JP4891562B2 - Drive device and drive / guide device - Google Patents

Description

The present invention relates to, for example, a drive device and a drive / guide device used in a precision positioning system, and more particularly to a device devised so as to simplify the configuration and improve wear resistance.

  Examples of the positioning device using ultrasonic driving include those described in Patent Document 1 and Patent Document 2.

JP 2004-298773 A JP 2003-339175 A

The conventional configuration has the following problems.
First, there is a problem that the configuration is complicated in both cases of the apparatus described in Patent Document 1 and the apparatus described in Patent Document 2. That is, there is a problem that the ultrasonic vibration generator and the two guide rails are used for driving and guiding the stage, so that the number of parts is large and the structure becomes complicated. In addition, there is a problem that a large installation space is required, and the downsizing of the apparatus is hindered, and more man-hours are required for assembling due to the number of parts, and the assembling accuracy is lowered. .
In addition, there was a problem of wear resistance. That is, since there is a speed difference between the speed of the fixed side that vibrates ultrasonically and the speed of the movable part, “slip” occurs between the two, and the “slip” causes wear. Therefore, in the case of the apparatus described in Patent Document 1, the driving force transmission member is made special or coated with a special lubricating film in order to improve wear resistance. In the case of the apparatus described in Patent Document 2, a special measurement / monitoring unit is provided in order to accurately measure the degree of wear.

The present invention has been made based on these points, and an object of the present invention is to provide a drive device and a drive / guide device that have a simple structure and are easy to assemble and have excellent wear resistance. .

In order to achieve the above object, a driving apparatus according to claim 1 of the present invention includes a fixed portion, a movable portion that is movably installed in contact with the fixed portion, and a fixed portion or a movable portion. A plurality of ultrasonic vibration generators that generate elliptical motion on the surface of the fixed part or the movable part by generating ultrasonic vibrations, and a phase difference controller that controls the phase difference between the plurality of ultrasonic vibration generators. The tangential velocity (Fx) in the elliptical motion is controlled without reducing the pressing force (Fy) in the elliptical motion by controlling the phase difference by the phase difference controller, and the tangential line with speed and (Fx) a positioning controller for instructing proper the phase difference to suppress the speed difference between the speed of the movable part, further operation of the positioning controller Anda controller having an amplitude controller for controlling the amplitude of the ultrasonic vibration generator according to a command, the control device, in order to suppress the slip, by the positioning controller, the tangential speed (Fx) The phase difference and tangential speed (Fx) are set to a small phase difference and tangential speed (Fx) immediately after the start of driving so that the speed of the movable part does not greatly deviate from the above, and the phase difference and tangential speed (Fx) are gradually increased to increase the speed. it is characterized in that the stop is to control to slow down gradually to small phase difference and a tangential velocity (Fx).
According to a second aspect of the present invention, there is provided a drive / guide device according to the first aspect, wherein the drive device according to the first aspect, the drive device according to the first aspect, and the ultrasonic vibration generator provided in the fixed part or the movable part are ultrasonically vibrated. And a guide surface for guiding the movement of the movable part.
According to a third aspect of the present invention, in the driving / guidance device according to the second aspect, the guide surface is an inclined surface.
The drive / guide device according to claim 4 is the drive / guide device according to claim 3, characterized in that the guide surface is a pair of C-shaped or inverted C-shaped slopes. .
According to a fifth aspect of the present invention, there is provided the driving device according to the first aspect, wherein the movable portion is pressed against the fixed portion by magnetic attraction.
According to a sixth aspect of the present invention, there is provided the driving / guide device according to the second aspect, wherein the movable portion is pressed against the fixed portion by magnetic attraction.

