JP3102769B2 - Resinoid 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 an improved resinoid grinding wheel containing inorganic filler particles in a resin binder.

[0002]

2. Description of the Related Art For example, a resinoid grinding wheel in which abrasive grains are bonded with a synthetic resin binder (resin bond) is used for a grinding process having a large margin such as a roughing process. Synthetic resin binder has a lower elastic modulus than vitreous binder (vitrified bond), metallic binder (metal bond), electrodeposition binder, etc. This is because the load acting on the binder can be reduced by the elastic deformation of the binder.

[0003]

In the above-mentioned resinoid grinding wheel, fine inorganic filler particles are often dispersed in a binder. That is, while the elastic deformation of the binder reduces the load acting on the abrasive grains, the excessive elastic deformation hinders the abrasive grains from cutting into the work material, and rather reduces the grinding performance. In addition, the binder that can be easily elastically deformed is only temporarily elastically deformed during dressing (sharpening and reshaping) or during grinding, even if it receives force from a dresser, chips, falling off abrasive grains, etc. It is hard to be scraped off and its surface cannot be retreated moderately. As a result, the surface of the binder is located on substantially the same plane as the tip of the abrasive grain that functions as a cutting edge, and the surface of the work material is rubbed, so that welding (that is, burning of the chip and the binder itself on the surface of the binder) occurs. As a result, the surface of the work material is roughened, and the discharge of chips is obstructed to increase the grinding resistance. In addition, the fact that the binder surface is not properly retreated also impairs the proper replacement of the abrasive grains, that is, the autogenous action of the cutting edge. Therefore, in order to obtain high grinding performance, since it is desired that the surface of the binder gradually retreats due to micro-crushing of the binder tissue, the binder is used for the purpose of substantially increasing the elastic modulus of the binder. The inorganic filler particles are dispersed therein and the abrasive grains are bound by a binder structure having an appropriate elastic modulus.

[0004] However, the binder structure in which the inorganic filler particles are dispersed not only has an increased elastic modulus, but also has a hardness as a result of the binder being firmly bonded to the inorganic filler particles and having a hardness alone. Higher than Therefore, even if the elastic modulus is increased and the elastic deformation of the binder tissue during dressing or the like is suppressed, the binder is hard to be scraped off due to the strong bonding force with the inorganic filler particles and the high hardness. However, the problem that the above-described welding occurs and the change of the abrasive grains is hindered is not sufficiently suppressed. In addition, since the surface of the binder hardly recedes as a result of the high bonding force given to the binder structure, the abrasive grains easily fall off in large units including the surrounding binder structure by welding without being replaced. In some cases, the grinding performance was rather reduced. Incidentally, as the inorganic filler particles, for example, alumina (Al
Ceramics such as ₂ O ₃ ), silica (SiO ₂ ), silicon carbide (SiC) and zirconia (ZrO ₂ ), clay minerals such as talc and mica, and fluorides are used. The constituent synthetic resin is firmly bonded to the —OH groups and the like of the inorganic filler particles.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resinoid grinding wheel having an appropriate elastic modulus and a binder structure which can be suitably retracted. It is in.

[0006]

SUMMARY OF THE INVENTION In order to achieve this object, the gist of the present invention is that abrasive grains are bound by a binder structure in which inorganic filler particles are dispersed in a synthetic resin binder. (A) The inorganic filler particles have a coating film having a lower bonding force with the synthetic resin binder than the inorganic filler particles.

