JPH1029148A - Method of polishing and tool therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To polish effectively and accurately complicated curved surface without changing and exchanging polishing tools. SOLUTION: This method makes a polishing tool 1 press against a to-be- machined work and rotate and if necessary rock to conduct the polishing work. In this case the polishing tool 1 provides a rubber portion 50 whose variation of hardness with respect to the thermal influence is large, so by controlling the temperature of rubber portion 50, the hardness of the rubber is adjusted, consequently, the contacting surface area is controlled accordingly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing tool which presses a polishing tool against a processing surface of a workpiece, rotates the workpiece and / or the polishing tool, and oscillates the polishing tool if necessary. The present invention relates to a polishing method for performing polishing and a polishing tool used for the polishing method.

[0002]

[Prior art]

(First Prior Art) The polishing method according to the first prior art is as follows.
A polishing method for polishing a workpiece using a polishing tool in which a number of fibers or metal wires are embedded in an elastic body having a rubber hardness of 70 Hs or less, which is disclosed in Japanese Patent Application Laid-Open No. 53-140693.

(Second Prior Art) A polishing method according to a second prior art is a polishing method which uses a spherical polishing tool and provides means for detecting a processing force to control the processing force to a desired processing force. It is disclosed in JP-A-4-244373.

(Third Prior Art) The polishing method according to the third prior art is to obtain a desired appearance quality by performing two-stage polishing of rough polishing and finish polishing depending on the surface roughness of a workpiece. This is a polishing method. When polishing a more complicated free-form surface, it is necessary to keep the accuracy of the shape of the curved surface.Therefore, the contact area of the polishing tool can be further reduced, and the processing conditions can be reduced by dividing the processing surface into smaller pieces. Instead, it was polished using several types of polishing tools having different shapes.

[0005]

However, in the first prior art, there is a problem that the polishing conditions are changed during the polishing process due to the wear and falling off of the fibers and metal wires. The second prior art has a problem that a working force detection device is required, and the shape accuracy cannot be obtained when the working force change is large. For this reason, it has been practically impossible to accurately polish an optical lens having a free-form surface, a mold for molding an optical lens, an optical mirror, and the like with any of the above-described conventional techniques.

In the third prior art, since the removal amount is large in rough polishing, a material having a high rubber hardness is used so that the contact area between the workpiece and the polishing tool is reduced so as not to lose the shape of the workpiece. Had been polished. Further, it is necessary to change the size of the abrasive grains of the polishing pad and the rubber hardness (contact area) according to the removal amount. It is possible to change the contact area by increasing the load, but this method has a drawback that shape accuracy cannot be obtained. In finish polishing with a small amount of removal, in order to shorten the time and increase the polishing power, it is necessary to reduce the rubber hardness as much as possible and take a large contact area as long as the shape is not destroyed. They used different polishing tools.

When the workpiece has a more complicated shape,
In particular, when the minimum curvature of the free-form surface is smaller than the curvature of the polishing tool, the contact area between the polishing tool and the workpiece becomes extremely large, which is a factor of deteriorating the shape accuracy. Therefore,
Reduce the shape of the polishing tool itself. Alternatively, polishing is performed by combining a polishing tool and polishing conditions in accordance with the curvature of the workpiece.

From the above, in the third prior art, in order to ensure the shape accuracy of the workpiece, several types of polishing tools having different rubber hardnesses are required, which increases the cost of the polishing tool and complicates the polishing operation. And increase in polishing time.

[0009]

According to a first aspect of the present invention, there is provided a polishing method, wherein a polishing tool (1) is pressed against a processing surface of a workpiece (3, 4), and the workpieces (3, 4) and And / or rotate the polishing tool (1) and add rocking to it if necessary,
In the polishing method for performing the polishing of the workpieces (3, 4), a polishing tool (1) having a rubber portion (50) having a large rate of change in rubber hardness is used as the polishing tool (1). The contact area between the polishing tool (1) and the workpiece (3, 4) is adjusted by adjusting the temperature of the rubber portion (50) to adjust the rubber hardness of the rubber portion (50). It is characterized by the following.

The polishing method according to a second aspect of the present invention is the polishing method according to the first aspect, wherein the temperature of the polishing liquid is adjusted, the temperature of the air blown to the rubber portion is adjusted, or the resistance wire is adjusted. The temperature of the rubber portion (50) is adjusted by adjusting the calorific value of the rubber portion.

