JP2020108907A - Dry barrel polishing method - Google Patents

Abstract

To provide a dry barrel polishing method that can perform polishing while adsorbing and removing dust produced by barrel polishing.SOLUTION: In the dry barrel polishing method, a first polishing medium M1 having high polishing force and a second polishing medium M2 having high dust adsorption power are used in a mixed manner as a polishing medium for use in polishing of a workpiece W, to progress polishing performed by the first polishing medium M1 while adsorbing dust to the second polishing medium M2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a dry barrel polishing method performed for deburring a workpiece, polishing a surface, and the like.

In dry barrel polishing, the work piece, the polishing media, and, if necessary, the polishing aid, are charged into the barrel tank, and a constant force such as rotation and vibration is applied to the barrel tank to load the charged material. The mass formed by is made to flow. As a result, the polishing medium collides with or scratches the workpiece, and the workpiece is polished.

In the conventional dry barrel polishing method, if the barrel polishing is continuously performed in a state where the dust is mixed in the mass, the dust may adhere to the work piece and may be fixed as dirt. This stain becomes a problem especially in barrel polishing for the purpose of gloss finish.

The polishing media is a type in which abrasive grains are bonded with a vitrified binder (Vitrified polishing media), a type in which abrasive grains are bonded with resin (resin-based polishing media), and a type composed of resin material (plastic polishing) Media) A type composed of metal (metal-based polishing media), a type composed of crushed products such as plant-based seeds (plant-based media), and a type in which a plant-based media is coated with a fine powder abrasive with oil as a medium ( Organic polishing media) is used.

For example, when a polishing medium having a non-smooth surface such as a sintered surface is used like a vitrified polishing medium, once dust adheres to the non-smooth surface, it is difficult to remove it. As a result, the polishing medium rubs against the work piece while dust is carried on the surface thereof, which may cause stains.

Further, Patent Document 1 discloses a dry barrel polishing method that uses a mixture of an organic polishing medium and a plastic polishing medium, but this method has the following problems.
(1) The object to be processed after polishing is attached with oil or fat of the organic polishing medium or is in a wet state. Therefore, cleaning with alcohol or the like is required after barrel polishing.
(2) Since both the organic polishing media and the ceramic polishing media have weak polishing power, they cannot be sufficiently polished depending on the material of the workpiece and the surface condition before barrel polishing.
(3) Since the organic polishing medium is extremely soft, it acts as a so-called cushioning material, and as a result, it hinders polishing by the plastic polishing medium.

Japanese Patent Laid-Open No. 5-138525

Therefore, an object of the present invention is to provide a dry barrel polishing method capable of performing favorable polishing processing while adsorbing and removing dust generated by barrel polishing.

In order to achieve the above-mentioned object, in the invention according to claim 1, as a polishing medium used for polishing a workpiece, a non-smooth surface to which dust generated by the polishing processing can adhere is mainly used. A technique of mixing and using a first polishing medium for polishing and a second polishing medium having a smaller polishing force than the first polishing medium and a high suction force of dust generated by polishing. Use the means.

According to a second aspect of the present invention, in the dry barrel polishing method according to the first aspect, the first polishing medium is a vitrified polishing medium.

According to a third aspect of the present invention, in the dry barrel polishing method according to the first or second aspect, the first polishing medium has a shape having no protrusion on the outer surface. Use means.

According to the invention described in claim 4, in the dry barrel polishing method described in claim 3, the technical means that the first polishing medium is spherical is used.

According to a fifth aspect of the present invention, in the dry barrel polishing method according to any one of the first to fourth aspects, the second polishing medium is made of a softer material than the first polishing medium. The technical means of becoming is used.

In a sixth aspect of the invention, in the dry barrel polishing method of the fifth aspect, the second polishing medium is made of a resin material, which is a technical means.

According to the first aspect of the present invention, by mixing and using the first polishing medium having a high polishing force and the second polishing medium having a high dust suction force, the second polishing medium causes dust to be generated. It is possible to progress the polishing with the first polishing medium while adsorbing the. As a result, when the polishing medium M scrapes the workpiece M, it is possible to prevent dust from rubbing on the workpiece and adhering as dirt. Further, since it is possible to suppress the adhesion of dust to the first polishing media, it is possible to prevent the polishing power of the first polishing media from decreasing.

