JP2005112517A - Object levitating and transporting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an object levitating and transporting device capable of transporting an object in the stably levitated condition by suppressing the deflection of vibrating plates despite their larger length. <P>SOLUTION: The object levitating and transporting device 11 is equipped with two vibrating plates 12a and 12b and is able to levitate the object 13 and hold with the two plates in cooperation. The vibrating plates 12a and 12b are supported by three horns 14a-14c, which are secured to a vibrator 15. The vibrator 15 to excite the horn 14c fastened to the center of the plates 12a and 12b is connected with an oscillator 19, while a vibrator 15 to excite the horns 14a and 14b fastened to the ends of the plates 12a and 12b is connected with the oscillator 19 through a phase shifter 21. The object levitating and transporting device 11 is structured so as to generate a standing wave from the plates 12a and 12b and is equipped with a nozzle 23 to give a propulsive force to the object 13 in the levitated condition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an object levitating and conveying apparatus that conveys an object in a levitated state using radiation pressure of sound waves.

  Glass substrates such as liquid crystal displays and PDPs (plasma displays) have become larger and have become larger than 1500 x 1800 mm, but there is a need for a device that floats objects to prevent substrate deflection and dust adhesion. It has been.

As an object levitating apparatus for levitating an object in the air, an apparatus using a sound wave radiation pressure has been proposed. An object levitating and conveying apparatus that uses a long flat plate-like vibrating body, levitates an object by the radiation pressure of sound waves generated by vibration of the vibrating body, and generates a traveling wave by the vibrating body to move the levitated object. It has been proposed (see, for example, Patent Document 1). If a long diaphragm is used to increase the object transport distance, the deflection will increase and the height will change near the end and center of the diaphragm, making it difficult to transport the object in a stable levitation state. become. In the object levitating and conveying apparatus disclosed in Patent Document 1, in order to eliminate this inconvenience, a deflection preventing member that abuts the lower surface of the diaphragm and suppresses the deflection of the diaphragm is provided in the middle portion of the diaphragm. .
Japanese Patent Laid-Open No. 2002-137817 (paragraphs [0015], [0018], [0021], FIG. 1)

  However, in the object levitating and conveying apparatus described in Patent Document 1, since the bending of the long diaphragm is suppressed by the deflection preventing member that contacts the lower surface of the diaphragm, the vibration of the diaphragm is increased. There is a problem that the diaphragm or the deflection preventing member is worn because the diaphragm repeatedly contacts the deflection preventing member. Further, if the contact is made at a position where vibration is small in order to suppress wear, the arrangement of the bending prevention member is limited.

  On the other hand, if the distance to transport the object is short, it can be transported by the object levitation transport device using a short diaphragm, but if the distance to transport the object is long, multiple object levitation transport devices are arranged in series. It is necessary to transport the object. However, when a plurality of object levitation conveyance devices are arranged in series to convey an object, the object in the levitation state is transferred from the vibration plate of one object levitation conveyance device to the vibration plate of the other object levitation conveyance device. In order to carry out smoothly, it is necessary to adjust the alignment of both the object levitation transfer devices with high accuracy. And as the number of the object levitation transfer devices to be used increases, the adjustment takes time. Further, since the number of components increases, the apparatus becomes expensive.

  The present invention has been made in view of the above-mentioned problems, and its object is to use a long diaphragm to support and excite the diaphragm at two places when an object is conveyed in a floating state. The object levitation conveying device is capable of conveying an object in a stable levitation state by suppressing the bending of the diaphragm even when the length of the diaphragm is increased.

  In order to achieve the above object, according to the first aspect of the present invention, an object levitating and conveying apparatus that excites a long diaphragm by an exciting means and conveys an object in a levitated state by the radiation pressure of sound waves from the diaphragm. The diaphragm is supported by three or more support portions, and at least one of the support portions is excited. Here, the “long diaphragm” means that the diaphragm has a length that is at least 10 wavelengths of the vibration wavelength.

  In this invention, since the vibration plate is supported by three or more support portions and vibrates, an object having the same weight is levitated as compared with the vibration plate of the conventional device that vibrates while being supported by the two support portions. The amount of bending at the time of making becomes small. Accordingly, the object is stably transported in the floating state. In addition, conventionally, it is possible to carry a single object levitating and conveying device even at a distance where two object levitating and conveying devices provided with short diaphragms are used. As a result, adjustment labor (man-hours) when installing the object levitation transfer device is reduced.

