JPS63232946A - Abrasive method and polishing tool - Google Patents

Abstract

PURPOSE:To secure forming capacity for a highly accurate surface form and good surface roughness, by making a magnetic fluid solution collide with a workpiece surface with the relative motion of a polishing tool, having a member generating a magnetic field, to a workpiece, and polishing the workpiece. CONSTITUTION:A polishing tool 12 has a cylindrical turning shaft 14, and a spherical body 16 to be constituted of a member, whose material generates a magnetic field, is connected and fixed to the tip part. And, the spherical body 16 of the polishing tool 12 is rotated in a magnetic fluid solution 22, and the ambient magnetic fluid solution 22 is dragged by attraction by dint of magnetic force, whereby the necessary flow velocity is given to the magnetic fluid solution 22. Likewise, the sherical body 16 is approached to such a part that should like to polish a workpiece 20 whereby magnetite grains in the magnetic fluid solution 22 are made to collide with a work surface, thus polishing takes place. Accordingly, dragging efficiency of the magnetic fluid solution 22 can be raised up, so that forming capacity for a highly accurate surface form and very favorable surface roughness both are obtainable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is suitably used for polishing optical elements used in optical lenses, etc., or for finishing high-precision molds.
This invention relates to a polishing method and a polishing tool.

[Conventional technology]

Conventionally, polishing involves placing a workpiece and a polishing tool in a polishing liquid, rotating the polishing tool, and causing the polishing liquid to collide with the surface of the workpiece to polish the surface of the workpiece. method is known.

A conventional polishing method of this type will be explained with reference to FIG.

FIG. 4 is a schematic side view showing a conventional polishing method.

In the figure, 2 is a conventional polishing tool. The polishing tool 2
1 is a cylindrical rotating shaft 4, and a spherical polyurethane ball 6 made of resin such as polyurethane is connected and fixed to the tip of the shaft 4.

Further, numeral 8 shown in the figure is a workpiece. The workpiece 8 together with the polyurethane bulb 6 of the polishing tool 2 is placed in a polishing liquid 10 . The polishing liquid 10 contains polishing abrasive grains.

Then, by rotating the polyurethane ball 6 in this polishing liquid 10 and causing the surrounding polishing liquid 10 to circulate, a necessary flow velocity is given to the polishing liquid 10, and the polyurethane ball 6 is used to polish the workpiece 8. By approaching the part to be processed, dynamic pressure of the polishing liquid 10 is obtained between the I-urethane ball 6 and the workpiece 8, and polishing is thereby performed.

[Problem that the invention seeks to solve]

However, the conventional polishing method described above has the following problems.

That is, the first problem is that it is difficult to improve the processing accuracy of polyurethane balls, so it is not possible to bring the polyurethane balls very close to the workpiece. Otherwise, minute scratches will occur on the surface of the workpiece, making it impossible to obtain a good surface roughness.

The second problem is that when a conventional polyurethane ball is rotated, the rate of change in the polishing fluid flow rate due to the distance from the workpiece near the polyurethane ball is as shown in the graph in Figure 5. Since the surface of the ball decreases rapidly as it moves away from the surface of the workpiece, in order to apply sufficient dynamic pressure to the processing point, the polyurethane ball must be brought closer to the workpiece. That is, this poses a risk of contact between the polyurethane bulb and the workpiece, similar to the first problem mentioned above. Also, since the processing accuracy of the ball is poor, it is impossible to get close to it for this reason.

The third problem is that in the conventional example, the tool still has to be close to the workpiece, so it is necessary to have a very precise tool movement system.

The fourth problem is that because of the above, it is difficult to maintain appropriate processing conditions, resulting in very poor processing efficiency.

The conventional example has the above-mentioned problems.

〔the purpose〕

The present invention has been made in view of the problems of the prior art described above.
), its purpose is to improve the efficiency of polishing in conventional polishing methods, thereby making it possible to form highly accurate surface shapes and obtain very good surface roughness. An object of the present invention is to provide a polishing method and a polishing tool.

[Means for solving problems]

According to the present invention, the above object is achieved by arranging a workpiece and a polishing tool having a member that generates a magnetic field in a magnetic fluid liquid, and moving the polishing tool relative to the workpiece to A polishing method is provided in which polishing is performed by colliding a workpiece with a surface of a workpiece, and the polishing tool used in the method is characterized by having a member that generates a magnetic field. Ru.

〔Example〕

Embodiments of the polishing method and polishing tool according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic side view showing an embodiment of the polishing method of the present invention.

In the figure, 12 is a polishing tool of the present invention.

The polishing tool 12 has a cylindrical rotating shaft 14 .

A spherical body 16, which is made of a material that generates a magnetic field and has a spherical shape, is connected and fixed to the tip of the shaft 14.

Further, the illustrated reference numeral 20 is a workpiece. The workpiece 20, together with the sphere 16 of the polishing tool 12, is placed in a ferrofluid liquid 22.

The aforementioned magnetic fluid liquid 22 will be explained. This magnetic fluid liquid is a material that exhibits magnetism in a liquid state, and is generally made by stably dispersing magnetite particles (ferromagnetic fine particles) of colloidal size (about 0.01 μm in diameter) in a liquid phase. This magnetic fluid liquid apparently exhibits properties such that the liquid itself has magnetism. Further, in addition to magnetite particles, a material made by dispersing fine ferrite particles in the liquid phase may also be used.

Then, the polishing tool 12 is placed in the magnetic fluid liquid 22 as described above.
By rotating the sphere 16 and causing the surrounding magnetic fluid 22 to be drawn around by magnetic attraction, the necessary flow velocity is imparted to the magnetic fluid liquid 22.

