WO2020262562A1

WO2020262562A1 - Device for polishing metal pipe inner surface, and metal pipe

Info

Publication number: WO2020262562A1
Application number: PCT/JP2020/025109
Authority: WO
Inventors: 泰治福本; 中島　実; 忠士川口
Original assignee: 大阪サニタリー株式会社
Priority date: 2019-06-25
Filing date: 2020-06-25
Publication date: 2020-12-30
Also published as: EP3991914A1; CN114007811A; JP2021003748A; CN114007811B; JP6663067B1; EP3991914A4

Abstract

In the present invention, a jig 21 includes: elastic brushes 44 protruding in a radial direction that is orthogonal to a shaft 23; and a tube 46 disposed more on the inner side in the radial direction than the brushes 44. The dimension between the shaft 23 and the tips of the brushes 44 is at least half of the inner diameter of a stainless steel pipe 1. When the jig 21 is disposed inside the stainless steel pipe 1, the tube 46 pushes the brushes 44 outward in the radial direction, thereby tips of the brushes 44 abut the inner surface of the stainless steel pipe 1 while remaining erect, applying an internal pressure. This configuration causes the polishing agent supplied from a pump 12 to adhere to the inner surface of the stainless steel pipe 1. The polishing agent adhered to the inner surface of the stainless steel pipe 1 is pressed against the inner surface of the stainless steel pipe 1 by the brushes 44.

Description

Inner surface polishing device for metal pipes and metal pipes

The present invention relates to an inner surface polishing device for a metal pipe and a metal pipe whose inner surface has been polished using the device.

Conventionally, when polishing the inner surface of a metal pipe, a method is known in which a base treatment is performed with an abrasive having a small count and then the inner surface is finished and polished with an abrasive having a large count. Such a polishing method is adopted in so-called vertical polishing (see Patent Document 1) in which a polishing belt is pressed against the inner surface of a metal pipe and the inner surface of the metal pipe is polished by moving the polishing belt in the longitudinal direction of the metal pipe. Has been done.

Japanese Unexamined Patent Publication No. 11-188594

However, the vertical polishing described in Patent Document 1 has a problem that the surface of the inner surface of the metal pipe after polishing is rough. Therefore, for example, it is not preferable for a pipe used in a manufacturing facility for chemicals or foods, and a metal pipe having an inner surface having a smaller surface roughness is desired.

Further, in the vertical polishing described in Patent Document 1, there is a problem that dust generated when polishing the inner surface of a metal pipe is scattered in the atmosphere and the polishing time becomes long because the worn polishing belt is replaced with a new polishing belt. There is.

Therefore, the present invention has been made to solve the above-mentioned problems, and is an inner surface polishing device for a metal pipe capable of forming a metal pipe having a mirror-finished inner surface, and the inner surface is polished using the device. The purpose is to provide metal pipes.

The present invention further provides an inner surface polishing device for metal pipes, which prevents dust generated during polishing from scattering into the atmosphere and can shorten the polishing time as compared with conventional vertical polishing, and the inner surface is polished using the device. The purpose is to provide metal pipes.

The inner surface polishing device for a metal pipe according to the present invention is an inner surface polishing device for a metal pipe that polishes the inner surface of the metal pipe to be polished, and has a rotating body extending in the axial direction and the rotating body around the axis. The rotating body is provided with a driving means for rotating and a supply means for supplying a polishing liquid in which a granular polishing agent and a liquid are mixed inside the metal pipe, and the rotating body projects in a radial direction orthogonal to the axis. It has an elastic brush and an inner elastic body arranged radially inside the brush, and the dimension between the shaft and the tip of the brush is at least half of the inner diameter of the metal pipe. With the rotating body arranged inside the metal pipe, the inner elastic body presses the brush outward in the radial direction, so that the tip of the brush is in contact with the inner surface of the metal pipe while standing upright. By applying an internal pressure to the inner surface of the metal pipe, the polishing agent supplied from the supply means to the inner surface of the metal pipe adheres to the inner surface of the metal pipe while being attached to the inner surface of the metal pipe by the tip of the brush. By being pressed against the inner surface, the inner surface is polished.

In the present invention, the "metal pipe" is a metal pipe, a metal tubular member, or a metal tube. In the present invention, the "metal pipe inner surface polishing device" is defined as "metal pipe inner surface polishing device", "metal tubular member inner surface polishing device", or "metal tube inner surface polishing device". It is a device.

Further, in the present invention, the "brush having elasticity protruding in the radial direction orthogonal to the axis" is not only when all the brushes have elasticity protruding in the radial direction orthogonal to the axis, but also a part of the brush. Includes having elasticity protruding in the radial direction orthogonal to the axis. For example, when the brush has a plurality of bristles, the brush having the elasticity of a part of the plurality of bristles protruding in the radial direction orthogonal to the axis is the "brush having the elasticity protruding in the radial direction orthogonal to the axis". .. When the brush has a plurality of bristles, the brush having the elasticity of all the bristles protruding in the radial direction orthogonal to the axis is the "brush having the elasticity protruding in the radial direction orthogonal to the axis".
Further, in the present invention, "the tip of the brush abuts on the inner surface of the metal pipe" means that the brush has a plurality of bristles and the plurality of bristles of the brush face the inner surface of the metal pipe. This includes not only the case where the tip of the bristles abuts on the inner surface of the metal pipe but also the case where the tip of a part of the bristles of the brush abuts on the inner surface of the metal pipe. The inner elastic body is preferably elastically displaceable in the radial direction of the rotating body.

