JP2679884B2 - Grinding wheel - 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 used for creating a shape of a workpiece by grinding.

[0002]

2. Description of the Related Art Conventionally, a grinding wheel having a structure shown in FIG. 2 has been used. In this grinding wheel, a layer in which a large number of abrasive grains 11 are dispersed and held by a binder 13 is integrally provided on a base (not shown). Each abrasive grain 11
Is made of ceramics such as silicon carbide (SiC) or alumina (Al ₂ O ₃ ) or diamond, and the inside of the binder 13 where abrasive grains 11 do not exist is generated by grinding. A large number of hollow pores 14 are provided in a dispersed manner, which serve as escape places for the chips of the workpiece to be processed.

[0003]

However, in the above-mentioned conventional grinding wheel, when the grinding wheel is soft, the abrasive grains are likely to fall off from the grinding wheel, so that the grinding wheel is greatly worn out and its life is shortened. . On the other hand, if the grinding wheel is hardened in order to prolong the life of the grinding wheel, the abrasive grains will not easily come off from the grinding wheel, which may cause crushing, and the chips of the work piece may accumulate in the gaps on the surface of the grinding wheel. Then, there is a risk that clogging may occur. When the grinding wheel is crushed or clogged, it is necessary to interrupt the grinding process and rework the grinding wheel with a dresser, or replace the grinding wheel. However, there was a problem that

The present invention has been made in view of the above problems of the prior art. When crushing or clogging occurs, the crushing or clogging is automatically eliminated without interrupting the grinding process. , To provide a grinding wheel that improves the operating rate of a grinding machine.

[0005]

In order to achieve the above object, the present invention is a grinding wheel in which abrasive grains are dispersed and held by a binder, wherein the abrasive grains are deformed at a predetermined temperature to be deformed. It is characterized in that a shape memory alloy for crushing is sealed.

Further, the binder may have pores dispersed therein.

[0007]

[Operation] As the workpiece is ground, the chips of the workpiece gradually accumulate on the surface of the grinding wheel and become clogged, or the cutting edge of the abrasive grains on the surface of the grinding wheel becomes dull. It becomes a crushed state, and the abrasive grains are difficult to crush. In such a state, the grinding resistance is large, and the surface of the grinding wheel becomes higher in temperature than that during normal grinding due to frictional heat generated between the grinding wheel and the workpiece. As a result, the shape memory alloy sealed in the abrasive grains is heated by the frictional heat and rises in temperature, and the temperature of the shape memory alloy reversely transforms into austenite phase (hereinafter referred to as deformation temperature). 2), the shape memory alloy is deformed and the abrasive grains are crushed. When the abrasive grains are crushed, the chips are peeled off from the grinding stone by the force of the crushing, eliminating clogging. Further, crushing of the abrasive grains causes a new cutting edge to be generated in the abrasive grains, thereby eliminating the clogging.

[0008]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a cross-sectional view of the surface of an embodiment of a grinding wheel of the present invention, in which (A) is a view before grinding the work piece, and (B) is the progress of grinding of the work piece. , A diagram of chips accumulated on the surface of the grinding wheel, (C) the shape memory alloy is deformed,
It is the figure which the abrasive grain crushed.

The grinding wheel of the present embodiment is formed into a predetermined shape by a layer in which a large number of abrasive grains 1 are dispersed and held by a binder 3, and a portion inside the binder 3 where the abrasive grains 1 do not exist is formed. Is provided with a large number of void-shaped pores 4 dispersed therein, which serve as escape locations for chips 5 of a workpiece (not shown) generated by grinding.

The surface of each of the abrasive grains 1 is made of ceramic such as silicon carbide (SiC) or alumina (Al ₂ O ₃ ) or diamond, and the shape memory alloy 2 is sealed therein. ing. The shape memory alloy 2 is sealed in each of the abrasive grains 1 by chemical vapor deposition such as a hot filament CVD method or a microwave plasma CVD method. Each of the shape memory alloys 2 is formed into a V shape, heated at a temperature equal to or higher than the transformation point, returned to room temperature, and then deformed into a U shape, and is bent into a U shape at room temperature. However, it has a characteristic that the shape recovers in a V shape at the deformation temperature.

As the type of each shape memory alloy 2, a Ti-50at% Ni alloy having a high versatility, a Cu-Al-Ni alloy having an excellent workability and containing Ti, and a Cu-Zn alloy are used. -Al alloy containing V and the like can be used, and it is preferable to select a shape memory alloy whose deformation temperature is higher by 20 to 50 ° C than the surface temperature of the grinding wheel obtained by calculation or experiment.

