High-sensitivity piezoelectric vibration sensor

Abstract

The invention belongs to the field of vibration sensors, and provides a high-sensitivity piezoelectric vibration sensor, which comprises a shell, one end of the shell is provided with a fixing structure, the other end of the shell is provided with a mounting cavity, the interior of the mounting cavity is rotatably connected with a positioning column, the outer side of the positioning column is sleeved with an annular piezoelectric ceramic piece, and the annular piezoelectric ceramic piece is connected with the mounting cavity. One end of the positioning column is fixedly connected with a pre-tightening screw rod, and the pre-tightening screw rod is sleeved with a universal mass block assembly. When the pretightening force of the universal mass block assembly on the annular piezoelectric ceramic piece is adjusted, the push pipe is pushed to enable the extrusion pipe to leave the side face of the elastic ring piece and the middle of the elastic ring piece to bulge, so that the limitation of the outer teeth on the adjusting head is relieved, the adjusting head can be rotated at the moment, the adjusting head drives the pretightening screw to rotate, and the pretightening force of the annular piezoelectric ceramic piece is adjusted. The pre-tightening force of the pre-tightening nut can be adjusted by hands without using tools, and the device is more convenient to adjust the pre-tightening force and simpler to operate.

Description

Technical Field

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

[0002] Industrial equipment generally has different degrees of vibration during operation. Severe vibration will reduce the efficiency of the equipment and the accuracy of the actuator, damage the operating state of the machine, and even shorten the service life of the equipment. Therefore, it is necessary to detect relevant vibration information. At present, the acquisition of vibration detection information is mainly achieved through vibration sensors. Vibration sensors mainly include piezoelectric, piezoresistive, and piezoceramic, among which piezoelectric vibration sensors are the most common.

[0003] A piezoelectric vibration sensor is a sensor that measures vibration signals through the positive piezoelectric effect. When the sensor is subjected to external force, electric charges will accumulate on the surfaces of the two electrodes. The amount of charge is positively correlated with the magnitude of the external force applied to the sensor.

[0004] Piezoelectric vibration sensors are usually composed of a pre-tightening screw, a pre-tightening bolt, a mass block, a piezoelectric sensitive element, and a housing. The pre-tightening method of the sensitive element is the pre-tightening between the pre-tightening screw and the pre-tightening bolt. The pre-tightening force of the pre-tightening bolt determines the pre-tightening degree of the piezoelectric sensitive element and the mass block.

[0005] However, with the long-term use of the sensor, the pre-tightening force of the pre-tightening bolt will gradually decrease, causing a gap between the mass block and the piezoelectric sensitive element, resulting in a decrease in the sensitivity of the sensor. At this time, the pre-tightening force of the sensor must be adjusted. Since the pre-tightening bolt is inside the sensor, professional tools are required for adjustment, and its maintenance operation is more troublesome. Summary of the invention

[0006] The purpose of the present invention is to provide a high-sensitivity piezoelectric vibration sensor, aiming to solve the technical problem in the prior art that professional tools are needed to adjust the preload force, resulting in troublesome maintenance operations.

[0007] The present invention is implemented as follows: a highly sensitive piezoelectric vibration sensor comprises a shell, one end of which is provided with a fixing structure, and the device can be installed on an object to be measured through the fixing structure; the other end of the shell is provided with an installation cavity, the interior of the installation cavity is rotatably connected with a positioning column, the outer side of the positioning column is sleeved with an annular piezoelectric ceramic sheet, one end of the positioning column is fixedly connected with a pre-tightening screw, a Vientiane mass block assembly is sleeved on the pre-tightening screw, the side of the Vientiane mass block assembly is in contact with the side of the annular piezoelectric ceramic sheet, a pre-tightening nut is also threadedly connected to the pre-tightening screw, and the pre-tightening nut and the Vientiane mass block assembly are in contact with each other. The pre-tightening nut is slidably connected to the inside of the nut frame, and the nut frame is used to prevent the pre-tightening nut from rotating relative to the shell. The end of the shell is rotatably connected to the pre-tightening mechanism, and one end of the pre-tightening screw is fixedly connected to the side of the pre-tightening mechanism. A circuit board is arranged between the nut frame and the pre-tightening mechanism, and the positive and negative poles of the circuit board are electrically connected to the positive and negative poles of the annular piezoelectric ceramic piece through wires. A wiring groove is provided on the side of the pre-tightening mechanism away from the shell, and a terminal is arranged inside the wiring groove, and the circuit board is electrically connected to the terminal through a wire.

