CN111152187B - Joint locking mechanism based on piezoelectric driving and working method thereof - Google Patents

Abstract

The invention discloses a joint locking mechanism based on piezoelectric driving and a working method thereof, wherein the joint locking mechanism comprises a first locking piece, a second locking piece and a threaded locking rod; the threaded lock rod comprises a stud, a light column and a limiting disc which are coaxially and fixedly connected in sequence; the first locking piece comprises a balancing weight, a plurality of annular piezoelectric elements, a connecting column, countersunk bolts, a flange plate and a threaded pipe; the second lock member includes a drive stator and first to fourth rectangular piezoelectric elements. The invention converts electric energy into mechanical energy by utilizing the inverse piezoelectric effect of the piezoelectric material, pushes the screw to screw in, realizes accurate butt joint of the rails, does not need complex transmission and speed reduction mechanisms, has simple and compact structure, is easy to realize miniaturization, and can work in a strong magnetic field and vacuum environment.

Description

A joint locking mechanism based on piezoelectric drive and its working method

technical field

The invention relates to piezoelectric drive technology, in particular to a piezoelectric drive-based joint locking mechanism and a working method thereof.

Background technique

The robot maintenance system of the tokamak device is laid with multi-section tracks suspended in the air, and the adjacent tracks need to be matched and fixed. Since the tokamak device operates under extreme working conditions such as strong magnetism, super large current, ultra-low temperature, and extremely high temperature, Devices powered by electromagnetic motors cannot operate with high precision in this environment. Many maintenance systems consider docking the tracks in the tokamak device to form a detection track, but there are still problems such as inaccurate docking and complex structures.

Contents of the invention

The technical problem to be solved by the present invention is to provide a piezoelectric-driven joint locking mechanism and its working method for the defects involved in the background technology.

The present invention adopts the following technical solutions for solving the problems of the technologies described above:

A joint locking mechanism based on piezoelectric drive, comprising a first lock, a second lock and a threaded lock rod;

The threaded locking rod includes a stud, a light column and a limiting disk that are coaxially fixed in sequence, the bottom surface radius of the stud and the light column are the same, and the bottom surface radius of the limiting disk is larger than the bottom surface radius of the light column;

The first lock includes counterweights, first to fourth annular piezoelectric elements, first to third electrode sheets, connecting columns, countersunk bolts, flanges and threaded pipes;

The counterweight is a cylinder, which is provided with a countersunk through hole along the axis; the connecting column is a cylinder, and the center line of one end surface is provided with a threaded hole matching the countersunk bolt; the countersunk The bolts pass through the countersunk through hole of the counterweight, the first annular piezoelectric element, the first electrode sheet, the second annular piezoelectric element, the second electrode sheet, the third annular piezoelectric element, The third electrode sheet and the fourth ring-shaped piezoelectric element are connected to the threaded hole of the connecting column, and the first to fourth ring-shaped piezoelectric elements and the first to third electrode sheets are fixed on the counterweight and connecting column;

The threaded pipe is a hollow cylinder with openings at both ends, and its inner wall is provided with threads matching the studs of the threaded locking rod;

One end of the flange is fixedly connected to one end of the threaded pipe, and the other end is fixedly connected to the end of the connecting column away from the counterweight, and a number of holes for fixing the first lock are uniformly arranged in the circumferential direction of the flange. through hole;

The second lock includes a drive stator and first to fourth rectangular piezoelectric elements;

The driving stator is a cuboid, including a first end face, a second end face, and first to fourth side faces, wherein the first end face and the second end face are both square, the first to fourth side faces are connected in sequence, and the first side faces are parallel to each other. On the third side, the second side is parallel to the fourth side; the drive stator is provided with a threaded through hole matching the stud of the threaded locking rod along the axis;

The first end surface is provided with a plurality of threaded holes for fixing the second lock;

The first to fourth rectangular piezoelectric elements are arranged on the first to fourth side surfaces of the driving stator in one-to-one correspondence;

The length of the threaded through hole of the driving stator is less than the length of the threaded locking rod light column, the length of the threaded pipe is greater than the length of the threaded locking rod stud, and the length difference between the threaded pipe and the threaded locking rod stud is greater than the threaded length of the driving stator. The length difference between the through hole and the threaded locking rod light column;

