JPH11867A - Super abrasive grain tool and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the number of effective abrasive grains by forming a single recessed part or a plurality thereof by laser beam in the super abrasive grain exposed part of a grinding wheel having a super abrasive grain layer consisting of super abrasive grains mutually bonded by a bonding material, and providing a cutting edge in the corner part. SOLUTION: A recessed part 1 is formed by laser beam on a super abrasive grain surface 2 containing super abrasive grains 4 and a bonding material. The diameter D and depth H of the recessed part 1 must be 20 μm, and the diameter and depth are preferably set to 50 μm or more and 30 μm or more, respectively. According to this method, the rough grains of large super abrasive grains having a relatively low degree of collection are used, the exposed part from the bonding material is worked into a flat surface, a single recessed part or a plurality of thereof are provided on the flat surface, and a cutting edge is provided in the corner part 5 of the recessed part, whereby the number of effective abrasive grains can be increased as if it is a super abrasive grain layer surface of fine grains having a high degree of collection. The precision of a surface to be worked can be improved, and the possibility of breaking a tool by the pressurizing force is minimized since the recessed parts are mutually independent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superabrasive tool having a superabrasive layer formed by bonding superabrasive grains with a bonding material.

[0002]

2. Description of the Related Art Super-abrasive tools having a super-abrasive layer formed by bonding super-abrasive grains with a bonding material include wheels and rotary dressers. As a superabrasive layer of these superabrasive tools, a superabrasive layer bonded by a metal bond, a resin bond, or a vitrified bond is known. In addition, as a tool in which superabrasive grains are bonded in a single layer, an electrodeposition bond in which superabrasive grains are bonded only to a base metal by an electroplating method or a chemical plating method, and for diamond abrasive grains, nickel, An alloy made of cobalt or chrome or an alloy made of silver, copper, or titanium that uses the property of easily wetting the surface of diamond abrasive grains, and is bonded by a brazing material bond that directly joins the diamond abrasive grains to the base metal using this alloy It has been known.

[0003]

As a grindstone that achieves high precision and high quality processing, a porous resin bond grindstone using fine diamond has already been proposed. This grindstone aims to increase the chip pocket by the porous portion. However, in grinding where a high flatness of the finished surface is required, the above-mentioned porous resin bond grindstone having elasticity in the superabrasive layer is not necessarily sufficient, and the superabrasive having a high rigidity and a large number of effective abrasives is not always sufficient. The emergence of a superabrasive wheel with a grain layer 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 area of the surface of the superabrasive grindstone.
It is not clear how to determine the effective number of abrasive grains for the grain size and concentration of the used super-abrasive grains, and depending on the size of the used super-abrasive grains, the following problems always occur. Have.

[0005] In the case of large particles, that is, coarse particles, the surface area of the coarse particles held by the bonding material and other holding members is wide, and therefore, the holding force is strong, the coarse particles are less likely to fall off, and the flow of the grinding fluid is good. The accuracy and surface roughness of the ground surface are rough.
On the other hand, in the case of small grains, that is, fine grains, it is possible to make the precision and surface roughness of the surface to be ground finer, but the holding power of the fine grains by the holder is weak, and many fine grains fall off, and the grinding The liquid flow is poor. Therefore, it is easy to be clogged, the grinding performance is low, and the life is increased by a little superabrasive wear.

[0006] From such a viewpoint, the present applicant has previously disclosed in Japanese Patent Application No. 9-29537, increasing the number of effective abrasive grains without increasing the concentration of superabrasive grains, and using conventional coarse and fine grains. An application entitled "Superabrasive wheel and method for producing the same" has the advantages of each of the superabrasive wheels using granules.

[0007] The technical contents described above are for a grindstone having a superabrasive grain 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. Although it is intended to increase the number of effective abrasive grains for the particle diameter and degree of concentration of the superabrasive grains that had been obtained, according to subsequent studies, the present invention does not rely on the grooves formed on the surface of the superabrasive grains by a laser beam, An object of the present invention is to propose a superabrasive tool having the same effect as increasing the number of effective abrasive grains with respect to the particle diameter and the degree of concentration of the superabrasive grains.

[0008]

According to the present invention, as described above,
Instead of using superabrasive grains obtained by dividing the surface of a superabrasive grain by grooving with a laser beam, one or more concave portions by a laser beam are formed in the superabrasive grain exposed portion of the superabrasive layer. . The diameter and the depth of the concave portion need to be 20 μm or more, and preferably the diameter is 5 μm.
0 μm or more and the depth is 30 μm or more. More preferably, a concave portion is formed over the bond material exposed portion of the superabrasive grain layer and the boundary between the superabrasive grain and the bond material exposed portion.

According to this method, a large portion of superabrasive grains having a relatively low concentration is used, the exposed portion of the bonding material is processed into a flat surface, and one or more concave portions are formed on the flat surface. By providing the cutting edge at the corner portion 5 of the concave portion, it is possible to increase the number of effective abrasive grains as if the surface of a super-abrasive layer of fine grains having a high degree of concentration. If the superabrasives used are prismatic and have a flat surface from the beginning in the projection, or if the height of the exposed portion is extremely uniform, flat surface processing such as truing can be omitted.

The diameter of the concave portion formed in the exposed portion of the superabrasive layer is at least 50 μm and the depth is at least 30 μm. It is necessary in consideration of. A relatively large superabrasive grain having a substantially uniform particle size is used, and the particle size to be used is preferably 50 μm or more, and a good effect is exhibited by selecting from a range of $ 20 to $ 40. Can be.

