JP2012223823A - Polishing method, and nozzle structure for blasting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit generation of a cutting force perpendicular to a surface of a workpiece and obtain a horizontal cutting force, in polishing performed by imparting kinetic energy to an abrasive using a compressed gas flow.SOLUTION: A compressed gas containing no abrasive is ejected toward a surface of a workpiece W from an accelerated flow generation nozzle 10, an accelerated flow S is generated along the surface of the workpiece W, the abrasive 30 is introduced into an abrasive introduction path 20 opened toward the surface of the workpiece W at the generation position of this accelerated flow S, preferably introduced together with the compressed gas, the abrasive 30 is merged with the accelerated flow S, the abrasive 30 is slid along the surface of the workpiece W, thereby exerting the horizontal cutting force on the surface.

Description

  The present invention relates to a polishing method and a nozzle structure of a blasting apparatus for realizing the polishing method, and more specifically, a polishing method for a workpiece performed by applying kinetic energy to an abrasive by a compressed gas flow, and The present invention relates to a structure of a nozzle portion of a blasting device for realizing a polishing method by a blasting device.

  Known polishing methods for improving the flatness of the workpiece surface and processing it into a smooth surface such as a mirror surface include, for example, polishing with abrasive paper or polishing cloth, polishing with buffing, lapping, or contact with rotating abrasive grains. There are polishing, super finishing processing for polishing a workpiece by contact with abrasive grains subjected to ultrasonic vibration, and the like.

  On the other hand, blasting, in which cutting is performed by spraying an abrasive together with a compressed fluid, for example, compressed air, on the surface of the workpiece, is generally related to a processing technique using an abrasive. It is not used for polishing to improve flatness on the surface of the workpiece.

  This is because the abrasive material injected by the blasting process together with the compressed gas collides with the surface of the workpiece, and the surface of the workpiece is processed by the energy at the time of the collision. Since the cutting force in the direction perpendicular to the surface of W (depth) is exerted, as a result, cutting proceeds while inheriting the morphological features of the irregularities originally formed on the surface of the workpiece as shown in FIG. However, it is difficult to obtain a flat surface for a large amount of cutting.

  In blasting, cutting is performed by the impact energy of the abrasive as described above, so that new irregularities are formed on the surface of the workpiece by cutting or deformation associated with the collision of abrasive grains to make a satin finish. This also makes flattening difficult.

  As described above, in the conventional general blasting method, it is difficult to flatten the surface of the workpiece, in particular, with high precision like a mirror surface. It has also been proposed to solve the problem and suppress the occurrence of matte finish on the surface of the workpiece by blasting so that the surface can be processed into a flat surface such as a mirror surface.

  As an example of such a blasting method, the applicant applied an abrasive having a structure in which abrasive grains are dispersed in a base material that is an elastic body (in this specification, an abrasive having such a structure is referred to as “elastic polishing”. Material)) is injected or projected onto the surface of the workpiece at a predetermined angle of incidence, so that the energy at the time of collision is absorbed by the plastic deformation of the elastic body, thereby suppressing the occurrence of satin and elastic. It has been proposed that blasting can be used to improve flatness by sliding an abrasive along a surface to be processed (Patent Document 1).

  Also, the abrasive together with the compressed fluid is applied to the processed surface of the workpiece, 0 <V · sin θ ≦ 1/2 · V (V = velocity of the abrasive in the injection direction, θ = polishing to the processed surface of the workpiece) Even if existing abrasives (abrasive grains) are used under the condition of the angle of incidence of the material, the flatness is improved by generating a jet of abrasive along the surface of the workpiece. It has also been proposed to be able to perform (Patent Document 2).

JP 2006-159402 A Japanese Patent Laid-Open No. 2005-022015

  Among the conventional polishing methods, in polishing with a polishing cloth or paper, lapping, polishing with a grindstone, etc., a polishing material with a small particle size has a weak polishing power. The polishing process is necessary and the work is complicated.

  Moreover, although the polishing amount depends on the processing pressure, if the processing pressure is set low in order to avoid excessive processing distortion, the processing speed is lowered and the productivity is low.

  On the other hand, if high processing pressure is applied, grinding and polishing cracks may occur.

  In addition, since the processing strain is generated in the surface layer of the workpiece to be polished in a state where the processing pressure is applied, as described above, when the workpiece is a silicon wafer, for example, the complete processing near the wafer surface is performed. In order to secure the crystal layer, it may be necessary to remove the processing strain generated during the polishing process. For this reason, the wafer polished after the polishing process may be heat treated, or the surface layer may be formed using acid or alkali. A process such as removal is required. Further, when removing the surface layer using acid or alkali, it is necessary to appropriately treat the waste liquid such as acid or alkali used at this time.

  On the other hand, in the methods introduced as the above-mentioned Patent Documents 1 and 2, it is difficult for extra stress to enter the workpiece after polishing as compared with lapping, which is a polishing method that is generally performed conventionally. In addition, it is possible to prevent distortion and the like from occurring after processing.

  However, in the blasting method introduced as Patent Document 1, the above-mentioned elastic abrasive is used to prevent the occurrence of matte on the surface of the workpiece and to slide the abrasive along the workpiece surface. Therefore, the energy at the time of collision is absorbed by the plastic deformation of this elastic abrasive, and it is essential to use an abrasive with a special structure.

  In the blasting method introduced as Patent Document 2, even when a normal abrasive (abrasive grain) is used without using a special abrasive by setting the injection condition of the abrasive appropriately. The abrasive can be slid along the surface of the workpiece, and the workpiece can be polished relatively easily by blasting.

  However, with this method, when the abrasive material collides, the horizontal component is sufficiently increased with respect to the vertical component of the force acting on the workpiece surface, so that the surface of the workpiece surface due to the impacted abrasive grains is generated. In order to prevent this, the vertical component cannot be removed unless the incident angle θ is set to 0 (zero).

