JP2515177B2 - Magnetic polishing machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a circular inner surface of a workpiece such as a pipe for rotating a tool disposed in a space defined by the inner surface in the workpiece by a magnetic field. The present invention relates to a magnetic polishing device for polishing.

[0002]

2. Description of the Related Art A magnetic tool for polishing is arranged in a non-magnetic workpiece having a circular inner surface, that is, a surface to be polished, and the workpiece is subjected to a magnetic field rotating around the axis of the workpiece. A magnetic polishing apparatus for rotating the inside of the machine and polishing the surface to be polished is disclosed in Precision Engineering Society, Vol. 55, No. 10, 148-.
Pp. 153 and JP-A-62-102969.

In this type of magnetic polishing apparatus, the means for generating a magnetic field for rotating the tool comprises a plurality of electromagnets each having a coil wound around an iron core. The electromagnets are arranged at equal angular intervals around the axis of the workpiece so that the iron core extends radially with respect to the axis of the workpiece and the end face of the iron core, that is, the magnetic pole surface is on the side of the axis of the workpiece. There is. The work piece is arranged so as to pass through the space defined inside by the magnetic pole surface.

When an alternating current such as a three-phase alternating current is supplied to the coil of the electromagnet, the polarity of the electromagnet changes sequentially, so that the magnetic field generated by the magnetic field generating means is rotated around the workpiece. As a result, the tool is rotated around the axis of the work piece while being in contact with the work surface, so that the work surface is polished.

However, in the conventional magnetic polishing apparatus, since the position of the magnetic pole surface of the electromagnet in the radial direction of the inner surface to be polished is fixed, the work piece having a size that cannot pass through the space defined by the magnetic pole surface. Can not be polished. In addition, a work piece that is significantly smaller than the space defined by the pole faces has a small magnetic flux that reaches the work piece even if it can be polished, so the tool presses it against the inner surface of the work piece. The force applied is small and the polishing efficiency is extremely low.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic polishing apparatus capable of efficiently polishing various kinds of work pieces having different sizes.

[0007]

A magnetic polishing apparatus of the present invention is a magnetic polishing apparatus, wherein a tool arranged in a space defined by a circular inner surface of a workpiece is in contact with the inner surface of the workpiece. It includes magnetic field generating means for generating a magnetic field that rotates about an axis. The magnetic field generating means is a plurality of electromagnets in which a coil is wound around an iron core, and the plurality of magnetic magnets are arranged such that the iron core extends in a radial direction of the inner surface and the magnetic pole surface of the iron core is on the side of the axis of the workpiece. Of the electromagnet and a support mechanism that supports the electromagnet so that the position of the magnetic pole surface in the radial direction can be changed.

Prior to polishing, the electromagnets receive the workpiece within the space defined by their pole faces,
It is moved in the radial direction of the inner surface to be polished and releasably maintained at a position where the magnetic pole surface is slightly separated from the outer peripheral surface of the workpiece.

In this state, alternating current such as three-phase alternating current is supplied to the electromagnet. As a result, the magnetic field generated by the magnetic field generating means is rotated around the axis of the workpiece, so that the tool placed inside the workpiece is attracted toward the magnetic pole surface and pressed against the surface to be polished. And is rotated about the axis of the work piece.

According to the present invention, since the electromagnet is supported by the support mechanism so that the position of the magnetic pole surface in the radial direction of the inner surface to be polished can be changed, regardless of the size of the workpiece.
The magnetic pole surface can be set at a position slightly separated from the outer peripheral surface of the workpiece, and as a result, the magnetic flux generated from the magnetic field generating means effectively acts on the tool arranged in the workpiece, Therefore, various kinds of workpieces having different sizes can be efficiently polished.

The electromagnet can be supported by the support mechanism so that the entire electromagnet can move in the radial direction. In this case, it is preferable that the coil is wound in a truncated pyramid shape or a truncated cone shape so that the side of the magnetic pole surface is smaller than the side opposite to the side. This reduces the size of the space defined by the magnetic pole faces when the electromagnets are moved to a position where adjacent electromagnets come into contact with each other.

The coil is supported by the supporting means so as not to move in the radial direction, the iron core is supported by the supporting means such that the position of the magnetic pole surface in the radial direction is variable, and the coil is moved in the radial direction. It can be movably penetrated.