[0007]

As described above, in the resinoid grinding wheel, the inorganic filler particles have a peritoneum having a lower bonding force with the synthetic resin binder than the inorganic filler particles. Therefore, at the interface between the synthetic resin binder and the inorganic filler particles, a peritoneal membrane having a low bonding force with the synthetic resin binder (that is, low adhesive strength or high releasability) is interposed, and thereby the synthetic resin is bonded. The bonding force between the binder and the inorganic filler particles is substantially reduced, and the releasability of the inorganic filler particles from the synthetic resin binder is increased. Therefore, in the resinoid grinding wheel, the elastic modulus of the binder structure is increased sufficiently by dispersing the inorganic filler particles on the inner side of the grinding surface, so that the elastic modulus of the binder is low. This inhibits the abrasive grains from digging into the work material and prevents excessive elastic deformation of the binder structure during dressing or grinding. On the other hand, on the ground surface, the exposed inorganic filler particles have a low bonding force with the synthetic resin binder and are easily dropped off. Therefore, the hardness of the binder structure near the ground surface is substantially the same as that of the synthetic resin. Since the binder tissue has a low value that is substantially the same as that when the binder tissue is composed alone, the binder tissue is easily micro-crushed gradually together with the suppression of the elastic deformation as described above and gradually. Retracted. As a result, a resinoid grinding wheel having an appropriate elastic modulus and a binder structure that can be appropriately retracted is obtained.

[0008]

In another embodiment of the present invention, preferably, the coating film is
It is composed of any of silicone resin, polyvinyl alcohol, paraffin wax (solid paraffin: solid among methane series hydrocarbons at room temperature), wax (wax: alcohol ester of fatty acid), and fluororesin. In this manner, these compounds are generally used as a release agent in molding a synthetic resin, and have a moderately low bonding strength (ie, adhesive strength) with a synthetic resin binder used in a resinoid grinding wheel. Or affinity), it is possible to sufficiently enhance the retraction of the binder structure without significantly impairing the formability of the grindstone.

Preferably, the inorganic filler particles have an average particle diameter in the range of 0.5 to 50 (μm). In order for the binder structure to be suitably micro-fractured (that is, cut off in a unit sufficiently small with respect to the average particle size of the abrasive grains), the average particle size is desirably 0.5 (μm) or more, This is because the average particle diameter is desirably 50 (μm) or less in order to maintain the bonding strength of the abrasive grains by the synthetic resin binder sufficiently high. Incidentally, the distance between abrasive grains (the size of the bond bridge) varies greatly depending on the composition ratio of the abrasive grains and the binder, but generally, the average grain size is 50%.
(μm) or more, the size of the inorganic filler particles becomes a size close to the distance between the abrasive grains, and the bonding force of the synthetic resin binder between the abrasive grains is partially lost, so that the abrasive grains easily fall off Become. More preferably, the average particle size of the inorganic filler particles is desirably about 3 to 15 (μm).

Preferably, the inorganic filler particles are contained in a ratio of 1 to 70 (% by volume) with respect to the whole binder structure. In order to sufficiently improve the elastic modulus, it is desirable that the ratio of the inorganic filler particles is 1 (volume%) or more, and the amount of the synthetic resin binder in the binder structure is reduced by excessive removal of the abrasive grains. This is because the ratio of the inorganic filler particles is desirably set to 70 (% by volume) or less in order to increase the bonding force to a sufficient level so as not to cause the generation. In order to ensure a higher elastic modulus and a higher bonding force, the ratio of the inorganic filler particles is more preferably in the range of 5 to 40 (volume%).

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the following examples, the dimensional ratios and the like of each part are not necessarily drawn accurately.

FIG. 1 is a diagram showing a cross section of a resinoid grinding wheel 10 according to one embodiment of the present invention. In the figure, a resinoid grinding wheel 10 has, for example, an outer diameter of 585 (mm) × a thickness of 75 (m).
This is a disk-type grinding wheel for double-sided surface grinding that has dimensions of about m) x 19 (mm) inside diameter and is integrally formed. The grinding surface (use surface) Use part 14 with mounting surface 12 and mounting part 1 with mounting surface 16
8. The resinoid grinding wheel 10
The whole is, for example, a particle size of about # 60 (that is, an average particle size of 200 to 30).
0 [μm]) alumina (Al ₂ O ₃ ) -based abrasive grains 20 are combined with a synthetic resin binder 22 such as a phenol resin or an epoxy resin.
A plurality of nuts 24, which are arranged evenly in the circumferential direction on several circumferences in the radial direction to be mounted on the flange of the double-sided surface grinding machine, are embedded in the mounting surface 16 with the end faces exposed. Note that a grinding liquid supply hole 26 penetrating in the thickness direction is provided at the center position.

