JPH10296638A - Super hard abrasive grain resin bond grinding wheel and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide effective chip pockets simultaneously with manufacturing by projecting the extreme end part of an abrasive grain from bonding agent by a specific size. SOLUTION: A grinding layer forming part is provided with walls on the inner circumferential side and on the outer circumferential side, and hence a groove is formed. Molten mixed liquid is flowed in the groove extending over the full circumference. A leveling plate is laid over the upper faces of the walls on the inner circumferential side and the outer circumferential side, and is rotated over one rotation on the circumference as it is so as to level the liquid to remove surplus molten mixed liquid outside the walls. Hereby, a mixed liquid layer of uniform thickness is formed in the groove in the depth direction. This depth is favorable to be less than about two times, more favorably less than about 1.2 times the maximum diameter of the abrasive grain. Hereby the abrasive grain projects more than 2 μm from the bond, and the height of the extreme ends of many projecting abrasive grains are nearly arranged in order.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to diamond, CBN
The present invention relates to a super-abrasive resin-bonded grindstone having abrasive grains and the like and a method for producing the same, and particularly to a single-layer grindstone.

[0002]

2. Description of the Related Art Super-abrasive grindstones include resin-bonded, metal-bonded, and vitrified-bonded grindstones. All of the abrasive grains have a multilayer structure of 1 to 5 mm in thickness. Limited to electrodeposited whetstones only.

In the case of the former method, the grinding method requires special equipment such as a press furnace in addition to a mold, and requires not only molding, pressing, heating, maintaining a constant temperature, slow cooling, etc. Dressing also needs to be performed after completion, and an extremely large number of steps are required to manufacture the grindstone. In the latter case, a special plating apparatus or a plating liquid management apparatus is required to maintain the quality.

[0004]

SUMMARY OF THE INVENTION The present invention is a very simple method, without the need for special equipment and a large number of man-hours as in the past.
Moreover, it is possible to manufacture a single-layer or multi-layer super-abrasive resin-bonded grindstone.

[0005]

Means for Solving the Problems The present invention has been made to solve the above problems, and the first feature of the present invention is that the superabrasive grains held in a resin bond layer formed on a base metal are as described above. As described above, it is possible to protrude from the beginning of manufacture without performing dressing, whereby a required chip pocket can be provided. When the abrasive grains protrude higher than the binder portion, the chips are discharged well and the processing characteristics are excellent. The protrusion amount of the chips is preferably 2 μm or more. At least the abrasive grains may be held at least half of the abrasive grain diameter.

[0006] The production method is such that one or two or more resins mixed with superabrasive grains and, if necessary, a filler are melted in one or two or more solvents, and sufficiently stirred so that the superabrasive grains are uniformly dispersed. After that, the super-abrasive grains protrude from inside the resin bond in the process of evaporating the solvent and solidifying the resin by applying the composition on a grindstone base and then drying it at room temperature or by heating.

Although a thin resin bond coating may be present at the tip of the superabrasive grain, the coating at the tip is peeled off very easily due to contact with the work material at the same time as the start of the grinding process, and as a cutting edge. There is no risk of inhibiting the function of.

In the case of an electrodeposited whetstone, as shown in FIG. 1, since the abrasive grains 1 are held in contact with the surface of the base metal 2 and are held by nickel plating 3, the abrasive grains 1 The height varies. On the other hand, in the case of the present invention, as will be described in detail in the examples described later, it is found that the height of the protruding abrasive grains is uniform compared to the former by leveling the resin to a uniform thickness when the resin is in a molten state. This is the second characteristic.

The third feature is that by adding a filler to the resin melt, it is possible to improve the strength and abrasion resistance of the resin bond or select a means for imparting lubricity. In particular, it has been found that it is necessary to improve the elastic modulus of the binder and to increase the abrasive grain holding power by containing hard particles. The performance can be further improved by using superabrasive grains coated with metal, resin, vitrified or the like.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The resins used are phenolic resins, epoxy resins, polyimide resins, melamine resins,
Resins used for conventional resin-bonded grindstones such as alkyd resins, polyurethane resins, and polyester resins can be used. Alternatively, an organic resin containing a metal may be used.

The solvent is not particularly limited as long as it can dissolve the resin, but is appropriately selected depending on the type of the resin used, the abrasive grains, and the combination of the filler, and the amount of the solvent to be added is easy to apply the molten resin and uniform in thickness. Is selected in consideration of the projection height of the superabrasive grains after solidification and solidification. Preferred solvents include benzene, toluene, xylene, cresol, ethanol, acetone and the like.

As is also known in the conventional superabrasive grindstone, in the grindstone of the present invention, fine diamond, Al ₂ O ₃ , SiC, Si
O _2, to improve the strength and wear resistance by incorporating the hard particles CrO _2, and the like. Diamond, SiC and the like also have the effect of increasing the thermal conductivity of the binder. Cu, F
The same effect can be obtained by adding a metal powder such as e or Co.
Alternatively, if graphite, MoS ₂ , BN, or the like is added, the sharpness can be improved by lubricity.

However, the greatest disadvantage of the single-layer resin-bonded grindstone is that a sufficient effect cannot be exerted due to the falling off of abrasive grains. The most important factor in exhibiting the performance of a single-layer resin-bonded grindstone is the abrasive holding power. To do that,
It has been found that it is effective to fill the resin with one or more of the above hard particles in a required amount and increase the elastic modulus of the binder to a specific value or more. Although the elastic modulus of the binder varies depending on the type, particle size, and content of the filler, as a result of the grinding test under various conditions, if the abrasive is 350 kgf / mm ² or more, a grinding wheel with less abrasive grains falling out and excellent grinding performance can be obtained. Obtained.

