JP2005212067A - Ultrasonic polishing method and its device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic polishing method for uniformly and accurately polishing a surface formed with complicated shapes and fine irregular shapes and its device. <P>SOLUTION: After a polishing object surface 11 of a workpiece 1 is transferred to viscous fluid 3 stored into a container 4, polishing fluid 2 mixed with abrasive agent is injected into a transferred recessed part, the workpiece 1 is placed on the polishing fluid 2, fixed pressure is applied to the workpiece 1, and ultrasonic vibration is impressed from a vibrator 12 excited from an ultrasonic oscillator 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ultrasonic polishing method and apparatus for polishing an object to be polished by ultrasonic vibration, and more particularly to an ultrasonic polishing method and apparatus for accurately polishing the surface of an object having a complicated shape. It is.

  As a conventional ultrasonic polishing process, an object to be polished is immersed in a polishing liquid mixed with an abrasive, and ultrasonic vibration is applied in a sealed state, and the flow of the abrasive is promoted by vibration of bubbles generated by cavitation. A method of polishing an object to be polished is known (see Patent Document 1).

  In the above prior art, as shown in FIG. 5, an object to be polished 103 is accommodated in a container 101, an abrasive liquid 104 mixed with an abrasive is supplied into the container 101, and the object to be polished 103 becomes an abrasive liquid. Soaked in water. The opening of the container 101 is closed with a lid 105 via a packing 106, and the lid 105 is brought into close contact with the container 101 with a fastener 107 to make the inside of the container 101 airtight. Next, the air pressure adjusting valve 112 is adjusted to supply air from the air compressor 113 into the container 101, and the pressure in the container 101 is increased to a predetermined value. When the ultrasonic oscillator 110 is operated in this state, the ultrasonic vibrator 109 vibrates ultrasonically, the ultrasonic vibration is transmitted to the polishing liquid 104, and a straight flow is generated in the traveling direction of the ultrasonic wave. Further, the flow of the polishing liquid 104 is promoted by the effect of the generation and bursting of cavitation based on ultrasonic vibration and the flow of bubbles generated by the cavitation to generate a small flow in the vicinity of the workpiece 103. With this configuration, since the cavitation is generated and ruptured with high energy, the surface of the object to be polished is polished.

  In addition, in order to polish the concave portion of the object to be polished, a liquid containing abrasive grains is solidified or gelled according to the shape of the object to be polished, and a relative motion is given to the object to be polished. A polishing method for polishing is known (see Patent Document 2).

Like the procedure shown in the order of (1) to (6) in FIG. 6, a magnetic fluid 201 containing a predetermined amount of magnetic abrasive grains 203 is poured into the processed surface 204 ′ of the workpiece 204, and the processed surface 204 ′. The interior is filled (1). When this object 204 is placed on the magnetic field generating means 205, the arrangement and distribution density of the magnetic abrasive grains 203 mixed in the liquid 202 can be controlled (2). In this state, the magnetic fluid 201 is frozen and solidified with the magnetic abrasive grains 203 controlled to the state (2) by placing the workpiece 204 in a low temperature environment (3). Next, the workpiece 204 is heated by the heater 206 to a degree slightly higher than the melting point of the magnetic fluid 201, and the contact surface of the magnetic fluid 201 with the processed surface 204 'is melted thinly (4). When the fixing means 207 is driven into the solidified magnetic fluid 201 (5) and a relative motion is given to the workpiece 204 (6), the processed surface 204 ′ of the workpiece 204 is polished.
Japanese Patent Laid-Open No. 02-030463 (pages 5-6, FIG. 1) Japanese Patent Laid-Open No. 11-165252 (pages 4-5, FIG. 1)

  However, in the prior art disclosed as Patent Document 1, since the polishing effect is obtained by using the energy of cavitation generation and rupture even when pressure is applied to the polishing liquid 104, undulations remain on the surface in the pre-processing. This is similar to lapping with a soft cloth affixed to the surface plate, and the appearance is improved, but fine irregularities are not removed. There was a problem.

  Further, in the conventional technique disclosed as Patent Document 2, the bottom surface of the concave portion or the rising portion of the convex portion in the fine concave and convex shape is difficult to polish, and when the object to be polished has a complicated shape, the stroke of the relative motion is reduced. Therefore, there has been a problem that the polishing rate becomes slow. In addition, since a corner having a shape such as a groove bottom surface is difficult to polish in a three-dimensional stroke as compared with other portions, there is a problem that cannot be applied to ultra-precision polishing.

  An object of the present invention is to provide an ultrasonic wave that can polish a surface of an object having a complicated shape or a surface of an object having a fine concavo-convex shape in a short period of time with high precision. A polishing method and an apparatus therefor are provided.

  In order to achieve the above object, the ultrasonic polishing method according to the first invention of the present application accommodates a viscous fluid adjusted to a predetermined viscosity in a container, and an abrasive having a viscosity lower than that of the viscous fluid is mixed thereon. Injecting the polishing fluid, placing the object to be polished so that the surface to be polished is in contact with the polishing fluid, sealing the inside of the container, and applying a certain pressure to the object to be polished, the polishing fluid and the viscous fluid Ultrasonic vibration is applied to the object to be polished, and the surface to be polished is ultrasonically polished with a polishing fluid.

