JPS6239172A - Magnetic polishing machine - Google Patents

Abstract

PURPOSE:To enable the concurrent polishing of both surfaces of even a non- magnetic workpiece and ensure efficient polishing work by forming a magnetic field between two opposite discs and a brush of magnetic abrasives. CONSTITUTION:Magnetic abrasives 40 are filled in between two discs 23a and 23b located opposite to each other about a rotary shaft 21. Then, an exciting coil 27 is made electrically live and a magnetic field is formed between said pair of discs 23a and 23b via a yoke 26. The magnetic field so formed causes said abrasives 40 to be positioned as opposed to each other, and a magnetic brush of said abrasives 40 is formed at a mid-distance between the two discs 23a and 23b. On the other hand, a disc D as a workpiece held on a retaining shaft 28 is inserted in said magnetic brush and then a rotary shaft 21 and the retaining shaft 28 are driven clockwise by a motor, thereby enabling the magnetic brush of said abrasives 40 to process both surfaces of the disc D concurrently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a magnetic polishing apparatus that orients magnetic abrasive in a magnetic field to form a magnetic brush and polishes an object to be polished with this brush. The present invention relates to a magnetic polishing apparatus capable of polishing non-magnetic objects to be polished, and also capable of polishing both sides of stamped disk-shaped objects.

[Technical background and problems with conventional technology] The work of polishing an object is to bring an abrasive that is harder than the object into contact with the object. The abrasive is slid onto the polishing surface at a speed and pressure depending on the conditions.

In this polishing operation, uniform and appropriate pressure of the polishing agent is essential in order to precisely polish the polished surface. To achieve this, technical innovations such as the material of the wrap that holds the abrasive are required. Conventionally, cloth, rubber, synthetic resin, etc. have been used as this material.

In addition, recently there have been an increasing number of objects to be polished that must be precisely polished. Examples of this type of object to be polished include magnetic disks, magnetic tapes, aluminum disks, synthetic resin disks, and synthetic resin films.

These objects to be polished have a relatively wide polishing surface, and must be polished with high precision.

A conventional example of a polishing apparatus for polishing disks among objects to be polished will be explained with reference to FIG. 3 and FIG. 4, which is a side view thereof. In this polishing apparatus, the disk D is rotationally driven clockwise or counterclockwise in FIG. 5 by a predetermined rotational drive device. In addition, disk D has a polishing disk l.
is facing from both sides. Each polishing disk 1 is composed of a polishing pad 3 and a rigid plate 4 that supports the polishing pad 3, and the polishing pad 1 is rotatably driven by a rotating shaft 2. The polishing pad 3 is made of polyurethane.
It is made of a mixture of rubber and abrasives.

In this type of polishing apparatus, polishing is performed by pressing each polishing disk l against both surfaces of the disk D and rotating it. Since the polishing pad 3 is made of urethane foam mixed with an abrasive, its elastic properties allow the abrasive to contact the surface of the disk D evenly with uniform pressure, resulting in polishing. It will be done. By using the polishing pad 3 mixed with this kind of resin,
It has been devised to achieve appropriate abrasive contact pressure. As this type of polishing device, for example, JP-A-57-1
There is one disclosed in Japanese Patent No. 831334.

However, even if such improvements are made to the polishing pad 3, there is a limit to the ability to accurately set the contact pressure of the polishing agent against the disk D, and the polishing pad 3 may wear out as the polishing work progresses. There are also problems.

Furthermore, recently, polishing devices that utilize magnetism have been considered. In this type of magnetic polishing apparatus, a magnetic polishing agent is oriented in a magnetic field to form a magnetic brush, and the object to be polished is polished using this magnetic brush. In this magnetic polishing device, the strength of the magnetic field orients the abrasive to form a uniform abrasive surface, making it easier to perform high-precision polishing work with appropriate pressure.

As an example of polishing a relatively large polishing surface such as a disk D using this magnetic polishing device, a rotating disk having magnetic poles is provided on a work table that supports the object to be polished, and the object to be polished is There is a method in which a magnetic field is formed as a circuit that passes through the rotating disk and the object to be polished, and a magnetic abrasive is oriented and interposed in the magnetic field between the rotary disk and the object to be polished, thereby forming a brush made of the abrasive. However, this type of magnetic polishing device has a structure in which the lines of magnetic force pass through the inside of the object to be polished, so it can only process objects to be polished that are magnetic, and has the disadvantage that it cannot polish disks made of aluminum or resin. .