The first to fourth ring-shaped piezoelectric elements are all polarized along their thickness direction, and there are two partitions along the dividing line along their diameters, and the polarization directions of the two partitions are opposite; the first ring-shaped piezoelectric element and the second ring-shaped piezoelectric element The partition lines of the two ring-shaped piezoelectric elements are parallel, and the polarization directions of the partitions on the same side are opposite; the partition lines of the third ring-shaped piezoelectric element and the second ring-shaped piezoelectric element are perpendicular to each other; The partition lines of the fourth annular piezoelectric element and the third annular piezoelectric element are parallel, and the polarization directions of the same side partitions are opposite;

The first to fourth rectangular piezoelectric elements are all polarized along their thickness direction, the first rectangular piezoelectric element and the third rectangular piezoelectric element have the same polarization direction, the second rectangular piezoelectric element and the fourth rectangular piezoelectric element The direction of polarization is the same.

The present invention also discloses a method for driving the second lock element based on the piezo-electrically driven joint locking mechanism, which includes the following steps:

Step A.1), simultaneously apply the first-phase simple harmonic voltage signal to the first and third rectangular piezoelectric elements, apply the second-phase simple harmonic voltage signal to the second rectangular piezoelectric element and the fourth rectangular piezoelectric element, and excite The drive stator has a homomorphic bending vibration mode with a phase difference of π/2 in space, adjust the phase difference of the first and second simple harmonic voltage signals to π/2 in time, and the coupling of the two modes makes the threaded through hole appear Rotational bending vibration drives the thread lock rod to screw in or out under the engagement of the thread;

Step A.2), if it is necessary to move the thread lock rod in reverse, adjust the phase difference of the two-phase simple harmonic voltage signal to -π/2 in time, and the threaded through hole performs opposite rotational bending vibration, and the thread is driven under the engagement of the thread The locking lever moves in reverse.

The present invention also discloses a method for driving the first lock piece based on the piezo-electrically driven joint locking mechanism, which includes the following steps:

Step B.1), at the same time, apply two-phase simple harmonic voltage signals to the first electrode piece and the third electrode piece respectively, to excite the homomorphic bending vibration mode of the threaded pipe with a phase difference of π/2 in space, and adjust the two phases The phase difference of the simple harmonic voltage signal in time is π/2, and the coupling of the two modes causes the threaded tube to exhibit rotational bending vibration, which drives the threaded locking rod to screw in or out under the engagement of the thread;

Step B.2), if it is necessary to move the thread lock rod in reverse, adjust the phase difference of the two-phase simple harmonic voltage signal to -π/2 in time, and the threaded pipe will rotate and bend in the opposite direction, and drive the thread lock under the engagement of the thread The rod moves in the opposite direction.

Compared with the prior art, the present invention adopts the above technical scheme and has the following technical effects:

The piezoelectric driving method based on the inverse piezoelectric effect can realize the characteristics of compact structure, direct drive, no electromagnetic interference, and easy miniaturization of the driving structure under the condition that the preparation and processing technology of piezoelectric ceramic materials have been further developed. The owner has a wide range of application prospects in extreme working environments. The joint locking mechanism proposed by the present invention can realize rapid and precise docking of rails, simple mechanism, and miniaturization, and can work in extreme environments such as vacuum and strong magnetic fields.

Description of drawings

Fig. 1 is the structural representation of the joint locking mechanism based on piezoelectric drive of the present invention;

Fig. 2 is a structural representation of the first lock in the present invention;

Fig. 3 is the structural representation of the second lock in the present invention;

Fig. 4 is the structural representation of thread lock bar in the present invention;

Fig. 5 is a schematic view of the structure of the track for fixing the first lock;

Fig. 6 is a schematic structural view of the cooperation between the track and the first lock;

Fig. 7 is a schematic view of the structure of the track for fixing the second lock;

Fig. 8 is a structural schematic view of the cooperation between the track and the second lock;

Fig. 9 is a schematic diagram before two rails are docked;

Fig. 10 is a schematic diagram of two rails after they are docked through the joint locking mechanism;

Fig. 11 is a schematic diagram of the polarization modes of the first to fourth annular piezoelectric elements and the application mode of electrical signals of the first to third electrode sheets;

Fig. 12 is a schematic diagram of the polarization mode and the electrical signal application mode of the first to fourth rectangular piezoelectric elements.

