JP2000006029A - Manufacture of vitrified grinding wheel with resin core part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vitrified grinding wheel having a resin core part of a high strength whose strength is improved further. SOLUTION: Since the material of a core part regulated by mixing an aggregate in which an oxidized silicon type glass is fixed to the surfaces of inorganic particles and a specific resin material in the core regulation process 28, is hardened in the core hardening process 40 in the condition to fill to the inner side of an outer peripheral grinding wheel in the flowing-in process 30, the resin core part including the above aggregate is fixed to the inner side of the outer peripheral grinding wheel. Since the above oxidized silicon type glass has a high affinity with the resin and the combination force of the aggregate and the resin is improved, a vitrified grinding wheel with a high strength of core part is obtained. Since the core part is fixed to the inner side of the outer peripheral grinding wheel by hardening the fluid core material, a high adhesive strength is obtained without using an adhesive, so as to make the vitrified grinding wheel with the core part in a further higher strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a vitrified grindstone having an outer grindstone portion composed of a vitrified grindstone structure and a resin core portion exclusively supporting the outer grindstone portion.

[0002]

2. Description of the Related Art A vitrified grindstone is uniformly formed from an inner peripheral portion to an outer peripheral portion, for example, by a vitrified grindstone structure in which abrasive grains are bonded by an inorganic binder. Alternatively, it is constituted by impregnating a synthetic resin into the inner periphery of an outer peripheral grindstone portion made of a vitrified grindstone structure and reinforced.

[0003]

However, the conventional vitrified grinding wheel as described above cannot always obtain sufficient strength in high-speed grinding, for example, and cannot withstand rotation during grinding. For example, recent high-speed grinding such as 3600-4800 m / min
When high-speed grinding is performed, the conventional vitrified grinding wheel usually deals with a porous and soft-bonded vitrified grinding wheel structure, but as the demand for high-speed grinding increases, the high strength required for the core part is increased. Therefore, the strength of the core was a bottleneck.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vitrified grinding wheel having a high-strength core portion or a supporting portion with further improved strength.

The inventors of the present invention have made various studies based on the above circumstances, and as a result, it has been found that an abrasive having a number of 120 or less, preferably coated with silicon oxide glass, is used as an aggregate and a heat-resistant material such as epoxy resin. Core parts bonded to each other and the inside of the outer peripheral grindstone part by the curable resin, or at least the abrasive material whose fluidity has been enhanced by being coated with a phenol resin in a semi-cured state is mutually connected with the phenol resin. It has been found that the use of a core portion bonded to the inside of the outer peripheral grindstone portion provides a significantly higher strength than a conventional vitrified grindstone. The present invention has been made based on such findings.

[0006]

First Means for Solving the Problems That is, the first means
The gist of the invention is to provide a vitrified grinding wheel having a resin core for exclusively supporting the outer grinding wheel portion inside an outer grinding wheel portion made of a vitrified grinding wheel structure in which abrasive grains are bonded by an inorganic binder. A manufacturing method, wherein (a) an adjusting step of adjusting the material of the core part by mixing an aggregate and a predetermined thermosetting resin, and (b) adjusting the core part adjusted by the adjusting step A filling step of filling a material inside the outer peripheral grindstone part, and (c) a core part for fixing the core part inside the outer peripheral grindstone part by curing the material of the core part filled in the filling step. And a curing step.

[0007]

According to the first aspect of the present invention, the core material adjusted by mixing the aggregate and the predetermined thermosetting resin is cured while being filled inside the outer peripheral grindstone portion. Thereby, the resin core portion including the aggregate is fixed to the inside of the outer peripheral grindstone portion. By hardening the material of the core part, the core part is fixed inside the outer peripheral grindstone part, so that high adhesive strength can be obtained without using an adhesive, so that the vitrified grindstone having the core part has higher strength. Is done.

[0008]

Another aspect of the first invention Here, the first invention preferably further comprises a step of preparing an aggregate having silicon oxide glass adhered to the surface of the inorganic particles. By doing so, the silicon oxide glass adhered to the surface of the inorganic particles has a high affinity for the resin, and the bonding force between the aggregate and the resin is increased, so that the vitrified grinding wheel having a high-strength core portion. Is obtained.

[0009] Preferably, the aggregate is a particle made of silicon carbide or alumina having a grain size of 120 or less. In this way, a vitrified grindstone with higher strength can be obtained.

