JPH07299751A - Grinding wheel with superabrasive grain - Google Patents

Abstract

PURPOSE:To provide a grinding wheel with super-abrasive grains, whose sharpness in cutting is enhanced, which prevents dullness and fusion attachment, and produces a high precision work ground. CONSTITUTION:The grinding surface 2 of a base wheel 1 is formed from a number of projections 5 distributed uniformly and having an approx. even height, and superabrasive grains 6 are attached to the surfaces of the projections 5, and the outer surface including the abrasive grains is covered with a film of fluoric resin or silicon resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grindstone using superabrasive grains such as diamond and CBN (cubic boron nitride), which is used for grinding various materials such as plastic materials, glass materials and ceramic materials. .

[0002]

2. Description of the Related Art Compared with resin bonds, metal bonds, or vitrified bonds, these seed wheels are
Electrodeposition grindstones with high concentration of abrasive grains on the grinding surface are mainly used.

Therefore, in the grinding process, the number of abrasive grains that act on the machining is extremely large and it has a good sharpness, but on the other hand, along with the progress of the polishing, the abrasion of the abrasive grains and the discharge of the cutting chips are remarkable. There is a problem that it gets worse and easily causes clogging and welding.

In order to solve this problem, there has been proposed a rotary grindstone provided with a plurality of oblique escape grooves on the outer peripheral grinding surface as shown in Japanese Utility Model Laid-Open No. 57-3561.

[0005]

Even in the above-mentioned proposal, there is stickiness inherent to the material, for example, in the grinding process of a plastic lens, and it cannot be said that the sharpness is remarkably lowered.

In order to solve these problems, the applicant of the present invention must first form the outer peripheral grinding surface on the knurled surface according to Japanese Patent Application No. 4-30154 and Japanese Patent Application No. 4-111307. Moreover, it has been proposed to form the base metal for knurling with a material that easily wears, but depending on the material of the material to be processed, its purpose cannot be fully exerted, and there remains a problem.

[0007]

DISCLOSURE OF THE INVENTION The present invention eliminates the above-mentioned defects of conventional products and further improves the above-mentioned proposal. And, the first characteristic is that the entire surface of the polishing surface forming portion of the base metal is formed by projections uniformly distributed at a substantially uniform height, and diamond or C
This is to fix a superabrasive grain such as BN to form an abrasive surface, and to provide a film of fluororesin and / or silicon resin on the abrasive surface.

The second characteristic is that
The projection is provided on the surface of the grinding surface forming a large number of slanted grooves that are slanted at a constant pitch so as to be crossed from the left and right, or the slanted angles of the crossed left and right slanted grooves are different from each other. That is.

The third feature is that the material of the base metal is specified to be a material which is relatively easily worn by contact with the workpiece, and the protruding end of the projection is formed on a surface substantially parallel to the processed surface. It is to be.

[0010]

[Function] Since the entire surface of the base metal on which the abrasive surface is formed is formed by a large number of uniform protrusions such as knurling, the superabrasive grains are fixed to the surface of the protrusions, that is, the peaks and valleys of the protrusions by the bonding material. However, it is the superabrasive grains that are directly attached to the ridges that are directly involved in the grinding process, and the valleys are the chip pockets, and the chips fall into these pockets, which are more clogged than when the superabrasive grains are attached to a flat surface. Is reduced.

Furthermore, since a film of fluororesin and / or silicon resin is formed on the abrasive surface, the film on the outer surface of the mountain superabrasive grains directly involved in the grinding process is removed by abrasion. Grinding progresses, but the coating on the valley superabrasive grains remains with the coating on the bond material.

The fluororesin (Teflon-polytetrafluoroethylene in the example) forming the remaining film has the highest specific gravity among the synthetic resins and the smallest friction coefficient.
It does not adhere to other substances and has chemically stable properties.

Therefore, the chips falling in the chip pocket are
With this coating, it does not come into direct contact with the superabrasive grains or the bonding material, does not adhere to the periphery of the chip pocket, and is eliminated as it rotates or along the groove. If there is no coating, the chips that have fallen into the chip pocket will gradually be pressed against the superabrasive grains and the bond material and become clogged, reducing the sharpness and eventually causing welding.

Since the silicon resin has extremely strong water repellency, low adhesiveness to other substances and good releasability, it can be used in place of the above fluororesin. Further, not only one of the resins may be used, but both may be used together depending on the formation position and shape of the film.

[0015]

[Example] Fig. 1 shows a diameter of 150 mm, a shaft hole diameter of 50 mm, and a thickness of 10 mm.
Outer edge of the base metal 1 made of the steel disc (abrasive surface forming part surface)
A large number of inclined grooves 3 and 4 inclined in the circumferential direction are provided on both sides at a constant pitch from both side surfaces thereof, and the inclined grooves 3 and 4 intersecting each other are evenly arranged. It is a perspective view of the disk-shaped rotary grindstone in which the quadrangular pyramid-shaped protrusions 5 which are distributed are formed.

As shown in the enlarged cross section of FIG. 2, on the surface of the outer peripheral edge where the abrasive surface is formed, # 80 of the artificial diamond abrasive grains 6 is applied to the surface of the projection 5, that is, the portion corresponding to the peaks and valleys. However, they are fixed by the bond material 7 by nickel electrodeposition.

Further, on the outer surfaces of the fixed abrasive grains 6 and the bond material 7, there is provided a fluororesin film 8 formed by coating Teflon (trade name of Du Pont Co.).

The coating is about 300 by applying Teflon.
The coating was heated for 1 hour and left to cool, but this coating and heating may be repeated, and the thickness is preferably 5 to 30 μm.

