JP3314213B2 - Resinoid grinding wheel and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to mechanical parts, mold parts,
The present invention relates to a surface abrasive used in a process of manufacturing electric / electronic parts, a resinoid grinding wheel for cutting, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, there has been used a method in which alumina or the like is used as abrasive grains, and a thermosetting resin such as a phenol resin is used as a binder, mixed, molded, and then cured at 150 to 200 ° C. Have been. The structure of the resinoid grindstone is expressed by the distribution of the abrasive grains, the binder and the pores, and the porosity is naturally determined by determining the abrasive grain rate and the binder rate in the total volume of the grindstone. . Further, the porosity largely depends on the degree of the mold clamping pressure at the time of pressure molding through the kneading process of the abrasive grains and the thermosetting resin. As a method of intentionally forming pores, a method of carbonizing at a temperature of 180 to 200 ° C., such as walnut powder or acorn powder, is only partially observed. Walnut powder and acorn powder are not perfect, and some may remain without carbonization.Depending on the size of pores and the degree of pores, inhibition of the autogenous action of the abrasive cutting edge and chips embedded in the pores It has various problems such as clogging phenomenon.

[0003] The sustainability (lifetime) of the sharpness of the resinoid grindstone depends on how long the autogenous blade action due to wear, crushing and falling off of the abrasive cutting edge is maintained. That is, pores are one factor relating to the problem of the life of the grinding wheel.

In the case of vitrified grinding stones, wood powder, acrylic resin, styrene resin, polyester resin, naphthalene, camphor, hydrogen peroxide and the like are used as pore agents, and the range of choice of pore agents is large. On the other hand, in the resinoid grindstone, the pore material is limited to walnut powder, acorn powder, and the like that are carbonized at a temperature of 180 to 200 ° C., and the width of the pore material selection is small, and it is difficult to make the pore size uniform. It is a problem.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have called for a pseudo-porous agent having the same action as a pore instead of the conventional pore agent, and have studied variously to extend the life of a resinoid grindstone. . As a result, they found that melamine cyanurate was excellent as a pseudo-porous agent, and completed the present invention.

An object of the present invention is to provide an abrasive grain size, a grinding wheel hardness,
An object of the present invention is to provide a resinoid grindstone having a simple structure having a longer service life than a conventional grindstone by providing a pseudo-porous agent while having the same degree of bonding and the like, and a method of manufacturing the same.

[0007]

That is, the present invention relates to a resinoid grinding wheel characterized in that melamine cyanurate is dispersed. Further, the present invention provides a method for producing a resinoid grindstone in which abrasive grains and a binder are mixed, molded, and then heated and cured, wherein melamine cyanurate is added after the abrasive grains and the primary binder are mixed. And a method of manufacturing a resinoid grindstone.

Hereinafter, the present invention will be described in more detail. Melamine cyanurate used in the present invention is an adduct of melamine and cyanuric acid, which is known as a flame retardant for nylon and the like, and is easily available. When used as a pseudoporous agent in the present invention, melamine cyanurate can be used in powder or granules, preferably,
It is preferred that the average particle size is similar to or slightly smaller than the particle size of the abrasive used.

As the abrasive grains, conventionally known oxides such as alumina and silicon oxide, carbides such as silicon carbide, and nitrides such as silicon nitride and titanium nitride are used. Further, additives such as sulfide ore, carbon, cryolite and the like may be blended in order to improve the grinding performance. It is preferable to mix these components before adding melamine cyanurate.

As the binder, a thermosetting resin such as a phenol resin used in the production of a conventional resinoid grindstone is used. The resin may be used in the form of a powder or a liquid, but a method using a liquid is preferable because it increases the dispersibility of melamine cyanurate. Further, after the addition of melamine cyanurate, it is preferable to use a thermosetting resin such as a phenol resin as the secondary binder in order to further enhance the dispersibility of melamine cyanurate. In this case, the phenol resin or the like is more preferably used in a powder form.

In the present invention, the amount of melamine cyanurate is from 1 to 100 parts by weight, preferably from 1 to 50 parts by weight, per 100 parts by weight of the abrasive grains. If the amount is less than 1 part by weight, the effect of the present invention cannot be sufficiently exhibited, and
If the amount exceeds the weight part, the strength of the grindstone is undesirably reduced.

