JPH03253268A - Ultrasonic linear motor and slide table using it - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ultrasonic linear motor and a slide table using the same, and in particular, the clutch function, brake function, and bearing function between the slider and the transmission rod. This invention relates to an ultrasonic linear motor equipped with an ultrasonic linear motor and a technique effective when applied to a slide table using the same.

[Prior art] As a conventional ultrasonic linear motor, for example,
9-122385, Japanese Patent Application Laid-Open No. 60-22478, etc., have been proposed that use an ultrasonic motor that utilizes the strong vibrational energy of ultrasonic waves.

Its outline includes, for example, two sets of piezoelectric vibrators excited by the application of a high-frequency voltage, a transmission rod fixed to these two sets of piezoelectric vibrators, and a slider that is brought into pressure contact with the transmission rod. By excitation of one piezoelectric vibrator, an elliptical vibration with a phase shift of 90 degrees is formed on the transmission rod by horizontal vibration and longitudinal vibration, and this elliptical vibration is propagated on the transmission rod as a traveling wave in one direction, and the other is absorbed by the piezoelectric vibrator. Furthermore, this traveling wave is formed in the same way at any point on the transmission rod, and in this state, the slider is contacted only at the peak of the traveling wave, and the friction with the transmission rod creates a thrust force in the opposite direction to the traveling wave on the slider. generated. As a result, the slider is driven in the opposite direction to the traveling wave and converted into rotational or linear motion.

[Problems to be Solved by the Invention] However, in the prior art as described above, since the slider is in pressure contact with the transmission rod, for example, when the application of high frequency voltage to the piezoelectric vibrator is stopped, There is a problem in that the slider becomes self-locked and cannot be moved manually. Therefore, when the switch for applying high frequency voltage to the piezoelectric vibrator is turned off, the slider cannot be freely moved to a predetermined position, which poses problems in terms of adjustment and maintenance.

Therefore, the inventor of the present invention generated a standing wave on the transmission rod by opening the load resistor connected to the piezoelectric vibrator, which absorbs the traveling wave, and drove it over time to spread the entire transmission rod. It was discovered that compared to the traveling wave that contacts the slider, the friction coefficient of the standing wave can be reduced because the contact position with the slider is determined by the wavelength of the transmission rod.

That is, an object of the present invention is to provide an ultrasonic linear motor that is equipped with a clutch function by switching between a traveling wave and a standing wave on a transmission rod, and can generate a braking function and a bearing function between a slider and a transmission rod. and to provide a sliding table using the same.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] Among the inventions disclosed in this application, a brief overview of typical inventions is as follows.

That is, the ultrasonic linear motor of the present invention and the slide table using the same include a first piezoelectric vibrator and a second piezoelectric vibrator excited by application of a high frequency voltage, and the first and gJ2 piezoelectric vibrators. a transmission rod fixed to the
a slider that is brought into pressure contact with the transmission rod;
Alternatively, a traveling wave in one direction is formed on the transmission rod by exciting one of the second piezoelectric vibrators, and the traveling wave is absorbed by the other of the second or first piezoelectric vibrators. an ultrasonic linear motor in which the traveling wave generates a thrust in the opposite direction to the traveling wave in the slider, and the thrust drives the slider in the opposite direction to the traveling wave; A high frequency power source is switchably connected to one of the second piezoelectric simulators, and
Alternatively, a load resistor and an operation switch to which the load resistor is connected or opened are connected in series to the other of the first piezoelectric vibrators, and the first or second piezoelectric vibrator is excited.
A traveling wave is generated on the transmission rod by bringing the load resistance of the second or first piezoelectric vibrator into a connected state, while leaving the load resistance of the second or first piezoelectric vibrator in an open state. thereby generating a standing wave on the transmission rod,
The friction coefficient and wear between the transmission rod and the slider are reduced by the generation of the standing wave, so that the slider can be easily driven manually.

Further, when a high frequency power source is not connected to either the first piezoelectric vibrator or the second piezoelectric vibrator, the slider that is brought into pressure contact with the transmission rod is in a self-locking state. be.

[Function] According to the ultrasonic linear motor and the slide table using the same, the high frequency power source is switchably connected to either the first or second piezoelectric vibrator, and the high frequency power source is switchably connected to either the first or second piezoelectric vibrator. By connecting in series a load resistor and an operation switch to which the load resistor is connected or disconnected to the other piezoelectric vibrator, the first or second piezoelectric vibrator is excited and the second or first piezoelectric vibrator is excited. By connecting the load resistance of the piezoelectric vibrator, a traveling wave can be generated on the transmission rod. Thereby, the slider that is pressed into contact with the transmission rod and the table that is operatively connected to the slider can be driven in a predetermined direction.

