JPH01107677A - Ultrasonic wave pulse motor - Google Patents

Abstract

PURPOSE:To heighten torque at a low speed, by setting an oscillator with electrostriction material and the like fitted firmly on the one side surface, and by setting a plate-formed mover in contact with said one side surface. CONSTITUTION:So far as a ring-formed oscillator 1 is concerned, in order to generate the progressive wave of ultrasonic wave oscillation, on the bottom surface, the sheet 2 of electrostriction material or magnetostriction material is fixed in contact with each other. Besides, the metallic disc 3 of a mover pressure-welded on the upper surface of the oscillator 1, an encoder 4 for detecting rotation, and a detection head 5 are arranged. Then, to said electrostriction material or magnetostriction material, according to command signal, the ultrasonic wave signal of half a cycle (one cycle) for output generated from a high-frequency power source having a phase difference or a multi-phase AC power source is applied from a driving electric circuit. As a result, by the ultrasonic wave progressive-wave generated on the oscillator 1, the mover 3 is frictionally driven.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an ultrasonic pulse motor.

[Prior art and problems]

Conventional pulse motors control the excitation of the stator in pulses, thereby applying the rotation of the rotating rotor to a screw shaft, converting it into a linear step motion, and using it for table control AV of a machine tool.

However, this conventional motor requires a conversion mechanism such as a screw shaft to convert rotation into linear motion, resulting in a large drive device and the disadvantage of causing feed errors due to play in the attached motion conversion section. . In addition, conventional motors were unable to produce high torque at low speeds and had low response characteristics.

[Means for solving problems]

The present invention was invented to eliminate such drawbacks, and includes a disk or ring-shaped vibrating body having an electrostrictive material or magnetostrictive material fixed to one side, and a plate-shaped movable body on one side of the vibrating body. A drive circuit that is provided in contact with the body and applies a half-cycle or one-cycle ultrasonic signal output from a high-frequency power source or a multiphase AC power source that adjusts the phase difference to the electrostrictive material or magnetostrictive material according to a command signal. It is characterized by the following.

(Example〕 The present invention will be explained below with reference to an embodiment of the drawings.

In FIG. 1, reference numeral 1 denotes an annular vibrating body, and a thin plate 2 of electrostrictive material or magnetostrictive material is fixedly attached to the bottom surface of the vibrating body in order to generate a traveling wave of ultrasonic vibration. 3 is a disk, annular plate, etc. made of a metal, plastic snack, or composite material of metal and plastic, which is a moving body pressed against the top surface of the vibrating body 1, and 4 is an encoder for detecting the rotation of this moving body disk. It is fixed coaxially to the movable body 3, and a detection head 5 is provided facing the circumference.

Figure 2 is a perspective view of the vibrating body 1. The base material is made of a nickel-iron alloy cap metal or a composite material made by mixing and dispersing nickel powder in a heat-resistant resin. A comb-like notch 1a is formed in the vertical direction to avoid mechanical stiffness and increase the amplitude, and the movable body 3 is pressed against the upper surface of the notch 1a. The contact gap has wear resistance and I! In order to increase the JrM effect, it is recommended to form a coating layer of hard material, and since the movable body 3 is driven by the frictional force of the contact surface with the vibrating body 1, the am coefficient can be used to increase the holding torque and driving torque. It is supposed to be made of a material with high viscosity, or a coating layer of a friction material or an adhesive layer is formed.

FIG. 3 is a front view of the electrostrictive material 2 fixed to one side of the vibrating body 1. Each divided portion of the electrostrictive material 2 is polarized in the + and - directions and provided with electrodes A, B, and S. .

Electrodes A and 8 are provided on the circumference at positions separated by λ/41 of the wavelength of the traveling wave, and are each connected to a high frequency power source E+ having a phase difference of 90°.
, connect Ez. The phase of the traveling wave is detected from the electrode S.

FIG. 4 is a driving electric circuit diagram for applying an ultrasonic signal to an electrostrictive material electrode, and is controlled by a microcomputer CPtJ6. 7 is a high frequency oscillator, 8 is a 90° phase shifter, 9 is an AND gate, 10 is an exclusive OR, 11.12 is an output amplifier, 13 is an input circuit that inputs the position detection signal of the encoder to terminal E, and 14 is an S electrode. Detection signal phase shifter, 1
5 is a phase comparator of an octupole and an S electrode. The high frequency signal oscillated by the programmable oscillator 7 is passed through an AND gate 9,
The signal is supplied to the A'l pole through the amplifier 11, and the phase difference is controlled by the 90° phase shifter 8. The signal passes through the direction switching signal output from the 8 terminals of the CPU 6 and the exclusive OR gate 10, and is then connected to the gate 9 and The energy is supplied to the S electrode through the amplifier 11, and an ultrasonic traveling wave is generated in the S8 body 1 by excitation of the A and S electrodes. Gate 9 has CPU6
A command signal for driving permission is generated from the C terminal of the motor, and can be controlled pulse by pulse.

