JPH05337814A - Method of polishing inner surface of nonmagnetic pipe and inner surface polishing device - Google Patents

Abstract

PURPOSE:To provide a method and a device which can polish a branching part of a branching pipe and a curved part of a curved pipe in an inner surface polishing process for a nonmagnetic pipe. CONSTITUTION:A magnetic rotary plate 44 carrying at its outer surface magnets A, B is made to approach the outer periphery of a nonmagnetic pipe in one of directions. The nonmagnetic pipe 5 is fixed to a chuck 21 coupled to a rotary mechanism for rotating a branching pipe 5c without the latter making contact with the rotary disc 44. The magnetic disc 44 is located at an arbitrary position without interference with the branching pipe 5c so as to effect magnetic force even upon the inside of a branching part 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for polishing the inner surface of a non-magnetic pipe, and more particularly to a technique suitable for polishing the inner surface of a branched portion or a bent portion of a branched pipe or a curved pipe.

[0002]

2. Description of the Related Art As a conventional method for polishing a non-magnetic pipe, a polishing tool made of a magnetic material or a magnetic fluid is contained in the pipe,
There has been one that rotates a magnetic body by applying a magnetic field from a magnet or an electromagnetic coil arranged around the tube. The advantages of these polishing methods are that the mechanism can be polished by a magnetic action without contact with the drive mechanism, the mechanism is simple and easy to adjust, and only a specific portion in the tube can be polished.

[0003]

By the way, a non-magnetic tube may be a branch tube such as a T-shaped tube or a Y-shaped tube or an L-shaped tube, depending on the application.
Although there is a curved pipe such as a U-shaped pipe, it is almost impossible to polish the branched portion and the bent portion with the above-mentioned conventional magnetic polishing apparatus, and since a weld bead portion is formed in this portion. The polishing operation itself was extremely difficult. Therefore,
The inner surface of this portion was polished in a state where the pipe was cut in the vicinity of the branched portion and the bent portion, and thereafter, the pipe was welded at the straight pipe portion, and the inner surface of the welded portion was further polished.
Therefore, in view of the above problems, it is an object of the present invention to obtain a magnetic polishing method and apparatus capable of polishing the inner surface without trouble even at a branched portion or a bent portion of a pipe.

[0004]

Means for Solving the Problems The means taken by the present invention to achieve the above object is to provide a magnetic field rotating around a rotation axis substantially perpendicular to the axis of the non-magnetic tube in any of the surroundings of the non-magnetic tube. In addition, the non-magnetic tube is rotated relative to the magnetic field around its axis while being applied from the direction. In this case, it is desirable to provide a pre-stage polishing step using extended grains for the magnetic body and a post-polishing step using non-extended grains for the magnetic body. Further, as the polishing device, a magnetic field rotating plate having a plurality of magnetic poles arranged in any direction around the non-magnetic tube and having a plurality of magnetic poles facing the non-magnetic tube, and a rotary shaft substantially perpendicular to the axis of the non-magnetic tube. Magnetic field rotation drive means for substantially rotating the magnetic poles of the magnetic field rotary plate by means of a positioning mechanism for adjusting the positional relationship between the magnetic field rotary plate and the non-magnetic tube, and tube rotation for rotating the non-magnetic tube around its axis. And a mechanism. ..

[0005]

According to such means, the rotating magnetic field formed by the rotation of the magnet or the electromagnetic coil is applied from any direction around the non-magnetic tube by the axis of rotation substantially perpendicular to the axial direction of the non-magnetic tube. Therefore, it is not necessary to dispose the magnetic field generation member around the non-magnetic tube, and the branch portion and the bent portion can be polished similarly to the straight pipe portion. Here, in the first-stage polishing step, by using the extended-shaped grains as the magnetic material, the synchronization force with the rotating magnetic field is strengthened to increase the polishing rate, and in the second-stage polishing process, the non-extended-shaped grains are used to improve the polishing surface quality. Therefore, the polishing efficiency can be improved.

