JP2003062756A - Resinoid grinding wheel using hydrogenerated bisphenol a type epoxy resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resinoid grinding wheel in which synthetic resin bond has appropriated retaining power with respect to an abrasive grain and excellent ground material surface grade is continuously obtained by making a cutting edge formed spontaneously, even though a fine abrasive grain having grain size of #800 or more is used in a resinoid grinding wheel. SOLUTION: Hydrogenerated bisphenol A used as a principal raw material of a synthetic resin bond 18 satisfies conditions that viscosity at mixture with curing agent is 1 Pa.s or less and that the glass transition temperature of single unit after curing is 100 deg.C or higher, wherein the hydrogenerated bisphenol A whose flexural modulus of the unit after curing becomes 2 GPa or less can be easily obtained. Therefore, even though a abrasive grain 16 having grain size of #800 or more is used in a resinoid grinding wheel 10, the resinoid grinding wheel 10 in which the synthetic resin bond 18 has appropriate retaining force with respect to the abrasive grain 16 and an excellent surface grade of a ground material 20 is continuously obtained by making a cutting edge formed spontaneously 26 formed spontaneously, can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resinoid grinding in the technical field of a grinding wheel, in which a hydrogenated epoxy resin is used as a binder, and abrasive grains having a particle size of # 800 or more are mutually bonded. Regarding the whetstone.

[0002]

2. Description of the Related Art For example, a resinoid grinding wheel in which abrasive grains are bonded by a synthetic resin binder is generally used for a grinding process with a large machining allowance such as a roughing process. Resinoid grinding wheels are preferably used for such grinding because synthetic resin binders that bind the abrasive grains are used for vitreous bond (vitrified bond), metallic bond (metal bond), electrodeposition bond, etc. This is because the elastic modulus is relatively low, so that the load acting on the abrasive grains from the work material during the grinding process can be relaxed by the elastic deformation of the binder. In particular, resinoid grinding wheels that use epoxy resin as a binder have a lower elastic modulus than those that use phenol resin as a binder, and are one of the longest of the above operations that take advantage of their characteristics. It is widely used for processing thin pipes and thin pipes. Among resinoid grinding wheels using such an epoxy resin as a binder, the above properties can be most remarkably utilized by a manufacturing method in which a liquid epoxy resin and abrasive grains are mixed and then cast into a mold. It is manufactured, and the low elastic modulus which is the characteristic of the epoxy resin, and the physically strong bond due to the wetting of the abrasive grains and the binder obtained by this casting manufacturing method work together to give the resinoid grindstone. It is considered to give excellent grinding performance.

[0003]

However, in order to improve the quality of the work surface of the work material, in the resinoid grinding wheel using epoxy resin as a binder, which uses fine abrasive particles having a grain size of # 800 or more, the grinding wheel is used. The desired surface quality of the work material can be continuously obtained due to the unevenness of the work surface of the work material caused by clogging and welding of cutting chips on the surface, and the fact that it may have a spiral mark or scratches. However, there was a problem that dressing was frequently required.

The present invention has been made to solve the above problems, and its object is to obtain a grain size of # 8.
Even with resinoid grinding wheels that use fine abrasive grains of 00 or more, the synthetic resin binder has an appropriate holding power for the abrasive grains, and the cutting edge is self-generated to maintain good surface quality of the work material. It is to provide a resinoid grinding wheel that can be obtained as a result.

[0005]

Means for Solving the Problems The present inventor has continued to study the above problems, and relates to a resinoid grindstone using an epoxy resin as a binder, which uses fine abrasive grains having a grain size of # 800 or more,
The above-mentioned problem occurs because the bond between the abrasive grains and the epoxy resin as the binder is too strong for the fine abrasive grains having a grain size of # 800, which prevents the self-generation of the cutting edge. Came to. That is, the work in which a resinoid grinding wheel using fine abrasive grains is used generally has a smaller load during grinding than the case of coarse grains, and the number of abrasive grains involved in grinding on the work surface of the work material. In the case of fine abrasive grains, it will inevitably increase, and as a result, the load on one abrasive grain will be small, so the binding force for holding the abrasive grains by the binder is the same for fine abrasive grains and coarse grains. Even in this case, it was thought that since the force for removing the abrasive grains was relatively small in the case of fine abrasive grains, proper self-generation of the cutting edge did not occur.

