JP3350459B2 - Manufacturing method of composite whetstone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding surface for grinding a material to be ground, which comprises a plurality of vitrified grinding wheels and a resinoid grinding wheel provided so as to fill a space between the plurality of vitrified grinding wheels. a method for producing a composite <br/> abrasive stones being.

[0002]

2. Description of the Related Art Conventionally, when a vitrified grinding wheel is used for surface grinding of a material to be ground or a difficult-to-cut material represented by aluminum or the like in which the contact area of the grinding wheel is large as in the case of thickness grinding of a blade, for example. In addition, scorching easily occurs on the ground surface of the material to be ground due to the grinding heat generated during the processing.
Therefore, the grinding wheel used for such processing usually has a structure in which a segmented vitrified grinding wheel is attached at a predetermined interval on a base such as a metal disk, or a groove is formed in the grinding plane of the vitrified grinding wheel on the disk. Whetstones with different structures are used. One of the drawbacks of grinding wheels with such a structure is that the segmented vitrified grinding wheel and the edges of the grooves with grooves are easily chipped due to grinding resistance, and this chipping makes the material to be ground stable. There was a problem that it could not be sharpened.

On the other hand, there has been proposed a composite grindstone having a structure in which a groove portion of a vitrified grindstone and the periphery of a segment-shaped vitrified grindstone are reinforced with a resinoid grindstone. For example, a grindstone described in Japanese Patent Application Laid-Open No. 2-292178 is one example.

[0004]

However, since the resinoid grindstone conventionally used has a high fluidity, this portion is densified, which causes grinding burns and clogging of chips during grinding.
There is a problem that welding and the like are easily generated, and the excellent grinding performance of the vitrified grinding wheel cannot be sufficiently brought out. In order to prevent this, a hollow pore material (called a balloon or a bubble) made of an inorganic compound or a resin, or a pore forming material such as a soft granulated filler or foamed styrene beads is used to remove abrasive grains, It is considered to mix with a fluid grindstone material composed of a liquid resin binder to form a large number of pores in the grindstone.However, in the method using such a pore-forming material, a solid material is formed in the liquid resin. In order to uniformly disperse, the amount of the pore-forming material added is limited, and the porosity cannot be sufficiently increased. For example, in the case of grinding a difficult-to-cut material such as a composite material (MMC) of aluminum and SiC, grinding is still performed. Grinding burn and welding of vitrified whetstone,
Chipping was apt to occur, and the performance of the vitrified grindstone could not always be sufficiently brought out.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to sufficiently prevent the vitrified grinding wheel from welding or chipping to sufficiently obtain the excellent grinding performance of the vitrified grinding wheel. Is to be able to

[0006]

[0007]

[0008]

In order to achieve the above object,
For the first invention , a grinding wheel for grinding a material to be ground has a vitrified grinding wheel portion and a porous resinoid grinding wheel portion provided so as to fill around the vitrified grinding wheel portion. A manufacturing method,
(a) a vitrified grindstone manufacturing process for fabricating the vitrified grindstone portion, and (b) abrasive particles, a liquid resin acting as a binder, and a fluid grindstone material containing a surfactant were stirred to create a number of bubbles. By pouring and curing around the vitrified grindstone portion in the state, the porous resinoid grindstone portion having a large number of pores due to the bubbles was manufactured and simultaneously fixed integrally to the vitrified grindstone portion and poured. liquid resin flowable grinding material possess a resinoid grindstone production and fixing step to reinforce the vitrified abrasive part by curing impregnated in the pores of the vitrified grinding wheel portion, and its
The resinoid grindstone fabrication / fixing process is often performed by (b-1) stirring.
The flowable grindstone material in which a number of bubbles are created
Pour it to approximately the same height as the
The liquid resin is contained in the pores from the side of the
A first pouring step of dipping, and (b-2) the liquid resin is
While being substantially impregnated from the side of the vitrified whetstone,
The vitrified grinding stone part
A second pouring step for further pouring the dynamic grindstone material, and (b-3)
The upper surface of the vitrified whetstone part is exposed and
Of the vitrified whetstone part and the resinoid whetstone part
Remove the extra resinoid grindstone so that the top surface is almost flush.
And a removing step for removing.
You.