The support mechanism is provided for each of the electromagnets and is connected to the iron core of the corresponding electromagnet, and extends in the radial direction with a threaded rod and around the corresponding threaded rod screwed with the threaded rod. A plurality of first bevel gears rotatably supported by the support, and a second bevel gear that meshes with the first bevel gear, the first bevel gear being rotatably supported by the support about the axis; A second bevel gear and a rotating mechanism that rotates the second bevel gear can be provided.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a magnetic polishing apparatus 10 includes a box-shaped frame 12 which houses a power supply for the magnetic polishing apparatus.

The frame 12 can be moved to an arbitrary position on the floor by using a plurality of casters 14 attached to the lower surface thereof, and can be releasably installed at that position. A magnetic field generator 16 that generates a rotating magnetic field is mounted on the frame 12.

As shown in FIGS. 2 and 3, the magnetic field generator 16 includes an annular support 18 made of a magnetic material and a support 1.
8 and a plurality of electromagnets 20 arranged at equal angular intervals, and the frame 12 is provided by a plurality of brackets 22 so that the axis of the support 18 extends substantially horizontally.
Attached to.

The support 18 has flange portions 18b and 18c at both ends of a cylindrical main body portion 18a. The main body portion 18a has a first bevel gear 2 whose outer peripheral surface extends continuously.
4 is rotatably supported around the main body portion 18a.

The first bevel gear 24 is normally or reversely rotated about the axis of the support 18 by the forward or reverse rotation of a small gear 28 with which a large gear 26 attached thereto meshes with the large gear 26. . The small gear 28 is the flange portion 1 of the support 18.
It is attached to a shaft 30 rotatably supported by 8b and 18c, and is rotated by a handle 32 attached to the shaft 30.

Instead of directly supporting the first bevel gear 26 on the main body portion 18a, a plurality of small gears 28 meshing with the large gear 26 may be provided and supported by the joint action of the small gears. In this case, each pinion 28 has a flange portion 18b,
18c is attached to the shaft 30 rotatably supported, and the handle 32 is attached to any one of the shafts 30.

As shown in FIGS. 2, 3 and 4, the first bevel gear 24 has a second bevel gear 3 provided for each electromagnet 20.
4 is meshed. Each second bevel gear 34 is supported by a bracket 36 on a support 18 so as to be rotatable about an axis extending in the radial direction thereof.

As shown in FIG. 4, each second bevel gear 34
Has a screw hole that penetrates the second bevel gear in its axial direction. A screw rod 38 extending in the radial direction of the support 18 is screwed into the screw hole by a plurality of balls 40. Each screw rod 38 is not rotatable about its axis, but is movable in the longitudinal direction of the screw rod 38 so that the bracket 3
It penetrates through 6.

As shown in FIG. 5, each electromagnet 20 includes an iron core 42 having a quadrangular (or circular) cross-sectional shape,
A bobbin 44 made of an electrically insulating material, through which the iron core immovably penetrates in its longitudinal direction, and a truncated pyramid shape (or a truncated cone shape)
And a coil 46 wound around the bobbin 44. Each iron core 42 is connected to the tip portion of the screw rod 38 by a connector 48 so as to extend in the radial direction of the support 18.

The support 18, gears 28, 28, bracket 36, screw rod 38, ball 40 and connector 48 are
Made of magnetic material. Therefore, the iron core 42 of the electromagnet 20
Are magnetically connected to each other.

The electromagnets 20 are arranged such that the tip end surface of the iron core 42, that is, the magnetic pole surface 50 is on the side of the axis of the support 18. The magnetic pole surface 50 has a work piece 32 on its inner side.
Jointly define the space to receive. The work piece 52 has an inner surface with a circular cross section like a pipe,
It is also made of a non-magnetic material such as stainless steel.

In the example shown in FIG. 2, six electromagnets shown by solid lines are used. However, when polishing a workpiece having a large diameter, the electromagnet 20, the screw rod 38, and the pinion gear 34 may be further arranged at the position indicated by the chain double-dashed line in FIG.

On the frame 12, a drive mechanism 54 for holding a long work piece 52, moving the work piece in its axial direction, and rotating the work piece 52 about its axis. Are arranged.