  According to the above polishing method, since the ultrasonic vibration is applied while pressurizing the contents in the container in a state where the polishing target surface of the object to be polished is in contact with the polishing fluid, the polishing fluid is interposed between the viscous fluid and the polishing target surface. The polishing target surface is pressed against the layered polishing fluid, and the polishing fluid penetrates into the complicated shape portion or fine uneven shape portion of the polishing target surface, and ultrasonic vibration is applied to cause the polishing fluid to flow. The surface to be polished is polished by an abrasive in the polishing fluid.

  In the above polishing method, the temperature-controlled cooling water is circulated in the container to maintain the viscosity of the polishing fluid and the viscous fluid, and ultrasonic polishing is performed, so that the polishing fluid due to the change in viscosity is removed from the surface to be polished. Ultrasonic polishing can be performed while maintaining the state of being interposed in layers without moving.

  In addition, when ultrasonic polishing is performed so that the viscous fluid and the polishing fluid are partitioned by a film-like body, mixing of the polishing fluid and the viscous fluid can be effectively prevented.

  In addition, the surface of the object to be polished is pressed against the viscous fluid stored in the container to transfer the shape of the surface to be polished, the shape is transferred, and then the polishing fluid is injected, and the object to be polished is arranged on the polishing fluid. Then, when ultrasonic polishing is performed, the polishing fluid comes into contact with all the polishing target surfaces even on the polishing target surface having a complicated shape, and can be processed into a uniform polishing state.

  The ultrasonic polishing apparatus according to the second invention of the present application is such that a viscous fluid adjusted to a predetermined viscosity, a polishing fluid having a lower viscosity than the viscous fluid and mixed with an abrasive, and a surface to be polished are in contact with the polishing fluid. A container for accommodating the objects to be polished arranged in this order, a lid for closing the opening of the container, a pressurizing means for applying a predetermined pressure to the contents in the container, and a pressure applied by the pressurizing means. And ultrasonic vibration means for applying ultrasonic vibration to the object to be polished.

  According to the above configuration, since the ultrasonic vibration is applied from the ultrasonic vibration means while pressurizing the contents in the container with the pressurizing means with the polishing target surface in contact with the polishing fluid, the viscosity is The surface to be polished is pressed against the polishing fluid that is layered between the fluid and the surface to be polished, and the polishing fluid penetrates into the complicated shape portion or fine uneven shape portion of the surface to be polished, and ultrasonic vibration is applied. As a result, the polishing fluid flows and the surface to be polished is polished by the polishing material in the polishing fluid.

  In the above configuration, it is desirable to provide a cooling means for maintaining the viscous fluid and the polishing fluid at a predetermined temperature. The viscous fluid and the polishing fluid generate heat due to ultrasonic vibration, and the viscosity is changed so that the polishing fluid is layered on the viscous fluid. The state where there is no collapse.

  According to the present invention, the ultrasonic vibration is applied from the ultrasonic vibration means while pressurizing the contents in the container by the pressurizing means with the surface to be polished being in contact with the polishing fluid. The fluid also penetrates into a complicated shape portion or a fine uneven shape portion on the surface to be polished, and these portions are also reliably polished and finished in a uniform polished state in a short time.

  FIG. 1 shows the configuration of an ultrasonic polishing apparatus that ultrasonically polishes the surface of an object to be polished by the ultrasonic polishing method according to the first embodiment. The procedure of the ultrasonic polishing method using this apparatus will be described below in order.

  First, as shown in FIG. 3, the viscous fluid 3 is put into the container 4, and the object to be polished 1 is placed on the container 4 so that the surface 11 to be polished is in contact with the viscous fluid 3. The object to be polished 1 is pressed against the viscous fluid 3 by the pressure rod 10 extending from the ultrasonic oscillator 7, and the shape of the surface 11 to be polished of the object 1 to be polished is pressed against the viscous fluid 3. Transcript. This transfer does not need to be transferred to a fine shape formed on the surface 11 to be polished, and it is only necessary to transfer the general shape of the surface 11 to be polished. Therefore, it is desirable to set the viscosity of the viscous fluid 3 high. .

  After the shape of the surface 11 to be polished is transferred to the viscous fluid 3 by the transfer step, the object 6 is removed from the container 4 by opening the lid 6, and the polishing material is mixed in the transfer recess of the viscous fluid 3. A predetermined amount of fluid 2 is injected. The viscosity of the polishing fluid 2 is set to a viscosity that is lower than the viscosity of the viscous fluid 3 and can enter a fine recess formed in the surface 11 to be polished.

  Next, the surface 11 to be polished of the workpiece 1 is returned to the container 4 so as to be in contact with the polishing fluid 2, the opening of the container 4 is closed with the lid body 6, and the pressure bar (pressurization) of the ultrasonic oscillator 7 is closed. 1) By pressing the object 1 to be polished against the polishing fluid 2 by the means 10, the polishing fluid 2 forms a layer between the surface 11 to be polished of the object 1 and the viscous fluid 3 as shown in FIG. The state to do is obtained. The polishing fluid 2 enters a fine recess formed on the surface 11 to be polished, and comes into contact with the entire surface 11 to be polished.