A second invention is a grinding surface for grinding a material to be ground.
Is the vitrified whetstone part and its vitrified whetstone part
Porous resinoid grinder provided to fill around
And a method for producing a composite whetstone comprising a stone part.
(A) a vitrifier for manufacturing the vitrified whetstone part;
Fido grinding wheel manufacturing process and (b) acts as abrasive grains and binder
Liquid resin, and fluid grinding wheel material containing surfactant
Is stirred, and a large number of bubbles are created.
By pouring around the id whetstone part and curing it,
The porous resino having a large number of pores due to the bubbles
The vitrified whetstone is manufactured at the same time when the
Fluidized abrasive fixed to the part and poured
Liquid resin of stone material is vitrified by vacuum defoaming
Hardening by forcibly impregnating the pores of the whetstone
Resinoid that reinforces its vitrified grinding wheel
It is characterized by having a grinding wheel production / fixing step.

[0010]

[0011]

[0012]

According to the first aspect of the present invention, the fluidized grindstone material constituting the resinoid grindstone portion is agitated to flow around the vitrified grindstone portion in a state in which a large number of air bubbles are created, and is hardened and fixed. Since the liquid resin of the abrasive grindstone material is impregnated into the pores of the vitrified grindstone part and reinforced, the resinoid grindstone part is manufactured separately and fixed to the vitrified grindstone part with an adhesive or the like,
The number of steps is reduced as compared with a case where the vitrified grindstone portion is impregnated with a liquid resin in another step, and the manufacturing cost is reduced.

Further, since the liquid resin is impregnated in the pores of the vitrified grindstone portion and hardened, the vitrified grindstone portion is reinforced, so that chipping (such as chipping) of the vitrified grindstone portion due to welding or the like is effectively prevented. At the same time as grinding wheel wear due to grinding is suppressed,
The grinding wheel life is improved. As a result, in combination with the porous resinoid grinding wheel portion, the grinding performance of the composite grinding wheel is improved in a well-balanced manner. For example, in grinding of difficult-to-cut materials such as a composite material of aluminum and SiC, grinding burn and welding of the grinding wheel are suppressed. At the same time, chipping of the vitrified grindstone portion due to welding or the like is effectively prevented, and grinding performance and durability (grinding wheel life) sufficiently satisfactory for practical use can be obtained.

Further, the flowable grinding material in the first flow included steps pouring to substantially the same height as the vitrified grinding wheel portion, after the liquid resin is impregnated into the pores from the side surface of the vitrified abrasive portion, the second stream included steps Since the flowable grindstone material is further poured so that the vitrified grindstone portion is buried to the upper surface, in the first pouring step, the air in the vitrified grindstone portion can escape from the upper surface, and the liquid resin can be favorably introduced into the pores. In addition to the impregnation, the liquid resin is impregnated in the pores near the upper surface in the second pouring step. Thereby, the liquid resin can be sufficiently impregnated into the pores of the vitrified grindstone portion, and desired strength and wear resistance can be obtained. In addition, the incorporation of bubbles into the boundary between the vitrified grinding wheel and the resinoid grinding wheel is also suppressed.

[0015]

Here, it is desirable that the vitrified grindstone portion uses superabrasive grains such as CBN (cubic boron nitride), diamond, or a mixture thereof as abrasive grains. The superabrasives preferably have a Knoop hardness of 3000 or more, and the concentration of the abrasives is 10 to 230, preferably 20 to
The range of 180 is appropriate, and the porosity is suitably in the range of 20% to 75%, preferably 30% to 65%. The particle size of the superabrasive can be appropriately selected according to the purpose of use.
(Average particle size 220 μm) to $ 800 (average particle size 20 μm)
m) is desirable. Plurality of pores has been communicated with each other, the liquid-form resin is caused to satisfactorily impregnated.