As in the second aspect of the invention, it is preferable to use a vitrified polishing medium as the first polishing medium because the polishing force is high.

As in the invention described in claim 3, by using the first polishing medium as a polishing medium having a shape having no protruding portion on the outer surface, it is possible to polish the polishing force while suppressing the generation of dust. It can be of any suitable strength.

When a spherical polishing medium is used as the first polishing medium as in the invention described in claim 4, it is difficult to make a processing mark on the workpiece, and therefore it can be suitably used for the purpose of gloss finish. ..

As in the invention described in claim 5, it is preferable to use, as the second polishing medium, a polishing medium made of a material softer than that of the first polishing medium, because the dust suction force is high.

As in the invention described in claim 6, it is preferable to use a polishing medium made of a resin material as the second polishing medium because the dust suction force is higher.

It is a schematic diagram which shows an example of the barrel polishing apparatus which performs dry barrel polishing using the polishing media of this invention. 1(A) is a partial cross-sectional plan view seen from the side, and FIG. 1(B) is a partial cross-sectional plan view seen from the front. It is a flowchart which shows the process of a dry barrel polishing method.

The dry barrel polishing method of the present invention will be described with reference to the drawings. In this embodiment, dry barrel polishing using the vibrating barrel polishing apparatus shown in FIG. 1 is illustrated.

The vibrating barrel polishing apparatus 1 is configured as follows.

The vibrating barrel polishing apparatus 1 includes a polishing tank 10 having a U-shaped cross section with an open top, and is installed on a pedestal 12 via a spring 11.

The polishing tank 10 is provided with a bearing 13 at its lower part, and a rotating shaft 15 to which a counterweight 14 is fixed is rotatably fixed via the bearing 13. The rotating shaft 15 is connected to a motor 17 via a coupler 16 that transmits rotation.

Next, a dry barrel polishing method for the workpiece W will be described. FIG. 2 shows the barrel polishing process.

<S01: Mass input process>
In order to perform the vibrating barrel polishing of the workpiece W by the vibrating barrel polishing apparatus 1, first, the workpiece W forming a mass and a predetermined amount of polishing media M are loaded into the polishing tank 10. If necessary, a polishing aid can be used.

In the present embodiment, as the polishing medium M, a first polishing medium M1 mainly for polishing a workpiece, and a polishing force smaller than that of the first polishing medium M1 and having a suction force of dust generated by the polishing process. And a second polishing medium M2 having a high value are mixed and used.

As the polishing media M, various shapes such as a column shape, a spherical shape, and a pyramid shape having a diameter of several millimeters to several tens of millimeters can be used according to the purpose of polishing.

As the first polishing medium M1, it is possible to use a vitrified polishing medium composed of a sintered body obtained by sintering abrasive grains with a vitrified binder. For example, a vitrified polishing medium in which abrasive grains made of alumina are sintered with alumina fine powder as a binder can be used. Since the vitrified polishing media have high polishing power, they can be preferably used.

Further, since the vitrified polishing medium has high strength and is not easily crushed, the amount of dust generated from the first polishing medium M1 can be reduced by using the vitrified polishing medium as the first polishing medium M1. Here, since the surface of the vitrified polishing medium is a non-smooth surface, dust is likely to adhere to it. If dust adheres to the surface, the polishing power may decrease.

The first polishing medium M1 has a shape having no protruding portion on the outer surface, and is formed, for example, in a spherical shape. By using the first polishing medium M1 as a polishing medium having a shape having no protruding portion on the outer surface, it is possible to make the polishing force have an appropriate strength capable of polishing while suppressing generation of dust. In particular, for the purpose of gloss finish, it is preferable to use a spherical polishing media because the surface of the workpiece W is less likely to have processing marks. Here, the "protruding portion" refers to a portion protruding outward from the outer surface, and does not refer to a corner portion of a columnar polishing medium or the like.