In the figure, 1-first lock piece, 2-second lock piece, 3-thread lock rod, 4-counterweight, 5-circular piezoelectric element, 6 connecting column, 7-flange, 8- Threaded pipe, 9-drive stator, 10-first rectangular piezoelectric element, 11-first end face of drive stator, 12-stud, 13-light column, 14-limiting disk.

Detailed ways

Below in conjunction with accompanying drawing, technical scheme of the present invention is described in further detail:

This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, components are exaggerated for clarity.

As shown in FIG. 1 , the present invention discloses a piezo-electrically driven joint locking mechanism, which includes a first lock, a second lock and a threaded lock rod.

As shown in FIG. 4 , the threaded locking rod includes a stud, a light column and a limiting disk that are coaxially connected in sequence. The bottom surfaces of the stud and the light column have the same radius, and the bottom radius of the limiting disk is greater than that of the light column.

As shown in Figure 2, the first lock includes counterweights, first to fourth annular piezoelectric elements, first to third electrode sheets, connecting posts, countersunk bolts, flanges and threaded pipes ;

The counterweight is a cylinder, which is provided with a countersunk through hole along the axis; the connecting column is a cylinder, and the center line of one end surface is provided with a threaded hole matching the countersunk bolt; the countersunk The bolts pass through the countersunk through hole of the counterweight, the first annular piezoelectric element, the first electrode sheet, the second annular piezoelectric element, the second electrode sheet, the third annular piezoelectric element, The third electrode sheet and the fourth ring-shaped piezoelectric element are connected to the threaded hole of the connecting column, and the first to fourth ring-shaped piezoelectric elements and the first to third electrode sheets are fixed on the counterweight and connecting column;

The threaded pipe is a hollow cylinder with openings at both ends, and its inner wall is provided with threads matching the studs of the threaded locking rod;

One end of the flange is fixedly connected to one end of the threaded pipe, and the other end is fixedly connected to the end of the connecting column away from the counterweight, and a number of holes for fixing the first lock are uniformly arranged in the circumferential direction of the flange. through hole.

As shown in Figure 3, the second lock includes a driving stator and first to fourth rectangular piezoelectric elements;

The driving stator is a cuboid, including a first end face, a second end face, and first to fourth side faces, wherein the first end face and the second end face are both square, the first to fourth side faces are connected in sequence, and the first side faces are parallel to each other. On the third side, the second side is parallel to the fourth side; the drive stator is provided with a threaded through hole matching the stud of the threaded locking rod along the axis;

The first end surface is provided with a plurality of threaded holes for fixing the second lock;

The first to fourth rectangular piezoelectric elements are arranged one by one on the first to fourth side surfaces of the driving stator.

The length of the threaded through hole of the driving stator is less than the length of the threaded locking rod light column, the length of the threaded pipe is greater than the length of the threaded locking rod stud, and the length difference between the threaded pipe and the threaded locking rod stud is greater than the threaded length of the driving stator. The length difference between the through hole and the threaded locking rod light column;

As shown in Figure 11, the first to fourth ring-shaped piezoelectric elements are all polarized along their thickness direction, and there are two partitions along their diameters, and the polarization directions of the two partitions are opposite; the first ring The partition lines of the piezoelectric element and the second annular piezoelectric element are parallel, and the polarization directions of the partitions on the same side are opposite; the partitions of the third annular piezoelectric element and the second annular piezoelectric element are divided The boundary lines are perpendicular to each other; the boundary lines of the partitions of the fourth annular piezoelectric element and the third annular piezoelectric element are parallel, and the polarization directions of the partitions on the same side are opposite;

As shown in Figure 12, the first to fourth rectangular piezoelectric elements are all polarized along their thickness direction, the first rectangular piezoelectric element and the third rectangular piezoelectric element have the same polarization direction, the second rectangular piezoelectric element and the third rectangular piezoelectric element have the same polarization direction. The polarization directions of the fourth rectangular piezoelectric elements are the same.