FIG. 2A is an enlarged cross-sectional view showing the vicinity of the grinding surface 12 of the resinoid grinding wheel 10 during the processing of a work material 40 described later. A large number of inorganic filler particles 28 made of silica (SiO ₂ ), talc, mica, or the like having a particle size of about 0.5 to 50 (μm) are dispersed, and the used portion 14 includes abrasive grains 20, a synthetic resin binder 22, It is composed of inorganic filler particles 28 and numerous pores 30. In this embodiment,
A binder structure is composed of the synthetic resin binder 22 and the inorganic filler particles 28. The ratio of the abrasive grains 20, the binder structure, and the pores 30 is, for example, 50 (% by volume) and 20 (% by volume), respectively. , And 30 (% by volume). As shown in FIG. 2B, the inorganic filler particles 28 have a small bonding force with a synthetic resin binder 22 such as a silicone resin, a paraffin wax, a wax, or a fluororesin (eg, polytetrafluoroethylene). The surface of the inorganic filler particles 28 is covered with a coating film 32 having a thickness of about 1/5 or less of the particle diameter of the inorganic filler particles 28 themselves. The binding strength between the synthetic resin binder 22 and the abrasive grains 20 and the coating film 32 is determined, for example, by preparing a test piece in which only the treated inorganic filler particles 28 and the binder are mixed, and measuring the bending strength of the test piece. And abrasion test, and electron microscopic observation of the fractured surface.

The above-mentioned resinoid grinding wheel 10 is manufactured, for example, as follows. That is, first, the organic compound constituting the coating film 32 is dissolved in a solvent such as alcohol so as to have a ratio of, for example, about 1 (%) with respect to the inorganic filler particles 28, To mix the solution with the inorganic filler particles 28. At this time, the amount of the solvent is such that the inorganic filler particles 28 are slightly wet. As a result, the surface of the inorganic filler particles 28 is covered with the organic compound dissolved in the solvent. Next, the above-mentioned synthetic resin binder 20 in a powder state, for example, is mixed with the inorganic filler particles 28 in a mixer.
And the mixture is mixed so that the ratio is about 99 to 30 (% by volume), and then the abrasive grains 20 are charged into a mixer to further mix. The amount of the abrasive particles 20 to be introduced is a ratio when the resinoid grinding wheel 10 is mixed. For example, the abrasive particles 20 are about 70 (volume%), and the synthetic resin binder 22 constituting the binder structure is used.
And the inorganic filler particles 28 are determined to be about 30 (% by volume). The mixture prepared as described above is subjected to powder pressure molding using a mold having dimensions of the above-mentioned grindstone in consideration of curing shrinkage, and aging at, for example, an aging temperature of about 180 (° C.). Is obtained.

FIG. 3 is a view showing a use state of the above-mentioned resinoid grinding wheel 10 in a double-sided surface grinding machine. In the figure, the double-sided surface grinder is provided with a pair of flanges 36, 36 provided opposite to each other and driven to rotate by rotation shafts 34, 34, respectively. Are mounted on the opposed surfaces of the flanges 36, 36 by a plurality of bolts 38. Between the pair of resinoid grinding wheels 10, 10, there is provided a guide 42 for continuously feeding a workpiece 40 such as an outer ring of a bearing, for example, in one direction from the back surface to the front surface of the paper. Resinoid grinding wheel 10, 10
Are located apart from each other by a distance corresponding to the processing dimensions of the work material. In this double-sided surface grinding machine, the work material 40 is supplied between the pair of resinoid grinding wheels 10, 10 while the pair of resinoid grinding wheels 10, 10 are rotated in the directions indicated by arrows in the drawing. Thus, the plurality of workpieces 40 are sequentially processed to a predetermined size.

