WO2023162930A1

WO2023162930A1 - Barrel polishing method, and cushioning material

Info

Publication number: WO2023162930A1
Application number: PCT/JP2023/006043
Authority: WO
Inventors: 光厳徳永
Original assignee: 株式会社チップトン
Priority date: 2022-02-28
Filing date: 2023-02-20
Publication date: 2023-08-31
Also published as: JP2023125191A

Abstract

The objective of the present invention is to reduce wear of polishing stones without causing a deterioration in the polishing power of the polishing stones themselves or increasing the cost.　This barrel polishing method is a method for polishing a workpiece (11) by means of polishing stones (12), by introducing the workpiece (11), the polishing stones (12), water (13), and a cushioning material (14) into a barrel tank (10), wherein a median diameter (D50) of the cushioning material (14) is 1.2 μm to 2000 μm, and the amount of cushioning material (14) introduced is 2 wt% to 30 wt% with respect to the water (13). Since the cushioning material (14) exhibits a cushioning effect when the workpiece (11) and the polishing stones (12) collide, and when the polishing stones (12) collide with one another, the polishing stones (12) are less liable to wear. Since there is no need to adjust the composition of the polishing stones (12) or to make significant process changes, the cost does not increase. Wear of the polishing stones (12) can therefore be reduced without increasing the cost.

Description

Barrel polishing method and cushioning material

The present invention relates to a barrel polishing method and a cushioning material.

Patent Document 1 discloses a barrel polishing method in which a workpiece and polishing stones are charged into a barrel tank and the workpiece is polished. In barrel polishing, by imparting rotational motion or vibration to a barrel tank, a relative motion difference is generated between the work and the polishing stone, and the work is polished with the polishing stone. By polishing with a polishing stone, it is possible to perform desired finishing processes such as chamfering, deburring, base treatment, and gloss improvement.

JP 2003-225854 A

The more the polishing stone polishes the workpiece, the more it wears itself out. As the wear of the polishing stone progresses, the weight of the polishing stone decreases and the pressing force against the work decreases, resulting in a decrease in the polishing force. In addition, since the wastewater after polishing contains abrasion powder of the polishing stone, it is necessary to treat the wastewater with chemicals and filters for environmental conservation. and the number of filter replacements will increase. Furthermore, if the wear powder of the polishing stone adheres to the workpiece after polishing and becomes dirty, it is necessary to perform a cleaning process such as ultrasonic cleaning after the polishing process. , the time required for the cleaning process is increased.

As a means of reducing the amount of wear of the polishing stone, it is conceivable to reduce the difference in relative motion between the workpiece and the polishing stone by reducing the rotation speed of the barrel tank. However, this method is not practical because the pressing force of the grinding stone against the workpiece is weakened, the grinding force is lowered, and the desired amount of chamfering and deburring cannot be obtained. As a method of reducing the wear of the abrasive without lowering the abrasive power, it is conceivable to drastically reconsider the composition design of the abrasive. However, in order to adjust the composition of multiple types of polishing stones with different sizes, hardness, etc., not only is it necessary to make an enormous number of prototypes and a long preparation period, but also the production process must be changed. If not, it will cost a lot of money.

The present invention was completed based on the above circumstances, and an object of the present invention is to reduce the wear of the polishing stone without lowering the polishing power of the polishing stone itself or increasing the cost. do.

The present invention
A barrel polishing method in which a workpiece, a polishing stone, water, and a buffer material are placed in a barrel tank, and the workpiece is polished with the polishing stone,
The median diameter (D50) of the cushioning material is set to 1.2 μm to 2000 μm,
The amount of the cushioning material added is 2 wt % to 30 wt % with respect to the water.

　Because the cushioning material exerts a cushioning effect when the workpiece collides with the grinding stone or when the grinding stones collide with each other, the grinding stones are less likely to wear. Since there is no need to adjust the composition of the polishing stone or change the process significantly, the cost does not increase. Abrasive stone wear can be reduced without increasing cost.