[0008] Further technical solution: the fixing structure is a connecting head, and the connecting head is a stud.

[0009] Further technical solution: the nut frame includes a plurality of limit guide blocks fixedly connected to the inner wall of the installation cavity, the plurality of limit guide blocks are slidably connected to a connecting frame, the plurality of connecting frames are fixedly connected to the same limit frame, the limit frame is provided with a nut hole adapted for the pre-tightening nut, and the pre-tightening nut is slidably connected in the nut hole.

[0010] Further technical solution: the pre-tightening mechanism includes an adjusting head rotatably connected to one end of the shell, one end of the pre-tightening screw is fixedly connected to the side of the adjusting head, the adjusting head is fixedly connected to the side of the shell close to the limiting sleeve, and the limiting sleeve is sleeved on one end of the shell; In order to ensure that the adjusting head can be relatively fixed to the shell, a self-locking mechanism is provided between the limiting sleeve and the shell.

[0011] Further technical solution: the self-locking mechanism includes an elastic ring sheet, which is arranged on a limiting sleeve, and the elastic ring sheet is made of elastic metal. Initially, the middle part of the side wall of the elastic ring sheet protrudes outward, and the inner side wall of the elastic ring sheet is provided with a plurality of external teeth, and the plurality of external teeth are evenly distributed around the axis of the elastic ring sheet. An inner tooth ring is embedded in the side surface of the shell, and the outer side surface of the inner tooth ring is provided with a plurality of internal teeth, and the plurality of internal teeth are evenly distributed around the axis of the shell, and the plurality of internal tooth rings are respectively engaged with the plurality of internal teeth; In order to facilitate the rotation of the adjustment head, a plurality of the outer teeth are made of elastic material, and the outer teeth can be deformed with the deformation of the elastic ring piece. When the middle part of the side wall of the elastic ring piece protrudes outward, the inner tooth ring and the inner teeth are away from each other, and the ends of the outer teeth are in contact with the ends of the inner teeth. The deformation coefficient of the ends of the outer teeth is large. When the adjustment head drives the outer teeth to rotate, the inner teeth can push the outer teeth to deform, so that the inner teeth continue to move over the outer teeth, thereby realizing the rotation of the adjustment head; In order to facilitate the inner gear ring to prevent the outer teeth from moving, the cross-sections of the outer teeth and the inner teeth are both triangular. When the elastic ring drives the outer teeth to approach the inner gear ring, the outer teeth are inserted between the inner teeth, and the ends of the inner teeth are in contact with the roots of the outer teeth. Since the roots of the outer teeth are thicker and the deformation coefficient is small, the inner teeth cannot move the roots of the outer teeth to deform, so that the inner teeth can prevent the outer teeth and the adjustment head from rotating. In order to fix the limiting sleeve, the self-locking mechanism also includes a locking mechanism, which is slidably installed on the shell, and the output end of the locking mechanism is sleeved on one end of the limiting sleeve. The locking mechanism is used to squeeze the raised part of the elastic ring piece flat, so that the elastic ring piece drives the outer teeth to insert between the inner teeth, and then fix the limiting sleeve and the adjusting head on the shell.

[0012] Further technical solution: the locking mechanism comprises a push tube sleeved on the shell, a first slide groove is provided on the side of the shell, a first slider is fixedly connected to the inner side wall of the push tube, the first slider is slidably connected in the first slide groove, an extrusion tube is fixedly connected to the end side of the push tube, the extrusion tube is sleeved on one end of the limiting sleeve, and the inner diameter of the extrusion tube is the same as the outer diameter of the limiting sleeve; In order to facilitate pushing the push tube, the outer side surface of the push tube is provided with anti-slip grooves; After the extrusion tube squeezes the elastic ring sheet flat, in order to prevent the extrusion tube from slipping off the limiting sleeve again, a compression spring is arranged between the first sliding block and the side wall of the first sliding groove away from the limiting sleeve.