The present invention also discloses a method for driving the second lock element based on the piezo-electrically driven joint locking mechanism, which includes the following steps:

Step A.1), simultaneously apply the first-phase simple harmonic voltage signal to the first and third rectangular piezoelectric elements, apply the second-phase simple harmonic voltage signal to the second rectangular piezoelectric element and the fourth rectangular piezoelectric element, and excite The drive stator has a homomorphic bending vibration mode with a phase difference of π/2 in space, adjust the phase difference of the first and second simple harmonic voltage signals to π/2 in time, and the coupling of the two modes makes the threaded through hole appear Rotational bending vibration drives the thread lock rod to screw in or out under the engagement of the thread;

Step A.2), if it is necessary to move the thread lock rod in reverse, adjust the phase difference of the two-phase simple harmonic voltage signal to -π/2 in time, and the threaded through hole performs opposite rotational bending vibration, and the thread is driven under the engagement of the thread The locking lever moves in reverse.

The present invention also discloses a method for driving the first lock piece based on the piezo-electrically driven joint locking mechanism, which includes the following steps:

Step B.1), at the same time, apply two-phase simple harmonic voltage signals to the first electrode piece and the third electrode piece respectively, to excite the homomorphic bending vibration mode of the threaded pipe with a phase difference of π/2 in space, and adjust the two phases The phase difference of the simple harmonic voltage signal in time is π/2, and the coupling of the two modes causes the threaded tube to exhibit rotational bending vibration, which drives the threaded locking rod to screw in or out under the engagement of the thread;

Step B.2), if it is necessary to move the thread lock rod in reverse, adjust the phase difference of the two-phase simple harmonic voltage signal to -π/2 in time, and the threaded pipe will rotate and bend in the opposite direction, and drive the thread lock under the engagement of the thread The rod moves in the opposite direction.

The application of the present invention will be further explained below with the docking of the first and second rails.

One end of the first track is provided with a first fixing plate for matching with the flange of the first lock, as shown in Figure 5, and the first lock is fixed to one end of the first track through its flange, as shown in Figure 6 shown.

One end of the second track is provided with a second fixed plate for matching with the threaded hole on the first end face of the second lock, as shown in Figure 7, the second lock is fixed on one end of the second track by screws, as shown in Figure 7 8.

When the first and second rails are not docked, as shown in Figure 9.

When it needs to be docked and fixed, align the threaded tube of the first lock on the first track with the threaded through hole of the second lock on the second track, and drive the stud of the threaded lock rod to the second lock of the stator by the second lock. The end face is screwed into the threaded through hole of the driving stator of the second lock; firstly, the second lock is driven so that the stud of the threaded locking rod passes through the first end face of the driving stator of the second lock and then screwed into the threaded tube of the first lock Then drive the first lock, so that the stud of the threaded lock rod is continuously screwed into the threaded pipe, until the second lock drives the stator without studs, only the polished rod, and the limit disc is against the second lock When the component drives the second end face of the stator, the threaded lock rod limit disc will make the second track keep approaching the first track until the first and second tracks are completely docked and locked, as shown in Figure 10.

Those skilled in the art can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this invention belongs. It should also be understood that terms such as those defined in commonly used dictionaries should be understood to have a meaning consistent with the meaning in the context of the prior art, and unless defined as herein, are not to be interpreted in an idealized or overly formal sense explain.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (3)

1. The joint locking mechanism based on piezoelectric driving is characterized by comprising a first locking piece, a second locking piece and a threaded locking rod;

the threaded lock rod comprises a stud, a light column and a limiting disc which are coaxially and fixedly connected in sequence, the radiuses of the bottoms of the stud and the light column are the same, and the radius of the bottom of the limiting disc is larger than that of the light column;

the first locking piece comprises a balancing weight, first to fourth annular piezoelectric elements, first to third electrode plates, a connecting column, a countersunk bolt, a flange plate and a threaded pipe;

the balancing weight is a cylinder, and a countersunk through hole is formed along the axis of the balancing weight; the connecting column is a cylinder, and a threaded hole matched with the countersunk head bolt is formed in the center line of one end face of the connecting column; the countersunk head bolts sequentially pass through countersunk head through holes of the balancing weights, the first annular piezoelectric elements, the first electrode plates, the second annular piezoelectric elements, the second electrode plates, the third annular piezoelectric elements, the third electrode plates and the fourth annular piezoelectric elements and then are connected with screw threads of screw holes of the connecting columns, and the first to fourth annular piezoelectric elements and the first to third electrode plates are fixed between the balancing weights and the connecting columns;