Preferably, in the adjusting step, the liquid resin is mixed within a range of 20 to 50 parts by weight with respect to 100 parts by weight of the aggregate. In this way, a suitable fluidity of the mixture of the aggregate and the liquid resin can be obtained within a range that does not reduce the strength of the grindstone after curing, so that a decrease in yield due to insufficient flow and a decrease in adhesive strength of the core portion are prevented. Is done.

[0011] Preferably, the method further includes the step of generating a grinding wheel waste powder and granule for generating, as the aggregate, a grinding wheel waste powder obtained from the vitrified grindstone after firing. A fluid mixed fluid is adjusted by mixing the material powder and the liquid epoxy resin, and in the filling step, the mixed fluid is poured into the outer peripheral grinding stone portion. In this way, there is an advantage that industrial waste such as used vitrified whetstones can be reused and contribute to environmental conservation.

Preferably, the core hardened in the core hardening step has a bending strength (flexural strength) of 300 kg / cm ² or more and an elastic modulus of 500 kg / mm ² or more. is there. In this way, a vitrified grindstone having a strength capable of rotating at high speed can be obtained.

[0013]

A second aspect of the present invention for achieving the above object is to provide an outer peripheral grindstone portion comprising a vitrified grindstone structure in which abrasive grains are bound by an inorganic binder. Inside, a method of manufacturing a vitrified grinding wheel having a resin core portion exclusively for supporting the outer peripheral grinding wheel portion, wherein (a) a predetermined resin material is coated on the surface of the aggregate at least in a semi-cured state A step of preparing a resin-coated sand to which high fluidity has been imparted, and (b) a filling step of filling the resin-coated sand prepared by the step inside the outer peripheral grindstone portion, and (c) the filling And a step of curing the core portion filled in the step to fix the core portion inside the outer peripheral grinding stone portion.

[0014]

According to the second aspect of the present invention, the resin-coated sand provided with high fluidity by coating the surface of the aggregate with the predetermined resin material at least in a semi-cured state is formed inside the outer peripheral grindstone portion. The resin core portion containing the above-mentioned aggregate is fixed to the inside of the outer peripheral grindstone portion by being cured in a state of being filled. The resin-coated sand has a high fluidity and easily penetrates into the unevenness of the inner peripheral surface of the outer peripheral grindstone portion, so that the fixing strength between the outer peripheral grindstone portion and the high-strength vitrified grindstone is increased. can get.

[0015]

Another aspect of the second invention In the second invention, preferably, the aggregate is a particle made of silicon carbide or alumina having a particle size of No. 150 or less. In this way, a vitrified grindstone with higher strength can be obtained.

Preferably, the aggregate is a powder of grinding stone waste obtained from a fired vitrified grinding wheel. In this way, there is an advantage that industrial waste such as used vitrified whetstones can be reused and contribute to environmental conservation.

Preferably, the resin material is a thermosetting resin such as a phenol resin, and the resin-coated sand is mixed with a thermosetting resin of the same type as the thermosetting resin such as a phenol resin powder. It includes steps. With this configuration, the resin powder of the same type as the resin that coats the aggregate is contained in the resin-coated sand, so that the mutual bonding force of the resin-coated sand is increased, and the strength of the core portion after curing is further increased. .

Preferably, in the resin-coated sand, the surface of the aggregate is coated with 1 to 10 parts by weight of a phenol resin based on 100 parts by weight of the aggregate. In this way, the resin coated sand can have a suitable fluidity within a range that does not reduce the strength of the grindstone after curing, so that a decrease in yield due to insufficient flow and a decrease in adhesive strength of the core portion can be prevented.

Preferably, in the filling step, the resin-coated sand is pressurized when filling the resin-coated sand. By doing so, the filling of the resin-coated sand in the inner peripheral side space of the outer peripheral grindstone portion becomes uniform and the filling density is increased, so that a decrease in yield due to insufficient flow and a decrease in the adhesive strength of the core portion are further prevented.

Preferably, in the core part curing step, the resin-coated sand is coated by heating the resin-coated sand filled by flowing and pressurizing the inner peripheral space of the outer peripheral grindstone part. The thermosetting resins are mutually bonded and cured. By doing so, the resin-coated sand constituting the core portion becomes denser by being connected to each other, thereby increasing the strength, and further increasing the bonding force with the inner peripheral surface of the outer peripheral grindstone portion.