First, by bringing the sphere 16 close to the part of the workpiece 20 that is to be cut, the magnetite particles in the fb magnetic fluid 22 are placed between the sphere 16 and the part of the workpiece 20 that is to be cut. By adding 20 parts to Boho's arrows, the child's processing is completed.

The above is one explanation of the basic processing principle of the Q1 horse mackerel method of the present invention.

What follows is the effect of the polishing method mentioned above. I will clarify.

Figure 2 #'i, uninvented polishing tool 12 and magnetic fluid liquid 22
The amount of damage around the U tool when it is rotated inside, [! ; It is a graph showing 1 shift speed Δ.

As shown in the graph of No. 21>, the magnetic field of the 16 spheres surrounded by tI, which is formed by a cup material that generates a magnetic field.
Since the body fluid 22 is sucked into the 7L medium, the magnetic g,
The flow rate of the body fluid 22 is low. Even if it goes from 1 to 16, it will not drop suddenly.

Even if the molten body (16t) and the processed material (20mm) are sufficiently connected, it is possible to perform the polishing process at a lower efficiency.

This also increases the apparent safety.

Furthermore, if ultrafine powder (particle size: several xoi) of silicon or the like is included as an abrasive (abrasive grain) in the magnetic fluid liquid 22, the polishing ability can be further improved.

The above is an explanation of the effects of the polishing method of the present invention.

Next, an example of an apparatus for actually carrying out the polishing method of the present invention will be described.

FIG. 3 is a schematic diagram showing an embodiment of a polishing apparatus for carrying out the polishing method of the present invention.

In FIG. 3, reference numeral 50 denotes a base, and a y-table 5 is mounted on the nuclear base and is movable back and forth in the X direction relative to the base.
2 is installed. 54 is a motor for driving the movement of the y-table, and an encoder 5 is attached to the motor.
6 is attached, and the amount of movement of the y table in the X direction is detected by the encoder. On the X table 52, there is a
A table 58 is attached. Reference numeral 60 denotes a motor for driving the movement of the X table. An encoder 62 is attached to the motor, and the amount of movement of the X table in the X direction is detected by the nuclear encoder.

A polishing tank 64 is fixedly installed on the X-table 58.

A support 66 is fixed in the nuclear polishing tank, and a polished object holder 70 is attached to the support by a shaft 68. The holder is L-shaped and has a shaft 68 connected to its vertical surface. The axis is oriented in the X direction, so the holding body 70 is rotatable in the X direction. A motor 72 is attached to the support 66.
Its drive rotation shaft is coupled to the shaft 68.

On the other hand, a support 74 is fixed to the X-table 58 on the outside of the @mass tank 64. A vertical guide 76 is formed on the support, and an abrasive tool holder 78 is movable vertically along the guide.
is installed.

The holding body is equipped with a motor 8 so as to be rotatable in the X direction.
0 is supported. A sphere 84 that generates a magnetic field is attached to the lower end of the rotating shaft 82 of the motor 80. A motor 86 is attached to the holder 78, and its driving rotation shaft is connected to the motor 80, and can drive the rotation of the motor 80 in the X direction. 88fi is an air cylinder serving as a driving means for moving the holding body 78 in the vertical direction along the guide 76, and the tip of the a-rad 90 of the air cylinder is connected to the holding body 78.
is connected to.

Reference numeral 92 denotes a control device, into which the y-table movement amount and the X-table movement amount are inputted from the encoder 56.
0.86 and the air cylinder 88 or motor are driven by the command from the control device #92.

When polishing using the polishing device described above, the holding body 70
The object to be polished 100 is fixed on top. The object to be polished is finished to a predetermined surface roughness and shape by pre-processing.

In this embodiment, the surface to be polished U1 of the object to be polished 100 has a concave shape.

Further, an appropriate amount of the aforementioned mother fluid 102 is injected into the polishing tank 64.

The surface of the object to be polished 100 is polished by rotating the polishing tool in the A rotation direction shown in the figure in the above-mentioned A υ direction, and applying a flow velocity to the magnetic fluid 102 by rotating it.

Also, in other embodiments of the present invention, the spherical portion of the polishing tool does not necessarily have to be spherical, but may be hemispherical or other shapes.

Further, the pole direction of the spherical magnet may be placed in any direction with respect to the rotation axis.

Further, the sphere that generates the magnetic field may be an electromagnet.

〔Effect of the invention〕

As explained above in detail and specifically, according to the present invention,
Since it is possible to increase the efficiency of the rotation of the magnetic fluid, which is the polishing liquid, it is possible to form a highly accurate surface shape and to obtain a very good surface roughness.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing an embodiment of the polishing method of the present invention, FIG. 2 is a graph showing the rotation speed of the present invention, and FIG. 3 is a schematic diagram showing an embodiment of the polishing apparatus of the present invention. FIG. 4 is a schematic side view showing the conventional polishing method, and FIG. 5 is a graph showing the trailing speed according to the conventional example. 12... Polishing tool, 16... Sphere that generates a magnetic field,
20... Workpiece, 22... Magnetic fluid liquid.

Claims (2)

[Claims] (1) A workpiece and a polishing tool having a plurality of through holes penetrated inside the main body are placed in a polishing liquid, and a highly viscous substance is discharged from the inside of the polishing tool through the through holes, and A polishing method that performs polishing by causing the polishing liquid to collide with the surface of a workpiece by moving a tool relative to the workpiece. (2) A polishing tool characterized by having a plurality of through holes penetrated inside the main body.