JP4471197B2 - Polishing method that does not require processing pressure control - Google Patents

Description

  The present invention relates to a polishing method that does not require processing pressure control and an abrasive used therefor.

  Polishing using lapping called lapping or polishing using polishing pad in conventional metal material, etc., requires lapping or polishing pad, so the surface of metal material etc. to be polished Wraps and polishing pads must be prepared according to the shape. However, since it is impossible to cope with all shapes, only a polishing apparatus having a limited shape of the polishing surface can be produced, and it is necessary to rely on human hands.

  The present inventor has previously filed a magnetic compound fluid (MCF: Magnetic Compound Fluid) in which abrasive grains and magnetite are mixed with a magnetic fluid. However, there is a problem that the roughness of the polishing surface is inferior to that in the case of using a pad, or that the polishing liquid cannot be retained on the work by the attractive force of the magnetic field (see, for example, Patent Document 1).

JP 2002-170791 A

As described above, the conventional polishing method requires a lapping and polishing pad, and even when polishing using a magnetic fluid mixture, if the pad is not used, the roughness of the polishing surface will be inferior or the magnetic field will be attracted. There was a problem that the polishing liquid could not be retained on the workpiece. Therefore, the present invention makes it possible to mix α-cellulose, fix abrasive grains to cellulose fibers, and increase the viscosity of the polishing liquid so that the polishing liquid can be sufficiently retained on the workpiece by a magnetic field attraction. Thus, an object of the present invention is to provide a polishing method which can be applied to an arbitrary curved polishing surface and which does not require a processing pressure control, so that a better polishing surface can be obtained than when a pad is used.

In order to achieve the above object, a polishing method according to claim 1 of the present invention that does not require machining pressure control includes an upper magnetic pole iron core in an upper electromagnet coil, and an electromagnet that rotates in a direction opposite to the upper magnetic pole iron core. and the lower magnetic pole iron core of the coil, consists of a the installed sample holder on the lower magnetic pole iron core, in a dispersion medium such as water or kerosene kinematic viscosity of 0.01 to 10 mm ₂ / s, the particle diameter 1 10 nm spherical magnetite (Fe ₃ O ₄ ) particles using water or kerosene as the dispersion medium are uniformly dispersed in the fluid in which 10 to 70 wt% of 10 μm ferromagnetic particles are dispersed. A magnetic fluid is formed by mixing non-magnetic abrasive particles having a particle diameter of 0.01 to 10 μm with a composite fluid in which 20 to 50 wt% of the dispersed fluid is mixed, and 8 α-cellulose is added to the magnetic polishing fluid. ~ 50wt% mixed abrasive on top The magnetic pole is supplied between the magnetic pole iron core and the sample to be polished on the sample holder, and the magnetic abrasive is applied with a magnetic field constantly or variably in time by an electromagnet, while the upper magnetic pole iron core and the lower magnetic pole are applied. The sample was polished by rotating the iron core.

  As a result, when a magnetic field is applied, a cluster composed of a large number of magnetite and iron powder is formed, and the abrasive grains in the cluster are pressed against the polishing surface for polishing, or the clusters are pressed against the polishing surface for polishing. Since it is possible to polish polishing with a polishing device with a limited polishing surface shape using a lapping or polishing pad, or polishing that is not possible with manual polishing, without the need to control the processing pressure, it changes. It can be used as a processing method for fine precision parts because it can polish polished surfaces with abundant shapes precisely and efficiently.

As described above, according to the polishing method of the present invention, polishing using a lapping device having a limited polishing surface shape using a lapping or polishing pad in conventional metal materials or the like, which is impossible by manual polishing, is impossible. Can be polished without the need for controlling the processing pressure, and the polished surface having a variety of shapes can be polished precisely and efficiently, so that it can be used as a processing method for fine precision parts. As a result, costs and labor in lapping and polishing can be greatly reduced, which is very useful from an industrial viewpoint.

