JP3375562B2 - Grinding wheel with enhanced abrasive holding power - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to diamond and CB.
The present invention relates to a grinding stone using a superabrasive grain such as N, and particularly relates to a grinding stone having improved retention of the abrasive grains.

[0002]

2. Description of the Related Art Conventionally, a grinding wheel in which superabrasive particles such as diamond particles or CBN particles are further fixed by an electrodeposition method or a brazing method has been used as a grinding and polishing wheel. Such a grinding wheel is required to have excellent sharpness and to maintain its sharpness stably for a long period of time. However, whether it is a diamond abrasive grain or a CBN abrasive grain, the sharpness and the life are shortened as the grinding work progresses.

[0003] The main reason for this is that in a grinding wheel by the electrodeposition method, the state of adherence of the abrasive grains to the base metal is unstable and the abrasive grains easily fall off, and the abrasive grain interval is small and cannot be controlled. It is possible that the cutting chips cause clogging during the grinding operation. Further, in the case of a grinding wheel by the brazing method, it may be mentioned that the abrasive grains come off due to insufficient strength of the brazing material.

As a countermeasure against this, Japanese Patent Laid-Open No. 1-205979
In the gazette, an abrasive grain is put in each mesh of a mesh member made of a non-conductive material having a mesh smaller than the grain size of the abrasive grain, and the mesh member is placed so as to be sandwiched between the abrasive grain and the base metal. Disclosed is a method for producing an electrodeposition type grindstone in which abrasive grains are temporarily attached by temporary plating while being pressed against gold, and then the mesh member is removed, and main plating is performed on the base metal, and JP-A-7-205034.
In the gazette, an adhesive is applied to one surface side of a non-conductive mesh sheet having a mesh size larger than the abrasive grains, the abrasive particles are attached to the application surface, and the adhesive application surface side is pressed against a base metal. There is disclosed a method for producing an electrodeposition grindstone in which abrasive grains are temporarily fixed between a mesh sheet and a base metal, plating is performed in this state, and then the mesh sheet is removed.

Further, in Japanese Unexamined Patent Publication No. 10-118937, one or a plurality of aggregated grains are formed in a single layer on the outer peripheral surface of a rotating substrate at intervals equal to or larger than the grain size of the abrasive grains.
A cutting grindstone fixed by a brazing material containing hard particles is disclosed.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
According to the manufacturing method described in Japanese Patent No. 5979 or Japanese Patent Application Laid-Open No. 7-205034, an electrodeposition grindstone in which abrasive grains are uniformly distributed at a predetermined interval can be obtained. However, the grindstone manufactured by such a method has an advantage that the abrasive grains can be uniformly dispersed by using a mesh sheet or a mesh body, while the abrasive grains are fixed by plating. However, there is a drawback that the holding power of the abrasive grains is insufficient.

In the cutting grindstone described in the above-mentioned Japanese Patent Laid-Open No. 10-118937, by adding hard particles to the brazing material, the abrasion resistance of the brazing material is somewhat improved, but the hard particles are Since the adhesive strength is reduced, there is no effect of increasing the holding force of the abrasive grains, and the problem of the abrasive grains falling off still remains. Further, since the distribution of the abrasive grains is non-uniform, the load on the individual abrasive grains and the supply of the coolant to the cutting point become non-uniform, and there is a problem that the stability of sharpness cannot be obtained.

The problem to be solved by the present invention is to obtain a grinding wheel in which the distribution of abrasive grains is uniform, the retaining force of the abrasive grains is excellent, and good sharpness can be stably maintained for a long period of time. is there.

[0009]

According to the present invention, in a grinding wheel using superabrasive grains such as diamond and CBN, all openings or intervals of a mesh body having openings smaller than the grain size of the abrasive grains are provided. It is characterized in that the abrasive grains are arranged in the opening, the abrasive grains are projected from the surface of the mesh body, and the mesh body and the abrasive grains are fixed to the base metal by a brazing material.

In the grinding wheel of the present invention, the distribution of the abrasive grains can be made uniform at arbitrary intervals by arranging the abrasive grains in all the openings of the mesh body or in the openings having the intervals. Further, by holding the abrasive grains to the base metal with the mesh body and the brazing material in a state where the abrasive grains are projected from the surface of the mesh body having an opening smaller than the grain size of the abrasive grains, excellent retaining force of the abrasive grains is provided. A grinding wheel is obtained.