By the way, it is generally considered that the binding force of the epoxy resin is dominated by the binding force of the physical caulking. To reduce the binding force, the elastic modulus of the epoxy resin alone is lowered. There is a need. In order to reduce the elastic modulus of the epoxy resin whose main raw material is bisphenol A, which is generally used as a synthetic resin binder for resinoid grinding wheels, a reactive diluent must be added at the manufacturing stage. The addition of a hydrophilic diluent reduces not only the elastic modulus of the synthetic resin binder but also the heat resistance, so the grinding performance of the resinoid grinding wheel tends to vary due to the temperature change of the grinding fluid used during grinding. In addition to new problems related to performance, in the manufacture of resinoid grinding wheels, the viscosity of the resin when mixed with the curing agent increases, so it is not mixed well with the abrasive grains. It is conceivable that a manufacturing problem such as abnormal acceleration of the curing of the resin will occur.
The resin mixture viscosity (viscosity when a resin is mixed with a hardening agent) for obtaining a sufficient mixed state with fine abrasive grains having a particle size of # 800 or more is generally 1 Pa · s or less, and variations in this condition and grinding performance In order to control the glass transition temperature of the cured simple substance to be 100 ° C. or higher, the material such as bisphenol A has a modulus of the cured simple substance of at least 3 GPa.

The present invention has been made in view of the above circumstances, and its gist is that abrasive grains having a grain size of # 800 or more are bonded to each other by a synthetic resin binder. A resinoid grinding wheel, wherein the synthetic resin binder uses a main agent containing hydrogenated bisphenol A as a main raw material.

[0008]

As described above, the hydrogenated bisphenol A used as the main raw material of the synthetic resin binder has a viscosity of 1 Pa · s or less when mixed with the curing agent and a glass transition temperature of the simple substance after curing. Is a resinoid grinding wheel using fine abrasive grains with a grain size of # 800 or more, since a flexural modulus of the cured single substance of 2 GPa or less can be easily obtained. Also, it is possible to provide a resinoid grinding wheel in which the synthetic resin binder has an appropriate holding force for the abrasive grains and the cutting edge is self-generated to continuously obtain a good work material surface quality.

[0009]

Other Embodiments Here, it is preferable that the synthetic resin binder has a viscosity of 1 Pa · when the main agent and the curing agent are mixed.
s or less. By doing so, in the manufacture of the resinoid grinding wheel 10, the viscosity when mixing the main raw material of the synthetic resin binder and the curing agent is sufficiently low, so that mixing with the abrasive grains is favorably performed, and at the time of mixing There is no problem in production such as abnormally accelerating the curing of the epoxy resin by the heat of stirring.

Preferably, the synthetic resin binder is
The glass transition temperature of the simple substance after curing is 100 ° C. or higher. In this way, problems relating to the performance of the grindstone, such as variation in the grinding performance of the resinoid grinding grindstone due to temperature changes of the grinding fluid used during grinding, do not occur.

Also preferably, the synthetic resin binder is
The flexural modulus of the single body after curing is 2 GPa or less. By doing so, even in the resinoid grinding wheel using fine abrasive grains having a grain size of # 800 or more, the synthetic resin binder has an appropriate holding force for the abrasive grains and allows the cutting edge to grow naturally. It is possible to provide a resinoid grinding wheel that can continuously obtain good work material surface quality.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing the shape of a resinoid grinding wheel 10 which is an embodiment of the present invention. In the figure, the resinoid grinding wheel 10 has an outer diameter of 500, for example.
(Mmφ) x thickness 150 (mm) x inner diameter 200 (mm
(φ) is a cylindrical grinding type disk-shaped grindstone that is integrally formed as a whole and has a mounting hole 1 provided at the center.
2 is attached to a spindle of a grinding machine (not shown),
While supplying the grinding liquid between the outer peripheral grinding surface 14 and the work material,
The work piece held by a holding device (not shown) is ground to the outer peripheral surface 1
In the state of being pressed against 4, it is rotated around its axis and used. As a result, the work surface of the work material is the outer peripheral grinding surface 14
Is ground into a desired shape.