[0013] Further technical solution: The Vientiane mass block assembly includes a vertical mass block, which is sleeved on the preload screw. One end of the vertical mass block is in contact with the annular piezoelectric ceramic sheet. The other end of the vertical mass block is provided with a cross bevel groove. The four ends of the cross bevel groove are all inclined surfaces. The angle between the inclined surface and the horizontal plane is 45°. A horizontal cross mass block is arranged inside the cross bevel groove. The shape of the horizontal cross mass block matches the shape of the cross bevel groove. The horizontal cross mass block is provided with a movable hole for the preload screw to pass through. The diameter of the movable hole is larger than the diameter of the preload screw.

[0014] Further technical solution: an upper electrode sheet is arranged on the top of the annular piezoelectric ceramic sheet, an upper insulating sheet is arranged between the upper electrode sheet and the shell, a lower electrode sheet is arranged on the bottom of the annular piezoelectric ceramic sheet, a lower insulating sheet is arranged between the lower electrode sheet and the universal mass block assembly, and the upper electrode sheet and the lower electrode sheet are respectively connected to the positive and negative poles of the circuit board through wires.

[0015] Further technical solution: a gasket is arranged between the pre-tightening nut and the universal mass block assembly.

[0016] Further technical solution: an upper pad and a lower pad are respectively provided on both sides of the circuit board.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, when adjusting the pre-tightening force of the universal mass block assembly on the annular piezoelectric ceramic sheet, the push tube is pushed to make the extrusion tube leave the side of the elastic ring sheet, and the middle part of the elastic ring sheet bulges, thereby releasing the restriction of the external teeth on the adjustment head. At this time, the adjustment head can be rotated, and the adjustment head drives the pre-tightening screw to rotate, and then the pre-tightening force of the pre-tightening nut can be adjusted. No tools are needed, and the adjustment can be performed by hand. The device is more convenient to adjust the pre-tightening force and simpler to operate. 2. In the present invention, after the pre-tightening force of the pre-tightening nut is adjusted, the push tube is pushed to drive the extrusion tube to extrude the elastic ring sheet, the elastic ring sheet is squeezed flat, and the elastic ring sheet drives the outer teeth to be inserted between the inner teeth, and then the adjustment head is fixed to prevent the pre-tightening screw from rotating, thereby preventing the pre-tightening nut from loosening; 3. In the present invention, by setting a vertical mass block and a horizontal cross mass block, when the object to be measured vibrates along the axial direction of the shell, the vertical mass block and the horizontal cross mass block squeeze the annular piezoelectric ceramic piece; when the object to be measured vibrates perpendicular to the axial direction of the shell, the object to be measured will drive the horizontal cross mass block to squeeze the inclined surface of the vertical mass block. The force of the horizontal cross mass block will produce components in both the horizontal and vertical directions, and the component along the axial direction of the shell will be detected by the annular piezoelectric ceramic piece. Therefore, the device can detect the vibration of the object to be measured in any direction, and the sensitivity of the device is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall front view structure of the present invention.

[0019] Figure 2 It is a schematic diagram of the overall structure of the present invention when viewed from above.

[0020] Figure 3 It is a schematic diagram of the overall cross-sectional internal structure of the present invention.

[0021] Figure 4 For the present invention Figure 3 Enlarged schematic diagram at point A in the middle.

[0022] Figure 5 It is a schematic diagram of the overall internal structure of the present invention.

[0023] Figure 6 It is a schematic structural diagram of the initial pre-tightening mechanism in the present invention.

[0024] Figure 7 It is a schematic diagram of the structure of the elastic ring sheet in the present invention.

[0025] Figure 8 It is a schematic diagram of the installation structure of the universal mass block assembly and the pre-tightening nut in the present invention.

[0026] Fig. 9 It is a schematic diagram of the cross-sectional structure of the universal mass block assembly in the present invention.

[0027] Fig.10 It is a schematic diagram of the structure of the vertical mass block in the present invention.