As shown in FIG. 6, the drive mechanism 54 includes a slider 5 which is movable in a direction parallel to the central axis of the support 18.
6 is provided. The slider 56 is supported by a rail assembly 58 fixed to the frame 12.

In the illustrated example, the rail assembly 58 supports a pair of rails 60 extending parallel to each other and the central axis of the support 18 on a pair of brackets 62 fixed to the frame 12, and also a slider 56. The rail 60
I support it.

The chuck 64 that holds the workpiece 52 is
The workpieces 52 are arranged on a pair of supporting members 66 extending upward from the slider 56 in parallel with each other, and by a bearing (not shown) attached to the supporting members 66.
It is rotatably supported around the axis of.

As shown in FIG. 6, a moving mechanism 68 for moving the workpiece 52 in its axial direction includes a rotation source 70 including an electric motor and a speed reducer, a cam disc 72 attached to the rotation shaft, A crankshaft 74 for converting the rotational movement of the cam disc 72 into a reciprocating movement in the axial direction of the workpiece.
With.

One end of the crankshaft 74 is connected to the outer peripheral edge of the cam disk 72, and the other end is connected to the slider 56 via a bracket 76. Therefore, the slider 56 is reciprocally moved in the axial direction of the workpiece 52 by the rotation of the rotation source 70, whereby the chuck 6 is moved.
4 is also reciprocated in the same direction.

As shown in FIG. 6, the rotating mechanism 78 for rotating the work piece 52 around its axis is a rotation source 80 including an electric motor and a speed reducer, a pulley 82 attached to the rotation shaft, and a chuck. A pulley 84 attached to the outer peripheral surface of the reference numeral 64 and an endless belt 86 wound around the pulleys 82, 84 are provided, and the chuck 64 is rotated around the axis of the workpiece 52 by the rotation of the rotation source 80. Let

Prior to polishing, the workpiece 52 is grasped by the chuck 64 so as to extend through the chuck 64 and the space defined by the magnetic pole surface 50 of the iron core 24 and be slightly inclined with respect to the horizontal line. To be done. This allows
The work piece 52 is arranged such that the axis of the electromagnet 20 extends in the radial direction of the inner surface of the work piece 52.

At this time, the position of the electromagnet 20 in the radial direction of the support 18 and the workpiece 52 can be corrected by rotating the handle 32 in the normal direction or the reverse direction.

That is, when the handle 32 is normally rotated,
Small gear 28, large gear 26, first and second bevel gears 2
Since the screws 4, 38 are rotated in the normal direction, the screw rod 38 is moved inward in the radial direction of the support 18, while the handle 32 is rotated in the reverse direction, the small gear 28, the large gear 26, the first and second gears.
Since the bevel gears 24 and 34 are reversed, the screw rod 38 is moved outward in the radial direction of the support 18.

Therefore, the position of the magnetic pole surface 50 in the radial direction of the support 18 can be adjusted according to the outer diameter of the workpiece 52. Each electromagnet 20 can be moved to the position shown by the dotted line in FIG. 2, for example.

Next, the magnetic tool 88 for polishing is placed in the work piece 52, and a predetermined amount of working liquid is injected into the injector 9.
0 is supplied into the work piece 52 from one end in the longitudinal direction.

The tool 88 comprises a magnetic material or a permanent magnet material. If the tool 88 includes a permanent magnet material, the permanent magnet material is magnetized causing the tool 88 to act as a permanent magnet.

The tool 88 may have any shape such as a triangular prism shape, but may have, for example, a rectangular parallelepiped shape having a polarity as shown in FIG. The tool 88 shown in FIG. 7 has four parts 92, 92, 94, 94 which are arc surfaces, and the parts 92, 92 or 94, 94 are arranged so as to contact the surface to be polished.

As the working liquid, a slurry liquid containing abrasive grains can be used. It is preferable that the injector 90 includes an adjusting tool such as a valve that adjusts the supply amount of the processing liquid.

The workpiece 52 is supported so that the height position of the portion on the side where the injector 90 is arranged is slightly higher than the height position of the portion on the opposite side. Therefore, the working liquid moves in the workpiece 52 with the passage of time.

