Abrasive tool

Abstract

To provide a polishing tool which inhibits uneven distribution of an abrasive powder in a pipe.SOLUTION: A polishing tool 10 polishes an inner wall surface W1a of a pipe W1. The polishing tool 10 includes: multiple polishing bodies 3; and a water-soluble capsule 6 containing an abrasive powder 7 therein. The water-soluble capsule 6 is disposed between the multiple polishing bodies 3. When water is supplied to the inner side of the pipe W1, the water melts at least a part of the water-soluble capsule 6 to discharge the abrasive powder 7 to the outside of the water-soluble capsule 6. The action allows the abrasive powder 7 to be supplied to an area between the multiple polishing bodies 3. Thus, uneven distribution of the abrasive powder 7 can be inhibited in the pipe W1.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to abrasive tools, and particularly to abrasive tools for polishing the inner wall surface of pipes.

Background Art

[0002] Patent Document 1 discloses an abrasive tool provided with abrasive bodies. The abrasive bodies are discretely fixed to a synthetic resin filamentous core material. While flowing an abrasive grain slurry in which abrasive grains are dispersed in water inside a metal pipe, the abrasive tool is inserted inside the metal pipe and the core material is pulled to polish the inner diameter surface of the metal pipe.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventors of the present application have discovered the following problems. When polishing the inner wall surface of a pipe using such an abrasive tool, while flowing an abrasive grain slurry inside the pipe, the abrasive tool is inserted inside the pipe. A plurality of abrasive bodies located on the upstream side may retain only the abrasive grains in the abrasive grain slurry. As a result, the abrasive grain slurry has the abrasive grains removed and water remaining. The abrasive bodies located on the downstream side are supplied with water but hardly supplied with abrasive grains. As a result, the distribution of the abrasive grains in the pipe is biased. There is a risk that a portion of the pipe where the abrasive grains are insufficient cannot be sufficiently polished.

[0005] An object of the present invention is to provide an abrasive tool that suppresses the bias in the distribution of the abrasive in the pipe in view of the above problems.

Means for Solving the Problems

[0006] The abrasive tool according to the present invention is A polishing tool for polishing the inner wall surface of a pipe, a plurality of polishing bodies, and a water-soluble capsule containing an abrasive, and the water-soluble capsule is disposed between the plurality of polishing bodies.

[0007] According to such a configuration, when water is supplied to the inside of the pipe, at least a part of the water-soluble capsule is dissolved, and the abrasive is released to the outside of the water-soluble capsule. As a result, the abrasive can be supplied between the plurality of polishing bodies. Therefore, it is possible to suppress the uneven distribution of the abrasive in the pipe.

Advantages of the Invention

[0008] The present invention can suppress the uneven distribution of the abrasive in the pipe.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0010] Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. Also, for clarity of explanation, the following description and drawings are appropriately simplified.

[0011] (Embodiment 1) Embodiment 1 will be described with reference to FIGS. 1 and 2. FIGS. 1 and 2 are schematic diagrams showing one step of an example of a polishing method using the polishing tool according to Embodiment 1.

[0012] Of course, the right-handed xyz coordinates shown in FIG. 1 and other drawings are for convenience in explaining the positional relationship of the components. Usually, the positive z-axis direction is vertically upward, the xy plane is a horizontal plane, and they are common among the drawings.

[0013] As shown in FIG. 1, the abrasive tool 10 includes a plurality of abrasive bodies 3 and water-soluble capsules 6. An example of the abrasive tool 10 shown in FIG. 1 may include a first clamping portion 1, a second clamping portion 2, and strings 4 and 5. The inner wall surface W1a of the pipe W1, which is the object to be polished, can be polished using the abrasive tool 10.

[0014] The first clamping portion 1 and the second clamping portion 2 may clamp a plurality of abrasive bodies 3. The first clamping portion 1 and the second clamping portion 2 may have the size and mechanical strength necessary for clamping the abrasive body 3. The first clamping portion 1 and the second clamping portion 2 can take various shapes. An example of the first clamping portion 1 and the second clamping portion 2 shown in FIG. 1 is two plate-like bodies. The first clamping portion 1 may have a hole 1a through which the string 4 can pass. The second clamping portion 2 may have a hole 2a through which the string 5 can pass.

