JP3502971B2 - Cutting wheel - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cutting wheel,
More specifically, the present invention relates to a grinding wheel that has irregularities on its side surfaces and is free from clogging and has a long life.

[0002]

2. Description of the Related Art Conventional grinding wheels such as cutting wheels and flat wheels
It is manufactured by compression-molding abrasive grains made of silicon carbide, gold sand, or the like together with a binder into a disk shape, and then heat-treating the binder. Abrasive grains of various particle sizes are appropriately blended according to the application of the grinding wheel, and a binder made of a liquid or powdery phenolic resin or the like is blended therein. A disk-shaped lower mold is fitted on the bottom of the cylinder, abrasive grains are evenly placed on it, and the disk-shaped upper mold is fitted, and the disk is made uniform by pressing with a hydraulic press or the like. It is fired after being shaped into a shape.
At the time of this molding, a reinforcing cloth made of glass fiber or the like is sandwiched between both sides of the disk or the intermediate layer and pressed.

The above conventional grinding wheel often causes clogging during cutting or cutting of metal or the like, resulting in poor sharpness.
Further, there is a problem that the friction stone heats the grindstone and the cut object to a high temperature, which shortens the life of the grindstone. Especially aluminum,
When grinding a soft metal such as brass, it is severely clogged and often needs to be re-dressed. When cutting stainless steel, the cutting material may become hot and discolor.

Therefore, Japanese Patent Application Laid-Open No. Sho 49-132688 discloses a relatively hard fan-shaped grinding member having a small pore volume (porosity).
It has been proposed to prevent grinding of the grinding wheel by increasing the grinding efficiency by alternately arranging relatively soft fan-shaped grinding members having a large pore volume (porosity) to form a grinding wheel. This grinding wheel in which a relatively hard fan-shaped grinding member having a small porosity and a relatively soft fan-shaped grinding member having a large porosity are alternately arranged, the soft and hard fan-shaped grinding members are separately provided with abrasive grains. After being molded and fired to make segments, these are alternately arranged and assembled into a disc shape by bonding or the like, the manufacturing process is extremely complicated, and the adhesive strength of the fan-shaped segments is It was weak and could be chipped or cracked from the bonded portion of the grinding wheel segment during the grinding operation.

Therefore, the inventor of the present invention has disclosed the Japanese Patent Publication No. 3-67834.
When molding a grinding wheel with a die, as shown in No. 5, after forming radial fan-shaped irregularities on the upper surface of the abrasive grain layer before compression molding, the entire disk is uniformly shaped with a disk-shaped upper mold having a flat lower surface. When pressed to a different thickness, in the state where the uneven shape is formed, the convex portion of the abrasive grain layer has a large thickness of the abrasive grain layer and the concave portion has a small thickness.
The convex portion of the abrasive grain layer has a high compressibility and a high abrasive grain density, and the concave portion of the abrasive grain layer has a low compressibility and a low abrasive grain density, which means that the abrasive grain density is high. It was shown that a grinding wheel with alternating fan-shaped parts and small fan-shaped parts could be molded simultaneously.

Further, the present inventor, in Japanese Patent Application No. 7-119390, places a lower mold having an uneven upper surface in a cylindrical mold when manufacturing a disk-shaped cutting wheel, and relatively puts it on it. Evenly mix the compounded abrasive grains with low fluidity, press a pressing die having an uneven shape on the lower surface of the abrasive grain layer, and press the pressing die as it is as an upper die for pressing. Grains do not move horizontally but are compressed vertically as they are.Therefore, the thinly molded part of the grinding wheel, where the thickness is thin, has a high compression rate of abrasive particles and a high abrasive grain density. The thick part of the has a low compressibility of the abrasive grains and a low abrasive grain density, and it is possible to clearly divide the high abrasive grain density part and the high abrasive grain density part, and the cutting produced in that way Grinding wheels are extremely unlikely to cause clogging,
It has been disclosed that the cutting speed is excellent.

