JPH07116963A - Grinding wheel - Google Patents

Abstract

PURPOSE:To reduce the weight of a grinding wheel for stabilizing its strength by applying aluminum powder metallurgy alloy consisting of aluminum alloy powder and metalloid silicon powder to the material of a core. CONSTITUTION:A segment chip 11 is adhered to a core 10 through the first adhesion layer 12, and the segment chips 11 are mutually adhered through the second adhesion layer 13 for forming a grinding stone wheel. In this case, an aluminum powder metallurgy alloy consisting of aluminum alloy powder and metalloid silicon powder is applied to the material of a core 10. The rate of silicon powder in the aluminum powder metallurgy alloy is set up to be more than 20% in weight. Thus the grinding stone wheel is very light, and its strength is stabilized, and the separation of the segment chip 11 being a grinding stone layer to the core 10 is dissolved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding wheel in which a grindstone layer is adhered to a core via an adhesive layer.

[0002]

2. Description of the Related Art Conventionally, a disk-shaped core 1 as shown in FIG.
There is a grinding wheel in which the segment chip 2 is adhered to the outer periphery of the via a bonding layer 3. Iron is used as the material of the core 1, vitrified CBN (CBN abrasive grains bonded by vitrified bond) is used as the material of the segment tip 2, and epoxy resin adhesive is used as the material of the adhesive layer. ing. Since this epoxy resin adhesive cures at a temperature of 70 to 120 degrees,
When the temperature of 0 ° C. to 120 ° C. is lowered to room temperature, the diameter change of the segment chip 2 due to the temperature is small and the diameter change of the core 1 due to the temperature is large, so that tensile stress is generated in the adhesive layer 3. Conventionally, iron is used as the material of the core 1 so that tensile stress more than the adhesive layer 3 can withstand is not generated.

[0003]

Since the iron has a large specific gravity, the weight of the grinding wheel becomes considerably large, and there is a problem that an operator has a difficulty in exchanging the grinding wheel. In order to solve this problem, it is conceivable to use an alloy made by a casting method in which aluminum and silicon are melted and molded in a mold as the material of the core 1. Although this one has a low manufacturing cost,
Since the proportion of silicon in the alloy is less than 20% by weight, there is a problem that the core 1 has a large linear expansion coefficient. If the proportion of silicon in the alloy is increased to 20% by weight or more in order to reduce the linear expansion coefficient, silicon segregates in the alloy and the silicon in the alloy is not uniformly dispersed, so that the strength of the core 1 is stable. There was a problem not to.

[0004]

The present invention has been made to solve the above-mentioned problems, and the material of the core is an aluminum powder metallurgical alloy composed of an aluminum alloy powder and a silicon powder which is a semimetal. Is. Further, the proportion of silicon powder in the aluminum powder metallurgy alloy is set to 20% by weight or more.

[0005]

The core made of aluminum powder metallurgy alloy consisting of aluminum alloy powder and semi-metal silicon powder is very light. The ratio of silicon in the alloy is 20
When the content is more than the weight percentage, the manufacturing cost is higher than that of the alloy produced by the casting method, but the segregation of silicon in the alloy is small and the silicon is uniformly dispersed in the alloy, so that the strength is stable. Further, since the coefficient of linear expansion is small, there is no risk of the grindstone layer peeling off from the core.

[0006]

Embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, reference numeral 10 denotes a disk-shaped core.
A large number of segment chips 11 are arranged on the outer periphery of 0 in the circumferential direction. A first adhesive layer 12 is provided between the core 10 and the segment chip 11, and the segment chip 11 is bonded to the core 10 by the first adhesive layer 12. In addition, the second adhesive layer 13 is provided between the segment chips 11.
And the segment chips 11 are bonded to each other by the second adhesive layer 13.

An aluminum powder metallurgy alloy is used as the material of the core 10. The chemical composition of the aluminum powder metallurgy alloy is as follows: silicon (Si) 30 weight percent, copper (Cu) 2 weight percent, magnesium (M).
g) is 1 weight percent and aluminum (Al) is 67
It is weight percent. By melting aluminum, copper, and magnesium in the high-frequency furnace 20 shown in FIG. 2 and discharging this into the space 22 through the diaphragm 21, the alloy is rapidly solidified into the aluminum alloy powder 23. By mixing a certain silicon powder, compressing it in the molds 24a, 24b, 24c shown in FIG. 3 and heating it, the core 10 made of the aluminum powder metallurgy alloy shown in FIG. 1 is produced. In the core 10 made in this way, silicon is finely and uniformly dispersed, and the strength is stable.

As a material of the segment tip 11,
Vitrified bond CBN in which CBN abrasive grains are bonded by vitrified bond is used. Segment tip 1
The grindstone layer 30 is formed by arranging 1 in the circumferential direction and adhering them to the outer periphery of the core 10. The first adhesive layer 12
As a material for the second adhesive layer 13, an industrial adhesive (epoxy resin adhesive) is used. The segment chip 11 is bonded to the outer periphery of the core 10 via an industrial adhesive, and the core 10 and the segment chip 11 are bonded together with the industrial adhesive.
By heating from 0 to 120 degrees, the industrial adhesive is cured. By cooling the first adhesive layer 12 and the second adhesive layer 13 together with the core 10 and the segment chips 11 to room temperature, a grinding wheel is produced.

