JPH06312376A - Ultra-abrasive wheel embedded therein with striplike chips, for precise cutting - Google Patents

Abstract

PURPOSE:To enhance the efficiency of discharge of chips while maintaining a low chipping value by embedding strip-like chips having a wearing speed which is different from that of an abrasive layer continuously formed over the outer periphery of an ultra-abrasive wheel, in the outer surface of the abrasive layer in a staggering pattern. CONSTITUTION:An precisely cutting ultra-abrasive wheel comprises a ring-like mother abrasive layer composed of #600 diamond abrasive having a degree of concentration of 100 (25vol.%) and binder of CU80-Sn20(wt.%), and formed over the outer periphery of a disc-like substrate 1. Further, strip-like chips 3 are embedded in the front and rear surfaces of the mother abrasive layer 2. Further, the working hardness of the chips 3 is in a range of 50 to 90, or 110 to 150 with respect to the working hardness of the abrasive layer 2 which is set to 100. Accordingly, the abrasion progressing speed during use is retarded. Further, the chips 3, is formed of the same abrasive as that of the abrasive layer 3 with the use of Cu72-Cn18-Fe10 as a binder, are arranged at pitches of, for example, 150mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superabrasive wheel for precision cutting, which is used for cutting ceramics, ferrite, quartz, cemented carbide, hardened steel and the like.

[0002]

2. Description of the Related Art Conventionally, for cutting ceramics, ferrite, quartz, cemented carbide, hardened steel, etc., a metal base metal has been provided with an ultra-hard abrasive grain layer such as diamond or cubic boron nitride. Things are being used.

Particularly, as a superabrasive grain wheel for precision cutting of brittle materials and difficult-to-cut materials, it has a continuous abrasive grain layer on the outer peripheral edge of the substrate so that a good machined surface can be easily obtained with less chipping at the end of the machined surface. Wheels are used. However, in such a wheel, since the abrasive grain layer is continuous in a ring shape, the supply of the grinding fluid is insufficient, and the chips generated by the processing cannot be sufficiently discharged, which easily causes the clogging phenomenon.

On the other hand, as one that improves the machining efficiency by improving the discharge of chips, one that has slits in the abrasive grain layer,
A segment type abrasive grain layer, a corrugated side surface of the abrasive grain layer, and the like are in practical use. However, such a structure basically causes the abrasive grain layer to intermittently collide with the work material, resulting in large chipping, and cannot be used particularly for precision machining.

Further, Japanese Patent Publication No. 61-5854 discloses that
A wheel having a two-layer structure has been proposed in which a second abrasive grain layer made of a resin bond is provided on a side surface of a metal bond wheel, and finishing processing is also performed after rough cutting at the same time. However, in this wheel, there is a problem in that the resin bond abrasive grain layer wears quickly, and thus the processing accuracy is likely to vary, and because the wheel is a two-layer type, the wheel becomes thick and the machining cost increases.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above problems in a superabrasive grain wheel for precision cutting, and maintains the chipping amount at a low level and removes the chips generated by the supply and cutting of the grinding fluid. The purpose of the present invention is to obtain a superabrasive wheel for precision cutting, which has an excellent discharging effect.

[0007]

In order to achieve the above object, the present invention has at least an outer peripheral portion such as a wheel having a continuous abrasive grain layer on the outer peripheral edge of a substrate or a wheel in which the entire substrate is formed of an abrasive grain layer. In a superabrasive grain wheel for precision cutting having a continuous abrasive grain layer, a grain-shaped abrasive grain layer chip (hereinafter referred to as a grain-shaped chip) having a wear rate different from that of the abrasive grain layer on the front and back surfaces of the abrasive grain layer. .) Are buried in a zigzag pattern.

[0008] Here, by setting the thickness of the tumble-shaped chip in the range of 1/3 to 2/3 of the thickness of the abrasive grain layer,
It is possible to embed the abrasive grain layer without impairing its strength.

The difference in the wear rate can be obtained by varying at least one of the bond bond degree, the abrasive grain concentration degree, and the abrasive grain size.
When the working hardness of the central mother abrasive grain layer is set to 100, the working hardness of the tuna chips is 50 to 90, or 110 to 15
Within the range of 0, due to the difference in wear between the mother abrasive grain layer and the chip-shaped chips, it is possible to form an appropriate step having an excellent chip discharging effect and less chipping.