FIG. 2 is an enlarged view showing the structure of the resinoid grinding wheel 10 described above. In this figure, a resinoid grinding wheel 10 has a general abrasive grain 16 such as SiC or fused alumina, or a superabrasive grain 16 such as CBN or diamond.
Are bonded to each other by a resin bond, that is, a synthetic resin binder 18 to have a large number of pores 22. In the resinoid grinding wheel 10 configured as described above, the outer peripheral grinding surface 14 is brought into sliding contact with the work surface 24 of the work material 20 as described above, so that the cutting edge 26 of the abrasive grain 16 is cut. The surface 24 to be cut is ground. When a part of the abrasive grains 16 is crushed by the grinding, the next cutting edge 26 is regenerated and the grinding performance is continued. The weight ratio of the synthetic resin binder 18 to the abrasive grains 16 or the whole is determined so that the abrasive grains 16 are exclusively and sufficiently bonded, and when the crushed abrasive grains 16 become smaller, the synthetic resin binder 18 becomes smaller. Since the holding power of 18 is lowered, it is removed together with the crushed abrasive grains 16 so that the next abrasive grain 16 is involved in the grinding. At this time, as the number of abrasive grains 16 increases, that is, as the grain size decreases, the number of cutting edges 26 involved in grinding decreases and at the same time the number of cutting edges increases. The smooth surface quality of the processed product can be obtained.

The resinoid grinding wheel 10 of this embodiment is manufactured, for example, as follows. First, as a synthetic resin binder 18, 26 parts by volume of a hydrogen bisphenol A, for example, hexahydrobisphenol A diglycidyl ether as a main raw material, and 26 parts by volume of a curing agent, for example, an amine curing agent, were mixed in a mixer or the like. It is thrown in and stirred quickly. Subsequently, the synthetic resin binder raw material mixed in this way has abrasive grains 16 of, for example, a grain size of # 1000.
Fused alumina (Al ₂ O ₃ ) abrasive grains are 20 parts by volume,
An organic balloon having an average particle size of about 100 μm and 15 parts by volume are further charged and stirred for a predetermined time, for example, about 10 minutes. The organic balloon is introduced for the purpose of forming pores 22.

The main raw materials of the synthetic resin binder 18 of this embodiment are as follows: the glass transition temperature of the cured simple substance is 115 ° C., the viscosity when mixed with the curing agent is 0.6 Pa · s, and the cured simple substance is Hydrogenated bisphenol A with a flexural modulus of 1.8 GPa
Is used. Here, hydrogenated bisphenol A is a compound in which hydrogen has been added to the double bond of bisphenol A, and some double bonds may remain. As described above, hydrogenated bisphenol A is cured after curing under conditions that the resin mixture viscosity (viscosity when the resin is mixed with the curing agent) is 1 Pa · s or less and the glass transition temperature of the cured simple substance is 100 ° C. or higher. Since it has the characteristic that the bending elastic modulus of the simple substance can be suppressed to 2 GPa or less as described above, it is used as the main raw material of the synthetic resin binder 18 to obtain fine abrasive grains having a grain size of # 800 or more. Even in the resinoid grinding wheel 10 using 12, the synthetic resin binder 18 has an appropriate holding force for the abrasive grains 12, and the cutting edge 26 is suitable as described above. It is possible to provide the resinoid grinding wheel 10 that can be naturally grown. That is, if the glass transition temperature of the synthetic resin binder 18 after curing is 100 ° C. or higher, the grinding performance of the resinoid grinding wheel 10 does not vary due to the temperature change of the grinding fluid during grinding, and the above grinding stone raw material is used. In the mixing step, the viscosity of the grindstone raw material to be mixed is 1 Pa · s
If it is below, the problem that the epoxy particles are sufficiently mixed with the abrasive grains 12 and the stirring heat is generated and the curing of the epoxy resin is abnormally accelerated does not occur.