[0028] In the accompanying drawings: 1. Connector; 2. Shell; 3. Locking mechanism; 31. Compression spring; 32. First slide groove; 33. Push tube; 34. First slider; 35. Extrusion tube; 4. Pre-tightening mechanism; 41. Inner gear ring; 42. Outer teeth; 43. Elastic ring; 44. Limit sleeve; 45. Adjusting head; 5. Wiring groove; 6. Terminal; 7. Annular piezoelectric ceramic; 8. Universal mass block assembly; 81. Horizontal cross mass block; 82. Vertical mass block; 83. Cross bevel groove; 9. Nut rack; 91. Connecting rack; 92. Limiting guide block; 93. Limiting rack; 10. Circuit board; 11. Upper insulating sheet; 12. Upper electrode sheet; 13. Lower electrode sheet; 14. Lower insulating sheet; 15. Gasket; 16. Upper pad; 17. Lower pad; 18. Pre-tightening nut; 19. Pre-tightening screw; 20. Positioning column. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0031] like Figure 1-Figure 10As shown, a highly sensitive piezoelectric vibration sensor provided by the present invention comprises a shell 2, one end of the shell 2 is provided with a fixing structure, and the device can be installed on the object to be measured through the fixing structure, and the other end of the shell 2 is provided with an installation cavity, and a positioning column 20 is rotatably connected inside the installation cavity, and an annular piezoelectric ceramic sheet 7 is sleeved on the outer side of the positioning column 20, and a pre-tightening screw 19 is fixedly connected to one end of the positioning column 20, and a universal mass block assembly 8 is sleeved on the pre-tightening screw 19, and the side of the universal mass block assembly 8 contacts the side of the annular piezoelectric ceramic sheet 7, and a pre-tightening nut 18 is also threadedly connected to the pre-tightening screw 19, and the pre-tightening nut 18 and the universal mass block assembly 8 are in contact with each other. The block assembly 8 abuts, and a nut rack 9 is slidably connected to the inside of the installation cavity. The pre-tightening nut 18 is slidably connected to the inside of the nut rack 9. The nut rack 9 is used to prevent the pre-tightening nut 18 from rotating relative to the shell 2. The end of the shell 2 is rotatably connected to the pre-tightening mechanism 4, and one end of the pre-tightening screw 19 is fixedly connected to the side of the pre-tightening mechanism 4. A circuit board 10 is arranged between the nut rack 9 and the pre-tightening mechanism 4, and the positive and negative poles of the circuit board 10 are electrically connected to the positive and negative poles of the annular piezoelectric ceramic piece 7 through wires. A wiring groove 5 is opened on the side of the pre-tightening mechanism 4 away from the shell 2, and a terminal 6 is arranged inside the wiring groove 5. The circuit board 10 is electrically connected to the terminal 6 through a wire.

[0032] Insert the connecting wire into the wiring slot 5 and fix the connector 1 to the object to be measured, and then start measuring the vibration of the object to be measured.

[0033] like Figure 1 As shown, a high-sensitivity piezoelectric vibration sensor provided by the present invention is shown. In this embodiment, the fixing structure is a connector 1, and the connector 1 is a stud.

[0034] like Figure 3-Figure 5 and Figure 8 As shown, a high-sensitivity piezoelectric vibration sensor provided by the present invention, in this embodiment, the nut frame 9 includes a plurality of limit guide blocks 92 fixedly connected to the inner wall of the installation cavity, and the plurality of limit guide blocks 92 are slidably connected to a connecting frame 91, and the plurality of connecting frames 91 are fixedly connected to the same limit frame 93, and the limit frame 93 is provided with a nut hole adapted to the pre-tightening nut 18, and the pre-tightening nut 18 is slidably connected in the nut hole.

[0035] When the pre-tightening mechanism 4 is rotated, the pre-tightening mechanism 4 drives the pre-tightening screw 19 to rotate. Since the nut frame 9 limits the rotation of the pre-tightening nut 18, the pre-tightening nut 18 can move relative to the pre-tightening screw 19, so that the pre-tightening nut 18 presses against the universal mass block assembly 8, the device.

[0036] like Figure 1-Figure 7As shown, a highly sensitive piezoelectric vibration sensor provided by the present invention is provided. In this embodiment, the pre-tightening mechanism 4 includes an adjusting head 45 rotatably connected to one end of the housing 2, one end of the pre-tightening screw 19 is fixedly connected to the side of the adjusting head 45, and the adjusting head 45 is fixedly connected to a limiting sleeve 44 near the side of the housing 2, and the limiting sleeve 44 is sleeved on one end of the housing 2; In order to ensure that the adjusting head 45 can be relatively fixed to the housing 2 , a self-locking mechanism is provided between the limiting sleeve 44 and the housing 2 .

