Intelligent straightening three-jaw chuck

Abstract

The invention discloses an intelligent straightening three-jaw chuck and relates to the technical field of machining, the intelligent straightening three-jaw chuck comprises a chuck body and an axis deviation detection mechanism, a control mechanism is arranged on the outer side of the chuck body, an axis correcting mechanism is arranged above the chuck body, and the axis deviation detection mechanism comprises a rotating disc and a vertical rod; the rotating disc is movably connected with an inserting piece and a fixing bolt through an inserting groove and a threaded hole, and the inserting piece is movably provided with a mounting frame through a limiting groove and a limiting piece. The encoder is connected with the rotating mechanism of the three-jaw chuck through the rotating disc, records the circumferential angle of the chuck, transmits data to the controller, calculates the deviation of the axis of the workpiece and outputs an adjusting signal, the height and the angle of the laser distance measuring sensor can be adjusted, and the three-jaw chuck can be conveniently matched with workpieces of different sizes.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, in particular to an intelligent straightening three-jaw chuck. Background Art

[0002] In the process of mechanical processing, the three-jaw chuck is one of the commonly used clamps. The three-jaw chuck consists of a chuck body, movable jaws and a jaw driving mechanism. Under the three jaw guide parts on the three-jaw chuck, there are threads that mesh with the flat threads on the back of the disc bevel gear. When the small bevel gear is turned through the square hole with a wrench, the disc gear rotates, and the flat threads on the back simultaneously drive the three jaws to approach or withdraw from the center to clamp workpieces of different diameters. Due to factors such as vibration and thermal deformation during the mechanical processing, the axis of the workpiece clamped by the three-jaw chuck is prone to deviation, affecting the processing accuracy;

[0003] After searching, the applicant found that a Chinese patent disclosed "a three-jaw chuck", and its publication (announcement) number is "CN220806447U". This patent mainly uses a conical arc surface as the contact surface between the chuck head on the jaw assembly of the three-jaw chuck and the truncated workpiece. Compared with the prior art, the contact area between the jaw or the jaw assembly and the clamped workpiece is increased, so the clamping effect is better. However, most of the existing correction methods rely on the operator's experience and manual adjustment, which is inefficient and low in precision. For this reason, we propose an intelligent straightening three-jaw chuck. Summary of the invention

[0004] The purpose of the present invention is to provide an intelligent straightening three-jaw chuck.

[0005] In order to solve the problems raised in the above background technology, the present invention provides the following technical solutions: an intelligent straightening three-jaw chuck, comprising a chuck and an axis deviation detection mechanism, a control mechanism is arranged on the outside of the chuck, an axis correction mechanism is arranged on the top of the chuck, the axis deviation detection mechanism comprises a rotating disk and a vertical rod, the rotating disk is movably connected with a connector and a fixing bolt through a plug-in slot and a threaded hole, the connector is movably installed with a mounting frame through a limit slot and a limit member, an encoder is fixedly installed inside the mounting frame, the vertical rod is movably connected with a rotating gear through a retaining ring, the retaining ring is movably connected with a rotating frame and a laser ranging sensor through a threaded groove, the control mechanism comprises a mounting sleeve, the mounting sleeve is fixedly installed with a driver through a mounting seat, a multi-port controller is fixedly installed inside the driver, the axis correction mechanism comprises three groups of jaws, two groups of piezoelectric ceramics are fixedly installed inside the three groups of jaws, and strain gauges are fixedly installed on the sides of the three groups of jaws.

[0006] As a further solution of the present invention: three groups of slide grooves are provided on the upper surface of the chuck, a mounting collar is fixedly installed on the outer wall of the chuck, and a hollow slip ring is fixedly installed on the bottom of the chuck.

[0007] As a further solution of the present invention: the rotating disk is fixedly installed at the bottom of the chuck, the hollow slip ring is located on the inner side of the rotating disk, the plug-in slot is opened on the outer wall of the rotating disk, the threaded hole is opened at the middle position of the plug-in slot, the connector is inserted into the inside of the plug-in slot, and the fixing bolt is threadedly connected to the inside of the threaded hole.