Preferably, the core part cured in the core part curing step has a bending strength (flexural strength) of 300 kg / cm ² or more and an elastic modulus of 500 kg / mm ² or more. is there. In this way, a vitrified grindstone having a strength capable of rotating at high speed can be obtained.

[0022]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a vitrified grinding wheel 10 according to an embodiment of the present invention. This vitrified whetstone 10
Has an outer peripheral grindstone portion 12 composed of a vitrified grindstone structure in which abrasive grains are combined with an inorganic binder to exclusively grind a workpiece, and the outer peripheral grindstone portion 12 is exclusively supported on the inner peripheral side thereof. For this purpose, a resin supporting portion, that is, a core portion 14 is fixed. The vitrified grindstone structure of the outer peripheral grindstone portion 12 is well known, and is made of silicon carbide (SiC) or fused alumina (A).
abrasive grains or abrasives such as l ₂ O ₃ )
It is a porous structure which is bound by a vitreous inorganic binder (vitrified bond) containing O ₂ ) or the like as a main component and in which numerous continuous or discontinuous pores are formed. In such a structure, at the time of grinding, the abrasive grains on the grinding surface that comes into sliding contact with the work are appropriately crushed or fall off, and the cutting edge of the abrasive grains is suitably regenerated.

The resin core 14 is made of silicon carbide (SiC) or fused alumina (Al ₂ O ₃ ).
A general abrasive such as B ₄ C or TiC, or a material in which a glass material containing silicon oxide (SiO ₂ ) as a main component is fixed to part or all of the surface thereof is used as an aggregate, and the aggregate is weight ratio. The liquid epoxy resin containing 60% or more of the resin is cured to have a high strength.

FIG. 2 shows a main part of a manufacturing process of the vitrified grinding wheel 10. In the figure, in a grindstone raw material adjusting step 20, a raw material of the outer peripheral grindstone portion 12, for example, general abrasive grains such as silicon carbide or fused alumina, and silicon oxide (S
An inorganic binder (vitrified bond) composed of a mixture of silica powder, feldspar powder, clay, glass frit and the like for forming a vitreous material containing iO ₂ ) as a main component and a certain amount of mutual cohesion during molding. A binder such as dextrin to be generated and a pore-forming agent such as walnut powder or inorganic balloon mixed as required are mixed at a predetermined weight ratio. For example, 6 parts by weight of an inorganic binder, 6 parts by weight of walnut powder, and 2 parts by weight of water are well known with respect to 94 parts by weight of WA (white alundum) having a particle size of 60 as the abrasive grains. Mixed by a mixer. In the following grinding wheel portion forming step 22, the mixed raw material is filled in a molding die and pressurized at a relatively high pressure by a press machine to form an annular wheel portion 12 as shown in FIG. A molded body is obtained integrally. Next, in a grindstone part firing step 24, the annular shaped body is sintered and sintered at a firing temperature of, for example, 1300 ° C. in a firing furnace to form an outer peripheral whetstone part 12 having a vitrified whetstone structure. . The chemical components of the inorganic binder include, for example, 60% of SiO ₂ , 20% of Al ₂ O ₃ ,
Na ₂ O ₃ 5%, K ₂ O 5%, CaO 3%, Mg
O 2%, B ₂ O ₃ 5%, silicon oxide SiO ₂
Is a main component.

In the aggregate refining step 26, silicon carbide (Si
C) quality or fused alumina (Al_TwoO _Three) Polishing such as quality
Silicon oxide (Si)
O_Two) Whose main component is vitreous
The finished powder is refined as aggregate. Silicon carbide or molten aluminum
Silicon oxide (SiO_Two)
If the vitreous material is fixed, for example,
Vitrified whetstone or chipping defect with small diameter
Vitrification after firing that failed the inspection due to a defective method, etc.
In the finishing step 42 after firing
Such as finishing powder (fan powder) discharged as shavings
By crushing and classifying stone waste,
For example, it can be obtained as aggregates of No. 80, No. 100, No. 120
You. For example, in the above shaving powder, the abrasive grains are about 87.5% by volume.
And the inorganic binder (vitrified bond) is 1
It is about 2.5% by volume. At this time, as aggregate
The abrasive grains used have substantially the same strength and coefficient of thermal expansion.
For example, if it is an alundum system, WA,
Mixture of PA (pink alundum) and A (alundum)
May be.