  If the incident angle θ is to be close to 0 (zero) in order to reduce the vertical component described above, the injection nozzle is inclined with respect to the surface of the workpiece, or is injected from the injection nozzle. An auxiliary device or the like for guiding the jet flow to the flow along the surface of the workpiece is required (see FIGS. 3 to 13 of Patent Document 1), and it may be difficult to apply depending on the shape of the workpiece. Is done.

  In the above description, as an example of “polishing” of a workpiece, the point of improving (smoothing) flatness is mainly described. However, in addition to improving (smoothing) flatness, for example, the original surface For other polishing operations such as reducing the smoothness (roughening) and removing coatings on the surface, etc., the vertical direction relative to the surface of the workpiece can be achieved by a relatively simple operation similar to blasting. If polishing with reduced cutting force can be performed, there are advantages such as reduction of damage to the workpiece and suppression of an increase in the amount of cutting more than necessary.

  Therefore, the present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art, and as in the known blasting method, polishing is performed by applying kinetic energy to the abrasive by a compressed gas flow. Even if normal abrasives (abrasive grains) are used without using specially structured abrasives such as elastic abrasives, cutting force in the direction perpendicular to the surface of the workpiece is generated. In addition to suppressing the horizontal direction, the cutting force in the horizontal direction can be exerted to improve the surface flatness of the workpiece, adjust the surface roughness, remove the surface coating, etc. An object of the present invention is to provide a polishing method that can be performed, and a nozzle structure of a blasting apparatus used in the polishing method.

To achieve the above object, the polishing method of the present invention introduces and injects a compressed gas that does not contain an abrasive material, which is the injection fluid P1, into the acceleration flow generating nozzle 10 arranged toward the surface of the workpiece W. Generating an acceleration flow S along the surface of the workpiece W;
By introducing the abrasive 30 into the abrasive introduction path 20 opening toward the surface of the workpiece W at the position where the acceleration flow S is generated, the abrasive 30 is joined to the acceleration flow S, and the polishing is performed. The material 30 is slid along the surface of the workpiece W (Claim 1).

  In the above polishing method, the abrasive 30 is mixed with the carrier fluid P2, which is a compressed gas having a pressure lower than that of the jet fluid P1 introduced into the acceleration flow generating nozzle 10, and introduced into the abrasive introduction passage 20. (Claim 2).

  In this case, it is preferable to set the carrier fluid P2 to a pressure equal to or less than two-thirds of the jet fluid P1.

  Further, in the above-described polishing method, the gap 21 between the nozzle 11 of the acceleration flow generating nozzle 10 and the surface of the workpiece W is between the opening 21 of the abrasive introduction path 20 and the surface of the workpiece W. It is preferable that the interval (δ1 + δ2) is widened (see claim 4: see FIG. 3).

  More preferably, the interval δ1 between the injection port 11 of the acceleration flow generating nozzle 10 and the surface of the workpiece W is set to 0.5 to 3.0 mm, and the opening 21 of the abrasive introduction path 20 and the workpiece are processed. The interval (δ1 + δ2) between the surfaces of the workpiece W is formed to be 1.0 to 3.0 mm wider than the interval δ1 between the injection port 11 of the acceleration flow generating nozzle 10 and the surface of the workpiece W (Claim 5). ).

Further, the nozzle structure (blast nozzle 1) of the blasting apparatus of the present invention for realizing the above polishing method is a compression that does not include an abrasive supplied as a jet fluid P1 from a compressed gas supply source (not shown). An acceleration flow generating nozzle 10 for injecting gas toward the surface of the workpiece W to generate an acceleration flow S along the surface of the workpiece W;
An abrasive introduction path 20 is provided that opens toward the surface of the workpiece W at the position where the acceleration flow S is generated and into which the abrasive 30 from an abrasive supply source (not shown) is introduced. It is characterized (claim 6).

  In the nozzle structure described above, an abrasive supply source for supplying the abrasive 30 as a mixed fluid with the carrier fluid P2 that is a compressed gas through the abrasive introduction path 20 (for example, an abrasive tank of a direct pressure blasting apparatus: It is good also as what communicates with (not shown).

  The arrangement of the acceleration flow generation nozzle 10 and the abrasive introduction path 20 in the nozzle structure is realized by arranging the end of the acceleration flow generation nozzle 10 on the injection port 11 side in the abrasive introduction path 20. (Claim 8: See FIGS. 1 to 3).

  Further, instead of the above configuration, the injection port 11 of the acceleration flow generation nozzle 10 may be formed in a slit shape, and the opening 21 of the abrasive material introduction path 20 may be arranged in parallel with the injection port 11 ( (Claim 9: see FIG. 4). In this case, openings 21 of the abrasive introduction path 20 may be further arranged on both sides of the injection port 11 of the acceleration flow generation nozzle 10 (Claim 10: FIG. 5). reference).

  In the nozzle structure, the injection port 11 of the accelerating flow generating nozzle 10 is protruded in the injection direction by 1.0 to 3.0 mm (corresponding to δ2 in FIG. 3) with respect to the opening 21 of the abrasive introduction passage 20. (Claim 11).

  With the configuration of the present invention described above, the following remarkable effects can be obtained according to the polishing method of the present invention.

  By injecting the jet fluid P1 onto the surface of the workpiece W and introducing the abrasive 30 through the separately provided paths of the acceleration flow generation nozzle 10 and the abrasive introduction path 20, the workpiece W is obtained. After generating the acceleration flow S along the machining surface, the abrasive 30 is joined to the acceleration flow S so that the abrasive 30 collides with the surface of the workpiece in the vertical direction. It was possible to slide along the surface of the workpiece W together with the accelerating flow S.

  As a result, generation of a cutting force acting in a direction perpendicular to the surface of the workpiece W is suppressed, and a horizontal cutting force is generated by sliding of the abrasive 30 to be applied to the workpiece W during polishing. Provides a polishing method that can greatly reduce damage and is applicable to polishing for the purpose of improving flatness (smoothing), which was difficult with conventional blasting. We were able to.