The present invention electrically insulates a fluid in which 10 to 70 wt% of ferromagnetic particles having a particle diameter of 1 to 10 μm are dispersed in a dispersion medium such as water or kerosene having a kinematic viscosity of about 0.01 to 10 mm ₂ / s. Particles having a particle diameter of 0.01 to 10 μm are mixed with a composite fluid in which 20 to 50 wt% of a fluid in which 10 nm spherical magnetite (Fe ₃ O ₄ ) particles using water or kerosene as a dispersion medium is uniformly dispersed in the dispersion medium is mixed. of a mixture of abrasive particles of magnetic forms a magnetic polishing liquid, to the magnetic polishing solution was prepared environmentally friendly α (alpha) over cellulose mix 8 50 wt% new polishing solution. Further, in lapping without wrapping or polishing without using a polisher pad, the polishing sample is polished using this magnetic polishing liquid in a magnetic field.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a polishing apparatus to which a polishing method that does not require processing pressure control according to the present invention is applied. In the figure, 1 is a polishing sample, 2 is a lower magnetic pole iron core having a sample holder (not shown) on which the polishing sample 1 is installed, 3 is an upper magnetic pole iron core, and 4 is an abrasive comprising the magnetic polishing liquid of the present invention. 5 is an electromagnet that excites the lower magnetic pole core 2, 6 is a coupling, 7 is an AC servo motor, 8 is a speedometer, 9 is a position adjuster, 10 is an electromagnet that excites the upper magnetic pole iron core 3, and 11 is a cup. A ring, 12 is an AC servo motor, 13 is a speedometer, 14 is an electromagnet power supply, 15 and 16 are bearing bearings fixed to the outer frame, 17 is a cooling water tank, and 18 is a pump for supplying cooling water to the electromagnet. Reference numeral 19 denotes a polisher pad, which is not necessary for the novel polishing method of the present invention, but is attached to the upper magnetic pole iron core 3 when compared with the embodiment of the present invention.

  FIG. 2 shows an enlarged view of the positional relationship between the polishing sample 2 and the lower magnetic pole iron core 2 that fixes the polishing sample 1, and the upper magnetic pole iron core 3 and the abrasive 4. FIG. 2A is a state diagram in which the polishing pad 19 is attached to the upper-side magnetic pole iron core 3. FIG. 5B is a polishing state diagram of the present invention that does not require the polishing pad 19. Here, x is the distance between the upper magnetic pole core 3 and the polished sample 1.

  The polishing operation in the polishing apparatus of FIG. 1 is as follows. The lower magnetic pole iron core 2 and the upper magnetic pole iron core 3 are excited by respective electromagnets (coils) 5 and 10 connected to a power source 14. The polishing sample 1 is fixed on the lower magnetic pole iron core 2, and an abrasive 4 made of a newly developed magnetic polishing liquid is interposed between the lower magnetic pole iron core 3 and the upper magnetic pole iron core 3.

  The lower magnetic pole iron core 2 is driven and rotated through a coupling 6 by an AC servo motor 7. Similarly, the upper magnetic pole iron core 3 is driven and rotated in the direction opposite to the rotation direction of the lower magnetic pole iron core 2 through the coupling 11 by the AC servo motor 10. The AC servomotors 7 and 10 have their rotational speeds detected by the respective speedometers 8 and 13, and are controlled to a predetermined rotational speed by a speed control device (not shown).

  A magnetic field is applied to the magnetic polishing liquid by applying a stationary or fluctuating magnetic field with time using an electromagnet. Further, the electromagnets 5 and 10 are supplied with cooling water from the cooling water tank 17 by the pump 18 to prevent overheating. Then, the position adjuster 9 aligns the distance between the upper and lower magnetic pole iron cores 2 and 3 including the polishing sample 1.

Mixing a fluid in which ferromagnetic particles are separated in a dispersion medium such as water or kerosene with a fluid in which magnetite fine particles (Fe ₃ O ₄ ) with water or kerosene as the dispersion medium are dispersed uniformly. The composite fluid is mixed with non-magnetic abrasive grains (Al ₂ O ₃ , Cr ₂ O ₃ etc.) and α-cellulose.

More specifically, for a fluid in which 10 to 70 wt% of ferromagnetic particles having a particle diameter of 1 to 10 μm are dispersed in a dispersion medium such as water or kerosene having a kinematic viscosity of about 0.01 to 10 mm ₂ / s, A composite fluid obtained by mixing 20 to 50 wt% of a fluid in which 10 nm spherical magnetite (Fe ₃ O ₄ ) particles having electrically insulating water or kerosene as a dispersion medium is uniformly dispersed in the dispersion medium is mixed with a particle diameter of 0.01. by mixing the abrasive particles of non-magnetic ~10μm forms a magnetic polishing liquid, to the magnetic grinding fluid, constituted by mixing α cellulose 8 50 wt%.