In the double-sided surface grinder shown in FIG. 3, the width dimension (length in the axial direction) of the bearing outer ring is sintered by a resinoid grinding wheel 10 having various binder structures shown in Table 1 below. The results of the input grinding are shown in Table 2 below together with comparative examples that are outside the scope of the present invention. In Table 1, the numerical values in parentheses in the column of “inorganic filler particles” represent the average particle size of the inorganic filler particles 28. The “capacity part” represents a volume ratio (capacity [%]) of each of the resin binder 22 and the inorganic filler particles 28 to the total capacity of the resinoid grinding wheel 10. Represents the volume ratio of the inorganic filler particles 28 to the volume ratio. In Table 2, "power consumption"
Is the power value applied at the time of machining, and the lower the value, the better the sharpness of the grindstone. The “number of processes” is the number of work pieces 40 that can be processed per one set of grindstones. The processing conditions are as follows. [Processing conditions] ・ Wheel peripheral speed: 1800 (m / min) ・ Work material: SUJ-2 (hardened material, HRC hardness 60-7)
0)-Work material allowance: 0.3 (mm)

[0017]

[Table 1]

[0018]

[Table 2]

As is apparent from Table 2, according to the resinoid grinding wheel 10 of this embodiment, a large number of workpieces 40 are ground with relatively low power consumption without causing "burn" on the surface 46 thereof. It was possible. This is because, as shown in FIG. 2 (a), the binder tissue surface 44 is sufficiently retracted from the ground surface 12 (i.e., the tip surface of the abrasive grain 20 functioning as a cutting edge) during the grinding process. And abrasive grains 20
Results in a state in which it is appropriately protruded from the ground surface 12,
This is because the surface 44 of the binder is hardly brought into contact with the surface 46 of the work material, so that the surface 44 is less likely to be welded and the high grinding performance is maintained. In addition, in the grinding wheel, since it is desired that many grinding can be performed with low electric power without burning, it is evaluated that the larger the value of “number of processing / power” in Table 2 above, the higher the grinding performance. it can. For example, if “the number of processed / power” is 100 or more, it can be said that the grinding performance is sufficiently high. However, according to the present embodiment, the value is as high as 140 or more. It can be said that it has extremely high grinding performance as compared with a grindstone.

On the other hand, for example, in the resinoid grinding wheel of Comparative Example 21 in which the inorganic filler particles 28 are not contained in the binder structure, the power load is extremely large, and the burnt surface Occurred and processing was impossible. That is, as shown in FIG. 4, in a grindstone that does not include the inorganic filler particles 28, the synthetic resin binder 22
Is excessively elastically deformed, so that the abrasive grains 20 are prevented from biting into the work material 40. In addition, during dressing or during grinding, the abrasive grains 20 receive force from a dresser, chips, falling off abrasive grains, and the like. Even if the binder tissue is temporarily elastically deformed, it is hard to be scraped off, and the surface 44 thereof cannot be appropriately retreated. Therefore, the surface 48 of the synthetic resin binder 22 is positioned substantially on the same plane as the tip surface of the abrasive grains 20 and rubs the work material surface 46, so that welding 48 occurs, and the work material surface 46
And increase the grinding resistance by inhibiting the discharge of chips. For this reason, as shown in Table 2 above, the power consumption increased and machining was impossible.

