JP3039112B2 - Whetstone for precision grinding and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding wheel for precision grinding which is excellent in dispersibility of abrasive grains and has a large chip pocket as compared with abrasive grains, and a method for producing the same.

[0002]

2. Description of the Related Art Generally, a general metal-bonded grindstone is prepared by uniformly mixing abrasive grains with a powdered metal binder, embedding the mixed powder with a base metal, compacting and sintering them. It is manufactured.

[0003]

However, it is difficult to uniformly disperse the individual abrasive grains at the time of mixing and embedding the abrasive grains and the binder in the above-described method of manufacturing a metal bond whetstone. In addition, it is inevitable that the distribution density of the abrasive grains varies within the abrasive grain layer after sintering. For this reason, there is a defect that the arrangement of the abrasive grains exposed on the grinding surface is uneven and the sharpness of the grinding wheel is locally uneven, and the grinding performance is unstable.

When grinding is performed using a conventional metal bond grindstone, as shown in FIG. 8, abrasion proceeds from the abrasive grain layer 5 which is relatively softer than the abrasive grains 2, and the chip pocket 9 is removed. Then, chips are discharged by the tip pocket 9. However, there was a dissatisfaction that the tip pocket 9 could not be made sufficiently large compared to the size of the abrasive grains.

The present invention has been made in view of the above circumstances, and has a uniform distribution density of abrasive grains, hardly causes local unevenness in sharpness, and can form a chip pocket sufficiently larger than the size of the abrasive grains. An object of the present invention is to provide a grinding wheel for precision grinding and a method for manufacturing the same.

[0006]

According to a first aspect of the present invention, there is provided a grinding wheel for precision grinding, wherein a large number of abrasive grains are arranged along a shell-like virtual surface in a metal bonding phase and the shell-like virtual surface is formed . Inside
The means for solving the problem is that abrasive grain collection parts whose parts are filled with a metal phase are dispersed at a certain interval from each other.

In the method of manufacturing a grinding wheel for precision grinding according to the present invention, a large number of abrasive grains having a relatively small diameter are fixed directly to the surface of solid metal particles forming a metal phase by friction pressure welding. After that, a metal coating layer was further formed on the outer periphery to form composite particles, and the composite particles were subjected to pressure molding and sintering to produce a grindstone.

[0008]

[Action] A relatively small-diameter abrasive grain is directly pressure-bonded to a surface of solid metal particles forming a metal phase by a friction welding coating method and fixed in large numbers. When a layer is formed to form composite particles, and the composite particles are subjected to pressure molding and sintering, a large number of abrasive grains are arranged along an imaginary surface in a shell shape.
And the inside of the shell-like virtual surface is filled with a metallic phase.
Abrasive collecting portion that is allowed to dense, it is possible to obtain a grindstone in a metal binder phase are dispersed at regular intervals.
Therefore, according to such a grindstone, the distribution density of the abrasive grains is rough.
That it can be uniformly dispersed without creating
Moni, in Ken Kezutoki, the central portion of the abrasive grain collecting portion
Since the compacted metal phase wears in the same manner as the metal binder phase, a large chip pocket can be reliably and uniformly formed in comparison with the abrasive grain size, and good chip discharge performance can be obtained.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a grinding wheel for precision grinding according to the present invention.

FIG. 1 is a schematic view showing an embodiment of a grinding wheel for precision grinding according to the present invention. The grindstone for precision grinding includes an abrasive grain gathering portion 3 coated with abrasive grains 2... Along a surface (virtual surface) A of a solid spherical metal core particle 4 and an outer peripheral surface of a grindstone (not shown). Are dispersed in the metal bonding phase 1 provided at a constant interval from each other. Therefore, on the abrasive grain collecting part 3
Inside the virtual plane A, a metal phase composed of the metal core particles 4 is provided.
It is compacted.

The metal core particles 4 include Cu, Ni, A
l and the like are preferred. The metal core particles 4 have a particle size of 1
It is preferably about 0 to 500 μm, particularly 30 to 100 μm
Is more preferable. If it is less than 10 μm, when the abrasive grains 2 are coated along the surface of the metal core particles 4, the metal core particles 4 are unlikely to become the central nucleus, and if it exceeds 500 μm, it becomes difficult to coat the surface of the metal core particles 4.