In the present invention, the reticulate body serves to evenly distribute the abrasive grains and to function as a reinforcing material for fixing and holding the abrasive grains on the base metal. Therefore, it is desirable to use a material having excellent strength and abrasion resistance as the mesh body. As the material, titanium, titanium alloy, stainless steel, ceramics, etc. can be adopted. Titanium and titanium alloy are suitable for strengthening the retention of abrasive grains, and carbon steel is preferable from the viewpoint of workability and cost. And stainless steel are suitable. In particular, when a reticulate body made of titanium or a titanium alloy is used, carbon in the abrasive grains reacts with titanium in the reticulate body to generate titanium carbide, and a strong abrasive grain holding force is obtained.

Here, it is desirable that the amount of protrusion of the abrasive grains from the surface of the mesh body is in the range of 1/5 to 1/2 of the grain size of the abrasive grains. If this protrusion amount is smaller than ⅕ of the abrasive grain size, the portion that contributes to cutting is small and the cutting amount is small, resulting in poor sharpness. The mesh body is easily worn. Further, the impact during grinding is large, and the abrasive grains are easily damaged. on the other hand,
When it is larger than 1/2, the abrasive grain holding power of the mesh is reduced and the abrasive grains are likely to fall off. When the protrusion amount is within the above range, the abrasive grains bite into the material to be ground and are ground, and the chips are efficiently discharged, clogging and seizure do not occur, and stable sharpness is obtained. To be

Further, as the grinding wheel of the present invention, after the abrasive grains are arranged in the openings of the mesh body as described above, the mesh body and the abrasive grains are further arranged in the same manner to form a layer of the mesh body and the abrasive grains. Can also be formed in two or more layers. In this case, by arranging the outer layer abrasive grains and the inner layer abrasive grains so as not to overlap with each other, a uniform abrasive grain distribution can be obtained as a whole.
Furthermore, by forming a plurality of layers, even if the abrasive grains of the outer layer are crushed, the abrasive grains of the inner layer are projected, so that grinding can be continuously performed.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on an embodiment applied to a core bit. 1 is an overall perspective view of a core bit according to an embodiment of the present invention, FIG. 2 is a partial vertical cross-sectional view of the core bit shown in FIG. 1, and FIG. 3 is a partial plan view showing the arrangement of abrasive grains in an abrasive grain layer.

In the figure, 10 is a core bit, 12 is a cylindrical base metal forming the main body of the core bit, and this base metal 12 is
Base 12 with an outer diameter of 30 mm and a thickness of 2 mm located on the machine side
a and a bulging portion 12b located ahead of the base portion 12a and having a larger thickness than the base portion 12a. 11 attached to the bottom surface of the base portion 12a is a core bit 1
0 is a boss for attaching 0 to the rotary shaft of the machine, and the inside is hollow so that grinding fluid can be supplied.

As shown in FIG. 2, an abrasive grain layer 13 is formed on the tip surface of the bulging portion 12b of the base metal 12 and the inner and outer surfaces within a range of about 5 mm from the tip surface. The abrasive layer 13 is shown in FIG.
As shown in, the abrasive grain 16 is arranged in the opening 15 of the titanium wire net 14 having an opening smaller than the grain size of the abrasive grain 16, and the abrasive grain 16 is projected from the surface of the wire net 14 to The abrasive grains 16 are Ag-Cu-In-Ti based brazing filler metal 1
It is formed by being fixed to the inner and outer surfaces and the tip end surface of the bulging portion 12b of the base metal 12 by 7.

In this embodiment, the opening is 450 μm.
In the opening 15 of the wire net 14 having a wire diameter of 100 μm, abrasive grains 16 having a grain size of 460 to 550 μm are arranged in a zigzag pattern at intervals of one mesh, and the abrasive grains 16 are supported by the wire net 14 and the brazing material 17. It is fixed to gold 12. The protrusion amount of the abrasive grains 16 from the surface of the wire net 14 is about 130 to 175 μm, which is about 1/3 of the grain size of the abrasive grains.

By forming the abrasive grain layer 13 in this manner, the abrasive grains 16 have a uniform distribution over the entire surface of the abrasive grain layer 13, and from the surface of the wire mesh 14 having an opening smaller than the grain size of the abrasive grain 16. By brazing the abrasive grains 16 to the base metal 12 with the wire net 14 and the brazing material in a state where the abrasive grains 16 are projected, the abrasive grain layer 13 excellent in the retaining force of the abrasive grains 16 can be obtained.

