JP2005319563A - Oscillating table - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin oscillating table capable of imparting almost uniform oscillation to the entire oscillating table in the oscillating table for fixing and holding a workpiece to a machining device. <P>SOLUTION: The oscillating table 1 is composed of a stainless-steel block 2 and a laminated piezoelectric element 3. A bolt hole 4 for mounting the stainless-steel block 2 to a machining device is provided at four parts in the stainless-steel block 2. The block 2 is manufactured by electric discharge machining. The block 2 is provided with a space part 7 at its central part in order to reduce the mass of the oscillating block, a thin-wall part 8 for enlarging a displacement amount by forced oscillation, a fixing part 6 for fixing the laminated piezoelectric element 3, and a movable fixing-part 5 for receiving the displacement of the laminated piezoelectric element 3. An epoxy resin is used for fixing the laminated piezoelectric element 3 to the movable fixing-part 5 and the fixing part 6. A voltage, which changes with the elapse of time, is impressed to the laminated piezoelectric element 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vibration table used for cutting, grinding and polishing of semiconductors such as glass, ceramic, silicone, titanium, and super hard metal.

  Generally, it is very difficult to cut and grind brittle materials with high hardness such as glass, ceramic, silicone, titanium, and super hard metal. Has been done. In such ultrasonic cutting, the cutting resistance is reduced, so that the frictional heat of the cutting tool is reduced, the thermal distortion of the processed surface is reduced, the life of the cutting tool is extended, and the processing accuracy is improved. Ultrasonic cutting is described in detail in “Ultrasonic Handbook” (Maruzen Co., Ltd., published in 1999), pages 679-684.

  In addition, it is well known in the art to apply ultrasonic vibration to a work table for fixing a work, propagate the work to the work, and perform ultrasonic cutting. For example, in Japanese Patent Laid-Open No. 2002-355726, as shown in FIG. 8, an ultrasonic vibration table is a table device capable of fixing a workpiece to be processed by being attached to a bed of a machine tool, and shielded on an aluminum casing. An ultrasonic vibration device that is fixed via a rubber plate for vibration and that vibrates up and down, a vibration plate that fixes the lower middle portion to the upper end portion of the ultrasonic vibration device, and a lower portion of the vibration plate And a guide member which is inserted into a guide recess formed outside the ultrasonic vibration device of the casing and guides in the vertical direction while restricting the lateral movement of the diaphragm. The casing is formed in a box shape that opens upward, and a ring-shaped inner flange portion that protrudes inward is formed on the inner periphery. Female thread portions that penetrate vertically are formed at a plurality of locations on the inner flange portion. The iron back plate provided in the casing is detachably formed by a bolt member.

However, in ultrasonic cutting, when the tool is enlarged, it is very difficult to give uniform ultrasonic vibration to the processed portion of the tool that comes into contact with the workpiece.
In addition, when the tool is downsized, the device for applying ultrasonic vibration must be downsized. The smaller the ultrasonic vibration device is, the smaller the vibration energy given to the tool. For this reason, when a tool is small, there exists a fault that an ultrasonic cutting capability will become small.

On the other hand, the ultrasonic vibration table can be vibrated regardless of the shape of the tool. However, since the area of the ultrasonic radiation surface of the ultrasonic transducer is smaller than the area of the table, there is a drawback that uniform vibration displacement cannot be obtained in the entire table.
Moreover, it is normal that the processing apparatus generally has no space for accommodating a high vibration table, and there is a problem that a high vibration table cannot be installed in the processing apparatus.
Furthermore, the ultrasonic vibration table has an ultrasonic transducer fixed to the table surface, so if the table mass is large, the table surface tends to become a node of vibration, and the ultrasonic vibration of the table surface may be reduced. There is also a problem that is high.
In addition, since the ultrasonic vibration table must be driven at the resonance frequency including the workpiece, there is a problem in that it cannot be driven at that frequency even if there is an optimum frequency in the processing conditions.
Furthermore, the driving frequency of the ultrasonic vibration table is 15 KHz or higher, and vibrational displacement is small at frequencies below that, and there is a problem that frequencies below 15 KHz are hardly available.
An object of the present invention is to provide a vibration table that solves the above-mentioned problems.

  The present invention is characterized in that, in a table apparatus for fixing and holding a workpiece to be processed, which is attached to a processing apparatus, a laminated piezoelectric element is attached to the table and the table apparatus is vibrated by applying a voltage to the laminated piezoelectric element. This is a vibration table device.