  According to a second aspect of the present invention, in the first aspect of the present invention, at least one of the support portions is a non-excited support portion, and the non-excited support portion is constituted by a horn. In the present invention, for example, one of the three or more support portions is excited, so that only one vibrator is required for excitation, and the cost is reduced. In addition, since the other non-excited support portion is a horn, it is easy to efficiently vibrate the diaphragm by the excitation means as compared with the case where the diaphragm is fixed to a support portion other than the horn.

  According to a third aspect of the invention, in the first aspect of the invention, the diaphragm is excited by a plurality of vibrators so as to generate traveling waves. As a method of transporting an object in a levitated state using a long diaphragm, a standing wave is generated by the diaphragm to hold the object in a levitated state, and the longitudinal direction of the diaphragm with respect to the object in that state There are a method of applying a propulsive force to move to a position and a method of generating a traveling wave with a diaphragm and transporting an object in a floating state by the traveling wave. In this invention, since the diaphragm is excited so as to generate a traveling wave, the configuration is simplified compared to a method in which a standing wave is generated and a driving force is separately applied. Further, since the diaphragm is excited by the plurality of vibrators, the excitation effect is enhanced.

  According to the present invention, when a long diaphragm is used to convey an object in a levitated state, the length of the diaphragm can be increased compared to a device that supports the diaphragm with two support portions. It can be transported in a stable levitation state.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic perspective view of an object levitating and conveying apparatus.

  As shown in FIG. 1, the object levitating and conveying apparatus 11 includes two diaphragms 12a and 12b excited by excitation means. Both diaphragms 12a and 12b are formed in the shape of a rectangular plate having the same size, and the object 13 to be transported can be floated and held together. The object 13 is a thin plate-like object such as a glass substrate of a liquid crystal panel. The diaphragms 12a and 12b are formed long. The long length means a length that is at least 10 times the wavelength when the diaphragms 12a and 12b vibrate. Desirably, when the length is equal to or larger than the glass substrate size (1500 mm or more), the connecting portions in the series direction are reduced, and stable conveyance is possible.

  Each diaphragm 12a, 12b is supported by horns 14a, 14b, 14c as three support portions. The horns 14a, 14b, and 14c are formed in a flat and substantially rectangular parallelepiped shape, and are fastened to the diaphragms 12a and 12b by screws (not shown) at their tips. The horns 14a and 14b are attached to the diaphragms 12a and 12b in a state perpendicular to the longitudinal direction at both ends in the longitudinal direction, and the horns 14c are longitudinal to the diaphragms 12a and 12b in substantially the center in the longitudinal direction. It is attached in a state perpendicular to the direction.

  Each horn 14a, 14b, 14c is fixed to the vibrator 15 on the surface opposite to the surface to which the diaphragms 12a, 12b are fastened. The tip surfaces of the horns 14a, 14b, 14c are formed on a plane orthogonal to the axial direction of the vibrator 15, and the horns 14a, 14b, 14c and the central axis of the vibrator 15 are arranged in a state extending in the vertical direction.

  A so-called Langevin-type vibrator is used as the vibrator 15 and includes a pair of ring-shaped piezoelectric elements 16a and 16b, a ring-shaped electrode plate 17 disposed between the piezoelectric elements 16a and 16b, and the piezoelectric elements 16a and 16b. The metal blocks 18a and 18b arranged at positions where they come into contact with the outer surface are fastened and fixed with bolts (not shown). The bolt is screwed into a screw hole (not shown) formed in the metal block 18a from the metal block 18b side. Both metal blocks 18a, 18b are in a state of being electrically connected to each other via bolts. A flange (not shown) is formed at the upper ends of the metal blocks 18a and 18b, and the metal block 18a is fixed to the support plate by a bolt (not shown) in a state of being fitted in a hole formed in the support plate (not shown). Yes. In other words, the object levitation transfer device 11 has a configuration in which two transfer units are arranged in parallel.