[0006]

Embodiments of the present invention will now be described with reference to the drawings. This embodiment is an example of a polishing device for realizing the polishing method and device according to the present invention. As shown in FIG. 1, one end 5a of the non-magnetic tube 5 arranged at the left end of the base 1 is gripped. And a tube drive part 2 for rotating the tube 1 and a tube which is movably mounted along guide frames 12 formed on both side surfaces of the base 1 and rotatably supports the other end 5b of the non-magnetic tube 5. The support portion 3 and the positioning portion 4 slidably mounted on the guide surface 11 of the base 1 are roughly configured.

The tube drive section 2 accommodates a chuck 21 for holding the one end 5a of the non-magnetic tube 5, a pulley 22 connected to the chuck 21, a drive belt 23, and a motor 24. The other end 5 of the non-magnetic tube 5 is attached to the tube support portion 3.
A chuck (not shown) for holding b is rotatably attached. The positioning portion 4 has a sliding table portion 41 slidably fitted on the guide surface 11, a lifting table 42 fitted to the sliding table 41, and a guide rail 42 a formed on the lifting table 42. And a drive table 43 that is slidably attached. As shown in FIG. 2, a gear 49 that meshes with a worm gear 50 directly connected to the operation handle 51 is housed inside the lifting table 42, and the gear 49 is a sliding table portion 41.
It is fixed to a ball screw 48 that is screwed into.

As shown in FIG. 2, a disk-shaped magnetic field rotating plate 44 is rotatably attached to the drive table 43, and a pulley 45, a drive belt 46, and a drive belt 46 fixed to a rotating shaft 44a of the magnetic field rotating plate 44 are provided. A motor 47 is housed. Magnets A and B are isotropically attached to the upper surface of the magnetic field rotating plate 44 along the rotation direction. The magnets A are arranged on the inner circumference side, and the magnets B are arranged on the outer circumference four by four so as to have opposite polarities alternately along the rotation direction, and each magnetic pole surface is formed so as to be slightly inclined inward. .. The number of these magnets, the number of rows, and the mutual angle are appropriately changed depending on the tube diameter of the non-magnetic tube 1 and the type of magnetic material housed inside.

In this magnetic polishing apparatus, as shown in FIG. 1, the non-magnetic tube 5 is chucked with the branch tube 5c facing upward so that the center of the magnetic rotary plate 44 is located immediately below the branch section 6. Then, the sliding table 41 and the drive table 43 are slid and adjusted. The distance between the magnetic rotary plate 44 and the branching portion 6 is adjusted by rotating the handle 51 shown in FIG. 2 to vertically move the lifting table 42.

The inner surface of the branch portion 6 is polished by rotating the magnetic rotary plate 44 and slowly rotating the non-magnetic tube 5 by the motor 24 within a range in which the branch tube 5c does not contact the drive table 43. Here, it is also possible to carry out polishing while reciprocating the non-magnetic tube 5 within the above range by a well-known mechanism or forward / reverse driving of a motor. In addition, the non-magnetic tube 5
Alternatively, polishing can be performed while reciprocating the drive table 43 in the axial direction. The magnetic body used in this device is a polishing tool consisting of an extended magnetic body or magnet that matches the curvature of the inner surface of the tube, a magnetic fluid mixed with abrasive grains such as diamond grains, or magnetic powder or the like. For example, a mixture of abrasive grains. An extended magnetic body or magnet has a large synchronization force with respect to the rotating magnetic field, which improves polishing efficiency.However, general magnetic fluids or powders that are not extended have a small synchronization force and are suitable for the finishing process. There is. In view of this, the present inventor efficiently performs polishing in the rough polishing by using the polishing tool or the extended shape (needle-shaped) magnetic powder (for example, 0.5 mm diameter, 3 to 5 mm length), and the final step. A general magnetic fluid or a non-extended magnetic powder is used as the material to achieve both polishing efficiency and the quality of the polished surface.