[0015] The plurality of abrasive bodies 3 may be arranged between the first clamping portion 1 and the second clamping portion 2. The plurality of abrasive bodies 3 may be clamped between the first clamping portion 1 and the second clamping portion 2. The plurality of abrasive bodies 3 may all have a size that allows them to pass through the pipe W1. Specifically, the diameter D3 of the plurality of abrasive bodies 3 may all be smaller than the inner diameter D1 of the pipe W1. When the abrasive body 3 receives a predetermined compressive stress, it may deform so as to protrude in the vertical direction with respect to the compressive stress. The abrasive body 3 may be made of a material having deformability. The abrasive body 3 may be made of a material having the mechanical strength and hardness necessary for polishing the object to be polished. The abrasive body 3 may have higher water resistance compared to the water-soluble capsule 6. Examples of such materials include elastic materials such as rubber. An abrasive agent may be added to such an elastic material. When the pipe W1 is made of a metal material, the abrasive body 3 may be made of an elastic material such as rubber.

[0016] The grinding body 3 has holes 3a, and the holes 3a may penetrate the grinding body 3. The holes 3a may have a cross-sectional area large enough for the strings 4 and 5 to pass through simultaneously. An example of the grinding body 3 shown in FIGS. 1 and 2 is three. The grinding body 3 can take various shapes. An example of the grinding body 3 shown in FIGS. 1 and 2 is spherical. The grinding bodies 3 shown in FIGS. 1 and 2 are arranged in a row between the first clamping portion 1 and the second clamping portion 2.

[0017] The total length of the string 4 may be longer than the length L1 of the tube W1. One end 4a of the string 4 is attached to the second clamping portion 2. The string 4 passes through the holes 3a of the plurality of grinding bodies 3. An example of the string 4 shown in FIGS. 1 and 2 passes through all the holes 3a of three spherical bodies which are an example of the plurality of grinding bodies 3. The string 4 passes through the side surface of the water-soluble capsule 6 or its vicinity between the plurality of grinding bodies 3. When the first clamping portion 1 has a hole 1a, the string 4 may pass through the hole 1a. The first clamping portion 1 is arranged between one end 4a and the other end 4b of the string 4. When the other end 4b of the string 4 is pulled away from the plurality of grinding bodies 3, one end 4a of the string 4 pulls the second clamping portion 2 toward the plurality of grinding bodies 3 side. Thereby, the second clamping portion 2 is brought closer to the first clamping portion 1 side.

[0018] The total length of the string 5 may be longer than the length L1 of the tube W1. One end 5a of the string 5 is attached to the first clamping portion 1. The string 5 passes through the holes 3a of the plurality of grinding bodies 3. An example of the string 5 shown in FIGS. 1 and 2 passes through all the holes 3a of three spherical bodies which are an example of the plurality of grinding bodies 3. The string 5 passes through the side surface of the water-soluble capsule 6 or its vicinity between the plurality of grinding bodies 3. When the second clamping portion 2 has a hole 2a, the string 5 may pass through the hole 2a. The second clamping portion 2 is arranged between one end 5a and the other end 5b of the string 5. When the other end 5b of the string 5 is pulled away from the plurality of grinding bodies 3, one end 5a of the string 5 pulls the first clamping portion 1 toward the plurality of grinding bodies 3 side. Thereby, the first clamping portion 1 is brought closer to the second clamping portion 2 side.

[0019] The string 4 and the string 5 may function as a technical proximity means for bringing the first clamping portion 1 and the second clamping portion 2 closer.

[0020] The water-soluble capsule 6 may contain the abrasive 7 and can take various shapes. An example of the water-soluble capsule 6 shown in FIG. 1 is a spherical body or a columnar body. The water-soluble capsule 6 is disposed between a plurality of abrasive bodies 3. The water-soluble capsule 6 may be disposed among all of the plurality of abrasive bodies 3. The water-soluble capsule 6 includes at least a part made of a material soluble in water. Note that when the water-soluble capsule 6 is in contact with water and further receives a predetermined compressive stress, the water-soluble capsule 6 dissolves or cracks, and the abrasive 7 is easily released to the outside of the water-soluble capsule 6. The abrasive 7 is preferably smaller than at least the abrasive body 3. The abrasive 7 is preferably a plurality of abrasive grains made of a material having the mechanical strength and hardness necessary for polishing the object to be polished.

[0021] (Polishing method) Next, with reference to FIGS. 1 and 2, a polishing method for polishing the inner wall surface W1a of the pipe W1 of the object to be polished using the polishing tool 10 will be described.