The vitrified binder is suitable when superabrasive grains are used as the abrasive grains, for example, borosilicate glass,
It is desirable to use crystallized glass. Examples of the crystallized glass include those that precipitate willemite. In order to make the holding power sufficient, the thermal expansion coefficient of the superabrasive is ± 2 × 1 in a temperature range from room temperature to about 500 ° C.
It is desirable to be about 0 ^-6 (1 / ° K). The binder ratio can be appropriately selected, for example, 15 to 35% by volume in the state of a grindstone.
It is better to be within the range. Although it is desirable that the aggregate contains an inorganic hollow substance, ceramic particles having a softening point higher than that of the vitrified binder may be mixed as the aggregate.

The vitrified grindstone portion is composed of, for example, a large number of vitrified grindstones of substantially the same height which are fixed to each other on a flat grindstone fixing surface of a base and are fixed with an adhesive such as epoxy resin. A grooved surface may be provided on the ground surface of one vitrified grinding wheel.

The type of the abrasive grains and the binder in the resinoid grindstone portion are determined, for example, so that they are worn at the same speed as the vitrified grindstone portion and do not generate a step, and the abrasive grains such as alumina and silicon carbide are used. Usually, abrasive grains are preferably used, and as the binder, a two-pack epoxy resin obtained by mixing an epoxy resin base such as bisphenol A and an epoxy resin curing agent such as a polyamide resin is preferably used. The abrasive grains of the resinoid grindstone portion are mixed so as to obtain an appropriate wear rate similar to that of the vitrified grindstone portion, and high grinding performance is not necessarily required, and grinding may be performed mainly by the vitrified grindstone portion. . In addition, as abrasive grains of the resinoid grindstone portion, diamond abrasive grains or CBN
Super-abrasive grains such as abrasive grains can be used, and a one-part epoxy resin, a liquid phenol resol or urethane resin, polyvinyl alcohol, or the like can be used as the liquid resin.

When the liquid resin is composed of an epoxy resin, a cationic or nonionic surfactant is preferably used. For example, a nonionic surfactant (nonionic) having a concentration of about 70% is used. For example, polyoxyethylene stigulphenyl ether is used. Epoxy resin reacts with an anionic surfactant to promote curing, so that it is difficult to form a sufficient amount of bubbles during stirring, so other surfactants, ie, cationic or nonionic Surfactants are preferred. That is,
The type of the surfactant used in the present invention is not particularly limited, and nonionic (nonionic) surfactants such as fatty acids, non-fatty acids, and amides, and anions (anions) such as alkylbenzene sulfonates are used. A variety of surfactants, such as a system, a cation (cation) system, and a zwitterion system, can be used. However, considering the type of the liquid resin, it is preferable to use one having a reactivity as low as possible. It is desirable.

The fluid grinding wheel material is, for example, 40 to 8
A mixture of 0% by weight of abrasive grains, 20 to 60% by weight of a liquid resin, and 1 to 10% by weight of a surfactant based on the total thereof is preferably used. In this manner, a porous resinoid grindstone having a desired porosity and a high porosity of about 40 to 60% by volume can be obtained. At this time,
The specific gravity of the porous resinoid grindstone is about 0.8 to 1.8. The area ratio between the vitrified grindstone portion and the resinoid grindstone portion on the grinding surface is determined by a porosity such that chips are sufficiently contained in the pores of the resinoid grindstone portion and grinding burns and welding do not pose a practical problem. It is desirable to set in consideration of.

In the first pouring step of the first invention, it is sufficient to simply impregnate the liquid resin by capillary action or the like, but if necessary, forcibly impregnate the liquid resin into the pores by performing a vacuum defoaming treatment or the like. Is also possible. The degree of impregnation of the vitrified grindstone portion is appropriately determined, and it is not necessary to impregnate the inside of the vitrified grindstone uniformly.