[0007]

The conventional cutting wheel is apt to cause clogging when cutting soft metals such as brass and aluminum, and has a slow cutting speed when cutting stainless steel and the like. If too much load is applied during cutting in order to increase the cutting speed, the grinding wheel will be damaged and wear due to frictional heat will be severe, which is very dangerous for the operator. Further, when an attempt is made to form a portion having a large abrasive grain density and a portion having a small abrasive grain density on the cutting wheel by the method disclosed in Japanese Patent Application No. 7-119390, a disc-shaped cutting wheel and a portion having a small abrasive grain density are used. The difference in the thickness of the part with a high grain density inevitably has to be made quite large, and the cutting wheel may be distorted due to the difference in the partial thickness of the formed cutting wheel and the difference in the abrasive grain density. There is. Therefore, the present invention is to provide a cutting wheel with less distortion, which is a cutting wheel with excellent sharpness and long life, which efficiently cuts by contacting the circumferential surface of a rotating disk wheel with a workpiece. To aim.

[0008]

[Means for Solving the Problems] In order to achieve the above object,
As a result of repeated studies by the present inventor, the cutting efficiency of the cutting wheel is increased, and in order to prolong the life, a partial abrasive grain density difference of the cutting wheel is not necessarily required, and the cutting wheel as a whole Even if the abrasive grain density is substantially uniform, a slight difference in the thickness of the cutting wheel is provided along the circumference of the cutting wheel during cutting, and when a slightly thicker portion and a slightly thicker portion are formed, this results in By alternating contact with the material to be cut, just the "clam" of the saw
It has an effect like the above, is effective in discharging cutting dust and falling abrasive grains, and cooling the cutting wheel, and as a result has excellent cutting efficiency and excellent cutting efficiency compared to the conventional cutting wheel of uniform thickness.
There is no clogging, the cutting speed is greatly improved, the wear of the cutting wheel is small and the life is greatly extended, and even if there is a slight difference in the thickness of the cutting wheel, the whole is almost uniform. As far as the abrasive grain density is concerned, rather than the conventional flat-plate cutting grinding wheel, distortion of the cutting grinding wheel does not occur, and it is found that a cutting grinding wheel having no run-out at the time of rotation is obtained and the present invention is completed. It was.

That is, according to the present invention, an abrasive grain mixture prepared by mixing abrasive grains with a binder or the like is compression-molded into a disc shape and fired, and the entire disc is molded by the abrasive grain mixture and fired. In the disk-shaped cutting wheel that is configured, the unevenness is provided on one side or both sides of the cutting wheel, and by compressing it from both sides using a highly fluid abrasive compound as the abrasive compound. By forming into a disc shape, the density of the abrasive grains inside the cutting wheel is made substantially uniform, and during the cutting operation, the abrasive grains that have fallen off the corners of the convex portions of the irregularities renew the surface of the wheel. A cutting wheel used for cutting metal is characterized in that the cutting speed of the metal material is kept high.

[0010]

The contents of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a plan view of a cutting grinding wheel of an example of the grinding wheel of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a sectional view taken along the line AA of the same circle.
FIG. 4 is a sectional view taken along the arc BB. Reference numeral 1 denotes a cutting wheel, which is provided on its side surface 2 with elongated fan-shaped convex portions 3 and concave portions 4 extending radially. It is preferable that the convex portion 3 and the concave portion 4 are provided on both sides of the cutting wheel 1 in a plane-symmetrical manner, but it is not always necessary to have a symmetrical shape, and unevenness may be provided on only one side of the cutting wheel 1 or the cutting wheel 1 may be cut. The concavo-convex shapes on both sides of the grinding wheel 1 may have different shapes and different arrangements.

The shapes and arrangements of the concave portions 4 and the convex portions 3 on the side surface 2 of the cutting wheel 1 are not limited to those shown in FIG. 1, of course, and various shapes can be arranged. The condition necessary for the arrangement is that the convex portions 3 and the concave portions 4 are alternately arranged at an appropriate ratio on all concentric circles within the range used for cutting among the concentric circles centering on the rotation axis of the cutting wheel 1 Need to On a particular concentric circle, it is not preferable that only the convex portion 3 or only the concave portion 4 is arranged over the entire circumference of the concentric circle. What is more, when the cutting wheel 1 is worn to the concentric circles, the cutting wheel 1 is cut only by the convex portions 3 or the concave portions 4 and has a constant width.
This is because the cutting is performed along the peripheral edge of the cutting wheel, and the state is the same as the cutting by the conventional conventional cutting wheel 1.