[0037] like Figure 3-Figure 7 As shown, a highly sensitive piezoelectric vibration sensor provided by the present invention, in this embodiment, the self-locking mechanism includes an elastic ring piece 43, the elastic ring piece 43 is arranged on a limiting sleeve 44, the elastic ring piece 43 is made of elastic metal, initially, the middle part of the side wall of the elastic ring piece 43 protrudes outward, the inner side wall of the elastic ring piece 43 is provided with a plurality of external teeth 42, the plurality of external teeth 42 are evenly distributed around the axis of the elastic ring piece 43, the side surface of the shell 2 is embedded with an internal tooth ring 41, the outer side surface of the internal tooth ring 41 is provided with a plurality of internal teeth, the plurality of internal teeth are evenly distributed around the axis of the shell 2, and the plurality of internal tooth rings 41 are respectively engaged with the plurality of internal teeth; In order to facilitate the rotation of the adjustment head 45, the plurality of outer teeth 42 are made of elastic material, and the outer teeth 42 can be deformed along with the deformation of the elastic ring piece 43. When the middle part of the side wall of the elastic ring piece 43 protrudes outward, the inner tooth ring 41 and the inner teeth are away from each other, and the ends of the outer teeth 42 are in contact with the ends of the inner teeth. The deformation coefficient of the ends of the outer teeth 42 is large. When the adjustment head 45 drives the outer teeth 42 to rotate, the inner teeth can push the outer teeth 42 to deform, so that the inner teeth continue to move over the outer teeth 42, thereby realizing the rotation of the adjustment head 45. In order to facilitate the inner gear ring 41 to prevent the outer teeth 42 from moving, the cross-sections of the outer teeth 42 and the inner teeth are both triangular. When the elastic ring piece 43 drives the outer teeth 42 to approach the inner gear ring 41, the outer teeth 42 are inserted between the inner teeth, and the ends of the inner teeth are in contact with the roots of the outer teeth 42. Since the roots of the outer teeth 42 are thicker and the deformation coefficient is small, the inner teeth cannot move the roots of the outer teeth 42 to deform, so that the inner teeth can prevent the outer teeth 42 and the adjustment head 45 from rotating. In order to achieve the fixation of the limiting sleeve 44, the self-locking mechanism also includes a locking mechanism 3, which is slidably installed on the shell 2, and the output end of the locking mechanism 3 is sleeved on one end of the limiting sleeve 44. The locking mechanism 3 is used to squeeze the raised part of the elastic ring piece 43 flat, so that the elastic ring piece 43 drives the outer teeth 42 to be inserted between the inner teeth, and then fixes the limiting sleeve 44 and the adjusting head 45 on the shell 2.

[0038] like Figure 1 and Figure 3-Figure 5 As shown, a highly sensitive piezoelectric vibration sensor provided by the present invention is provided. In this embodiment, the locking mechanism 3 includes a push tube 33 sleeved on the housing 2, a first slide groove 32 is provided on the side of the housing 2, a first slider 34 is fixedly connected to the inner side wall of the push tube 33, the first slider 34 is slidably connected in the first slide groove 32, an extrusion tube 35 is fixedly connected to the end side of the push tube 33, the extrusion tube 35 is sleeved on one end of the limiting sleeve 44, and the inner diameter of the extrusion tube 35 is the same as the outer diameter of the limiting sleeve 44; In order to facilitate pushing the push tube 33, the outer side surface of the push tube 33 is provided with anti-slip grooves; After the extrusion tube 35 squeezes the elastic ring sheet 43 flat, in order to prevent the extrusion tube 35 from slipping off the limiting sleeve 44 again, a compression spring 31 is arranged between the first slider 34 and the side wall of the first sliding groove 32 away from the limiting sleeve 44.