Further, the phase of the traveling wave detected from the S electrode due to the piezoelectric effect is compared with the A electrode signal by a comparator 15 and input to CF)U6. Thereby, the CPU 6 controls the speed by changing the phase of the oscillator 1 according to the target speed so that the phase difference between A and S becomes a certain value. Of course, the speed can be controlled by changing the excitation voltage of the electrostrictive material. Further, the amount of movement of the moving body 3 is detected by the encoder 5, and inputted from the signal input circuit 13 to the CPU 6, and the CPU controls the command signal output from the terminal C accordingly. The encoder 5 can also detect the speed, which allows the CPU to control the speed.

Also, when a direction switching signal is output from the 8m element of the CP IJ, a phase difference signal of 270° is added to the electrode 8 and the moving direction can be reversed υJIB.

Note that these control circuits can be miniaturized using 13i-CMO8 semiconductor technology, and a small motor can be constructed.

As described above, an ultrasonic signal with a phase difference of 90° is applied to the electrostrictive material 2 fixed to the 1G moving object 1 to the electrodes A and 8, and as a result, the electrostrictive material 2 is polarized as shown in FIG. , when the electric field direction and polarization are the same, they extend in the thickness direction, and when they are opposite, they contract, but since they are arranged so that the polarization direction is alternately reversed, the If polarity generates a standing wave according to the arrangement, and A standing wave with a phase difference of 90'' is also generated by the B electrode which is shifted by 90'' in position, and both standing waves overlap to generate a traveling wave. The traveling wave is generated so as to circulate in the annular vibrating body 1, and rotates the movable body 3, which is in pressure contact with the upper surface of the photographing body, by friction. This is because the annular vibrating body 1 bends and vibrates by controlling the excitation of the electrostrictive material 2. In other words, two standing waves overlap with each other due to a high-frequency electric field with a temporal phase difference of 90 degrees, and move in one direction over time. Traveling wave bending imaging occurs, and the traveling wave circulates through the vibrating body ring 1, but since the vibrating body 1 is a soft comb with cuts 1a formed in the vertical direction, the vibration amplitude in the circumferential direction and the upper limit vertical direction is small. increases, and the movable body 3 that comes into frictional contact with the movable body 3 begins to move and rotate riding on the traveling wave of this bending vibration. The rotation angle is pulse-controlled according to the number of commands from the CPU 6, and by controlling the number of commands according to the detection by the encoder, the target movement range can be precisely controlled.

For example, using PZTffi strain material, the frequency is 40KH2
When driven by applying an AC half-cycle signal with a phase difference of 190°, the moving body in pressure contact with the annular vibrating body has a radius s tm
Approximately 2.5μ per pulse signal in the part, 12560
We were able to perform pulse control to make one rotation with a pulse.

It should be noted that the electrostrictive material 2 may be provided with electrodes to which ten poles are applied alternately to the electrostrictive material polarized in the same polarity, and connected to these electrodes so that both poles of the high frequency power source are applied alternately. can. Furthermore, the polarization and high frequency excitation of the electrostrictive material can be changed by increasing or decreasing the number of electrodes, and the electrostrictive materials can be stacked to generate two standing waves.

Further, an ultrasonic signal may be applied to the electrostrictive material by a multi-phase power source, for example, a three-phase power source with a phase difference of 120°, etc., and a magnetostrictive material may be used as an ultrasonic vibrator and an ultrasonic magnetic field is applied to vibrate it. Can be done.

Further, in the case of the above embodiment, the electrostrictive material (or magnetostrictive material) 2 was fixed to the vibrating body 1 by adhesion, but it is also possible to sinter and form the material integrally. For example, in the main vibrating body part, heat-resistant resin such as imide resin may be used alone, or metal or ceramic particles may be used to improve vibration propagation.
It is filled with a composite resin in which fibers are mixed and dispersed, and the electrostrictive material part is filled with PZTSPLZT, PVDF, and Ti.
A mixture of raw material powder such as 2033a and resin is filled, and the mixture is sintered and formed into one piece. Sintering uses a sintering cap that is energized for a short time. The electrostrictive material has a strong polarization effect when energized, and it is easy to obtain an electrostrictive material with improved electrostrictive effect. In sintering electrostrictive material, 40 vo 1% of PVDF and 60 vo of imide resin
When a 1% mixture is sintered at 230℃ for 5 minutes, 5G
The impact generated a voltage of approximately 5V. About 0 with the conventional one
．． The voltage was 0.01 to 0.02 V, which indicates that the short-time current sintering has a high polarization effect.