Schematic diagram showing how workpieces, polishing stones, water, cushioning materials, and compounds are put into the barrel tank of the first embodiment. Enlarged perspective view of workpiece Enlarged perspective view of polishing stone Enlarged schematic diagram showing how cushioning material is interposed between abrasive stones

<Embodiment 1>
A first embodiment embodying the present invention will be described below with reference to FIGS. 1 to 4. FIG. The barrel finishing method of Embodiment 1 is performed using a barrel tank 10 that constitutes a centrifugal barrel finishing machine (not shown). During polishing, as shown in FIG. 1, a plurality of workpieces 11, a plurality of polishing stones 12, a predetermined amount of water 13, a cushioning material 14 made of powder, and a compound 15 are placed in a barrel tank 10. is put in. The cushioning material 14 and the compound 15 may be charged into the barrel tank 10 separately, or the cushioning material 14 and the compound 15 may be packed together and charged into the barrel tank 10 . The workpiece 11 may have a shape having at least one plane (a plane with a curvature of 0) or may have a shape having no plane.

An aggregate of the workpiece 11, the polishing stone 12, the water 13, the buffer material 14, and the compound 15 put into the barrel tank 10 is defined as a mass. After the mass is put into the barrel tank 10 , the mass is made to flow within the barrel tank 10 by revolving and rotating the barrel tank 10 . The flow of mass causes a relative motion difference between the polishing stone 12 and the work 11 , and the polishing stone 12 collides with the surface of the work 11 to polish the surface of the work 11 . Polishing is performed mainly for the purpose of smoothing the flat portion 11S of the workpiece 11 and curved surface portions with a small curvature, chamfering the corner portions 11E, and removing burrs.

While polishing is being performed, as shown in FIG. Due to the presence of this cushioning material 14, when the polishing stone 12 collides with the work 11, fine protrusions on the surface of the polishing stone 12 are less likely to enter the recesses of the work 11, and fine protrusions on the surface of the work 11 are prevented from entering. It becomes difficult to get into the concave portion of the polishing stone 12 . As a result, the convex portions of the polishing stone 12 are not excessively ground by collision with the inner surface of the concave portion of the work 11, and the inner surface of the concave portion of the polishing stone 12 is excessively shaved by collision with the convex portion of the work 11. Since it is suppressed, the abrasive stone 12 is less likely to be worn. Similarly, when the grinding stones 12 collide with each other, the projections of one grinding stone 12 are less likely to enter the recesses of the other grinding stone 12, so the grinding stones 12 are less likely to be worn. When the grain size of the cushioning material 14 is larger than that shown in FIG. Since the grinding stone 12 is suppressed from being scraped, the polishing stone 12 is less likely to be worn. Collision between the convex portions of the polishing stone 12 is also less likely to occur, so the polishing stone 12 is less likely to be worn. In this manner, the cushioning material 14 exerts a cushioning effect when the workpiece 11 collides with the grinding stones 12 or when the grinding stones 12 collide with each other, so that the abrasion of the grinding stones 12 is suppressed.

As the material of the cushioning material 14, either an organic fiber material or a synthetic resin material is used. Organic fibrous materials include wood flour, corn cobs, walnuts, peach seeds, and the like. As the synthetic resin material, styrene resin (polystyrene), urethane resin, acrylic resin, or the like can be used. Regarding the size of the cushioning material 14, powder with a median diameter of 1.2 μm to 0.1 mm and granules with a median diameter of 0.1 mm to 2 mm can be used. The cushioning material 14 made of particles having a relatively large median diameter can be recovered and reused after polishing. In particular, the cushioning material 14 made of urethane resin, which has high abrasion resistance, is preferable because it can be repeatedly collected and reused. These materials are commercially available, readily available, and relatively inexpensive in terms of cost. The cushioning material 14 has a lower hardness than the polishing stone 12 and a lower hardness than the workpiece 11 . The New Mohs hardness of the cushioning material 14 is preferably 5 or less.