In FIG. 3, the skew angles A and B with respect to the rotation direction of the inclined grooves 3 and 4 are set so that they are different from each other by about 10 ° around A of 45 ° (A ≠ B). As a result, the positions of the vertices of the four-sided pyramidal protrusions 5 formed between the inclined grooves 3 and 4 are displaced from each other by a slight amount with respect to the circumferential direction of the grindstone (that is, the rotating direction of the grindstone). There is.

As is apparent from the figure, of course, the grain size of the abrasive grains 6 is smaller than that of the protrusions 5, and the grains are evenly distributed in a single layer on the outer surfaces of the protrusions 5 and the valleys. A gap 9 which becomes a chip pocket is formed on the portion.

Using a cylindrical grinder with a rotating grindstone having the above-mentioned structure, a polycarbonate resin disk having a diameter of 100 mm and a thickness of 5 mm was used, a grindstone peripheral speed of 800 m / min, and a cutting speed of 0.02 to 0.03 mm / rev.
When both wet and dry grinding were performed, there was almost no welding in both grindings, and clogging was minimal.

On the other hand, in a grinding test performed with a rotating grindstone having the same size and not provided with the coating 8, clogging and welding are serious, it is difficult to continue the grinding work, and the commercial value of the processed product is significantly reduced. did.

In the grindstone of the embodiment of the present invention, at the beginning of the grinding process, the coating 8 of the abrasive grains 6 on the tops of the projections 5 is peeled off and exposed, which directly contributes to the grinding.
The valley portion surrounded by the other coating (8) plays a role of removing chips, but as the processing progresses, the abrasive grains 6 at the top of the valley are worn off and the top of the protrusion 5 of the base metal 1 is removed. Also, as shown in FIG. 4, it becomes a flat surface, and the abrasive grains 6 in the valley are sequentially floated and exposed,
Grinding will be continued.

Therefore, the base metal 1 is relatively easy to wear against a workpiece such as cemented carbide, ceramics, cement-like building material, and plastics by contacting it, steel, non-ferrous metal, alloy thereof, It is preferably composed of a non-metallic material such as plastics.

Further, by providing the projections 5 to form the abrasive surface, the distance L between the abrasive grains 6 directly involved in the grinding process with the intervals 9 between the projections 5 is such that the abrasive surface is provided on a flat surface. Since it is larger than, it has a good bite and sharpness. Considering this effect, if the tops of the protrusions 5 are previously processed into a flat surface and are formed as shown in FIG. 4 when the furnishing process is in progress, the distances L ₁ and L ₂ between the abrasive grains 6 are further increased. This may be configured from the beginning.

In the embodiment, the protrusion 5 is formed by knurling, but it may be formed by other cutting or grinding, and the coating 8 is formed by Teflon. A resin can also be used. Of course, CBN abrasive grains are used instead of diamond abrasive grains as superabrasive grains, and metal and other bond materials can also be used. Further, the present invention can be applied to not only disc-shaped grindstones but also cup-shaped grindstones and other grindstones, and if necessary, relief grooves may be provided on the grinding surface as shown in the conventional example.

[0027]

As described in the above paragraphs, the grindstone of the present invention has a grinding surface with a substantially uniform height and is formed by a large number of uniformly distributed projections, and the outer surface thereof is made of fluororesin and / or Since it is coated with a silicon resin, it has good sharpness, less clogging, and very little risk of welding. Therefore, it is possible to efficiently provide high-quality processed products with high accuracy.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a rotary grinding wheel.

FIG. 2 is a partially enlarged cross-sectional view showing a configuration of a grinding surface of an outer peripheral edge of FIG.

FIG. 3 is a partially enlarged view from the upper surface of the outer periphery showing the configuration of the inclined groove at the outer peripheral edge of FIG.

FIG. 4 is a cross-sectional view showing a state in which the top surface of the protrusion 5 of the abrasive surface of FIG. 2 is deformed into a flat surface by abrasion as the grinding process proceeds.

[Explanation of symbols]

1 Base metal 2 Abrasive surface forming part surface (abrasive surface) 3, 4 Inclined groove 5 Protrusion 6 Abrasive grain (super abrasive grain) 7 Bond material 8 Coating 9 Gap A, B Diagonal angle L, L ₁ Distance between abrasive grains L ₂ Distance between abrasive grains on top of protrusion ₂

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B24D 7/00 P

Claims (5)

[Claims] 1. The entire surface of the base metal abrasive surface forming portion is formed by a large number of projections which are evenly distributed at a substantially uniform height, and superabrasive particles having a smaller particle size than the projections are fixed to the surface of each projection. A superabrasive grain grindstone characterized by comprising a coating of a fluororesin and / or a silicon resin on all or part of the outer surface of the abrasive surface containing the fixed abrasive grains. 2. The projection is formed by a quadrangular pyramid-shaped projection formed by intersecting a plurality of inclined grooves obliquely slanting at a constant pitch on the surface of the abrasive surface forming portion from the left and right, and intersecting the inclined grooves. The superabrasive grindstone according to claim 1, characterized by being formed. 3. The superabrasive grindstone according to claim 2, wherein the oblique angles of the inclined grooves are different from each other on the right and left sides. 4. The superabrasive grindstone according to claim 1, wherein the base metal is made of a material which is relatively easily worn by contact with a workpiece. 5. The protruding end portion of the protrusion is formed on a surface substantially parallel to the processed surface, and the superabrasive grains are fixed to the valley portion of the protrusion. Super abrasive grain whetstone.