JPH05245747A - Internal grinding method and device thereof - Google Patents

Abstract

PURPOSE:To provide an internal grinding method and its device that is able to grind the internal surface of a workpiece and, what is more, no restriction of tools available. CONSTITUTION:A method of grinding an inner surface of a workpiece 10 with a circular inner surface 11 is as follows; a tool 1 4 solidified with a rotor 12 is set up in an interspace partitioned by an inner surface 11, making it contact with this inner surface 11, and a magnetic field generating part 18, forming an electric motor in cooperation with the rotor 12 is set up in the inner surface 11 so as to surround the workpiece 10, and then the rotor 12 is rotated by the magnetic field generating part 18, rotating the tool 14 as well, thus the inner surface is ground.

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 work piece having a circular inner surface.

[0002]

2. Description of the Related Art A polishing tool made of a magnetic material is placed in a space defined by the inner surface of a workpiece having a circular inner surface such as a pipe, and the polishing is performed by a magnetic field rotating around the workpiece. It has been proposed to rotate the tool for polishing and polish the inner surface of the workpiece (Journal of Precision Engineering, Vol. 55, No. 10, pp. 148-153).

[0003]

According to the above-mentioned polishing method,
The inner surface of the work piece can be polished. On the other hand, since the polishing tool itself must be magnetic, its application is limited.

It is an object of the present invention to provide an inner surface polishing method and a polishing apparatus capable of polishing the inner surface of a work piece without any limitation of tools used.

[0005]

The present invention is a method for polishing the inner surface of a workpiece having a circular inner surface. In this polishing method, a tool integrated with a rotor is arranged in a space defined by the inner surface and brought into contact with the inner surface, and a magnetic field generating portion which forms a motor together with the rotor surrounds the workpiece. And rotating the rotor by the magnetic field generator to rotate the tool and polish the inner surface.

When a current is applied to the magnetic field generator, a magnetic field is generated and the rotor rotates. The tool is rotated by the rotation of the rotor to polish the inner surface of the workpiece.

Since the rotor and the tool are provided independently of each other and the rotor plays the role of rotation, the tool formed of an arbitrary material can be used. This makes it possible to select a tool suitable for the property of the work piece. Further, when the rotor rotates, it is sufficient for the tool to contact the inner surface, and it is not necessary for the rotor to contact the inner surface, so that the rotor does not wear.

When carrying out the inner surface polishing, it is preferable to apply a load to the tool to bring it into contact with the inner surface.

As a result, uniform inner surface polishing can be efficiently performed.

The present invention is also an apparatus for polishing the inner surface of a workpiece having a circular inner surface. This apparatus includes a rotor rotatably arranged in a space defined by the inner surface, a tool that is non-rotatably attached to the rotor, is in contact with the inner surface, and rotates with the rotor, and the workpiece. A magnetic field generation unit is provided so as to surround the rotor and forms a motor together with the rotor.

A tool is attached to the rotor, both tools are arranged in a space defined by the inner surface of the workpiece, and are positioned radially inward of the magnetic field generating portion. After that, when an electric current is applied to the magnetic field generator, the rotor rotates and the tool polishes the inner surface.

Since the outer diameters of the rotor and the tool can be arbitrarily set, there is substantially no restriction on the diameter of the workpiece. Therefore, it is possible to polish a workpiece having a large diameter to a workpiece having a small diameter.

The tool is preferably formed so as to be pressed toward the inner surface.

By pressing the tool against the inner surface of the work piece with a predetermined load, a predetermined amount of polishing can be efficiently performed.

The rotor is rotatably supported by a rod penetrating the rotor and a pair of support members arranged to sandwich the rotor and support the rod, or sandwich the rotor. It is rotatably supported by two tools arranged at.

According to the former, since the rotor is supported by the dedicated rod and the supporting member, the rotor can be reliably supported, and the tool can be arranged only on one side of the rotor. According to the latter, a dedicated rod and a supporting member can be omitted.

[0017]

EXAMPLE As shown in FIGS. 1 and 2, the polishing method according to the present invention is to polish an inner surface 11 of a workpiece 10 having an inner surface having a circular cross-sectional shape. Workpiece 1
0 is formed of a non-magnetic material such as stainless steel.

First, the tool 14 integrated with the rotor 12 is placed in the space defined by the inner surface 11 and brought into contact with the inner surface 11. At this time, it is preferable that the tool 14 is pushed outward by, for example, a spring 16 and brought into contact with the inner surface 11 in a state where a load is applied to the tool 14.

After arranging the rotor 12 and the tool 14 at predetermined positions, the magnetic field generating portion 18 forming the electric motor together with the rotor 12 is arranged so as to surround the workpiece 10.
In this case, the magnetic field generation unit 18 surrounds the workpiece 10 in the circumferential direction at the outer side in the radial direction.