The material of the cushioning material 14 is preferably elastic. A material having elasticity is a material that can be elastically deformed when the cushioning material 14 is not mixed with the water 13 , and a material that is not elastically deformed when the cushioning material 14 is not mixed with the water 13 . It includes both materials that can be elastically deformed when mixed with to form a slurry. By using the cushioning material 14 having elasticity, the cushioning material 14 and the grinding stone 12 elastically collide with each other, so that the impact at the time of collision is reduced, a sufficient cushioning effect can be obtained, and the abrasion of the grinding stone 12 is reduced. can be suppressed.

In barrel polishing, the entire surface of the workpiece 11 is generally evenly polished. Therefore, when polishing is performed mainly for chamfering or deburring the corner portion 11E of the workpiece 11, the non-polishing area (flat portion 11S or curved surface portion with a small curvature) other than the corner portion 11E and the burr portion is wastefully scraped. It will be. However, according to the barrel polishing method using the cushioning material 14, the polishing amount of the non-polishing target region can be reduced as described below.

In the planar portion 11S and the curved surface portion with a small curvature, which are the non-polishing portions of the workpiece 11, the cushioning materials 14 cover the non-polishing portions in a state of being densely arranged over a wide range. Therefore, when the polishing stone 12 collides with the cushioning material 14 from an oblique direction with respect to the part to be polished, the impacted cushioning material 14 is unlikely to be displaced due to the presence of the adjacent cushioning material 14. The part is easily kept covered with the cushioning material 14 . In this way, since the non-polishing target portion is likely to be held in a state covered with the cushioning material 14, polishing with the polishing stone 12 is difficult to proceed. In addition, since the shock absorbing effect of the shock absorbing material 14 is high, abrasion of the polishing stone 12 is also restrained.

On the other hand, the corners 11E and burrs, which are parts to be polished in the workpiece 11, are also covered with the cushioning material 14. However, when the polishing stone 12 collides with the cushioning material 14 at the corner 11E and the burr, the cushioning material 14 is flipped off from the tip of the corner 11E and the burr, exposing the corner 11E and the burr. , the polishing stone 12 directly contacts and grinds the corner 11E and the burr. Therefore, the corner portion 11E and the burr portion are polished more than the non-polished portion.

According to the polishing method using the cushioning material 14 of the present embodiment, the corner 11E and the burr of the work 11 are effectively polished by the polishing stone 12 in the polishing of the corner 11E and the burr. be able to. On the other hand, the cushioning material 14 suppresses wasteful polishing of the planar portion 11S that is not to be polished and the curved surface portion with a small curvature, thereby minimizing the material loss of the work 11 and the wasteful consumption of the polishing stone 12. be able to.

The inventor of the present invention conducted an experiment to verify how much the type, size, and amount of cushioning material 14 used affect the amount of wear of the grinding stone 12 . Table 1 shows the experimental results and verification results. In the experiment, a centrifugal barrel finishing machine HS-1-4V manufactured by Tipton Co., Ltd. was used. The capacity of the barrel tank 10 used is 1 liter. The rotation speed of the barrel tank 10 is 260 rpm, and the polishing time is 30 minutes.

The work 11 is a 15 mm x 15 mm x 20 mm rectangular parallelepiped (see Fig. 2), and the material of the work 11 is SS400. The grinding stone 12 is GT-4 manufactured by Tipton Co., Ltd. The grinding stone 12 is an equilateral triangular prism with a side of 10 mm and a height of 8 mm (see FIG. 3), and the material of the grinding stone 12 is ceramics. The amount of water 13 introduced into the barrel tank 10 is 0.25 liters. Compound 15 is a powder compound CO-56 manufactured by Tipton Co., Ltd. The input amount of the compound 15 is 1 wt % with respect to the water 13 . That is, the weight ratio of the water 13 and the compound 15 (the weight of the compound 15/the weight of the water 13) in the barrel tank 10 is 0.01.