Next, in the core part raw material adjusting step 28,
A binder, which is preferably a thermosetting liquid resin, is added to the above aggregate at a predetermined ratio. For example, aggregate 10
50 parts by weight of liquid epoxy resin is added to 0 parts by weight. Thereafter, by mixing them with a well-known mixer, a fluid core portion raw material is prepared. In the filling step, that is, in the pouring step 30, the fluid core part raw material adjusted in the core part raw material adjusting step 28 is, as shown in FIG. By being poured into the inner peripheral side of the grindstone section 12, the inner peripheral side space is filled. FIG. 3 shows an outer peripheral grindstone positioned so as to be concentric with a columnar mandrel 38 erected vertically on a horizontal base 36 by inclining a mixing container 34 containing a core material 32. A state is shown in which the core portion raw material 32 is poured into the inner peripheral side of the portion 12 by using its fluidity until it reaches a depth equal to or slightly larger than the thickness of the outer peripheral grindstone portion 12.

Subsequently, in the core part curing step 40, the curing conditions of the liquid resin contained in the core part raw material 32 are adjusted, so that the core part raw material 32 poured into the inner peripheral side of the outer peripheral grindstone part 12 is cured. At the same time, they are coupled to each other and also to the inner peripheral surface of the outer peripheral grindstone portion 12. For example, if the liquid resin contained in the core portion raw material 32 is a room temperature curing type, the liquid resin is held at room temperature, and if the liquid resin is a high temperature curing type, it is held for a preset curing time in an oven set at the curing temperature. Core part raw material 32
When a liquid epoxy resin is used for
A curing temperature of 0 ° C is used.

Then, in the finishing step 42, the outer peripheral whetstone 1
The surface of the vitrified grindstone 10 in which the core material 32 poured into the inner peripheral side of the hardened core 2 is hardened is removed by a depth of about 1 to 2 mm using a dressing tool or a cutting tool. Ten outer diameters, roundness, thickness, and the like are adjusted. In the whetstone part forming step 22 and the pouring step 30, the outer peripheral whetstone part 12 and the core 1
4 is molded.

Through the above-described steps, a resin core portion obtained by mixing and hardening an outer peripheral grindstone portion 12 using PA and 100 parts of an # 120 alundum-based finishing powder by mixing 50 parts of a liquid epoxy resin. (Outer diameter 400mmφ) 14, outer diameter 610mmφ × 32mmt × inner diameter 304.8mm
When the vitrified grindstone 10 of φ is manufactured, its composition and strength are obtained, for example, as shown in FIG. 4, and its fracture rotational strength is obtained, for example, as shown in FIG. The comparative example is a vitrified grindstone having the same dimensions as the vitrified grindstone similar to that of the outer peripheral grindstone portion using PA. The vitrified grindstone 10 manufactured by the process of the present embodiment corresponds to the sample 4 in FIG. 6, and as shown in FIG. 4, the bending strength is almost twice that of the comparative example (the same structure as the outer grindstone portion). (45MP
a) was obtained, and as shown in FIG.
Or higher. Further, since the finished powder, which is industrial waste, is used as the aggregate of the core portion 14, the industrial waste is reused, and there is an advantage that it can contribute to environmental conservation.

Samples 1 to 7 in FIG. 6 show the results of an experiment in which the above steps were used and the mixing ratio of the abrasive material and the liquid resin was changed. Here, as the values for obtaining the effect of the present invention described above, the bending strength (flexural strength) of the core portion 14 is 300 kg / cm ² or more and the elastic modulus is 50%.
0 kg / mm ² or more is required, and those values are reference values. As is clear from the samples 1 to 7 in FIG. 6, the sample 1 in which the particle size of the aggregate made of silica sand is No. 1000 has a bending strength and an elastic modulus lower than the above-mentioned reference values, but the sample 2 has
As shown in Sample 7, a silicon carbide or alumina aggregate, or a silicon carbide or alumina aggregate (shavings) having silicon oxide glass adhered to the surface thereof has a particle size of 120.
If it is less than or equal to the number, the bending strength and the elastic modulus are sufficiently higher than the above-mentioned reference values, and it is clear that the strength of the vitrified grindstone 10 that can sufficiently withstand rotation during high-speed grinding or heavy grinding is obtained. Particularly, as shown in Samples 4 to 7, as the aggregate, the higher the silicon oxide glass adhered to the surface, the higher the affinity with the liquid resin such as the epoxy resin. Was done. Further, when the liquid resin is mixed in the range of 20 to 50 parts by weight with respect to 100 parts by weight of the aggregate, sufficient strength can be obtained, but the lower the weight ratio of the liquid resin, the higher the strength. However, if the amount of the liquid resin is less than 20 parts by weight, the fluidity of the core part raw material 32 is lost and the workability is reduced. If the amount is more than 50 parts by weight, the aggregate is insufficient and sufficient strength cannot be obtained.