Here, since the surface of the vitrified polishing medium is a non-smooth surface, dust is likely to adhere to it. If barrel polishing is continued while dust is adhering to the surface, the dust adheres to the surface of the work W because the material W rubs against the work W while carrying dust on the surface. Further, since it is difficult to remove dust adhering to the surface to be smoothed, the polishing force may decrease as the dust adheres so as to cover the entire surface to be smoothed. Therefore, it is preferable to perform barrel polishing by mixing the second polishing media M2 having the ability to adsorb dust. Since the second polishing medium M2 adsorbs the dust, it is possible to prevent the dust from adhering to the first polishing medium M1. Therefore, it is possible to fix the dirt on the workpiece W resulting from the polishing by the first polishing medium M1. In addition, it is possible to prevent the polishing power of the first polishing media M1 from decreasing due to clogging or the like.

The second polishing medium M2 can absorb dust by using a polishing medium made of a softer material than the first polishing medium M1. Since the second polishing medium M2 is soft, if dust is pressed or rubbed against the second polishing medium M2, the very surface of the second polishing medium M2 is deformed according to the shape of the dust and the dust is generated. Can be adsorbed. However, when the second polishing medium M2 is excessively soft, the second polishing medium M2 acts as a cushioning material, which hinders polishing by the first polishing medium M1. Therefore, it is preferable that the second polishing medium M2 itself has a polishing ability.

Examples of the second polishing medium M2 that has both the ability to adsorb dust and the ability to polish itself include a polishing medium made of a resin material. By using this polishing medium, it is possible to prevent the workpiece W from being damaged by the second polishing medium M2. Further, since the workpiece W can be barrel-polished without being wet, it can be particularly well-polished in the dry barrel polishing.

Here, for example, nylon can be used as the resin forming the second polishing medium M2. Nylon has the ability to adsorb dust, is softer than the first polishing medium M1, and has an appropriate hardness that does not hinder the polishing by the first polishing medium M1. You can

Here, the second polishing medium M2 may contain abrasive grains in a range that does not affect the dust adsorption ability, and the abrasive grains may be exposed on the surface to impart a polishing force. Thereby, the polishing efficiency can be improved.

<S02: Barrel polishing step>
Then, the vibration barrel polishing apparatus 1 is operated. When the motor 17 is driven, the counterweight 14 rotates, and the polishing tank 10 vibrates while drawing a substantially circular orbit according to the rotation of the counterweight 14.

The mass of the workpiece W and the polishing medium M flows due to the vibration of the polishing tank 10, and the polishing medium M repeatedly collides with or scratches the workpiece W, so that mainly the first polishing medium M1. By the action, barrel polishing of the workpiece W is performed.

At this time, dust such as polishing powder originating from the workpiece W and/or the first polishing media M1 is generated.

Since the second polishing medium M2 has a strong dust adsorption force, the generated dust is adsorbed before being firmly attached to the workpiece W and the first polishing medium M1, and is removed from the system.

As described above, the first polishing media M1 having a large polishing power and the second polishing media M2 having a high dust suction power are mixed and used, and the dust is absorbed by the second polishing media M2. The polishing can be advanced by the first polishing media M1. At this time, the second polishing medium M2 to which the dust is attached also rubs against the workpiece W, but before the dirt derived from the rubbing of the second polishing medium M2 is fixed, the first polishing Since the polishing is performed with the medium M1, it is possible to prevent the contamination of the workpiece W from being fixed.

The mixing ratio of the first polishing medium M1 and the second polishing medium M2 can be appropriately set according to the polishing purpose. Here, when the amount of the second polishing media M2 is increased, the polishing efficiency is increased and the polishing time is shortened. However, if the amount is increased too much, the polishing force tends to decrease.

Further, when the particle diameter of the second polishing medium M2 is smaller than the particle diameter of the first polishing media M1, the second polishing media M2 is more likely to hit the surface of the workpiece W and dust is once covered. The dust can be effectively removed even when it adheres to the workpiece W.