[0039] The push tube 33 is pushed upward, and the push tube 33 drives the extrusion tube 35 to move. The extrusion tube 35 leaves the side of the elastic ring piece 43, and the middle part of the elastic ring piece 43 bulges, thereby releasing the restriction of the external teeth 42 on the adjusting head 45. At this time, the adjusting head 45 can be rotated to adjust the preload force of the preload nut 18; the push tube 33 is slid downward, and the push tube 33 drives the extrusion tube 35 to squeeze the elastic ring piece 43, squeezing the elastic ring piece 43 flat, and the elastic ring piece 43 drives the external teeth 42 to be inserted between the internal teeth, thereby fixing the adjusting head 45 to prevent the preload screw 19 from rotating, and then preventing the preload force of the preload nut 18 from loosening.

[0040] like Figure 3-Figure 5 and Figure 8-Figure 10As shown, a highly sensitive piezoelectric vibration sensor provided by the present invention is provided. In the prior art, since the annular piezoelectric ceramic piece 7 is located on the extension line of the axis of the universal mass block assembly 8, only when the vibration direction of the object to be measured is parallel to the extension line of the universal mass block assembly 8, the universal mass block assembly 8 can generate pressure on the annular piezoelectric ceramic piece 7, and the annular piezoelectric ceramic piece 7 can detect the vibration of the object to be measured. The limitation of this installation method is very large, so that the sensor can only detect the vibration of the object to be measured in the vertical direction. Therefore, in this embodiment, the universal mass block assembly 8 includes a vertical mass block 82, and the The vertical mass block 82 is sleeved on the pre-tightening screw 19, and one end of the vertical mass block 82 is in contact with the annular piezoelectric ceramic plate 7. The other end of the vertical mass block 82 is provided with a cross bevel groove 83. The four ends of the cross bevel groove 83 are all inclined surfaces, and the angle between the inclined surface and the horizontal plane is 45°. A horizontal cross mass block 81 is arranged inside the cross bevel groove 83. The shape of the horizontal cross mass block 81 is consistent with the shape of the cross bevel groove 83. The horizontal cross mass block 81 is provided with a movable hole for the pre-tightening screw 19 to pass through, and the diameter of the movable hole is larger than the diameter of the pre-tightening screw 19.

[0041] When the object to be measured vibrates in the horizontal direction, the horizontal cross mass block 81 will squeeze the inclined surface of the cross bevel slot 83. The force of the horizontal cross mass block 81 on the cross bevel slot 83 will be transmitted to the vertical mass block 82 perpendicular to the direction of the inclined surface. The force will form components in the horizontal and vertical directions. The vertical component will squeeze the vertical mass block 82, so that the vertical mass block 82 squeezes the annular piezoelectric ceramic piece 7. The annular piezoelectric ceramic piece 7 can detect the vibration of the object to be measured in the horizontal direction, thereby making the device more sensitive.

[0042] like Figure 5 As shown, a high-sensitivity piezoelectric vibration sensor provided by the present invention is used. In order to avoid charge leakage on the annular piezoelectric ceramic sheet 7, which causes the sensitivity of the device to decrease, in this embodiment, an upper electrode sheet 12 is arranged on the top of the annular piezoelectric ceramic sheet 7, an upper insulating sheet 11 is arranged between the upper electrode sheet 12 and the shell 2, a lower electrode sheet 13 is arranged on the bottom of the annular piezoelectric ceramic sheet 7, a lower insulating sheet 14 is arranged between the lower electrode sheet 13 and the universal mass block assembly 8, and the upper electrode sheet 12 and the lower electrode sheet 13 are respectively connected to the positive and negative poles of the circuit board 10 through wires.

[0043] like Figure 5 As shown, a high-sensitivity piezoelectric vibration sensor provided by the present invention is provided. In order to increase the pre-tightening force between the pre-tightening nut 18 and the universal mass block assembly 8, in this embodiment, a gasket 15 is arranged between the pre-tightening nut 18 and the universal mass block assembly 8.

[0044] like Figure 5As shown, a high-sensitivity piezoelectric vibration sensor provided by the present invention is provided. In order to improve the stability of the circuit board 10, in this embodiment, an upper pad 16 and a lower pad 17 are respectively provided on both sides of the circuit board 10.