As described above, according to the driving device of the present invention, the fixed portion, the movable portion that is movably installed in contact with the fixed portion, and the ultrasonic vibration generated in the fixed portion or the movable portion is generated. A plurality of ultrasonic vibration generators and a control device that controls the phase difference between the plurality of ultrasonic vibration generators, so that the pressing state of the movable part against the fixed part is not impaired. It becomes possible to eliminate the sliding of the movable part, and to greatly improve the wear resistance.
In addition, the control device is controlled so that the phase difference is small immediately after the start of driving, the phase difference is gradually increased to increase the speed, and the speed is gradually decreased to a small phase difference at the time of stop. When configured, it is possible to effectively improve the wear resistance by effectively eliminating slipping from start to stop.
According to the guide device of the third aspect, the fixed portion, the movable portion installed so as to be movable while being in contact with the fixed portion, and a plurality of ultrasonic vibrations provided on the fixed portion or the movable portion. And a guide surface that is provided on the fixed part or the movable part and is ultrasonically vibrated by the ultrasonic vibration generator and guides the movement of the movable part. In addition, it is not necessary to install a separate guide rail, and the configuration can be simplified and the number of assembly steps can be reduced.
Further, when the guide surface is an inclined surface, a desired effect can be obtained with a relatively simple configuration.
In addition, when the guide surface is a pair of C-shaped or inverted C-shaped slopes, a desired effect can be obtained with a relatively simple configuration.
According to the drive / guide device of claim 6, the fixed portion, the movable portion installed so as to be movable while being in contact with the fixed portion, and the ultrasonic vibration generated in the fixed portion or the movable portion are generated. A plurality of ultrasonic vibration generators, a control device for controlling a phase difference between the plurality of ultrasonic vibration generators, and the ultrasonic vibration generator provided in the fixed part or the movable part and ultrasonically vibrated as described above. Since the guide surface for guiding the movement of the movable part is provided, it is possible to eliminate the sliding of the movable part without impairing the pressing state of the movable part against the fixed part, and to improve the wear resistance. In addition to being able to greatly improve, there is no need to install a separate guide rail, and the configuration can be simplified and the number of assembly steps can be reduced.
In addition, when the movable part is pressed against the fixed part by magnetic attraction, the movable part is more firmly attached to the fixed part without increasing the weight of the movable part.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a configuration of a drive / guide device according to the present embodiment, where FIG. 1 (a) is a plan view of the drive / guide device, FIG. 1 (b) is a side view of the drive / guide device, and FIG. (c) is cc sectional drawing of Fig.1 (a). First, there is a fixing portion 1, and the fixing portion 1 includes a fixed-side guide portion 3 having a square shape. The fixed-side guide portion 3 includes a pair of short sides 5 and 7 and a pair of long sides 9 and 11.

  Ultrasonic vibration generators 13 and 15 are respectively installed at the positions of the short sides 5 and 7 at the left and right end portions of the fixed-side guide portion 3. The ultrasonic vibration generator 13 is composed of support members 17 and 19 that are flat and bent in an L shape, and a Langevin ultrasonic transducer 21. The ultrasonic vibration generator 13 is installed on the base 23 via the support members 17 and 19. The Langevin type ultrasonic transducer 21 has piezoelectric materials 21a and 21a arranged on both sides of the short side 5 and resonance vibration weights 21b and 21b arranged outside the piezoelectric materials 21a and 21a. The short side 5 is screwed with a screw member (not shown) via the support members 17 and 19. That is, the short side 5 is used as a component of the Langevin type ultrasonic transducer 21. By comprising in this way, the ratio of the space which occupies the inner side of the short side 5 will be halved.

The support members 17 and 19 are L-shaped plate members, which have a large rigidity in the vertical direction (Z direction) for supporting the guide weight, but have a rigidity in the vibration direction of the Langevin type ultrasonic vibrator 13. The structure is low and easy to bend. Therefore, the vibration suppression by the support other than the vibration node can suppress the vibration attenuation by the present structure which has a low rigidity in the vibration direction (Y direction) and is easily bent.

  The ultrasonic vibration generator 15 has the same configuration. That is, the ultrasonic vibration generator 15 is composed of support members 25 and 27 that are flat and bent in an L shape, and a Langevin type ultrasonic transducer 29. The ultrasonic vibration generator 15 is installed on the base 23 through the support members 25 and 27. In the Langevin type ultrasonic transducer 29, piezoelectric materials 29a and 29a are arranged on both sides of the short side 7, and resonant vibration weights 29b and 29b are arranged outside the piezoelectric materials 29a and 29a. The short side 7 is screwed with a screw member (not shown) through the support members 25 and 27. That is, the short side 7 is used as a component of the Langevin type ultrasonic transducer 29. By comprising in this way, the ratio of the space which occupies the inner side of the short side 7 will be halved.