FIG. 5 is a view showing the vicinity of the grinding surface 12 of the resinoid grinding wheel of Comparative Examples 22 to 25 in which the inorganic filler particles 50 without the coating film 32 are contained in the binder structure. However, also in this case, as shown in the drawing, since the welding 48 is likely to occur, the power consumption is increased as compared with the first to thirteenth examples, and the work material 22 which can be machined by one set of grindstones is used. The quantity decreases. Comparative Examples 22 to 25
Since the elastic modulus of the binder structure is increased by the inclusion of the inorganic filler particles 50 in the synthetic resin binder 22, the bonding during grinding or the like as shown in FIG. 4 (Comparative Example 21) is performed. Elastic deformation of the agent tissue is unlikely to occur,
Since the synthetic resin binder 22 is firmly bonded to the inorganic filler particles 50, the hardness is also increased as compared with the case of the binder alone. Therefore, despite the fact that the elastic deformation is suppressed, the binder structure is hard to be scraped off, so that the surface 44 does not suitably recede, so that the welding 48 occurs and the replacement of the abrasive grains 20 is inhibited, As shown in Table 2, high grinding performance cannot be obtained. In addition, since the surface 44 hardly recedes as a result of the high bonding force applied to the binder tissue, the abrasive grains 2 shown by the broken line
As in the case of Oa, there is also a problem that the abrasive grains 20 easily fall off in large units including the surrounding binder structure without being replaced.

In Comparative Example 24, since mica used as the inorganic filler particles 50 does not have as high a bonding force with the synthetic resin binder 22 as silica, "burn" occurs under the above grinding conditions. However, since the inorganic filler particles 50 are not easily separated from the binder structure, the power consumption is higher and the number of processes is smaller than in this embodiment. Therefore, in the resinoid grinding wheel of Comparative Example 24 as well, it is estimated that "burn" is likely to occur under more severe grinding conditions than in the above case.

On the other hand, in Comparative Examples 26 to 29,
Inorganic filler particles 28 having a coating film 32 as in the case of 20
Is used, the degree of scorching is considerably better as compared with 21 to 25. However, in Comparative Example 26, the particle size of the inorganic filler particles 28 was 0.3 (μm).
Since it is too small, the retreating property of the binder 22 from the ground surface 12 is poor, the power consumption is high, and the work material 40 is not completely burnt but slightly burnt. In Comparative Example 27, since the particle size of the inorganic filler particles 28 is too large, about 55 (μm), the bonding force of the synthetic resin binder 22 between the abrasive grains 20 due to the inorganic filler particles 28 is partially lost. As a result, the abrasive grains 20 are apt to fall off excessively, and although the power consumption is extremely low, the retreat speed of the grinding surface 12 is extremely high, and the number of machining is reduced. Therefore,
The particle size of the inorganic filler particles 28 is preferably in the range of about 0.5 to 50 (μm) as shown in Examples 1 to 20. In Examples 1 to 20, Example 12,
13, the particle size is more preferably 3 (μm) or more, and as is clear from the comparison of Examples 14 to 16, the particle size is more preferably 15 (μm) or less. preferable. That is, the particle size of the inorganic filler particles 28 is 3
The range of about 15 (μm) is most preferable.

In Comparative Example 28, the volume ratio of the inorganic filler particles 28 in the binder structure was 0.5 (% by volume).
Since the amount was extremely small, the effect of adding the inorganic filler particles 28 could hardly be obtained, the power consumption increased, and "burning" occurred, making it almost impossible to process. Further, in Comparative Example 29, since the volume ratio of the inorganic filler particles 28 in the binder structure was excessively large at about 74 (% by volume), the abrasive particles 20 were more likely to fall off than in Comparative Example 27. Substantially no grinding was possible. Therefore, the volume ratio of the inorganic filler particles 28 in the binder structure is preferably in the range of 1 to 70 (% by volume).
In Examples 1 to 20, it is more preferable that the amount of the inorganic filler particles 28 is 5% (by volume) or more, as is clear from the comparison between Examples 1 and 2.
As is clear from the comparison of No. 8, it is more preferable that the content be 40 (% by volume) or less. That is, the volume ratio of the inorganic filler particles 28 is most preferably in the range of about 5 to 40 (% by volume).