The linear expansion coefficient of the segment tip 11 is 3 to 4 × 10 ^-6 (1 / degree), the linear expansion coefficient of the core 10 is 15 × 10 ^-6 (1 / degree), and the elastic modulus is Is 99
00 (kgf / mm ² ) and a specific gravity of 2.6 (g / c
m ³ ). By cooling from a state of heating from 70 degrees to 120 degrees to room temperature, the thermal displacement of the core 10 is larger than the thermal displacement of the segment chips 11, so that tensile stress is generated in the first adhesive layer 12 and each segment chip 1
When 1 shrinks, tensile stress is generated in the second adhesive layer 13. FIG. 4 is a graph showing how the linear expansion coefficient of the aluminum powder metallurgy alloy changes when the ratio of aluminum and the ratio of silicon in the aluminum powder metallurgy alloy are increased, and FIG. 5 is shown in FIG. FIG. 6 is a graph showing how the elastic modulus of the aluminum powder metallurgy alloy changes when the proportion of aluminum in the alloy is reduced and the proportion of silicon is increased. FIG. 6 shows the proportion of aluminum in the aluminum powder metallurgy alloy reduced. FIG. 7 is a graph showing how the specific gravity of the aluminum powder metallurgy alloy changes when the proportion of silicon is increased. FIG. 7 is a graph when the proportion of aluminum in the aluminum powder metallurgy alloy is decreased and the proportion of silicon is increased. What is the ratio of the elastic modulus divided by the specific gravity? It is a graph showing how to reduction.

From the above graph, the coefficient of linear expansion was determined to be 17 × 10 ^-6
In order to make it less than (1 / degree), the ratio of silicon should be 20
It should be more than weight percent. Further, when the grinding wheel is rotated at a high speed, the core 10 is centrifugally expanded to generate tensile stress in the second adhesive layer 13, and peeling occurs between the second adhesive layer 13 and the segment chip 11. In order to reduce the centrifugal expansion of the core 10 due to the high speed rotation, it is necessary to increase the ratio (= elastic modulus / specific gravity). From the above graph, in order to increase the ratio to 3380 or more, the ratio of silicon is set to 2
It should be 0 weight percent or more. When the ratio of silicon in the alloy is less than 20% by weight, the casting method alloy has a lower manufacturing cost than the aluminum powder metallurgy alloy, and the silicon is uniformly dispersed in the alloy so that the strength is improved. In comparison with aluminum powder metallurgy alloys.

If the proportion of silicon in the alloy exceeds 40% by weight, the lump of silicon in the alloy becomes large and becomes brittle, which is not suitable for the core 10. In addition, although the above-mentioned Example demonstrated the example which adhere | attached the segment tip 11 to the outer periphery of the core 1, the cup type grinding wheel which adhere | attached the segment tip 11 along the outer edge to the side surface of the core also made of aluminum powder metallurgy alloy. You may apply the core.

[0012]

As described above, according to the present invention, the material of the core is the aluminum powder metallurgy alloy consisting of the aluminum alloy powder and the silicon powder which is a semi-metal, so that it is very light. In addition, the core made of aluminum powder metallurgy alloy,
Although the manufacturing cost is higher than that of the casting alloy,
When the proportion of silicon in the alloy is 20% by weight or more, the solidified silicon in the alloy is small and the silicon is uniformly dispersed in the alloy, so that the strength is stable. Also, the coefficient of linear expansion is small, and there is no risk of the grindstone layer peeling off from the core.

[Brief description of drawings]

FIG. 1 is a front view of a grinding wheel according to the present invention.

FIG. 2 is a diagram showing a method for producing an aluminum alloy powder.

FIG. 3 is a diagram showing a method of manufacturing a core.

FIG. 4 is a diagram showing a change in a linear expansion coefficient with respect to a change in the proportion of silicon.

FIG. 5 is a diagram showing a change in elastic modulus with respect to a change in the proportion of silicon.

FIG. 6 is a diagram showing a change in specific gravity with respect to a change in the proportion of silicon.

FIG. 7 is a diagram showing a change in the ratio with respect to a change in the ratio of silicon.

FIG. 8 is a front view of a conventional grinding wheel.

[Explanation of symbols]

 10 Core 11 Segment Chip 12 First Adhesive Layer 13 Second Adhesive Layer 30 Adhesive Layer

Claims (2)

[Claims] 1. A grinding wheel in which a grindstone layer is bonded to a core via an adhesive layer, wherein the material of the core is an aluminum powder metallurgical alloy composed of aluminum alloy powder and silicon powder which is a semimetal. Grinding wheel. 2. In a grinding wheel in which a grindstone layer is adhered to a core via an adhesive layer, the material of the core is an aluminum powder metallurgy alloy consisting of an aluminum alloy powder and a silicon powder which is a semimetal. A grinding wheel characterized in that the proportion of silicon powder is 20% by weight or more.