JPH10202529A - Ultra-abrasive grain grinding wheel and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the effective number of abrasive grains and improve accuracy and surface roughness of a surface to be processed by dividing ultra- abrasive grains in an abrasive grain layer according to grooves, and forming a plurality of abrasive grain ends. SOLUTION: A diamond grain 1 has a groove 2, and a bond material 3 has a groove 4 continuous to the groove 2. The end of the groove 2 of the diamond grain becomes a cutting edge. While small cutting chips like a cutting wheel using fine grain are being generated, grinding advances. Grain 1 is retained firmly deeply against the bond material, therefore, no interference with breaking- off is made. The depth and width, number of threads, and presence of crossing of the groove, and whether a crossing angle should be made identical or different on the right and left can be selected optionally, depending upon a work, grinding conditions or the like. Where the surface of an ultra-abrasive grain layer is not flat, a flat surface is formed by truing for laser beam irradiation, thus it is not always necessary to make the grain diameter of ultra-abrasive grain uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a grindstone using superabrasives such as diamond and cubic boron nitride (CBN), and a method for producing the same.

[0002]

2. Description of the Related Art As such a kind of grinding stone, diamond, C
It is known to bond superabrasive grains such as BN with metal, resin or vitrified. Further, as a grindstone in which superabrasive grains are held in a single layer, those formed by fixing superabrasive grains on a base metal by an electroplating method are known.

[0003] In contrast to the above-mentioned electrodeposition method, for example, for diamond abrasive grains, an alloy composed of nickel, cobalt, and chrome or an alloy composed of silver, copper, and titanium is used.
There is also known a so-called brazing method in which the surface of the diamond abrasive grains is easily wetted, and the diamond abrasive grains are directly fixed to a base metal using this alloy.

As a grindstone achieving high precision and high quality processing, a porous resin bond grindstone using fine diamond has been proposed. The porous portion aims to increase the number of chip pockets.

[0005]

The above-mentioned porous resin-bonded grindstone is used for loose abrasive grain processing (lapping, polishing, etc.) conventionally used in high-precision, high-quality processing of electronic and optical parts such as computers and optical communication equipment. Is intended to be fixed abrasive processing, which is preferable in terms of efficiency in mass production, management and environment such as sludge treatment.

[0006] However, in grinding where a high degree of flatness of the finished surface is required, the above-mentioned porous resin bond whetstone having elasticity in the abrasive grain layer is not necessarily sufficient, and has high rigidity and effective grinding power. The appearance of a superabrasive grindstone provided with an abrasive layer having a large number of grains is desired.

It is said that the surface roughness of the surface to be ground is determined by the number of effective abrasive grains per unit of the grinding wheel surface. It is hard to say whether it is grasped or not, and there are always the following problems depending on the size of the used abrasive grains.

[0008] In the case of large grains, that is, coarse grains, the holding power of the abrasive grains is high, the falling of the grains is small, and the flow of the grinding fluid is good. With small grains, that is, fine grains, it is possible to increase the precision and surface roughness of the surface to be ground, but the holding power of the abrasive grains is weak and the abrasive grains often fall off, and the flow of the grinding fluid is poor.
Therefore, the grinding performance is low, and the life is extended with a little abrasive wear.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the first feature of the present invention is that each of conventional grinding wheels using fine grains and coarse grains is used. It is an object of the present invention to provide a super-abrasive grindstone based on a completely new idea, which has the advantages of the above and increases the number of effective abrasive grains without increasing the concentration of abrasive grains. As a method of realizing this, it has been created that the superabrasive grains in the abrasive grain layer are divided by grooves to provide a plurality of abrasive grain ends.

According to this method, coarse super-abrasive grains are used,
In order to align the tips of the abrasive grains, the grinding surface is processed to a flat surface by truing, a groove is formed on the flat surface by a laser beam, the superabrasive abrasive surface is divided and multiple abrasive edges are formed, as if The number of effective abrasive grains can be increased like a high-fine-grain abrasive surface. When the abrasive surface of the superabrasive layer is a flat surface from the beginning of manufacture or when used, flat processing such as truing can be omitted, and grooves may be provided by intersecting a plurality of grooves. It is preferable to make it look like a go board.

The relatively large super-abrasive grains should be of substantially uniform grain size, and the grain size used should be at least 50 μm, preferably within the range of ♯20-40. Thereby, more effects can be exhibited.

The inventors of the present invention have previously reported in Japanese Patent Application No.
No. 80227 proposes to increase the number of effective abrasive grains and the abrasive grain space by providing grooves in the superabrasive grains protruding from the surface of the bond material. However, the number of effective abrasive grains can be increased by selecting the depth and width of the groove and the angle of non-intersecting (parallel) or cross-shaped intersection by adjusting the laser beam irradiation method. It has been confirmed that the grinding performance can be obtained, and the present application has been achieved.

As the bonding material, metal or vitrified outer resin can be used. However, since the grinding layer is formed of one layer, a metal having a high bonding force is preferable. This is most effective when the flattened material is used for reprocessing.