In short, in this embodiment, in the resinoid grinding wheel 10, the inorganic filler particles 28 are provided so as to cover the respective surfaces, and the bonding force with the synthetic resin binder 22 is higher than that of the inorganic filler particles 28. Low peritoneum 32
Is configured. Therefore, at the interface between the synthetic resin binder 22 and the inorganic filler particles 28, the synthetic resin binder 2
2, the bonding force between the synthetic resin binder 22 and the inorganic filler particles 28 is substantially reduced, and the synthetic resin binder of the inorganic filler particles 28 is reduced. The releasability from 22 is improved. Therefore, in the resinoid grinding wheel 10, the elastic modulus of the binder structure is increased sufficiently inside the grinding surface 12 by dispersing the inorganic filler particles 28. Of the abrasive grains 20 from cutting into the work material 40 due to the low elastic modulus of
Excessive elastic deformation of the binder structure during dressing or grinding is suppressed. On the other hand, on the ground surface 12, the exposed inorganic filler particles 28 have a low bonding force with the synthetic resin binder 22 and are easily dropped off, so that the hardness of the binder structure near the ground surface 12 is substantially reduced. As a result, the binder tissue is easily reduced to a very small value in combination with the fact that the elastic deformation is suppressed as described above since the binder tissue has a low value substantially similar to the case where the synthetic resin binder 22 is used alone. It is crushed and gradually retreated. As a result, a resinoid grinding wheel 10 having an appropriate elastic modulus and a binder structure that can be appropriately retracted is obtained.

Moreover, in this embodiment, the coating film 32
Is composed of any of silicone resin, paraffin wax, wax, and fluororesin. Therefore, these organic compounds are generally used as a release agent when molding the synthetic resin constituting the synthetic resin binder 22, and have a moderately low binding force (that is, a high binding force) with the synthetic resin binder 22. (Removability or low affinity), the retraction of the binder structure can be sufficiently improved without significantly impairing the formability of the resinoid grinding wheel 10.

In this embodiment, the average particle diameter of the inorganic filler particles 28 is in the range of 0.5 to 50 (μm).
Therefore, since the particle size of the inorganic filler particles 28 is sufficiently smaller than the size of the bond bridge, the bonding force of the abrasive particles 20 by the synthetic resin binder 22 is maintained sufficiently high, and the binder structure is reduced. For example, the particles are suitably finely crushed in units sufficiently smaller than the particle diameter of the abrasive grains 20 of, for example, about 200 to 300 (μm), and higher grinding performance can be obtained. In particular,
When the average particle size of the inorganic filler particles 28 is in the range of about 3 to 15 (μm), higher grinding performance can be obtained.

Further, in the present embodiment, the inorganic filler particles 28 are 1 to 70 (% by volume) based on the whole binder structure.
Are included in the ratio of the range. Therefore, while the elastic modulus is sufficiently improved, the amount of the synthetic resin binder 22 in the binder structure is set to be large enough to obtain a sufficient bonding force so that the abrasive particles 20 do not fall off excessively. Therefore, higher grinding performance can be obtained. In particular, when the proportion of the inorganic filler particles is in the range of 5 to 40 (% by volume), a higher bonding force can be secured while securing a higher elastic modulus.

While one embodiment of the present invention has been described in detail with reference to the drawings, the present invention may be embodied in still another embodiment.

For example, in the embodiment, the case where the present invention is applied to the disk-type resinoid grinding wheel 10 for a double-sided surface grinder has been described. The present invention is similarly applied to various grinding wheels such as a ring-type surface grinding wheel, a cup-type grinding wheel, a cylindrical grinding wheel, a centerless grinding wheel, and an inner surface grinding wheel.

Further, in the embodiment, the resinoid grinding wheel 10 using the abrasive grains 20 made of alumina having a grain size of about # 60 has been described, but the silicon carbide (SiC) abrasive grains,
Resinoids using other general abrasives such as zirconia-alumina (ZrO ₂ -Al ₂ O ₃ ) abrasives, superabrasives such as cubic boron nitride (CBN) abrasives and diamond abrasives, or a mixture thereof The present invention is similarly applied to a grinding wheel, and the particle size of the abrasive grains 20 is appropriately changed.