After mixing and mixing as described above, the resinoid grindstone of the present invention can be manufactured by a usual method. That is, the composition is first molded and then heated to cure the resin after molding. As the molding method, pressure molding such as press molding is usually used. The heating temperature for curing is usually 150
~ 200 ° C. In this temperature range, melamine cyanurate does not decompose or vaporize.

[0013]

FIG. 1 shows a model diagram of the mechanism of the resinoid grindstone in which melamine cyanurate of the present invention is dispersed. In the grindstone of the present invention, when used for grinding, melamine cyanurate itself (3) is immersed in water. Do not dissolve. However, in the case of wet grinding, it is considered that the material softens when it comes into contact with water, and peels off in the size of primary particles (about 1 μm) during grinding.

Further, by the action of the cutting force, the melamine cyanurate itself on the surface also partially falls off and wears,
It remains as a pseudo pore. In addition, micro-peeling occurs on the surface and the surface of melamine cyanurate near the surface during grinding.
These facts lead to crushing or falling off of the abrasive grains (1), generate a new cutting edge, and promote a self-generated cutting action for maintaining a sharp cutting state. At the same time, in addition to preventing the clogging phenomenon in which chips or the like are clogged in the pores of the grindstone, clogging due to the adhesion of chips to the surface of the melamine cyanurate does not occur due to the surface peeling of the melamine cyanurate. Furthermore, the workpiece is locally heated, which leads to a burning phenomenon in which the workpiece is discolored and deteriorated, prevention of formation of a damaged layer, and the like.

That is, the feature of the present invention resides in that melamine cyanurate which is softened without being dissolved in the grinding fluid and which peels off and falls off is used as a pseudo-porous agent. Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

[0016]

【Example】

Example 1 10 kg of white alumina (WA # 46) as abrasive grains and 0.3 kg of sulfide ore, carbon and cryolite as additives for improving grindability were mixed. After completion of mixing, 0.4 kg of liquid phenol resin was mixed as a primary binder.
And granules of melamine cyanurate (average particle size 200 ~
(400 μm) 0.5 Kg was added and mixed. Further, 1 kg of a powdered phenol resin was mixed as a secondary binder.

The obtained mixture was placed in a mold having an outer diameter of 210 mm, an inner diameter of 50.8 mm, and a thickness of 25 mm, and was molded by using a press. After pressing, remove the molded product from the mold,
It was kept at 70 to 190 ° C. for 30 hours and thermally cured. After cooling, the cured product was cut into an outer diameter of 205 mm to prepare a grinding wheel for surface grinding for evaluation.

For comparison, a grindstone was produced in the same manner as in Example 1 without using melamine cyanurate, and a surface grinding grindstone (WA # 46L6B) for comparative evaluation was produced. Then, each grinding wheel was evaluated as follows under the following grinding conditions.

The evaluation was performed by using the melamine cyanurate-containing grindstone obtained in the examples (hereinafter abbreviated as MC-containing grindstone) and a comparatively prepared melamine cyanurate-free grindstone, and applying acceleration to the spindle head of the grinder. The sensor was attached, and the vibration during grinding was measured, as well as the tangential and normal grinding forces. The evaluation results are shown in FIGS. 2, 3 and 4.
Shown in

[0020]

[Table 1]

FIG. 2 shows the measurement results of the vibration acceleration of the vertical component on the grinding wheel drive shaft of the grinding wheel with MC and the grinding wheel with no additive according to the present invention with respect to the grinding amount. The solid line (5) indicates the case of the grinding wheel with MC, and the broken line (6) indicates the case of the non-added grinding wheel. In the case of the grindstone of the present invention, the acceleration G is maintained at about 0.2 to 0.3 G before showing a sharp rise, and the grinding amount is about three times as much as that of the non-added grindstone,
It shows the persistence of sharpness. This means that the sharpness of the grindstone is extended about three times that of the conventional additive-free grindstone.

Further, dressing work with diamond is required at about 1.5 G when the acceleration G is in a saturated state. However, in the case of a grindstone containing MC, the dressing work interval is longer than that of a conventional non-added grindstone. , Which means that the number of dressings is reduced.