Then, the magnetic field generator 18 is energized to rotate the rotor 12 to rotate the tool 14 and polish the inner surface 11.

The apparatus of the present invention is an apparatus for polishing the inner surface 11 of a workpiece 10 having a circular inner surface 11, and includes a rotor 12, a tool 14, and a magnetic field generator 18.

The rotor 12 is rotatably arranged in the space defined by the inner surface 11 of the workpiece 10. Rotor 12
Can have the same structure as that used in the electric motor. Therefore, as shown in FIG. 4, a block-shaped core 12a made of mild steel (a), a can type (b) in which copper 13c is fitted into a silicon steel plate 12b having a notch on the outer periphery (b), a permanent magnet 12d is formed. 12e provided permanent magnet type (c), mild steel 12f with cylindrical permanent magnet 12g attached hysteresis type (d), mild steel 12h elongated elongated mild steel type (e), notch on outer periphery One such as a short-circuit winding type (f) in which the coil 12j is wound on the silicon steel plate 12i that is included can be selected.

The tool 14 is non-rotatably attached to the rotor 12 and comes into contact with the inner surface 11 of the workpiece 10, so that the rotor 1
Rotate with 2.

In the embodiment shown in FIG. 2, the tools 14 are formed in an arc shape, and three tools 14 are circumferentially arranged on each side of the rotor 12. The tool 14 is made of an abrasive material such as cloth or grindstone.

In the embodiment shown in FIGS. 1, 2 and 5a, a backup 15 is applied to the tool 14 and the tool 14
On the other hand, a cylindrical mounting portion 20 is projected from the rotor 12 to both sides, and three cylindrical arms 21 are mounted on each mounting portion 20 so as to be movable in the radial direction. The backup 15 is fixed to the arm 21 at its center.
The tool 14 is loaded by the coil spring 16 arranged between the mounting portion 20 and the backup 15, and the inner surface 11
Is pressed against.

Another means of pressing the tool 14 toward the inner surface 11 can be formed as shown in FIG. That is, the weight 22 is attached to the backup 15 and the arm 21 that support the tool 14 to increase the weight, and the tool 14 is pressed against the inner surface 11 by utilizing the centrifugal force generated by the rotation of the rotor (b). Or backup 15 and arm 21
Instead of installing a weight 22 on and, a backup 15
The movable wing 24 is attached to and the tool 14 is pressed against the inner surface 11 by the buoyancy of the air flow applied to the movable wing 24 (c).

In the embodiment shown in FIG. 1, the rotor 12 has a rod 26 penetrating the rotor 12 and a pair of support members 28 arranged to sandwich the rotor 12 and support the rod 26.
It is rotatably supported by and. The rod 26 is non-rotatably coupled to the mounting portion 20 of the rotor 12 in a state in which it is prevented from coming off, while the rod 26 and the support member 28 are rotatably coupled via a bearing (not shown),
Further, an O-ring 30 is arranged on the outer periphery of the support member 28. In the illustrated embodiment, the workpiece 1 is
When 0 is rotated, the O-ring 30 smoothly performs this rotation and also rotates the rotor 12 within the workpiece 10.

As shown in FIG. 6, a pair of retainers 34 are attached to a rod 26 connected to the rotor, and a cylindrical iron core 36 is movably attached inside each retainer 34, and three or more retainers 34 are attached. The balls 38 are arranged between the pair of iron cores 36. A ball groove 37 is provided in an outer peripheral portion of the iron core 36 facing the ball 38 to position the ball 38, and the coil 40 is arranged so as to surround the workpiece 10. When a direct current is applied to the coil 40, the pair of iron cores 36 attract each other and press the balls 38 toward the inner surface 11 of the workpiece 10. This makes it possible to cope with the rotation of the workpiece 10 and the rotation of the rotor.

According to the embodiment shown in FIG. 6, the pair of iron cores 3
By changing the distance between 6 or the ball 38
The inner surface 11 of the workpiece 10 by changing the size of the
Can handle differences in caliber. Further, the circulation of the slurry can be effectively performed.

Instead of supporting the rotor 12 by the pair of supporting members 28, the rotor 12 can be rotatably supported by the tool 14 itself. That is, as shown in FIG. 1, tools 14 are arranged on both sides of the rotor 12 and the rotor 12 is rotatably supported only by these tools 14. In this case, the pair of support members 28 can be omitted.

The magnetic field generator 18 is arranged so as to surround the workpiece 10 and forms a motor together with the rotor 12. In the embodiment shown in FIGS. 1 to 3, the magnetic field generator 18 includes an annular yoke 42 made of a magnetic material and a yoke 42.
6 electromagnets 4 arranged at equal intervals in the circumferential direction
And 4 are formed. The yoke 42 is attached to the frame 48 by a plurality of brackets 46 so that its central axis extends substantially horizontally.