The support members 25 and 27 are plate members bent in an L shape, and the rigidity is large in the vertical direction (Z direction) supporting the weight of the guide, but the rigidity in the vibration direction of the Langevin type ultrasonic transducer 13 is not. The structure is low and easy to bend. Therefore, the vibration suppression by the support other than the vibration node can suppress the vibration attenuation by the present structure which has a low rigidity in the vibration direction (Y direction) and is easily bent.

  A movable part 31 is installed on the fixed part 1. The movable portion 31 is configured to be movable in contact with the fixed portion 1. That is, inclined surfaces 9a, 9b, 11a, and 11b are formed on the pair of long sides 9 and 11 of the fixed portion 1, and are symmetrical in the vertical direction as shown in FIG. It has a shape. In addition, inclined surfaces 31a and 31b are formed on the movable portion 31 side so as to face this. The inclined surfaces 9a, 11a, 31a, and 31b function as guide surfaces with each other, and the movable portion 31 moves in the Y direction while being in contact with each other.

  Further, a magnetic attraction yoke 41 is installed on the base 23, and a magnet 43 and a back yoke 45 are installed on the movable portion 31 above the magnetic attraction yoke 41. The principle of the drive device according to the present embodiment is friction drive. If the movable portion 31 is not pressed against the fixed-side guide portion 3, a sufficient friction force cannot be obtained and cannot be slid and driven. At that time, the pressing by gravity due to the increase in the weight of the movable portion 31 is also effective, but the weight of the movable portion 31 increases, which is disadvantageous for increasing the acceleration. Therefore, in the case of the present embodiment, the pressing force is obtained by the magnetic attraction force between the magnet 43 and the iron magnetic attraction yoke 41 fixed to the fixed base portion 23. In this case, it can be configured with few components and not much space.

Next, the configuration of the control device will be described with reference to FIG. As shown in FIG. 2, first, a phase difference controller 51 that provides a phase difference between the ultrasonic vibration generators 13 and 15 is provided. A linear encoder 53 is installed, and position information from the linear encoder 53 is output to the positioning controller 55. The positioning controller 55 calculates an appropriate tangential velocity based on the input position information, and instructs the phase difference controller 51 of an appropriate phase difference. An appropriate phase difference is applied between the ultrasonic vibration generators 13 and 15 via the drivers 57 and 59 of the ultrasonic vibration generators 13 and 15.
In FIG. 2, reference numeral 61 denotes an amplitude controller. The amplitude controller 61 controls the amplitude by calculation / command of the positioning controller 55, and can control not only the phase difference control but also the amplitude as required.

The operation will be described based on the above configuration. First, the driving principle by ultrasonic vibration will be described with reference to FIG. A traveling wave is generated on the fixed portion 1 side by the ultrasonic vibration generated by the ultrasonic vibration generators 13 and 15 described above. Then, an elliptical motion as shown in the figure is generated on the surface of the fixed guide portion 3 of the fixed portion 1. On the other hand, the movable part 31 is pressed onto the fixed side guide part 3 by its own weight and magnetic attraction. As a result, thrust is applied to the movable portion 31.
Incidentally, in the case shown in FIG. 3A, the counterclockwise elliptical motion is generated, and thus a thrust force that moves the movable portion 31 leftward in FIG. 3A is generated.

Now, in order to reduce wear, it is necessary to eliminate “slip” between the fixed side guide portion 3 and the movable portion 31 as much as possible. That is, if there is a speed difference between the tangential speed to the contact point (contact point on the inclined surfaces 9a and 11a) of the fixed side guide part 3 provided by the elliptical motion and the speed of the movable part 31, it is caused. Thus, the above “slip” occurs. Therefore, the speed difference must be suppressed as much as possible. In particular, since a speed difference is likely to occur between “starting” and “stopping”, it is necessary to effectively reduce it.