During polishing, a three-phase alternating current is supplied to each coil 46 of the electromagnet 20 so as to generate a rotating magnetic field from the magnetic pole surface of the iron core 42. A method of connecting the coil 46 and the three-phase AC power source is described in, for example, Japanese Patent Application Laid-Open No. 62-102969.

As a result, the rotating magnetic field is generated by changing the polarity of the electromagnet 20, and the tool 88 arranged in the workpiece 52 comes into contact with the inner surface of the workpiece 52 as the rotating magnetic field moves. In the state, it is rotated in the circumferential direction along the inner surface. The rotation speed of the tool 88 can be easily changed by changing the frequency of the alternating current supplied to the electromagnet using an inverter.

During polishing, the slider 56 is reciprocated by the moving mechanism 68 at a frequency lower than the rotation frequency of the tool 88. As a result, the workpiece 52 is reciprocated in the axial direction.

However, the tool 88 arranged in the workpiece 52 is restrained by the magnetic flux generated by the magnetic field generator 16 and is not displaced in the axial direction of the workpiece 52 with respect to the magnetic field generator 16. Therefore, relative movement of the work piece 52 in the axial direction occurs between the work piece 52 and the tool 88.
As a result, the polishing trajectories of the tool drawn on the inner surface of the workpiece intersect with each other, and the inner surface of the workpiece is efficiently smoothed.

During polishing, the chuck 64 is also rotated by the rotating mechanism 78 about the axis of the workpiece 52 at a frequency lower than the rotational frequency of the tool 88. This causes the work piece 52 to rotate about its axis. As a result, when the centers of a plurality of magnetic fluxes deviate from the center of the work piece, the unevenness of polishing is eliminated, and the entire inner surface of the work piece can be made a uniform finished surface.

The rotation frequency of the tool 88, the reciprocating motion frequency of the work piece 52, and the rotation frequency of the work piece 52 can be, for example, about 30 to 50 Hz, 1 to 2 Hz, and 0.1 to 1 Hz, respectively. .

The direction of rotation of the workpiece 52 may be the same as the direction of rotation of the tool 88, or it may be opposite. Further, the rotation and the rehabilitation movement of the workpiece 52 may be continuous or intermittent.

The working liquid in the work piece 52 is the work piece 52.
Even if is rotated, it collects on the bottom of the surface to be polished due to its own weight, and thus adheres to the entire surface of the surface to be polished as the workpiece 52 rotates.

Further, the machining liquid in the work piece 52 is caused by the relative reciprocating motion of the work piece 52 and the tool 88 and by the work piece 52 being inclined with respect to the horizontal line.
The workpiece 52 is moved in the longitudinal direction. As a result of these,
The working liquid in the work piece 52 adheres uniformly over the entire surface to be polished.

Due to the rotation of the tool 88 and the reciprocating motion of the workpiece 52, a relative distance between the workpiece 52 and the tool 88 such that the tool 88 draws a spiral locus on the surface to be polished. Movement occurs. The trajectory of the tool when the workpiece is moved to one side in the axial direction and the trajectory of the tool when moved to the other intersect with each other.

When the polishing by the moving mechanism 68 within the stroke range of the workpiece 52 is completed, the gripping position of the workpiece 52 on the chuck 64 is changed, and the polishing within the next range is performed.

The range of reciprocating motion of the workpiece 52 can be adjusted by changing the mounting position of the crankshaft 74 on the cam disk 72, for example.

During the polishing, it is preferable to supply the working liquid into the work piece 52 continuously or intermittently. Further, it is preferable to arrange the chute and the container for receiving the working fluid flowing out from the workpiece 52 on the side opposite to the injector 90 side.

Although one magnetic field generator 16 is used in the illustrated example, a plurality of magnetic field generators 16 may be sequentially arranged in the axial direction of the workpiece 52. In this case, the tools may be arranged for each magnetic field generator, or one tool may be rotated together by a plurality of magnetic field generators.

Instead of displacing the position of the magnetic pole surface 50 by moving the entire electromagnet 20 with the screw rod 38,
The position of the magnetic pole surface 50 may be displaced by moving the iron core 42 with respect to the coil 46.

In the example of the electromagnet 20 shown in FIG.
6 is supported by the corresponding bracket 36 by a fixture 96, the iron core 42 is movably inserted in the coil 46, and is connected to the tip end of the screw rod 38 by a connector 48. Therefore, when the handle 32 is rotated,
The iron core 42 is moved in the radial direction of the support 18.