As the abrasive grains 2, super abrasive grains such as diamond and cBN, and general abrasive grains such as SiC and Al ₂ O ₃ can be used. The particle size of the abrasive grains 2 is desirably 50 μm or less for precision grinding, but may be appropriately changed according to the purpose of use. The shape of the abrasive grains 2 is preferably a regular polyhedron or a spherical shape close to a spherical shape. However, irregular abrasive grains may be used as long as they are not extremely scaly.

The metal constituting the metal bonding phase 1 is C
u, Ni, Al, Sn, Co and the like are preferable. The particle size of the metal powder used to form the metal binding phase 1 is:
The thickness is preferably 0.1 to 20 μm for manufacturing reasons described later.

[0014] In such a precision grinding stone, is abrasive grain 2 ... it is coated along the metal core surface of the particles 4 in spherical Rutotomo
The inside of this surface is formed by a metal phase composed of metal core particles 4.
The abrasive aggregates 3 that are densely packed with each other are dispersed in the metal bonding phase 1 at regular intervals.
During grinding, the metal phase in the central part of the abrasive aggregate 3
It wears in the same manner as the metal bonding phase 1, and a chip pocket having a diameter larger than the diameter of the abrasive grains 2 is uniformly formed. For this reason,
The chip discharge performance becomes extremely good.

FIG. 2 is a schematic view showing a second embodiment of a precision grinding wheel according to the present invention. This grinding wheel for precision grinding also has a virtual inside of a metal bonding phase 1 provided on the outer peripheral surface of a grinding wheel (not shown).
It is arranged abrasive grains 2 along the plane A Rutotomoni this virtual face A
Are obtained by dispersing abrasive grain gathering portions 3 whose interiors are filled with a metal phase at regular intervals.

In this example, the virtual
The difference from the first embodiment is that the metal phase in plane A is formed of the same metal as metal bonding phase 1. In this grinding wheel for precision grinding, not only the same operation and effect as in the first embodiment are exerted, but also the metal phase filled in the virtual plane A is made of metal.
Since they are the same metal as binder phase 1, they wear
Chip pockets are more uniform,
Reliable chip discharge can be encouraged.

Next, a method of manufacturing the grinding wheel for precision grinding of the first embodiment will be described. First, solid materials such as Cu, Ni, Al
The abrasive grains 2 having a relatively smaller diameter than the metal core particles 4 are directly pressed along the surface of the metal core particles 4 by the friction welding coating method.
And coat many . In order to coat the abrasive grains 2 by the friction welding coating method, an apparatus as shown in FIG. 3 is used.

The structure of the pressure rolling device shown in FIG. 3 will be briefly described. In the figure, reference numeral 10 denotes a cylindrical drum whose axis is set horizontally, and is rotated about the axis. A fixed shaft 12 is arranged inside the drum 10 along an axis, and the shaft 12 has a pressing arm 1 facing downward.
3, and a scraping arm 14 extending obliquely downward on the rear side in the rotation direction is fixed. Drum 10
After the metal core particles 4 and the abrasive grains 2 are added to the inside, the inside of the drum 10 is substantially sealed by closing with a lid (not shown).

At the lower end of the pressure arm 13, a pressure plate 15 having an arc shape parallel to the inner surface of the drum 10 is fixed, and a certain gap is formed between the pressure plate 15 and the inner surface of the drum 10. ing. On the other hand, the lower end of the scraping arm 14 is shaped like a blade, and is configured to scrape off powder adhered to the inner surface of the drum 10.

To perform pressure bonding, first, the metal core particles 4
And the abrasive grains 2 are put into the drum 10 at a predetermined ratio.

Next, the above-mentioned mixed powder is put in the drum 10 and capped, and then the drum 1 is rotated. Then, the mixed powder is pressurized in the gap between the pressing plate 15 and the drum 10 and rubbed against each other while rolling motion is applied to the mixed powder. Metal nuclei particles 4 which are mechanically energized and collided
Since the metal core particles 4 of the abrasive grains 2 are softer and smaller in diameter, the abrasive grains 2 are driven into the entire surface of the metal core particles 4.