According to the inner surface polishing device of the present embodiment, the dimension between the shaft and the tip of the brush is more than half of the inner diameter of the metal pipe, and the inner elastic body is elastically displaced in the radial direction. When the rotating body is inserted inside the metal pipe, the inner elastic body elastically displaced inward in the radial direction presses the brush inward in the radial direction, so that the tip of the brush remains upright and the inner surface of the metal pipe. The internal pressure is applied to the inner surface of the metal pipe while contacting the metal pipe. In this state, the polishing liquid supplied to the inside of the metal pipe by rotating the rotating body by the driving means is pressed against the inner surface of the metal pipe by the tip of the brush and adheres to the inner surface of the metal pipe. To do. The brush rotates about an axis with an internal pressure applied to the inner surface of the metal pipe via an abrasive adhering to the inner surface of the metal pipe. The abrasive between the brush and the inner surface of the metal pipe moves in the circumferential direction together with the brush while being pressed against the inner surface of the metal pipe by the brush. As a result, the inner surface of the metal pipe is polished to form a stainless steel pipe whose inner surface is mirror-finished.

In the metal pipe inner surface polishing apparatus according to the present invention, the metal pipe inner surface is in contact with the metal pipe inner surface while the tip of the brush is upright in a state where the rotating body is arranged inside the metal pipe. It is preferable to load an internal pressure of 80 N or more. It is preferable that an internal pressure of 300 N or less is applied to the inner surface of the metal pipe while the rotating body is arranged inside the metal pipe and the tip of the brush is in contact with the inner surface of the metal pipe while standing upright. With the rotating body arranged inside the metal pipe, the inner surface of the metal pipe may be loaded with an internal pressure of 80 N or more and 300 N or less while the tip of the brush is in contact with the inner surface of the metal pipe while standing upright. More preferred.

When the internal pressure is smaller than 80N, the force with which the tip of the brush presses the abrasive against the inner surface of the stainless steel pipe becomes weak, and it tends to be difficult to polish. By applying an internal pressure of 80 N or more to the inner surface of the metal pipe, it is possible to prevent the inner surface of the metal pipe from becoming difficult to polish. When the internal pressure is larger than 300N, the brush tends to bend and it becomes difficult to stand up. By applying an internal pressure of 300 N or less to the inner surface of the metal pipe, it is possible to prevent the brush from becoming difficult to bend.

In the inner surface polishing device for a metal pipe according to the present invention, the rotating body has a brush receiver that supports the brush and the inner elastic body arranged radially inside the brush, and the brush receiver is the brush receiver. It is preferable that the brush is supported so as to be movable in the radial direction.

When the inner elastic body elastically displaced inward in the radial direction presses the brush outward in the radial direction, the tip of the brush stays upright and comes into contact with the inner surface of the metal pipe while being in contact with the inner surface of the metal pipe. The internal pressure will be reliably applied. As a result, the abrasive is easily pressed against the inner surface of the metal pipe.

In the inner surface polishing apparatus for a metal pipe according to the present invention, it is preferable that the brush receiver has side walls arranged on both sides of the brush, and the side walls support the brush so as to be movable in the radial direction. ..

Since the side wall of the brush receiver supports the brush so as to be movable in the radial direction, the tip of the brush stands up when the inner elastic body elastically displaced inward in the radial direction presses the brush in the outward direction in the radial direction. While keeping the contact with the inner surface of the metal pipe, the internal pressure is surely applied to the inner surface of the metal pipe. As a result, the abrasive is easily pressed against the inner surface of the metal pipe by the brush.

In the inner surface polishing device for a metal pipe according to the present invention, the rotating body has a main body extending in the axial direction of the rotating body, the brush is arranged on the radial outer side of the main body, and the inner elastic body is , It is preferable that it is arranged between the main body and the brush.

With the above configuration, the inner elastic body can be configured to press the brush outward in the radial direction. Further, in the above configuration, the inner elastic body may directly press the brush. The structure in which the inner elastic body directly presses the brush makes it easier for the abrasive to be pressed against the inner surface of the metal pipe.

In the inner surface polishing device for a metal pipe according to the present invention, the brush is arranged along the axial direction of the rotating body, and the inner elastic body is radially inside the brush along the axial direction of the rotating body. It is preferable that they are arranged.

According to the above configuration, the inner elastic body can press the brush over the entire axial direction of the rotating body. In addition, the brush can be pressed uniformly over the entire axial direction of the rotating body. As a result, on the inner surface of the metal pipe, the entire abrasive between the brush and the inner surface of the metal pipe is surely pressed against the inner surface of the metal pipe.

In the inner surface polishing device for a metal pipe according to the present invention, the rotating body has a plurality of the brushes, and the plurality of the brushes are arranged apart from each other in the radial direction of the rotating body, and are arranged in the radial direction of the rotating body. It is preferable that a space is formed between the two adjacent brushes.

According to the above configuration, a space is formed between two adjacent brushes of the rotating body in a state where the rotating body is arranged inside the metal pipe. When the polishing liquid is supplied to the inside of the metal pipe by the supply means, the polishing liquid passes through the space between two adjacent brushes of the rotating body and spreads from one end to the other end of the metal pipe. This makes it possible to attach the abrasive to the inner surface of the metal pipe from one end to the other end of the metal pipe.

In the metal pipe inner surface polishing apparatus according to the present invention, it is preferable that a plurality of the brushes are arranged at equal intervals in the circumferential direction of the rotating body.

Since a plurality of brushes are arranged at equal intervals in the circumferential direction of the rotating body, the internal pressure applied to the inner surface of the metal pipe by the tip of each brush becomes almost the same. As a result, the inner surface of the metal pipe can be uniformly polished in the circumferential direction.

In the inner surface polishing device for a metal pipe according to the present invention, the rotating body has a plurality of the brushes and a plurality of the brush receivers, and each of the plurality of brush receivers supports each of the plurality of brushes. However, it is preferable that the plurality of the brushes and the brush receivers supporting the brushes are arranged at equal intervals in the circumferential direction of the rotating body.

Since a plurality of brushes are arranged at equal intervals in the circumferential direction of the rotating body, the internal pressure applied to the inner surface of the metal pipe by the tip of each brush becomes almost the same. Further, since all the brushes are supported so as to be movable in the radial direction by the brush receiver, the internal pressure is surely applied to the inner surface of the metal pipe by all the brushes. As a result, the inner surface of the metal pipe can be uniformly polished in the circumferential direction.

