JPS6368356A - Polishing of inside surface of curved pipe and device thereof - Google Patents

Abstract

PURPOSE:To form a strong magnetic brush by connecting a plurality of curved pipes into ring form and charging the inside of the curved pipe with magnet pieces and magnetic polishing material and polishing the inside surface of the curved pipe by forming the magnetic field which crosses the curved pipe S. CONSTITUTION:Inside a work holder 11, a plurality of curved pipes W charged with magnet pieces 41 and magnetic polishing material 42 inside are connected in ring form and held, and when an exciting coil conducts, the magnetic fluxes which cross the curved pipes W are generated between the upper magnetic pole 24a and the lower magnetic pole 24b, and the magnetic polishing member 42 is adsorbed onto the outer surface of the magnet piece 41, and said magnet pieces 41 are oriented, and a magnetic brush is formed. When the curved pipe W held onto the work holder 11 by a supporting shaft 12 is revolution-driven in this state, the inside surface of the curved pipe shifts relatively to the magnetic brush, and polishing is performed uniformly and sufficiently. Therefore, a number of curved pipes can be polishing-finished in a short time.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention forms a magnetic brush that is oriented by a magnetic field, and polishes the inner surface of a curved pipe made of stainless steel or the like using the magnetic brush. This invention relates to a polishing method and device.

[Background of the invention]

BACKGROUND OF THE INVENTION In various types of equipment used in fields such as biotechnology, medicine, food, and the electronics industry, it is required to clean not only each part of the equipment but also the inside of the pipes through which processed materials pass. An important requirement for cleaning inside pipes is the finished state of the inner surface of the pipes. The inner surface of this type of piping needs to be finished to a nearly mirror-like finish so that the processed materials passing through it do not adhere to it.

Conventionally, belt polishing, puff polishing, lapping, and the like are frequently used as finishing methods for the inner surface of tubes. Many of these polishing methods are automated, and in the case of cylindrical containers, straight pipes, etc., the inner surface can be relatively efficiently polished by this polishing method.

[Problem that the invention seeks to solve]

On the other hand, due to the unique shape of bent pipes called elbow pipes, it is not possible to polish them sufficiently using the polishing method described above, and even if polishing is performed, the polishing quality of the inner surface is not uniform. There is a point. In particular, it is extremely difficult to polish the inner surface of a curved pipe with a relatively small diameter (eg, 40 mm or less) to a near-mirror surface using the above method.

Therefore, in order to polish the inner surface of small-diameter curved pipes, the seventh
The method shown in the figure is adopted. In this polishing method, a polishing brush l is used, which has a polishing body K made of plastic or the like fixed to the tip of a wire. This polishing brush 1 is inserted through the opening 2a of the curved tube 2 while rotating at high speed,
The polishing work is performed by sliding the polishing body K on the inner surface of the curved pipe 2.

However, in order to polish the entire inner surface of the curved pipe 2 in the polishing method shown in FIG. However, it becomes a two-step process, resulting in poor efficiency. Furthermore, if the inner surface of the curved tube 2 is polished from two directions, the central portion of the inner surface of the curved tube cannot be sufficiently polished, and the polishing quality of the inner surface tends to be uneven.

The present invention was made to solve the above-mentioned conventional problems, and it is possible to efficiently and quickly polish the inner surface of a curved pipe with a small diameter, and to improve the polishing quality of the entire inner surface. Can be done uniformly over the entire area. The present invention provides a method and apparatus for polishing the inner surface of a curved pipe.

[Specific means for solving the problem] The method of polishing the inner surface of a curved pipe according to the present invention involves filling the inside of a curved pipe made by joining a plurality of parts in a ring shape, and filling the inside of the curved pipe with magnet pieces and magnetic abrasive material. A magnetic field is formed across the tube, and the magnetic pieces with the magnetic abrasive material adsorbed on the surface are oriented along the magnetic field, and the curved tube and the magnetic field are moved relative to each other so that the magnetic abrasive material bends the curved tube. This polishes the inner surface of the

As the magnetic abrasive material, for example, a reaction product of aluminum oxide and iron mixed with iron powder is used, and as the magnet pieces, for example, finely cut rubber magnets are used.

According to the method of the present invention, the magnetic abrasive material filled in the inner surface of the curved tube is attached around the magnet pieces, and the magnet pieces are oriented by strong force along the magnetic field. Therefore, a magnetic polishing brush that is strongly held by the magnetic field is formed on the inner surface of the curved tube, and due to the relative movement between the curved tube and the magnetic field, the magnetic brush slides on the inner surface of the curved tube, making the inner surface almost mirror-like. It will be polished evenly.