  A vibrator 15 for exciting a horn 14c fastened to the center of each diaphragm 12a, 12b is connected to an oscillator 19. The electrode plate 17 is connected to the oscillator 19 via the wiring 20a, and the ground terminal of the oscillator 19 is connected to the metal block 18b via the wiring 20b. The vibrator 15 for exciting the horns 14 a and 14 b fastened to the end portions of the diaphragms 12 a and 12 b is connected to the oscillator 19 via the phase shifter 21. The horns 14a to 14c, the vibrator 15, the oscillator 19, and the phase shifter 21 constitute excitation means for exciting the diaphragms 12a and 12b. The oscillator 19 and the phase shifter 21 are driven by a control signal from the control device 22. For the sake of illustration, the oscillator 19, the wirings 20a and 20b, and the phase shifter 21 for the diaphragm 12b are not shown.

  The phase difference between the vibrator 15 provided at both ends and the vibrator 15 provided in the center, which is suitable for vibrating the diaphragms 12a and 12b in the stripe mode, is previously tested according to the load and environmental temperature. The condition is stored in the memory of the control device 22.

  The object levitation transfer device 11 is configured to generate a standing wave from the diaphragms 12a and 12b, and includes a propulsive force applying unit that applies a propulsive force to the floating object. In this embodiment, a nozzle 23 that blows compressed air from behind on the object 13 is provided as a propulsive force applying means. A plurality of nozzles 23 are provided, but only one is shown.

Next, the operation of the apparatus configured as described above will be described.
The vibrator 15 is excited at a predetermined resonance frequency (for example, around 20 kHz), and the diaphragms 12a and 12b are excited via the horns 14a to 14c to perform flexural vibration. The diaphragms 12a and 12b are vibrated in a striped mode, and the object 13 is held in a state of being lifted from the surfaces of the diaphragms 12a and 12b by the radiation pressure of sound waves emitted from the diaphragms 12a and 12b. In this state, compressed air is jetted from the nozzle 23 to apply a thrust to the object 13, and the object 13 is conveyed in a floating state from one end side to the other end side of the diaphragms 12a and 12b. By stopping the jet of compressed air from the nozzle 23, the conveyance of the object 13 is stopped, and the object 13 is held in a fixed position in a floating state. When the drive of the oscillator 19 is stopped, the vibrations of the diaphragms 12a and 12b are stopped, and the object 13 is stopped while being placed on the diaphragms 12a and 12b.

  In order to increase the transport distance of the object 13 with one object levitation transport device 11, it is necessary to lengthen (long) each diaphragm 12a, 12b. However, in the configuration in which the vibration plates 12a and 12b are supported and vibrated at two locations as in the conventional device, the vibration plate is greatly bent without the bending prevention device, and it is difficult to convey the object 13 in a stable state. However, in this embodiment, in addition to the both ends of each diaphragm 12a, 12b being supported by horns 14a, 14b, the substantially central part of each diaphragm 12a, 12b is also supported by horn 14c. Therefore, the bending of each diaphragm 12a, 12b is suppressed, and the object 13 is conveyed in a stable floating state from one end to the other end of the diaphragm 12a, 12b in a substantially horizontal state.

This embodiment has the following effects.
(1) In the object levitating and conveying apparatus 11 that conveys the object 13 in a levitated state by the radiation pressure of sound waves from the long vibrating plates 12a and 12b, the vibrating plates 12a and 12b have three support portions (horns 14a to 14c). It is supported by and vibrates. Accordingly, the amount of bending when the object 13 having the same weight is levitated is smaller than that of the diaphragm of the conventional apparatus that vibrates while being supported by the two support parts, and the object 13 is stably in the levitated state. Can be transported. In addition, conventionally, even when the object levitation conveyance device having a short diaphragm is used for conveyance, it can be conveyed by one object levitation conveyance device 11 by lengthening the diaphragms 12a and 12b. It becomes possible. When the object 13 is transferred using two object levitation transfer devices, the object 13 can be smoothly transferred from one object levitation transfer device to the other object levitation transfer device when the object levitation transfer device is installed. In addition, it is necessary to accurately adjust the height of the surfaces of the diaphragms 12a and 12b (alignment adjustment), which takes time and effort. However, when the object levitation transfer device 11 is used to transfer the object, the alignment adjustment effort (man-hour) is reduced when the object levitation transfer device 11 is installed. Further, even when a plurality of object levitation transfer devices 11 are required and the object 13 is transferred, the number of the object levitation transfer devices 11 can be reduced as compared with the conventional device, and the number of man-hours for installation can be reduced.