In the metal pipe inner surface polishing apparatus according to the present invention, when the tip of the brush is in contact with the inner surface of the metal pipe in a state where the rotating body is arranged inside the metal pipe, the tip of the brush It is preferable that at least a part of the portion is perpendicular to the tangent line at the contact point in contact with the inner surface of the metal pipe.

When the tip of the brush is in contact with the inner surface of the metal pipe with the rotating body arranged inside the metal pipe, at least a part of the tip of the brush is in contact with the inner surface of the metal pipe. When perpendicular to the tangent, the portion perpendicular to the tangent at the contact point in contact with the inner surface of the metal pipe reliably presses the inner surface of the metal pipe in the radial direction. As a result, the abrasive between the brush and the inner surface of the metal pipe is surely pressed against the inner surface of the metal pipe, so that the metal pipe having a mirror-finished inner surface can be formed.

In the inner surface polishing device for a metal pipe according to the present invention, it is preferable that the driving means moves the rotating body along the shaft while rotating the rotating body around the shaft.

By moving the rotating body along the axis while rotating the rotating body around the axis, the inner surface of the metal pipe can be polished even if the metal pipe is longer than the rotating body.

In the inner surface polishing apparatus for a metal pipe according to the present invention, it is preferable that a plurality of the rotating bodies are connected in the axial direction thereof via a shaft. Further, it is preferable that the distance between the rotating bodies adjacent to each other in the axial direction is shorter than the axial length of the rotating bodies.

With the above configuration, by connecting a plurality of rotating bodies according to the length of the metal pipe, even if the length is, for example, 4 m or more, the plurality of rotating bodies apply the abrasive to the metal pipe. It can be polished by pressing it against the inner surface of the.

In the inner surface polishing device for a metal pipe according to the present invention, the inner elastic body is compressed while the rotating body is installed inside the metal pipe, and the inner elastic body pushes the brush radially outward. It is preferable to press the metal elastically.

With the above configuration, the brush reliably applies internal pressure to the inner surface of the metal pipe. As a result, the abrasive disposed between the tip of the brush and the inner surface of the metal pipe is surely pressed against the inner surface of the metal pipe.

The metal pipe according to the present invention has an arithmetic average roughness (Ra) of the inner surface polished by the above-mentioned inner surface polishing device of less than 0.1 μm. By the above-mentioned inner surface polishing apparatus, a metal pipe having a mirror-finished inner surface can be obtained.

The inner surface of the metal pipe according to the present invention is polished by the above-mentioned inner surface polishing device, and the length is 4 m or more. With the inner surface polishing device, a long metal pipe having a mirror-finished inner surface can be obtained.

The "metal pipe" according to the present invention is a metal pipe, a metal tubular member, or a metal tube.

In the present invention, the dimension between the shaft of the rotating body and the tip of the brush is more than half of the inner diameter of the metal pipe, and the inner elastic body is elastically displaced. As a result, when the rotating body is inserted inside the metal pipe, the inner elastic body elastically displaced by the brush moving inward elastically presses the brush outward in the radial direction. As a result, the tip of the brush pressed outward in the radial direction is in contact with the inner surface of the metal pipe while standing upright, and the internal pressure is applied. Then, when the rotating body arranged inside the metal pipe is rotated while the polishing liquid is supplied, the tip of the brush is pressed against the inner surface of the metal pipe while maintaining the upright state, and the metal pipe Abrasive adheres to the inner surface. While the brush applies internal pressure to the metal pipe via the abrasive, the rotating body rotates around the axis, and the abrasive adhering to the inner surface of the metal pipe polishes the inner surface of the metal pipe in the circumferential direction. This makes it possible to form a metal pipe whose inner surface is mirror-finished. Further, since the dust generated when polishing the inner surface of the metal pipe is mixed in the polishing liquid, it is possible to prevent the dust from scattering into the atmosphere. Further, the liquid can absorb and cool the frictional heat generated by the polishing agent polishing the inner surface of the metal pipe. On the other hand, if the inner surface of the metal pipe is polished with a file, it takes time and effort to replace the worn file with a new file. However, since the abrasive polishes the inner surface of the metal pipe, the rotating body itself does not wear. Therefore, since it is possible to save the trouble of replacing the rotating body with a new one, the polishing time can be shortened as compared with the case of using a file.

It is the schematic sectional drawing of the inner surface polishing apparatus of the metal pipe which concerns on embodiment of this invention. It is a partially enlarged top view which shows a plurality of jigs connected with a shaft. It is sectional drawing of the jig along the line AA of FIG. It is sectional drawing of a metal pipe. It is schematic cross-sectional view which shows the inner surface polishing apparatus in the process of arranging a metal pipe. It is the schematic sectional drawing which shows the inner surface polishing apparatus which arranged and fixed the metal pipe. It is a partially enlarged top view in the middle of moving a metal pipe from the other end of the jig unit toward one end. It is a partially enlarged top view of the other end of the jig unit which shows the state which the metal pipe is positioned. It is an enlarged cross-sectional view which shows a part of the jig inserted in the metal pipe. 9 is a partially enlarged cross-sectional view showing a brush tip portion of FIG. FIG. 5 is a cross-sectional view taken along the line BB of FIG. 8 in a state where the polishing liquid is supplied to the inside of the metal pipe and the jig is rotated. It is a partially enlarged sectional view of the jig of FIG.

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

The inner surface polishing device 10 of the present embodiment shown in FIG. 1 polishes the inner surface of a long metal pipe (material to be polished) having a length of 4 m. Here, a case where the metal pipe is a stainless steel pipe will be illustrated. In this embodiment and the examples and comparative examples described later, the "stainless steel pipe" is a stainless steel pipe, a stainless steel tubular member, or a stainless steel tube. The stainless steel pipe whose inner surface has been polished by the inner surface polishing device 10 is used in a food or chemical manufacturing device, but its use is not particularly limited. The arithmetic mean roughness (Ra) of the inner surface of the stainless steel pipe polished by the inner surface polishing device 10 is less than 0.1 μm.