Next, 30 parts by volume of a foamed polystyrene resin having an average particle size of about 1 mm (expansion ratio: 10 times) was added to the mixture mixed in the above steps, and then further stirred for a predetermined time, for example, about 5 minutes. It This expanded polystyrene resin functions to form large pores (not shown) having a diameter larger than the pores 22 and functioning as a chip pocket in the grindstone structure. The grindstone raw material thus adjusted is subsequently cast into a predetermined mold, and the
The resinoid grinding wheel 10 is formed by being left for about 4 hours to be hardened to some extent, then demolded, and then subjected to a main hardening treatment of holding at about 160 ° C. for 3 hours.

The grinding test conducted by the present inventor will be described below. First, an example sample which is one example of the present invention was prepared by the above steps, and subsequently, the same raw materials and steps as the above example samples were used except that bisphenol A was used as the main raw material of the synthetic resin binder 18. A comparative sample was prepared. The raw material of the comparative example sample, bisphenol A, has a bending elastic modulus of 2.9 GPa after curing, a viscosity of 0.5 Pa · s when mixed with a curing agent, and a glass transition temperature of 105 ° C. after curing. I used the following. The shape of each of the example sample and the comparative example sample thus formed is 455
(Mmφ) x thickness 150 (mm) x inner diameter 228.6 (m
mφ). A grinding test for verifying the effect of the present invention was conducted under the following test conditions using the sample of this example and the sample of comparative example.

[Test conditions] Grinding machine: Centerless grinding machine Grinding wheel peripheral speed: 2000 m / min Work material: S45C raw material Work material size: φ15 × L100 Grinding method: Through feed grinding Work material feeding speed: 5 m / min Adjusting whetstone: Rubber whetstone (outer diameter 255mmφ, thickness 150
mm, inner diameter 127 mm)

3A and 3B are views showing the relative positional relationship between the resinoid grinding wheel 10 and the work material 20 in this experiment. FIG. 3A is a plan view and FIG. 3B is a front view. In the grinding test, as shown in FIG. 3A, between the resinoid grinding wheel 10 of the example sample or the comparative example sample and the adjusting grindstone 30 for correcting when these samples are worn by grinding. , A cylindrical work material 20 having an outer diameter of 15 (mmφ) and a length of 100 (mm) is continuously fed in the direction indicated by an arrow in FIG. 3A, that is, in the direction of the rotation axis of the resinoid grinding wheel 10. Grinded. Here, the adjusting grindstone 30 is shown in FIG.
As shown in, the shaft center was used with the resinoid grinding wheel 10 slightly tilted from the shaft center direction. When the machining allowance provided on the work material 20 is started from the setting of 10 μmφ and the machining allowance is 5 μmφ, the work material 20 in the direction indicated by the arrow in FIG.
The adjustment grindstone 30 is moved forward by 5 μm in the direction of the normal line of the contact point, and the correction of returning the stock removal of the work material 20 to 10 μmφ is repeated, and the power consumption value (kW) of the grinder spindle for the number of work pieces 20 The change and the surface quality (μRz) of the work surface 24 of the work material 20 were evaluated.

