JP2011083857A - Method of manufacturing grindstone core and method of manufacturing grindstone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for inexpensively manufacturing a high quality aluminum grindstone core having a high content ratio of silicon such as more than 20 wt.% and an efficient manufacturing method of a grindstone having a grindstone segment bonded to an outer periphery of the grindstone core. <P>SOLUTION: In the manufacturing method of the substantially disk shaped grindstone core 1 used for the grindstone rotated on a rotating shaft of the grindstone, as a material of the grindstone core, aluminum (Al) including 20 wt.% or more (or 30 to 40 wt.%) of silicon (Si) is used to cast the grindstone core 1 by using a semi-solid die-casting method. When the grindstone core is cast by using the semi-solid die-casting method, a plurality of grooves M are formed on an outer peripheral surface of the grindstone core 1. The grooves M are filled with adhesive agent and the grindstone segment is bonded thereon to manufacture the grindstone. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a grindstone core cast from an alloy of aluminum (Al) and silicon (Si), and a grindstone production method for producing a grindstone by attaching a grindstone segment to the grindstone core.

In recent years, a rotating grindstone used in a grinder or the like is generally configured by attaching a grindstone segment containing abrasive grains to the outer peripheral surface of a substantially disc-shaped metal grindstone core.
Conventionally, the material of a grindstone core is manufactured by forging a steel bar mainly composed of iron (Fe). In the case of a grindstone core having a diameter of several tens [cm], the main component is iron. Therefore, the weight is large. For this reason, workability | operativity at the time of conveyance and replacement | exchange of a grindstone is bad, and weight reduction is calculated | required also from viewpoints, such as energy efficiency.

As a light weight approach, a method of replacing the material with a material lighter than iron can be considered. When aluminum is used as a lighter material than iron, aluminum has a larger coefficient of linear expansion than iron, so that the grindstone core is centrifugally expanded more than the case of iron due to high-speed rotation of the grindstone. For this reason, when grinding is performed with such a grindstone, there is a problem that processing accuracy is lowered.
Therefore, silicon (Si) is contained in order to reduce the linear expansion coefficient of aluminum, but in order to obtain a linear expansion coefficient equivalent to that of iron, silicon is contained in a proportion of 30 to 40% by weight. There is a need. The eutectic point in the alloy of aluminum and silicon is that the silicon content is 12.6% by weight.

As described above, as disclosed in Patent Document 1 and Patent Document 2, a method of sintering an alloy powder is employed as a method for manufacturing a grindstone core having a high silicon content (higher than the eutectic point). Yes.
In addition, although it is as a machine part different from a grindstone core, the manufacturing method of the aluminum alloy containing 9 to 13 weight% of silicon is disclosed by patent document 3. FIG.

Japanese Patent Laid-Open No. 7-171767 JP-A-8-257717 Japanese Patent Laying-Open No. 2005-089827

Since the grindstone core manufactured by the prior art described in Patent Document 1 and Patent Document 2 has a linear expansion coefficient close to that of iron, high-precision processing can be performed by grinding using this. However, since aluminum and silicon alloy powder is sintered while being pressed with a large press or the like, a very large press machine is required when manufacturing a grindstone core having a diameter of several tens [cm]. Further, in the method of pressure sintering powder, bubbles are generated inside and cannot be completely eliminated, so that there is a problem that strength is lowered.
The present invention has been made in view of the above points, and it is an object of the present invention to provide a manufacturing method capable of manufacturing a high-quality aluminum grindstone core having a high silicon content exceeding 20% by weight at a low cost. And It is another object of the present invention to provide an efficient method for producing a grindstone in which a grindstone segment is bonded to the outer periphery of the grindstone core.

As means for solving the above-mentioned problems, a first invention of the present invention is a method for manufacturing a grindstone core as set forth in claim 1.
The method for producing a grindstone core according to claim 1 is a method for producing a substantially disc-shaped grindstone core used for a grindstone that is rotated around a grindstone rotation axis. The grindstone core is cast using a semi-solid die casting method using aluminum (Al) containing Si).

The second invention of the present invention is a method for manufacturing a grindstone core as set forth in claim 2.
The method for producing a grindstone core according to claim 2 is a method for producing a substantially disc-shaped grindstone core used for a grindstone rotated around a grindstone rotation axis, and the material for the grindstone core is 30 wt% or more and 40 wt%. The grindstone core is cast using a semi-solid die casting method using aluminum (Al) containing no more than% silicon (Si).

The third invention of the present invention is a method for manufacturing a grindstone core as set forth in claim 3.
The method for producing a grindstone core according to claim 3 is the method for producing a grindstone core according to claim 1 or 2, wherein the outer peripheral surface of the grindstone core at the time of casting using the semi-solid die casting method. A plurality of grooves are formed in.

A fourth invention of the present invention is a method for manufacturing a grindstone as set forth in claim 4.
The method for producing a grindstone according to claim 4 is a method for producing a grindstone using a grindstone core cast by the method for producing a grindstone core according to claim 3, and is formed on the outer peripheral surface of the grindstone core. A method of manufacturing a grindstone comprising the steps of filling a groove with an adhesive and attaching a grindstone segment containing abrasive grains on the groove filled with the adhesive.