On the other hand, by opening the load resistance of the second or first piezoelectric vibrator, a standing wave can be generated on the transmission rod. This can reduce the coefficient of friction and wear between the transmission rod and the slider, so the slider and table can be easily driven manually.

Further, when a high frequency power source is not connected to either the first piezoelectric vibrator or the second piezoelectric vibrator, the slider that is pressed into contact with the transmission rod can be brought into a self-locking state.

[Example] Fig. 1 is a schematic configuration diagram showing a circuit of an ultrasonic linear motor according to an embodiment of the present invention, and Fig. 2 is a plan view showing a slide table using the ultrasonic linear motor of this embodiment. Third
Figures (a) and (b) are explanatory diagrams showing the operation of the ultrasonic linear motor of this embodiment.

First, the configuration of the slide table using the ultrasonic linear motor of this embodiment will be explained with reference to FIG.

The slide table using the ultrasonic linear motor of this embodiment includes, for example, a first piezoelectric vibrator 1 and a second piezoelectric vibrator 2 excited by the application of a high-frequency voltage, and these first and second piezoelectric vibrators. It is composed of a transmission rod 3 fixed to a piezoelectric vibrator 1.2, and a slider 4 brought into pressure contact with the transmission rod 3. A table 5 is sandwiched between the slider 4 in a structurally separate manner, and the table 5 is further guided by a linear guide 6 and linearly driven along the axial direction.

The first and second piezoelectric vibrators 1.2 are, for example, Langevin-type vibrators bolted together from both ends to form a cylindrical shape. are arranged horizontally on the left and right sides of the main body 7, respectively.
The position of the longitudinal vibration node is fixed to the main body 7. and,
It has a structure in which it is excited around a fixed base point by applying a high frequency voltage.

The transmission rod 3 is made of, for example, aluminum and has a prismatic shape, and both ends of the transmission rod 3 are fixed to one ends of the first and second piezoelectric vibrators 1.2, which are arranged horizontally. For example, by excitation of the first piezoelectric vibrator 1 on the oscillation side, a traveling wave that vibrates along the axial direction is formed on the transmission rod 3, and the traveling wave is generated by the second piezoelectric vibrator 2 on the absorption side. It has a structure that allows it to be absorbed.

The slider 4 is made of, for example, aluminum and has a rectangular tube shape. A spring (not shown) is housed inside the slider 4, and the slider 4 is pressed into contact with the transmission rod 3 by the compression force of the spring. The traveling wave formed on the transmission rod 3 generates a thrust in the direction opposite to the traveling wave, and the slider 4 is driven in the opposite direction to the traveling wave.

The table 5 is held in a state where the table 5 is separated in the axial direction by connecting plates 8 disposed at both ends of the slider 4. Further, the table 5 is arranged so that the load direction due to the weight of the table 5 and the payload of the conveyed object placed on the table 5 and the vibration direction of the traveling wave on the transmission rod 3 have a phase difference of 90 degrees. ing. The structure is such that the table 5 is linearly driven along the axial direction in conjunction with the driving of the slider 4 without restricting the driving of the slider 4.

Two linear guides 6 are arranged in parallel along the driving direction of the table 5, and the driving of the table 5 is guided by the two linear guides 6. The structure is such that the table 5 is stably linearly driven while receiving the weight of the table 5 and the payload of the transported object placed on the table 5.

The slide table using the ultrasonic linear motor of the present embodiment configured as described above has jJl and the second piezoelectric vibrator 1.2, a high frequency power source 9, and a changeover switch, for example, as shown in FIG. 10, a load resistor 11 and an operation switch 12 are connected, and the changeover switch 10 switches the drive direction of the slider 4 and table 5 and the disconnection of the high frequency power source 9, and the operation switch 12 switches the self-locking state. ing.

Next, the operation of this embodiment will be explained.