[0014]

EXAMPLES # 120 (100 to 14) was added to phenol resin.
0 μm) diamond and # 1000 as filler
Was mixed in a volume ratio of 60:25:15, and the mixture was added to cresol (the same weight as the phenol resin) prepared as a solvent, and the resin was dissolved and mixed so that the whole was uniform.

A cup-shaped iron base shown in FIG. 2 was prepared. The grinding layer forming section 10 has walls 11 and 1 on the inner and outer peripheral sides.
1 ′ was provided, thereby forming a groove 12 having a groove width W and a depth T.

The above-mentioned molten mixture was poured into the groove 12 over the entire circumference. A leveling plate was laid over the upper surfaces of the inner and outer peripheral walls 11 and 11 ', and was rotated one or more turns on the circumference as it was to remove excess molten mixture outside the walls.
As a result, a mixed liquid layer having a depth T and a uniform thickness was formed in the groove 12.

In particular, the depth T is a very important factor in relation to the abrasive grain size. If any of the abrasive grains has a particle size larger than the depth T, the abrasive grains hit the leveling plate during the leveling operation and roll in the groove to hinder the leveling operation. At least, T must be at least the same depth as the maximum diameter in the variation of the abrasive grain size. However, in order to manufacture a single-layer resin-bonded grindstone, if T is made too large, the abrasive grains protruding from the surface This is because the number is reduced and the number of the tips having the same height is reduced. Therefore, the depth T is preferably not more than twice the maximum abrasive grain size, more preferably not more than 1.2 times.

In the embodiment, the depth T is set to 160 μm. The base metal from which the molten mixture in the groove 12 was leveled was dried and cured in a nitrogen atmosphere at 170 ° C. for 30 minutes. By cutting and removing the walls 11, 11 ', a cup-type resin-bonded single-layer grindstone was obtained.

As a result of the leveling operation, as shown in FIG. 3, the tips of many abrasive grains are flush with the leveling surface. In the case of the embodiment, the volume of the solvent occupies 44% of the total volume of the molten mixture, and the amount of the solvent evaporates accordingly, so that the thickness of the resin layer is reduced by about 40% from the beginning. As a result, as shown in FIG. 3B, the abrasive grains protrude from the bond, and the tip heights of the many protruding abrasive flows are almost uniform.
However, if it takes time to solidify, the abrasive grains slightly sink due to the specific gravity difference between the abrasive grains and the molten resin. Therefore, it is desirable to increase the viscosity of the mixed solution or to shorten the heating and solidifying time.

In the first embodiment, the groove is formed in the grinding layer forming portion in advance to take a means for making the molten mixed solution uniform in thickness. However, even if the groove is not formed, the surface of the grinding layer forming portion may be formed on the flat surface. Alternatively, there is a method in which the entire surface is pressed with a leveling plate before curing.

In the case of a straight-type grindstone, the molten mixed solution can be applied to a grinding layer forming portion on the outer periphery, and can be smoothed by pressing a rotating roller before curing. The thickness of the abrasive layer can be controlled by providing an interval between the leveling plate or roller and the grinding layer forming section.

The method of manufacturing a single layer has been described above. However, after the mixed solution is solidified, the mixture is applied again and solidified a plurality of times to form a laminated grindstone.

In the above-described embodiment, a molten mixture of resin and abrasive grains is applied to the base metal to form a grindstone. However, a molten resin obtained by melting the resin in a solvent is applied to the base metal and the abrasive grains are solidified before the solidification. The method of spraying or hand-setting and pressing with a leveling plate is also effective.

[0024]

As described above, according to the present invention, an unprecedented single-layer superabrasive resin-bonded grindstone can be manufactured by a simple method without requiring special equipment or a large number of steps. Also, dressing is not required, and the tip of the abrasive grains protrudes from the binder, so that an effective chip pocket can be present at the same time as manufacturing.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a state of a grinding surface of a conventional electrodeposition grinding wheel.

FIG. 2 is a sectional view of a grindstone base metal used in an embodiment of the present invention.

FIG. 3 is a schematic view showing a grinding surface state of a grinding wheel according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Abrasive grain 2 Base metal 3 Nickel plating 4 Resin 10 Grinding layer forming part 11, 11 'wall 12 Groove T Groove depth W Groove width

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideki Ogawa 2-80 Houkita-cho, Sakai-shi, Osaka Inside Osaka Diamond Monde Industry Co., Ltd.

Claims (5)

[Claims] 1. A grindstone composed of superabrasives, a filler and a resin, wherein the abrasive surface of the grindstone protrudes by 2 μm or more from a binder regardless of dressing. Resin bond single layer whetstone. 2. The resin-bonded superabrasive single-layer whetstone according to claim 1, wherein the elastic modulus of the binder comprising the resin and the filler is 350 kgf / mm ² or more. 3. A resin solution containing superabrasive grains and, if necessary, a filler, is applied to a grinding layer forming portion of a grindstone base metal, and after being made uniform in thickness, is solidified by heating. A method for producing a superabrasive resin-bonded grindstone, characterized in that it is projected. 4. A method in which a resin solution containing superabrasive grains and a filler as necessary is applied to a grinding layer forming portion of a grinding wheel base metal, uniformized in thickness, heated and solidified, and then repeatedly applied and solidified thereon. A method of manufacturing a laminated resin-bonded grinding wheel. 5. A method for producing a resin-bonded single-layer grindstone, which comprises applying a resin solution to a grinding layer forming portion of a grindstone base metal and spraying or hand-setting superabrasive grains before solidification.