[0045] Working principle: The device is mounted on the object to be tested, and the connecting wire is inserted into the wiring slot 5, and the vibration of the object to be tested can be detected. When the object to be tested vibrates along the axial direction of the shell 2, the object to be tested will drive the vertical mass block 82 and the horizontal cross mass block 81 to squeeze the annular piezoelectric ceramic piece 7. When the object to be tested vibrates perpendicular to the axial direction of the shell 2, the object to be tested will drive the horizontal cross mass block 81 to squeeze the inclined surface of the vertical mass block 82. Under the action of the inclined surface, the force of the horizontal cross mass block 81 will produce components in both the horizontal and vertical directions, and the component along the axial direction of the shell 2 will be detected by the annular piezoelectric ceramic piece 7. Therefore, the device can detect the vibration of the object to be tested in any direction, and the sensitivity of the device is higher. When adjusting the preload force of the universal mass block assembly 8 on the annular piezoelectric ceramic sheet 7, the push tube 33 is pushed, and the push tube 33 drives the extrusion tube 35 to move, and the extrusion tube 35 leaves the side of the elastic ring sheet 43, and the middle part of the elastic ring sheet 43 bulges, thereby releasing the restriction of the external teeth 42 on the adjustment head 45. At this time, the adjustment head 45 can be rotated, and the adjustment head 45 drives the preload screw 19 to rotate. Since the preload nut 18 is restricted by the nut rack 9, the preload nut 18 moves relative to the preload screw 19, and then the preload force of the preload nut 18 can be adjusted. Therefore, no tools are needed, and the adjustment can be performed by hand. The device is more convenient to adjust the preload force and simpler to operate. Then slide the push tube 33 so that the push tube 33 drives the extrusion tube 35 to extrude the elastic ring piece 43, extrude the elastic ring piece 43 flat, and the elastic ring piece 43 drives the outer teeth 42 to be inserted between the inner teeth, thereby fixing the adjustment head 45 to prevent the pre-tightening screw 19 from rotating, thereby preventing the pre-tightening nut 18 from loosening.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0047] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A high-sensitivity piezoelectric vibration sensor, comprising a housing (2), one end of the housing (2) being provided with a fixing structure, characterized in that: The other end of the shell (2) is provided with an installation cavity, and a positioning column (20) is rotatably connected inside the installation cavity. The outer side of the positioning column (20) is sleeved with an annular piezoelectric ceramic sheet (7), and one end of the positioning column (20) is fixedly connected with a pre-tightening screw (19), and a universal mass block assembly (8) is sleeved on the pre-tightening screw (19), and the side of the universal mass block assembly (8) contacts the side of the annular piezoelectric ceramic sheet (7). A pre-tightening nut (18) is also threadedly connected to the pre-tightening screw (19), and the pre-tightening nut (18) and the universal mass block assembly (8) are in abutment with each other. A nut frame (9) is slidably connected inside the installation cavity, and the pre-tightening nut (18) is slidably connected inside the nut frame (9). The nut frame (9) is used to prevent the pre-tightening nut (18) from rotating relative to the shell (2); The end of the shell (2) is rotatably connected to a pre-tightening mechanism (4), one end of the pre-tightening screw (19) is fixedly connected to the side of the pre-tightening mechanism (4), a circuit board (10) is arranged between the nut frame (9) and the pre-tightening mechanism (4), the positive and negative electrodes of the circuit board (10) are respectively electrically connected to the positive and negative electrodes of the annular piezoelectric ceramic sheet (7) through wires, and a wiring groove (5) is provided on the side of the pre-tightening mechanism (4) away from the shell (2), a wiring post (6) is arranged inside the wiring groove (5), and the circuit board (10) is electrically connected to the wiring post (6) through a wire.

2. The high-sensitivity piezoelectric vibration sensor according to claim 1, characterized in that: The fixed structure is a connecting head (1).

3. The high-sensitivity piezoelectric vibration sensor according to claim 1, characterized in that: The nut frame (9) comprises a plurality of limiting guide blocks (92) fixedly connected to the inner wall of the installation cavity, the plurality of limiting guide blocks (92) are slidably connected to a connecting frame (91), the plurality of connecting frames (91) are fixedly connected to the same limiting frame (93), the limiting frame (93) is provided with a nut hole matched with the pre-tightening nut (18), and the pre-tightening nut (18) is slidably connected in the nut hole.