  In particular, the abrasive 30 is transported as a mixed fluid with a transport fluid P2 having a pressure lower than that of the jet fluid P1, and preferably with a transport fluid P2 having a pressure less than two-thirds of that of the jet fluid P1. It is possible to smoothly introduce the abrasive 30 while greatly suppressing the abrasive 30 from exerting a cutting force in the vertical direction with respect to the surface of the workpiece W. Since the carrier fluid P2 discharged from the opening 21 toward the acceleration flow S acts to press the acceleration flow S toward the surface of the workpiece W, the acceleration flow S is applied to the workpiece W. The separation from the surface could be prevented, and the followability of the acceleration flow S to the surface of the workpiece W could be improved.

  Furthermore, the interval (δ1 + δ2) between the opening 21 of the abrasive introduction path 20 and the surface of the workpiece W is made wider than the interval δ1 between the injection port 11 of the acceleration flow generating nozzle 10 and the surface of the workpiece W. Preferably, when the interval δ1 is set to 0.5 to 3.0 mm and the interval δ2 is set to 1.0 to 3.0 mm, the jet fluid P1 injected from the acceleration flow generating nozzle 10 passes through the interval δ1. The acceleration flow S is preferably a flow along the surface of the workpiece W, and the distance (δ1 + δ2) between the abrasive introduction path 20 and the surface of the workpiece W, which is formed wider than the interval δ1. By being introduced, the flow of the acceleration flow S is not obstructed by the presence of the abrasive introduction path 20, and the acceleration flow S and the abrasive 30 can be suitably merged at this position.

  In the above-described method, the compressed gas supplied as the jet fluid P1 from the compressed gas supply source (not shown) is sprayed toward the surface of the workpiece W, and the surface of the workpiece W is aligned. An acceleration flow generating nozzle 10 for generating the acceleration flow S, an opening 30 toward the surface of the workpiece W at the generation position of the acceleration flow S, and an abrasive 30 from an abrasive supply source (not shown) are provided. This was realized by the nozzle structure (blast nozzle 1) of the blast processing apparatus provided with the abrasive introduction path 20 to be introduced.

  In this nozzle structure, in the configuration in which the abrasive introduction path 20 communicates with an abrasive supply source (not shown) that supplies the abrasive 30 as a mixed fluid with the carrier fluid P2 that is a compressed gas, the abrasive 30 As described above, the accelerating flow S is pressed against the surface of the workpiece by the conveying fluid, so that the accelerating flow S is preferably prevented from separating from the surface. I was able to.

  Further, in the configuration in which the end of the acceleration flow generation nozzle 10 on the injection port 11 side is disposed in the abrasive introduction path 20 (see FIGS. 1 to 3), the entire circumference of the injection port 11 of the acceleration flow generation nozzle 10 As a result, the abrasive 30 could be slid along the surface of the workpiece W, and the processing range could be widened.

  Further, in the configuration in which the injection port 11 of the acceleration flow generating nozzle 10 has a slit shape (see FIGS. 4 and 5), the polishing process can be simultaneously performed over a wide range corresponding to the length of the slit. In particular, in the configuration in which the openings 21 of the abrasive introduction path 20 are provided on both sides of the injection port 11 of the acceleration flow generation nozzle 10 (see FIG. 5), the opening of the nozzle 10 is centered on the acceleration flow generation nozzle 10. The polishing process could be performed simultaneously in two directions of the width direction, and efficient processing was realized.

The schematic sectional drawing which shows the structural example of the nozzle structure (blast nozzle) used for the grinding | polishing method of this invention. II-II sectional view taken on the line of FIG. The expanded sectional view of the blast nozzle tip part. It is explanatory drawing which shows the modification of the front-end | tip part of a blast nozzle, (A) is side surface sectional drawing, (B) is the BB sectional drawing of (A). It is explanatory drawing which shows the modification of the front-end | tip part of a blast nozzle, (A) is side surface sectional drawing, (B) is the BB sectional drawing of (A). Explanatory drawing which showed typically the cutting process of the surface of a workpiece by the method of this invention. Explanatory drawing of RMS (root mean square roughness). It is the surface electron micrograph of an untreated test piece (soda glass: mirror surface), (A) is a plane image, (B) is a three-dimensional image. It is the surface electron micrograph of the soda glass after the process by the method (Example 1) of this invention, (A) is a plane image, (B) is a stereo image. It is the surface electron micrograph of the soda glass after the process by the known blast process (comparative example 1), (A) is a plane image, (B) is a three-dimensional image. It is the surface electron micrograph of the soda glass after the process by the method (Example 2) of this invention, (A) is a plane image, (B) is a stereo image. It is the surface electron micrograph of an untreated test piece (aluminum alloy: hairline processed product), (A) is a plane image, (B) is a three-dimensional image. It is the surface electron micrograph of the aluminum alloy after the process by the method (Example 3) of this invention, (A) is a plane image, (B) is a stereo image. It is the surface electron micrograph of the aluminum alloy after the process by the known blast processing (Comparative example 2: injection pressure 0.2MPa), (A) is a plane image, (B) is a three-dimensional image. It is the surface electron micrograph of the aluminum alloy after the process by the known blasting (comparative example 3: injection pressure 0.4MPa), (A) is a plane image, (B) is a three-dimensional image. It is the surface electron micrograph of the aluminum alloy after the process by the method (Example 4) of this invention, (A) is a plane image, (B) is a stereo image. It is the surface electron micrograph of the aluminum alloy after the process by the method (Example 5) of this invention, (A) is a plane image, (B) is a stereo image. Explanatory drawing which showed typically the mode of the cutting in known blasting.

  Next, embodiments of the present invention will be described below with reference to the accompanying drawings.

[Blast nozzle]
Reference numeral 1 in FIG. 1 denotes a blast nozzle used in the polishing method of the present invention. This blast nozzle 1 is connected to a known blast processing apparatus (not shown) having a compressed gas supply source and an abrasive supply source. By attaching and using, the polishing method of the present invention can be realized.

