Piezoelectric multi-degree-of-freedom actuator based on variable modal resonance driving
Technical Field
The invention relates to a piezoelectric multi-degree-of-freedom actuator, in particular to a piezoelectric multi-degree-of-freedom actuator driven by variable modal resonance.
Background
At present, the piezoelectric actuator utilizes the inverse piezoelectric effect of the piezoelectric material to electrify the piezoelectric material to generate displacement output, thereby realizing mechanical movement. The piezoelectric driver has the characteristics of high sensitivity, quick response, simple structure, no electromagnetic interference and the like, and is an effective means for realizing precise movement and control. The fields of precision instruments and the like often require a driving device with high precision and multiple degrees of freedom motion. The traditional electromagnetic, hydraulic and other drivers are difficult to meet the requirement of precise movement.
The traditional piezoelectric driver mostly outputs in a single degree of freedom, and can only realize linear motion output along one direction or rotary output around a fixed shaft, so that complex working scenes are difficult to deal with, and the application space is limited. However, the conventional multi-degree-of-freedom piezoelectric driving device generally needs a plurality of piezoelectric drivers connected in series, and has large occupied space and complicated structure. In addition, the output generated by the conventional driver under the same power input condition is a certain value, and thus, the conventional driver is difficult to cope with a complex working environment. Therefore, the precise driving device with high space utilization rate, variable frequency output and multiple-degree-of-freedom output function can realize linear vibration output and swinging output around a spherical fulcrum.
Disclosure of Invention
The invention provides a piezoelectric multi-degree-of-freedom actuator based on variable mode resonance driving, which aims to solve the problems that the traditional piezoelectric actuator mostly outputs in a single degree of freedom, can only realize linear motion output along one direction or rotation output around a fixed shaft and is difficult to cope with complex working scenes.
The invention provides a piezoelectric multi-degree-of-freedom actuator based on variable modal resonance driving, which comprises a driving disc, a shell, a base, a driving mechanism and a piezoelectric wafer, wherein the shell is assembled on the base, the driving disc is arranged at the top end of the shell, the driving mechanism and the piezoelectric wafer are integrated in an inner cavity of the shell, the piezoelectric wafer is connected with the driving mechanism, and the piezoelectric wafer drives the driving disc to do up-down rectilinear motion and swing at any angle and direction through the driving mechanism.
The center part of the bottom of the driving disc is hinged on the spherical hinge through a hinge head cap, the driving disc can swing at any angle on the spherical hinge, a straight rod at the lower part of the spherical hinge head is in threaded connection with a connecting shaft at the lower part of the spherical hinge head, the straight rod at the lower part of the spherical hinge head is sleeved with the hinge head seat, the hinge head seat is wrapped at the lower part of the spherical hinge head, the connecting shaft at the lower part of the spherical hinge head is inserted in a center hole of a fixed seat at the center part of the chassis of the shell, and the connecting shaft can slide in the center hole of the fixed seat.
The bottom of driving disk is provided with crisscross slide that intersects, and the first slider joint on the actuating mechanism can slide along the slide on the slide.
The driving mechanism comprises a first sliding block and a driving rod, wherein the first sliding block is assembled at the top end of the driving rod, the first sliding block is clamped on a slideway at the bottom of the driving disk, the bottom of the driving rod is fixedly connected onto a piezoelectric wafer, and the driving rod can drive the first sliding block to slide along the slideway at the bottom of the driving disk due to vibration of the piezoelectric wafer.
The piezoelectric wafers are assembled with four pieces, every two of the four pieces of piezoelectric wafers are arranged in a crossed mode, the crossed piezoelectric wafers correspond to the crossed slideway at the bottom of the driving disc, the inner ends of the four pieces of piezoelectric wafers are fixedly connected to the fixed seat at the center of the chassis of the shell, the outer ends of the four pieces of piezoelectric wafers are fixedly connected with the driving rod on the driving mechanism, and the driving rod on the driving mechanism corresponds to the piezoelectric wafers and is also assembled with four pieces of piezoelectric wafers.
And the position of each piezoelectric wafer close to the fixed seat is provided with an adjusting groove, a variable-frequency screw is assembled in the adjusting groove, and the natural frequency of the piezoelectric wafer is adjusted by increasing or decreasing the number of the variable-frequency screws and adjusting the position of the variable-frequency screw in the adjusting groove.