FIG. 3 shows the measurement results of the grinding resistance and the maximum grinding fluctuation resistance in the tangential direction of the grinding wheel and the additive-free grinding wheel of the present invention with respect to the grinding amount. Solid line (7)
And the one-dot broken line (9) show the measured values of the tangential grinding resistance and the maximum grinding fluctuation resistance for the grindstone of the present invention, respectively. A broken line (8) and a two-dot broken line (10) show the grinding resistance value and the maximum grinding fluctuation resistance value in the case of the non-added grinding wheel, respectively. Each of the grindstones of the present invention has a lower resistance value than the non-added grindstone. In the case of the non-added whetstone, the maximum grinding fluctuation resistance reaches around 2500 N at the maximum.

FIG. 4 shows the measurement results of the grinding resistance and the maximum grinding fluctuation resistance in the normal direction of the grinding wheel and the non-addition grinding wheel of the present invention with respect to the grinding amount. Solid line (1
1) and the one-dot broken line (13) indicate the measured values of the grinding resistance and the maximum grinding fluctuation resistance in the normal direction for the grindstone of the present invention, respectively. The broken line (12) and the two-dot broken line (14) show the measured values of the grinding resistance and the maximum grinding fluctuation resistance in the normal direction for the non-added whetstone, respectively. Similar to the tangential measurement, the whetstone of the present invention has a lower resistance.

[0025]

The resinoid grindstone containing melamine cyanurate of the present invention can extend the life of the grindstone by maintaining the sharpness of the grindstone longer than that of the conventional grindstone. In addition, by increasing the dressing interval, highly efficient grinding can be performed. Further, the resinoid grindstone is capable of preventing the burning phenomenon of a work material and the generation of a deteriorated layer due to a reduction in grinding resistance.

[Brief description of the drawings]

FIG. 1 is a model diagram of a mechanism of a grindstone of the present invention.

FIG. 2 is a comparison diagram of the vibration acceleration of the vertical component of the grinding wheel of the present invention and the grinding wheel with no additive on the grinding drive shaft.

FIG. 3 is a comparison diagram of a grinding resistance value and a maximum grinding fluctuation resistance value in a tangential direction between the grindstone of the present invention and an additive-free grindstone.

FIG. 4 is a comparison diagram of a grinding resistance value and a maximum grinding fluctuation resistance value in a normal direction of the grinding wheel of the present invention and a non-added grinding wheel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Abrasive grain 2 ... Binder + additive 3 ... Melamine cyanurate grain 4 ... Porosity 5 ... Whetstone of the present invention 6 ... Non-additive whetstone 7 ... of the present invention Grinding resistance in the tangential direction of the grinding wheel 8: Grinding resistance in the tangential direction of the non-added whetstone 9: Maximum grinding fluctuation resistance in the tangential direction of the whetstone of the present invention 10: Maximum grinding fluctuation in the tangential direction of the non-added whetstone Resistance 11: Grinding resistance in the normal direction of the grindstone of the present invention 12: Grinding resistance in the normal direction of the additive-free grindstone 13: Maximum grinding fluctuation resistance in the normal direction of the grindstone of the present invention 14.・ Maximum grinding fluctuation resistance in the normal direction of the additive-free grinding wheel

Continued on the front page (72) Inventor Makoto Takakura 635 Sasakura, Funaka-cho, Togane-gun, Toyama Prefecture Nissan Chemical Industry Co., Ltd. (56) References JP-A-6-39731 (JP, A) JP-A-3-287380 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B24D 3/28 B24D 3 / 00 340 B24D 3/02 310

Claims (4)

(57) [Claims] 1. A resinoid grindstone in which melamine cyanurate granules are dispersed, wherein the melamine cyanurate granules have a property of peeling off from the grindstone by contact with water during polishing. . 2. The resinoid grinding wheel according to claim 1, wherein the average particle diameter of the melamine cyanurate granules is equal to or slightly smaller than the particle diameter of the abrasive grains. 3. A method for producing a resinoid whetstone in which abrasive grains and a binder are mixed, molded and then heated and cured, wherein melamine cyanurate granules are added after the abrasive grains and the binder are mixed and before molding. The method for producing a resinoid grindstone according to claim 1, wherein: 4. The method for producing a resinoid grindstone according to claim 2, wherein after addition of the melamine cyanurate granules, a thermosetting resin is added and mixed as a secondary binder.