In the polishing tool according to a third aspect of the present invention, a polishing tool (1) is pressed against a processing surface of a workpiece (3, 4), and the workpiece (3, 4) and / or the polishing tool (3) is pressed. In the polishing tool used in the polishing method for performing the above-mentioned workpiece polishing by rotating 1) and swinging the workpiece as necessary, the polishing tool has a rubber portion (50) having a large thermal change rate of rubber hardness. ), The rubber hardness of the rubber portion (50) is adjusted by adjusting the temperature of the rubber portion (50), and the workpiece (3, 4) and the polishing tool (1) are adjusted.
Characterized in that the contact area with the contact is adjustable.

[0012]

When the hardness of the polishing tool is increased by lowering the temperature of the rubber portion, the contact area with the workpiece can be reduced, and it can be used in rough polishing with a large removal amount. Conversely, if the temperature of the rubber portion is increased to lower the hardness of the polishing tool, the contact area with the workpiece can be increased, and adaptation to finish polishing can be performed.

Further, in a more complicated shape, by adjusting (changing) the temperature in accordance with the shape (curvature) being processed, it becomes possible to polish with an optimum contact area, and it is possible to polish accurately. Becomes

As described above, by using the polishing method and the polishing tool of the present invention, the temperature of the rubber portion is adjusted to adjust the rubber hardness, and the contact area between the workpiece and the polishing tool is adjusted. It is not necessary to use a plurality of polishing tools properly, and polishing with one polishing tool becomes possible. In addition, since polishing can be performed with one polishing tool even when the shape is changed, the number of polishing tools is reduced. Further, even in the polishing of a workpiece having a complicated processed surface shape, the number of polishing tools can be reduced, the polishing process can be simplified, and the operation time can be reduced. Furthermore, since the contact area can be adjusted according to the shape of the workpiece, the shape accuracy can be improved.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Embodiment 1 is an embodiment in the case of two-stage polishing.

FIG. 1 shows a hemispherical polishing tool 1 according to this embodiment.
FIG. The polishing tool 1 has a semi-rest shape and has a rubber portion 50 made of nitrile butadiene rubber (NBR).

FIG. 2 shows how the polishing tool 1 is used to polish an optical lens. Reference numeral 2 denotes a polishing pad for a plastic lens, and reference numeral 3 denotes an object to be processed. In this embodiment, the lens is a plastic single-focus spectacle lens. The polishing tool 1 to which the polishing pad 2 is attached and the mounting jig 5 are pressed against the workpiece with an arbitrary constant load of 2 to 20 kg, and the workpiece 3 and the polishing tool 1 and the mounting jig 5 are rotated in reverse to rotate the lens periphery. Swinging spirally or spirally from the center to the center (amplitude)
Polishing is performed while moving while drawing a locus to which is added.

In the rough polishing, a polishing tool # 12 for rough polishing is used.
The polishing pad 2 with abrasive grains of 00 is attached, the temperature of the polishing liquid (or water) supplied from the polishing liquid supply port 6 at the start of processing is set at 10 ° C., and the rubber hardness of the polishing tool 1 itself is set at 60 ° C.
Hs. The polishing tool 1 is pressed against the workpiece 3 with a constant load of 4 kg to make a contact area of about φ10 (mm 2).

On the other hand, in the final polishing, the flocking pad 2 of the flocking type is attached to the polishing tool 1 and the temperature of the polishing liquid (Polyplastic 203Z manufactured by Fujimi Incorporated) supplied from the polishing liquid supply port 6 is raised to 80 ° C. Rubber hardness 40
Hs and press with 4Kg load to reduce the contact area to about φ3
Polishing with a width of 0 (mm2). In both polishing operations, the polishing liquid at the above temperature was continuously discharged in order to maintain the contact area during processing. As a result, the workpiece 3 having sufficient appearance quality and shape accuracy as a single focus spectacle lens was obtained without changing the polishing tool 1.

(Comparative Example 1) Polishing tool 1 used in Example 1
Rough polishing was performed under the same conditions, the load in the final polishing was set to 12 kg, and the temperature of the polishing liquid was set to 10 ° C., and the workpiece 3 was polished in the same manner as in Example 1. The contact area at the time of finish polishing is the same as about φ30 (mm 2). However, the shape precision was remarkably degraded, and the power within one lens fluctuated, and it was not possible to obtain the precision within the standard. Further, the polishing pad 2 was broken during processing, making it difficult to unify polishing conditions, and it was difficult to repeatedly obtain the same result.

Similarly, the polishing load is 4 kg and the temperature of the polishing liquid is 10 kg.
When the final polishing is performed at ℃, shape accuracy can be obtained,
Polishing time is greatly increased and productivity is reduced.

(Embodiment 2) Embodiment 2 is an embodiment in which a workpiece having a more complicated shape is polished.