Every piezoelectric wafer is last to be overlapped and is equipped with the second slider, the spout has been seted up to the position department that corresponds the second slider on the chassis of casing, the second slider can slide on piezoelectric wafer and in the spout, the bottom of second slider is provided with the connecting rod, the outer end of connecting rod links firmly on the elevating platform, the elevating platform cover is established on the slide shaft, the elevating platform can reciprocate on the slide shaft, thereby the elevating platform is on the slide shaft reciprocate and drive the second slider and slide on piezoelectric wafer and in the spout through the connecting rod and change the position of second slider on piezoelectric wafer, the top of slide shaft links firmly on the fixing base bottom surface of casing chassis middle part, be equipped with adjusting nut on the slide shaft of elevating platform bottom, can adjust the settlement position of elevating platform on the slide shaft through adjusting nut, be equipped with the spacing that the spacing ring is used for adjusting nut on the slide shaft of adjusting nut lower part.
The working principle of the invention is as follows:
the piezoelectric multi-degree-of-freedom actuator based on variable modal resonance driving provided by the invention supplies power to the piezoelectric wafer through the power supply when in use, adjusts the frequency, amplitude, vibration mode and the like of the power supply to adjust the displacement of the piezoelectric wafer, and transmits the displacement of the piezoelectric wafer to the driving disc through the driving rod at the outer end of the piezoelectric wafer after the amplification of the lever fulcrum of the second sliding block sleeved on the piezoelectric wafer, thereby achieving the purpose of controlling the displacement of the actuator. The motion mode of the phase control actuator of the power supply is adjusted, so that vertical linear vibration and swinging motion around any angle of the spherical hinge head can be respectively realized, and simultaneous superposition output of the two motions can be realized. Meanwhile, the four piezoelectric wafers can realize clamping of motion, and still have higher holding force in a power-down state.
Each piezoelectric wafer is provided with an adjusting groove for changing the mass of the piezoelectric wafer, the mass of the system is increased or decreased by increasing or decreasing the variable frequency screw, and the position of the variable frequency screw in the adjusting groove is adjusted to change the natural frequency of the piezoelectric wafer.
The driving disc is connected to the spherical hinge head, so that the driving disc can realize linear vibration, swing around any angle of the spherical hinge head, and play a role in occasions needing angle positioning (such as lens deflection angle control).
Four piezoelectric wafers are distributed in a symmetrical cross mode in pairs, each piezoelectric wafer is independently powered, and vibration can be generated by the piezoelectric wafers when alternating current is applied to the piezoelectric wafers due to the inverse piezoelectric effect, so that vibration displacement of the piezoelectric wafers can be conducted to a driving disc according to a certain amplification proportion, and a driving function is achieved. The displacement amplification function is realized by the second sliding block, the displacement amplification proportion can be adjusted by adjusting the position of the lifting table, and meanwhile, the natural frequency of the piezoelectric wafer can be changed by adding a variable-frequency screw rod to be matched.
The specific working process is as follows:
linear displacement: when the amplitude, frequency and phase of the alternating power supply of the four piezoelectric wafers are the same, the displacement modes of the four piezoelectric wafers are the same, so that the same displacement is conducted on the driving rod, and the driving disc moves linearly up and down. The displacement of the driving disc can be controlled by adjusting the power supply mode.
Swing displacement: the gesture of driving disk in three-dimensional space is controlled by four slide cooperation pairs, and the electricity of two relative piezoelectric wafers of control position is if phase difference T/2 (T is alternating power supply vibration's minimum positive cycle), and other parameters are the same, and the displacement direction of piezoelectric wafer is opposite, so the driving disk can incline to the actuating lever direction that the displacement direction is down, and the same reason is adjusted two other relative piezoelectric wafer power simultaneously, can adjust the inclination of driving disk in another direction to can realize the swing of the arbitrary angle of drive coiling spherical hinge head.
The invention has the beneficial effects that:
the piezoelectric multi-degree-of-freedom actuator based on variable modal resonance driving provided by the invention is driven by the piezoelectric wafer and the mechanical structure, the displacement amplification factor of the piezoelectric wafer is precisely controlled, when the amplification factor of the actuator needs to be regulated in the use process, the power supply is stopped, the height of the lifting table is regulated, the sliding of the lever fulcrum on the sliding groove of the chassis of the shell can be realized, namely, the proportion of the displacement amplification of the outer end of the piezoelectric wafer can be changed, and the regulating device is arranged at the opening below the chassis of the shell and can be directly contacted, so that the piezoelectric multi-degree-of-freedom actuator can be regulated without dismantling the piezoelectric multi-degree-of-freedom actuator.
According to the invention, the vibration frequency of the piezoelectric wafers can be regulated, the regulating grooves for changing the mass of the piezoelectric wafers are reserved on each piezoelectric wafer, the mass of the system is increased or decreased by increasing or decreasing the variable-frequency screw, or the rigidity of the piezoelectric wafers is regulated by changing the position of the variable-frequency screw, so that the vibration frequency of the piezoelectric wafers is regulated.