[0014]

As described above, since the grindstone surface is formed by superabrasive grains having a relatively large particle diameter, the work surface is conventionally roughened. However, in the present invention, the superabrasive grain layer has a flat surface. Since the grooves are formed by irradiating the surface with a laser beam, a large number of abrasive grains are formed on this flat surface, and these serve as cutting or wiping blades, increasing the number of effective abrasive grains and increasing the number of effective abrasive grains. Accuracy and surface roughness are improved. On the other hand, since the diameter of the superabrasive grains used on the grindstone surface is large, the fixing of the superabrasive grains to the base metal by electroplating as described above can stably form a strong grindstone surface. The grindstone of the present invention can be dressed at the time of use or during use as needed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments will be described below with reference to embodiments.

[0016]

FIG. 1 is a schematic cross-sectional view showing the shape of a grinding surface of a grinding wheel according to an embodiment. Reference numeral 1 denotes a diamond grain having a groove 2 and 3 denotes a portion of a bonding material having a groove 4 connected to the groove 2. This whetstone was prepared as follows. Whetstone Specifications Cup type whetstone Whetstone diameter 125mm Whetstone width 7mm Diamond particles ♯18 / 20 (800-1000μm) Bonding material Ni plating Truing ♯Truing with a diamond whetstone of 120 to form a flat surface. Laser irradiation condition Input value 5KHZ Output power 2.5KW Pitch 50μm Pitch number 16-20

In FIG. 1, the flat surface length A of the diamond grain 1 is 800 to 1000 μm, the groove width B is 30 μm, the groove depth C is 14 to 18 μm, and the flat portion length A ′ between the grooves is 20 μm. Met.

FIG. 2 is a photomicrograph at 200 × magnification in which a groove is formed by irradiating the truing surface with a tangential laser beam after the truing. Irregularities appear on the flat surface of the diamond grain 1 due to irradiation.
Are formed continuously on the surface of the white bonding material 3.

The edges of the grooves of the diamond grains serve as cutting edges or rake edges to generate small chips like a grindstone using fine grains, and the grinding proceeds. Moreover, since the particles 1 are coarse and are firmly held deeply and firmly in the bonding material, no trouble is caused by falling off. The depth, width, number of grooves, presence / absence of intersection, and whether the intersection angle is the same or different between the left and right can be freely selected depending on the work, grinding conditions, and the like.

As described above, in the present invention, the configuration of the abrasive surface is made to be a specific configuration. Therefore, it is necessary that the number of superabrasive grains in the abrasive layer be one. In addition, when the surface of the superabrasive layer is not a flat surface, since the laser beam is applied after forming a flat surface by truing, the particle size of the superabrasive particles is not necessarily uniform. Is also good.

However, if the particle diameters are not substantially uniform, the number of abrasive grains that cannot form grooves on the flat surface increases, and the desired effect cannot be obtained sufficiently. Truing can be easily performed, and there is an effect that a required groove can be formed even if the amount of removal by truing is small or even in some cases without truing.

[0022]

As described above, in the present invention,
Since relatively large coarse superabrasives are used, the absolute value of the burial depth in the bond material is deeper than that using fine superabrasives. Therefore, the degree of bonding by the bonding material is strong, and the loss and dropout of superabrasive grains due to grinding are small.

Further, grooves are provided on the abrasive surface of the superabrasive layer, and the grooves are divided into a large number of uniform abrasive grains as if fine superabrasive grains were used. Particle size·
Since the number of effective abrasive grains with respect to the degree of concentration is increased, required sharpness and precision can be exhibited. In addition, the grooves can be formed into a regular or irregular shape such as a grid by irradiating the grinding surface with a laser beam.
By selecting the interval and the angle, it is possible to provide a super-abrasive grindstone having further excellent sharpness and grinding accuracy. Therefore, the grindstone of the present invention is, for example, the above-mentioned electronic, optical parts and the like free abrasive grain processing conventionally used in high-quality processing,
There are great expectations for promoting the realization of fixed abrasive processing.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a cross section of a superabrasive layer illustrating a polishing surface of an example.

FIG. 2 is a micrograph showing a state after laser beam irradiation on a polishing surface in an example.

[Explanation of symbols]

 1 diamond grains (superabrasive grains) 2 grooves of diamond grains 3 bond material 4 grooves of bond material

Claims (5)

[Claims] 1. A grindstone having an abrasive layer formed by bonding superabrasive grains with a bond material, wherein the surface of the superabrasive grain having substantially the same height as the surface of the bond material is divided by grooves, and Particle size·
A super-abrasive grinding wheel characterized by increasing the number of effective abrasive grains with respect to the degree of concentration. 2. The bonding material surface is provided with a groove connected to a groove provided on the superabrasive grain surface.
The described super-abrasive grindstone. 3. The super-abrasive grains in the abrasive grain layer are one layer and 50 μm.
3. The superabrasive grinding wheel according to claim 1, wherein particles having a substantially uniform particle size of at least m are used. 4. A super-abrasive grain layer formed by bonding super-abrasive grains with a bonding material is fixed to a base metal. 4. The method for producing a superabrasive grindstone according to claim 1, wherein a groove is formed on the surface of the bonding material. 5. The method for manufacturing a superabrasive grinding wheel according to claim 4, wherein a laser beam is irradiated after truing is performed on the abrasive surface of the superabrasive grain layer.