In this embodiment, although the non-magnetic tube 5 is a branch tube, the branch portion can be polished without any trouble. In addition, since the mechanism surrounding the non-magnetic pipe is not required and polishing can be done by arranging the mechanism only in a certain direction around it, it is easy to adjust the pipe diameter and pipe shape and has a wide range of application, making it suitable for branch pipes. Without being limited to this, various bending shapes can be applied to a curved tube such as an L-shaped tube or a U-shaped tube having a bent portion, and further, it can be adapted to a different diameter tube (reducer) with a simple mechanism. It goes without saying that there is an advantage that only the branched portion and the bent portion can be selectively polished without affecting other portions. In this method, the magnetic flux density in the non-magnetic tube tends to be smaller than in the case where a magnetic field is applied from the entire circumference of the tube, but the use of pre-stage polishing that uses extended magnetic powder reduces the polishing efficiency. Can be suppressed.

In the above apparatus, the magnetic poles of the magnets are arranged on the magnetic field rotation plate 44, and the rotating magnetic field is formed by rotating the magnetic poles. However, by using the magnetic field rotation plate in which the magnetic poles of the electromagnetic coil are arranged, The rotating magnetic field may be generated from a fixed magnetic field rotating plate. It is also possible to rotate the magnetic field rotating plate around the nonmagnetic tube instead of rotating the nonmagnetic tube. Further, in order to improve the polishing efficiency and the uniformity of polishing in the pipe, the entire positioning portion 4 is connected to a link mechanism,
It is also possible to reciprocate the nonmagnetic tube 5 in the axial direction with respect to the base 1 so as to reciprocate the magnetic tool, the magnetic powder and the like in the tube. Furthermore, by connecting the chuck 21 to the pulley 22 via a spline or the like, movably attaching the chuck 21 in the axial direction of the non-magnetic tube 5, and connecting an air vibrator, a piezoelectric vibrator, or the like,
It is also possible to superimpose high frequency vibration in the axial direction of the non-magnetic tube 5. In this case, it has been confirmed that the polishing efficiency is improved. Especially when using magnetic fluid or magnetic powder in which abrasive particles are mixed in the tube, dispersion and separation action of polishing scraps in the fluid or powder Therefore, the polishing characteristics can be maintained and the life of the polishing agent can be extended.

[0013]

As described above, according to the present invention, a rotating magnetic field having a rotation axis substantially perpendicular to the axial direction of the tube is applied from any direction around the non-magnetic tube, and the magnetic field is not applied to this magnetic field. Since the magnetic tube is characterized in that it is relatively rotated, the following effects are obtained. Similar to the straight pipe portion, magnetic polishing can be performed at a branch portion or a bent portion of a branch pipe or a curved pipe. The polishing efficiency can be improved by using the extended magnetic particles in the first step to secure the polishing rate and by using the non-extended magnetic particles in the second step to improve the quality of the polishing surface.

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of an inner surface polishing apparatus for a non-magnetic tube according to the present invention.

FIG. 2 is a vertical cross-sectional view showing the structure of a positioning unit in the same device.

[Explanation of symbols]

 1 base 2 pipe drive part 3 pipe support part 4 positioning part 44 magnetic rotating plate A, B magnet 5 non-magnetic pipe 6 branch part

Claims (3)

[Claims] 1. A method of polishing a inner surface of a non-magnetic tube by driving a magnetic body inside the tube by a magnetic field applied from the outside of the non-magnetic tube, wherein the magnetic field rotates about a rotation axis substantially perpendicular to the axis of the non-magnetic tube. Is applied from any direction around the non-magnetic tube, and the non-magnetic tube is relatively rotated around its axis with respect to the magnetic field. 2. The inner surface of a non-magnetic tube according to claim 1, further comprising a pre-polishing step in which extended magnetic particles are used for the magnetic body and a post-polishing step in which non-extended spherical particles are used for the magnetic body. Polishing method. 3. A device for polishing a inner surface of a non-magnetic tube by driving a magnetic material in the non-magnetic tube by a magnetic field applied from the outside of the non-magnetic tube, the non-magnetic tube being arranged in any direction around the non-magnetic tube. A magnetic field rotating plate having a plurality of magnetic poles facing the tube; a magnetic field rotation driving means for substantially rotating the magnetic poles of the magnetic field rotating plate on a rotation axis substantially perpendicular to the axis of the non-magnetic tube; An inner surface polishing apparatus for a non-magnetic tube, comprising: a positioning mechanism for adjusting a positional relationship with the magnetic tube; and a tube rotating mechanism for rotating the non-magnetic tube around its axis.