  The present invention provides a vibration table device in which a voltage applied to the multilayer piezoelectric element changes 100 times or more and 15000 times or less per second.

  The present invention provides a vibration table device in which the displacement direction of the laminated piezoelectric element is perpendicular to the table surface.

  The present invention provides a vibration table device in which the displacement direction of the laminated piezoelectric element is parallel to the table surface.

  The present invention combines all or two of a vibration table device that vibrates in a direction perpendicular to the table surface, a vibration table device that vibrates in a direction parallel to the table surface, and a vibration table device that vibrates angularly with respect to the central axis on the table surface. The vibration table device to be used is used.

Since the vibration table of the present invention can excite a substantially uniform vibration on the surface of the vibration table, a substantially uniform vibration propagates to the work held and fixed on this surface regardless of the location. As a result, it is possible to improve the processing speed of the workpiece held and fixed and process difficult-to-work materials without being substantially affected by the position and size of the workpiece held and fixed on the vibration table.
Moreover, since the vibration table of the present invention can be thin, it can be installed in almost all processing apparatuses.
Furthermore, since the vibration table of the present invention vibrates in a non-resonant state, the frequency can be selected depending on the workpiece.

  The present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing an example of a vibration table having a first configuration according to the present invention.

  Almost the same configuration is used as a positioning stage used in a microscope. Details of this content are described in pages 490 to 500 of "New Actuator Handbook for Precision Control, 1994, Fuji Techno System Co., Ltd.". The laminated piezoelectric element used for the positioning stage is used as a displacement element. On the other hand, the vibration table of the present invention is used as a vibration element.

  A vibration table 1 shown in FIG. 1 includes a stainless block 2 and a laminated piezoelectric element 3. The stainless steel block 2 is provided with four bolt holes 4 for attachment to a processing apparatus. Block 2 is created by electric discharge machining. The block 2 is provided with a space portion 7 in order to reduce the mass of the vibrating block at the center thereof. Further, the thin portion 8 is provided in order to increase the amount of displacement due to forced vibration. Further, a fixing portion 6 for fixing the multilayer piezoelectric element 3 and a movable fixing portion 5 for receiving the displacement of the multilayer piezoelectric element 3 are provided. In addition, although the epoxy resin was used for the method of fixing the laminated piezoelectric element 3 to the movable fixing portion 5 and the fixing portion 6, a mechanical fixing method using screws may be used.

Next, an operation method of the vibration table 1 will be described. A voltage that changes with time is applied to the multilayer piezoelectric element 3. A voltage application method will be described with reference to FIG. In each of (A), (B), and (C), the vertical axis represents the magnitude of the applied voltage, and the horizontal axis represents the time axis.
The method (A) is a method of applying a rectangular voltage. In the figure, the time during which the voltage is applied during one period and the time during which the voltage is not applied are the same, but this ratio is changed. It is also possible. Further, in the figure, only three cycles are drawn for (A), (B), and (C) in order to simplify the drawing. Actually, it is necessary to apply a voltage under the condition of 100 cycles or more and 15000 cycles or less per second in order to make the vibration machining effect appear.
The method (B) is a method of applying a triangular wave voltage. Of course, a sawtooth voltage similar to this triangular wave may be used.
The method (C) is a method of applying a sine wave voltage. Here, there is also a method of shifting the center voltage by applying a DC voltage to a sine wave voltage. This is because the polarization of the piezoelectric material of the multilayer piezoelectric element 3 does not deteriorate.
A typical voltage waveform that changes with time is shown above, but other waveform may be used as long as it has a periodic voltage waveform.

  When a periodic voltage is applied to the multilayer piezoelectric element 3, the multilayer piezoelectric element 3 is displaced in the length direction. Then, the stacked piezoelectric element 3 is displaced by the fixing portion 6 and the movable fixing portion 5 shown in FIG. The fixing portion 6 is hardly displaced because the stainless steel is thick. On the other hand, the movable fixing portion 5 receives the displacement of the multilayer piezoelectric element 3 almost as it is due to the effect of the thin portion 8. Therefore, the table surface of the block vibrates in the same arrow direction as the displacement direction of the multilayer piezoelectric element 3.

