JPS5925832B2 - glass polishing tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polishing tool for polishing glassy optical elements such as lenses, prisms, filters, etc.

Generally, the process of polishing optical elements such as lenses and prisms includes shaping using a curve generator, sanding or diamond pellet processing using a casting plate, and pitch polishing.

Among these methods, polishing involves attaching lenses or prisms, etc. to an attachment plate, and polishing the lenses, etc. attached to the attachment plate using a cast polishing plate with a pitch, but in the case of polishing using this method To do this, the surface of the pitch must be properly machined into a curved or flat surface, but it has not been easy to form an accurate surface. Furthermore, since high-speed polishing is not possible, it also has the disadvantage of requiring a long polishing time. In addition to polishing using this pitch, polishing with sheets such as those with a CEO2 sheet on the surface of a cast metal polishing plate, and polishing with a polishing plate with a polyurethane sheet on a cast metal plate. A method of polishing using CEO2 etc. dissolved in water has also been used. However, polishing using these methods does not allow high-speed polishing and also has problems with the durability of the polishing plate. For this reason, glass polishing tools have recently been developed that use diamond powder dispersed in synthetic resins such as polyurethane resins, polyimide resins, and epoxy resins. Also known is a glass polishing tool made of a polyimide resin mixed with carbon fiber to increase the hardness of the resin, and a suitable amount of diamond powder mixed therein. If a glass polishing tool containing diamond powder mixed in these resins is used, polishing can be performed at a faster speed and the polishing power can be improved by 20 to 40% compared to polishing methods using pitch. Therefore, the polishing time can also be shortened to some extent. However, it is not possible to further improve the polishing ability, and there is a limit to the polishing power. Especially when polishing hard glass, no improvement in efficiency can be expected. Due to the above circumstances, the abrasive power is further improved by dispersing diamond powder in the synthetic resin layer, and the hardness of the resin layer is 110 to 12 on the Rockwell M scale.
A polishing tool has been developed in which a polishing plate with a diameter of 0 is provided on the surface of the polishing plate.

A polishing tool having such a layer allows stable high-speed polishing, and the tool is highly durable; however,
Lenses with a large curvature, that is, a small radius of curvature, have the following disadvantages. In general, as this type of lens polishing tool undergoes polishing work, diamond powder and the like separate from the surface of the tool, causing clogging and reducing cutting efficiency. However, when this encroachment phenomenon occurs, the frictional force increases, causing the unnecessary diamond powder surface that is causing the encroachment to peel off, exposing a new diamond powder surface inside (this is a phenomenon known as self-growth). ) will occur. This self-propagation effect facilitates good polishing work. In the case of a polishing tool in which diamond powder is mixed into the resin layer of the above-mentioned hardness, if the radius of curvature is large, the unnecessary diamond powder will be washed away by the polishing liquid, etc., as described above. However, when polishing a deep lens with a small radius of curvature, the self-generating effect does not occur and polishing defects are likely to occur because the unnecessary diamond powder is difficult to flow. The present invention focuses on the hardness of the resin to provide a polishing tool that has greatly improved polishing power and can satisfactorily polish even deep lenses with a small radius of curvature.

As shown in the drawings, the polishing tool of the present invention has a layer 2 formed on the surface of a plate 1 made of cast metal or the like, in which 20% to 60% by weight of diamond powder is dispersed and mixed in resin. 2 has a hardness of 95 to 110 on the Rockwell M scale. Note that 3 is a lens to be polished. In this way, the aforementioned Rockwell M Scale 110
By using a slightly softer resin layer than the resin layer with a hardness of ~120, unnecessary diamond powder can be easily peeled off from the surface of the resin layer, thereby allowing better polishing work. This is what I did. As the lens 3 to be polished, a lens with a small radius of curvature used in optical instruments is suitable.

For example, it can be applied to lenses used in cameras, ophthalmic instruments, measuring instruments, projectors, microscopes, endoscopes, optical pickups, and the like. The resin layer whose hardness falls within the above range may be, for example, a phenol resin, an unsaturated polyester resin, or an epoxy resin mixed with an appropriate amount of diamond powder, or a resin layer containing cobalt or calcium in addition to the diamond powder in the above resin. , copper, etc. can be considered as the main ingredient.

According to the experimental results, the hardness of the synthetic resin is 100.4, 103.5, 105.7, and 1 on the Rockwell M scale, respectively.
All of the glass polishing tools of the present invention in which a predetermined amount of diamond powder was mixed into the resin layer of No. 07.6 were capable of good polishing.

Also, the polishing speed with the above polishing tool is within 1 minute for precision grinding.
The polishing time is 5 minutes and the total time is about 6 minutes. Conventionally, for example, one lens with a small radius of curvature, which is used in the optical instruments mentioned above, is pasted on a sticking plate and polished using a pitch polishing plate. When processing, sanding takes 4 to 5 minutes and polishing takes 30 minutes, totaling about 35 minutes, resulting in an efficiency improvement of about 550%. Furthermore, it is 110 on the Rockwell M scale.
It has been confirmed that when diamond powder is dispersed and mixed into a synthetic resin with a hardness exceeding 100 mL, polishing defects occur when polishing lenses with a small radius of curvature due to the influence of the unnecessary diamond powder mentioned above. On the other hand, if the synthetic resin is softer than 95 on the Rockwell M scale, the abrasive power will decrease.For example, an experiment using a synthetic resin with a hardness of 84.5 on the Rockwell M scale mixed with diamond powder showed that Polishing power is 1/5 to 1/8
It declined to . If the hardness of the synthetic resin is too soft as described above, it is not preferable because the effect of high-speed polishing, which is one of the objects of the present invention, cannot be obtained. As explained above, according to the polishing tool of the present invention, the polishing ability can be significantly improved compared to conventional tools, and even when applied to polishing lenses with a small radius of curvature, the polishing tool does not become impossible to polish and is excellent. Polishing is possible.

The abrasive tool of the present invention has the hardness described above as Rockwell M.
Compared to synthetic resins with a scale of 110 to 120, they are slightly less durable, but to improve this point and extend the life of the polishing tool, you can mix in an appropriate amount of metal powder such as copper. .

This is because diamond has a weak adhesion to resin, but metals such as copper have strong adhesion to resin, so it is possible to prevent the diamond powder from falling off more than necessary without impairing the above-mentioned self-growth effect. This is thought to be due to the

[Brief explanation of drawings]

The drawing is a sectional view of the tool of the present invention. 1... Polishing plate, 2... Resin layer mixed with diamond powder, 3... Lens.

Claims (1)

[Claims] 1 Diamond powder is added to a resin with a hardness of 95 to 110 on the Rockwell M scale at a weight ratio of 20% to 60.
A glass polishing tool for polishing lenses with a small radius of curvature and having a surface made of a material with % dispersion.