In addition, the composite grindstone of the present invention is difficult to cause grinding burns and welding, for example, composite materials (MMC) such as aluminum and SiC, aluminum and alumina, aluminum alloys such as aluminum and high silicon aluminum, and stainless steel. It is preferably used in the case of performing a grinding process on a work material. However, it is needless to say that the present invention can also be used in a grinding process of a work material in which grinding burn and welding are relatively unlikely to occur.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the dimensional ratios and the like of each part are not necessarily drawn accurately. FIG. 1 is a perspective view of a composite grindstone 10 according to one embodiment of the present invention, and FIG. 2 is a plan view and a longitudinal sectional view. The composite grindstone 10 is used for double-sided surface grinding such as knife thickness grinding, has a thick cylindrical shape, and has an outer diameter of 355.
mm, inner diameter is about 250mm, thickness (height) is 12
About 0 mm, an annular base metal 12 serving as a base, and a large number of vitrified grinding wheels 14 of substantially the same height fixed and separated from each other on a flat whetstone fixing surface 12s of the base metal 12, The vitrified grindstone 14 is provided to fill the space around the vitrified grindstone 14 and a porous resinoid grindstone 16 having substantially the same height dimension. The flat grinding surface 10 s, which is the upper end surface, is constituted by a number of vitrified grinding wheels 14 and a resinoid grinding wheel 16 buried therearound, and the circular portion on the upper surface of the number of vitrified grinding wheels 14 is a vitrified grinding wheel. The upper surface portion of the resinoid grindstone 16 filling the periphery of the portion corresponds to the resinoid grindstone portion. A small outward flange 12f is integrally provided at the end of the base 12 opposite to the grinding wheel fixing surface 12s. As the base metal 12, for example, low thermal expansion aluminum is preferably used, but ordinary steel may be used.

The vitrified grindstone 14 comprises (a) diamond abrasive grains (# 100 / # 120); 31.3% by volume (b) inorganic hollow material balloon (110-150 μm); 14.6% by volume (c) vitrified bonding 26.7% by volume (d) Pores; Residue, a large number of interconnected pores impregnated with a two-part epoxy resin. The diamond abrasive has a Knoop hardness of 3000 or more, the concentration of the abrasive is about 125, and the porosity is about 27%. Examples of the vitrified binder include borosilicate glass and crystallized glass. The thermal expansion coefficient of diamond abrasive grains is ± 2 × 10 ⁻⁶ (1 / ° K) in a temperature range from room temperature to about 500 ° C.
The degree is used. This vitrified whetstone 14
Each have an outer diameter of about 20 mm and a thickness (height) of 5 mm
It has a cylindrical shape and is fixed to the grindstone fixing surface 12s with an epoxy resin adhesive at one end surface.

The porous resinoid grindstone 16 is shown in FIG.
(a) As shown in an enlarged view of a part of the surface, the structure is such that alumina abrasive grains (WA) 20 of about 220 are bonded by an epoxy resin 22 as a binder, and are distributed substantially uniformly in the structure. A large number of independent pores 24 having a diameter of about 0.1 to 1 mm are provided. The abrasive grain ratio of the porous resinoid grindstone 16 is about Vg ≒ 25%, and the binder rate is Vb =
About 30%, the porosity is about Vp = 45%, and the specific gravity is 1.
About 2. FIG. 3B is a structural diagram of a normal resinoid grindstone.

Next, a method of manufacturing such a composite whetstone 10 will be described. FIG. 4 is a view for explaining a basic manufacturing process. In the vitrified grinding wheel manufacturing process of the process 1, the diamond abrasive grains (# 100 / # 120), an inorganic hollow material balloon as an aggregate, a vitrified binder and the like are mixed in a predetermined manner. A large number of vitrified grindstones 14 are produced by press-molding the grindstone material blended in the proportions and firing at 900 ° C. for 5 hours. FIG. 5 shows one vitrified whetstone 1
FIG.

In the vitrified grindstone fixing step of the step 2, a number of the vitrified grindstones 14 manufactured in the step 1 are fixed.
As shown in FIG. 6, each is attached to a predetermined position on the grindstone fixing surface 12s of the base metal 12 with an epoxy resin adhesive. Step 2 corresponds to a vitrified grinding wheel manufacturing step together with step 1. FIG. 6A is a plan view, and FIG.
Is a longitudinal sectional view, and a number of vitrified grinding wheels 14 are regularly arranged at regular intervals around the center line of the base metal 12.