The polishing mechanism using the novel magnetic polishing liquid of the present invention is shown in FIG. First, when a magnetic field is applied, clusters composed of a large number of magnetites (Fe ₃ O ₄ ) and iron powder (Fe) are formed. At this time, as shown in FIG (A), the case where the abrasive grains (Al ₂ O ₃₎ is being included in a cluster, as shown in FIG. (B), the abrasive grains on the outside of the cluster (Al ₂ O ₃ ) May exist. In the aspect of FIG. 3A, the inclusion of abrasive grains (Al ₂ O ₃ ) in the cluster was observed by SEM and confirmed by X-ray analysis as shown in FIG.

  In the case of FIG. 3A, the abrasive grains in the cluster are pressed against the polishing surface and polished. In the case of FIG. 3B, the abrasive is pressed against the polishing surface by the cluster and polished. By applying a steady magnetic field, the magnetic clusters are aligned along the magnetic field lines of the applied magnetic field, and are held by the magnetic force, so that the abrasive grains can hit the polishing surface appropriately and be polished. Further, by applying a variable magnetic field, the magnetic cluster rotates and swings, so that the abrasive grains can hit the polishing surface appropriately and can be polished. Since the cluster acts in this way, polishing is performed without controlling the processing pressure without pressing the surface of the sample to be polished by applying processing pressure, as in the polishing method using a polishing pad or lap. Can do.

In order to demonstrate the polishing effect of the present invention, the magnetic polishing liquid (a) having the specifications shown in the table of FIG. 5 and added with α-cellulose, which is the magnetic polishing agent of the present invention, is a comparative magnetic polishing liquid. Two types of magnetic polishing liquid (b) to which α-cellulose was not added were prepared.
The dispersion medium 1 (magnetic fluid) in the magnetic polishing liquid (a) and the magnetic polishing liquid (b) usually has a specific gravity of about 1.3. This is well known in the art. Therefore, when calculated with reference to FIG. 5, the weight of the dispersion medium 1 (magnetic fluid) is 15 ml × 1.3 = 19.5 g. Here, since the dispersion medium 1 is composed of magnetite and kerosene, and the concentration is 50 wt% as shown in FIG. 5, it becomes 9.75 g of magnetite and 9.75 g of kerosene.
Since the total weight of the magnetic polishing liquid (a) is 53.9 g and the total weight of the magnetic polishing liquid (b) is 49.5 g, the blending ratio (weight) of each magnetic polishing liquid is next determined.
The blending ratio of the magnetic polishing liquid (a) is
Since the dispersion medium 1 is 19.5 g, 36.1 wt% and the dispersion medium 2 is 12 g, 22.2 wt% (Here, since the dispersion medium 1 also contains kerosene, the total amount of kerosene The total amount of kerosene in the magnetic fluid is 21.75 g, but the dispersion medium 2 is treated as a unique value of 12 g.) Since the dispersion particle 1 (iron powder) is 15 g, the blending ratio (weight) is 27. Since 8 wt% and dispersed particles 2 (abrasive grains) are 3 g, 5.6 wt% and additive (α cellulose) are 4.49 g, so that 8.3 wt%.
The blending ratio of the magnetic polishing liquid (b) is as follows:
Since the dispersion medium 1 is x19.5 g, 39.4 wt%, and the dispersion medium 2 is 12 g, so 24.2 wt% (here, since the dispersion medium 1 also contains kerosene, the total amount of kerosene The total amount of kerosene in the magnetic fluid is 21.75 g, but the dispersion medium 2 is treated as a unique value of 12 g.) Since the dispersion particle 1 (iron powder) is 15 g, the blending ratio (weight) is 30. 3 wt% and dispersed particles 2 (abrasive grains) are 3 g, so that it is 6.1 wt%.

The magnetic polishing liquid (b) has a kinematic viscosity of 0 for a fluid in which ferromagnetic particles (Fe) having an average particle diameter of 1.2 μm are dispersed in a kerosene dispersion medium having a kinematic viscosity of about 0.03 mm ₂ / s. A non-magnetic particle having a particle diameter of 3 μm is mixed with a composite fluid in which a fluid in which 10 nm spherical magnetite (Fe ₃ O ₄ ) particles having kerosene of about 0.05 mm ₂ / s as a dispersion medium are uniformly dispersed in the dispersion medium is mixed to 50 wt%. There is a magnetic polishing liquid formed by mixing abrasive grains (Al ₂ O ₃ ). In contrast, magnetic polishing liquid is a polishing agent of the present invention (a) is a magnetic polishing liquid (b) of the above components, a polishing agent comprising mixing 8 50 wt% of α cellulose as an additive material. Addition of α-cellulose has the effect of increasing the viscosity and holding the abrasive grains.