Further, the polishing device for the inner surface of a curved pipe according to the present invention is provided with a work holder that holds a curved pipe in which a plurality of parts are joined in a ring shape, and magnetic poles facing each other with the curved pipe in between. is filled with abrasive material that is oriented by the magnetic poles, and is provided with a rotational drive member that rotates the work holder and the magnetic poles relative to each other.

This device allows the polishing method to be carried out automatically and at high speed. Further, by providing a plurality of sets of magnetic poles and work holders and rotating each work holder at the same time, a large number of curved pipes can be polished at the same time.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings of FIGS. 1 to 6.

1 is a longitudinal sectional view showing the entire polishing apparatus according to an embodiment of the present invention, FIG. 2 is a plan view of the polishing apparatus shown in FIG. 1, and FIG. 3 is a longitudinal sectional view of the polishing apparatus shown in FIG. FIG. 5 is an enlarged plan view of the work holder shown in FIG. 3. FIG.

First, the structure of the polishing device for the inner surface of a curved pipe will be explained.

In FIG. 1, members indicated by hatching are made of a non-magnetic material such as stainless steel, and members not indicated by hatching are made of a magnetic material.

In FIG. 1, reference numeral 11 is a work holder. This work holder 11 is fixed to the upper end of a support shaft 12 (made of non-magnetic material). The support shaft 12 extends above and below a magnetic shielding plate 13 (made of non-magnetic material), and is rotatably supported by bearings 21a and 21b provided on the magnetic shielding plate 13 and the pedestal 15. A pulley 14 is fixedly provided in the middle of the support portion of the support shaft 12 . Further, a motor 16 is provided on the lower surface of the pedestal 15, and a drive pulley 18 is fixed to a drive shaft 16a of the motor 16. Four belts 22 are hung around this drive pulley. As shown in FIG. 2, the work holders 11 are arranged at four locations on the stand 15, and each work holder 11 has a support shaft
Each of the four belts 22 is hooked onto a pulley 14 provided at 2. The motor 16 is powered by a belt 22
The signal is transmitted to the four work holders 11 shown in FIG. 2 via the four work holders 11, and each work holder 11 is driven to rotate in the same direction at the same time.

An excitation coil 19 wound around a core 23a is installed on the magnetic shielding plate 13. A disk-shaped upper yoke 23b is fixed to the upper end of the core 23a, and a disk-shaped lower yoke 23c is fixed between the lower end of the core 23a and the magnetic shielding plate 13. Core 23a and each yoke 23b, 2
3c are all made of magnetic material. An upper magnetic pole 24a is fixed to the lower surface of the edge of the upper yoke 23b, and a lower magnetic pole 24b is fixed to the upper surface of the edge of the lower yoke 23c. The upper magnetic pole 24a and the lower magnetic pole 24b are vertically opposed to each other with the work holder 11 in between. Further, as shown in FIG. 2, four sets of upper magnetic poles 24a and lower magnetic poles 24b are provided, each of which is disposed at a position sandwiching each of the four work holders 11. The upper magnetic pole 24a and the lower magnetic pole 24b preferably have a shape that can completely cover a portion of the curved pipe W held by the work holder 11 from above and below.For example, in the illustrated embodiment, the cross-sectional shape of each magnetic pole 24a and 24b is is fan-shaped. Upper magnetic pole 24a and lower magnetic pole 24b
Of course, the shape is not limited to a fan shape, but may also be a cylindrical shape or the like.

Further, in FIG. 1, reference numeral 25 denotes a magnetic shielding plate (made of a non-magnetic material) provided inside the upper magnetic pole 24a and the lower magnetic pole 24b.

Next, the structure of the work holder 11 and the work W will be described in detail.

As shown in FIG. 3, a flange 31 (made of non-magnetic material) is formed at the upper end of the support shaft 12, and a disc-shaped presser member 32 (made of non-magnetic material) is mounted on this 7 flange 31. It is fixed by Porto 33. A ring-shaped lower holder piece 34 is integrated around the flange 31, and an upper holder piece 35 is integrated around the presser member 32. Both holder pieces 34 and 35 are made of magnetic material. The lower holder piece 34 is formed with a holding groove 34a, and the upper holder piece 35 is formed with a holding groove 35a. The two retainers 134a and 35a face each other and extend in a ring shape centered on the support shaft 12.