[0008] As a further solution of the present invention: the limit groove is opened on the front side of the plug-in component, the upper and lower ends of the limit groove are provided with limit holes, the limit component is inserted into the inside of the limit groove, the mounting frame is fixedly installed on the front side of the limit component, the upper and lower ends of the limit component are provided with expansion grooves, and an elastic expansion component is fixedly installed inside the expansion groove, and the size of the elastic expansion component is adapted to the limit hole.

[0009] As a further solution of the present invention: the bottom of the vertical pole is fixedly installed in the middle position of the upper surface of the mounting seat, the retaining ring is slidably connected to the outer wall of the vertical pole, the threaded groove is arranged on the outer wall of the retaining ring near the upper end position, the rotating frame is rotatably connected to the outer wall of the threaded groove, the laser ranging sensor is fixedly installed on the front side of the rotating frame, the outer wall of the retaining ring is meshed with a rotating gear, the back side of the rotating gear is provided with a motor, and the back side of the motor is fixedly installed on the side of the mounting seat.

[0010] As a further solution of the present invention: the mounting sleeve is rotatably connected to the outer wall of the mounting collar, the mounting seat is fixedly mounted on the outer wall of the mounting sleeve, and the driver is fixedly mounted on the front side of the mounting seat.

[0011] As a further solution of the present invention: a mounting back plate is fixedly mounted on the right side surface of the mounting seat.

[0012] As a further solution of the present invention: the three groups of the clamping claws are slidably connected inside the sliding groove, and the bottoms of the three groups of the clamping claws are all provided with tooth grooves, and the tooth grooves are connected to the rotating components in the chuck.

[0013] As a further solution of the present invention: the three groups of claws are provided with wire outlet holes inside, the connecting wires of the piezoelectric ceramics and the strain gauge are passed through the wire outlet holes, and the connecting wires of the piezoelectric ceramics and the strain gauge are fixedly mounted on the hollow slip ring.

[0014] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. The present invention sets an axis deviation detection mechanism, and the laser distance sensor is responsible for measuring the distance from the workpiece axis to the laser distance sensor. The encoder is connected to the rotating mechanism of the three-jaw chuck through a rotating disk, records the circumferential angle of the chuck, and transmits the data to the controller, calculates the deviation of the workpiece axis, and outputs an adjustment signal. The height and angle of the laser distance sensor can be adjusted, which is convenient for adapting to workpieces of different sizes;

[0016] 2. The present invention sets a control mechanism, and the multi-port controller is embedded in the driver and becomes a part of the driver. The control system receives data from the laser distance sensor and the encoder, calculates the axis deviation and makes adjustments. The entire control mechanism is connected to the lathe by installing a back plate, so that the control mechanism remains stationary when the chuck rotates, avoiding affecting the detected data. At the same time, the mounting bracket is rotatably connected to the outer wall of the mounting collar, so that the distance between the driver and the chuck remains unchanged, avoiding the problems of inaccurate detection data caused by the distance between the driver and the chuck being too far when manually installed, unsatisfactory detection effect caused by the distance being too close, and easy splashing of debris from workpiece processing onto the controller during the detection process, causing damage to the controller.

[0017] 3. The present invention sets up an axis correction mechanism and controls the displacement of the piezoelectric ceramic through a driver, thereby finely adjusting the position of the workpiece to correct the axis deviation. During the adjustment process, the strain gauge monitors the clamping force of the claw on the workpiece in real time. When the clamping force is too large or too small, the control system will receive a signal and automatically adjust according to a preset safety range to ensure the safety and stability of the processing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall three-dimensional structure in an embodiment of the present invention;

[0019] Figure 2 An exploded view of a part of the structure in an embodiment of the present invention;

[0020] Figure 3 It is a partial structural schematic diagram of an axis deviation detection mechanism in an embodiment of the present invention;

[0021] Figure 4 This is one of the exploded views of the axis deviation detection mechanism in the embodiment of the present invention;

[0022] Figure 5 This is the second exploded view of the axis deviation detection mechanism in the embodiment of the present invention;

[0023] Figure 6 This is the third exploded view of the axis deviation detection mechanism in the embodiment of the present invention;

[0024] Figure 7Schematic diagram of the three-dimensional structure of the control mechanism in an embodiment of the present invention;

[0025] Figure 8 It is a left side view of a part of the structure of the axis correction mechanism in the embodiment of the present invention;

[0026] Fig. 9 It is a right view of the partial structure of the axis correction mechanism in an embodiment of the present invention.