In the metal bond composition of the tuna-shaped chip, metal powder and abrasive grains, and if necessary, a filler are added, and the mixture is mixed and stirred by a wet or dry system, and then thinly spread on a mold, and heat and pressure are applied. , This is baked to be manufactured. At this time, since the main calcination is added later together with the mother abrasive grain layer, it is not necessary to obtain a sufficient density, and a density of about 90 to 95% is sufficient.

In the resin bond composition, resin bond powder and abrasive grains and, if necessary, a filler are added, an adhesive is added in a solvent, and the mixture is kneaded into a paste, spread into a sheet, and dried. To manufacture.

Using this tumble-shaped tip, the superabrasive grain wheel for precision cutting of the present invention is manufactured by the following method.

As shown in FIG. 4, the die used for sintering is composed of a middle die 5 sandwiching the substrate 1, an outer die 4, an upper die 6 and a lower die 7 for applying pressure to the abrasive grain layer. This up and down die 6,
The chip-shaped chips 3 are adhered to the inner surface of the device 7 using a heat-dissipating adhesive in a zigzag pattern at desired intervals. Next, the substrate is sandwiched by the middle mold 5, the lower press mold 7 and the outer mold 4 are assembled, and the middle mold 5
A bond between the mother abrasive grain layer and the mixed powder of superabrasive grains is filled in a gap between the outer die 4 and the outer die 4 (on the lower die 7). Next, the surface of the upper die 6 to which the tuna chips 3 are attached is turned down and sealed toward the filled mixed powder side. At this time, the vertical guide dies 6, 7 and the outer die 4 are provided with alignment guides 8 so that the shavings chips 3 adhered to the lower press die side 7 and the upper push die 6 have a predetermined zigzag shape. In this state, heat and pressure are applied to sinter.

In the case of metal bond, the sintering temperature is 500 ° C. or higher in order to sinter the metal powder such as Cu and Sn, and in the case of resin bond, the resin such as phenol is used as the bond. , Heating to 150 to 200 ° C. on a heating plate.

Furthermore, by polishing the surface of the abrasive grain layer of the sintered precision cutting superabrasive grain wheel, either the mother abrasive grain layer or the tumble-shaped chip is scraped off more, and the continuous abrasive grain layer is removed. A product with a minute and gentle step formed on the side surface of is completed.

[0016]

In the superabrasive grain wheel for precision cutting of the present invention, the mother abrasive grain layer and the chip-shaped chips are locally worn with use, and a minute step is formed at the boundary between the mother abrasive grain layer and the chip-shaped chips. Is formed. The chips generated during the cutting process due to the minute steps can be efficiently discharged to the outside. Further, the grinding liquid can be easily supplied from the side surface of the substrate to the grinding point through the step, and the occurrence of grinding burn is reduced.

[0017]

FIG. 1 is a partial plan view of a superabrasive grain wheel for precision cutting according to an embodiment of the present invention, FIG. 2 is a bottom view of the superabrasive grain wheel for precision cutting shown in FIG. 1, and FIG. Is a bottom view of a superabrasive wheel for precision cutting at 150 ^D × 1 ^T × 3
On the outer peripheral edge of the disk-shaped substrate 1 of ^X , a synthetic diamond abrasive grain of # 600 having a concentration of 100 (25% by volume) and Cu80-
A continuous ring-shaped mother abrasive grain layer 2 is formed using a binder of Sn20 (wt%), and the tumble-shaped chips 3 are embedded in the front and back surfaces of this mother abrasive grain layer 2.

The chip-shaped chip 3 has dimensions of 5 ^L x 3 ^W.
× 0.3 ^T , provided at a pitch of 15 mm, using the same abrasive grains as the mother abrasive grain layer 2 and using Cu72-S as a binder.
n18-Fe10 was used. As a result, as shown in FIG. 3, it is harder than the mother abrasive grain layer 2 (the working hardness of the abrasive grain layer is 1
In the case of 00, 130), the rate of progress of wear during use was slow.