The symbol W is a stainless steel bent pipe serving as a workpiece. This bent pipe W is called an elbow pipe, and has a diameter of 90
As shown in FIG. By joining Wa, the curved pipe W becomes a complete ring shape in the closed state.The curved pipe W joined in a ring shape is connected to the holding l11134a of the lower holder piece 34 and the upper holder piece. 35, and the port 33 is held by force.

This work holder 11 is configured according to various structures of the curved pipe W. For example, as shown in FIG. 5, when a joining flange Wb is provided around the opening Wa of the curved pipe W It is possible to provide the lower holder piece 34 and the upper holder piece 35 with grooves that fit the joint flange wb, so that the joint flange wb can be positioned and held by each holder piece 34, 35. It is also possible to construct a structure that can hold a curved pipe that is not provided with a joint flange, and furthermore, no matter how the curved pipes W are joined to each other, they can be joined in a ring shape. It is possible to retain it.

Next, a method of polishing the inner surface of a curved pipe using the above-mentioned apparatus will be explained.

When performing polishing work, a total of 16 curved pipes W are held in the device shown in Figure 0, in which bent pipes W joined in a ring shape are held in each work holder ll arranged at four locations. will be done.

As shown in FIGS. 3 and 5, the inside of the curved pipe W joined and held in a ring shape is filled with magnet pieces 41 and magnetic abrasive material 42 to constitute a magnetic brush. The magnet piece 41 is, for example, a rubber magnet cut into small pieces. In addition, magnetic 'NF polishing material 4
As for No. 2, for example, a reaction product of aluminum oxide and iron mixed with iron powder is used.

When the excitation coil 19 is energized, a magnetic field is formed that revolves around the core 23a, the upper yoke 23b, the upper magnetic pole 24&, the lower magnetic pole 24b, and the lower yoke 23c, as shown in FIG. The upper magnetic pole 24a and the lower magnetic pole 24 of the curved pipe W
The magnetic flux crosses the part sandwiched by b. In the portion sandwiched between the magnetic poles 24a and 24b, as shown in FIG.
1 is now covered with the magnetic abrasive material 42. The magnetic pieces 41 are oriented by the magnetic flux that crosses the inner part of the tube sandwiched between the magnetic poles 24a and 24b, and a magnetic brush is formed by the magnetic abrasive material 42. Since the magnet piece 41 is strongly oriented within the magnetic flux due to its own polarity, the magnetic abrasive material 42 attracted around it forms a highly dense and strongly held magnetic brush.

When the motor 16 is started in this state, each work holder 11 and the curved pipe W held by the work holder 11 are rotationally driven by the belt 22. The work holder 11 may be rotated continuously in the same direction, or may be rotated forward and reverse at regular cycles.
Since the inner surface of the curved tube W moves relative to this magnetic brush, the inner surface of the tube W is uniformly and sufficiently polished by the magnetic brush. .

4(A) and 4(B) show a modification of the structure of the holder pieces 34 and 35 of the work holder 11. FIG. As shown in FIG. 3, when the lower holder piece 34 and the upper holder piece 35 are entirely made of magnetic material, when the gap δ between both the holder pieces 34 and 35 is made small, the holder pieces 34 and 35 face each other. (the gear rough δ portions on both sides of the curved tube W), the magnetic flux may be short-circuited, and the density of the magnetic flux passing through the curved tube W may decrease. Fourth
The embodiment shown in FIG. 4A and FIG. 4B is effective when the gap δ between the holder pieces 34 and 35 becomes small. In the embodiment shown in both FIGS. A non-magnetic material 51 or 53 is integrated into the. Further, a non-magnetic material 52 or 54 is integrated on the lower opposing surface of the upper holder piece 35. By integrating the magnetic material in this way, the holder piece 34
This prevents a magnetic short circuit between the
The magnetic flux density inside the tube increases.

The magnet pieces 41 can now be strongly oriented.

Next, experimental results of the present invention will be explained.