  If the method for producing a grinding stone core according to claim 1 or 2 is used, in the aluminum containing silicon, the silicon content is the eutectic point by casting using a semi-solid die casting method. Even when it exceeds 20% by weight, which is larger than 6% by weight, it is not a molten state in which a liquid phase and a solid phase are mixed, but is cast by using an alloy in a butter state (semi-solid state). A uniform casting can be produced without the need for a pressing machine.

  In addition, according to the method for manufacturing a grindstone core according to claim 3, the groove shape of the outer peripheral portion, which has been difficult to fill the mold with the material by the conventional general forging pressure or pressure sintering method, is realized. can do.

  Moreover, according to the manufacturing method of the grindstone of Claim 4, the quantity (thickness) of the adhesive at the time of affixing a grindstone segment is filled by filling an adhesive into the groove | channel formed in the outer peripheral part of the grindstone core. Management can be facilitated, stable quality can be obtained, manufacturing time can be further shortened, and a grindstone can be manufactured efficiently.

It is a figure explaining the example of the external appearance of the grindstone core cast using the manufacturing method of the grindstone core of this invention. It is a figure explaining the outline of a semi-solid die-casting method. It is a binary system equilibrium state diagram of aluminum and silicon. It is a figure explaining sticking of the grindstone segment TS to the grindstone core.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. FIG. 1 shows an example of a schematic external view (perspective view) of a grindstone core 1 cast using the “method for producing a grindstone core” of the present invention, and FIG. 2 is a schematic explanatory view of a semi-solid die casting method. is there. FIG. 3 shows an example of a binary equilibrium diagram of aluminum and silicon. (A) region is a liquid phase, (B) region is a liquid phase + solid phase (aluminum solid phase), (C) The region indicates the liquid phase + solid phase (silicon solid phase), and the region (D) indicates the solid phase.

● [External appearance of cast stone core 1 (Fig. 1) and outline of semi-solid die casting method (Fig. 2)]
A grindstone core 1 cast by the semi-solid die casting method described in the present embodiment is a grindstone that is used by being rotated around a grindstone rotation axis by a grinder or the like, and has a substantially disc shape. Moreover, it casts using the alloy of aluminum (Al) containing 30 to 40 weight% of silicon (Si) as a material. By containing 30 to 40% by weight of silicon, the linear expansion coefficient can be made equivalent to iron (Fe). Further, by using aluminum as a main component, it is possible to realize a significant weight reduction as compared with the case of using iron as a main component.

The grindstone core 1 described in the present embodiment is also characterized by the shape at the time of casting.
When the silicon content is 30 to 40% by weight, which is higher than the eutectic point of 12.6% by weight, the temperature is set in the vicinity of the general 680 ° C., and the molten metal is poured into the mold by forging and casting. In this method, the molten metal is in a mixed state of a liquid phase (liquid aluminum and silicon) and a solid phase (particulate solid silicon), so that the molten metal is likely to be non-uniform, and the groove M formed in the outer peripheral portion of the grindstone core 1. It was very difficult to sufficiently fill the molten metal into the shape. In the case where the silicon content is 30 to 40% by weight, since it becomes the (C) region in the equilibrium diagram shown in FIG.
Even if the silicon content is 30 to 40% by weight, if the molten metal is set to 900 ° C. or higher, it is possible to obtain a uniform molten metal only in the liquid phase. It is not preferable because time is increased, working efficiency is lowered, and mold durability is also lowered.
Moreover, since silicon is 30 to 40% by weight, segregation of silicon occurs unless the liquid phase is quenched. In order to quench the liquid phase, it is necessary to quench the mold, but it is very difficult to quench the mold. Therefore, when silicon is contained in a proportion of 30 to 40% by weight, it is very difficult to produce a uniform cast product.
Further, even if the pressure sintering method is used, it is very difficult to perform pressure sintering while sufficiently filling the shape of the groove M serving as the end of the mold with an aluminum-silicon alloy powder.

In the present application, as shown in the schematic diagram of FIG. 2, a semi-solid material is formed by pushing a butter (semi-solid) material into a mold space K formed by the molds S1 and S2 with a piston P or the like at high pressure. The grindstone core 1 is cast using a solid die casting method.
By using this method, even if the silicon content is 30 to 40% by weight, the mold space K can be filled with the material uniformly. Therefore, the grooves M formed in the outer peripheral portion of the grindstone core 1 are formed. It can be formed appropriately at the time of casting. Moreover, it is not necessary to set the temperature at 900 ° C. or higher so that silicon does not become a solid phase.