Other examples of the shapes and arrangements of the concave portions 4 and the convex portions 3 are shown in FIGS. 5 and 6, for example. In FIG. 5, a large number of protrusions 3 are present in an island shape in the recesses 4 on the side surface 2. In FIG. 5, the concave portion 4 becomes the convex portion 3, the convex portion 3 becomes the concave portion 4, and the convex portion 3 and the concave portion 4
May be the reverse of the arrangement shown in FIG. FIG. 6 shows a radial checkered concave portion 4 in each portion divided by concentric circles and radially extending lines.
And the convex portions 3 are arranged (FIG. 6 shows only the concave portions 4 and a part of the convex portions 3).

The wave 16 having the uneven cross-sectional shape on the side surface 9 of the cutting wheel 5 is not limited to the rectangular wave shape shown in FIG. 4, but the sawtooth wave shown in FIG. 7, the triangular wave shape shown in FIG. Any shape such as the trapezoidal wave shape shown in Fig. 10 and the substantially sine wave shape shown in Fig. 10 is possible.

The concave portions 4 and the convex portions 3 are radially arranged as shown in FIG.
When providing, the number of waves 16 in the cross section of the concentric circles is not particularly limited, but depending on the diameter of the grinding wheel and the purpose of use thereof, a wave number of 3 to 200 is used, and more preferably 10 to 100. The wave number is used. For example, diameter 100mm
For the cutting wheel 1 of No. 1, a wave number of 15 to 50 is preferably used. The thickness of the cutting grinding wheel 1 at the convex portion 3 and the concave portion 4 is not particularly limited, but for example, when unevenness is provided symmetrically on both sides of the grinding wheel, the thickness of the grinding wheel at the concave portion 4 (the maximum of the grinding wheel Thickness D is 1.0 to 4.0 mm, the thickness d of the grinding wheel in the recess 8 is 0.5 to 3.6 mm, and the ratio d / D is 0.5.
It can be set to 0.95, more preferably 0.7 to 0.9. The wave height h of the wave 16 is 0.1 to 1 mm, preferably 0.1 to 0.5 mm, more preferably 0.1 to 0.25 mm.
And, 2 to 25% of the thickness D of the convex portion 3 of the cutting wheel 1 is preferable, 3 to 15% is more preferable, and 5 to 10% is further preferable. When the wave height h is less than 2% of D, the effects of preventing clogging and improving the cutting speed become small. Wave height h is D
If it is larger than 25%, it becomes difficult to form the concave and convex portions 3 so that the abrasive grain densities of the concave portion and the convex portion 3 become substantially constant during press molding of the grinding wheel, and distortion occurs in the cutting wheel 1 formed and fired. It becomes easier and the strength of the entire grinding wheel is reduced. The smaller the wave height h, the easier the shaping so that the abrasive grain density becomes substantially constant. The area ratio between the concave portions 4 and the convex portions 3 is not particularly limited, but for example, 0.2 to 1.0 is selected, and 0.4 to 0.7 is preferably used.

The wave height h does not have to be constant for all waves, and the wave height h can be changed depending on the wave. Wave height h
Large, medium, and small waves of can be repeatedly arranged in that order and cyclically arranged.

In order to manufacture the grinding wheel of the present invention, for example, in the case of the cutting grinding wheel 1 shown in FIGS. 1 to 4, as shown in FIG. 11, a mold comprising a cylinder 5, a lower mold 6 and an upper mold 7. 8 is used. The upper mold 7 and the lower mold 6 each have a central hole 10 through which a pin 9 is inserted, and a corrugation for forming a rectangular wave in a radial pattern on the lower surface of the upper mold 7 and the upper surface of the lower mold 6. Have 11.