The inner surface of a curved pipe according to the present invention was polished using the apparatus shown in FIGS. 1 to 3. The polished bent pipe W is made of stainless steel, has an outer diameter of 21.7 mm in cross section, and a wall thickness of 1.6 mm.
51111, the diameter of the center line of the tube when four pieces are joined is 7
The inside of the 8.2ts zero-bent tube W was filled with a magnetic abrasive material in which iron powder was mixed into a reaction product of aluminum oxide and iron. The average particle size of the magnetic abrasive is 80 l1 (minimum particle size 4
0 gm, maximum particle size 120 s), the magnetic abrasive is 5
0 g was used, and 5% by weight of vegetable oil was mixed in to give further viscosity. In addition, 50 g of a rubber magnet cut into approximately 5 m square pieces was placed in the single curved pipe W. magnetic coil 19
A magnetomotive force of 5,000 ampere turns was used, and a magnetic force of about 5,000 Gauss was applied inside the curved pipe W. The work holder 1 has a circumferential speed of 2ra at the center line of the curved pipe W.
The polishing work was performed for about 5 minutes by rotating at a rotation speed of /secC. As a result, the inner surface of the curved pipe W could be finished in a mirror-like state.

In the illustrated embodiment, the work holder 11 is rotated while the magnetic poles 24a and 24b are fixed.

On the contrary, the work holder 11 is fixed and the magnetic pole 24a is
24b along the curved pipe W, it is possible to perform the same polishing operation.

〔Effect of the invention〕

As described in H below, according to the present invention, the inner surface of the curved pipe is finished uniformly and in a mirror-like state. In particular, in the method according to the present invention, since the magnetic pieces are mixed with the magnetic abrasive material in the curved tube, the magnetic pieces are strongly oriented within the magnetic flux by their own polarity, and the magnetic abrasives are attracted around the magnet pieces. The material can be used to form a powerful magnetic brush. It also becomes possible to polish a large number of curved pipes in a short time.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing the entire polishing device for the inner surface of a curved pipe according to an embodiment of the present invention, FIG. 2 is a plan view of the polishing device shown in FIG. 1, and FIG. FIGS. 4(A) and 4(B) are enlarged sectional views showing a work holding part of another embodiment, and FIG. 5 is an enlarged view of the work holding part. FIG. 6 is an enlarged view showing the orientation of the magnet pieces and the magnetic abrasive material,
FIG. 7 is a plan view showing a conventional method of polishing the inner surface of a curved pipe. DESCRIPTION OF SYMBOLS 11... Work holder, 12... Support shaft of work holder, 16... Motor which rotates work holder, 1
9... Excitation coil, 24a... Upper magnetic pole, 24b.
...Lower magnetic pole, 41... Magnet piece, 42... Magnetic abrasive material, W... Bent tube, Wa... Opening of bent tube. Fig. 1 11...Wharf W.1-7゛
16...Kukuho 1 and γE Hyakki Kai Yue Loso-719
19,iyt*coil 24
a-# Sheet α1 Jaw 2xb...R part attack W...Tomari tongue 2 Fig. 11...Work claw lure 12...Wharf water 1 and gamma T frame M22-° belt 240.・
・Σ part - Pole Fig. 3 11... Work hole 9゛ 12...
Grilled side dish 34.35... Honruku" and -su
w,,,a tatami 41...magne-/l-M
42...Porcelain shoulder material procedure 10 official seal) October 20, 1985 Director-General of the Patent Office Black 1) Akio Akio Patent Application No. 212162 of 1985 2 Name of the invention Inner surface of curved pipe Polishing method and device 3 Person performing correction

Claims (5)

[Claims] (1) Magnet pieces and magnetic abrasive material are filled inside a curved pipe made by joining multiple pieces in a ring shape, and a magnetic field is created across the curved pipe to create a magnet piece with magnetic abrasive material adsorbed to the surface. A method for polishing the inner surface of a curved tube, the method comprising: aligning the inner surface of the curved tube along the magnetic field, and moving the curved tube and the magnetic field relatively to polish the inner surface of the curved tube with the magnetic abrasive material. (2) The method for polishing the inner surface of a curved pipe according to claim 1, wherein the magnetic abrasive material is a reaction product of aluminum oxide and iron mixed with iron powder. (3) The method for polishing the inner surface of a curved pipe according to claim 1, wherein the magnet pieces are finely cut rubber magnets. (4) A work holder that holds a curved tube in which a plurality of objects are joined in a ring shape, and magnetic poles facing each other with the curved tube in between are provided, and an abrasive material oriented by the magnetic poles is provided inside the curved tube. A polishing device for the inner surface of a curved tube, which is filled with a rotating drive member that rotates a work holder and a magnetic pole relative to each other. (5) A plurality of magnetic poles are provided around the magnetic coil, and a plurality of work holders are provided in accordance with the number of magnetic poles, and each work holder is driven by a common rotational drive member. A polishing device for the inner surface of a curved pipe according to scope 4.