Incidentally, each part may be molded by powder sintering mainly made of metal or ceramic material instead of using resin as a whole.

In FIG. 5, a long plate 16 is provided as a movable body by friction welding to a part of the annular moving body 1, and the long plate 1G is moved in a straight line in the length direction by the ultrasonic traveling wave generated in the annular moving body 1. In this embodiment, the excitation of the electrostrictive material fixed to the vibrating body 1 can be controlled in a pulsed manner by controlling the excitation of the electrostrictive material fixed to the vibrating body 1 using a driving circuit as shown in FIG. Detection may be performed using an encoder, and precise program control can be performed by feeding back this detection signal. The elongated plate 16 can be controlled to move left and right by switching the moving direction of the traveling wave generated in the vibrating body 1.

FIG. 6 shows an embodiment in which the linear drive motor shown in FIG. 5 is used in a moving table of a machine tool, etc. 17 is an annular vibrating body fixed to the bed 21, 18 is a long plate movable body, As shown in Figure 5, a moving body 18 is attached to a part of the vibrating body. ! They rub against each other and are driven in the left and right X-axes. 19 is an annular vibrating body fixed to the long plate 18, and 20 is a long plate moving body that is in pressure contact with the vibrating body 19 and is driven in the Y axis perpendicular to the plane of the paper. 23 is the long plate 2
A workpiece 24 is mounted and supported on a moving table fixed at zero. Reference numeral 22 denotes a pad for supporting the movable base, which is fixed to the movable base 23 and connects the bed 21 on the lower surface. Note that both ends of the elongated plate 18 are supported by bearings so that the pad 22 can freely move at right angles to the plane of the paper.

The traveling wave generated in the vibrating body 17 moves the long plate 18 along the X axis, and the traveling wave generated in the vibrating body 19 moves the long plate 20 along the Y axis, and the moving table 23 moves along the X and Y axes. The drive is controlled. In addition, the vibrating body 17.19 and the moving body 18.2
A clutch is provided for each question, and the clutch is switched when moving on the X-axis and Y-axis! 11t[l. The movable table 23 has a pad 22 interposed between the beds 21, so that the weight of the workpiece 24 is reduced by the vibrating body 17.
19 and the movable body elongated plates 18 and 20, there is no change in the contact pressure between them, and motor drive control can be performed by applying a constant wm force. In addition, since the vibrating body 17 and 19 and the movable long plate 18 and 20 do not have screw shafts for conventional rotation-linear conversion, the long plate can freely move with a predetermined friction force when the vibrating body is not energized. It is convenient that the movable stage 23 with the workpiece 24 mounted thereon can be freely moved manually to control the positioning at any point on the XY plane.

FIG. 7 shows an embodiment in which the driving force of the elongated movable body of the embodiment shown in FIG. Both long plates 16 and 25 are connected by a link 26. According to this, the long plates 16, 25 are rubbed by the traveling waves in the direction circulating in the vibrating body 1.
are driven at the same time, and the movement of the elongated plate 25 is applied in the moving direction of the elongated plate 16 through the link 26, so that the elongated plate 16 can be moved with twice the driving force. When using this for table control as shown in FIG.
It may be fixed to

In addition, in order to give rotation to the movable body base 23 in FIG. 6, a disk or annular plate 3 is attached to the photographing body 1 as shown in FIG. It is only necessary to provide an ultrasonic motor that is brought into frictional contact with the motor, and movement control can be performed using any combination of X-axis, Y-axis drive, rotational drive, etc.

FIG. 8 shows another embodiment in which a rectangular ring-shaped vibrating body 21 is mounted on both upper and lower surfaces of a long plate 16. A long plate 1 is provided in frictional contact with the electrostrictive material 28 provided on the inner wall surface and is excited by a phase difference ^ frequency power source to generate an ultrasonic traveling wave that penetrates the ring w1 and is pressed into contact with the electrostrictive material 28.
6 is linearly driven. Although the driving force of the elongated plate 16 is doubled by the traveling wave generated in the vertical moving body 27 by providing it as shown in the figure, it is also possible to drive only one of the vibrating bodies 27.

FIG. 9 shows a vibrating body 29 formed of the rectangular annular vibrating body shown in FIG. It is. By controlling the excitation of the electrostrictive material 30, a surface wave (Rayleigh wave) of an ultrasonic traveling wave is generated that circulates on the surface of the vibrating body 29, thereby linearly driving the elongated plate 16 in contact with the surface.