Further, in the embodiment, the entire resinoid grinding wheel 10 is composed of a grindstone structure in which the abrasive grains 20 are bound by a synthetic resin binder 22. The present invention can be similarly applied to a segment-type whetstone having a segment whetstone adhered thereto.

In the embodiment, the inorganic filler particles 28 are made of silica, talc, mica, etc. of about 0.5 to 50 (μm), and the coating film 32 is made of silicone resin, paraffin wax, wax, fluorine resin or the like. However, the inorganic filler particles 28 include alumina (Al ₂ O ₃ ), silicon carbide (SiC), and zirconia (ZrO ₂ ).
Various inorganic materials having a sufficiently higher elastic modulus than the synthetic resin binder 22 can be used, such as ceramics, other clay minerals, fluorides, and the like. Other organic compounds such as polyvinyl alcohol may be used as long as the compound has a smaller bonding force with the synthetic resin binder 22 than the compound.

The coating film 32 is formed of the inorganic filler particles 28.
When a film is formed on the surface of the organic compound, the organic compound dissolved in the solvent is mixed with the inorganic filler particles 28. However, when a liquid organic compound is used, the step of dissolving in the solvent is unnecessary, and the film formation is not performed. As a method, a dispersion coating method often performed with a fluororesin or the like may be adopted.

In the embodiment, since the resinoid grinding wheel 10 is manufactured using the powdery synthetic resin binder 22, the resinoid grinding wheel 10 is formed by powder pressure molding. The present invention is similarly applied to a resinoid grinding wheel 10 manufactured by casting into a predetermined mold using the synthetic resin binder 22 of the above.

In the embodiment, the resinoid grinding wheel 10 is composed of 50 (volume%) abrasive grains 20, 20 (volume%) binder structure, and 30 (volume%) pores 30. However, these ratios are appropriately changed depending on the grinding application. For example, the present invention can be applied to a nonporous resinoid grinding wheel.

Although not specifically exemplified, the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a view showing a cross-sectional structure of a resinoid grinding wheel according to one embodiment of the present invention.

2 (a) is an enlarged view showing a cross section near a grinding surface of the resinoid grinding wheel of FIG. 1, and FIG. 2 (b) is an enlarged view showing inorganic filler particles in (a). is there.

FIG. 3 is a schematic diagram illustrating a use state of the resinoid grinding wheel of FIG. 1;

FIG. 4 is a view corresponding to FIG. 2 (a) of a conventional resinoid grinding wheel in which no inorganic filler particles are used.

FIG. 5 is a view corresponding to FIG. 2 (a) in a conventional resinoid grinding wheel using inorganic filler particles.

[Explanation of symbols]

 10: Resinoid grinding wheel 20: Abrasive particles 22: Synthetic resin binder 28: Inorganic filler particles 32: Coating film

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-277956 (JP, A) JP-A-5-337833 (JP, A) JP-A-54-106990 (JP, A) JP-A-63- 34072 (JP, A) JP-A-8-90423 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B24D 3/02 B24D 3/28

Claims (4)

(57) [Claims] 1. A resinoid grinding wheel in which abrasive grains are bonded by a binder structure in which inorganic filler particles are dispersed in a synthetic resin binder, wherein the inorganic filler particles comprise Characterized in that it has a coating film whose bonding force is lower than that of the inorganic filler particles. 2. The resinoid grinding wheel according to claim 1, wherein said coating film is made of any one of silicone resin, polyvinyl alcohol, paraffin wax, wax, and fluororesin. 3. The inorganic filler particles have an average particle diameter of 0.5.
The resinoid grinding wheel according to claim 1, which is in the range of 5 to 50 (µm). 4. The resinoid grinding wheel according to claim 1, wherein the inorganic filler particles are contained in a ratio of 1 to 70 (% by volume) with respect to the entire binder structure.