Next, another embodiment of the present invention will be described. In the following description, portions common to the above-described embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

FIG. 7 shows another example of a process for manufacturing the vitrified grinding wheel 10. In the figure, in the coated sand manufacturing process 50, the aggregate of No. 150 or less, preferably No. 60 to 120, refined in the aggregate refining process 26, that is, silicon carbide abrasive grains, fused alumina abrasive grains, or a mixture thereof Aggregate 1 is applied to the surface of inorganic particles (for example, grinding stone waste known as finishing powder) having silicon oxide glass (an inorganic binder of a grinding stone) fixed to part or all of the surface.
By coating a phenolic resin, which is a thermosetting resin at a weight ratio of 1 to 10 with respect to 00, in a semi-cured state, the fluidity is reduced until the drop speed of the JISR6126- 1970 test method becomes 30 g / sec or more. Enhanced resin-coated sand is produced. With this semi-cured state, in order to increase the fluidity at the time of filling in a range in which sufficient molding bonding and bonding force are compensated by pressure and heating described below,
After the liquid phenol resin is coated on the surface of the aggregate, it is cured, that is, the polymerization is appropriately advanced so as to have an appropriate molecular weight, and sand-like fluidity is imparted. The resin coated on the inorganic particles is, for example, a solution obtained by dissolving novolak obtained by reacting formaldehyde with phenol in alcohol and adding a necessary amount of hexamethylenetetramine, and coated on the inorganic particles by a cold coating method. .

Next, in the adjusting step 52, the same system as that coated on the aggregate so as to have a preset value within the range of 10 to 30 parts by weight with respect to 100 parts by weight of the resin-coated sand. A relatively dry powdery or thermosetting resin, or a phenolic resin, which is a powdery thermosetting resin, is added to a resin-coated sand and mixed therewith, whereby a fluid core material is adjusted. You. The powdery phenol resin is, for example, a fine powder, and if added in excess of 30 parts by weight, the fluidity of the resin-coated sand is impaired.

In the filling step 54, in the same state as that shown in FIG. 3, the core material having fluidity adjusted in the adjusting step 52 is mixed with the annular outer periphery fired in the grinding stone part firing step 24. By being poured into the inner peripheral side of the grindstone part 12, the inner peripheral side space is filled,
By being pressed with a relatively small pressure of about 1 to 60 kg / cm ² by a press device, the core material is homogenized and densified in the inner peripheral side space of the outer peripheral grindstone portion 12 and the outer peripheral grindstone portion 12 is pressed. Resin-coated sand whose surface is coated with a semi-cured phenolic resin while being cut into the inner peripheral wall surface is mutually bonded to some extent.

In the subsequent core part curing step 56, the curing conditions of the phenol resin, which is a coating resin in a semi-cured state of the resin-coated sand, are adjusted, so that the resin-coated sand is cured in the inner peripheral space of the outer peripheral grindstone 12. The core portion 14 having a sufficient strength is formed by being hardened in a state of being densely filled, and by bonding the resin coated sands to each other and to the inner peripheral surface of the outer peripheral grindstone portion 12. For example, the core part curing step 5
In No. 6, the resin-coated sand densely filled in the inner peripheral side space of the outer peripheral grindstone portion 12 is held at a curing temperature of 200 ° C. for a relatively short curing time of about 5 to 15 minutes, for example. You. In some cases, the temperature may be maintained at about 150 ° C. for about 1 to 2 hours thereafter. Then, in the finishing step 42, the surface is finished after the resin-coated sand is cured, whereby the vitrified grindstone 10 shown in FIG. 1 is obtained.

