric element 10 has a notch to form a C-shape. In some embodiments, the annular piezoelectric element 10 forms a semicircular shape or an arc shape according to the size of the notch.
[0049] See also Figure 1 , Figure 2 and Figure 3 As shown, the central shaft 20 is made of a conductive material (such as copper metal), and the central shaft 20 is fixed to the inner ring wall 12 of the annular piezoelectric element 10, that is, the annular piezoelectric element 10 is located on the ring side of the central shaft 20. In some embodiments, the central shaft 20 is horizontally placed and parallel to the horizontal plane.
[0050] See also Figure 1 , Figure 2 and Figure 3 As shown, the mass block 30 is made of a conductive material (such as copper metal). The mass block 30 includes a fixing member 31 and a counterweight 32. The fixing member 31 includes a fixing hole 311. The fixing member 31 is fixed on the outer ring wall 11 of the annular piezoelectric element 10 by means of the fixing hole 311, that is, the fixing member 31 is located on the surface of the outer ring wall 11, so that the annular piezoelectric element 10 is located between the fixing member 31 and the central shaft 20. The counterweight 32 is disposed on the fixing member 31 and on an opposite side away from the fixing hole 311, so that the center of gravity P of the mass block 30 will be away from the central shaft 20, thereby increasing the length of the center of gravity P to the annular piezoelectric element 10. In some embodiments, the annular piezoelectric element 10 is arc-shaped, and the hole wall of the fixing hole 311 is recessed inward to form an arc-shaped groove. The annular piezoelectric element 10 is disposed in the arc-shaped groove, and one side of the annular piezoelectric element 10 is connected to the central shaft 20.
[0051] See also Figure 1 , Figure 2 and Figure 3 As shown, the second electrode 50 is electrically connected to the central shaft 20. In some embodiments, the second electrode 50 is a wire.
[0052] See also Figure 1 , Figure 2 and Figure 3 As shown, the first electrode 40 is electrically connected to the mass 30. In some embodiments, the first electrode 40 is a wire. Therefore, the first electrode 40, the second electrode 50, the central shaft 20, the annular piezoelectric element 10, and the mass 30 can form a conductive loop together, and the first electrode 40 and the second electrode 50 form a positive electrode and a negative electrode respectively, for conducting the power generated by the annular piezoelectric element 10.
[0053] See also Figure 1 , Figure 2 and Figure 3As shown, when the counterweight 32 is subjected to a force F (such as inertial force, pressure, tension) from top to bottom, a force arm is formed from the center of gravity P to the central shaft 20, and a shear force is formed on the annular piezoelectric element 10, so that the annular piezoelectric element 10 is deformed and generates power. Since the first electrode 40, the second electrode 50, the central shaft 20, the annular piezoelectric element 10, and the mass 30 together form a conductive loop, a potential difference is generated between the first electrode 40 and the second electrode 50.
[0054] This case uses the concept of torque to amplify the force F applied to the mass block 30, thereby increasing the shear force of the annular piezoelectric element 10. Therefore, this case uses a small-volume mass block 30 to deform the annular piezoelectric element 10, thereby driving the shear-type piezoelectric sensor to work. Therefore, the shear-type piezoelectric sensor of this case has the advantages of reducing the overall volume, reducing costs, and increasing the scope of application. In addition, the farther the center of gravity P is from the central shaft 20, the longer the force arm between the center of gravity P and the central shaft 20 is, thereby increasing the shear force applied to the annular piezoelectric element 10, thereby improving the detection sensitivity of the shear-type piezoelectric sensor of this case.
[0055] See also Figure 1 , Figure 2 ,and Figure 3 As shown, the shear-type piezoelectric sensor further includes a body 60. The body 60 is provided with a receiving groove 61, and the annular piezoelectric element 10, the central shaft 20 and the mass block 30 are received in the receiving groove 61. In some embodiments, the receiving groove 61 is provided in the body 60 to form left and right side walls 611 and an inner side wall 612, and the central shaft 20 is provided between the left and right side walls 611 to form a horizontal state, so that the shear-type piezoelectric sensor is used to detect the applied force F in the Z-axis direction. In some embodiments, the body 60 is made of an insulating material (such as plastic) to prevent the body 60 from forming a short circuit with other components. In some embodiments, the mass block 30 and the body 60 have a spacing d to prevent the mass block 30 from contacting the body 60.