Instead of moving the electromagnet 20 by the handle 32, it may be moved by an electric motor. If you do this,
Since the position of the magnetic pole surface 50 in the radial direction of the support can be displaced following the inner diameter of the workpiece, it is possible to polish workpieces having different inner diameters in the longitudinal direction.

According to the magnetic polishing apparatus 10, since the electromagnet 20 is supported on the support 18 so that the position of the magnetic pole surface in the radial direction of the support 18 and thus the inner surface to be polished can be changed, the size of the workpiece 52 can be adjusted. Regardless of the pole face 50
Can be set to a position slightly separated from the outer peripheral surface of the work piece 52, so that the magnetic flux generated from the magnetic field generator 16 effectively acts on the tool 88 arranged in the work piece 52. Therefore, various kinds of workpieces having different sizes can be efficiently polished.

Further, since the coil 46 has a truncated pyramid shape (or a truncated cone shape) and the outer diameter of the coil on the side of the magnetic pole surface 50 is smaller than the outer diameter on the opposite side, for example, Even if the electromagnets 20 are moved to the position shown by the dotted line in FIG. 2, the adjacent electromagnets 20 do not come into contact with each other. Therefore,
When the electromagnets 20 are moved to a position where adjacent electromagnets 20 come into contact with each other, the space defined by the magnetic pole surface 50 becomes small.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a magnetic polishing apparatus according to the present invention.

FIG. 2 is an enlarged view showing one embodiment of a magnetic field generator.

FIG. 3 is a sectional view taken along line 3-3.

FIG. 4 is an enlarged view showing a relationship between a second bevel gear and a screw rod.

FIG. 5 is a diagram showing an example of an electromagnet.

FIG. 6 is a perspective view showing an example of a drive mechanism.

FIG. 7 is a perspective view showing an example of a magnetic tool for polishing.

8 is an enlarged sectional view similar to FIG. 3, showing another embodiment for changing the position of the magnetic pole surface.

[Explanation of symbols]

 10 Magnetic Polishing Device 12 Frame 16 Magnetic Field Generator 18 Support 20 Electromagnet 24 First Bevel Gear 26 Large Gear 28 Small Gear 30 Shaft 32 Handle 34 Second Bevel Gear 38 Screw Rod 42 Iron Core 46 Coil 50 Magnetic Pole Surface 52 Workpiece Object 54 Drive mechanism 88 Magnetic tool for polishing

Claims (4)

(57) [Claims] 1. A magnetic polishing apparatus for polishing a circular inner surface of a workpiece, wherein an axis of the workpiece is held in a state where a tool disposed in a space defined by the inner surface is in contact with the inner surface. A magnetic field generating means for generating a magnetic field for rotating around, wherein the magnetic field generating means is a plurality of electromagnets having a coil wound around an iron core, the iron core extending in a radial direction of the inner surface, and the magnetic pole surface of the iron core being A magnetic polishing apparatus comprising: a plurality of electromagnets arranged on the side of the axis of the workpiece; and a support mechanism that supports the electromagnets so that the position of the magnetic pole surface in the radial direction can be varied. 2. The entire electromagnet is supported by the support mechanism so as to be movable in the radial direction, and the coil has a truncated pyramid shape or a conical shape so that a side of the magnetic pole surface is smaller than an opposite side thereof. The magnetic polishing apparatus according to claim 1, which is wound in a trapezoidal shape. 3. The coil is supported immovably in the radial direction by the supporting means, the iron core penetrating the coil movably in the radial direction and the magnetic pole surface in the radial direction. The magnetic polishing apparatus according to claim 1, wherein the magnetic polishing apparatus is supported by the supporting means such that its position can be changed. 4. The support mechanism is provided for each of the electromagnets, and is connected to the iron core of the corresponding electromagnet, and extends in the radial direction, and a screw rod that is screwed with the screw rod and corresponds to the screw rod. A plurality of first bevel gears that are rotatably supported by a support body, and a second bevel gear that meshes with the first bevel gears and is supported by the support body so as to be rotatable about the axis. The magnetic polishing apparatus according to claim 1, 2 or 3, further comprising: a second bevel gear that is formed and a rotating mechanism that rotates the second bevel gear.