[0027] Figure: 1, chuck; 2, slide; 3, mounting ring; 4, hollow slip ring; 5, axis deviation detection mechanism; 501, rotating disk; 502, plug-in slot; 503, threaded hole; 504, plug-in; 505, fixing bolt; 506, limit slot; 507, limit hole; 508, mounting bracket; 509, encoder; 510, limit piece; 511, telescopic slot; 512, elastic telescopic piece; 513, vertical Rod; 514, retaining ring; 515, motor; 516, rotating gear; 517, threaded groove; 518, rotating frame; 519, laser ranging sensor; 6, control mechanism; 61, mounting bracket; 62, mounting seat; 63, driver; 64, multi-port controller; 65, mounting back plate; 7, axis correction mechanism; 71, claw; 72, wire outlet hole; 73, tooth groove; 74, strain gauge; 75, piezoelectric ceramic. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0029] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Please refer to the attached Figure 1 -Attached Fig. 9The intelligent straightening three-jaw chuck of the present invention comprises a chuck 1 and an axis deviation detection mechanism 5, a control mechanism 6 is arranged on the outside of the chuck 1, an axis correction mechanism 7 is arranged on the top of the chuck 1, the axis deviation detection mechanism 5 comprises a rotating disk 501 and a vertical rod 513, the rotating disk 501 is movably connected with a plug-in component 504 and a fixing bolt 505 through a plug-in slot 502 and a threaded hole 503, the plug-in component 504 is movably installed with a mounting frame 508 through a limit slot 506 and a limit component 510, an encoder 509 is fixedly installed inside the mounting frame 508, and a vertical rod 513 is provided. The rod 513 is movably connected to the rotating gear 516 through the retaining ring 514, and the retaining ring 514 is movably connected to the rotating frame 518 and the laser ranging sensor 519 through the threaded groove 517. The control mechanism 6 includes a mounting sleeve 61, and the mounting sleeve 61 is fixedly installed with a driver 63 through a mounting seat 62. A multi-port controller 64 is fixedly installed inside the driver 63. The axis correction mechanism 7 includes three groups of claws 71, and two groups of piezoelectric ceramics 75 are fixedly installed inside the three groups of claws 71. Strain gauges 74 are fixedly installed on the sides of the three groups of claws 71.

[0031] In one embodiment of the present invention: three groups of slide grooves 2 are provided on the upper surface of the chuck 1 , a mounting collar 3 is fixedly mounted on the outer wall of the chuck 1 , and a hollow slip ring 4 is fixedly mounted on the bottom of the chuck 1 .

[0032] In one embodiment of the present invention: the rotating disk 501 is fixedly installed at the bottom of the chuck 1, the hollow slip ring 4 is located on the inner side of the rotating disk 501, the plug-in slot 502 is opened on the outer wall of the rotating disk 501, the threaded hole 503 is opened at the middle position of the plug-in slot 502, the plug-in component 504 is inserted into the inside of the plug-in slot 502, and the fixing bolt 505 is threadedly connected to the inside of the threaded hole 503.

[0033] In one embodiment of the present invention: a limit groove 506 is provided on the front side of the connector 504, and limit holes 507 are provided at both the upper and lower ends of the limit groove 506, a limit member 510 is plugged into the inside of the limit groove 506, a mounting frame 508 is fixedly installed on the front side of the limit member 510, and telescopic grooves 511 are provided at both the upper and lower ends of the limit member 510, and an elastic telescopic member 512 is fixedly installed inside the telescopic groove 511, and the size of the elastic telescopic member 512 is adapted to the limit hole 507.