4. The high-sensitivity piezoelectric vibration sensor according to claim 1, characterized in that: The pre-tightening mechanism (4) comprises an adjusting head (45) rotatably connected to one end of the housing (2); one end of the pre-tightening screw (19) is fixedly connected to a side surface of the adjusting head (45); the adjusting head (45) is fixedly connected to a limiting sleeve (44) near the side surface of the housing (2); and the limiting sleeve (44) is sleeved on one end of the housing (2); A self-locking mechanism is provided between the limiting sleeve (44) and the housing (2).

5. The high-sensitivity piezoelectric vibration sensor according to claim 4, characterized in that: The self-locking mechanism comprises an elastic ring piece (43), the elastic ring piece (43) is arranged on a limiting sleeve (44), the elastic ring piece (43) is made of elastic metal, initially, the middle part of the side wall of the elastic ring piece (43) protrudes outward, the inner side wall of the elastic ring piece (43) is provided with a plurality of external teeth (42), the plurality of external teeth (42) are evenly distributed around the axis of the elastic ring piece (43), the side surface of the shell (2) is embedded with an internal tooth ring (41), the outer side surface of the internal tooth ring (41) is provided with a plurality of internal teeth, the plurality of internal teeth are evenly distributed around the axis of the shell (2), and the plurality of internal tooth rings (41) respectively engage with the plurality of internal teeth; The plurality of external teeth (42) are all made of elastic material; The cross-sections of the outer teeth (42) and the inner teeth are both triangular; The self-locking mechanism further comprises a locking mechanism (3), the locking mechanism (3) being slidably mounted on the housing (2), the output end of the locking mechanism (3) being sleeved on one end of a limiting sleeve (44), the locking mechanism (3) being used to press and flatten a raised portion of the elastic ring sheet (43).

6. The high-sensitivity piezoelectric vibration sensor according to claim 5, characterized in that: The locking mechanism (3) comprises a push tube (33) sleeved on the housing (2), a first slide groove (32) being provided on the side of the housing (2), a first slider (34) being fixedly connected to the inner side wall of the push tube (33), the first slider (34) being slidably connected in the first slide groove (32), an extrusion tube (35) being fixedly connected to the side of the end of the push tube (33), the extrusion tube (35) being sleeved on one end of a limiting sleeve (44), the inner diameter of the extrusion tube (35) being the same as the outer diameter of the limiting sleeve (44); A compression spring (31) is provided between the first sliding block (34) and a side wall of the first sliding groove (32) away from the limiting sleeve (44).

7. The high-sensitivity piezoelectric vibration sensor according to claim 1, characterized in that: The universal mass block assembly (8) comprises a vertical mass block (82), wherein the vertical mass block (82) is sleeved on the pre-tightening screw (19), one end of the vertical mass block (82) is in contact with the annular piezoelectric ceramic sheet (7), and the other end of the vertical mass block (82) is provided with a cross bevel groove (83), the four ends of the cross bevel groove (83) are all inclined surfaces, and the angle between the inclined surface and the horizontal plane is (45) degrees, and a horizontal cross mass block (81) is arranged inside the cross bevel groove (83), the shape of the horizontal cross mass block (81) is matched with the shape of the cross bevel groove (83), and the horizontal cross mass block (81) is provided with a movable hole for the pre-tightening screw (19) to pass through, and the diameter of the movable hole is larger than the diameter of the pre-tightening screw (19).

8. The high-sensitivity piezoelectric vibration sensor according to claim 1, characterized in that: An upper electrode sheet (12) is arranged on the top of the annular piezoelectric ceramic sheet (7), an upper insulating sheet (11) is arranged between the upper electrode sheet (12) and the shell (2), a lower electrode sheet (13) is arranged on the bottom of the annular piezoelectric ceramic sheet (7), a lower insulating sheet (14) is arranged between the lower electrode sheet (13) and the universal mass block assembly (8), and the upper electrode sheet (12) and the lower electrode sheet (13) are respectively connected to the positive and negative electrodes of the circuit board (10) through wires.

9. The high-sensitivity piezoelectric vibration sensor according to claim 1, characterized in that: A gasket (15) is provided between the pre-tightening nut (18) and the universal mass block assembly (8).

10. The high-sensitivity piezoelectric vibration sensor according to claim 1, characterized in that: An upper pad (16) and a lower pad (17) are respectively provided on both sides of the circuit board (10).

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