When the vitrified grindstone 10 is manufactured through the above-described steps, as shown in FIG. 2, a liquid resin or a fluid core material 3 containing the same is used.
It is not necessary to handle 2 in a manufacturing operation, and it is only necessary to perform a work of pouring a powdery resin-coated sand or a press work for suppressing the same, so that the work is facilitated and the working environment is greatly improved. Further, since the amount of resin used for bonding the aggregate in the core portion 14 is relatively small, the strength of the core portion 14 can be easily obtained, and the time for hardening the core portion 14 is relatively short. There is the advantage of time. Also, the central grain of the resin-coated sand, that is, the core portion 14
In this case, there is an advantage that the industrial waste can be reused and contribute to environmental conservation.

Samples 8 to 11 shown in FIG. 6 are used to form a high-strength core portion 14 by filling and hardening a resin-coated sand in the inner peripheral side space of the outer peripheral grindstone portion 12 by the above process. The results of experiments when the material of the abrasive or the aggregate is changed are shown. here,
As described above, as the values for obtaining the effects of the present invention, the bending strength (flexural strength) of the core portion 14 needs to be 300 kg / cm ² or more and the elastic modulus 500 kg / mm ² or more. Is the reference value. As is clear from Samples 8 to 11 in FIG. 6, Sample 8 using aggregate (particle size: 80) made of silica sand
Is less than the above-mentioned reference values in bending strength and elastic modulus, but as shown in Samples 9 to 11, aggregates of silicon carbide or alumina, or alumina aggregates having silicon oxide glass adhered to the surface thereof When (milling powder) (grain size 80) is used, the strength of the vitrified grindstone 10 that can sufficiently withstand rotation during high-speed grinding or heavy grinding can be obtained because the bending strength and the elastic modulus sufficiently exceed the above reference values. Became clear. In particular, as shown in Sample 11,
As the aggregate, the higher the silicon oxide glass adhered to the surface, the higher the affinity with the phenol resin, and thus the higher the strength. Although data is not shown, a thermosetting resin and a thermosetting resin powder used to cover the surface of the aggregate in a range of 1 to 15 parts by weight with respect to 100 parts by weight of the aggregate are used. In this case, a sufficiently favorable strength can be obtained. If the weight ratio of the thermosetting resin is too low, the bonding strength is reduced, and it becomes difficult to obtain the strength of the core portion 14. Even if the weight ratio of the thermosetting resin is too high, the aggregate is insufficient and the strength is reduced. It is difficult to obtain.

While the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, in the above-described embodiment, the core portion 14 fixed to the inner peripheral side of the annular outer grindstone portion 12 has a disk shape, but may have a polygonal shape.

In the above-described embodiment, a liquid epoxy resin is used in the core material adjusting step 28 in FIG. 2, but a liquid thermosetting resin such as a liquid phenol resin may be used. In the coated sand manufacturing process 50 of FIG. 7, the surface of the inorganic particles is coated with the semi-cured phenol resin, but the semi-cured epoxy resin may be coated.

In the above-described embodiment, vacuum defoaming may be performed if necessary in the core material adjusting step 28 and the pouring step 30 in FIG.

In the above-described embodiment, the aggregate refining step 26 corresponding to the step of preparing the aggregate may not always be provided, and the step of purchasing the aggregate is provided as the step of preparing the aggregate. It may be. Similarly, the coated sand manufacturing step 50 corresponding to the step of preparing the resin coated sand may not necessarily be provided, and the step of purchasing the resin coated sand may be provided as the step of preparing the resin coated sand. .

The above is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a vitrified grinding wheel manufactured by a manufacturing method according to an embodiment of the present invention.

FIG. 2 is a process diagram illustrating a main part of a method of manufacturing the vitrified grinding wheel of the embodiment of FIG.

FIG. 3 is a view for explaining a pouring step of FIG. 2;

FIG. 4 is a view showing the structure and bending strength of a vitrified grinding wheel manufactured by the manufacturing method of FIG. 2;

FIG. 5 is a view showing the breaking rotational strength of a vitrified grinding wheel manufactured by the manufacturing method of FIG. 2;

FIG. 6 is a diagram showing experimental results when various samples were manufactured by the manufacturing methods of FIGS. 2 and 7.