When a workpiece (not shown) is ground using the grinding wheel of the present embodiment, as shown in FIG. 1 (B), the space between the abrasive grains 1 on the surface of the grinding wheel gradually increases. The chips 5 of the workpiece accumulate and become clogged, or the cutting edge of each abrasive grain 1 becomes gradually dull and becomes a crushed state, and each abrasive grain 1 becomes difficult to crush. . In such a state, the grinding resistance becomes large, and even if a grinding liquid for cooling or lubricating the grinding part is supplied to the grinding part between the grinding wheel and the workpiece, the grinding liquid remains It becomes difficult to enter the grinding part. Therefore, frictional heat is generated on the surface of the grinding wheel, and the temperature of the surface of the grinding wheel becomes higher than that during normal grinding. As a result, the shape memory alloy 2 sealed in each of the abrasive grains 1 is heated by the frictional heat and rises in temperature, and the temperature of each shape memory alloy 2 reaches the deformation temperature of each shape memory alloy 2. Then, as shown in FIG. 1 (C), each shape memory alloy 2 recovers its shape in a V shape.

The respective abrasive grains 1 are crushed by the deformation of the respective shape memory alloys 2, and the chips 5 are peeled off from the surface of the grinding stone by the momentum at that time, so that the clogging of the grinding stone is eliminated. Further, when each of the abrasive grains 1 is crushed, a new cutting edge is generated in each of the abrasive grains 1, so that the grinding wheel is prevented from being crushed.

Since the crushing of the abrasive grains 1 occurs regardless of the hardness of the grinding stone, it is not necessary to soften the grinding stone for the purpose of preventing clogging or crushing of the grinding stone, and the grinding stone is softened. By doing so, it is possible to avoid a reduction in the life of the grinding wheel.

The above-described grinding wheel of the present invention may be one in which a layer in which a large number of abrasive grains are dispersed and supported by a binder is integrally provided on a base (not shown), a round wheel or a ring wheel. Various shapes such as a grindstone can be formed according to the purpose of use.

Further, since the chips are peeled off from the grinding stone by the crushing of the abrasive grains, it is not always necessary to provide pores in the binder.

Further, the shape of the shape memory alloy sealed in the abrasive grains is not limited to the above-mentioned shape, and can be freely selected within a range in which the abrasive grains can be crushed by the deformation of the shape memory alloy.

[0019]

Since the present invention is configured as described above, it has the following effects.

By enclosing a shape memory alloy in each abrasive grain, which deforms when the temperature reaches a predetermined temperature and crushes each of the abrasive grains, crushing or clogging occurs in the grinding stone and the surface of the grinding stone When the temperature becomes high, the shape memory alloy in the abrasive grains on the surface of the grinding stone deforms and crushes the abrasive grains, and a new cutting edge appears in the abrasive grains, eliminating clogging of the grinding stone. can do. Further, since the chips accumulated on the surface of the grinding stone are separated from the grinding stone by the crushing of the abrasive grains, the clogging of the grinding stone can be eliminated.

Further, since the crushing of the abrasive grains occurs regardless of the hardness of the grinding stone, it is not necessary to soften the grinding stone for the purpose of preventing the grinding stone from being crushed or clogged, and the life of the grinding stone is shortened. Can escape the decline.

Further, since the crushing and clogging of the grinding grindstone is eliminated as described above, the grinding grindstone is interrupted during the grinding process, and it is not necessary to adjust the grinding grindstone or replace the grindstone. Since the grinding process can be continuously performed, the operating rate of the grinding machine can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the vicinity of the surface of an embodiment of a grinding wheel of the present invention, (A) is a view before grinding a workpiece, (B)
FIG. 4C is a diagram in which the workpiece is ground and chips are accumulated on the surface of the grinding wheel, and FIG. 7C is a diagram in which the shape memory alloy is deformed and the abrasive grains are crushed.

FIG. 2 is a cross-sectional view near the surface of a conventional grinding wheel.

[Explanation of symbols]

 1 Abrasive grain 2 Thermal shape memory alloy 3 Binder 4 Pore 5 Chip

Claims (2)

(57) [Claims] 1. A grinding wheel in which abrasive grains are dispersed and held by a binder, wherein a shape memory alloy that deforms and crushes the abrasive grains at a predetermined temperature is sealed in the abrasive grains. Grinding wheel to do. 2. The grinding wheel according to claim 1, wherein pores are dispersed in the binder.