In the experiment, as the cushioning material 14, wood flour, styrene resin granular material, corn cob (cone), and acrylic resin granular material were used. In the following description, the input amount of the buffer material 14 represents the ratio of the input amount of the buffer material 14 to the input amount of the water 13 into the barrel tank 10 . The input amount of the cushioning material 14=(the weight of the cushioning material 14/the weight of the water 13)×100. The amount of the cushioning material 14 added in the experiment was 0 to 30 wt %.

In Table 1, the wear rate is the ratio of the amount of wear after polishing to the weight of the polishing stone 12 before polishing (the difference between the weight of the polishing stone 12 before polishing and the weight after polishing/the weight of the polishing stone 12 before polishing). ). The wear rate ratio is the ratio of the wear rate of each example or each comparative example (wear rate of each example or each comparative example/ Wear rate of Comparative Example A). For the evaluation of the wear rate, a wear rate ratio of 0.8 or less was rated as "⊚ (particularly good)", and a wear rate rate of 0.9 or less was rated as "◯ (good)". Since the variation in the wear rate ratio when there is no buffer material 14 is about ±10%, the examples where the wear rate ratio is greater than 0.9 are rated as "x (defective)" within the normal variation range. Examples with a wear rate evaluation of “⊚” or “◯” are indicated as examples, and examples with a wear rate evaluation of “×” are indicated as comparative examples.

The R amount is the measured value of the R amount of the corner 11E of the workpiece 11 (the radius of the quarter-arc portion of the corner 11E). As a measuring instrument, 1600GR of Contour Record manufactured by Tokyo Seimitsu Co., Ltd. was used. The R amount ratio is the ratio of the R amount of each example (R amount of each example/R amount of comparative example A) when the R amount of the condition without the buffer material 14 (comparative example A) is 1. be. Since the variation in the R amount ratio when there is no cushioning material 14 is about ±5%, it is judged that the R amount evaluation of the example in which the R amount ratio is larger than 0.95 is within the normal variation range. and "○ (good)". Examples in which the R amount ratio was 0.95 or less were evaluated as "x (defective)" for the R amount evaluation.

When the cushioning material 14 is any one of wood flour, styrene, and corn, and the median diameter (D50) of the cushioning material 14 is 250 μm, the amount of the cushioning material 14 added is 1 wt %. The wear rate evaluation is "x". The wear rate evaluation of Examples 1, 9, and 16 in which the amount of the cushioning material 14 added is 2 wt % is "Good". The wear rate evaluation of Examples 2 to 8, Examples 10 to 15, and Examples 17 to 23 in which the amount of the cushioning material 14 added is 3 wt % to 30 wt % is "excellent".

When the cushioning material 14 is acrylic and the amount of the cushioning material 14 is 3 wt %, the wear rate evaluation of Comparative Example E, in which the median diameter of the cushioning material 14 is 0.15 μm, is "x". The wear rate evaluation of Examples 24 to 28 in which the median diameter of the cushioning material 14 is 1.20 μm to 10.00 μm is “◯”. The wear rate evaluation of Example 29 in which the median diameter of the cushioning material 14 is 50.00 μm is “⊚”.

When the cushioning material 14 is acrylic and the input amount of the cushioning material 14 is 3 wt %, the wear rate evaluation of Example 30 in which the median diameter of the cushioning material 14 is 2000.00 μm is "○". The wear rate evaluation of Comparative Example F, in which the median diameter of the cushioning material 14 is 3000.00 μm, is “×”.

When the cushioning material 14 is acrylic and the median diameter of the cushioning material 14 is 1.20 μm, Example 31 in which the amount of the cushioning material 14 added is 5 wt %, and Example 9 in which the amount of the cushioning material 14 is added is 9 wt %. The wear rate evaluation of No. 32 is "◯". The wear rate evaluation of Examples 33 to 36 in which the amount of the cushioning material 14 added is 20 wt % or more is "A".