FIG. 7 is a process diagram illustrating a main part of another method of manufacturing the vitrified grinding wheel of the embodiment in FIG. 1;

[Explanation of symbols]

10: Vitrified grinding wheel (vitrified grinding wheel) 12: Peripheral grinding wheel portion 14: Core portion 26: Aggregate refining process (process of preparing aggregate) 28: Core portion raw material adjustment process (adjustment process) 30: Pouring process (filling process) 32) Core part curing step 50: Coated sand manufacturing step (step of preparing resin coated sand) 54: Filling step 56: Core part curing step

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Katsutoshi Takatsu 3-36 Noritakeshinmachi, Nakamura-ku, Nagoya-shi, Aichi F-term in Noritake Co., Ltd. Limited (Reference) 3C063 BC05 BD01 BG01 BG07 CC17 CC30 FF23 FF30

Claims (12)

[Claims] 1. A method for manufacturing a vitrified grinding wheel having a resin core portion exclusively for supporting the outer peripheral grindstone portion inside an outer peripheral grindstone portion having a vitrified grindstone structure in which abrasive grains are bonded by an inorganic binder. An adjusting step of adjusting the material of the core portion by mixing an aggregate and a predetermined thermosetting resin; and adjusting the material of the core portion adjusted by the adjusting step to the inside of the outer peripheral grinding stone portion. And a core hardening step of fixing the core portion inside the outer peripheral grindstone portion by hardening the material of the core portion filled in the filling process. A method for manufacturing a vitrified grinding wheel having a core part made of steel. 2. The method for producing a vitrified grinding wheel having a resin core according to claim 1, further comprising the step of preparing an aggregate having silicon oxide glass adhered to the surface of the inorganic particles. 3. The aggregate as claimed in claim 1, wherein the aggregate is made of silicon carbide or alumina having a grain size of 120 or less.
Or a method for producing a vitrified grinding wheel having a resin core part. 4. The resin core according to claim 1, wherein the adjusting step comprises mixing a liquid resin within a range of 20 to 50 parts by weight with respect to 100 parts by weight of the aggregate. A method for manufacturing a vitrified grinding wheel. 5. A grinding stone waste powder / particle forming step of generating, as the aggregate, a grinding stone waste powder obtained from a vitrified grindstone after firing, wherein the adjusting step comprises: A liquid mixed fluid is adjusted by mixing the mixed fluid with a liquid epoxy resin, and the filling step is to pour the mixed fluid into the inside of the outer peripheral grindstone portion. A method for manufacturing a vitrified grinding wheel having a core portion. 6. A method for manufacturing a vitrified grinding wheel having a resin core portion exclusively for supporting the outer peripheral grindstone portion inside an outer peripheral grindstone portion made of a vitrified grindstone structure in which abrasive grains are bound by an inorganic binder. A step of preparing a resin-coated sand having high fluidity by being coated with a predetermined resin material at least in a semi-cured state on the surface of the aggregate, and a resin-coated sand prepared by the step, A filling step of filling the inside of the outer peripheral grindstone part, and a core part curing step of fixing the core part to the inside of the outer peripheral grindstone part by curing the material of the core part filled in the filling step. A method for manufacturing a vitrified grinding wheel having a resin core. 7. The aggregate according to claim 6, wherein the aggregate is a particle made of silicon carbide or alumina having a grain size of No. 150 or less.
Of manufacturing a vitrified grinding wheel having a resin core part. 8. The method for manufacturing a vitrified grinding wheel having a resin core portion according to claim 6, wherein the aggregate is a powdery body of grinding stone waste obtained from a vitrified grinding wheel after firing. 9. The resin material is a thermosetting resin, and includes an adjusting step of mixing a thermosetting resin powder of the same type as the thermosetting resin with the resin-coated sand. A method for manufacturing a vitrified grinding wheel having such a resin core. 10. The resin-coated sand according to claim 6, wherein the surface of the aggregate is coated with a thermosetting resin in a weight ratio of 1 to 10 with respect to the aggregate 100. A method for manufacturing a vitrified grinding wheel having such a resin core. 11. The method for manufacturing a vitrified grinding wheel having a resin core according to claim 6, wherein the filling step presses the resin-coated sand when filling the resin-coated sand. 12. The filling step includes pressurizing the resin-coated sand when filling the resin-coated sand, and the core-curing step includes bonding the resin-coated sand by heating the resin-coated sand. A method for manufacturing a vitrified grinding wheel having a resin core part according to any one of claims 6 to 10.