FIG. 5 shows another conventional example of a magnetic polishing device capable of polishing disks and the like. In this magnetic polishing device, a coil 7 is wound around an iron core 6 provided in a yoke 5 to constitute an electromagnet. Magnetic poles 8a and 8b are provided on the lower surfaces of the yoke 5 and the iron core 6, and both the magnetic poles 8a and 8b are joined via a nonmagnetic material 9. The portion where the non-magnetic material 9 is interposed faces the disk D, which is the object to be polished, on the work table 10. In this polishing apparatus, when the disk D is made of a magnetic material, lines of magnetic force emerging from one magnetic pole 8a pass through the disk D and return into the other magnetic pole 8b. A magnetic abrasive Lf is interposed between the magnetic poles 8a, 8b and the disk D, and this abrasive is oriented in a magnetic field to form a brush shape. By relatively moving the magnetic poles 8a, 8b and the work table 10, the surface of the disk D will be polished by the magnetic brush of the polishing agent. Further, when the disk D as the object to be polished is formed of a non-magnetic material, a plate 11 made of a magnetic material is placed on the work table 10, and the disk D is placed on it. With this configuration, a magnetic circuit is formed from the magnetic pole 8a through the magnetic plate 11 to the magnetic pole 8b, and by interposing the abrasive in this magnetic field, an abrasive brush can be formed. Therefore, it becomes possible to polish a non-magnetic object to be polished. This type of magnetic polishing device is known, for example, from Japanese Unexamined Patent Publication No. 5
It is disclosed in Japanese Patent No. 9-1160.

However, such a magnetic polishing apparatus has the disadvantage that it cannot polish only one side of a disc-shaped object to be polished. Therefore, the polishing operation must be performed twice, on the front and back sides, and each time the magnetic field must be destroyed to recover the abrasive, and the abrasive must be supplied again to form a brush.
The disadvantage is that the setup is complicated. Further, in the magnetic polishing apparatus shown in FIG. 5, the object to be polished is limited to a flat object such as a disk, making it impossible to polish parts of various shapes. Therefore, the applications are limited. [Object of the Invention] The present invention has been made by focusing on the above-mentioned conventional problems. It also enables polishing of non-disc-shaped objects, and also enables polishing of non-magnetic objects.Moreover, the orientation density of the magnetic brush that performs the polishing work is increased to polish hard objects. It is an object of the present invention to provide a magnetic polishing device that can polish even objects to be polished with high precision.

[Summary of the invention]

In the magnetic polishing device according to the present invention, a pair of discs formed of a magnetic material are driven to rotate facing each other, and both ends of a yoke of the magnetic material passing directly through an excitation coil are opposed to each disc in the L. One of the disks has an S magnetic pole and the other has an N magnetic pole, and a magnetic abrasive is interposed between the two disks, and the polishing agent is oriented in a magnetic field. A magnetic brush is formed using a polishing agent, and a member for holding the object to be polished is provided on the side of the magnetic brush.

In the present invention, magnetic poles are attached to discs that rotate opposite each other, and polishing is performed using a magnetic brush formed between the magnetic poles. Therefore, even if the workpiece is disc-shaped, both sides of the workpiece can be polished at the same time. Be able to polish. Also, if you do not install a connecting rod or the like in the middle of the disk, a magnetic brush can be formed over the entire area facing the disk, and it is also possible to perform polishing work by passing a rod-shaped object to be polished through the magnetic brush. It is. Furthermore, since the magnetic poles of the disks are formed by an excitation coil and a yoke, the magnetic force between each disk can be increased, making it possible to form a magnetic brush oriented with high density.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a front view showing a magnetic polishing apparatus according to the present invention, and FIG.
The figure is its left side view.