[0034] In one embodiment of the present invention: the bottom of the vertical rod 513 is fixedly mounted at the middle position of the upper surface of the mounting seat 62, the retaining ring 514 is slidably connected to the outer wall of the vertical rod 513, the threaded groove 517 is arranged on the outer wall of the retaining ring 514 near the upper end position, the rotating frame 518 is rotatably connected to the outer wall of the threaded groove 517, the laser ranging sensor 519 is fixedly mounted on the front side of the rotating frame 518, the outer wall of the retaining ring 514 is meshed with a rotating gear 516, the back of the rotating gear 516 is provided with a motor 515, and the back of the motor 515 is fixedly mounted on the side of the mounting seat 62.

[0035] In one embodiment of the present invention: the mounting bracket 61 is rotatably connected to the outer wall of the mounting collar 3 , the mounting seat 62 is fixedly mounted on the outer wall of the mounting bracket 61 , and the driver 63 is fixedly mounted on the front side of the mounting seat 62 .

[0036] In one embodiment of the present invention, a mounting back plate 65 is fixedly mounted on the right side surface of the mounting seat 62 .

[0037] In one embodiment of the present invention, three groups of jaws 71 are slidably connected inside the slide groove 2 , and tooth grooves 73 are formed at the bottom of the three groups of jaws 71 , which are connected to the rotating assembly in the chuck 1 .

[0038] In one embodiment of the present invention: the three groups of claws 71 are each provided with a wire outlet hole 72 , the connecting wires of the piezoelectric ceramic 75 and the strain gauge 74 are passed through the wire outlet hole 72 , and the connecting wires of the piezoelectric ceramic 75 and the strain gauge 74 are fixedly mounted on the hollow slip ring 4 .

[0039] Example 1, please refer to the attached Figure 1 -Attached Figure 2 The hollow slip ring 4 provides stable power and data transmission for the driver 63, ensures the continuity of the signal during the rotation process, and avoids the entanglement problem of the connecting wires of the piezoelectric ceramic 75 and the strain gauge 74 when the chuck 1 rotates. The hollow slip ring 4 allows the connecting wires to pass freely when the chuck 1 rotates to avoid entanglement or damage of the wires.

[0040] Example 2, please refer to the attached Figure 1 -Attached Figure 6 The encoder 509 is fixedly mounted on the mounting frame 508 , and the encoder 509 can be quickly installed and removed from the chuck 1 by inserting and removing the limiting member 510 in the limiting groove 506 , so that the encoder 509 can be easily repaired.

[0041] Example 3, please refer to the attached Figure 1 -Attached Figure 7The control mechanism 6 is connected to the lathe through the mounting back plate 65, so that the mounting sleeve 61 rotates along the mounting ring 3 of the chuck 1, thereby preventing the driver 63, the multi-port controller 64 and the laser ranging sensor 519 from rotating and affecting the detection data.

[0042] Example 4, please refer to the attached Figure 1 -Attached Fig. 9 By applying a suitable voltage signal to the piezoelectric ceramic 75 , it can be deformed to achieve a small displacement. By utilizing this characteristic, the piezoelectric ceramic 75 can be accurately controlled to move within a certain range, thereby indirectly achieving fine-tuning control of the position of the claw 71 .

[0043] Specifically, the laser ranging sensor 519 is responsible for measuring the distance from the axis of the workpiece to the laser ranging sensor 519, and the encoder 509 is connected to the rotating mechanism of the chuck 1 through the rotating disk 501, records the circumferential angle of the chuck 1, and transmits the data to the controller, calculates the deviation of the axis of the workpiece, and outputs an adjustment signal. The height and angle of the laser ranging sensor 519 can be adjusted to facilitate adaptation to workpieces of different sizes.

[0044] Specifically, the multi-port controller 64 is embedded in the driver 63 and becomes a part of the driver 63. The control system receives data from the laser ranging sensor 519 and the encoder 509, calculates the axis deviation and makes adjustments, and connects the entire control mechanism 6 to the lathe by installing the back plate 65, so that the control mechanism 6 remains stationary when the chuck 1 rotates to avoid affecting the detected data. At the same time, the mounting sleeve 61 is rotatably connected to the outer wall of the mounting ring 3 to keep the distance between the driver 63 and the chuck 1 fixed, thereby avoiding the problems of inaccurate detection data caused by the distance between the driver 63 and the chuck 1 being too far when manually installed, unsatisfactory detection effect caused by the distance being too close, and easy splashing of debris from the workpiece processing onto the driver 63 during the detection process to damage the driver 63.