The inner surface polishing device 10 is not limited to stainless steel pipes, and can polish pipes made of metals other than stainless steel such as titanium and brass, tubular members, or the inner surface of tubes. Further, in the present embodiment, a long stainless steel pipe having a length of 4 m is polished, but the length of the metal pipe to be polished is not particularly limited. The inner surface of a metal pipe shorter than 4 m may be polished, while the inner surface of a metal pipe longer than 4 m, such as 6 m, may be polished.

As will be described later, the inner surface polishing device 10 polishes the inner surface of the stainless steel pipe using a wet abrasive mixed in the liquid. Therefore, in order to prevent the liquid from leaking to the outside, the inner surface polishing device 10 is covered with a box-shaped cover (not shown), but the cover is omitted here for convenience of explanation.

FIG. 6 shows a state in which the stainless steel pipe (metal pipe) 1 is arranged in the inner surface polishing device 10 shown in FIG. With reference to FIG. 6, the inner surface polishing device 10 is a pump (supply means) 12 (FIG. 6) which is a supply means for supplying the polishing liquid to the inside of the stainless steel pipe 1 in a state where the stainless steel pipe 1 is arranged and fixed. 6), a jig (rotating body) 21 (see FIG. 1) that is a rotating body that rotates inside the stainless steel pipe 1, and a motor (driving means) that is a driving means that drives the jig 21 to rotate around a shaft 23. ) 30 (see FIGS. 1 and 6).

As shown in FIG. 6, the pump 12 communicates with the tank 13 for storing the polishing liquid. The polishing liquid in the tank 13 is discharged from the tip 14 of the pump 12. With the stainless steel pipe 1 arranged in the inner surface polishing device 10, the tip 14 of the pump 12 is connected to the end opening of the stainless steel pipe 1 on the opposite side of the motor 30 via a pipe (not shown). While the stainless steel pipe 1 is arranged and operated in the inner surface polishing device 10, the pump 12 discharges and supplies the polishing liquid to the inside of the stainless steel pipe 1. The polishing liquid supplied to the stainless steel pipe 1 is discharged from the opening at the end of the stainless steel pipe 1 on the motor 30 side. The discharged polishing liquid flows to the collector 16 arranged below the stainless steel pipe 1 and the jig 21 (see FIG. 1), and is stored in the drain van 17. The collector 16 is integrally formed with a cover (not shown).

The polishing liquid is a mixed liquid of a liquid and a granular abrasive. In this embodiment, water is used as the liquid, but the present invention is not limited to this. The liquid may be, for example, acidic water or an organic solvent. Specifically, the liquid may be alcohol, oil, ethanol or nitric acid. The material of the liquid is not particularly limited as long as it is used for polishing metal by being mixed with an abrasive.

In this embodiment, aluminum oxide is used as the abrasive, but the present invention is not limited to this. As the abrasive, for example, a wet abrasive is used. The abrasive preferably has a higher specific gravity than water and a higher hardness than the metal to be polished. For example, carbides or oxides are adopted as such abrasives. Specifically, carbon or diamond may be used as the abrasive. The material of the abrasive is not particularly limited as long as it is used for polishing metal by being mixed with a liquid.

The inner surface of the stainless steel pipe 1 is polished by pressing the abrasive against the inner surface of the stainless steel pipe 1 by the jig 21 (see FIG. 1). The inner surface polishing device 10 of the present embodiment has eight jigs 21, and these jigs 21 are connected in the shaft 23 direction via a shaft 22. That is, the inner surface of the 4 m stainless steel pipe 1 (see FIG. 6) is polished using eight jigs 21. For convenience of explanation, in the following description, the eight jigs 21 and the shaft 22 are collectively referred to as a jig unit 20.

As shown in FIG. 1, one end of the jig unit 20 on the motor 30 side (one end of the shaft 22) is rotatably supported by the motor 30. The other end of the jig unit 20 opposite to the motor 30 (the other end of the shaft 22) is supported by a support leg 33c standing on the ground. In the jig unit 20, the shaft 22 portion is supported by a plurality of support legs (not shown) arranged at predetermined intervals between the motor 30 and the support legs 33c. The tip of the support leg 33c is supported by sandwiching the shaft 22, and the jig unit 20 can be supported and the support can be released by opening and closing the tip. When moving the stainless steel pipe 1 from the other end to one end of the jig unit 20 while covering the jig unit 20 with the stainless pipe 1, the support legs 33c release the support of the jig unit 20.

FIG. 2 is a partially enlarged top view showing three jigs 21 on the other end side of the jig unit 20 arranged apart from the motor 30. The jig unit 20 has eight jigs 21, but here, only three jigs 21 are shown as representatives. Each of the eight jigs 21 has the same shape, and the length dimension of the jig 21 is L1. Adjacent jigs 21 are arranged at equal intervals at intervals of L2. The distance L2 between the jig 21 and the jig 21 is shorter than the length L1 of the jig 21.

FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2, and is an enlarged cross-sectional view of the jig 21 in the direction orthogonal to the axis 23. The jig 21 is fixed to the shaft 22 and rotates together with the shaft 22. The jig 21 includes a main body 41 extending in the direction of the shaft 23, a brush 44 protruding from the main body 41 in the radial direction orthogonal to the shaft 23, provided on the outer side in the radial direction, and movable in the radial direction, and the shaft 23. It has a tube (inner elastic body) 45 which is an inner elastic body which is arranged between the brush 44 and elastically presses the brush 44 radially outward.

The main body 41 has a cylindrical cross section orthogonal to the shaft 23, and brush receivers 48 having three concave cross sections are integrally formed with the main body 41 at equal intervals in the circumferential direction of the main body 41. The base portion 44a of the brush 44 and the tube 45 are arranged inside the brush receiver 48. The brush 44 and the tube 45 are supported by the brush receiver 48.