  Using the magnetic polishing liquid (a) and the magnetic polishing liquid (b) formed in this way, polishing conditions having the specifications shown in the table of FIG. 6, that is, lower magnetic pole core 2 is 300 rpm, The upper magnetic pole core 3 is rotated in the opposite direction at a rotational speed of 800 rpm, the distance between the upper magnetic pole iron core 3 and the polishing sample 1 is 0.1 mm, and the magnetic field strength is 300 and 1800 under the polishing conditions of 0 to 90 minutes. Two tests of Gauss were performed.

  As a result, the test result at a magnetic field strength of 300 gauss was as shown in FIG. 7, and the test result at a magnetic field strength of 1800 gauss was as shown in FIG. Further, in order to compare with the polishing effect by the conventional lapping, lapping in which a lapping (polishing pad) was installed on the lower surface of the rotating upper magnetic pole iron core 3 was also performed.

  In FIG. 7 and FIG. 8, it is indicated that “polishing with pad”, “polishing without pad”, and “polishing without pad, additive-containing magnetic polishing liquid” were performed. Show each. Here, in the display of the surface roughness, Ra is the arithmetic average roughness, Ry indicates the maximum roughness, and usually Ry × 1/8 has a relationship of approximately Ra.

  As is clear from this result, whether the magnetic polishing solution containing α-cellulose as an additive without using a polishing pad is used, whether with a polishing pad or α-cellulose. The polishing effect was greater than the polishing using the magnetic polishing liquid not containing, and the polishing time could be shortened.

  In the present invention, polishing using a polishing apparatus having a limited polishing surface shape using a lapping or polishing pad or a polishing that cannot be performed manually is performed without using a processing pressure control. Therefore, the polished surface having various shapes can be polished precisely and efficiently, so that it can be used as a processing method for fine precision parts.

1 is a configuration diagram of a polishing apparatus to which a polishing method that does not require processing pressure control according to the present invention is applied. FIG. 4 is an enlarged view of the relationship between the polishing sample of the present invention, a lower magnetic pole iron core, and an upper magnetic pole iron core 3. FIG. 3 is a mechanism diagram of polishing with a magnetic polishing liquid. The observation figure by the SEM of the aspect of magnetic polishing liquid. The specification table | surface which shows the component of the magnetic polishing liquid for experiment. Specification table showing conditions for conducting polishing experiments. Test results at a magnetic field strength of 300 gauss. Test results at a magnetic field strength of 1800 gauss.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polishing sample 2 Lower magnetic pole iron core 3 Upper magnetic pole iron core 4 Abrasive agent 5,10 Electromagnet 6,11 Coupling 7,12 AC servomotor 8,13 Speedometer 9 Position adjuster 14 Electromagnet power supply 15,16 Bearing bearing 17 Cooling water tank 18 Pump 19 Polisher pad

Claims (1)

The upper magnetic pole iron core in the upper electromagnet coil, the lower magnetic pole iron core in the electromagnet coil rotating in the direction opposite to the upper magnetic pole iron core, and the sample holder installed on the lower magnetic pole iron core, Water or kerosene having electrical insulation properties with respect to a fluid in which 10 to 70 wt% of ferromagnetic particles having a particle diameter of 1 to 10 μm are dispersed in a dispersion medium such as water or kerosene having a viscosity of 0.01 to 10 mm ₂ / s. Non-magnetic abrasive grains having a particle diameter of 0.01 to 10 μm in a composite fluid obtained by mixing 20 to 50 wt% of a fluid in which 10 nm spherical magnetite (Fe ₃ O ₄ ) particles uniformly dispersed in a dispersion medium are mixed in a dispersion medium. by mixing the particles to form a magnetic polishing liquid during relative magnetic polishing liquid, the polishing agent comprising a mixture of α cellulose 8 50 wt%, the sample to be polished on the upper magnetic pole iron core and the sample holder The magnetic abrasive is applied to the electromagnet A polishing method that does not require processing pressure control, wherein the sample is polished by rotating the upper magnetic pole iron core and the lower magnetic pole iron core while applying a magnetic field more regularly or variably in time.

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