First, the changeover switch 10 is set to the state shown in FIG. 1, that is, a closed circuit in which the high frequency power source 9 is connected to the first piezoelectric vibrator 1, and the applied voltage of the high frequency power source 9 is supplied to the first piezoelectric vibrator 1. . The first piezoelectric vibrator 1 on the oscillation side to which the voltage is applied is excited in the direction of the solid arrow around the base point fixed to the main body 7. At this time, no high frequency voltage is applied to the second piezoelectric vibrator 2, and the load resistor 11 is connected with the operation switch 12 in the closed state.

Furthermore, due to the excitation of the first piezoelectric vibrator 1, a third r! A
A rightward traveling wave is formed by elliptical vibration with a phase shift of 90 degrees due to the transverse vibration and longitudinal vibration as shown in (a), and is absorbed by the second piezoelectric vibrator 2 on the absorption side. Then, the slider 4 that is brought into pressure contact with the transmission rod 3 is driven in the opposite direction to the traveling wave formed on the transmission rod 3, that is, to the left.

As a result, the table 5 held by the slider 4 is guided by the linear guide 6, and is stably linearly driven to the left in conjunction with the drive of the slider 4.

Next, when the changeover switch 10 is changed from the state shown in FIG. 1 to the state shown by the dotted line, that is, when the changeover switch 10 is changed to a closed circuit in which the high frequency power source 9 is connected to the second piezoelectric vibrator 2, contrary to the above, the voltage is changed as described above. is applied to the second piezoelectric vibrator 2 on the oscillation side, a traveling wave is formed on the surface of the transmission rod 3 in the opposite direction to that described above, that is, to the left, and the slider 4, which was being driven to the left, is Driven to the right.

In this way, by switching the changeover switch 10, the slider 4 and the table 5 can be driven along the axial direction of the slide table.
When an object is placed on the table 5, the object can be transported within the drive range of the table 5.

In the ultrasonic linear motor driven as described above,
For example, when the changeover switch 10 is in a neutral state, that is, when the high frequency power source 9 is not connected to both the first piezoelectric vibrator 1 and the second piezoelectric vibrator 2, the slider 4 that is pressed into contact with the transmission rod 3 is self-selecting. It becomes locked and the slider 4 cannot be moved manually. Therefore, by turning off the changeover switch 10, the transmission rod 3 and slider 4 are
A brake function can be generated between the

In this case, the selector switch 10 can be set to either the first piezoelectric vibrator 1 or the second piezoelectric vibrator 2, for example! !
A closed circuit is formed in which a high frequency power source 9 is connected to the piezoelectric vibrator 1 of 1, and the closed operation switch 12 is opened to set the load resistor 11 to an open state, that is, infinite, and place it on the transmission rod 3 as shown in FIG. 3(b). Generates a standing wave like . This results in
The friction coefficient between the transmission rod 3 and the slider 4 becomes extremely small due to the longitudinal vibration of the generated standing wave, and since the standing wave has no transverse vibration, that is, no resistance corresponding to xi, wear can be reduced. Therefore, an ultrasonic linear bearing function can be generated between the transmission rod 3 and the slider 4.

Therefore, according to the ultrasonic linear motor of this embodiment and the slide table using the same, the high frequency power source 9 is connected to either the first or second piezoelectric vibrator 1.2, and the high frequency power source 9 is connected to either the first or second piezoelectric vibrator 1.2. By connecting in series the load resistor 11 and the operation switch 12 to which the load resistor 11 is connected or opened to the other piezoelectric vibrator 2.1, the first piezoelectric vibrator 1 can be brought into an excited state, for example. By connecting the load resistor 11 to the second piezoelectric vibrator 2, a traveling wave can be generated on the transmission rod 3, and the slider 4 and table 5 can be driven in a predetermined direction.

On the other hand, by opening the load resistance 11 of the second piezoelectric vibrator 2, a standing wave is generated on the transmission rod 3, and the friction coefficient and wear between the transmission rod 3 and the slider 4 are reduced. Therefore, the slider 4 and table 5 can be manually driven using the ultrasonic linear bearing function.

Furthermore, when the changeover switch 10 is in the disconnected state, that is, when the high frequency power source 9 is not connected to both the first and second piezoelectric vibrators 1.2, the slider 4, which is brought into pressure contact with the transmission rod 3, is in a self-locking state. Therefore, a braking function can be generated between the transmission rod 3 and the slider 4.

As above, the invention made by the present inventor has been specifically explained based on Examples, but it should be noted that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Not even.

For example, the slide table using the ultrasonic linear motor of this embodiment is not limited to the structure and shape shown in FIG. 2, and the circuit for driving the ultrasonic linear motor is also similar to that shown in FIG. The circuit configuration is not limited to that shown.