the threaded pipe is a hollow cylinder with openings at two ends, and threads matched with the studs of the threaded lock rod are arranged on the inner wall of the threaded pipe;

one end of the flange plate is fixedly connected with one end of the threaded pipe, the other end of the flange plate is fixedly connected with one end of the connecting column, which is far away from the balancing weight, and a plurality of through holes for fixing the first locking piece are uniformly formed in the circumferential direction of the flange plate;

the second lock piece comprises a driving stator and first to fourth rectangular piezoelectric elements;

the driving stator is a cuboid and comprises a first end face, a second end face and first to fourth side faces, wherein the first end face and the second end face are square, the first to fourth side faces are sequentially connected, the first side face is parallel to the third side face, and the second side face is parallel to the fourth side face; the driving stator is provided with a threaded through hole matched with the stud of the threaded lock rod along the axis;

the first end face is provided with a plurality of threaded holes for fixing the second locking piece;

the first to fourth rectangular piezoelectric elements are arranged on the first to fourth side surfaces of the driving stator in a one-to-one correspondence manner;

the length of the threaded through hole of the driving stator is smaller than that of the threaded lock rod light column, the length of the threaded pipe is larger than that of the threaded lock rod stud, and the length difference of the threaded pipe and the threaded lock rod stud is larger than that of the threaded through hole of the driving stator and that of the threaded lock rod light column;

the first to fourth annular piezoelectric elements are polarized along the thickness direction of the first to fourth annular piezoelectric elements, two partitions are divided along the diameter of the first to fourth annular piezoelectric elements as dividing lines, and the polarization directions of the two partitions are opposite; the partition boundaries of the first annular piezoelectric element and the second annular piezoelectric element are parallel, and the polarization directions of the partitions at the same side are opposite; the partition boundaries of the third annular piezoelectric element and the second annular piezoelectric element are perpendicular to each other; the partition boundaries of the fourth annular piezoelectric element and the third annular piezoelectric element are parallel, and the polarization directions of the partitions at the same side are opposite;

the first rectangular piezoelectric element, the second rectangular piezoelectric element and the fourth rectangular piezoelectric element are polarized in the thickness direction of the first rectangular piezoelectric element, the third rectangular piezoelectric element and the fourth rectangular piezoelectric element.

2. The second locking piece driving method based on the joint locking mechanism driven by piezoelectricity according to claim 1, comprising the following steps:

step A.1), a first phase simple harmonic voltage signal is applied to the first rectangular piezoelectric element and the third rectangular piezoelectric element, a second phase simple harmonic voltage signal is applied to the second rectangular piezoelectric element and the fourth rectangular piezoelectric element, a conformal bending vibration mode with a pi/2 phase difference in space of a driving stator is excited, the phase difference of the two phase simple harmonic voltage signals in time is regulated to pi/2, the coupling of the two modes enables a threaded through hole to present rotary bending vibration, and a threaded locking rod is driven to be screwed in or screwed out under the meshing of threads;

and (A.2) if the screw thread locking rod is required to move reversely, adjusting the phase difference of the first and second simple harmonic voltage signals in time to be-pi/2, and driving the screw thread locking rod to move reversely under the meshing of the screw threads by performing opposite rotation bending vibration on the screw thread through hole.

3. The first locking member driving method based on the piezoelectric driving-based joint locking mechanism according to claim 1, comprising the steps of:

step B.1), simultaneously respectively applying two-phase simple harmonic voltage signals to the first electrode plate and the third electrode plate, exciting a conformal bending vibration mode of the threaded pipe with pi/2 phase difference in space, adjusting the phase difference of the two-phase simple harmonic voltage signals in time to pi/2, enabling the threaded pipe to present rotary bending vibration by coupling of the two modes, and driving the threaded locking rod to rotate in or out under the engagement of threads;

and B.2), if the screw thread locking rod is required to move reversely, adjusting the phase difference of the two simple harmonic voltage signals in time to be-pi/2, and driving the screw thread locking rod to move reversely under the meshing of the screw threads by performing opposite rotary bending vibration on the screw thread pipe.

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