First, in the case of startup, the operating unit 31 is stopped, so the speed is “0”. Therefore, in order to suppress the slip, it is necessary to suppress the tangential velocity due to the elliptical motion of the fixed side guide portion 3 in the vicinity of “0”.

As a method of suppressing the tangential velocity due to the elliptical motion of the fixed side guide portion 3 to near “0”, it is conceivable to lower the supply voltage to the ultrasonic vibration generators 13 and 15. That is, as shown in FIG. 3B, the tangential velocity under pressure in the elliptical motion is proportional to the lateral radius of the ellipse. Therefore, if the tangential velocity (Fx) is lowered by lowering the supply voltage to the ultrasonic vibration devices 13 and 15, the tangential velocity due to the elliptical motion of the fixed guide portion 3 can be suppressed to the vicinity of “0”.

However, in this method, as shown in FIG. 3B, the pressing force (Fy) also decreases. The frictional force also decreases due to a decrease in the pressing force (Fy), and as a result, there arises a problem that it becomes slippery. Another problem is that if the supply voltage is lowered too much, normal ultrasonic resonance is impaired.

Therefore, in the present embodiment, the tangential velocity (Fx) is controlled by reducing the phase difference between the ultrasonic vibration generators 13 and 15 without reducing the pressing force (Fy). is there. That is, for example, when the phase difference between the two ultrasonic vibration generators 13 and 15 is (φ), the elliptical motion shape at that time is expressed by the following equations (I) and (II).
y = asinθ ――― (I)
x = bsin (θ−φ) —— (II)
However,
a: Maximum amplitude of the ultrasonic vibration generator 13 b: Maximum amplitude of the ultrasonic vibration generator 15 θ: Phase

That is, as shown in FIG. 3C, as the phase difference (φ) is decreased, the tangential velocity (Fx) is reduced, but the pressing force (Fy) is increased. Even if the phase difference (φ) is “0”, the tangential velocity (Fx) is “0”, but the pressing force (Fy) vibrates sufficiently (in this case, not elliptical motion, The traveling wave stops and becomes a stationary wave). Thus, by controlling the phase difference (φ), the tangential velocity (Fx) and the thrust can be easily controlled from “0” without reducing the pressing force (Fy). This also applies to “when stopped”.
Further, when the movable portion 31 moves at a high speed, if the phase difference (φ) is set close to “90 °”, the tangential speed (Fx) is sufficiently increased to enable high-speed driving.

FIG. 4 shows a series of phase difference (φ) control from “starting” to “stopping”. In order to suppress wear problems due to “slip”, the phase difference (φ) is controlled to be close to “0” at the time of “start-up”, and then the phase difference (φ) is gradually increased. As a result, the movable part 31 is driven without slipping, and the speed is gradually increased to reach the target speed. On the contrary, at the time of “stop”, the phase difference (φ) is gradually brought close to “0” to suppress “slip”.

Further, as described in the description of the conventional example, the ultrasonic driving device in the conventional example is provided with two guide rails as a guide. Therefore, not only the number of parts is large but also assembly is required, and there is a problem that an expensive assembly cost is required particularly for a high precision required product. On the other hand, in the case of the present embodiment, since the ultrasonic vibration surface is used as the guide surface, the guide rail can be dispensed with.

More specifically, in the case of the present embodiment, as shown in FIG. 1C, the fixed-side guide portion 3 is provided with “C” -shaped inclined guide surfaces 9a and 11a. On the other hand, "C-shaped" guide surfaces 31a and 31b are also provided on the movable portion 31 side. By these inclined guide surfaces 9a and 11a and the inclined guide surfaces 31a and 31b, the movable portion 31 is a linear guide regulated in the left-right direction. That is, a desired guide can be provided without requiring a conventional guide rail.

As described above, according to the present embodiment, the following effects can be obtained.
First, wear resistance can be improved. By controlling the phase difference (φ) of the ultrasonic vibration generators 13 and 15, the tangential velocity (Fx) and thrust can be easily controlled from “0” without reducing the pressing force (Fy). This is because it was possible to eliminate the “slip” that causes wear.
Further, the configuration can be simplified and the number of parts can be reduced. This is because the "G" -shaped inclined guide surfaces 9a and 11a are provided on the fixed-side guide portion 3, while the "C" -shaped guide surfaces 31a and 31b are also provided on the movable portion 31 side. This is because the guide surfaces 9a and 11a and the inclined guide surfaces 31a and 31b are configured to linearly guide the movable portion 31 in a state in which the movable portion 31 is restricted in the left-right direction. It is because it can provide.
This also reduces the number of assembly steps and increases the assembly accuracy.