The lower die 6 is fitted to the bottom of the cylinder 5 of the die 8 and a thin abrasive compound 12 to be described later is put on the lower die 6 and the whole is leveled to a constant depth. By placing a reinforcing cloth 13 made of glass fiber or the like on it, further putting the abrasive grain mixture 12 at a constant depth and pressing the upper part with the upper mold 7, and slightly rotating or vibrating the upper mold 7. Then, the density of the abrasive grain mixture 12 is made substantially uniform, and pressure is applied by a hydraulic press device. If necessary, another reinforcing cloth 13 made of glass fiber or the like may be sandwiched between the abrasive grain layers and pressed. The reinforcing cloth 13 is an abrasive grain compound 12
You may arrange on both lower surfaces.

As the abrasive grains used for producing the grinding wheel of the present invention, known abrasive grains for grinding wheels such as silicon carbide, alumina, zirconia, and hard sand can be used. It is also possible to partially mix and use diamond abrasive grains. A liquid phenol resin such as a resol type resin or a benzylic ether type resin and a powdery phenol resin are mixed with the abrasive grains as a binder to form an abrasive grain mixture 12. The mixing ratio is 15 to 35 parts by weight with respect to 100 parts by weight of abrasive grains.
-25 parts by weight is more preferable. The fluidity of the abrasive compound can be appropriately adjusted by adjusting the ratio of the liquid phenol resin and the powdery phenol resin and the compounding amount thereof. In order to produce a grinding wheel by the method of the present invention, it is necessary to adjust the fluidity of the abrasive composition to a suitable fluidity that allows it to flow freely. In a state where the abrasive composition 12 has low fluidity, when the abrasive layer is pressed by the upper die 7 having the corrugation 11 on the lower surface, the abrasive grains 3 in the portion corresponding to the lower part of the convex portion of the corrugation 11 move horizontally. It does not move easily, and the abrasive grain density of that portion becomes large, the abrasive grain density of the recessed portion 4 of the formed cutting wheel 1 becomes considerably higher than the abrasive grain density of the convex portion 3, and the entire cutting wheel 1 is It becomes impossible to keep the density of the abrasive grains substantially uniform. If the fluidity is poor, the press pressure is not evenly transmitted to the inside of the grinding wheel, and it becomes difficult to press uniformly in the direction perpendicular to the surface, which causes distortion after molding and firing.

The abrasive composition 12 may further contain an organic solvent or other liquid fluidity modifier. Further, additives such as powder fillers such as cryolite, calcium carbonate and white carbon, coloring agents and the like to be added to the abrasive grains during the production of a usual grinding wheel can be appropriately blended.

The abrasive composition 12 is pressed by the mold 8.
The pressure is not particularly limited, but usually 100 to 150 kgf / cm 2
Is used. Pressing temperature is 80 ~ 100 ℃
The loess temperature is used.

The disc-shaped abrasive grain compact is fired at 170 to 180 ° C. for about 24 hours. In the first 14 hours, the temperature is gradually raised from room temperature to around 170 ° C., and after that, the temperature is maintained at 170 to 180 ° C. for about 10 hours and then gradually cooled.

When a plurality of press-molded products of the grinding wheel of the present invention are fired and laminated at the same time, the press-molded product and the thickness 1 to 2 are formed so that the grinding wheel is not distorted during firing.
If thin iron plates of mm are alternately stacked and laminated, and 50 to 100 press-molded products are laminated and heated and baked while applying a load to the whole, the grinding wheel can be baked without being distorted during the baking. .