The electromagnet 44 is obtained by winding a coil 52 around an iron core 50. Each of the iron cores 50 is attached to the yoke 42 in the radial direction by a coupling portion 54 provided on the yoke 42 at a distance from the yoke 42 in the axial direction. The tip surfaces of the plurality of iron cores 50, that is, the pole surfaces jointly define a space for receiving the non-workpiece 10 therein.

The yoke 42, the electromagnet 44, and the rotor 12
And form a motor, similar to a conventional motor. This electric motor may be either an induction type or a synchronous type, and three-phase alternating current or single-phase alternating current is used.

On the frame 48, as shown in FIG. 7, a long work piece 10 is supported, the work piece 10 is moved in the axial direction, and is further rotated around the axis line. Are arranged. As in this example,
If the workpiece 10 is rotated, the polishing rate can be increased.

The drive mechanism 60 comprises a slider 62 which is movable in a direction parallel to the central axis of the yoke.
Is supported by a rail assembly 64 fixed to the frame 48. The rail assembly 64 has a pair of rails 66 supported by a pair of brackets 68 fixed to the frame 48. The slider 66 is movably supported by the pair of rails 66.

The chuck 70 that holds the workpiece 10 is
The sliders 62 are arranged on a pair of supporting portions 72 extending upward in parallel with each other, and are rotatably supported by bearings (not shown). The chuck 70 has a pulley 78, and is rotated by a belt 80 stretched between the chuck 70 and a pulley 76 attached to a shaft of an electric motor 74 arranged on a slider 62.

The cam 84 is coupled to the shaft of the electric motor 82 arranged on the frame 48, and the crank 86 is connected to the cam 8
4 and a slider 62 are swingably connected. Therefore, the cam 62 moves the slider 62 and the belt 80 rotates the chuck 70.

The end portion of the rod 26 extending from the rotor is rotatably attached to the holding plate 90 in a state where it is prevented from coming off, and the holding plate 90 is fixed to the frame 48. This prevents the rotor from moving together with the workpiece 10 and positions the rotor inside the magnetic field generator 18.

Coil 52 of electromagnet 44 of magnetic field generator 18
In order to generate a rotating magnetic field from the magnetic pole surface of the iron core 50,
For example, supply three-phase alternating current. A rotating magnetic field is generated, the rotor 12 rotates with the movement, and the tool 14 polishes the inner surface. At the same time, the workpiece 10 is rotated in the direction opposite to the rotation direction of the rotor 12, and the slider 62 is moved in the axial direction.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of an embodiment of an inner surface polishing apparatus according to the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a front view showing a magnetic field generator.

FIG. 4 is a front view showing a model of a rotor.

FIG. 5 is a front view showing a means for pressing the tool against the inner surface of the workpiece.

FIG. 6 is a side view showing a portion that rotatably supports a rotor.

FIG. 7 is a perspective view showing a mechanism for rotating a workpiece and simultaneously moving the workpiece in the axial direction.

[Explanation of symbols]

 10 Workpiece 11 Inner Surface 12 Rotor 14 Tool 18 Magnetic Field Generation Part 26 Rod 28 Support Member

Claims (6)

[Claims] 1. A method of polishing the inner surface of a workpiece having a circular inner surface, wherein a tool integrated with a rotor is placed in a space defined by the inner surface to contact the inner surface, A magnetic field generating section that forms an electric motor in combination with the rotor is arranged so as to surround the workpiece, and the rotor is rotated by the magnetic field generating section to rotate the tool and polish the inner surface. Polishing method. 2. The inner surface polishing method according to claim 1, wherein a load is applied to the tool to bring it into contact with the inner surface. 3. An apparatus for polishing the inner surface of a workpiece having a circular inner surface, the rotor being rotatably disposed in a space defined by the inner surface, and non-rotatably attached to the rotor. And a tool that contacts the inner surface and rotates with the rotor, and is arranged so as to surround the workpiece,
An inner surface polishing apparatus comprising: a magnetic field generation unit that forms an electric motor together with the rotor. 4. The inner surface polishing apparatus according to claim 3, wherein the tool is formed so as to be pressed toward the inner surface. 5. The rotor according to claim 3, wherein the rotor is rotatably supported by a rod that penetrates the rotor and a pair of support members that are arranged to sandwich the rotor and that support the rod. Inner surface polishing equipment. 6. The inner surface polishing apparatus according to claim 3, wherein the tool is composed of two pieces arranged to sandwich the rotor, and the rotor is rotatably supported by the two tools.