The driving disc is connected to the spherical hinge head, so that linear vibration can be realized, swing around any angle of the spherical hinge head can be realized, and the driving disc can play a role in occasions needing angle positioning (such as lens deflection angle control).
Drawings
Fig. 1 is a schematic diagram of the overall structure of the piezoelectric multi-degree-of-freedom actuator according to the present invention.
Fig. 2 is a bottom view of the overall internal structure of the piezoelectric multiple degree of freedom actuator according to the present invention.
Fig. 3 is a front view of the overall internal structure of the piezoelectric multi-degree of freedom actuator according to the present invention.
Fig. 4 is a schematic diagram of an explosion structure of the piezoelectric multi-degree-of-freedom actuator according to the present invention.
Fig. 5 is a schematic view of an assembly structure of a piezoelectric wafer according to the present invention.
Fig. 6 is a schematic view of the bottom structure of the driving disc according to the present invention.
Fig. 7 is a schematic view of a chassis structure of a housing according to the present invention.
Fig. 8 is a schematic view of a piezoelectric wafer according to the present invention.
Fig. 9 is a schematic diagram of a driving disc turnover control principle according to the present invention.
Fig. 10 is a schematic diagram of the principle of the magnification change of the actuator according to the present invention.
Fig. 11 is a schematic diagram of the principle of fulcrum change magnification according to the present invention.
The labels in the above figures are as follows:
1. drive disc 2, housing 3, base 4, piezoelectric chip 5, head-reaming cap 6, spherical head-reaming
7. Connecting shaft 8, hinge seat 9, fixing seat 10, slideway 11 and first sliding block
12. Drive rod 13, adjusting groove 14, variable frequency screw 15, second slider 16, spout
17. Connecting rod 18, lifting table 19, sliding shaft 20, chassis 21 and adjusting nut
22. And a limiting ring.
Detailed Description
Please refer to fig. 1 to 11:
the invention provides a piezoelectric multi-degree-of-freedom actuator based on variable modal resonance driving, which comprises a driving disc 1, a shell 2, a base 3, a driving mechanism and a piezoelectric wafer 4, wherein the shell 2 is assembled on the base 3, the driving disc 1 is arranged at the top end of the shell 2, the driving mechanism and the piezoelectric wafer 4 are integrated in an inner cavity of the shell 2, the piezoelectric wafer 4 is connected with the driving mechanism, and the piezoelectric wafer 4 drives the driving disc 1 to perform vertical linear motion and swing at any angle and direction through the driving mechanism.
The center part of the bottom of the driving disc 1 is hinged on the spherical hinge head 6 through the hinge head cap 5, the driving disc 1 can swing at any angle on the spherical hinge head 6, a straight rod at the lower part of the spherical hinge head 6 is in threaded connection with a connecting shaft 7 at the lower part, a hinge head seat 8 is sleeved on the straight rod at the lower part of the spherical hinge head 6, the hinge head seat 8 is wrapped on the lower part of the spherical hinge head 6, the connecting shaft 7 at the lower part of the spherical hinge head 6 is inserted in a center hole of a fixed seat 9 at the center part of a chassis 20 of the shell 2, and the connecting shaft 7 can slide in the center hole of the fixed seat 9.
The bottom of the driving disk 1 is provided with a cross-shaped crossed slideway 10, a first sliding block 11 on the driving mechanism is clamped on the slideway 10, and the first sliding block 11 can slide along the slideway 10.
The driving mechanism comprises a first sliding block 11 and a driving rod 12, wherein the first sliding block 11 is assembled at the top end of the driving rod 12, the first sliding block 11 is clamped on a slideway 10 at the bottom of the driving disc 1, the bottom of the driving rod 12 is fixedly connected to the piezoelectric wafer 4, and the driving rod 12 can drive the first sliding block 11 to slide along the slideway 10 at the bottom of the driving disc 1 due to vibration of the piezoelectric wafer 4.
The piezoelectric wafers 4 are assembled with four pieces, every two of the four pieces of piezoelectric wafers 4 are arranged in a crossed mode, the crossed piezoelectric wafers 4 correspond to a crossed slideway 10 at the bottom of the driving disc 1, the inner ends of the four pieces of piezoelectric wafers 4 are fixedly connected to a fixed seat 9 at the center of a chassis 20 of the shell 2, the outer ends of the four pieces of piezoelectric wafers 4 are fixedly connected with a driving rod 12 on a driving mechanism, and the driving rod 12 on the driving mechanism corresponds to the piezoelectric wafers 4 and is also assembled with four pieces.
An adjusting groove 13 is formed in the position, close to the fixing seat 9, of each piezoelectric wafer 4, a variable-frequency screw 14 is assembled in the adjusting groove 13, and the natural frequency of the piezoelectric wafer 4 is adjusted by increasing or decreasing the number of the variable-frequency screws 14 and adjusting the positions of the variable-frequency screws 14 in the adjusting groove 13.