In the step 3 of manufacturing and fixing the resinoid grindstone, as shown in FIG. 7, molds 36 and 38 are attached to the outer peripheral side and the inner peripheral side of the annular base metal 12, respectively, so that An annular groove is formed, and a fluid grindstone material 40 of the resinoid grindstone 16 is poured into the groove so as to fill the periphery of the vitrified grindstone 14 and, after being cured, an extra resinoid so as to be flush with the upper surface of the vitrified grindstone 14. The grindstone 16 is removed. FIG. 8 is a process chart for more specifically explaining the resinoid whetstone manufacturing / fixing process. First, (a) alumina abrasive grains (WA) (# 220); 70.0% by weight (b) epoxy resin base material; 21.0% by weight (c) epoxy resin curing agent; 8.0% by weight (d) surfactant; 1.0% by weight was prepared and put into a stirrer in the stirring step of Step 3-1 to obtain, for example, 3% by weight. Stir and mix for a predetermined time of about a minute. Thus, the alumina abrasive particles 20 are contained in a liquid resin (epoxy resin 22) composed of an epoxy resin base material and an epoxy resin curing agent.
And a fluidized grindstone material 40 mixed with a surfactant is formed, and air is entrained in the fluidized grindstone material 40 to generate a large number of air bubbles.
Is solid (abrasive 20), liquid (resin and surfactant),
And a gas (bubble).

As the epoxy resin main agent, for example, bisphenol A or the like is used, and as the epoxy resin curing agent, for example, a polyamide resin or the like is used. As the surfactant, for example, a nonionic type (nonionic) polyoxyethylene stigulphenyl ether having a concentration of about 70% is used. When such a two-component epoxy resin is used as the epoxy resin 22, the base resin and the curing agent are mixed in a stirrer prior to the stirring step, and then the surfactant and the alumina abrasive grains 20 are sequentially charged. Is done. However, the order of adding the surfactant and the alumina abrasive grains 20 may be any order. The above stirring time is
The setting is such that the alumina abrasive grains 20 are uniformly dispersed and a desired foaming state is obtained.

In the first pouring step of the step 3-2, as shown in FIG. 7A, the flowable grindstone material 40 and the vitrified grindstone 14 are substantially filled in the annular groove surrounded by the molds 36 and 38. Pour to the same height. At this time, vitrified whetstone 1
4 so that the air in the pores of the vitrified grindstone 14 escapes from the upper surface of the vitrified grindstone 14, the liquid resin of the fluid grindstone material 40, that is, the two-liquid epoxy resin 22 Satisfactorily impregnates the pores from the side of the pores.

In the subsequent second pouring step 3-3, after a lapse of a predetermined time during which the epoxy resin 22 is substantially impregnated from the side surface of the vitrified grindstone 14 by capillary action in the first pouring step, (b) of FIG. ), The flowable grindstone material 40 so that the vitrified grindstone 14 is filled up to the upper surface.
Pour more. The impregnation state of the epoxy resin 22 before performing the second pouring step does not necessarily need to be uniformly impregnated into the interior of the vitrified grindstone 14, and in this embodiment, about 30 minutes have passed after the first pouring step. A second pouring step is performed later. The flowable grindstone material 40 is poured into the upper surface of the vitrified grindstone 14 in the second pouring step, so that the epoxy resin 22 also impregnates the pores of the vitrified grindstone 14 from the upper surface.

By pouring the flowable grindstone material 40 in the two steps, the pores of the vitrified grindstone 14 are sufficiently impregnated with the epoxy resin 22 and cured in the next curing step (step 3-4) and the like. By doing so, the vitrified grindstone 14 is reinforced and predetermined strength and wear resistance can be obtained. In addition, vitrified whetstone 14
Between the resin and the resinoid grindstone 16, especially the grindstone fixed surface 12s
The entry of air bubbles into the inner corner portion on the side (bottom side) and the like is also well avoided.