Next, an example of a method for manufacturing a grinding wheel by the method of the present invention will be described in more detail. 100 parts by weight of 60-mesh green silicon carbide powder, 18 parts by weight of liquid phenol resin, 650 parts by weight of cryolite powder filler, and a small amount of a coloring agent are mixed to form an abrasive grain mixture A. On the other hand, 100 parts by weight of 60-mesh green silicon carbide powder, liquid phenol resin 3
Parts by weight, powdered phenolic resin 20 parts by weight, cryolite powder 5
By mixing a part by weight and a small amount of a coloring agent, an abrasive grain mixture B is obtained. The abrasive grain formulations A and B are used by appropriately mixing them. Abrasive blends A and B were mixed in a mixing ratio of 3: 7 to 2: 8 and preheated to about 70 ° C.
As a lower abrasive layer 14a, it is evenly spread to a thickness of about 2 mm on the lower mold 6 in the mold 8 shown in FIG.
A reinforcing cloth 13 made of glass fiber impregnated with the phenol resin solution is laid on the surface. Further, an abrasive grain composition having the same composition as that of the lower abrasive grain layer 14a is further formed as an upper abrasive grain layer 14b so as to have a uniform thickness and be filled to a thickness of 2 mm. Finally, the metal reinforcing ring 15 is placed on top of the central portion of the abrasive grain layer 14. The abrasive grain layer 14 is covered with an upper die 7 having a rectangular wave-like corrugation 11 on the lower surface thereof, the irregularities of which extend radially, and is pressed to 80 kgf / cm ² with a 100 t hydraulic press to form the shape shown in FIGS. Then, a disk-shaped press-molded product having a diameter of 105 mm was obtained. The press temperature is 90 ° C. Fifty sheets of this press-molded product were alternately laminated with iron plates of 0.7 mm pressure each and placed in a firing furnace, and the temperature was raised to a predetermined temperature in 14 hours, and then 10
After keeping that temperature for a while, let it cool. The cutting wheel 1 thus obtained had no distortion at all, and a completely flat cutting wheel 1 was obtained.

Using this cutting wheel 1 an iron plate, a brass plate,
When cutting the surface of the aluminum plate, there is no clogging of the grinding wheel at all, it is possible to cut at a speed several times faster than the conventional normal cutting grinding wheel, and the life of the grinding wheel is long,
During use, there is no cracking or chipping of the grinding wheel, and it is possible to work extremely safely.

EXAMPLE A compounding ratio of the abrasive composition A and B of the upper and lower abrasive layers on the lower mold 6 having a diameter of 105 mm and a rectangular wave pattern 11 on the upper surface by the above method. 3:
7, the upper die 7 having a rectangular wave pattern 11 in a radial shape is pressed (FIG. 11) and fired, the number of the convex portions 3 is 18, the wave height h is 0.15 mm, and the thickness of the convex portions 3 is 2.0 mm. A cutting wheel 1 having a recess 4 having a thickness of 1.7 mm was produced. The cutting wheel 1 was used to cut and test a workpiece made of a steel rod (SS11) having a diameter of 16 mm at a load of 3000 and 4300 rpm and 3 kgf. The test results are shown in Table 1. The cutting speed is shown as a comparative value, where the conventional cutting grinding wheel manufactured in exactly the same manner using the upper die 7 and the lower die 6 having no corrugation is used as a comparative example, and the cutting speed of the comparative example is 1.

[Table 1]

[0026]

According to the grinding wheel of the present invention, the surface of the grinding wheel has irregularities, and the abrasive grain densities inside the concave portions 4 and the convex portions 3 are substantially equal to each other, so that the entire cutting wheel 1 has a uniform flat plate. Shaped as a wheel-shaped cutting wheel. When this grinding wheel is rotated to cut metal or the like, the cutting speed is surprisingly improved as compared with the case of cutting with a conventional normal cutting grinding wheel. This is because the abrasive grains fall off from the corners of the convex portion 3 of the grinding wheel, and this enters between the concave portion 4 next to it and the metal surface being cut, and at the same time the metal is cut,
The surface of the grindstone is renewed to eliminate the fine metal particles that are likely to be clogged in the gap between the abrasive grains, and the dropped abrasive grains and the cut metal powder rotate from between the recess 4 of the cutting wheel 1 and the cutting metal. It is presumed that this is because the cutting wheel 1 is quickly discharged to the outside by the centrifugal force.

The corrugations on the surface of the cutting wheel 1 of the present invention cool the wheel and the cutting metal by interrupting the sliding between the wheel and the metal during cutting while the wheel is rotating, The life of the grinding wheel can be greatly extended.

The cutting wheel 5 of the present invention can also be applied to a diamond cutting wheel using diamond abrasive grains. In that case, expensive diamond abrasive grains can be mixed with normal abrasive grains and placed only on the peripheral portion of the grinding wheel.