Reference numeral 21 in the figure is a rotating shaft. This rotary shaft 21 is supported by bearings 22a and 22b, and a pair of discs 23a and 23b are fixedly mounted opposite to each other on the 0-rotary shaft 21, which is rotatably driven by a drive source such as a motor. has been done. The disks 23a and 23b are connected by a connecting shaft 24 having a slightly smaller diameter. This disk 23 a
and 23b are made of a magnetic material such as soft iron.

Further, the rotating shaft 21 has a portion connected to the disks 23a and 23b formed of a magnetic material 21a, and a bearing 2.
The part supported by 2a and 22b is a non-magnetic material 21b
is formed by. Then, the magnetic material 21a part and the non-magnetic material 21b part form a non-magnetic joint 27.
connected by. Further, a fin 25a is provided on the opposing surface of the disk 23a, and a fin 25b is provided on the opposing surface of the other disk 23b. These fins 25a and 25b
are made of a magnetic material, and as shown in FIG. 2, four disks are fixed radially around the rotating shaft 21 to each of the disks 23a and 23b. This fin 25
a and 25b are provided to partially increase the ai east density of the magnetic field formed between each disk 23a and 23b.

Further, reference numeral 26 is a magnetic yoke for forming a magnetic pole. An excitation coil 27 is attached to this yoke 26. The yoke 26 is formed into a U-shape and is inserted into the excitation coil 27, and both ends thereof are connected to the disk 23.
It faces the outer surfaces of a and 23b. Further, the magnetic body 21a portion of the rotating shaft 21 is inserted into a shaft hole 26 formed in the yoke 26.
It is inserted in a. When the excitation coil 27 is energized, magnetic flux flows through the yoke 26, and one disk 23a becomes a north pole, and the other disk 23b becomes a south pole.

Reference numeral 28 is a holding shaft. This holding shaft 28 is rotatably supported by a bearing 29. Further, the holding shaft 28 is rotationally driven by a motor. A holder 28a using a nut or the like is provided at the tip of the holding shaft 28.
The object to be polished, such as the disk D, is held by this holder 28a.

As shown in FIG. 2, struts 32, 33 and 34 are fixedly installed on the pedestal 31. As shown in FIG. The bearing 22 is attached to the support column 32.
a and 22b are held, thereby supporting the rotating shaft 21. A bearing 29 is held on the column 33,
This supports the holding shaft 28. Also, pillar 3
4, an excitation coil 27 is fixedly installed.

Next, the polishing operation will be explained.

The magnetic abrasive 40 is filled between the two disks 23a and 23b. When the excitation coil 27 is energized, the yoke 2
A magnetic field is formed between the disks 23a and 23b via the magnetic field 6. The magnetic abrasive 40 is oriented by this magnetic field, and a magnetic brush of the magnetic abrasive is formed between the two disks 23a and 23b. On the other hand, the disk D, which is the object to be polished, is inserted into the magnetic brush formed by the abrasive 40 while being held by the holding shaft 28 . The rotating shaft 21 and the holding shaft 28 are rotationally driven by the motor clockwise in FIG. 2, that is, in the same direction.

Then, both sides of the disk D are simultaneously polished by the magnetic brush of the polishing agent 40. As shown in Figure 2, disk 2
3 and the disk D rotate in the same direction, the relative speed between the disk D and the magnetic brush of the abrasive 40 can be increased. Further, in part (A) in FIG. 2, the angular velocity of the disk D is small, but the angular velocity of the brush of the abrasive 40 is correspondingly large. In part (B), conversely, the angular velocity of the disk D is large and the angular velocity of the brush is small. In this way, the speed differences between the radii of the rotating bodies are compensated for each other, so that each part can be polished under uniform conditions.

Further, since the magnetic field is formed by the excitation coil 27, the magnetic field formed between the two disks 23a and 23b can be made considerably strong. Also, disks 23 a and 2
Since the fins 25a and 25b are provided on the opposing surfaces of the fins 3b, the magnetic flux density is partially high at the opposing portions of the fins 25a and 25b. Therefore, disks 23a and 23
The magnetic brush of the magnetic abrasive 40 formed between the fins 25a and 25b has a high orientation density, and the orientation density is even higher at the fins 25a and 25b. Therefore, even if the object is hard to be polished, its surface can be polished with high precision. Furthermore, by changing the amount of radio waves applied to the excitation coil 27, the magnitude of the magnetic field between the disks 23a and 23b can be changed, and the orientation density of the magnetic abrasive 40 can be changed. Therefore, when polishing a disk D made of resin, etc., the orientation density of the magnetic polishing agent 40 can be lowered to form a brush suitable for the material.