  The blast nozzle 1 communicates with a compressed gas supply source provided in a blasting apparatus (not shown), and injects compressed gas introduced as an injection fluid P1 from the compressed gas supply source toward the surface of the workpiece W. Then, the acceleration flow generating nozzle 10 for generating the acceleration flow S flowing along the surface of the workpiece W and the abrasive 30 from an unillustrated abrasive supply source (for example, an abrasive tank) are introduced to accelerate the acceleration. A polishing material introduction path 20 that joins the flow S is provided, and the opening 21 of the polishing material introduction path 20 is arranged toward the surface of the workpiece W at the position where the acceleration flow S is generated. The abrasive introduced into the path 20 is merged with the acceleration flow S so that the surface of the workpiece W can be slid.

  In the illustrated embodiment, the acceleration flow generation nozzle 10 is formed as a cylindrical nozzle, and the abrasive introduction path 20 has a substantially cylindrical shape having an inner diameter that is larger than the outer diameter of the acceleration flow generation nozzle 10. And a part of the tip side of the acceleration flow generating nozzle 10 is arranged concentrically in the abrasive introduction passage 20 so as to surround the entire circumference in the outer circumferential direction centering on the injection port 11. An opening 21 of the abrasive introduction path 20 is formed (see FIG. 2).

  However, the shape and arrangement of the acceleration flow generating nozzle 10 and the abrasive introduction path 20 are not limited to the embodiment shown in FIGS. It may be formed in a cylindrical shape, and as shown in FIGS. 4 (A) and 4 (B), the injection port 11 of the acceleration flow generating nozzle 10 is formed in a slit shape, and this slit shape is formed. An opening 21 of the abrasive material introduction path 20 may be provided in parallel with the injection port 11 of the acceleration flow generating nozzle 10, and further, as shown in FIGS. 5A and 5B, this abrasive material introduction path. 20 openings 21 may be arranged on both sides centering on the injection port 11 of the acceleration flow generation nozzle 10 (see FIG. 5B), and toward the acceleration flow S generated by the acceleration flow generation nozzle 10. The acceleration flow S is provided by providing the opening 21 of the abrasive introduction path 20. As long as it can be merged abrasive against a possible various design changes are.

  The accelerating flow generation nozzle 10 and the accelerating flow generation nozzle 10 are arranged so that the injection port 11 of the accelerating flow generation nozzle 10 protrudes in the injection direction with a slight projecting length (δ 2 in FIG. 3) from the opening 21 of the abrasive introduction path 20. The arrangement of the abrasive introduction path 20 is determined.

  The protruding length δ2 at the tip of the acceleration flow generating nozzle 10 is preferably 1.0 to 3.0 mm. In the illustrated embodiment, the protruding length δ2 is set to 1.0 mm. When the injection port 11 of the acceleration flow generation nozzle 10 is arranged toward the surface of the workpiece, the abrasive is introduced with respect to the interval δ1 between the injection port 11 of the acceleration flow generation nozzle 10 and the surface of the workpiece W. The distance between the opening 21 of the path 20 and the surface of the workpiece W is increased.

  The introduction of the abrasive 30 into the abrasive introduction path 20 described above is performed, for example, by dropping the abrasive by gravity from an abrasive tank (not shown) disposed at a high position with respect to the abrasive introduction path 20. However, in this embodiment, the internal space of the above-described abrasive introduction path 20 is pressurized by the carrier fluid P2 that is a compressed gas, such as the abrasive tank of a direct pressure blasting apparatus. By communicating with a polishing material tank (not shown), the polishing material 30 transported as a mixed fluid with the transporting fluid P2 is introduced into the internal space of the polishing material introduction path 20, and the opening 21 described above is introduced. And the acceleration flow S can be merged.

  In order to enable such conveyance of the abrasive 30, in the embodiment shown in FIG. 1, the abrasive nozzle 24 is attached to the tip of an abrasive hose 25 communicating with an abrasive tank (not shown) for polishing. Along with controlling the amount of material transported, the tip of the abrasive nozzle 24 is inserted into the connecting pipe 23 communicating with the internal space of the abrasive material introduction path 20, so that the material is transferred into the abrasive material introduction path 20 together with the transport fluid P 2. The abrasive 30 can be introduced.

[Polishing method]
The accelerating flow generating nozzle 10 of the blast nozzle 1 configured as described above is communicated with a compressed gas supply source of a blast processing apparatus (not shown) as described above, and the above-described jet fluid P1 is 0.1. Introduce a compressed gas of ~ 0.7 MPa.

  Further, the abrasive material supply path of an unillustrated blasting apparatus is also communicated with the abrasive material introduction path 20 so that the abrasive material 30 can be introduced. At this time, when the abrasive 30 is transported by mixing with the above-described transport fluid P2, the pressure of the transport fluid P2 is set to be lower than the pressure of the jet fluid P1, and preferably less than two-thirds. .

  The type of the jet fluid introduced into the acceleration flow generation nozzle 10 and the type of the carrier fluid used for conveying the abrasive 30 are not particularly limited as long as they are compressed gas, and are generally used in blasting in this embodiment. Used compressed air.

  However, when the abrasive used has a particle size or material that may cause a dust fire, various compressed gases can be used depending on the processing conditions, such as using a compressed gas of an inert gas.

  As described above, the blast nozzle 1 is communicated with each of the compressed gas supply source and the abrasive supply source of the blast processing apparatus, and the injection fluid is injected from the injection port 11 of the acceleration flow generation nozzle 10 as shown in FIG. .

  The jet fluid is jetted from the jet port 11 when the jet fluid collides with the surface of the workpiece W and passes through the interval δ1 between the nozzle tip and the surface of the workpiece W. In order to generate the acceleration flow S along the surface of the workpiece W, it is adjusted to a relatively narrow interval δ1, preferably about 0.5 to 3.0 mm (in this embodiment, the interval δ1). δ1 is 1.0 mm).

  Further, in order to stably generate such acceleration flow S, the diameter φ (see FIG. 3) of the tip portion of the acceleration flow generation nozzle 10 is set to 1.4 to 2 with respect to the diameter of the injection port 11. In the present embodiment, the diameter of the injection port 11 is 3 mm, and the diameter φ of the tip portion of the acceleration flow generating nozzle 10 is 5 mm as an example.