The brush 44 is made of innumerable resins (hairs) that extend linearly and has elasticity. Here, the brush 44 is a concept including a base 44a in which innumerable resins are implanted. The individual resins constituting the brush 44 of the present embodiment have a circular cross section in the direction orthogonal to the extending direction. The diameter of each resin of the brush 44 (diameter of the surface perpendicular to the longitudinal direction) is not particularly limited as long as the brush 44 can maintain the upright state when the jig 21 inserted inside the stainless steel pipe 1 rotates. For example, a resin having a diameter (hereinafter referred to as a wire diameter) extending linearly of 0.2 mm or more and 0.6 mm or less may be adopted.

The brush 44 is supported by the side wall 48a of the brush receiver 48 so as to be movable in the radial direction. The brush 44 is arranged radially outward of the tube 45 and extends straight parallel to the shaft 23. In the present embodiment, the three brushes 44 are arranged at equal intervals in the circumferential direction of the main body 41. The number of brushes 44 is not limited to three. The brush 44 supported by the brush receiver 48 protrudes from the main body 41 in the direction (diameter direction) orthogonal to the axis 23, and stands up along the radial direction. The brush 44 is elastically pressed outward in the radial direction by the tube 45 and locked to a stopper (not shown) provided on the brush receiver 48 to maintain the support state by the brush receiver 48. To. The dimension L3 between the tip of the brush 44 and the shaft 23 is larger than the dimension L4 (see FIG. 4) which is half the inner diameter of the stainless steel pipe 1. The fact that the brush 44 and its tip stand up means that the brush 44 and its tip stand up, and does not include bending or bending of the brush 44 and its tip.

The inner elastic member is a resin tube 45, which has elasticity. The tube 45 is arranged in the brush receiver 48 between the shaft 23 and the brush 44, that is, radially inside the brush 44. The tube 45 arranged in the brush receiver 48 is arranged between the bottom wall 48b of the brush receiver 48 and the brush 44, and is elastically displaced. The tube 45 comes into contact with the brush 44 and presses the brush 44 directly outward in the radial direction. Further, since the tube 45 extends from one end to the other end of the brush 44 in the length direction of the brush 44 (direction parallel to the axis 23), the tube 45 uniformly spreads the brush 44 over the entire length direction of the brush 44. Can be pressed.

Returning to FIG. 1, the motor 30 moves the jig 21 along the shaft 23 while rotating the jig 21 around the shaft 23. The motor 30 is fixed on a substrate 32 movably installed on a pair of rails 31 in the direction of the shaft 23. The pair of rails 31 are arranged side by side in the horizontal direction, and are fixed to the support legs 33a standing on the ground and the support plates 34 attached to the support legs 33b.

Further, the substrate 32 is driven along the shaft 23 by a rack and pinion. A motor (not shown) is mounted on the substrate 32, and the motor rotates the pinion gear 37 via the shaft 36. The rotation of the support leg 33a and the pinion gear 37 that meshes with the rack gear 38 attached to the support leg 33b causes the motor 30 to move along the shaft 23 together with the substrate 32.

Hereinafter, a method of polishing the inner surface of the stainless steel pipe 1 with the inner surface polishing device 10 will be described.

FIG. 5 is a schematic cross-sectional view showing an inner surface polishing device 10 in the middle of installing the stainless steel pipe 1. In FIG. 5, the stainless steel pipe 1 is moved in the direction of the shaft 23 so as to cover the jig 21 from the other end to one end of the jig unit 20 (see FIG. 7) for positioning. FIG. 8 is a partially enlarged top view of the other end of the jig unit 20 showing a state in which the stainless steel pipe 1 is positioned. When the stainless steel pipe 1 is positioned and fixed, all the jigs 21 are arranged inside the stainless steel pipe 1. When the stainless steel pipe 1 is positioned, the end opening of the stainless steel pipe 1 opposite to the motor 30 is connected to the tip 14 (see FIG. 6) of the pump 12 via a pipe (not shown), and the inside of the tank 13 is polished. The liquid can be supplied to the inside of the stainless steel pipe 1.

As shown in FIG. 3, the dimension L3 between the tip of the brush 44 and the shaft 23 is larger than the dimension L4, which is half the inner diameter of the stainless steel pipe 1. Therefore, as shown in FIG. 9, when the jig 21 is inserted inside the stainless steel pipe 1, the brush 44 moves inward in the radial direction, and the tube 45 is compressed. As a result, the tube 45 elastically presses the brush 44 outward in the radial direction, so that the tip of the brush 44 abuts on the inner surface of the stainless steel pipe 1 while the brush 44 stands upright, and a constant internal pressure is applied. At this time, as shown in FIG. 10, at least a part of the tip of the brush 44 is in vertical contact with the inner surface of the stainless steel pipe 1. In the present embodiment, it is preferable that the internal pressure applied by the tip of the brush 44 to the inner surface of the stainless steel pipe 1 is 80 N or more. In the present embodiment, it is preferable that the internal pressure applied by the tip of the brush 44 to the inner surface of the stainless steel pipe 1 is 300 N or less. When the internal pressure is smaller than 80N, the force with which the tip of the brush 44 presses the abrasive against the inner surface of the stainless steel pipe 1 becomes weak, and polishing tends to be difficult. On the other hand, when the internal pressure is larger than 300 N, the brush 44 tends to bend and it is difficult to stand up.