[0056] See also Figure 1 , Figure 2 ,and Figure 3 As shown, in some embodiments, the receiving groove 61 includes an opening 613, and the counterweight 32 is exposed outside the opening 613. The counterweight 32 can be exposed outside the opening 613 as a whole or partially outside the opening 613, so as to make the center of gravity P of the mass block 30 further away from the central shaft 20.
[0057] See also Figure 2 and Figure 3As shown, in some embodiments, the fixing member 31 is provided with a notch portion 312, and the notch portion 312 is located on the side opposite to the counterweight member 32, that is, the notch portion 312 is located on the side of the fixing member 31 facing the inner wall 612. In this way, the center of gravity P of the mass block 30 will deviate from the central shaft 20 to increase the length of the force arm A, so as to enhance the detection sensitivity of the shear-type piezoelectric sensor. The notch portion 312 can be formed by the fixing member 31 being recessed inwardly, or the fixing member 31 can be formed by a ring wall on the outside, and a part of the ring wall is cut to form the notch portion 312.
[0058] See also Figure 4 and Figure 5 As shown, in some embodiments, the opening 613 of the receiving groove 61 extends from one side of the body 60 to the bottom surface of the body 60. Figure 1 and Figure 3 As shown, in some embodiments, the body 60 is provided with a blocking wall 62 , the blocking wall 62 is located at the bottom surface of the receiving groove 61 , and the counterweight 32 is against the blocking wall 62 .
[0059] See also Figure 6 and Figure 7 As shown, in some embodiments, the fixing member 31 and the counterweight member 32 are made of different materials, and the fixing member 31 is made of a conductive material. For example, but not limited to, the fixing member 31 is made of copper and the counterweight member 32 is made of iron. In addition, the counterweight member 32 may be in the shape of a cylinder, such as a cylinder, a semi-cylinder, or a polygonal cylinder, and is vertically disposed on one side of the fixing member 31, and the counterweight member 32 is partially or completely exposed outside the opening 613. In addition, please refer to Figure 1 As shown, in some embodiments, the fixing member 31 and the weight member 32 are integrally formed, that is, the weight member 32 extends outward from the fixing member 31 along the radial direction of the central shaft 20. In this way, the center of gravity P of the mass block 30 will be greatly deviated from the central shaft 20 to enhance the detection sensitivity of the shear piezoelectric sensor.
[0060] See also Figure 1 As shown, the shear piezoelectric sensor further includes a processing unit 70, which is connected to the first electrode 40 and the second electrode 50 respectively. The processing unit 70 generates a corresponding acceleration value according to the potential difference. In some embodiments, the processing unit 70 can generate a corresponding acceleration value according to the potential difference and the formula: The acceleration value is obtained, wherein a is the acceleration value, s is the sensitivity value, Δv is the potential difference, and the sensitivity value is a preset value. Each potential difference and the corresponding acceleration value may also be calculated in advance and stored in a database, and the processing unit 70 finds the corresponding acceleration value in the database according to the potential difference. In some embodiments, the processing unit 70 may also obtain the force F value according to the potential difference, and the method of obtaining the force F may also be to calculate the relationship between each potential difference and the force F in advance and store it in the database, and the processing unit 70 finds the corresponding force F in the database according to the potential difference. In addition, in some embodiments, the setting of the sensitivity value is to use an oscillator to generate acceleration for the shear piezoelectric sensor, and then pull out two signal lines from the first electrode 40 and the second electrode 50 at different phase angles, connect the signal lines to a charge and voltage converter (for example, 1pC to 1mV), and then use the capture card to convert the analog signals transmitted by the two signal lines into digital signals, and finally transmit them to the computer through the USB interface, using a variation of the above formula: The sensitivity value is obtained as a preset sensitivity value.