  In this way, when the introduction of the jet fluid P1 to the acceleration flow generating nozzle 10 is started and the abrasive 30 is introduced into the abrasive introduction path 20 alone or as a mixed fluid with the carrier fluid P2, the acceleration flow generating nozzle 10 is introduced. The jet fluid P1 jetted from the jet nozzle 11 is introduced into the interval δ1 between the acceleration flow generation nozzle 10 and the surface of the workpiece W, changes its direction, and is diffused in the entire circumferential direction of the acceleration flow generation nozzle 10. Thus, the acceleration flow S flows along the surface of the workpiece W.

  Then, when passing through the gap between the opening 21 of the abrasive introduction path 20 and the surface of the workpiece, the abrasive 30 from the abrasive introduction path 20 joins the acceleration flow S and rides on the acceleration flow S. The abrasive 30 slides on the surface of the workpiece.

  As described above, the relatively high pressure injection fluid P1 of 0.1 to 0.7 MPa (0.3 MPa in the embodiment) introduced into the acceleration flow generation nozzle 10 is applied to the tip of the acceleration flow generation nozzle 10 and the workpiece. By passing a relatively narrow distance δ1 of 0.5 to 3 mm (1.0 mm in the embodiment) formed between the workpieces W, a relatively high-speed acceleration flow S is generated along the surface of the workpiece. The acceleration flow S acts like an air curtain that covers the surface of the workpiece W.

  Therefore, even when the abrasive material is introduced into the abrasive material introduction path 20 by the carrier fluid P2 that is a compressed gas, the abrasive material 30 collides with the surface of the workpiece W in the vertical direction. , It is possible to prevent the abrasive 30 from exerting a cutting force in a direction perpendicular to the surface of the workpiece W.

  In particular, when the pressure of the transport fluid P2 is set to a low pressure relative to the pressure of the jet fluid P1, and preferably, the pressure of the transport fluid P2 is set to a pressure that is less than two-thirds of the pressure of the jet fluid P1, It can suppress significantly that the abrasive 30 exhibits the cutting force of the orthogonal | vertical direction with respect to the surface of the workpiece W. FIG.

  Further, the introduction of the abrasive is performed by the carrier fluid P2 that is a compressed gas in this way, so that the carrier gas is discharged from the opening 21 of the abrasive introduction path 20 so as to press the acceleration flow S against the surface of the workpiece W. Thus, the acceleration flow S can be prevented from being separated from the surface of the workpiece W, and can be moved along the surface of the workpiece W over a longer distance.

  As a result, unlike the conventional general blasting method in which the abrasive exhibits a cutting force in a direction orthogonal to the surface of the workpiece W, in the polishing method of the present invention, the abrasive 30 is processed. By sliding along the surface of the workpiece W, a horizontal cutting force can be exerted on the surface of the workpiece W. As a result, as shown in FIG. It is possible to gradually polish and remove from the peak portion of the unevenness generated on the surface.

  Because of this cutting action, the polishing method of the present invention does not remove the surface of the workpiece in the depth direction more than necessary, and soft polishing is performed only with the energy of the compressed gas. It is possible to prevent new deep polishing scratches from being made in the polishing process.

  In addition, in the polishing method of the present invention, unlike lapping polishing, polishing polishing, and the like, no abrasive material touches the workpiece, so that extra stress is difficult to enter after polishing, preventing the occurrence of distortion, etc. Not only has the effect of being able to do this, but even when compared with the conventional general blasting method, it prevents the abrasive from colliding in the vertical direction. Can be reduced.

  Next, working test examples for various test pieces by the polishing method of the present invention will be introduced as examples.

  The blast nozzle used in the embodiment described below has the same structure as that described with reference to FIG. 1, and the diameter of the injection port 11 of the acceleration flow generating nozzle 10 is 3 mm and the diameter of the nozzle tip. (Φ) is 5 mm, the diameter of the opening 21 of the abrasive introduction passage 20 is 20 mm, and the protruding length δ2 at the tip of the acceleration flow generating nozzle 10 is 1.0 mm.

  In each of the examples, the distance δ1 between the tip of the acceleration flow generating nozzle and the surface of the workpiece W is set to 1.0 mm, and each of the examples and comparative examples has a plate having a width of 90 mm and a length of 90 mm as a test piece. And half of them (45 mm x 90 mm) were observed.

A. Processing example A-1. Contrast test with general blasting (1) Purpose of the test The polishing method of the present invention (Example 1) is applied to the surface (mirror surface) of a test piece without unevenness, and the conventional method of injecting an abrasive together with compressed gas By performing general blasting (Comparative Example 1) and observing how the surface of the test piece after processing changes, the difference in the behavior of the abrasive on the surface of the test piece can be observed with both processing methods. Check.

(2) Test conditions [Example 1]
Test piece: Soda glass (mirror surface)
Abrasive: High-purity alumina abrasive "Fuji Random WA # 220" manufactured by Fuji Seisakusho (average particle size 53-45 μm)
Supply pressure: Acceleration flow generation nozzle; 0.3 MPa (compressed air)
Abrasive supply nozzle: 0.1 MPa (compressed air) + abrasive processing time: 13 minutes (processing time for the observed 45 mm × 90 mm range: the same applies hereinafter)
[Comparative Example 1]
Test piece: Soda glass (mirror surface)
Abrasive: High purity alumina abrasive "Fuji Random WA # 600" manufactured by Fuji Seisakusho (average particle size 20.0 ± 1.5μm)
Injection method: Abrasive material is injected perpendicularly to the surface of the test piece together with compressed air of 0.4 MPa Processing time: 1 minute

(3) Test results The surface state of an untreated test piece (used in Example 1) is shown in FIGS. 8A and 8B, and the surface state of the test piece after treatment in Example 1 is shown in FIG. FIGS. 10A and 10B show the surface states of the test pieces after the processing of Comparative Example 1 in FIGS. 10A and 10B, respectively.