  Here, the laminated piezoelectric element 3 will be described with reference to FIG. The laminated piezoelectric element 3 is also called a piezoelectric actuator, and is described in, for example, pages 60 to 70 of “New Actuator Manual for Precision Control, 1994, Fuji Techno System Co., Ltd.”. The multilayer piezoelectric element 3 is formed by laminating a plurality of piezoelectric ceramics, and the uppermost and lowermost piezoelectric ceramics are inactive portions 9 that are not polarized. The other piezoelectric ceramic is a polarized portion 10 that is polarized. Moreover, the polarization directions of the piezoelectric ceramics adjacent to each other are opposite to each other. There is an internal electrode 11 between each piezoelectric ceramic, and a glass insulator 13 is provided to connect the internal electrode 11 every other layer. There is an external electrode 12 for connecting the internal electrode 11 every other layer. By applying a voltage to the external electrode 12, the laminated piezoelectric element 3 is displaced in the length direction.

The height of the vibration table shown in FIG. 1 can be reduced to 40 mm or less, and can be mounted on almost any processing apparatus.
Further, since the drive frequency can be varied, it is possible to operate at an optimum drive frequency depending on the material and shape of the workpiece.
Further, since the non-resonant drive is used, the table surface which is the surface of the block 2 uniformly vibrates longitudinally.

FIG. 3 is a perspective view showing an example of a vibration table having a second configuration according to the present invention. The table surface is configured to vibrate horizontally in two directions.
The vibration table 1 shown in FIG. 3 includes a stainless block 2 and laminated piezoelectric elements 3a, 3b, 3c, and 3d. The stainless steel block 2 is provided with eight bolt holes 4 for attachment to a processing apparatus. Block 2 is created by electric discharge machining. Further, the thin portion 8 is provided in order to increase the amount of displacement due to forced vibration. Further, a fixing portion 6 for fixing the multilayer piezoelectric element 3 and a movable fixing portion 5 for receiving the displacement of the multilayer piezoelectric element 3 are provided. In addition, although the epoxy resin was used for the method of fixing the laminated piezoelectric element 3 to the movable fixing portion 5 and the fixing portion 6, a mechanical fixing method using screws may be used.

Next, an operation method of the vibration table 1 will be described. A voltage that changes with time is applied to the multilayer piezoelectric element 3. The voltage application method is the same as that described in the vibration table of the first configuration.
In order to vibrate in the direction of arrow A in the figure, a time-varying voltage is applied to the multilayer piezoelectric element 3a. In order to vibrate in the direction of arrow B in the figure, a voltage that changes with time is applied to the multilayer piezoelectric element 3b.
Furthermore, the vibration of the circular locus of the arrow C is excited by setting the phase difference between the time-varying voltage applied to the laminated piezoelectric element 3a and the time-varying voltage applied to the laminated piezoelectric element 3b to 90 degrees. You can also.

Since arbitrary vibrations in the horizontal X direction, Y direction, and circular locus can be excited on such a table surface, the optimal vibration can be selected depending on the processing method of the processing apparatus, the shape of the workpiece, or the material. This is a feature of non-resonant vibration and cannot be performed with a conventional ultrasonic vibration table.
This is also a feature of non-resonant vibration, but the vibration of the table surface can be directly applied to the workpiece. On the other hand, in the conventional ultrasonic vibration table, the vibration in the horizontal direction on the table surface increases the loss of ultrasonic vibration between the table surface and the workpiece, the vibration propagating to the workpiece is considerably small, and the effect of the ultrasonic vibration table can hardly be exhibited. .

FIG. 4 is a perspective view showing an example of a vibration table having a third configuration according to the present invention. The table surface is configured to angularly vibrate in the θ direction.
A vibration table 1 shown in FIG. 4 includes a stainless block 2 and a laminated piezoelectric element 3. The stainless steel block 2 is provided with four bolt holes 4 for attachment to a processing apparatus. Block 2 is created by electric discharge machining. Further, the thin portion 8 is provided in order to increase the amount of displacement due to forced vibration. Further, a fixing portion 6 for fixing the multilayer piezoelectric element 3 and a movable fixing portion 5 for receiving the displacement of the multilayer piezoelectric element 3 are provided. In addition, although the epoxy resin was used for the method of fixing the laminated piezoelectric element 3 to the movable fixing portion 5 and the fixing portion 6, a mechanical fixing method using screws may be used.