Further, it is also possible to polish a long object to be polished using the magnetic polishing apparatus according to the present invention. In this case, a long object to be polished is fed in a direction across the brush of the abrasive 40 and polished by the rotating magnetic brush.

Also, the connecting shaft 24 between the disks 23a and 23b is eliminated,
If the two discs 23a and 23b are rotated in synchronization with separate motors, a magnetic brush can be formed over the entire area between the discs 23a and 23b. This configuration is particularly suitable for polishing a long object to be polished.

Magnetic polishing agent 40 used in the magnetic polishing device according to the present invention
may be the same as that previously used. However, in the present invention, a magnetic field is formed between opposing disks,
Since the abrasive 40 is filled between them to form a brush, the magnetic abrasive suitable for this structure is preferably one with a uniform and fine particle size. Also, those with low specific gravity are easier to handle in practical terms. Examples of magnetic abrasives 40 include alumina-iron, ferrite, or chromium dioxide. Among these magnetic abrasives, ferrite-based abrasives (barium ferrite, etc.) have plate-like particles and therefore have a low polishing rate, but are suitable for high-precision finishing. Furthermore, since chromium dioxide is acicular, it has good orientation in a magnetic field.

In practice, polishing oil and additives are added to the polishing agent to prevent seizure, prevent oxidation of the polishing surface, and prevent the polishing agent from scattering. As these, for example, higher fatty acids, metal soaps of higher fatty acids, higher fatty acid esters, mineral oils, silicone oils, etc., a combination thereof, or a dispersion of these in water can be used.

〔Effect of the invention〕

As described above, according to the present invention, the following effects can be achieved.

(1) In the case of a disk-shaped object to be polished, its front and back surfaces can be polished simultaneously. Therefore, polishing work can be done efficiently.

(2) Since a magnetic field is formed between the discs by the excitation coil, the orientation density of the magnetic brushes between each disc can be arbitrarily set by changing the distribution of the current applied to the coil. Therefore, it becomes possible to configure a magnetic brush according to the material of the object to be polished.

(3) Since a magnetic field is created between the opposing discs to form a polishing agent brush, even objects to be polished made of non-magnetic materials can be polished.

(4) It is possible to polish not only a disc-shaped object but also a long object. As stated in claim 2, if the two disks are not connected, the area between the disks can be widely used as a magnetic brush, and a long object to be polished can be placed at the center between the disks. It is also possible to insert it into the part and polish it.

(5) Since the abrasive comes into contact with the object to be polished with uniform pressure, uniform and proper polishing work can be performed even on a wide polishing surface.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a magnetic polishing apparatus according to the present invention, and FIG.
3 is a front view of a conventional disk polishing device, FIG. 4 is a side view thereof, and FIG. 5 is a sectional view showing a conventional magnetic polishing device for disks. 21... Rotating shaft, 23a, 23b... Disk, 24.
...Connection shaft, 25a, 25b...Fin, 26...
Yoke, 27... Excitation coil, 28a... Holder,
40... Abrasive, D... Disc.

Claims (3)

[Claims] (1) A pair of disks formed of a magnetic material are rotated to face each other, and both ends of a yoke of the magnetic material passing through the excitation coil are opposed to each of the disks,
An S magnetic pole is formed on one side of the disk, and an N magnetic pole is formed on the other side, and a magnetic abrasive is interposed between the two disks, and a magnetic brush is created by the abrasive that is oriented in a magnetic field. A magnetic polishing device in which a holding member for holding an object to be polished is provided on the side of the magnetic brush. (2) The magnetic polishing apparatus according to claim 1, wherein the object to be polished is disk-shaped, and both surfaces of the object to be polished are polished within a magnetic brush while being rotated by a holding member. (3) The magnetic polishing device according to claim 1, wherein the opposing disks are not connected but are driven to rotate in synchronization with each other, and a magnetic brush is formed over the entire area of the disks.