Each piezoelectric wafer 4 is sleeved with a second sliding block 15, a sliding groove 16 is formed in a chassis 20 of the shell 2 at a position corresponding to the second sliding block 15, the second sliding block 15 can slide on the piezoelectric wafers 4 and in the sliding groove 16, a connecting rod 17 is arranged at the bottom of the second sliding block 15, the outer end of the connecting rod 17 is fixedly connected to a lifting table 18, the lifting table 18 is sleeved on a sliding shaft 19, the lifting table 18 can move up and down on the sliding shaft 19, the lifting table 18 moves up and down on the sliding shaft 19 to drive the second sliding block 15 to slide on the piezoelectric wafers 4 and in the sliding groove 16 through the connecting rod 17, so that the position of the second sliding block 15 on the piezoelectric wafers 4 is changed, the top end of the sliding shaft 19 is fixedly connected to the bottom surface of a fixed seat 9 in the middle of the chassis 20 of the shell 2, an adjusting nut 21 is arranged on the sliding shaft 19 at the bottom of the lifting table 18, the setting position of the lifting table 18 on the sliding shaft 19 can be adjusted through the adjusting nut 21, and a limiting ring 22 is arranged on the sliding shaft 19 at the lower part of the adjusting nut 21 for limiting the adjusting nut 21.
The working principle of the invention is as follows:
the piezoelectric multi-degree-of-freedom actuator based on variable modal resonance driving provided by the invention supplies power to the piezoelectric wafer 4 through the power supply when in use, adjusts the frequency, amplitude, vibration mode and the like of the power supply to adjust the displacement of the piezoelectric wafer 4, and the displacement of the piezoelectric wafer 4 is transmitted to the driving disc 1 through the driving rod 12 at the outer end of the piezoelectric wafer 4 after the amplification of the lever fulcrum of the second sliding block 15 sleeved on the piezoelectric wafer 4, thereby achieving the purpose of controlling the displacement of the actuator. The motion mode of the phase control actuator of the power supply is adjusted, so that vertical linear vibration and swinging motion around the spherical hinge head 6 at any angle can be respectively realized, and simultaneous superposition output of the two motions can be realized. Meanwhile, the four piezoelectric wafers 4 can realize clamping of motion, and still have higher holding force in a power-down state.
Each piezoelectric wafer 4 is provided with an adjusting groove 13 for changing the mass of the piezoelectric wafer 4, the mass of the system is increased or decreased by increasing or decreasing the variable frequency screw 14, and the position of the variable frequency screw 14 in the adjusting groove 13 is adjusted to change the natural frequency of the piezoelectric wafer 4.
The driving disc 1 is connected to the spherical hinge head 6, so that the driving disc 1 can realize linear vibration, swing around any angle of the spherical hinge head 6, and play a role in occasions requiring angular positioning (such as lens deflection angle control).
The four piezoelectric wafers 4 are distributed in a symmetrical cross mode in pairs, each piezoelectric wafer 4 is independently powered, and due to the inverse piezoelectric effect, the piezoelectric wafers 4 vibrate when alternating current is applied to the piezoelectric wafers 4, and vibration displacement of the piezoelectric wafers 4 can be conducted to the driving disc 1 according to a certain amplification proportion, so that a driving function is achieved. The displacement amplification function is realized by the second sliding block 15, the displacement amplification proportion can be adjusted by adjusting the position of the lifting table 18, and meanwhile, the natural frequency of the piezoelectric wafer 4 can be changed by adding the matching pair of the variable-frequency screw 14.
The specific working process is as follows:
linear displacement: when the amplitude, frequency and phase of the alternating power supply of the four piezoelectric wafers 4 are the same, the displacement modes of the four piezoelectric wafers 4 are the same, so that the same displacement is conducted on the driving rod 12, and the driving disc 1 moves linearly up and down. The displacement of the drive disc 1 can be controlled by adjusting the power mode.
Swing displacement: the posture of the driving disc 1 in the three-dimensional space is controlled by four slide ways 10 in a matched mode, the electric phase difference T/2 (T is the minimum positive period of alternating power supply vibration) of two opposite piezoelectric wafers 4 is controlled, the other parameters are identical, the displacement directions of the piezoelectric wafers 4 are opposite, so that the driving disc 1 can incline in the direction of a driving rod 12 with the lower displacement direction, and similarly, the power supply of the other two opposite piezoelectric wafers 4 is adjusted, and the inclination angle of the driving disc 1 in the other direction can be adjusted, so that the driving disc 1 can swing around the spherical hinge head 6 at any angle.