  The surface roughness of each test piece is shown in Table 1 below.

  Of the roughness parameters, Ra (arithmetic average roughness), Ry (maximum height), Rz (ten-point average roughness), and tp (additional length ratio) are all JIS (JISB0601- 1994) (the same shall apply hereinafter).

  RMS is “root mean square roughness”, and this value is obtained as the square root of a value obtained by squaring the deviation from the average line to the measurement curve based on the roughness curve (see FIG. 7; the same applies hereinafter).

(4) Consideration based on test results As can be seen from the comparison between FIG. 8 and FIG. 10, the surface of the test piece which was a mirror surface before the treatment [FIGS. After the treatment, it changed to an uneven surface having sharp peaks and valleys (see FIG. 10B).

  Further, in the processing method of Comparative Example 1, compared with the processing method of Example 1, an abrasive having a small particle size (and thus generally having a small effect of roughening the surface) is used. It was confirmed that the surface roughness was greatly increased in all parameters as compared with the processing method of Example 1.

  Therefore, as in Comparative Example 1, in the known blasting method in which the abrasive material collides with the surface of the test piece together with the compressed gas, the collided abrasive material cuts the surface of the test piece in the vertical (depth) direction. It can be seen that it exerts the action of

  On the other hand, when the treatment of Example 1 was performed, the surface of the untreated test piece that was a mirror surface was shaved to form irregularities, but the peaks and valleys of these irregularities were the same as those of Comparative Example 1. It can be confirmed that the shape is comparatively gentle rather than sharp as in the case (see FIG. 9B).

  Further, in Example 1, an abrasive having a larger particle diameter than that of Comparative Example 1 and, therefore, an abrasive having a large effect of roughening the surface was used. The parameter also shows that the increase in roughness is small compared to Comparative Example 1 (the difference in height of the formed irregularities is small), and the cutting force perpendicular to the surface of the test piece is exhibited. It can be seen that it is possible to greatly suppress this.

  From the above results, it can be seen that there is a clear difference in the behavior of the abrasive on the surface of the test piece in the two treatments of Example 1 and Comparative Example 1, and as described with reference to FIG. In this general blasting method, the abrasive cuts the surface of the workpiece in the depth direction by the energy at the time of collision, whereas the polishing method of the present invention (Example 1) is an abrasive. As shown in FIG. 6, it can be seen that the cutting force in the horizontal direction is exerted on the surface of the test piece by sliding along the surface of the workpiece.

  Further, due to the cutting principle in the method of the present invention (Example 1) as described above, damage caused by collision of abrasive (abrasive grains) against the surface of the workpiece as in known blasting is caused. In addition, it can be seen that it is possible to perform the work of thinly cutting the surface portion of the workpiece, which was difficult with the conventional blasting.

A-2. Surface roughness improvement test (Example 2)
(1) Purpose of the test It is confirmed that the surface roughness of the test piece can be improved (flattened) by applying the polishing method of the present invention to a glass test piece with uneven surfaces. To do.

(2) Test conditions Test piece: Soda glass (after processing according to Comparative Example 1)
Abrasive: High-purity alumina abrasive "Fuji Random WA # 1000" manufactured by Fuji Seisakusho (average particle size 11.5 ± 1.0 μm)
Supply pressure: Acceleration flow generation nozzle; 0.3 MPa (compressed air)
Abrasive supply nozzle; 0.1 MPa (compressed air) + abrasive Processing time: 13 minutes

(3) Test results The surface state of the test piece after the treatment according to Example 2 is shown in FIGS. 11A and 11B (see FIGS. 10A and 10B for the surface state before the treatment).

  The surface roughness of each test piece is shown in Table 2 below.

(4) Consideration based on test results From the above results, it was confirmed that the surface roughness of the test piece was improved (flattened) by the method of the present invention (Example 2).

  Further, as can be seen from the comparison between FIG. 10B and FIG. 11B, the surface irregularities of the test piece having sharp peaks and valleys in the untreated state (see FIG. 10B). It can be seen that after the treatment according to the method of the present invention (Example 2), the shape is changed to a gentle uneven shape with the corners removed (see FIG. 11B).

  Further, in any of the numerical values of parameters Ra, Ry, Rz and RMS indicating the surface roughness, the surface roughness of the test piece after the processing of the present invention is improved. Therefore, it is shown that the height difference in the unevenness is reduced.

  Moreover, in the roughness parameter, an increase in the numerical value of tp indicates that the cutting level of 50% has moved to the valley bottom in the original unevenness, and thus the height of the mountain has decreased with respect to the original unevenness. As described with reference to FIG. 6, the polishing by the method of the present invention exerts a horizontal cutting force by sliding the abrasive along the surface of the test piece, and the ridges in the unevenness. It can be seen that this is done by cutting in a horizontal direction.

  As described above, it was confirmed that the polishing method of the present invention is applicable to the improvement (smoothing) of the flatness of the workpiece surface, which was difficult in the conventional general blast processing. .

B. Processing example for aluminum alloy B-1. Surface roughness improvement test (Example 3, Comparative Examples 2 and 3)
(1) Purpose of the test While confirming that the surface roughness of the test piece can be improved by applying the polishing method of the present invention to the test piece having unevenness (hairline) on the surface, the same Compared with the processing state when the known blasting is performed on the test piece with the unevenness (hairline) formed, the difference in the behavior of the abrasive on the test piece surface of both processing methods is confirmed.