The powder adhering to the inner surface of the drum 10 is again dispersed by the scraping arm 14, and the non-adhered abrasive grains 2 are again driven into the surface of the metal core particles 4 by the pressing arm 13. By repeating this operation for a certain period of time, the abrasive grains 2 are successively press-coated on the surface of the metal core particles 4, and finally, as shown in FIG. .

Next, Cu, Ni, Al,
A metal powder such as Sn or Co is charged, and the drum 10 is rotated in the same manner as described above, so that Cu, Ni, A
A metal coating layer 6 made of 1, Sn, Co, or the like is formed (see FIG. 5). The particle size of the metal powder used to form the metal coating layer 6 is desirably 0.1 to 20 μm. If the thickness is less than 0.1 μm, the metal powder alone causes agglomeration or a sufficient pressure is not applied to the metal powder, so that it is difficult to form the metal coating layer 6. If it exceeds 20 μm, the thickness distribution of the metal coating layer 6 becomes non-uniform or the formation of the metal coating layer 6 itself becomes difficult.

The metal coating layer 6 improves the sinterability when turning into a grinding stone, which will be described later. The thickness of the metal coating layer 6 is desirably about 1 to 30 μm. This is 1
If it is less than μm, it does not serve a sufficient sintering aid at the time of firing, and if it exceeds 30 μm, it becomes difficult to form.

In order to form the metal coating layer 6 on the abrasive grain gathering portion 3, not only the above method but also an electroless plating method, an electroplating method or the like may be used.

Next, the composite particles 7 thus obtained are
Is molded together with the base metal, compacted and sintered. Then, the metal coating layers 6 of the composite particles 7 are easily bonded to each other. As a result, as shown in FIG. 6, a metal binding phase 1 in which the metal coating layers 6 are firmly bonded to each other is formed. at the same time,
Solid metal core particles 4 coated with abrasive grains 2
The metal phase is dispersed three-dimensionally at substantially equal intervals, and forms a metal phase as a part of the metal bonding phase 1 of the base metal. Note that the above-mentioned compacting and sintering include a hot press method and the like.
The atmosphere for molding and sintering can be in the air, but an inert or reducing atmosphere is more preferable.

The shapes of the base metal and the abrasive grain layer to be used may be any shapes conventionally used in practice. Also,
A grindstone in which the whole grindstone is composed only of the abrasive grain layer without using a base metal can also be manufactured. Pressing conditions and heating conditions during molding may be the same as those in the related art.

According to the above-mentioned grinding wheel manufacturing method, a large number of fine abrasive grains 2 are uniformly arranged in a shell shape around the above-mentioned metal phase composed of metal core particles 4 to form a grinding wheel dispersed in the binder phase 1. be able to. For this reason, at the time of grinding, since the metal phase composed of the metal core particles 4 relatively softer than the abrasive grains is easily worn, a chip having a larger diameter than the diameter of the abrasive grains 2 as shown in FIG. The pocket 8 can be formed, and the chips can be efficiently discharged including the chip pocket due to the abrasion of the binder phase 1. Moreover, these metallic phases
And the metal binding phase 1 wear in the same way.
Chip pockets are not unevenly formed.
It is possible to more reliably improve the chip discharge performance. Therefore, the grinding power can be reduced, and good sharpness can be maintained.
In addition, according to this method, there is no occurrence of deflection of the abrasive grains which has conventionally occurred at the time of molding. In addition, in the grindstone obtained by this method, fine abrasive grains are uniformly dispersed in the abrasive phase in the same pattern, so the sharpness of the ground surface is good, and the finished surface roughness of the material to be ground is lower than before. It is improved about twice. Further, the abrasive grains 2 are coated by the friction welding coating method.
By being directly driven into the surface of the metal core particles 4
The abrasive grains 2 are pressed and fixed, so that the abrasive grains 2 are removed during sintering.
Dropping or metal bonding in the metal bonding phase 1 of the manufactured grinding wheel.
A layer harder than the combined phase 1 and the above metal phase is left,
It does not hinder the formation of the ket.