In the curing step of step 3-4, the epoxy resin 22 is cured by being left at room temperature for about 12 hours. Here, since the fluid grindstone material 40 foamed in the stirring process contains a surfactant,
Air bubbles do not disappear during the pouring step, the second pouring step, and the curing step, and the foaming state at the end of stirring is maintained. Therefore, at the end of curing, many pores 24 derived from air bubbles are formed in the structure of the porous resinoid grindstone 16 (strictly in the epoxy resin 22) as shown in FIG. . In addition, since no pressure is applied to the fluid grindstone material 40 in the process from the pouring to the hardening, the pores 24 are formed in the shape of the bubbles generated in the stirring step.

After the curing is completed as described above, Step 3
In the heat treatment step 5, a heat treatment (aftercure) is performed at a temperature of, for example, about 150 ° C. In the flushing step 3-6, the upper surface of the vitrified grindstone 14 is exposed as shown in FIG.
By removing excess resinoid grindstone 16 by grinding or the like so that the upper surface of resinoid grindstone 16 is flush (continuous flat surface), target composite grindstone 10 is obtained. Note that the heat treatment step of Step 3-5 can be omitted.

FIG. 9 is a diagram for explaining a state in which the composite grinding wheel 10 is used by being attached to a double-sided surface grinding machine. In the figure, a pair of rotating shafts 42a, 42
b (hereinafter, simply referred to as a rotating shaft 42 when not particularly distinguished), and holders 44a, 44 for attaching the composite grindstone 10 are provided on the respective opposed front ends.
b (hereinafter simply referred to as a holder 44 unless otherwise specified). A pair of composite grindstones 10 are attached to the pair of holders 44a and 44b such that the grinding surfaces 10s face each other at a predetermined interval,
Each of the composite grinding wheels 10 is rotationally driven around its axis by a rotating shaft 42 perpendicular to the grinding surface 10s. Then, in a state where the composite grindstone 10 is rotated, the workpiece 46 such as a knife is passed between the grinding surfaces 10 s at a position lower than the axis of the rotating shaft 42, thereby causing the workpiece 46 to rotate. Both sides in the thickness direction are ground. The actual width of the ground surface in this case is (outer diameter-inner diameter)
/2=(355-250)/2=52.5 (mm).

In the composite grindstone 10 of this embodiment, the vitrified grindstone 14 is stirred in a state in which the fluid grindstone material 40 containing a surfactant in addition to the abrasive grains and the liquid resin is formed to form a large number of bubbles. By pouring around and curing, a porous resinoid grindstone 16 having a large number of pores 24 due to the bubbles is provided, so that the porosity is significantly higher than in the past, and the occurrence of clogging and welding is suppressed. The vitrified grindstone 14 effectively contributes to grinding over a long period of time, and excellent grinding performance can be obtained. The area ratio between the vitrified grindstone 14 and the resinoid grindstone 16 on the grinding surface 10 s is
The porosity and the like are set so that the chips are sufficiently contained in the pores 24 and grinding burns and welding do not pose a practical problem.

The vitrified grindstone 14 is reinforced by impregnating and hardening the liquid resin (epoxy resin 22) of the fluid grindstone material 40 into the pores of the vitrified grindstone 14, so that the vitrified grindstone 14 is welded or the like. 14 chipping (such as chipping) is effectively prevented, and the wear of the grinding wheel accompanying the grinding process is suppressed.
The grinding wheel life is improved. Thereby, the grinding performance of the composite grindstone 10 is improved in a well-balanced manner in combination with the porous resinoid grindstone 16. For example, even in grinding of difficult-to-cut materials such as a composite material of aluminum and SiC, grinding burn and welding of the grindstone are prevented. In addition to being suppressed, chipping of the vitrified grindstone 14 due to welding or the like is effectively prevented, and grinding performance and durability (grinding wheel life) sufficiently satisfactory in practical use can be obtained.