Further, the concave portion is formed not only at the super-abrasive grain exposed portion, but also at the bond material exposed portion of the super-abrasive grain layer and the concave portion over the boundary between the super-abrasive grain and the bond material exposed portion. Thus, a super-abrasive tool with better sharpness and excellent chip discharge can be obtained. That is, it is effective that the concave portion is formed on the entire surface of the superabrasive grain layer exposed portion. In general, the opening area of the concave portion needs to be 20% or more of the total surface area of the superabrasive grain layer exposed portion.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to specific examples.

[0013]

【Example】

(Example 1) 1. Cup type wheel (6A2 type) Outer diameter 125mm, width 7mm, diamond grain size # 18 /
20 (average particle size: 900 μm) Electroplating type Wheel truing condition Remove 30μm with # 120 diamond wheel,
A flat surface was formed at the tip of the abrasive grains. 3. Wheel laser recess processing conditions and recess configuration Machine used: YAG laser Irradiation direction: Vertical direction of superabrasive layer Output: 40 W Recess diameter: 50 μm Recess depth: 30 3. 50 μm Depth interval: 100 μm (a depression is provided at the intersection of a 100 μm grid) Grinding performance confirmation test of wheel with laser concave part Grinding machine ··· Vertical shaft surface grinder Workpiece ··· Silicon single crystal In this test, the grinding resistance was reduced by 20 to 30% compared to the wheel processing without concave part.

Embodiment 2 Rotary dresser Outer diameter 80mm, width 20mm, diamond particle size # 50 /
60 (average particle size: 300 μm) Reverse plating type Laser recess processing conditions and form of recess of rotary dresser Machine used: YGA laser Irradiation direction: Irradiation in the vertical direction of superabrasive layer Output: 40 W Concave diameter: 50 μm Concave depth 2. 30 ... 50 μm Depressed pitch: 100 μm Test to confirm dress performance of rotary dresser with laser recess Grinding machine: Horizontal axis surface grinder Rotary dresser driving device: SGS-50 type manufactured by Osaka Diamond Industry Co., Ltd.
m Dress condition: Peripheral speed ratio 0.3 Cutting speed 2
mm / min

Compared with a conventional rotary dresser, the rotary dresser with a laser recess of the present invention reduced dress resistance by 20 to 30%.

FIG. 1 is a schematic sectional view of a superabrasive layer formed on a base metal. Reference numeral 1 denotes a concave portion formed on the surface of the superabrasive grain by a laser beam, 2 denotes a superabrasive layer containing a superabrasive and a bond material, 3 denotes a base metal, 4 denotes a superabrasive, and H denotes a depth of the concave portion. , D
Indicates a concave diameter. FIG. 2 is an enlarged schematic view showing a cross section of the diamond abrasive grain having the concave portion formed therein. Reference numeral 5 denotes a corner portion of the concave portion 1. At the stage of super-abrasive grain formation in the super-abrasive layer formation, finish to make the height of the super-abrasive grains uniform.
Irradiation is interrupted at a pitch of 00 μm, and a concave portion is formed while changing the position. In the first and second embodiments, a single or a plurality of concave portions are formed at the exposed end portions of the diamond abrasive grains. When the laser beam is irradiated, a recess is formed across the boundary between the exposed portion of the superabrasive grains and the exposed portion of the bond material forming the superabrasive grain layer, and a recess is formed in the exposed portion of the bond material. By forming a concave portion on the surface, an excellent superabrasive tool can be obtained.

FIG. 3 is a 50-times enlarged photograph of an upper surface of the superabrasive layer according to another embodiment, taken with an electron microscope, in which a black frame which appears in a peninsular shape from the upper portion is a superabrasive, and black is contained in the superabrasive. The concavities are apparent in the dots. The recess is also formed on the surface of the bonding material. The present invention can be applied to those using diamond abrasive grains and CBN abrasive grains.

According to the method of the present invention, a laser beam is applied to a superabrasive layer of a superabrasive tool whose sharpness has been reduced by use to form a concave portion, whereby the tool can be regenerated.

[0019]

As described above, in the present invention, relatively large-diameter diamond abrasive grains are used, and the abrasive grains are expanded mechanically and held mechanically stably by a bonding material. Since one or more independent concave portions having a diameter of 50 μm or more and a depth of 30 μm or more are provided at the tip of the abrasive layer of the abrasive layer, these concave portion forming end portions serve as cutting or wiping blades. Has the same effect as increasing the surface area, improves the precision of the surface to be processed, and since the recesses are independent of each other, the presence of these recesses causes the tool to be pressed by grinding force during grinding. It is presumed that there is little risk of breakage.

[Brief description of the drawings]

FIG. 1 is a schematic view of a cross section of a superabrasive layer of the present invention formed on a base metal.

FIG. 2 is an enlarged schematic view of a superabrasive grain cross section.

FIG. 3 is an electron micrograph enlarged photograph from the upper surface of a superabrasive layer.

[Explanation of symbols]

 1 recess 2 super-abrasive layer 3 base metal 4 super-abrasive 5 corner of recess 1 H recess depth D recess diameter

Claims (4)

[Claims] 1. A superabrasive tool having a superabrasive layer formed by bonding superabrasive grains with a bonding material, wherein one or more concave portions are formed by a laser beam on a superabrasive grain exposed portion of the superabrasive layer. A superabrasive tool characterized by being made. 2. The superabrasive tool according to claim 1, wherein the diameter and the depth of the recess are not less than 20 μm. 3. The superabrasive according to claim 1, wherein a concave portion is formed over the bond material exposed portion of the superabrasive layer and a boundary between the superabrasive and the bond material exposed portion. Grain tool. 4. A super-abrasive layer of a super-abrasive tool whose sharpness is reduced by use thereof is irradiated with a laser beam to form a concave portion. Manufacturing method of abrasive tool.