JP3631280B2 - Glass lens centering wheel - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an electrodeposition tool. More specifically, the present invention relates to an electrodeposition tool having a small grinding resistance and a long life.
[0002]
[Prior art]
The electrodeposition tool is a grinding and polishing tool in which superabrasive grains are fixed on a base metal by electroplating. Since the superabrasive cutting edge protrudes and has a sharp abrasive edge, the sharpness is good, the grinding efficiency is high, and the superabrasive concentration is high, so there is little uneven wear of the abrasive. Since an electrodeposition tool can perform high-efficiency and high-precision machining, the electrodeposition tool is widely applied to various work materials from soft rubber to hard carbide.
An electrodeposition tool usually consists of a single layer of abrasive grains, and no self-generating action occurs due to falling off of the grains. For this reason, if chips generated by grinding adhere to the gaps between the superabrasive grains on the tool surface or are welded by frictional heat, there is a problem that the grinding force is greatly reduced.
Various attempts have been made to prevent clogging of the electrodeposition tool due to chips. Japanese Patent Laid-Open No. 63-16975 proposes a method of coating a surface of an electrodeposition tool with a titanium-based ceramic compound by a PVD method. Titanium-based ceramic compound films have the advantage of being less susceptible to clogging because of their low adhesion to chips discharged from the work material, but the electrodeposition tool is exposed to high temperatures during coating by the PVD method. Therefore, it is unavoidable that the electrodeposition tool is thermally distorted, and sometimes the electrodeposition tool is damaged. For this reason, there has been a demand for the development of an electrodeposition tool that is not exposed to high temperatures during processing and has an effective clogging prevention effect.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide an electrodeposition tool that is manufactured by a method that does not cause thermal distortion, has no clogging during grinding, has a low grinding resistance, and has a long life.
[0004]
[Means for Solving the Problems]
As a result of intensive research to solve the above problems, the present inventors have found that clogging due to chips can be reduced by further applying gold or gold alloy plating to the electrodeposition tool. Based on this, the present invention has been completed.
That is, the present invention
(1) The surface of the layer on which the superabrasive grains of the electrodeposition tool obtained by fixing the superabrasive grains to the base metal by electrodeposition is further plated with 2 to 10 μm of gold or gold alloy. A glass lens centering wheel; and (2) a glass lens centering wheel according to item (1), wherein the gold alloy is an alloy of gold and cobalt or nickel;
Is to provide.
[0005]
In the present invention, an electrodeposition tool obtained by fixing superabrasive grains to a base metal by electrodeposition can be produced by a known method. As the base metal, iron (S45C) can be preferably used, but other metals and alloys can also be used depending on applications. As superabrasive grains, there are diamond abrasive grains and CBN abrasive grains. As diamond abrasive grains, either natural diamond or synthetic diamond can be used, and it has an appropriate particle size and particle size distribution depending on the application. You can choose one. The superabrasive grains are electrodeposited to form a single layer on the base metal by plating nickel or the like.
In the present invention, gold or gold alloy plating is further applied to an electrodeposition tool in which superabrasive grains are fixed to a base metal by electrodeposition. There is no restriction | limiting in particular in the method of performing gold | metal | money or gold alloy plating, The well-known gold | metal | money or gold alloy plating method can be used. Examples of plating methods that can be used include a cyanide plating bath method using gold potassium cyanide and a phosphate bath method using gold chloride.
In the present invention, an electrodeposition tool in which superabrasive grains are fixed to a base metal by electrodeposition is preferably free from dirt due to oil or fat on the surface when plating gold or gold alloy. If oil or grease remains on the surface, the plated gold or gold alloy layer tends to peel off. In the case of gold or gold alloy plating subsequent to electrodeposition of nickel or the like for fixing superabrasive grains, the surface was hardly contaminated, but electrodeposition for fixing the superabrasive grains was performed. After that, when the electrodeposition tool is left for a long period of time, it is preferable to perform degreasing and water washing prior to gold or gold alloy plating. Degreasing and rinsing can be performed by degreasing the electrodeposition tool with an appropriate solvent and the like, drying it, and immersing it in dilute hydrochloric acid or an aqueous sodium cyanide solution to remove the oxide on the surface.