On the other hand, since the plurality of pores 24 of the resinoid grindstone 16 are independent of each other, there is no danger that the grinding fluid penetrates into the inside and deteriorates the resin binder as in the case where the pores communicate with each other. Since many pores 24 are substantially uniformly dispersed in the structure of the resinoid grindstone 16,
Substantially uniform grinding performance is maintained for a long time. Also,
Compared with a conventional porous resinoid grindstone that forms pores using a pore-forming material, there is no foreign matter derived from the pore-forming material, and therefore, there is no possibility that grinding performance is impaired due to the foreign matter.

In this embodiment, the flowable grindstone material 40 is used.
Is poured around the vitrified grindstone 14 to form the resinoid grindstone 16 and to fix the resinoid grindstone 16 at the same time, and the liquid resin (epoxy resin 22) of the flowable grindstone material 40 is impregnated into the pores of the vitrified grindstone 14 to reinforce it. Therefore, the number of steps is smaller than when the resinoid grindstone 16 is manufactured separately and fixed to the vitrified grindstone 14 with an adhesive or the like, or the vitrified grindstone 14 is impregnated with the liquid resin in another step. And production costs are reduced.

Further, since the flowable grindstone material 40 is poured in two steps, the pores of the vitrified grindstone 14 are sufficiently impregnated with a liquid resin (epoxy resin 22) to obtain desired strength and wear resistance. And the like are obtained, and the intrusion of bubbles into the boundary between the vitrified grinding wheel 14 and the resinoid grinding wheel 16 is also suppressed.

Incidentally, the composite grinding wheel 10 (product of the present invention)
(A) Alumina abrasive grains (WA) (# 220): 70.0% by weight; (b) Epoxy resin base material: 22.0% by weight, compared to the composite whetstone 10 (c) Epoxy resin hardener: A resinoid grindstone was manufactured using a fluid grindstone material consisting of 8.0% by weight, and only a comparative product 1 differing only in that it was fixed, and only a large number of vitrified grindstones 14 without a resinoid grindstone A comparative product 2 (grinding wheel shown in FIG. 6) was prepared in pairs, and the grinding performance was examined by performing grinding under the following grinding conditions. The results shown in Table 1 were obtained. The “grinding ratio” in Table 1 is the volume ratio of the amount of grinding of the workpiece to the amount of wear of the grindstone. FIG. 3B is a diagram showing the structure of the resinoid grindstone in the comparative product 1. (Grinding conditions) ・ Whetstone dimensions; φ355 × φ250 × 120 (mm) ・ Machine used: Double-sided surface grinding machine ・ Grinding method: Wet double-sided surface grinding ・ Wheel wheel peripheral speed: 1340 m / min ・ Material to be ground: MMC (Al 70% − (SiC 30%) ・ Size of material to be ground; Length 100 (mm) × Width 20 (mm) ・ Cut size; 0.7 (mm / pass)

[0042]

[Table 1]

As is clear from Table 1, the product of the present invention has a grinding ratio of about twice that of the comparative product 1 and has less wear.
There is no grinding burn on the surface state of the workpiece (material to be ground). The comparative product 2 has a grinding ratio as small as 以下 or less of the product of the present invention, causes grinding burns and welding, and also shows chipping due to welding and the like.

In the above example, the vitrified grindstone portion is constituted by a large number of independently constituted vitrified grindstones 14. For example, as shown in FIG. Notch 56
It is also possible to apply the present invention to a composite grindstone 60 in which a porous resinoid grindstone 58 is embedded in the groove 54 or the notch 56. In this case, the upper surface 52 corresponds to the ground surface, and the portions of the vitrified grindstone 50 and the resinoid grindstone 58 that are exposed on the upper surface 52 constitute a vitrified grindstone portion and a resinoid grindstone portion.

Although the embodiments of the present invention have been described in detail with reference to the drawings, these embodiments are merely examples, and can be applied to a compound grinding wheel used for grinding other than double-sided surface grinding. The present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a perspective view of a composite grinding wheel according to an embodiment of the present invention.

FIG. 2 is a plan view and a longitudinal sectional view of the composite grindstone of FIG. 1;

FIG. 3 is a diagram showing a structure of a porous resinoid grindstone in the composite grindstone of FIG. 1 in comparison with a normal resinoid grindstone.