When the polishing liquid is supplied from the tank 13 shown in FIG. 6 to the inside of the stainless steel pipe 1, the polishing liquid passes through the space S (see FIG. 11) formed between the inner surface of the stainless steel pipe 1 and the surface of the jig 21. The polishing liquid spreads from one end to the other end of the stainless steel pipe 1. In this state, when the motor 30 rotates the jig 21 around the shaft 23, the polishing liquid moves to the tip of the brush 44 by centrifugal force and collects. Then, the tip of the brush 44 presses the polishing liquid against the inner surface of the stainless steel pipe 1, so that the polishing agent 2 adheres to the inner surface of the stainless steel pipe 1. Further, since the tube 45 elastically presses the brush 44 outward in the radial direction, the brush 44 and its tip portion maintain an upright state while the jig 21 is rotating (see FIG. 12). In this way, the brush 44 rotates around the shaft 23 while applying the internal pressure to the stainless steel pipe 1 via the polishing agent 2, so that the polishing agent 2 adhering to the inner surface of the stainless steel pipe 1 goes around the inner surface of the stainless steel pipe 1. Polish in the direction.

As described above, in the present embodiment, when the jig 21 is inserted inside the stainless steel pipe 1, the tube 45 is elastically displaced (compressed) inward. The tube 45 elastically displaced inward presses the brush 44 elastically outward in the radial direction. As a result, the tube 45 abuts on the inner surface of the metal pipe and applies an internal pressure while the tip of the brush 44 pressed outward in the radial direction stands up. Then, when the polishing liquid is supplied into the stainless steel pipe 1 to rotate the jig 21, the tip of the brush 44 rotates while maintaining the upright state. At this time, the tip of the brush 44 presses the attached abrasive against the inner surface of the stainless steel pipe 1, so that the abrasive polishes the inner surface in the circumferential direction. That is, the present invention relates to an apparatus for polishing the inner surface of a metal pipe using only physical polishing.

The motor 30 moves the jig 21 along the shaft 23 while rotating the jig 21 around the shaft. Since the adjacent jigs 21 are arranged at equal intervals, the motor 30 moves the jigs 21 in the shaft 23 direction by the interval L2 between the jigs 21 and the jigs 21. As a result, the entire inner surface of the stainless steel pipe 1 is polished by the jig 21 and the abrasive 2. By arranging the adjacent jigs 21 and the jigs 21 at intervals L2 in this way, the jigs 21 are pivoted as compared with the case where one jig extending in the entire longitudinal direction of the stainless steel pipe 1 is used. The driving force for rotating around 23 can be suppressed, and the size and power consumption of the motor 30 can be reduced. Further, the reaction force received from the inner surface of the stainless steel pipe 1 can be suppressed, and the jig unit 20 can be prevented from being damaged.

[Characteristics of the inner surface polishing apparatus of this embodiment]
The inner surface polishing device 10 of the stainless steel pipe 1 of the present embodiment has the following features.

In the inner surface polishing apparatus 10 of the present embodiment, as shown in FIG. 3, the dimension between the shaft 23 of the jig 21 and the tip of the brush 44 is L4 or more, which is half the inner diameter of the stainless steel pipe 1, and the tube 45. It is elastically displaced. As a result, when the jig 21 is inserted inside the stainless steel pipe 1, the tube 45 elastically displaced inward presses the brush 44 outward in the radial direction. Then, while the tip of the brush 44 pressed outward in the radial direction stands up, it contacts the inner surface of the stainless steel pipe 1 and applies an internal pressure. Therefore, when the jig 21 arranged inside the stainless steel pipe 1 is rotated while the polishing liquid is supplied, the tip of the brush 44 presses the polishing liquid against the inner surface of the stainless steel pipe 1 and the inner surface of the stainless steel pipe 1 is pressed. Polishing agent can be attached to. While the brush 44 applies internal pressure to the stainless steel pipe 1 via the polishing agent, the jig 21 rotates around the shaft 23, so that the polishing agent 2 adhering to the inner surface of the stainless steel pipe 1 goes around the inner surface of the stainless steel pipe 1. Polish in the direction. Thereby, the stainless steel pipe 1 whose inner surface is mirror-finished can be formed.

In the inner surface polishing device 10 of the present embodiment, dust generated when polishing the inner surface of the stainless steel pipe 1 is mixed in the polishing liquid, so that it is possible to prevent the dust from scattering into the atmosphere. Further, the liquid can absorb the frictional heat generated by the polishing agent 2 polishing the inner surface of the stainless steel pipe 1 and can cool it. On the other hand, if the inner surface of the stainless steel pipe is polished with a file, it takes time and effort to replace the worn file with a new file. However, in the present invention, since the abrasive 2 polishes the inner surface of the stainless steel pipe 1, the jig 21 itself does not wear. Therefore, it is possible to shorten the polishing time because it is possible to save the trouble of exchanging with a new jig 21.

In the inner surface polishing apparatus 10 of the present embodiment, it is preferable that the tip portion of the brush 44 is in contact with the inner surface of the metal pipe while standing upright and an internal pressure of 80 N or more is applied. In the inner surface polishing apparatus 10 of the present embodiment, it is preferable to apply an internal pressure of 300 N or less. When the internal pressure is smaller than 80N, the force with which the tip of the brush 44 presses the abrasive against the inner surface of the stainless steel pipe 1 becomes weak, and it tends to be difficult to polish, but this can be suppressed. On the other hand, when the internal pressure is larger than 300 N, the brush 44 tends to bend and it is difficult to stand up, which can be suppressed.

In the inner surface polishing device 10 of the present embodiment, the tube 45 arranged between the shaft 23 and the brush 44 may extend in the length direction of the brush 44 (the direction parallel to the shaft 23). As a result, the tube 45 can uniformly press the brush 44 over the entire length direction of the brush 44.

In the inner surface polishing apparatus 10 of the present embodiment, since the plurality of brushes 44 are arranged at equal intervals in the circumferential direction of the main body, the tips of the plurality of brushes 44 abut on the inner surface of the stainless steel pipe 1 to make the internal pressure applied uniform. Can be.