[Procedure for attaching the grindstone segment 20 to the grindstone core 1 (FIG. 4)]
Next, with reference to FIGS. 4A to 4C, a procedure for manufacturing a grindstone by attaching a grindstone segment to the grindstone core 1 in which the groove M is formed in the outer peripheral portion will be described.
Conventionally, for example, a CBN grindstone having a very high hardness is manufactured by attaching a grindstone segment containing CBN abrasive grains to the outer peripheral surface of a grindstone core with an adhesive.
In the conventional manufacturing method, since it was very difficult to form grooves on the outer peripheral surface of the grindstone core at the time of forging or sintering, the outer peripheral surface was flat.
Therefore, conventionally, fine irregularities are first formed on the outer peripheral surface of the grindstone core by shot blasting or the like.
Then, as shown in FIG. 4 (D), the Tegs TG is fixed to the outer peripheral surface of the grindstone core, the adhesive A is applied so as to have the same uniform thickness as the diameter R of the Tegs TG, and the grindstone segments are pasted. It was attached. As described above, conventionally, it has been very troublesome to make the thickness of the adhesive A uniform.

On the other hand, since the grindstone core 1 described in the present embodiment can form the groove M on the outer peripheral surface at the time of casting, it is not necessary to perform shot blasting.
In the first step, as shown in FIG. 4A, the groove M is filled with the adhesive A.
Further, it is not necessary to control the thickness of the adhesive A using Teggs TG or the like as in the prior art, and the adhesive A is filled so as to be almost the same height as the convex portion around the groove M (a ground state) Therefore, the adhesive A can be filled in the groove M in a short time and stably.
In the next step, as shown in FIG. 4 (B), a grindstone segment TS containing abrasive grains is pasted on the outer peripheral surface of the grindstone core 1 (the grindstone from above the groove M filled with the adhesive A). Paste segment TS).

In the above description, the example in which the simple plate-shaped grindstone segment TS is curved and pasted along the shape of the outer peripheral surface of the grindstone core 1 has been described.
Next, an example in which the shape of the grindstone segment TS is a special shape will be described with reference to FIG. The grindstone segment TS shown in FIG. 4 (C) has notches at both ends in the circumferential direction of the grindstone core 1 on the inner circumference side of the grindstone segment TS so as to fit to adjacent convex portions N in the grindstone core 1. Is formed.
Adhesive A is applied to groove M at an appropriate thickness (excess adhesive is pushed out from the periphery when grindstone segment TS is fitted). And the notch part of the grindstone segment TS is fitted between the adjacent convex parts N, and a grindstone is manufactured.
The structure shown in FIG. 4C has an effect that the strength in the circumferential direction of the grindstone segment TS is higher than the structure shown in FIG.

As described above, in the method for manufacturing a grindstone core and the method for manufacturing a grindstone described in the present embodiment, an example in which aluminum having a silicon content of 30 to 40% by weight is used as a material has been described. In the semi-solid die casting method described above, it is sufficiently possible to cast aluminum having a silicon content of 20% by weight or more as a material.
Moreover, even if it is a large grindstone core which requires a very large press machine etc. by pressure sintering, cost can be suppressed, without requiring a large installation. Moreover, there is no generation of internal defects (bubbles) that are likely to occur in the pressure sintering method, and sufficient strength can be ensured.
Furthermore, since the outer peripheral groove M, which has been very difficult to form by conventional forging and pressure sintering methods, can be formed at the time of casting, when a grindstone segment is pasted using an adhesive. It is possible to make the adhesive application (filling) step in a shorter time.
As described above, the weight of the grindstone core 1 mainly composed of aluminum having a linear expansion coefficient equivalent to that of the conventional grindstone core composed mainly of iron can be reduced to about 1/3.

The method for producing a grindstone core and the method for producing a grindstone according to the present invention are not limited to the procedures and processes described in the present embodiment, and various modifications, additions, and deletions are possible without departing from the scope of the present invention. It is.
The dimension of the groove | channel M formed in the outer peripheral surface of the grindstone core 1 can be set to various dimensions, such as several hundred [μm] to several [mm].
The method for producing a grindstone core of the present invention is not limited to a grindstone core, and can be applied to various cast products.
Further, the above (≧), the following (≦), the greater (>), the less (<), etc. may or may not include an equal sign.

1 Grindstone core A Adhesive M Groove N Protrusion TS Grinding stone segment

Claims (4)

A method of manufacturing a substantially disc-shaped grindstone core used for a grindstone rotated about a grindstone rotation axis,
As the material for the grindstone core, aluminum (Al) containing 20% by weight or more of silicon (Si) is used,
Casting the grinding stone core using a semi-solid die casting method,
A method for manufacturing a grinding wheel core. A method of manufacturing a substantially disc-shaped grindstone core used for a grindstone rotated about a grindstone rotation axis,
As the material for the grindstone core, aluminum (Al) containing 30 wt% or more and 40 wt% or less of silicon (Si) is used,
Casting the grinding stone core using a semi-solid die casting method,
A method for manufacturing a grinding wheel core. It is a manufacturing method of a whetstone core according to claim 1 or 2,
At the time of casting using the semi-solid die casting method, a plurality of grooves are formed on the outer peripheral surface of the grindstone core,
A method for manufacturing a grinding wheel core. A method for producing a grindstone using a grindstone core cast by the method for producing a grindstone core according to claim 3,
Filling the groove formed in the outer peripheral surface of the grindstone core with an adhesive; and
A method for producing a grindstone comprising a step of attaching a grindstone segment containing abrasive grains from above a groove filled with an adhesive.

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