[0006]
In the present invention, the temperature of the plating bath for performing gold or gold alloy plating can usually be selected in the range of room temperature to 80 ° C. When coating by the PVD method, the electrodeposition tool is usually exposed to a high temperature exceeding about 200 ° C., so that it is inevitable that the electrodeposition tool is thermally distorted, and sometimes the electrodeposition tool may be damaged. When gold or gold alloy plating is performed, the electrodeposition tool is not exposed to such a high temperature, so that there is no possibility of causing thermal distortion or damage to the electrodeposition tool.
In the present invention, the thickness of the gold or gold alloy layer plated on the electrodeposition tool is preferably 2 to 10 μm, and more preferably 3 to 5 μm. If the thickness of the gold or gold alloy layer is less than 2 μm, the metal part may be exposed during use of the electrodeposition tool. A thickness of 10 μm is sufficient for the gold or gold alloy layer, and a thickness of the gold or gold alloy layer exceeding 10 μm is usually not necessary.
In the present invention, the current density for performing the gold or gold alloy plating is preferably 0.2~0.5A / dm ^2. When the current density is less than 0.2 A / dm ² , it takes a long time to perform gold or gold alloy plating with a necessary thickness. When the current density exceeds 0.5 A / dm ² , the precipitated crystals become coarse and may be easily peeled off. In the cyanide plating bath method, a gold or gold alloy layer having a thickness of 1 μm is formed by plating for about 2 hours at a current density of 0.5 A / dm ^{2. In} the phosphate bath method using gold chloride, 0.5 A is used. If plating is performed at a current density of / dm ² for about 6 hours, a gold or gold alloy layer having a thickness of 1 μm is formed. You can ask for it.
Since gold is the most precious metal, gold is deposited on the surface by substitution only by immersing the electrodeposition tool in the plating bath. Since such a precipitate has a weak adhesion with the base metal and is easily peeled off, in the present invention, it is preferable to connect the cathode to the electrodeposition tool in the air and quickly immerse it in the plating bath after starting to flow. . There is no restriction | limiting in particular in the material of the anode to be used, For example, hard carbon, stainless steel, nichrome steel etc. can be used. If the plating of gold or gold alloy is continued, the precipitated crystals become coarse over time, so the electrodeposition tool is taken out of the plating bath from time to time and rubbed with a brush to obtain a smooth plating surface by repeating the plating again. Can do. After finishing plating, the electrodeposition tool is cleaned. If the cyanide remains on the surface due to insufficient washing, the color may change or a stain may be left. Therefore, it is desirable to wash thoroughly with water, then wash with warm water and dry. From the weight difference between the electrodeposition tools before and after plating, the weight of the plated gold or gold alloy can be obtained, and the thickness of the gold or gold alloy layer can be confirmed.
[0007]
In the present invention, the electrodeposition tool is preferably plated with a gold alloy having a higher hardness than pure gold having a relatively low hardness. Examples of such a gold alloy having high hardness include an alloy of gold and cobalt, an alloy of gold and nickel, and the like. The gold-cobalt alloy plating can be performed, for example, by adding cobalt cyanide to a cyanide plating bath. Since the monopolar potential of cobalt is much lower than the monopolar potential of gold, the amount of cobalt deposited is small compared to the amount of gold deposited, but the cobalt content is 0.2 to 0.5% by weight. Even in this gold alloy, the hardness is remarkably improved compared to pure gold. An alloy of gold and cobalt is also preferable because of its excellent appearance and gloss.
FIG. 1 is a partial cross-sectional view of one embodiment of the electrodeposition tool of the present invention. In this figure, superabrasive grains 2 are fixed to a base metal 1 with a metal 3 such as nickel, and the metal surface is further covered with a gold alloy layer 4. FIG. 2 is a partial cross-sectional view of an electrodeposition tool in which a conventional titanium-based ceramic compound is coated by a PVD method. In this figure, superabrasive grains 2 are fixed to a base metal 1 with a metal 3 such as nickel, and the surfaces of the metal and superabrasive grains are entirely covered with a titanium-based ceramic compound layer 5. In the conventional electrodeposition tool coated by the PVD method, even the surface of superabrasive grains that are not necessary is coated, and the energy required for the coating material and coating is wasted. In the dressing tool, only the metal surface that needs to prevent chip adhesion is covered with gold or a gold alloy.