[0029]

According to the grinding wheel of the present invention, the cutting speed is remarkably improved as compared with the conventional normal cutting grinding wheel, and no clogging of the grinding wheel occurs even when cutting a soft metal. The life of the grinding wheel is greatly extended, a high cutting speed can be obtained even if the number of rotations of the grinding wheel is reduced, and there is no risk of damage to the grinding wheel during cutting. Carbide special steel could hardly be cut by the conventional cutting wheel, but it can be easily cut by the cutting wheel of the present invention. Furthermore, when cutting a metal material with a conventional ordinary cutting wheel, a "cutting flash" is always generated at the final cutting portion of the material, and this flash needs to be ground and removed by a rotary grinding wheel or the like. When cutting with the cutting wheel 1 of the present invention, no cutting flash is generated in the final cutting portion,
There is no need to grind away burrs.

[Brief description of drawings]

FIG. 1 is a plan view of an example of a grinding wheel of the present invention.

FIG. 2 is a front view of an example of the grinding wheel of the present invention.

FIG. 3 is a sectional view taken along line AA of an example of the grinding wheel of the present invention.

FIG. 4 is a cross-sectional view taken along an arc BB of an example of the grinding wheel of the present invention.

FIG. 5 is a plan view of an example of the grinding wheel of the present invention.

FIG. 6 is a plan view of an example of the grinding wheel of the present invention.

FIG. 7 is a plan view of an example of the grinding wheel of the present invention.

FIG. 8 is a plan view of an example of the grinding wheel of the present invention.

FIG. 9 is a plan view of an example of the grinding wheel of the present invention.

FIG. 10 is a plan view of an example of the grinding wheel of the present invention.

FIG. 11 is a cross-sectional view illustrating the method for manufacturing the grinding wheel of the present invention.

[Explanation of symbols]

1 cutting wheel 2 sides 3 convex 4 recess 5 cylinders 6 Lower mold 7 Upper mold 8 mold 9 pin 10 central hole 11 wavy 12 Abrasive compound 13 Reinforcement cloth 14 Abrasive layer 15 Metal reinforcement ring 16 waves

   ─────────────────────────────────────────────────── ─── Continued front page       (56) Reference JP-A-3-228579 (JP, A)                 JP 63-169269 (JP, A)                 JP-A-6-190726 (JP, A)                 JP-A-6-79631 (JP, A)                 JP-A-8-290362 (JP, A)                 JP-A-63-300872 (JP, A)

Claims (5)

(57) [Claims] 1. An abrasive grain composition prepared by mixing abrasive grains with a binder and the like is compression-molded into a disc shape and fired, and the entire disc is formed by molding and firing the abrasive grain mixture. In a disc-shaped cutting wheel that consists of the above-mentioned cutting wheel, unevenness is provided on one side or both sides of the wheel, and a highly fluid abrasive grain mixture is used as the abrasive grain mixture to compress it from both sides to form a disc shape. By forming into a substantially uniform abrasive grain density inside the cutting wheel, the abrasive grains that have fallen off the corners of the convex portions of the unevenness during the cutting operation renew the surface of the wheel, and A cutting wheel for cutting metal, characterized in that the cutting speed of the material is kept high. 2. A concave portion in an arcuate cross section along each concentric circle within the range used for cutting the cutting wheel among the concentric circles having the rotation axis of the cutting wheel as the center. The cutting wheel according to claim 1, wherein the convex portions are arranged alternately. 3. The concavo-convex portion is composed of a concave portion and a convex portion that extend in a substantially radial direction from a central portion of the cutting grinding wheel toward an outer peripheral portion, and in a cross section along a concentric circle concentric with the center of the cutting grinding wheel. The cutting wheel according to claim 1, wherein the surface of the cutting wheel has a corrugated shape such as a rectangular wave shape, a sawtooth wave shape, a triangular wave shape, a trapezoidal wave shape, or a substantially sine wave shape. 4. The wave height of the corrugation is 0.1 mm or more and the cutoff
It is 2 to 25% of the maximum thickness of the grinding wheel.
Grinding wheel described. 5. An abrasive grain composition prepared by compounding abrasive grains with a binder and the like.
When compressing and molding an object into a disk shape, place it on the center of the abrasive grain layer.
The compression molding according to claim 1, wherein a metal reinforcing ring is arranged.
Cutting wheel.