A working test was actually carried out using this example product.

As a comparative example, a conventional superabrasive grain wheel for precision cutting, which does not have a scrap-shaped chip, was used. Comparative Example 1
As the binder, the same composition as the mother abrasive grain layer of Example 1 was used, and as the comparative example 2, the same composition as the pomegranate-shaped chip of Example 1 was used. The other conditions are the same as those in the example.

The processing conditions are as follows.

Work Material: Ferrite Wheel peripheral speed: 1600 m / min Depth of cut: 5 mm Feed rate: 0.6 m / min Cutting length: 50 mm x 200 cuts Total 10 m Grinding liquid: aqueous solution The results are shown in Table 1.

[0023]

[Table 1] In this way, in Example product 1 in which the working chips having the working hardness harder than the mother abrasive grain layer were arranged, the wear amount of the mother abrasive grain layer portion was larger than that of the mother chips and the boundary portion was 4 to 6 μm. There was a small step. As a result, the contact resistance to the work material on the side surface of the wheel was reduced, the power value was low, the sharpness was good, and the chipping was small.

As Test Example 2, a working test was carried out using Example 2 and Comparative Example 3 using a mother abrasive grain layer having a varying degree of concentration of abrasive grains and a tumble-shaped tip. Table 2 shows the wheel specifications of Example 2 and Comparative Example 3.

[0025]

[Table 2] The cutting conditions are as follows.

Work Material: Cemented Carbide Grinding Machine: Horizontal Axis Surface Grinder Wheel peripheral speed: 1600 m / min Depth of cut: 2 mm Feed rate: 0.5 m / min Cutting length: 100 mm x 100 cuts Total 10
m Grinding liquid: aqueous solution The results are shown in Table 3.

[0027]

[Table 3] Example 2 in which the degree of concentration of the scrap chips and the mother abrasive grain layer was changed
Had a difference in wear rate, and a minute step was generated. Comparative Example 3
Although the cutting load gradually increased due to the crushing of the abrasive grain layer and the clogging of the cutting chips, and finally the burning occurred, the wheel of the present invention is well supplied with the grinding fluid from the minute step, and the crushing Prevents jams, no burning occurred, and good sharpness was maintained.

[0028]

According to the present invention, the following effects can be obtained.

(1) The discharge of chips is improved, the clogging phenomenon can be reduced, and highly efficient cutting is possible.

(2) Since the step formed on the side surface of the abrasive grain layer is gentle, it does not impair the processing quality of the workpiece.

(3) Since the contact area of the side surface with the workpiece is reduced, the cutting resistance is reduced.

(4) By using a composition having a high wear resistance for the Tanzaku chip, it is possible to prevent the occurrence of corner sag at the bottom of the groove when used for grooving.

(5) Since the grinding liquid is more easily supplied to the grinding point than the clearance on the side surface, it is effective in preventing burning.

[Brief description of drawings]

FIG. 1 is a partial plan view of a superabrasive wheel for precision cutting which is an embodiment of the present invention.

FIG. 2 is a bottom view of the superabrasive wheel for precision cutting shown in FIG.

FIG. 3 is a bottom view showing a situation after using the superabrasive wheel for precision cutting shown in FIG.

FIG. 4 is a cross-sectional view showing a method of manufacturing a superabrasive wheel for precision cutting of the present invention.

[Explanation of symbols]

 1 Substrate 2 Mother Abrasive Grain Layer 3 Tandem Chip 4 Outer Mold 5 Middle Mold 6 Upper Mold 7 Lower Mold

Claims (2)

[Claims] 1. A superabrasive grain wheel for precision cutting having a continuous abrasive grain layer on at least an outer peripheral portion thereof, and a tumble-shaped chip having a wear rate different from that of the abrasive grain layer on the front and back surfaces of the abrasive grain layer. A superabrasive wheel for precision cutting characterized by being buried in a zigzag pattern. 2. When the working hardness of the abrasive grain layer is 100, the working hardness of the tumble-shaped superabrasive grain layer chip is 50 to 50.
90 or 110-150, The superabrasive grain wheel for precision cutting according to claim 1, characterized in that.