In the inner surface polishing apparatus 10 of the present embodiment, when the jig 21 is arranged inside the stainless steel pipe 1, the tip end portion of the brush 44 abuts perpendicularly to the inner surface of the stainless steel pipe 1 is the tip end portion of the brush 44. Means that the internal pressure is applied by contacting the inner surface of the stainless steel pipe 1 while standing upright. In this state, the brush 44 applies internal pressure to the stainless steel pipe 1 via the polishing agent 2, and the jig 21 rotates around the shaft 23, so that the polishing agent 2 adhering to the inner surface of the stainless steel pipe 1 is removed from the stainless steel pipe. The inner surface of 1 is polished in the circumferential direction. Therefore, it is possible to form the stainless steel pipe 1 whose inner surface is mirror-finished.

In the inner surface polishing device 10 of the present embodiment, the polishing liquid is injected from one end to the other end of the stainless steel pipe 1 with the jig 21 arranged inside the stainless steel pipe 1. As shown in FIG. 11, since the space S is formed between the inner surface of the stainless steel pipe 1 and the surface of the jig 21, the polishing liquid injected into the stainless steel pipe 1 passes through the space S of the stainless steel pipe 1. It can be spread from one end to the other.

In the inner surface polishing device 10 of the present embodiment, as shown in FIG. 1, the motor 30 rotates the jig 21 around the shaft 23 and moves the jig 21 along the shaft 23. As a result, even if the stainless steel pipe 1 is longer than the jig 21, the entire inner surface thereof can be polished.

In the inner surface polishing device 10 of the present embodiment, the jig 21 is connected in the direction of the shaft 23 via the shaft 22. By connecting a plurality of jigs 21 according to the length of the metal pipe, even if the length is, for example, 4 m or more, the plurality of jigs 21 can apply the abrasive 2 to the metal pipe. It can be polished by pressing it against the inner surface.

<Example>
The inventors of the present application measured the arithmetic mean roughness (Ra) of the inner surface of the stainless steel pipe 1 polished by the inner surface polishing device 10 and compared it with the arithmetic mean roughness (Ra) of the inner surface of the conventional stainless steel pipe.

Table 1 shows, as a comparative example, a graph showing the arithmetic mean roughness (Ra) in the circumferential direction of the inner surface of a stainless steel pipe polished by conventional vertical polishing. In this vertical polishing, a total of 5 steps are used, using a file with a grain size of 90 in the first step, 120 in the second step, 140 in the third step, 240 in the fourth step, and 400 in the fifth step. The inner surface of the stainless steel pipe was polished with. The particle size of the file is based on the JIS standard "JIS R 6010 Regulations based on the particle size of abrasive materials for abrasive cloth". Among the plurality of stainless steel pipes polished by such vertical polishing, when the arithmetic mean roughness (Ra) in the circumferential direction is measured for any two pipes, the first pipe is 0.7576 μm and the second pipe is 0. It was .6103 μm.

Table 2 shows a graph in which the arithmetic mean roughness (Ra) in the circumferential direction of the inner surface of the stainless steel pipe 1 polished by the inner surface polishing device 10 according to the present invention was measured. In this polishing, a polishing liquid obtained by mixing water as a liquid and aluminum oxide as an abrasive was used. In the first step, the jig 21 was rotated at 300 rpm for 30 minutes using a brush 44 having a wire diameter of 0.5 mm. When the internal pressure of the brush 44 pressing against the inner surface of the stainless steel pipe 1 was measured in the first step at an arbitrary time, it was 120 N or more and 160 N or less. In the subsequent second step, the jig 21 was rotated at 300 rpm for 30 minutes using a brush 44 having a wire diameter of 0.4 mm. When the internal pressure of the brush 44 pressing against the inner surface of the stainless steel pipe 1 was measured in the second step at an arbitrary time, it was 160 N or more and 270 N or less. Among the plurality of stainless steel pipes polished by these two steps, when the arithmetic mean roughness (Ra) in the circumferential direction was measured for any two pipes, the first pipe was 0.093 μm and the second pipe was 0. It was 096 μm. From the above, it was found that the arithmetic mean roughness (Ra) of the inner surface of the stainless steel pipe 1 according to the present invention was less than 0.1 μm. The arithmetic mean roughness (Ra) is based on the provisions of JIS B0031 (1994).

Although the embodiments of the present invention have been described above based on the drawings, it should be considered that the specific configuration is not limited to these embodiments. The scope of the present invention is shown not only by the description of the above-described embodiment but also by the scope of claims, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

In the above embodiment, the inner surface of the stainless steel pipe 1 having a length of 4 m is polished with eight jigs 21, but the present invention is not limited to this. A single jig having the same length as the stainless steel pipe may be used. At this time, it is not necessary to move the motor 30 and the jig 21 in the direction of the shaft 23 (see FIG. 1 and the like). The number of jigs is not limited to eight, and a plurality of jigs such as two or three may be used.

Further, in the above-described embodiment, as shown in FIG. 2, the distance between two adjacent jigs 21 is L2, and this distance L2 is shorter than the length L1 of the jig 21, but is not limited to this. The interval L2 may be the same as the jig length L1 or longer than the jig length L1 as long as the motor 30 can be moved in the axial direction to polish the entire inner surface of the stainless steel pipe.

In the above embodiment, the dimension L3 (see FIG. 3) between the tip of the brush 44 and the shaft 23 is larger than, but not limited to, the dimension L4 (see FIG. 4), which is half the inner diameter of the stainless steel pipe 1. The dimensions L4 may be the same.

In the above embodiment, the inner elastic body arranged between the shaft 23 and the brush 44 is a tube 45 having elasticity (see FIG. 3), but the present invention is not limited to this. The inner elastic body may be, for example, a spring or rubber.

In the above embodiment, as shown in FIG. 3, the case where the base portion 44a of the brush 44 is arranged inside the brush receiver 48 is shown, but a part of the base portion 44a is arranged inside the brush receiver 48. At least a part of the base 44a and the plurality of resins (hairs) implanted in the base 44a may be arranged.