[0045] Specifically, the displacement of the piezoelectric ceramic 75 is controlled by the driver 63, so as to finely adjust the position of the workpiece to correct the axis deviation. During the adjustment process, the strain gauge 74 monitors the clamping force of the claw 71 on the workpiece in real time. When the clamping force is too large or too small, the control system will receive a signal and automatically adjust according to the preset safety range to ensure the safety and stability of the processing process.

[0046] Working principle:

[0047] First, insert the connector 504 into the inside of the plug-in slot 502, then tighten the fixing bolt 505 into the inside of the threaded hole 503, then press the elastic telescopic member 512 to make it completely retract into the inside of the telescopic slot 511, insert the limiting member 510 into the inside of the limiting slot 506, until the elastic telescopic member 512 pops out from the limiting hole 507, complete the connection between the encoder 509 and the rotating disk 501, and then drive the rotating gear 516 to rotate through the motor 515, so that the retaining ring 514 is raised and lowered along the vertical rod 513, and the angle of the laser distance sensor 519 is adjusted by the rotation of the rotating frame 518 on the threaded groove 517, and then the laser distance sensor 519 is aligned with the axis of the workpiece to be detected. The laser distance sensor 519 is responsible for measuring the distance from the axis of the workpiece to the laser distance sensor 519, the encoder 509 is connected to the rotating mechanism of the chuck 1 through the rotating disk 501, records the circumferential angle of the chuck 1, and transmits the data to the controller, calculates the deviation of the workpiece axis, outputs an adjustment signal, and controls the displacement of the piezoelectric ceramic 75 through the driver 63, so as to finely adjust the position of the workpiece to correct the axis deviation. During the adjustment process, the strain gauge 74 monitors the clamping force of the claw 71 on the workpiece in real time. When the clamping force is too large or too small, the control system will receive a signal and automatically adjust according to the preset safety range to ensure the safety and stability of the processing process. The entire control mechanism 6 is connected to the lathe by installing the back plate 65, so that the control mechanism 6 remains stationary when the chuck 1 rotates to avoid affecting the detected data. At this point, the entire workflow ends.

[0048] The above-mentioned front, back, left, right, top and bottom are all based on the figures in the specification. Figure 1 As a benchmark, according to the person's observation perspective, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0049] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0050] It should be noted that the device structure and the drawings of the present invention mainly describe the principle of the present invention. In terms of the technology of the design principle, the settings of the power mechanism, power supply system and control system of the device are not fully described. On the premise that the technical personnel in this field understand the principle of the above invention, the details of the power mechanism, power supply system and control system can be clearly known. The control method of the application document is automatic control through a controller, and the control circuit of the controller can be realized by simple programming by the technical personnel in this field.

[0051] The standard parts used therein can all be purchased from the market and can be customized according to the instructions and drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the prior art. The machinery, parts and equipment all adopt conventional models in the prior art, and the structures and principles of the components known to technical personnel in this field can be known by these technical personnel through technical manuals or through conventional experimental methods.

[0052] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations are made to these embodiments without departing from the principle and spirit of the present invention, and they still fall within the protection scope of the present invention.