[0061] In addition, although the shear type piezoelectric sensor is described above as being used to detect the force F in the Z-axis direction, the shear type piezoelectric sensor can be used to detect the force F in the X-axis direction and the Y-axis direction according to the setting posture. In addition, in some embodiments, the fixing hole 311 of the fixing member 31 and the outer ring wall 11 of the annular piezoelectric element 10, and the inner ring wall 12 of the annular piezoelectric element 10 and the central shaft 20 are connected by an adhesive.
[0062] See also Figure 8 As shown, the shear type piezoelectric sensor of this case is simulated and tested for structure and characteristics using Ansys software. The test conditions are that the material of the annular piezoelectric element 10 is lead zirconate titanate, and its density is 7700kg / m 3 , Young's modulus is 6E+10Pa, Poisson's ratio is 0.34, bulk modulus is 6.25E+10Pa, shear modulus is 2.2388E+10Pa, the material of the mass block 30 and the body 60 is stainless steel, and its density is 7750kg / m 3 , Young's modulus is 1.93E+10Pa, Poisson's ratio is 0.31, bulk modulus is 1.693E+11Pa, and shear modulus is 7.3664E+10Pa. Figure 8It is shown that under the above conditions, a resonance frequency of about 19kHz can be obtained. Therefore, the shear piezoelectric sensor in this case can increase the overall resonance frequency, thereby increasing the overall available bandwidth. Fig. 9 As shown, the stress analysis of various parts of the shear-type piezoelectric sensor in this case during use is analyzed using Ansys software. The analysis results show that the area R located on the inner ring wall 12 of the annular piezoelectric element 10 is subjected to the greatest stress (about 1.1104e-8MPa to 9.7129e-8MPa), which is also the position where the shear-type piezoelectric sensor produces the maximum deformation.
Claims
1. A shear-type piezoelectric sensor, characterized in that: include: An annular piezoelectric element, comprising an outer annular wall and an inner annular wall; A central shaft, made of a conductive material, the central shaft passing through the inner ring wall of the annular piezoelectric element and fixed thereto; A mass block is made of a conductive material, the mass block includes a fixing member and a counterweight member, the fixing member includes a fixing hole, the fixing member is fixed to the outer ring wall of the annular piezoelectric element by sleeve-mounting the fixing hole, and the counterweight member is arranged on an opposite side of the fixing member away from the fixing hole; a first electrode electrically connected to the central shaft; and a second electrode electrically connected to the mass block; The counterweight of the mass block rotates relative to the central shaft, causing the annular piezoelectric element to deform and generating a potential difference between the first electrode and the second electrode.
2. The shear-type piezoelectric sensor according to claim 1, wherein: It also includes a main body, which is provided with a containing groove, and the annular piezoelectric element, the central shaft and the mass block are contained in the containing groove.
3. The shear-type piezoelectric sensor according to claim 2, wherein: The accommodating groove includes an opening, and the counterweight is exposed outside the opening.
4. The shear-type piezoelectric sensor according to claim 2, wherein: The main body is provided with a resisting wall, the resisting wall is located on the bottom surface of the accommodating groove, and the counterweight piece is against the resisting wall.
5. The shear-type piezoelectric sensor according to claim 2, wherein: The body is made of insulating material.
6. The shear-type piezoelectric sensor according to claim 1, wherein: The fixing member is provided with a notch portion, and the notch portion is located on a side opposite to the counterweight member.
7. The shear-type piezoelectric sensor according to claim 1, wherein: The fixing member and the counterweight member are made of different materials, and the fixing member is made of a conductive material.
8. The shear-type piezoelectric sensor according to claim 1, wherein: The counterweight member extends outward from the fixing member along the radial direction of the central shaft.
9. The shear-type piezoelectric sensor according to claim 1, wherein: The device further comprises a processing unit, which is connected to the first electrode and the second electrode respectively, and generates a corresponding acceleration value according to the potential difference.
10. The shear-type piezoelectric sensor according to claim 1, wherein: The annular piezoelectric element is circular or C-shaped.