FIG. 4 is a process chart showing a manufacturing process of the composite grindstone of FIG. 1;

FIG. 5 is a perspective view showing a vitrified grindstone manufactured in step 1 of FIG. 4;

FIG. 6 is a view showing a state in which a number of vitrified grindstones are fixed to a base in step 2 of FIG. 4;

FIG. 7 is a view for explaining a resinoid grinding stone manufacturing / fixing step of step 3 in FIG. 4;

FIG. 8 is a process chart specifically explaining step 3 of FIG. 4 in detail.

FIG. 9 is a view for explaining an example of a use form of the composite grindstone of FIG. 1;

FIG. 10 is a diagram illustrating another embodiment of the present invention.

[Explanation of symbols]

10, 60: composite whetstone 10s: ground surface 14, 50: vitrified whetstone (vitrified whetstone part) 16, 58: resinoid whetstone (resinoid whetstone part) 20: alumina abrasive grains (abrasive grains) 22: epoxy resin (liquid resin) 24 : Pores 40: Fluid whetstone material 46: Material to be ground 52: Upper surface (ground surface)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI B24D 3/32 B24D 3/32 7/14 7/14 (56) References JP-A-2-292178 (JP, A) JP-A-2-292178 JP-A-10-138148 (JP, A) JP-A-10-138149 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B24D 3/02 B24D 3/02 310 B24D 3/00 320 B24D 3/00 340 B24D 3/32 B24D 7/14

Claims (2)

(57) [Claims] 1. A method for manufacturing a composite grindstone in which a grinding surface for grinding a workpiece is constituted by a vitrified grindstone portion and a porous resinoid grindstone portion provided so as to fill around the vitrified grindstone portion. A vitrified grindstone manufacturing process for fabricating the vitrified grindstone part, and a fluid grindstone material containing abrasive particles, a liquid resin acting as a binder, and a surfactant are stirred to form a large number of air bubbles. By pouring around the vitrified grindstone portion and hardening, the porous resinoid grindstone portion having a large number of pores due to the bubbles is manufactured, and is simultaneously fixed integrally to the vitrified grindstone portion, and the fluidity poured into the vitrified grindstone portion. The liquid resin of the grinding wheel material is impregnated into the pores of the vitrified grinding wheel portion and hardened, thereby forming the vitrified grinding wheel. And a resinoid grindstone production and fixing step to reinforce the de grinding wheel portion, and the resinoid grindstone manufactured and fixed
The step is a step in which the fluid whetstone material in which a number of bubbles are created by stirring.
Into the vitrified grindstone portion to approximately the same height
The liquid is introduced into the pores from the side surface of the vitrified grinding wheel.
A first pouring step of impregnating the vitreous resin , and the liquid resin being substantially impregnated from a side surface of the vitrified grindstone portion.
While immersed, the vitrified whetstone part is buried to the upper surface.
Second pouring further pouring the fluid grindstone material as described above
And exposing the upper surface of the vitrified whetstone portion,
On the vitrified grinding wheel and the resinoid grinding wheel
Remove excess resinoid grinding stone so that surface is almost flush
A composite whetstone, comprising:
Construction method. 2. A grinding surface for grinding a material to be ground is a vitritor.
Fill around the fido whetstone and vitrified whetstone
With a porous resinoid grinding wheel
A method of manufacturing a composite whetstone, comprising: Vitrified grinding for manufacturing the vitrified grinding wheel
Stone making process, Abrasives, liquid resin acting as binder, and surface activity
Stir the fluidized grindstone material containing the agent to create numerous air bubbles
Flow around the vitrified whetstone Push in
By curing, it has many pores due to the bubbles
At the same time as manufacturing the porous resinoid grindstone part
In addition to being integrally fixed to the vitrified whetstone,
The liquid resin of the fluidized grindstone material that has been impregnated is subjected to vacuum defoaming treatment.
Forcibly impregnates the pores of the vitrified grinding wheel
The vitrified grindstone portion is cured by being
Manufacturing and fixing process of resinoid whetstone to reinforce Have
And a method for producing a composite whetstone.