[Effects of the Invention] Among the inventions disclosed in this application, the effects obtained by typical inventions are briefly described below.

(1) A first piezoelectric vibrator and a second piezoelectric vibrator excited by the application of a high-frequency voltage, a transmission rod fixed to these first and second piezoelectric vibrators, and a transmission rod attached to the transmission rod. When either the first or second piezoelectric vibrator is excited, a unidirectional traveling wave is formed on the transmission rod, and this traveling wave is
Alternatively, in an ultrasonic linear motor in which the traveling wave is absorbed by the other of the first piezoelectric vibrators, a thrust in the opposite direction to the traveling wave is generated on the slider, and the slider is driven in the opposite direction to the traveling wave by this thrust, An operation in which a high frequency power source is switchably connected to either the first or second piezoelectric vibrator, and a load resistor is connected or disconnected to the other of the second or I piezoelectric vibrator. By connecting the switch in series, the first or second piezoelectric vibrator is excited, and the load resistance of the second or first piezoelectric vibrator is connected, thereby generating a traveling wave on the transmission rod. Therefore, the slider that is brought into pressure contact with the transmission rod and the table that is operatively connected to the slider can be driven in a predetermined direction.

On the other hand, by opening the load resistance of the second or first piezoelectric vibrator, a standing wave is generated on the transmission rod, and the friction coefficient and wear between the transmission rod and the slider are reduced. Since the slider and table can be easily driven manually, it is possible to obtain an ultrasonic linear motor with a bearing function and a slide table using the same.

(2) When a high frequency power source is not connected to either the first piezoelectric vibrator or the second piezoelectric vibrator, the slider that is brought into pressure contact with the transmission rod can be brought into a self-locking state; An ultrasonic linear motor with a brake function and a slide table using the same can be obtained.

(3) According to (1) and (2) above, the slider and table can be driven in a predetermined direction or stopped at a predetermined position by connecting and disconnecting the high frequency power supply to the first and second piezoelectric vibrators. At the same time, it can be easily driven manually as well.
It is possible to obtain an ultrasonic linear motor that is suitable for adjustment and maintenance, and a slide table using the same.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a circuit of an ultrasonic linear motor which is an embodiment of the present invention. I is a plan view showing a slide table using the ultrasonic linear motor of this embodiment,
FIGS. 3(a) and 3(b) are explanatory diagrams showing the operation of the ultrasonic linear motor of this embodiment. DESCRIPTION OF SYMBOLS 1...First piezoelectric vibrator, 2...Second piezoelectric vibrator, 3...Transmission rod, 4...Slider, 5...Table, 6...Linear guide, 7... ... Main body, 8... Connection plate, 9... High frequency power supply, 10... Changeover switch, 11... Load resistance, 12... Operation switch. (a) (b)

Claims (3)

[Claims] 1. A first piezoelectric vibrator and a second piezoelectric vibrator excited by application of a high frequency voltage, a transmission rod fixed to the first and second piezoelectric vibrators, and a transmission rod brought into pressure contact with the transmission rod. a slider, a unidirectional traveling wave is formed on the transmission rod by exciting either the first or second piezoelectric vibrator, and the traveling wave is transmitted to the second or first piezoelectric vibrator. an ultrasonic linear motor in which the traveling wave generates a thrust in the opposite direction to the traveling wave on the slider, and the thrust drives the slider in the opposite direction to the traveling wave. A high frequency power source is switchably connected to either the first or second piezoelectric vibrator, and a load resistor is connected to the other of the second or first piezoelectric vibrator. Alternatively, operating switches to be opened are connected in series, and the first or second piezoelectric vibrator is excited and the load resistance of the second or first piezoelectric vibrator is connected. A traveling wave is generated on the transmission rod, and a standing wave is generated on the transmission rod by opening the load resistance of the second or first piezoelectric vibrator. An ultrasonic linear motor characterized in that the slider can be easily driven manually by reducing the coefficient of friction and wear between the slider and the slider. 2. Claim characterized in that when a high frequency power source is not connected to either the first piezoelectric vibrator or the second piezoelectric vibrator, the slider that is brought into pressure contact with the transmission rod is in a self-locking state. 1. The ultrasonic linear motor according to 1. 3. A slide table comprising a table using the ultrasonic linear motor according to claim 1 or 2 and operatively connected to the slider.