  (2) The diaphragms 12 a and 12 b are excited by a plurality of vibrators 15. In the case of a long diaphragm, the vibration attenuation is larger than that of a conventional short diaphragm, but the excitation effect is enhanced by excitation by a plurality of vibrators.

  (3) Each of the diaphragms 12a and 12b is excited by a plurality of vibrators 15, and part of the vibrators 15 are vibrated with the phase adjusted by the phase shifter 21, so that the diaphragms 12a and 12b are striped. It becomes easy to vibrate in the mode, and the 12a and 12b can be vibrated efficiently and in a state where a uniform radiation pressure is generated.

  (4) The diaphragms 12a and 12b generate standing waves to hold the object 13 in a floating state, and the longitudinal direction of the diaphragms 12a and 12b is caused by the compressed air injected from the nozzle 23 to the object 13 in that state. The object 13 is conveyed in a levitating state by applying a propulsive force to move the object to Therefore, the configuration of the excitation means is simpler than the configuration in which traveling waves are generated in the diaphragms 12a and 12b and the object 13 is conveyed in a floating state.

  (5) Since a plurality of (two in this embodiment) diaphragms 12a and 12b are provided in parallel and these diaphragms 12a and 12b jointly hold the object 13 in a levitated state, the width is wide (for example, the width is The object 13 can be transported in a stable levitation state.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. This embodiment is greatly different from the first embodiment in that the diaphragms 12a and 12b are excited so as to generate traveling waves, and no applying means for applying a propulsive force to the object 13 is provided. As in the first embodiment, the two diaphragms 12a and 12b are arranged in parallel, and the diaphragms 12a and 12b are excited by the excitation means having the same configuration. Only the diaphragm 12a is illustrated. Also, the same parts as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The vibrator 15 fastened to the horns 14a and 14c is connected to the oscillator 19 and the phase shifter 21, respectively, as in the first embodiment. The vibrator 15 fastened to the horn 14b is not connected to the oscillator 19 or the phase shifter 21, but is connected to a load circuit 24 as an energy conversion means including a resistor R and a coil L.

Next, the operation of the apparatus configured as described above will be described.
The vibrator 15 to which the horns 14a and 14c are fastened is excited at a predetermined resonance frequency (for example, around 20 kHz), and the diaphragms 12a and 12b are excited through the horns 14a and 14c to cause flexural vibration. The object 13 is levitated from the surfaces of the diaphragms 12a and 12b by the radiation pressure of the sound waves radiated from the diaphragms 12a and 12b.

  The vibrations of the diaphragms 12a and 12b are transmitted from the horn 14b to the vibrator 15 connected to the load circuit 24. The piezoelectric elements 16a and 16b constituting the vibrator 15 convert vibration energy, which is mechanical energy, into electric energy. The This electrical energy is converted into Joule heat by the resistance R of the load circuit 24 and is dissipated. Therefore, the vibration wave generated in each diaphragm 12a, 12b becomes a traveling wave traveling in one direction (in this embodiment, traveling wave traveling from the horn 14a side to the horn 14b side), and the object 13 is one end of the diaphragms 12a, 12b. It is conveyed in a floating state from one side to the other end side. The conveyance is stopped by stopping the driving of the oscillator 19.

In addition to the same effects as (1) to (3) and (5) of the first embodiment, this embodiment has the following effects.
(6) Since the traveling wave is generated from the diaphragms 12a and 12b, it is not necessary to separately provide a propulsion force applying means for transporting the object 13 in a floating state, and the configuration is simplified.