When the cushioning material 14 is acrylic and the median diameter of the cushioning material 14 is 2000.00 μm, the wear rate evaluation of Example 37 in which the amount of the cushioning material 14 is 7 wt % is "◯". The wear rate evaluation of Examples 38 to 41 in which the amount of the cushioning material 14 added is 8 wt % to 20 wt % is "A".

There is no significant difference in the wear rate between Example 7 in which the amount of the cushioning material 14 added is 20 wt% and Example 8 in which the amount of the cushioning material 14 added is 30 wt%. There is no significant difference in the wear rate between Example 22 in which the amount of the cushioning material 14 added is 20 wt % and Example 23 in which the amount of the cushioning material 14 added is 30 wt %. Therefore, from the viewpoint of the material cost of the cushioning material 14, the amount of the cushioning material 14 charged is preferably 20 wt % or less.

When the cushioning material 14 is wood flour, the R amount evaluation of Example 4 in which the amount of the cushioning material 14 is 5 wt% and Example 5 in which the amount of the cushioning material 14 is 6 wt% is "○". . When the cushioning material 14 is styrene, the R amount evaluation of Example 11 in which the amount of the cushioning material 14 added is 4 wt % and Example 12 in which the amount of the cushioning material 14 added is 5 wt % is "Good". When the cushioning material 14 is a cone, the R amount evaluation of Example 19 in which the amount of the cushioning material 14 is 5 wt% and Example 20 in which the amount of the cushioning material 14 is 6 wt% is "O". When the cushioning material 14 is acrylic, the R amount evaluation of Example 33 in which the amount of the cushioning material 14 added is 20 wt% and Example 34 in which the amount of the cushioning material 14 added is 28 wt% is "O". When the cushioning material 14 is acrylic, Example 37 in which the amount of the cushioning material 14 is 7 wt%, Example 38 in which the amount of the cushioning material 14 is 8 wt%, and 9 wt% are used. The R amount evaluation of Example 39 is "◯".

Regarding the size of the median diameter of the cushioning material 14, the wear rate evaluation of Comparative Example E, in which the median diameter of the cushioning material 14 was 0.15 μm, and Comparative Example F, in which the median diameter of the cushioning material 14 was 3000 μm, was "x". The wear rate evaluation of Examples 1 to 41 in which the median diameter of the cushioning material 14 was 1.2 μm to 2000 μm was “◯” or “⊚”. If the median diameter of the cushioning material 14 is smaller than 1.2 μm, a sufficient cushioning effect cannot be exhibited. If the median diameter of the cushioning material 14 is larger than 2000 μm, the cushioning material 14 is less likely to intervene between the workpiece 11 and the grinding stone 12 or between the grinding stones 12 . From this result, the median diameter of the cushioning material 14 is preferably 1.2 μm to 2000 μm.

After polishing, the polished work 11 and the polishing stone 12 are sorted, and sludge such as polishing powder of the work 11 and wear powder of the polishing stone 12 is drained, and the inside of the barrel tank 10 is washed. When the median diameter of the cushioning material 14 is larger than 1000 μm, only the grinding stone 12 can be sorted out and collected by sorting means such as a sieve or a filter in the washing step. Running costs can be reduced by reusing the collected cushioning material 14 . Therefore, the median diameter of the cushioning material 14 is more preferably 1000 μm to 2000 μm.

The amount of the cushioning material 14 put into the barrel tank 10 is preferably 2 wt % to 30 wt %. If the amount of the cushioning material 14 added is less than 2 wt %, a sufficient cushioning effect cannot be exhibited. If the amount of the cushioning material 14 added is more than 30 wt %, the cushioning material 14 tends to remain as dirt on the work 11 after polishing.