In the above embodiment, as shown in FIG. 3, the brush receiver 48 has a side wall 48a and a bottom wall 48b, but the configuration of the brush receiver can be changed.

In the above embodiment, as shown in FIG. 3, the base portion 44a of the brush 44 is arranged on the radial outer side of the tube 45, and the tube 45 directly presses the base portion 44a of the brush 44. However, other members may be arranged between the tube 45 and the brush 44.

In the above embodiment, as shown in FIG. 3, the brush 44 and the brush receivers 48 that support the brush 44 are arranged at three locations at equal intervals in the circumferential direction of the jig 21. However, the brush 44 and the brush receivers 48 that support the brush 44 may not be arranged at equal intervals in the circumferential direction of the jig 21. The brush 44 and the brush receiver 48 that supports the brush 44 may be arranged at one, two, or four or more locations in the circumferential direction of the jig 21. Further, the brush 44 and the tube 45 arranged inside the brush 44 in the radial direction may be continuously arranged in the entire circumferential direction of the jig 21.

1 Stainless steel pipe (abrasive material)
2 Abrasive 10 Inner surface polishing device 12 Pump (supply means)
21 Jig (rotating body)
22 Shaft 23 Shaft 30 Motor (Drive means)
41 Body 44 Brush 45 Tube (inner elastic body)
S space

Claims

An inner surface polishing device for metal pipes that polishes the inner surface of metal pipes that are to be polished.
A rotating body that extends in the axial direction and
A driving means for rotating the rotating body around the axis, and
A supply means for supplying an abrasive liquid in which a granular abrasive and a liquid are mixed to the inside of the metal pipe,
With
The rotating body
It has a brush having elasticity protruding in the radial direction orthogonal to the axis, and an inner elastic body arranged radially inward from the brush.
The dimension between the shaft and the tip of the brush is at least half the inner diameter of the metal pipe.
With the rotating body arranged inside the metal pipe, the inner elastic body presses the brush outward in the radial direction, so that the tip of the brush abuts on the inner surface of the metal pipe while standing upright. At the same time, by applying an internal pressure to the inner surface of the metal pipe, the polishing agent supplied from the supply means to the inner surface of the metal pipe adheres to the inner surface of the metal pipe, and the tip of the brush makes the metal pipe. An inner surface polishing device for a metal pipe, characterized in that the inner surface is polished by being pressed against the inner surface of the metal pipe.
In a state where the rotating body is arranged inside the metal pipe, the tip of the brush is in contact with the inner surface of the metal pipe while standing upright, and an internal pressure of 80 N or more is applied to the inner surface of the metal pipe. The device for polishing the inner surface of a metal pipe according to claim 1.
In a state where the rotating body is arranged inside the metal pipe, the tip of the brush is in contact with the inner surface of the metal pipe while standing upright, and an internal pressure of 300 N or less is applied to the inner surface of the metal pipe. The device for polishing the inner surface of a metal pipe according to claim 1 or 2.
The rotating body has a brush receiver that supports the brush and the inner elastic body arranged radially inside the brush.
The internal polishing device for a metal pipe according to any one of claims 1 to 3, wherein the brush receiver supports the brush so as to be movable in the radial direction.
The brush receiver has side walls arranged on both sides of the brush.
The inner surface polishing apparatus for a metal pipe according to claim 4, wherein the side wall supports the brush so as to be movable in the radial direction.
The rotating body has a main body extending in the axial direction of the rotating body.
The brush is arranged radially outside the body and
The internal polishing device for a metal pipe according to any one of claims 1 to 5, wherein the inner elastic body is arranged between the main body and the brush.
The brush is arranged along the axial direction of the rotating body, and the brush is arranged.
The inner surface polishing apparatus for a metal pipe according to claim 1, wherein the inner elastic body is arranged along the axial direction of the rotating body inside the brush in the radial direction.
The rotating body has a plurality of the brushes.
A plurality of the brushes are arranged apart from each other in the radial direction of the rotating body.
The inner surface polishing apparatus for a metal pipe according to any one of claims 1 to 7, wherein a space is formed between two brushes adjacent to each other in the radial direction of the rotating body.
The internal polishing device for a metal pipe according to any one of claims 1 to 8, wherein a plurality of the brushes are arranged at equal intervals in the circumferential direction of the rotating body.
The rotating body has a plurality of the brushes and a plurality of the brush receivers.
Each of the plurality of brush receivers supports each of the plurality of brushes,
The inner surface polishing apparatus for a metal pipe according to claim 4 or 5, wherein a plurality of the brushes and brush receivers supporting the brushes are arranged at equal intervals in the circumferential direction of the rotating body.
With the rotating body installed inside the metal pipe,
When the tip of the brush is in contact with the inner surface of the metal pipe, at least a part of the tip of the brush is perpendicular to the tangent at the contact point in contact with the inner surface of the metal pipe. The inner surface polishing apparatus for a metal pipe according to any one of claims 1 to 10.
The inner surface of the metal pipe according to any one of claims 1 to 11, wherein the driving means moves the rotating body along the axis while rotating the rotating body around the axis. Polishing equipment.
The internal polishing device for a metal pipe according to any one of claims 1 to 12, wherein a plurality of the rotating bodies are connected in the axial direction via a shaft.
The internal polishing device for a metal pipe according to claim 13, wherein the distance between the rotating bodies adjacent to each other in the axial direction is shorter than the axial length of the rotating bodies.
A claim characterized in that, in a state where the rotating body is installed inside the metal pipe, the inner elastic body is compressed, and the inner elastic body elastically presses the brush radially outward. Item 2. The metal pipe inner surface polishing apparatus according to any one of Items 1 to 14.
A metal pipe characterized in that the arithmetic average roughness (Ra) of the inner surface polished by the inner surface polishing apparatus according to any one of claims 1 to 15 is less than 0.1 μm.
A metal pipe characterized in that the inner surface is polished by the inner surface polishing apparatus according to any one of claims 1 to 16 and the length is 4 m or more.