In the above-described method for manufacturing a grinding wheel,
Various fillers may be added to the metal powder. In that case, it is possible to impart a function according to the filler type to the formed grinding wheel. For example, if carbon powder is mixed with metal powder as a filler, the carbon powder is gradually supplied to the ground surface when the finally obtained grinding wheel is used for grinding, so lubricity and spontaneous generation of abrasive grains The blade action can be enhanced. In addition, a part or all of the metal coating phase 6 is made of Si.
If hard particles such as C and Al ₂ O ₃ are added, the filler can be uniformly arranged around the individual abrasive grains 1 inside the bonding layer. It can be provided effectively.

In the present embodiment, the method of manufacturing the grinding wheel for precision grinding shown in FIG. 1 has been described. However, by using the same metal for the metal core particles 4 and the metal coating phase 6, the method can be easily performed. The grinding wheel for precision grinding of the second embodiment shown in FIG. 2 can be manufactured.

[0031]

As described above, in the grinding wheel for precision grinding according to the present invention, a large number of abrasive grains are arranged along the imaginary surface in the form of a shell in the metal bonding phase, and the inside of the imaginary surface of the shell is formed.
The abrasive grains are densely dispersed by a metal phase, and are dispersed at a constant interval from each other, so the fine abrasive grains are uniformly dispersed in the same pattern, and the sharpness is good and the finished surface roughness is the same as that of a conventional grindstone. It is about twice as much as the one performed. During grinding, the metal phase in the central part of the abrasive aggregates
Since the metal binder phase is worn in the same manner, a chip pocket having a large diameter compared to the abrasive grain size can be formed reliably and uniformly, and good chip discharge performance can be obtained. For this reason, grinding power can be reduced, and good sharpness can be maintained.

In the method of manufacturing a grinding wheel for precision grinding according to the present invention, a relatively small number of abrasive grains are directly pressed against the surface of solid metal particles forming a metal phase by a friction welding coating method to fix a large number of them. after, further by forming a metal coating layer to the composite particles on the outer periphery thereof, so to produce a grinding wheel and the composite particle pressing and sintering, ensures grindstone effects described above can be obtained
And it can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a first embodiment of a precision grinding wheel according to the present invention.

FIG. 2 is a schematic view showing a second embodiment of the precision grinding wheel of the present invention.

FIG. 3 is an explanatory view of an apparatus used for the method of manufacturing a grinding wheel for precision grinding according to the present invention.

FIG. 4 is a schematic view showing an abrasive grain collecting part.

FIG. 5 is a schematic view showing a composite particle.

FIG. 6 is a schematic view showing an example of a grinding wheel for precision grinding of the present invention.

FIG. 7 is a schematic view showing a tip pocket of the grinding wheel for precision grinding of the present invention.

FIG. 8 is a schematic view showing a tip pocket of a conventional grindstone.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal bonding phase 2 Abrasive grain 3 Abrasive grain gathering part 4 Metal core particle

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Naoto Oikawa 246-1 Egoshi, Kurosuno, Izumi-cho, Iwaki-shi, Fukushima Prefecture Mitsubishi Materials Corporation Iwaki Works (56) References JP-A-56-102477 (JP, A) JP-A-51-100167 (JP, A) JP-A-50-7194 (JP, A) JP-A-60-46837 (JP, A) Jiko 61-7219 (JP, Y2) (58) (Int.Cl. ⁷ , DB name) B24D 3/06 B24D 3/00

Claims (2)

(57) [Claims] To 1. A metal binder phase, the virtual face of Rutotomoni the shell-like arranged multiple abrasive grains along the imaginary surface forming a shell-like
A grinding wheel for precision grinding, characterized in that abrasive grain collection parts whose interiors are filled with a metal phase are dispersed at a certain interval from each other. 2. A relatively small-diameter abrasive grain is directly pressure-bonded to a surface of solid metal particles forming a metal phase by a friction welding coating method.
After fixing a large number of these, a metal coating layer is further formed on the outer periphery to form composite particles, and the composite particles are subjected to pressure molding and sintering to produce a grinding wheel. Production method.