FIG. 4 is a view showing a cross-sectional structure of an abrasive grain layer in another embodiment in which a mesh body and an abrasive grain layer are formed in two layers. In this embodiment, the bulging portion 12b shown in FIG.
An abrasive grain layer 23 having the same structure as the abrasive grain layer 13 is formed on the abrasive grain layer 13 on the tip surface of the. The second abrasive layer 23 is
In the first abrasive grain layer 13, the abrasive grains 26 are arranged at the positions of the wire mesh openings where the abrasive grains 16 are not arranged.
The second layer of abrasive grains 26 together with 6 and the wire net 14 are fixed to the base metal by the wire net 24 and the brazing material.

With such a two-layer structure, two
Even if the abrasive grains in the first layer are crushed, the abrasive grains in the first layer can continuously grind. Further, since the second-layer abrasive grains are arranged not only in the second-layer wire mesh opening but also in the first-layer wire mesh opening, the effect of more firmly fixing is obtained.

[0021]

EXAMPLE A core bit (invention product) of the present invention shown in FIGS. 1 and 2, and a core bit (comparative product) in which an abrasive grain layer having the basic shape shown in FIG. 1 was formed by the method described in JP-A-10-118937. ) And were used for the perforation test of concrete.

[Test conditions] Machine used: electric motor 100V, 10.5A, rotation speed 10
00 rpm Drilling method: Wet type (cooling water amount 1.5 liters / min) Drilling depth 200 mm, manually fed work material: Reinforced concrete, thickness 200 mm

[Test Results] Inventive products were excellent in the retention of the abrasive grains and did not fall off during the perforation work, and could maintain good sharpness for a long time. Drilling efficiency is about 14
At 0 (mm / min), it was about 1.3 times that of the comparative product, and the life was about 10.1 m, which was about 3 times that of the comparative product. On the other hand, the comparative product does not have sufficient holding power for the abrasive grains, and some of the abrasive grains fall off during the drilling work to lower the drilling efficiency, and the drilling efficiency is about 107
(Mm / min), the life was about 3.2 m.

[0024]

According to the present invention, the following effects can be obtained.

(1) The distribution of abrasive grains can be made uniform by arranging the abrasive grains in all openings of the mesh body or in openings having a space. In addition, by retaining the abrasive grains and the abrasive grains on the base metal with a brazing material in a state where the abrasive grains are projected from the surface of the mesh body having an opening smaller than the grain size of the abrasive grains, the retaining force of the abrasive grains is excellent. A grinding wheel is obtained.

(2) The abrasion resistance of the brazing material can be improved by fixing the mesh body in the brazing material having low abrasion resistance.

(3) By setting the protrusion amount of the abrasive grains from the surface of the mesh body within a specific range, the abrasive grains sufficiently penetrate into the material to be ground and are ground, and the chips are efficiently discharged. ,
Stable sharpness can be obtained without clogging or seizure.

(4) By forming a plurality of abrasive grain layers consisting of a net-like body and abrasive grains, even if the abrasive grains of the outer layer are crushed, the abrasive grains of the inner layer protrude, so that grinding is continued. It can be performed.

(5) By using a mesh made of titanium or a titanium alloy, carbon in the abrasive grains reacts with titanium in the mesh to generate titanium carbide, and a strong abrasive grain holding force is obtained. .

[Brief description of drawings]

FIG. 1 is an overall perspective view of a core bit that is an embodiment of the present invention.

FIG. 2 is a partial vertical cross-sectional view of the core bit shown in FIG.

FIG. 3 is a partial plan view showing an arrangement of abrasive grains in an abrasive grain layer.

FIG. 4 is a diagram showing a cross-sectional structure of an abrasive grain layer in another embodiment in which a mesh body and abrasive grain layers are formed in two layers.

[Explanation of symbols]

10 core bits 11 Boss 12 units 12a base 12b bulge 13,23 Abrasive layer 14,24 wire mesh 15 openings 16,26 Abrasive grain 17 Brazing material

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Nonoshita 210 No. Takeno, Tanamaru-machi, Ukiha-gun, Fukuoka Prefecture Noritake Diamond Co., Ltd. (56) Field (Int.Cl. ⁷ , DB name) B24D 3/06 B24D 3/00

Claims (2)

(57) [Claims] 1. A grinding wheel using superabrasive grains such as diamond and CBN, which has a mesh size smaller than the grain size of the abrasive grains.
Abrasive grains are arranged in all openings or openings of titanium or titanium alloy mesh, and the amount of projection of abrasive grains from the surface of the mesh is 1 / g of the grain size of the abrasive. 5
The abrasive grindstone is characterized in that the abrasive grains are projected from the surface of the mesh-like body so as to be in the range of 1 to 2, and the abrasive grains are fixed to the base metal by the mesh-like body and the brazing material. 2. The grinding wheel according to claim 1, wherein a plurality of abrasive grain layers made of the mesh and abrasive grains are formed.