Claims

1. An intelligent straightening three-jaw chuck, comprising a chuck (1) and an axis deviation detection mechanism (5), characterized in that: A control mechanism (6) is provided on the outside of the chuck (1), and an axis correction mechanism (7) is provided above the chuck (1); The axis deviation detection mechanism (5) comprises a rotating disk (501) and a vertical rod (513); the rotating disk (501) is movably connected to a plug-in component (504) and a fixing bolt (505) through a plug-in slot (502) and a threaded hole (503); the plug-in component (504) is movably mounted with a mounting frame (508) through a limit slot (506) and a limit component (510); an encoder (509) is fixedly mounted inside the mounting frame (508); the vertical rod (513) is movably connected to a rotating gear (516) through a snap ring (514); the snap ring (514) is movably connected to a rotating frame (518) and a laser distance sensor (519) through a threaded slot (517); The control mechanism (6) comprises a mounting frame (61), a driver (63) being fixedly mounted on the mounting frame (61) via a mounting seat (62), and a multi-port controller (64) being fixedly mounted inside the driver (63); The axis correction mechanism (7) comprises three groups of clamping claws (71), two groups of piezoelectric ceramics (75) are fixedly installed inside the three groups of clamping claws (71), and strain gauges (74) are fixedly installed on the sides of the three groups of clamping claws (71).

2. The intelligent straightening three-jaw chuck according to claim 1 is characterized in that: The upper surface of the chuck (1) is provided with three groups of slide grooves (2), a mounting collar (3) is fixedly mounted on the outer wall of the chuck (1), and a hollow sliding ring (4) is fixedly mounted on the bottom of the chuck (1).

3. The intelligent straightening three-jaw chuck according to claim 2 is characterized in that: The rotating disk (501) is fixedly mounted on the bottom of the chuck (1), the hollow slip ring (4) is located on the inner side of the rotating disk (501), the plug-in slot (502) is provided on the outer wall of the rotating disk (501), the threaded hole (503) is provided at the middle position of the plug-in slot (502), the plug-in component (504) is plugged into the inside of the plug-in slot (502), and the fixing bolt (505) is threadedly connected to the inside of the threaded hole (503).

4. The intelligent straightening three-jaw chuck according to claim 3 is characterized in that: The limiting groove (506) is provided on the front side of the plug-in component (504); limiting holes (507) are provided at both upper and lower ends of the limiting groove (506); the limiting component (510) is plugged into the inside of the limiting groove (506); the mounting frame (508) is fixedly mounted on the front side of the limiting component (510); telescopic grooves (511) are provided at both upper and lower ends of the limiting component (510); an elastic telescopic component (512) is fixedly mounted inside the telescopic groove (511); the size of the elastic telescopic component (512) is adapted to the limiting hole (507).

5. The intelligent straightening three-jaw chuck according to claim 4 is characterized in that: The bottom of the vertical rod (513) is fixedly mounted at the middle position of the upper surface of the mounting seat (62); the retaining ring (514) is slidably connected to the outer wall of the vertical rod (513); the thread groove (517) is arranged on the outer wall of the retaining ring (514) near the upper end; the rotating frame (518) is rotatably connected to the outer wall of the thread groove (517); the laser ranging sensor (519) is fixedly mounted on the front side of the rotating frame (518); a rotating gear (516) is meshed on the outer wall of the retaining ring (514); a motor (515) is arranged on the back side of the rotating gear (516); and the back side of the motor (515) is fixedly mounted on the side of the mounting seat (62).

6. The intelligent straightening three-jaw chuck according to claim 2 is characterized in that: The mounting sleeve (61) is rotatably connected to the outer wall of the mounting collar (3), the mounting seat (62) is fixedly mounted on the outer wall of the mounting sleeve (61), and the driver (63) is fixedly mounted on the front side of the mounting seat (62).

7. The intelligent straightening three-jaw chuck according to claim 6 is characterized in that: A mounting back plate (65) is fixedly mounted on the right side of the mounting seat (62).

8. The intelligent straightening three-jaw chuck according to claim 2 is characterized in that: The three groups of clamping claws (71) are slidably connected inside the slide groove (2), and the bottoms of the three groups of clamping claws (71) are all provided with tooth grooves (73), and the tooth grooves (73) are connected to the rotating components in the chuck (1).

9. The intelligent straightening three-jaw chuck according to claim 8, characterized in that: The three groups of clamping claws (71) are each provided with a wire outlet hole (72), and the connecting wires of the piezoelectric ceramic (75) and the strain gauge (74) are passed through the inside of the wire outlet hole (72), and the connecting wires of the piezoelectric ceramic (75) and the strain gauge (74) are fixedly mounted on the hollow slip ring (4).

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