[0022] As shown in FIG. 1, the polishing tool 10 is inserted into the pipe W1, and the abrasive body 3 is disposed near the inner wall surface W1a of the pipe W1 (step ST1). While extending the polishing tool 10 in the axial direction of the pipe W1 (here, the X-axis direction), the polishing tool 10 may be inserted into the pipe W1 while the abrasive body 3 is separated from the inner wall surface W1a of the pipe W1. Specifically, while one of the strings 4 and 5 is disposed outside the pipe W1, the polishing tool 10 is inserted into the pipe W1. By flowing a fluid, the other of the strings 4 and 5 is passed through the downstream opening in the pipe W1 and led out to the outside of the pipe W1. As the fluid, for example, water can be used.

[0023] Subsequently, as shown in FIG. 2, water is supplied to the pipe W1 (step ST2). Specifically, water or abrasive slurry containing water is poured inside the pipe W1. The water contacts the water-soluble capsule 6 and dissolves at least a part of the water-soluble capsule 6. Thereby, the abrasive 7 is released outside the water-soluble capsule 6. It is preferable that the part where the water-soluble capsule 6 is dissolved is the part facing the inner wall surface W1a of the pipe W1 because the abrasive 7 easily moves to the inner wall surface W1a of the pipe W1. The abrasive 7 moves from between the plurality of abrasive bodies 3 to the inner wall surface W1a of the pipe W1. At least one of the abrasive body 3 and the abrasive 7 abuts on the inner wall surface W1a of the pipe W1. Further, by moving the abrasive tool 10 in the pipe W1, the inner wall surface W1a of the pipe W1 can be polished.

[0024] From the above, the abrasive 7 can be supplied between the plurality of abrasive bodies 3. Therefore, it is possible to suppress the uneven distribution of the abrasive 7 in the pipe W1. As a result, the abrasive 7 can be uniformly distributed over the entire plurality of abrasive bodies 3 in the pipe W1. Therefore, almost all regions of the inner wall surface W1a of the pipe W1 can be polished uniformly.

[0025] In addition, in step ST2 of the polishing method described above, while supplying water to the pipe W1, the first clamping portion 1 and the second clamping portion 2 may be brought closer to each other. Specifically, the other end 4b of the string 4 may be pulled so as to be separated from the plurality of abrasive bodies 3, and the other end 5b of the string 5 may be pulled so as to be separated from the plurality of abrasive bodies 3. By these operations, the first clamping portion 1 and the second clamping portion 2 are brought closer to each other. The first clamping portion 1 and the second clamping portion 2 apply compressive stress to the plurality of abrasive bodies 3, and the plurality of abrasive bodies 3 press the water-soluble capsule 6. By this pressing, the water-soluble capsule 6 is broken or crushed, and the release of the abrasive 7 outside the water-soluble capsule 6 is promoted.

[0026] (Application Example) An example of the pipe W1 shown in FIGS. 1 and 2 extends on a straight line, but the pipe W1 may extend on a virtual curve in a three-dimensional space. The virtual curve may include a plurality of bent portions. The pipe W1 is, for example, a cooling circuit, an oil passage, or the like. A structure having the pipe W1 extending on a virtual curve in a three-dimensional space can be manufactured using metal additive manufacturing (AM). When a structure having the pipe W1 extending on a virtual curve in a three-dimensional space is manufactured using metal additive manufacturing, melt-down may occur, and surface roughness may occur on the upper part of the pipe W1. The surface roughness causes stress concentration and is a cause of failure. When the surface roughness occurs on the upper part of the pipe W1, the inner wall surface W1a of the pipe W1 can be polished using the polishing tool 10 shown in FIGS. 1 and 2, and the inner wall surface W1a can be smoothed to eliminate the surface roughness.

[0027] Note that the present invention is not limited to the above-described embodiments, and can be appropriately modified without departing from the spirit thereof. Further, the present invention may be implemented by appropriately combining the above-described embodiments and examples thereof.

Explanation of Reference Numerals

[0028] 10 Polishing tool 1 First clamping portion 1a Hole 2 Second clamping portion 2a Hole 3, 13, 13a, 13b, 13c Polishing body 3a Hole 4, 5 String 4a, 5a One end 4b, 5b The other end 6 Water-soluble capsule 7 Abrasive W1 Pipe W1a Inner wall surface D1 Inner diameter L1 Length

Claims

**Claim 1** A polishing tool for polishing the inner wall surface of a pipe, comprising: a plurality of abrasive bodies; and a water-soluble capsule containing an abrasive agent, wherein the water-soluble capsule is disposed between the plurality of abrasive bodies, the water-soluble capsule comes into contact with water, at least a part of the water-soluble capsule dissolves, and the abrasive agent is released to the outside of the water-soluble capsule, and the water-soluble capsule is cracked by being pressed by the plurality of abrasive bodies. A polishing tool.

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