In the barrel polishing method of Embodiment 1, a work 11, a polishing stone 12, water 13, and a buffer material 14 are put into a barrel tank 10, and the work 11 is polished with the polishing stone 12. The median diameter (D50) of the cushioning material 14 is set to 1.2 μm to 2000 μm. Also, the amount of the cushioning material 14 added is set to 2 to 30 wt % with respect to the water 13 . That is, the weight ratio of the buffer material 14 to the water 13 in the barrel tank 10 (the weight of the buffer material 14/the weight of the water 13) is 0.02 to 0.30. By using the cushioning material 14 with the size and amount set as described above, the cushioning material 14 exerts a high cushioning effect when the workpiece 11 and the grinding stone 12 collide or when the grinding stones 12 collide with each other. , the abrasive stone 12 is less likely to be worn.

By setting the size of the cushioning material 14 and the input amount of the cushioning material 14 within the above range, the abrasion of the grinding stone 12 can be suppressed without reducing the grinding power of the grinding stone 12 itself. In order to achieve both the polishing power of the polishing stone 12 and the reduction of the wear of the polishing stone 12, there is no need to adjust the composition of a plurality of types of polishing stones 12 having different sizes, hardness, etc., so that a huge number of trial productions and long-term production are possible. There is no need for a long preparation period, and there is no need to change the production process. Therefore, it is possible to avoid an increase in cost due to adjustment of the composition of the grinding stone 12 . According to this embodiment, the abrasion of the polishing stone 12 can be reduced without lowering the polishing power of the polishing stone 12 itself or increasing the cost.

When wood powder or styrene is used as an additive in barrel polishing, an effect of preventing the plate-shaped workpiece 11 from sticking to other workpieces 11 or the inner wall of the barrel tank 10 can be expected. The amount of the additive added to water is preferably 1 wt % to 2 wt %. Adding more than 2 wt % of the additive to water is not preferable from the viewpoint of cost because the anti-sticking effect becomes excessive. The cushioning material 14 used in the barrel polishing method of the present embodiment has an input amount (addition amount) of 2 wt % or more with respect to the water 13 , unlike the additive for sticking prevention.

As the amount of the cushioning material 14 added increases, the interference effect of the cushioning material 14 increases. Become. Therefore, considering the usage amount of the cushioning material 14, it is preferable to set the amount of the cushioning material 14 to be 20 wt % or less.

If the amount of the cushioning material 14 added is less than 3 wt %, the effect of reducing the wear of the grinding stone 12 is low. When the amount of the cushioning material 14 added is 3 wt % or more, the effect of reducing the abrasion of the grinding stone 12 is enhanced. If the amount of the cushioning material 14 added is more than 6 wt %, the cushioning material 14 tends to remain on the corner 11E of the work 11 and the burrs without being flipped off when the abrasive stone 12 collides with it, resulting in chamfering of the corner 11E. It becomes easy to reduce the amount of burrs and the amount of burrs removed from the burrs. If the input amount of the buffer material 14 is 6 wt % or less, the buffer material 14 is likely to be flipped off when the abrasive stone 12 collides with the corner portion 11E or the burr portion of the work 11, so the corner portion 11E or the burr portion is worn. more effective. Therefore, the amount of the cushioning material 14 to be added is preferably 3 wt % to 6 wt %.

As the compound 15, one made of a lubricating material can be used. In this case, the compound 15 makes the polishing stone 12 slippery on the planar portion 11S of the work 11, so that the contact area between the work 11 and the polishing stone 12 increases. As a result, the polishing efficiency of the planar portion 11S of the workpiece 11 is improved.

As the compound 15, a material made of a material that exhibits an etching function on the workpiece 11 can be used. When the compound 15 that exhibits the etching function is put in, the surface of the work 11 becomes brittle and easily scraped by etching, or melts and becomes easily scraped, so polishing efficiency on the surface of the work 11 is improved. Further, when the compound 15 containing abrasive grains is used, the polishing efficiency on the surface of the workpiece 11 is improved by the abrasive grains.