The present invention is not limited to the one embodiment.
First, in the above-described embodiment, a configuration including two ultrasonic vibration generators has been described as an example. However, three or more cases may be considered, and the number is not limited.
In addition, the structure of each part is an example to the last.

The present invention relates to, for example, a drive device and a drive / guide device used in a precision positioning system, and particularly relates to a device devised so as to simplify the configuration and improve wear resistance. Is preferred.

1A and 1B are diagrams showing an embodiment of the present invention, in which FIG. 1A is a plan view showing the configuration of a drive / guide device, FIG. 1B is a side view of the drive / guide device, and FIG. It is cc sectional drawing of 1 (a). It is a figure which shows one embodiment of this invention, and is a block diagram which shows the structure of a phase difference control apparatus. FIGS. 3A and 3B are diagrams illustrating an embodiment of the present invention, FIG. 3A is a diagram for explaining a driving principle, FIG. 3B is a diagram illustrating elliptical motion according to a comparative example, and FIG. It is a figure which shows the elliptical motion by a form. It is a figure which shows one embodiment of this invention, and is a characteristic view which shows the time change of a phase difference.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed part 3 Fixed part guide 5 Short side of fixed part guide 7 Short side of fixed part guide 9 Long side of fixed part guide 9a Inclined surface 9b Inclined surface 11a Inclined surface 11b Inclined surface 11 Long side of fixed part guide 13 Vibration generation Device 15 Vibration generator 17 Support member 19 Support member 21 Langevin type vibrator 23 Base 25 Support member 27 Support member 29 Langevin type vibrator 31 Movable part 31a Inclined surface 31b Inclined surface 41 Magnetic attraction yoke 43 Magnet 45 Back yoke 51 Phase difference Controller 53 Linear encoder 55 Positioning controller 57 Driver 59 Driver 61 Amplitude controller

Claims (6)

A fixed part;
A movable part installed so as to be movable while in contact with the fixed part;
A plurality of ultrasonic vibration generators that are provided in the fixed part or the movable part to generate an elliptical motion on the surface of the fixed part or the movable part by generating ultrasonic vibration;
A phase difference controller that controls the phase difference of the plurality of ultrasonic vibration generators is provided, and the pressing force (Fy) in the elliptical motion is reduced by controlling the phase difference by the phase difference controller. A positioning controller that controls the tangential velocity (Fx) in the elliptical motion without any problem and that indicates the appropriate phase difference that suppresses the velocity difference between the tangential velocity (Fx) and the velocity of the movable part. And a control device including an amplitude controller that controls the amplitude of the ultrasonic vibration generator according to the calculation / command of the positioning controller ,
In order to suppress slipping, the control device has a small phase difference and a tangential speed (Fx) immediately after the start of driving so that the tangential speed (Fx) and the speed of the movable part are not greatly deviated by the positioning controller. ), and gradually working to significantly speed up the phase difference and a tangential velocity (Fx), also, it controls to slow down to stop gradually small phase difference and a tangential velocity (Fx) A drive device characterized by that. A drive device according to claim 1;
A drive / guide device comprising: a guide surface provided on the fixed portion or the movable portion and ultrasonically vibrated by the ultrasonic vibration generator and guiding the movement of the movable portion. The drive / guide device according to claim 2,
The drive / guide device, wherein the guide surface is a slope. The drive / guide device according to claim 3,
The drive / guide device, wherein the guide surface is a pair of C-shaped or inverted-C-shaped slopes. The drive device according to claim 1, wherein
A driving apparatus characterized in that the movable part is pressed against the fixed part by magnetic attraction. The drive / guide device according to claim 2,
A drive / guide device characterized in that the movable part is pressed against the fixed part by magnetic attraction.

Images