FIG. 4 shows the work material 2 obtained as a result of the grinding test.
It is a graph which shows the transition of the power consumption value of the grinder spindle with respect to the number of machining of 0. According to this graph, in the grinding with the resinoid grinding wheel 10 as the example sample, the initial power consumption value is about 30% lower than that with the resinoid grinding wheel 10 as the comparative sample, and The power consumption value tends to gradually decrease as the number of processed pieces increases. From this, it is understood that the grindstones of the example samples are appropriately worn by grinding. Further, in the graph of the example sample, the power consumption value increases near 180 and around 450, but this is because the machining allowance of the work material 20 is 5 μmφ, so that the adjustment grindstone 30 of the work material 20 is 5 μm in the direction
This is because the correction is performed such that the work material 20 is moved forward and the stock removal of the work material 20 is returned to 10 μmφ. With this correction, the power consumption value once rises to a value close to the initial value, but the power consumption value gradually decreases as the number of machining increases. On the other hand, in the resinoid grinding wheel 10 as the comparative example sample, the power consumption value tended to decrease as the number of processed materials 20 increased up to about 130, but if this number was exceeded, The power consumption value gradually increased, and unevenness in gloss occurred on the work surface 24 of the work material 20 at the stage when the 440th work was finished, so the grinding was stopped. Further, in the comparative sample, since the work material removal amount did not decrease even if the grinding was continued, no correction was performed.

Similarly, the work material 2 obtained as a result of the grinding test
The state (ten-point average roughness) of the work surface 24 of the work material 20 with respect to the number of machining of 0 is shown below.

Number of pieces to be processed (pieces) 1 150 300 440 450 600 Working surface of sample (μRz) 0.32 0.30 0.29 ― 0.29 0.29 Working surface of sample (μRz) 0.35 0.33 0.32 0.30 ― ― [Remarks] Comparative sample In the grinding test according to the above, since the unevenness of gloss occurred on the work surface of the work material at the stage when the 440th work was finished, the grinding was stopped.

According to this result, in the grinding with the resinoid grinding wheel 10 which is the sample of the embodiment, 6
The desired surface quality was obtained without problems such as gloss unevenness, spiral marks, and scratches on the work surfaces 24 of all of the 00 work materials 20, whereas grinding with the resinoid grinding wheel 10 as a comparative example sample was performed. As described above, the unevenness of gloss was generated on the work surface 24 of the work material 20 at the 440th line and the state was observed up to the 445th line, but this unevenness of gloss was not cured.

From the above test results, the synthetic resin binder 18
By using hydrogenated bisphenol A as the main raw material of
Even in the resinoid grindstone 10 using the fine abrasive grains 16 having a grain size of # 800 or more, the synthetic resin binder 18 has an appropriate holding force with respect to the abrasive grains 16, and the cutting edge 26 is naturally grown to be excellent. It was confirmed that the resinoid grinding wheel 10 capable of continuously obtaining the surface quality of the work material 20 can be provided.

As described above, according to this embodiment, the hydrogenated bisphenol A used as the main raw material of the synthetic resin binder 18 has a viscosity of 1 Pa · s or less when mixed with a curing agent and a simple substance after curing. Has a glass transition temperature of 100 ° C or higher, and has a flexural modulus of 2GP after curing.
Particles of # 800 or less can be easily obtained, so the particle size is # 800.
Even in the resinoid grinding wheel 10 using the fine abrasive grains 16 as described above, the synthetic resin binder 18 has an appropriate holding force with respect to the abrasive grains 16 and causes the cutting edges 26 to grow to produce the work material 20. It is possible to provide the resinoid grinding wheel 10 capable of continuously obtaining good surface quality of

Further, according to this embodiment, the synthetic resin binder has a viscosity of 1 Pa · s when mixed with the main agent and the curing agent.
In the production of the resinoid grinding wheel 10, the viscosity of the main raw material of the synthetic resin binder 18 and the curing agent is sufficiently low in the production of the resinoid grinding wheel 10, so that the mixing with the abrasive grains 16 is preferably performed. That is, there is no problem in production such as abnormally accelerating curing of the epoxy resin by stirring heat during mixing.