When the cushioning material 14 is made of a material containing a resin component such as wood flour, the compound 15 is preferably made of a material that does not contain a fatty acid salt. When the buffer material 14 contains a resin component, the pH of the water 13 in the barrel tank 10 is lowered due to the effect of the resin component. If compound 15 contains a fatty acid salt, free fatty acids are generated from compound 15 due to the decrease in pH. Since the free fatty acid is oily, there is a concern that it will adhere to the surfaces of the workpiece 11, the polishing stone 12, and the cushioning material 14 as dirt. By using the compound 15 containing no fatty acid salt, it is possible to prevent free fatty acid stains from adhering to the surfaces of the workpiece 11, the polishing stone 12, and the cushioning material 14. FIG.

The polishing stone 12 preferably has a shape having a flat portion 12S, as shown in FIG. If the polishing stone 12 has a shape such as a sphere that does not have a flat portion 12S, for example, when it collides with another polishing stone 12, it always makes a point contact. It is difficult to obtain the wear reduction effect of No. 12. On the other hand, if the polishing stones 12 are shaped to have flat portions 12S, the flat portions 12S come into face contact with each other when the polishing stones 12 collide with each other. In this case, the cushioning material 14 is likely to intervene between the flat portions 12S, so the abrasion reduction effect of the polishing stone 12 is enhanced.

<Other Examples>
The present invention is not limited to the embodiments explained by the above description and drawings, and the following embodiments are also included in the technical scope of the present invention.
The cushioning material may be an organic fibrous material other than wood flour, corn cobs and walnuts.
The cushioning material may be a synthetic resin material other than styrene resin, urethane resin, and acrylic resin.
The cushioning material may be a material other than organic fibrous materials and synthetic resin materials.
The hardness of the cushioning material may be the same as that of the abrasive stone.
The hardness of the cushioning material may be the same as that of the workpiece.
The neo-Mohs hardness of the cushioning material may be higher than 5.
The cushioning material may be a non-elastic material.
The workpiece may be polished without adding compound.
The compound may consist of a non-lubricating material.
The compound may consist of a material that does not exhibit an etching function.
The compound may be free of abrasive grains.
The compound may be a material containing fatty acid salts.
The compound is not limited to a powdery compound, and may be a liquid compound.
The workpiece may have a shape that does not have a flat portion.

DESCRIPTION OF SYMBOLS 10... Barrel tank 11... Work 12... Polishing stone 12S... Plane part of polishing stone 13... Water 14... Cushioning material 15... Compound

Claims

A barrel polishing method in which a workpiece, a polishing stone, water, and a buffer material are placed in a barrel tank, and the workpiece is polished with the polishing stone,
The median diameter (D50) of the cushioning material is set to 1.2 μm to 2000 μm,
A barrel polishing method in which the amount of the buffer material added is 2 wt % to 30 wt % with respect to the water.
The barrel polishing method according to claim 1, wherein the amount of the buffer material added is 2 wt% to 20 wt% with respect to the water.
The barrel polishing method according to claim 1, wherein the amount of the buffer material added is 3 wt% to 6 wt% with respect to the water.
The barrel polishing method according to any one of claims 1 to 3, wherein the cushioning material is either an organic fibrous material or a synthetic resin material.
The barrel polishing method according to claim 4, wherein the cushioning material is wood flour, corn cob, walnut, styrene resin, urethane, or acrylic resin.
The barrel polishing method according to any one of claims 1 to 5, wherein the cushioning material has a hardness lower than that of the polishing stone.
The barrel polishing method according to any one of claims 1 to 6, wherein the cushioning material has a hardness lower than that of the work.
The barrel polishing method according to any one of claims 1 to 6, wherein the cushioning material has a New Mohs hardness of 5 or less.
The barrel polishing method according to any one of claims 1 to 8, wherein the median diameter (D50) of the cushioning material is 1000 µm to 2000 µm.
The buffer material is made of a material containing a resin component,
10. The barrel polishing method according to any one of claims 1 to 9, wherein a compound made of a material containing no fatty acid salt is charged into the barrel tank.
The barrel polishing method for suppressing abrasion of the polishing stone according to any one of claims 1 to 10, wherein the polishing stone has a shape having a flat portion.
A cushioning material used in the barrel polishing method according to any one of claims 1 to 11.