Next, an operation method of the vibration table 1 will be described. A voltage that changes with time is applied to the multilayer piezoelectric element 3. The voltage application method is the same as that described in the vibration table of the first configuration.
In order to vibrate in the θ direction of the arrow in the figure, a voltage that changes with time is applied to the multilayer piezoelectric element 3.

  The vibration in the θ direction due to such non-resonant vibration can be directly propagated to the workpiece, which is a workpiece, while the ultrasonic vibration table using the conventional torsional vibration that excites the same vibration in the θ direction is used. The vibration propagating to the workpiece is small, and may change to various vibration modes depending on the shape and material of the workpiece.

It is also possible to perform vibrations in the X, Y, Z, and θ directions as a vibration table. The vibration table of the first configuration of the present invention is vibration in the Z direction, the vibration table of the second configuration of the present invention is vibration in the X and Y directions, and the vibration table of the third configuration of the present invention is Since these are vibrations in the θ direction, if they are stacked, it can be configured as a vibration table that vibrates in the X, Y, Z, and θ directions.
Further, if the first configuration, the second configuration, and the third configuration of the present invention are combined, a vibration stage that performs a desired vibration motion can be configured.

6 and 7 are perspective views showing an example of a vibration table having a fourth configuration according to the present invention. The table surface is configured to vibrate longitudinally in the same height direction as the displacement direction of the multilayer piezoelectric element 3.
The laminated piezoelectric element 3 is fixed to an stainless base base 14 with an epoxy resin, and a stainless steel table 15 is also mounted thereon. The laminated piezoelectric element 3 and the stainless steel table 15 are joined using an epoxy resin.

  Next, an operation method of the vibration table 1 will be described. A voltage that changes with time is applied to the multilayer piezoelectric element 3. The voltage application method is the same as that described in the vibration table of the first configuration.

  In this configuration, a large number of laminated piezoelectric elements 3 can be easily installed, so that the vibration power can be increased. For this reason, it becomes an optimal structure when the weight of the workpiece | work etc. which are mounted on a vibration table is large. Further, since it is non-resonant vibration, the vibration as it is propagates to the workpiece placed on the table.

  Although a multilayer piezoelectric element has been described as the vibration source of the present invention, it goes without saying that an element using a giant magnetostrictive material having the same function is also possible. As for the giant magnetostrictive material, for example, “Ultrasonic Handbook” (Maruzen Co., Ltd., 1999, p87 to p91) has a detailed description.

  The vibration table of the present invention can be used as a machining table used in machining facilities and the like.

It is a perspective view which shows the structure of an example of the vibration table of the 1st structure of this invention. It is a perspective view of the lamination type piezoelectric element used for the vibration table of the present invention. It is a perspective view which shows an example of the vibration table of the 2nd structure of this invention. It is a perspective view which shows an example of the vibration table of the 3rd structure of this invention. It is a figure which shows the voltage waveform applied to a lamination type piezoelectric element. It is a perspective view which shows a part of example of the vibration table of the 4th structure of this invention. It is a perspective view which shows an example of the vibration table of the 4th structure of this invention. It is a figure which shows one example of the conventional ultrasonic vibration table.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vibration table 2 Block 3 Laminated piezoelectric element 4 Bolt hole 5 Movable fixed part 6 Fixed part 7 Space part 8 Thin part 9 Inactive part 10 Polarizing part 11 Internal electrode 12 External electrode 13 Insulator 14 Base stand 15 Table

Claims (5)

In a table device that fixes and holds a workpiece to be processed by being attached to a processing device, a vibration table device is characterized in that a laminated piezoelectric element is attached to the table and the table device is vibrated by applying a voltage to the laminated piezoelectric element. . 2. The vibration table device according to claim 1, wherein a voltage applied to the multilayer piezoelectric element changes from 100 times to 15000 times per second. 2. The vibration table device according to claim 1, wherein the displacement direction of the multilayer piezoelectric element is perpendicular to the table surface. The vibration table device according to claim 1, wherein the displacement direction of the multilayer piezoelectric element is parallel to the table surface. Use a vibration table device that vibrates in a direction perpendicular to the table surface, a pseudo-motion table device that vibrates in a direction parallel to the table surface, or a vibration table device that vibrates angularly with respect to the central axis on the table surface, or a combination of any two of them. The vibration table device according to claim 1, wherein:

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