<S03: Process of collecting work piece>

After a lapse of a predetermined time, the operation of the motor 17 is stopped, the workpiece W is collected, washed by air blow or the like, and a series of barrel polishing is completed.

(Example of change)
In the present embodiment, a dry vibration barrel polishing apparatus is used as the barrel polishing apparatus, but the barrel polishing apparatus is not limited to this, and for example, a known barrel polishing apparatus such as a rotary barrel polishing apparatus, a centrifugal barrel polishing apparatus, or a fluidized barrel polishing apparatus. Can be adopted.

(Effects of the embodiment)
According to the dry barrel polishing method of the present invention, the second polishing media M1 having a large polishing power and the second polishing media M2 having a high dust suction power are mixed to be used. While the dust is adsorbed by M2, the polishing can be advanced by the first polishing media M1. As a result, it is possible to prevent the stains on the workpiece W from being fixed due to the dust generated by barrel polishing. Further, since the adhesion of dust to the first polishing media M1 can be suppressed, it is possible to prevent the polishing power of the first polishing media M1 from decreasing.

The effects of the present invention were confirmed by the following examples.

A 50 mm×75 mm×30 mm plate-shaped sample made of stainless steel (SUS304) was used as a workpiece, and deburring was performed by a dry barrel polishing method with a vibrating barrel polishing machine PVF-70D (manufactured by Shinto Kogyo Co., Ltd.). ..

The polishing media used for the test are shown below.

First polishing medium: A vitrified polishing medium whose abrasive grains are alumina. φ6 mm spherical shape.
-Second polishing media: Nylon resin plastic polishing media. A triangular prism with a side of 3 mm and a height of 3 mm.

The mixing ratio (volume ratio) of each polishing medium is as follows.

-Example 1
First polishing medium: Second polishing medium=3:1
-Example 2
First polishing medium: Second polishing medium=1:1
-Comparative example 1
First polishing medium: Second polishing medium=1:0

The stains on the surface of the workpiece were visually evaluated for the condition of deburring, and visually evaluated at the time when deburring was completed.

In Example 1, deburring was completed in 4 hours, and no stain was found on the surface of the work piece. In Example 2, deburring was completed in 2 hours, and no stain was found on the surface of the work piece. Further, in Example 2 in which the amount of the second polishing medium was large, the polishing time was shorter and the polishing efficiency was higher. In the combination of the polishing media of this example, the mixing ratio of the first polishing media and the second polishing media (first polishing media)/(second polishing media) was 0. 5 to 1. More preferably, it is 5.

On the other hand, when barrel polishing was performed for 4 hours in Comparative Example 1, stains (cloudiness) were recognized on the surface of the work piece. The surface roughness Ra after barrel polishing (specified in JIS B0601:2001) was the same as in Examples 1 and 2, so this dust was generated by barrel polishing and adhered to the workpiece during barrel polishing. It is thought that it was caused as a result.

From the above, it was confirmed that the polishing medium of the present invention has a sufficient polishing force and can prevent the surface of the workpiece from being soiled.

1... Vibration barrel polishing apparatus 10... Polishing tank 11... Spring 12... Pedestal 13... Bearing 14... Counterweight 15... Rotating shaft 16... Coupler 17... Motor M... Polishing media M1... First polishing media M2... Second polishing Media W... Workpiece

Claims (6)

As a polishing media used to polish the work piece,
A first polishing medium having a non-smooth surface to which dust generated by the polishing process can adhere, and which is mainly used for polishing the workpiece;
A dry barrel polishing method comprising: mixing a second polishing medium having a smaller polishing force than the first polishing medium and having a higher suction force of dust generated by the polishing process. The dry barrel polishing method according to claim 1, wherein the first polishing medium is a vitrified polishing medium. The dry barrel polishing method according to claim 1 or 2, wherein the first polishing medium has a shape having no protrusion on the outer surface. The dry barrel polishing method according to claim 3, wherein the first polishing medium has a spherical shape. The dry barrel polishing method according to any one of claims 1 to 4, wherein the second polishing medium is made of a material softer than that of the first polishing medium. The dry barrel polishing method according to claim 5, wherein the second polishing medium is made of a resin material.

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