(2) Test conditions [Example 3]
Test piece: Hairline processed product of aluminum alloy (A5052P) Abrasive: High-purity alumina abrasive “Fuji Random WA # 1000” manufactured by Fuji Seisakusho (average particle size 11.5 ± 1.0 μm)
Supply pressure: Acceleration flow generation nozzle; 0.3 MPa (compressed air)
Abrasive supply nozzle: 0.1 MPa (compressed air) + Abrasive Treatment time: 13 minutes [Comparative Example 2]
Test piece: Hairline processed product of aluminum alloy (A5052P) Abrasive: High-purity alumina abrasive “Fuji Random WA # 1000” manufactured by Fuji Seisakusho (average particle size 11.5 ± 1.0 μm)
Injection method: Abrasive material is injected perpendicularly to the surface of the test piece together with compressed air of 0.2 MPa (distance between nozzle and test piece is 150 mm)
Processing time: 30 seconds [Comparative Example 3]
Test piece: Hairline processed product of aluminum alloy (A5052P) Abrasive: High-purity alumina abrasive “Fuji Random WA # 1000” manufactured by Fuji Seisakusho (average particle size 11.5 ± 1.0 μm)
Injection method: Abrasive material is injected perpendicularly to the surface of the test piece together with compressed air of 0.4 MPa (distance between nozzle and test piece is 150 mm)
Processing time: 30 seconds

(3) Test results The surface condition of an untreated test piece (used in Example 3) is shown in FIGS. 12 (A) and 12 (B). The test piece after treatment by the method of the present invention (Example 3) is shown in FIGS. FIGS. 13A and 13B show the surface state, and the test pieces after the conventional general blast processing (Comparative Example 2) with an injection pressure of 0.2 MPa are shown in FIGS. 15A and 15B show test pieces after being processed by a conventional general blasting process (Comparative Example 3) with an injection pressure of 0.4 MPa, respectively.

  The surface roughness of each test piece is shown in Table 3 below.

(4) Consideration based on test results From the above results, in the polishing method of the present invention (Example 3), the surface roughness was improved with respect to the untreated test piece, and the impact of abrasives like aluminum According to the method of the present invention, it was confirmed that polishing can be suitably performed on a material that can cause plastic deformation due to the above, without causing a matte finish or the like.

  Further, as can be seen from a comparison between FIG. 12 and FIG. 13, hairlines clearly appearing on the surface of the untreated test piece [concave grooves and ridges crossing the test piece in the width direction: FIG. 12 (A), ( B)] completely disappeared after the processing of the present invention (Example 3) was performed [FIGS. 13A and 13B].

  On the other hand, in the conventional general blasting, when the injection pressure is set to 0.2 MPa, the surface roughness of the test piece (for example, Ra) is processed so as not to change (deteriorate) significantly (comparative example) In 2), traces of the hairline could be clearly confirmed (see FIGS. 14A and 14B), and the surface roughness deteriorated without improvement (see Table 3).

  Further, in the conventional general blast processing, when the injection pressure is set to 0.4 MPa and the degree of processing is further increased (Comparative Example 3), the case of Comparative Example 2 as shown in FIGS. 15 (A) and 15 (B). Although the presence of the hairline is unclear compared to the above, when the shape of both sides in the length direction of the stereoscopic image shown in FIG. It can be seen that the concavo-convex shape corresponding to the top or bottom of the original hairline is maintained.

  Moreover, by increasing the degree of processing in this way, the numerical value of the roughness is greatly increased in comparison with the test piece of Comparative Example 2 as well as the untreated test piece, and the surface roughness is improved. It was confirmed that the condition was getting worse.

  From the above test results, in the conventional general blasting process, as described with reference to FIG. 18, the morphological characteristics of the original surface irregularities are maintained, and the entire surface of the test piece is deepened. As a result, when the test piece on which the hairline is formed is machined, it is possible to completely remove the hairline or traces even if the cutting amount is increased. It is thought that there was not.

  On the other hand, in the processing method of the present invention (Example 3), it is clear from the fact that the hairline generated on the surface of the untreated test piece has completely disappeared. By sliding along the surface of the workpiece, as described with reference to FIG. 6, the minimum and maximum cutting is achieved without increasing the amount of cutting in the depth direction by cutting and removing the uneven peaks. It is thought that the morphological features that the original unevenness had had disappeared efficiently.

  Due to these characteristics, the polishing method of the present invention improves the flatness, removes tool marks such as various machine parts, and causes surface roughness, which cannot be performed by the conventional general blasting method. It is considered that the present invention can be suitably applied to operations such as removing a film formed on the surface without any problems.

  The numerical value of Ra 0.133 μm, which is the surface roughness after processing in Example 3, is processed by using a fine abrasive of about 3 times (about # 3000) in the conventional general blast processing. The surface roughness is almost the same as that performed.

  In general, abrasives are more expensive as they become smaller powders, and they are difficult to handle, such as aggregation due to bonding between particles, contamination of the work environment due to scattering and floating, and risk of dust fire depending on the material. From the above, according to the method of the present invention, the same or better effect can be obtained by using an abrasive having a larger particle size compared to conventional general blasting, and hence an inexpensive and easy to handle abrasive. I understand.

B-2. Confirmation test of influence accompanying change of processing conditions (Examples 3 to 5)
(1) Purpose of the test The effect of changes in the particle size of the abrasive used and the abrasive supply pressure (pressure of the carrier fluid P2 in FIG. 1) on the processing state is confirmed.

(2) Test Method Three test pieces made of a hairline processed aluminum alloy plate (A5052P) were processed according to the method of the present invention under the conditions shown in Table 4 below.

(3) Test results The surface state of the test piece after the treatment according to Example 4 is shown in FIGS. 16A and 16B, and the surface state of the test piece after the treatment according to Example 5 is shown in FIGS. ) Respectively.

  The surface state of the untreated test piece (used in Example 3) is shown in FIGS. 12A and 12B, and the surface state of the test piece after treatment in Example 3 is shown in FIG. See (B).

  The surface roughness of each test piece is shown in Table 5 below.

(4) Consideration based on test results From the above results, it was confirmed that the hairline was removed for those processed under any of the conditions of Examples 3 to 5 (see FIGS. 13, 16, and 17). .

  When the abrasive material exhibits a cutting force in the depth direction against the surface of the test piece as in the conventional general blasting (Comparative Examples 2 and 3), the hairline can be completely removed. In view of the inability to do so, in the processing of Examples 3 to 5 where the hairline has disappeared, the abrasive is slid along the surface of the workpiece regardless of the particle size of the abrasive used. Therefore, it is considered that the cutting force in the horizontal direction can be exerted on the surface of the test piece.