The electrodeposition tool of the present invention is less likely to be clogged because of its low adhesion to the chip on its surface, lowers the grinding resistance, improves the sharpness, extends the life of the electrodeposition tool, and is used over a long period of time. be able to. Since the surface of the electrodeposition tool of the present invention has particularly low adhesion to glass chips, it is suitable for glass grinding and can be particularly suitably used as a glass lens centering wheel.
Since the adhesion of chips can be reduced by applying gold or gold alloy plating to a tool with superabrasive grains fixed by electrodeposition, it is possible to reduce the adherence of chips. Gold or gold alloy plating can be applied to an electrodeposition tool such as a file or a hand file to improve performance and life.
[0008]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
Example 1
Using a 194D-40T-45V-30H core electrodeposition diamond wheel in which diamond abrasive grains having a particle size of 270/325 defined in JIS B 4130 are electrodeposited and fixed with nickel, a diamond alloy layer is plated with a gold alloy. The effect of was investigated. FIG. 3 is a partial cross-sectional view of the electrodeposited diamond wheel used. In this figure, a diamond abrasive grain layer 6 is formed on the outer periphery of a base 1 of a wheel made of iron (S45C).
A gold alloy was plated on the diamond abrasive grain layer under the following conditions.
Plating bath composition Gold cyanide 2.5 g / liter Potassium cyanide 30.0 g / liter Sodium diphosphate 15.0 g / liter Cobalt cyanide 10.0 g / liter Electrolysis conditions Bath temperature 50 ° C.
Current density 0.2 A / dm ²
Voltage 2V
Anode Stainless steel current flow time The thickness of the gold alloy layer plated for 20 hours was 4.0 μm, and the composition of the gold alloy was 99.7 wt% gold and 0.3 wt% cobalt.
Using this centering wheel, an optical glass lens having a diameter of 200 mm and a material BK7 was centered. The lens centering machine has a spindle horsepower of 0.75 kW, a tool peripheral speed of 1,784 m / min, and a workpiece speed of 0.2 m / min. I took it.
With the electrodeposited diamond wheel plated with this gold alloy, 2,800 optical glass lenses could be processed.
Comparative Example 1
The same electrodeposited diamond wheel as used in Example 1 was used without gold alloy plating, and the same optical glass lens as that in Example 1 was centered. When 1,200 optical glass lenses were processed, the flatness could not be reduced to 1 μm or less, and it was necessary to replace the electrodeposited diamond wheel.
When the results of Example 1 and Comparative Example 1 are compared, the electrodeposited diamond wheel of the present invention plated with a gold alloy has a life of 2.3 times or more compared to a conventional electrodeposited diamond wheel that is not plated with a gold alloy. It turns out that it has.
[0009]
【The invention's effect】
In the electrodeposition tool of the present invention, gold or gold alloy plating is further applied to the metal to which the superabrasive grains are fixed to form a gold layer or a gold alloy layer, so that the metal surface of the tool and the chips of the work material Adhesiveness is reduced and clogging is reduced, whereby the grinding resistance is lowered and the life of the electrodeposition tool is extended, so that good grinding can be performed.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view of one embodiment of an electrodeposition tool of the present invention.
FIG. 2 is a partial cross-sectional view of an electrodeposition tool in which a conventional titanium-based ceramic compound is coated by a PVD method.
FIG. 3 is a partial cross-sectional view of an electrodeposited diamond wheel used in the examples.
[Explanation of symbols]
1 Base metal 2 Superabrasive grain 3 Metal 4 Gold alloy layer 5 Titanium ceramic compound layer 6 Diamond abrasive grain layer

Claims (2)

A glass lens characterized in that a surface of a layer on which superabrasive grains of an electrodeposition tool formed by fixing superabrasive grains to a base metal by electrodeposition is fixed is further plated with 2 to 10 μm of gold or gold alloy. Wheel for centering. 2. The glass lens centering wheel according to claim 1, wherein the gold alloy is an alloy of gold and cobalt or nickel.

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