The embodiment is not limited to the above, and may be configured as follows, for example.
As shown in FIG. 3, as a configuration for generating standing waves on the diaphragms 12a and 12b, the vibrator 15 is fastened only to the central horn 14c, and the other horns 14a and 14b support the diaphragms 12a and 12b. It is good also as a structure which functions only as a part. In this configuration, it is preferable that the resonance frequencies of the horns 14a and 14b are formed in accordance with the resonance frequencies of the diaphragms 12a and 12b. Also in this case, the long diaphragms 12a and 12b are vibrated uniformly without problems of bending due to their own weight, and uniform radiation pressure can be generated from the diaphragms 12a and 12b. Moreover, since the support part which is not excited is a horn, compared with the case where a diaphragm is fixed to support parts other than a horn, it is easy to vibrate a diaphragm efficiently by an excitation means. In addition, it is not necessary to dispose the support portion that is not excited at a position where vibration is small, and the flexibility is high.

○ The support is not limited to a horn. What is necessary is just to be able to support without disturbing vibration transmission.
In the object levitating and conveying apparatus 11 that conveys the object 13 in a levitated state using traveling waves, the vibrators 15 provided at both ends of the diaphragms 12a and 12b are selectively used as the oscillator 19 and the load circuit 24, respectively. Configure to be switchable. In this case, the conveyance direction of the object 13 can be selected by switching between the state connected to the oscillator 19 and the state connected to the load circuit 24.

  The number of diaphragms 12a and 12b is not limited to two, and when a wide object 13 is levitated and conveyed, diaphragms may be further arranged in parallel between the diaphragms 12a and 12b. The diaphragm disposed between them is not necessarily configured to generate a traveling wave, and may be configured to generate a standing wave. In this case, the bending of the object 13 itself due to the weight of the object 13 is suppressed, and the object 13 can be smoothly conveyed in a floating state.

  O Instead of a configuration in which the object 13 is levitated and held by the plurality of diaphragms 12a and 12b, a configuration in which the object 13 is levitated and held by one diaphragm may be employed. For example, when the object 13 having a narrow width is levitated and conveyed, even if only one diaphragm is used, it can be stably conveyed.

○ When the transport distance is long, the object levitation transport device 11 may be configured by arranging a plurality of object levitation transport devices 11 in series.
The number of support parts that support the diaphragms 12a and 12b is not limited to three, and may be four or more.

A plurality of vibrators 15 may share the oscillator 19.
The shape of the horns 14a and 14b is not limited to a flat rectangular parallelepiped shape, and may be a shape with a thin tip such as a columnar shape or a substantially truncated cone shape.

The shape of the object 13 to be levitated and held is not limited to a quadrangle, and may be an arbitrary shape such as a triangle, another polygon, or a circle.
The fixing of the diaphragms 12a and 12b to the horns 14a and 14b is not limited to fastening with screws, and an adhesive may be used, or may be fixed by brazing or welding.

The vibrator 15 is not limited to the Langevin type vibrator, and other vibrators may be used.
The following technical idea (invention) can be understood from the embodiment.
(1) In the invention according to claim 1 or 3, the diaphragm is vibrated in a stripe mode.

  (2) In the invention according to any one of claims 1, 2 and technical idea (1), the object levitation transfer device is configured to generate a standing wave from the diaphragm, and is in a levitation state. Propulsive force applying means for applying a propulsive force to the object is provided.

  (3) In the invention according to any one of claims 1 to 3 and technical ideas (1) and (2), a plurality of the diaphragms are provided in parallel.

The model perspective view of the object levitation conveyance apparatus of 1st Embodiment. The partial model perspective view of the object levitation conveyance apparatus of 2nd Embodiment. The partial model perspective view of the object levitation conveyance apparatus of another embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Object levitating conveyance apparatus, 12a, 12b ... Diaphragm, 13 ... Object, 14a, 14b, 14c ... Constitution which comprises an excitation means and a horn as a support part, 15 ... Vibrator which comprises excitation means, 19 ... Similarly oscillator .. 21 Phase shifter.

Claims (3)

An object levitating and conveying device that excites a long diaphragm with an exciting means and conveys an object in a levitating state by radiation pressure of sound waves from the diaphragm,
The vibrating plate is supported by three or more support portions, and at least one of the support portions is excited.   The object levitation conveyance apparatus according to claim 1, wherein at least one of the support parts is a support part that is not excited, and the support part that is not excited is configured by a horn.   The object levitation conveyance apparatus according to claim 1, wherein the diaphragm is excited to generate traveling waves by a plurality of vibrators.

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