FIG. 10 shows a rod-shaped moving body 33 on the top surface of a long annular vibrating body 31.
．． 1'! due to the traveling wave generated in the vibrating body by shaking 34!
! ! It is designed to be driven and moved in a straight line. The side surface is as shown in FIG. 11, with electrostrictive material 32 on the bottom of the vibrating body 31.
Glue and excite.

〔Effect of the invention〕

According to the present invention as described above, a disk or ring shape (circular ring, rectangular ring, etc.) with an electrostrictive material or magnetostrictive material fixed to one side can be obtained.
A moving body is provided, a moving body in the form of a plate (disc, annular plate, elongated plate, etc.) is provided in contact with one side of the vibrating body, and a phase difference is applied to the electrostrictive material or magnetostrictive material according to a command signal. The device is equipped with a drive electric circuit that applies a half-cycle or one-cycle ultrasonic signal output from a high-frequency electromagnetic or multiphase AC Fl power source, so that the moving body is frictionally driven by the ultrasonic traveling waves generated in the vibrating body. As a result, high torque can be obtained at low speeds, the structure is simple and compact, high response control is possible, and position control can be performed easily and accurately by pulse control of ultrasonic vibration.

In addition, when a long plate is provided on a moving body driven by an ultrasonic traveling wave of an annular or rectangular imaging body and the moving body is driven in a straight line, the screw shaft etc. for rotation-direction motion conversion is removed and the linear motion is performed. It can be taken out directly, the configuration of the feeding device is simple and compact, and accurate linear feeding control can be provided.

Further, an encoder is provided to detect the moving position or the moving position and speed of the moving body, and a high frequency power source or a multiphase AC power source having a phase difference is outputted to the electrostrictive material or magnetostrictive material in accordance with a command signal based on the detection by the encoder. By providing a driving electric circuit that applies a half-cycle or one-cycle ultrasonic signal, it is possible to control the position and feed speed by the pulse motor very accurately.

Further, as an application example of the pulse motor, the vibrating body is fixed to a fixed part, the moving body is fixed to a moving body such as a feeding device, and a movable pad is provided between the moving part and the fixed part. Therefore, the contact pressure between the imaging body and the movable body can be maintained constant, the frictional force can be kept constant, and the pulse drive of the motor can be controlled stably and precisely.

In addition, the feeding device for the machining table of a machine tool equipped with this ultrasonic pulse motor has no screws, etc. when the vibrating body is not excited, and can be freely slid between the photographing body and the moving body, and can be moved freely by hand. Feed positioning control can be performed.

[Brief explanation of the drawing]

FIG. 1 is a side view of one embodiment of the present invention, FIG. 2 is a perspective view of a portion thereof, FIG. 3 is a bottom front view thereof, FIG. 4 is a driving electric circuit diagram thereof, and FIGS. 5 to 11. The figure shows another embodiment. 1... Vibrating body 2... Electrostrictive material 3... Moving body 4... Encoder patent Applicant: Kiyoshi Inoue, Representative of Inoue Zipax Laboratory Co., Ltd.

Claims (3)

[Claims] (1) A disc or ring-shaped vibrating body having an electrostrictive material or magnetostrictive material fixed to one side is provided, a plate-shaped moving body is provided in contact with one side of the vibrating body, and the electrostrictive material or magnetostrictive material is An ultrasonic pulse motor characterized by being provided with a drive electric circuit that applies a half-cycle or one-cycle ultrasonic signal output from a high-frequency power source or a multiphase AC power source having a phase difference in accordance with a command signal. (2) A disc or ring-shaped vibrating body having an electrostrictive material or magnetostrictive material fixed to one side is provided, a plate-shaped moving body is provided in contact with one side of the vibrating body, and the moving position or movement of the moving body is An encoder for detecting position and velocity is provided, and a half cycle or one cycle of ultrasonic waves is output from a high frequency power source or a multiphase AC power source having a phase difference according to a command signal detected by the encoder to the electrostrictive material or magnetostrictive material. An ultrasonic pulse motor characterized by comprising a drive electric circuit that applies a signal. (3) A disc or ring-shaped vibrating body with an electrostrictive material or magnetostrictive material fixed to one side is provided, a plate-shaped moving body is provided in contact with one side of the vibrating body, and the vibrating body is fixed to a fixed part. At the same time, the movable body is fixed to a movable part, a spacer is movably provided between the movable part and the fixed part, and the electrostrictive material or the magnetostrictive material is provided with a high frequency power source or a high frequency power source having a phase difference according to a command signal. An ultrasonic pulse motor characterized by being provided with a driving electric circuit that applies a half-cycle or one-cycle ultrasonic signal output from a multiphase AC power source.