  In the state shown in FIG. 1, when the vibrator (ultrasonic vibration means) 12 is excited from the ultrasonic oscillator 7 and ultrasonic vibration is applied to the workpiece 1, the polishing fluid 2 is polished with the viscous fluid 3 by the ultrasonic vibration. Since it flows between the target surface 11, the polishing target surface 11 is polished by the abrasive mixed with the polishing fluid 2. At this time, since the polishing direction can be changed by controlling the amplitude direction of the ultrasonic vibration, when the surface 11 to be polished is ground, as shown in FIG. If the amplitude direction is changed, it is easy to remove the grinding streaks, the surface roughness can be easily improved, and the polishing rate can be improved.

  During the polishing process, since the polishing fluid 3 and the viscous fluid 3 generate heat due to the ultrasonic vibration, the cooling water controlled at a constant temperature by the temperature control device (cooling means) 9 is circulated in the container 4. The viscosity of the polishing fluid 2 and the viscous fluid 3 can be controlled so as not to change due to a temperature rise.

  FIG. 2 shows the configuration of an ultrasonic polishing apparatus according to the second embodiment. A film (film-like body) 14 is interposed between the polishing fluid 2 and the viscous fluid 3, and the polishing fluid 2 and the viscous fluid. 3 is not mixed. Other configurations are the same as those of the first embodiment described above, and common components are denoted by the same reference numerals, and description thereof is omitted.

  In this configuration, as shown in FIG. 3, after the shape of the surface 11 to be polished of the workpiece 1 is transferred to the viscous fluid 3 put into the container 4, the shape is transferred to the surface of the viscous fluid 3 to which the shape is transferred. An ultrathin film 14 is placed, and a certain amount of polishing fluid 2 is injected thereon. The film 14 may be an extremely thin elastic body such as a rubber-like material.

  As described above, according to the present invention, it is possible to perform ultra-precision polishing of a surface on which a complicated shape or a fine uneven shape is formed, and it can be applied to polishing of an optical device or a precision molding die. And effective.

Sectional drawing which shows the structure of the ultrasonic polishing apparatus which concerns on 1st Embodiment. Sectional drawing which shows the structure of the ultrasonic polishing apparatus which concerns on 2nd Embodiment. Sectional drawing explaining the process of transferring the grinding | polishing target surface of a to-be-polished object. The figure which shows the relationship between the amplitude direction of ultrasonic vibration, and a grinding | polishing direction. Sectional drawing which shows the structure of the ultrasonic polishing apparatus which concerns on a prior art. The schematic diagram which shows the procedure of the grinding | polishing method which concerns on a prior art later on.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 To-be-polished object 2 Polishing fluid 3 Viscous fluid 4 Container 6 Lid body 7 Ultrasonic oscillator 9 Temperature control apparatus (cooling means)
10 Pressurizing rod (Pressurizing means)
11 Surface to be polished 12 Vibrator (Ultrasonic vibration means)
14 Film (Membrane)

Claims (6)

A viscous fluid adjusted to a predetermined viscosity is contained in a container, and a polishing fluid having a viscosity lower than that of the viscous fluid and mixed with an abrasive is injected onto the container, and the surface to be polished is in contact with the polishing fluid. A polishing object is arranged to seal the inside of the container, and ultrasonic vibration is applied to the object to be polished in a state where a certain pressure is applied to the object to be polished, the polishing fluid and the viscous fluid, and the surface to be polished is polished by the polishing fluid. An ultrasonic polishing method comprising performing ultrasonic polishing. The ultrasonic polishing method according to claim 1, wherein ultrasonic polishing is performed by circulating cooling water whose temperature is controlled in the container to maintain the viscosity of the polishing fluid and the viscous fluid. The ultrasonic polishing method according to claim 1, wherein the viscous fluid and the polishing fluid are partitioned by a film-like body. Claim: The surface of the object to be polished is pressed against the viscous fluid stored in the container to transfer the shape of the surface to be polished, the shape is transferred, the polishing fluid is injected, and the object to be polished is disposed on the polishing fluid. Item 4. The ultrasonic polishing method according to any one of Items 1 to 3. A container containing in order of a viscous fluid adjusted to a predetermined viscosity, a polishing fluid having a lower viscosity than the viscous fluid and mixed with an abrasive, and an object to be polished arranged so that the surface to be polished is in contact with the polishing fluid; A lid that closes the opening of the container; a pressurizing unit that applies a predetermined pressure to the contents in the container; and an ultrasonic wave that applies ultrasonic vibration to the object to be polished while being pressurized by the pressurizing unit. An ultrasonic polishing apparatus comprising a sonic excitation means.   The ultrasonic polishing apparatus according to claim 5, further comprising a cooling unit that maintains the viscous fluid and the polishing fluid at a predetermined temperature.

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