Further, according to this embodiment, since the synthetic resin binder has a glass transition temperature of 100 ° C. or higher after being hardened, resinoid grinding is performed depending on the temperature change of the grinding liquid used during grinding. There is no problem with the performance of the grindstone such that the grinding performance of the grindstone 10 is likely to vary.

Further, according to the present embodiment, since the synthetic resin binder has a flexural modulus of elasticity of 2 GPa or less after curing, a fine abrasive grain 16 having a grain size of # 800 or more is used. Even with the resinoid grinding wheel 10 that was previously used, the synthetic resin binder 18 has an appropriate holding force with respect to the abrasive grains 16, and the cutting edge 26 is self-grown to maintain a good surface quality of the work material 20. The obtained resinoid grinding wheel 10 can be provided.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in still another mode.

For example, although the resinoid grinding wheel 10 which is a cylindrical grinding disk-shaped grinding wheel has been described in the above embodiment, the present invention is not limited to this, and the synthetic resin binder 1
It is widely used for resinoid grinding wheels composed of abrasive grains 16 having a grain size of # 800 or more bonded to each other by 8, such as a surface-grinding disc-shaped grindstone, a cup-shaped grindstone, and an inner grinding wheel. It is suitably used for various resinoid grinding wheels such as.

In the above embodiment, the grain size is # 100.
About 0 alumina (Al ₂ O ₃ ) abrasive grains were used, but other general abrasive grains such as silicon carbide (SiC) abrasive grains and zirconia-alumina (ZrO ₂ -Al ₂ O ₃ ) abrasive grains, The present invention is similarly applied to the resinoid grinding wheel 10 in which superabrasive grains such as cubic boron nitride (CBN) abrasive grains and diamond abrasive grains, or a mixture thereof are used as the abrasive grains 16. Further, the grain size of the abrasive grains 16 is appropriately changed.

Further, in the above-described embodiment, the abrasive grains 16 in the entire resinoid grinding wheel 10 are the synthetic resin binder 1.
It consisted of a grindstone structure joined by 8
The present invention is similarly applied to a grinding wheel in which an outer peripheral wheel portion is provided around a core portion made of synthetic resin or metal.

Although not illustrated one by one, the present invention is implemented with various modifications within the scope of the invention.

[Brief description of drawings]

FIG. 1 is a perspective view showing the shape of a resinoid grinding wheel that is an embodiment of the present invention.

FIG. 2 is an enlarged view showing the structure of a resinoid grinding wheel that is an embodiment of the present invention.

FIG. 3 is a diagram showing a relative positional relationship between a resinoid grinding wheel and a work material in a grinding test conducted by the present inventor.

FIG. 4 is a graph showing the transition of the power consumption value of the grinding machine spindle with respect to the number of processed workpieces obtained as a result of a grinding test conducted by the present inventor.

[Explanation of symbols]

10: Resinoid grinding wheel 16: Abrasive grain 18: Synthetic resin binder

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3C063 AA02 AB03 BA02 BB03 BB07                       BC01 BC03 CC17 FF22 FF23                       FF30                 4F071 AA42 AA78 AB03 AB18 AB26                       AB27 AE13 AF20 AH19 DA17                 4J002 CD051 CD201 DA016 DE146                       DJ006 DK006 FD206 GT00

Claims (4)

[Claims] 1. A synthetic resin binder produces a particle size of # 800.
A resinoid grinding wheel constituted by the above-mentioned abrasive grains being mutually bonded, wherein the synthetic resin binder uses a main agent containing hydrogenated bisphenol A as a main raw material. Grinding wheel. 2. The resinoid grinding wheel according to claim 1, wherein the synthetic resin binder has a viscosity of 1 Pa · s or less when a main agent and a curing agent are mixed. 3. The resinoid grinding wheel according to claim 1, wherein the synthetic resin binder has a glass transition temperature of 100 ° C. or higher after curing. 4. The resinoid grinding wheel according to claim 1, wherein the synthetic resin binder has a bending elastic modulus of 2 GPa or less after curing.