The workpiece 4 of this embodiment is a plastic multifocal spectacle lens having a complicated shape. FIG. 3 shows a state where a portion having a small curvature is polished, and FIG. 4 shows a state where a portion having a large curvature is polished. In this example, the rubber hardness was adjusted not by adjusting the temperature of the polishing liquid but by adjusting the temperature of air blown to the rubber portion of the polishing tool. Therefore, it is easy to quickly change the temperature of the rubber portion, it is possible to adjust the rubber hardness in response to the change in curvature, and it is possible to accurately polish a workpiece having a complicated shape. became.

Further, since the plastic spectacle lens of this embodiment is weak to heat, if a polishing liquid temperature exceeding 80 ° C. is used, the shape may be lost due to the heat, and the temperature is extremely increased to change the rubber hardness. It is impossible. Therefore, when it is necessary to change the rubber hardness during processing, a means for changing the temperature by blowing air is optimal. A flocked polishing pad 2 is adhered to the surface, and a polishing liquid at room temperature (20 ° C.) is supplied from a polishing liquid supply port 6. By keeping the temperature of the polishing liquid at room temperature, the surface temperature of the multifocal spectacle lens 4 is maintained at 80 degrees or less. When the minimum curvature is 100R or less, the maximum curvature is 50.
In the case of a complicated shape composed of 0R or more, polishing of a portion having a small curvature (FIG. 3) is performed by blowing cold air at 5 ° C. from the blower opening 7 and pressing it with a load of 8 kg to reduce the contact area to about φ20 (mm 2). I do. In the portion where the curvature is large (FIG. 4), the air is blown up to 100 ° C. corresponding to the curvature and the contact area is changed to about φ50 (mm 2) for polishing.
By repeating this method, the entire surface can be polished without changing the polishing tool, and a highly accurate polished surface was obtained.

The shape of the polishing tool 1 is not limited to a hemispherical shape, but may be a spherical shape or an arbitrary (semi-) aspherical shape depending on the shape of the workpiece 4 and processing conditions. Further, the temperature of the rubber portion of the polishing tool 1 can be adjusted by adjusting the amount of heat generated by a resistance wire such as a nichrome wire or a coil.

[0026]

As described above, according to the polishing method and the polishing tool of the present invention, in the two-stage polishing and the polishing of a workpiece having a complicated shape, which required two or more types of polishing tools, polishing is performed. Polishing can be performed without changing or changing tools. As a result, reduction in the number of polishing tools (cost reduction), simplification of the polishing operation, and shortening of the operation time were achieved.

Furthermore, in the case of polishing a free-form surface, the contact area can be adjusted according to the shape of the workpiece to be polished and the like, so that there is also an effect of improving the shape accuracy.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a hemispherical polishing tool according to a first embodiment.

FIG. 2 is a diagram showing a state of polishing a single focus spectacle lens in the first embodiment.

FIG. 3 is a diagram showing a state in which a portion of a multifocal spectacle lens having a small curvature is polished in Example 2.

FIG. 4 is a diagram showing a state in which a portion of a multifocal spectacle lens having a large curvature is polished in Example 2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polishing tool 3, 4 Workpiece 7 Blowing means 50 Rubber part

Claims (3)

[Claims] 1. A polishing tool (1) is pressed against a processing surface of a workpiece (3, 4) to rotate said workpiece (3, 4) and / or said polishing tool (1), The polishing method according to claim 1, wherein said polishing tool (1) has a rubber portion (50) having a large thermal change rate of rubber hardness as said polishing tool (1). Using the tool (1), adjusting the temperature of the rubber portion (50) to adjust the rubber hardness of the rubber portion (50) so that the polishing tool (1) and the workpiece (3, 4) A polishing method characterized by adjusting the contact area with the polishing. 2. The polishing method according to claim 1, wherein the temperature of the polishing liquid is adjusted, the temperature of air blown to the rubber portion is adjusted, or the calorific value of the resistance wire is adjusted. A polishing method, wherein the temperature of the rubber portion (50) is adjusted by the following method. 3. A polishing tool (1) is pressed against a processing surface of a workpiece (3, 4) to rotate the workpiece (3, 4) and / or the polishing tool (1), and A polishing tool used in a polishing method for performing the workpiece polishing by oscillating the polishing tool accordingly, the polishing tool includes a rubber portion (50) having a large thermal change rate of rubber hardness; The contact area between the workpiece (3, 4) and the polishing tool (1) can be adjusted by adjusting the temperature of the rubber part (50) by adjusting the temperature of the rubber part (50). A characteristic polishing tool.