  In Examples 3 and 5, the pressure of the transport fluid P2 used for transporting the abrasive is 0.1 MPa, whereas in Example 3, the pressure of the jet fluid P1 is doubled to 0.2 MPa. However, it was confirmed that cutting in the direction perpendicular to the surface of the workpiece could be suppressed even by such a pressure increase.

  The polishing method of the present invention described above is performed in place of conventional general blasting and known polishing methods, such as polishing, lapping, buffing, ultrasonic polishing, and the like using polishing paper or polishing cloth. It can be used in various fields.

  In particular, the polishing method of the present invention allows the abrasive to slide on the surface of the workpiece, thereby suppressing the generation of a cutting force in the vertical direction with respect to the surface of the workpiece, while exerting the horizontal cutting force. Therefore, it is possible to reduce the damage to the work piece as much as possible and to reduce the amount of cutting in the depth direction and to polish the surface part thinly. In particular, it is expected to be used in the following fields.

(1) Lapping pretreatment As a pretreatment for lapping, it can be used to improve the surface roughness of the workpiece. In particular, in the method of the present invention, as described above, damage to the workpiece is caused. For example, it is suitable for use in pretreatment for polishing a wafer (silicon, quartz, sapphire, etc.). Moreover, since the method of the present invention can improve the surface roughness, it can be expected that the subsequent lapping effort can be greatly reduced.

(2) Thin film removal etc. In the method of the present invention, since the abrasive slides on the surface of the workpiece, cutting near the surface is possible without increasing the amount of cutting in the depth direction. It is possible to remove the thin film without cutting the base material at a depth more than necessary for removing the formed thin film.

  In particular, even when a thin film of a different material is formed on the thin film, it can be removed in one step according to the method of the present invention. This eliminates the need for complicated work such as replacement of chemical solutions according to the conditions.

(3) Pre-formation process (surface activation) of laminated film
Furthermore, in the method of the present invention, the surface of the work piece can be peeled off very slightly with an abrasive that slides on the surface of the work piece. By performing the surface treatment of the present invention on the surface of the base material in advance, the work to remove the oxide film etc. generated on the surface and expose the active surface is performed without greatly reducing the flatness of the base material. I think that I can do it.

  Therefore, it is expected that the adhesion strength between the base material and the laminated film can be improved by performing the polishing method of the present invention as a pretreatment for forming the laminated film by sputtering or various vapor depositions.

(4) Scratching and tool mark removal As described above, according to the method of the present invention, it is possible to remove the hairline formed on the test piece. It can also be suitably used for removing scratches generated on the tool and tool marks generated as contact marks with the cutting tool.

DESCRIPTION OF SYMBOLS 1 Blast nozzle 10 Acceleration flow generation nozzle 11 Injection port 20 Abrasive material introduction path 21 Opening 23 Connection pipe 24 Abrasive material nozzle 25 Abrasive material hose 30 Abrasive material P1 Injection fluid P2 Conveyance fluid S Acceleration flow W Workpiece δ1 interval (acceleration flow (Between the tip of the generating nozzle and the surface of the workpiece)
δ2 Protrusion length (accelerated flow generation nozzle tip with respect to abrasive material introduction path opening)

Claims (11)

Injecting and injecting a compressed gas not containing an abrasive as an injection fluid into an acceleration flow generating nozzle arranged toward the surface of the workpiece, and generating an acceleration flow along the surface of the workpiece,
By introducing an abrasive into an abrasive introduction path that opens toward the surface of the workpiece at the position where the accelerated flow is generated, the abrasive is joined to the accelerated flow, and the abrasive is moved to the workpiece. A polishing method characterized by sliding along a surface.   2. The abrasive according to claim 1, wherein the abrasive is mixed with a carrier fluid which is a compressed gas having a pressure lower than that of the jet fluid introduced into the acceleration flow generation nozzle and introduced into the abrasive introduction path. Polishing method.   The polishing method according to claim 2, wherein the carrier fluid is set to a pressure equal to or less than two-thirds of the jet fluid.   4. The gap between the opening of the abrasive introduction path and the surface of the workpiece is made wider than the gap between the jet of the acceleration flow generating nozzle and the surface of the workpiece. The polishing method according to claim 1.   The distance between the jet of the acceleration flow generating nozzle and the surface of the workpiece is set to 0.5 to 3.0 mm, and the distance between the opening of the abrasive introduction path and the surface of the workpiece is accelerated. 5. The polishing method according to claim 4, wherein the polishing method is formed to be 1.0 to 3.0 mm wider than a distance between the jet port of the flow generating nozzle and the surface of the workpiece. An acceleration flow generating nozzle for injecting a compressed gas not containing an abrasive supplied from a compressed gas supply source toward the surface of the workpiece and generating an acceleration flow along the surface of the workpiece; ,
A nozzle structure for a blasting apparatus, comprising an abrasive introduction path that opens toward the surface of the workpiece at a position where the acceleration flow is generated and into which an abrasive from an abrasive supply source is introduced .   The nozzle structure in the blast processing apparatus according to claim 6, wherein the abrasive introduction path communicates with an abrasive supply source that supplies the abrasive as a mixed fluid with a carrier fluid that is a compressed gas.   The nozzle structure of the blast processing apparatus according to claim 6 or 7, wherein an end portion on the injection port side of the acceleration flow generating nozzle is disposed in the abrasive introduction path.   The blast nozzle according to claim 6 or 7, wherein the blast nozzle of the acceleration flow generating nozzle is formed in a slit shape, and the opening of the abrasive introduction path is arranged in parallel to the blast port.   The blast nozzle according to claim 9, wherein openings for the abrasive introduction path are arranged on both sides of the injection port of the acceleration flow generating nozzle.   The blast nozzle according to any one of claims 6 to 10, wherein an injection port of the acceleration flow generation nozzle is projected in an injection direction of 1.0 to 3.0 mm with respect to an opening of the abrasive material introduction path. .