JP2972049B2 - Super-abrasive wheel for precision cutting with embedded tangled chips - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precision cutting superabrasive wheel 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, crystal, cemented carbide, hardened steel, etc., a super hard abrasive layer such as diamond or cubic boron nitride is provided on the outer periphery of a metal base metal. Things are used.

[0003] Particularly, a superabrasive grain wheel for precision cutting of a brittle material or a difficult-to-cut material has a continuous abrasive grain layer on the outer peripheral edge of the substrate so as to easily obtain a good machined surface with little chipping at the machined end. Wheels are used. However, in such a wheel, since the abrasive 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, so that a clogging phenomenon is easily caused.

[0004] On the other hand, as an improved cutting efficiency by improving the discharge of cutting chips, abrasive grains with slits,
Those having a segment type abrasive grain layer and those having a corrugated shape on the side face of the abrasive grain layer have been put to practical use. However, such a structure basically causes the abrasive layer to intermittently collide with the work material, resulting in increased chipping, and cannot be used particularly for precision machining.

Further, Japanese Patent Publication No. 61-5854 discloses that
There has been proposed a wheel having a two-layer structure in which a second abrasive layer made of a resin bond is provided on a side surface of a metal bond wheel, and finishing is performed simultaneously after rough cutting. However, in this wheel, there is a problem that machining accuracy is likely to be degraded due to rapid wear of the resin bond abrasive grain layer, and since the wheel is of a two-layer type, the wheel becomes thick and a machining allowance is increased.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in a superabrasive grain wheel for precision cutting, and maintains a low amount of chipping while supplying a grinding fluid and cutting chips generated by cutting. An object of the present invention is to obtain a superabrasive wheel for precision cutting with excellent discharge effect.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object , the present invention provides at least an outer peripheral portion such as a wheel having a continuous abrasive layer on the outer peripheral edge of a substrate or a wheel having the entire substrate formed of an abrasive layer. in the superabrasive wheel for precision cutting with abrasive layer contiguous said on both side surfaces of the abrasive grain layer, wear rate different wear rate of the short Jotogi grain layer chips of the same abrasive particle layer (hereinafter short-length Chip)) or the same abrasive layer
The short-length tip of the working hardness different working hardness you buried placed in a staggered manner.

[0008] Here, by setting the thickness of the tangle-like tip to be in the range of 1/3 to 2/3 of the width of the abrasive layer, it is possible to bury the chips without impairing the strength of the abrasive layer. Become.

The difference in wear rate can be obtained by changing at least one of the degree of bond bonding, the degree of concentration of abrasive grains, or the grain size of abrasive grains.
Assuming that the working hardness of the central mother abrasive layer is 100, the working hardness of the tangled tip is 50 to 90, or 110 to 15
If it is in the range of 0, an appropriate step with excellent chip discharge effect and less occurrence of chipping can be formed due to a difference in abrasion between the mother abrasive layer and the tangled chip.

[0010] In the metal bond composition, metal chips and abrasive grains, and fillers as necessary, are mixed and stirred in a wet or dry system, and the chips are spread thinly in a mold, and heat and pressure are applied thereto. It is manufactured by firing. At this time, since the final firing is added together with the mother abrasive layer, it is not necessary to obtain a sufficient density, and a density of about 90 to 95% may be sufficient.

In the resin bond composition, a resin bond powder and abrasive grains and, if necessary, a filler are added, a pressure-sensitive adhesive is added in a solvent, and the mixture is kneaded into a paste, stretched into a sheet, and dried. Manufacturing.

A superabrasive wheel for precision cutting according to the present invention is manufactured by the following method using the tangled chips.

As shown in FIG. 4, the mold used for sintering is composed of a middle mold 5, sandwiching the substrate 1, an outer mold 4, an upper mold 6 for applying pressure to the abrasive layer, and a lower mold 7. This upper and lower pressing mold 6,
The chip 3 is bonded to the inner surface 7 in a staggered manner at a desired interval using a heat-scattering adhesive. 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 is formed.
The mixed powder of the bond of the mother abrasive layer and the superabrasives is filled into the gap between the outer mold 4 and the lower mold 7 (on the lower pressing mold 7). Next, the surface of the upper pressing die 6 to which the tangled chips 3 are attached is faced down and sealed toward the filled powder mixture. At this time, the positioning guides 8 are provided on the upper and lower pressing dies 6, 7 and the outer die 4 so that the tangled chips 3 adhered to the lower pressing die 7 and the upper pressing die 6 have a predetermined staggered shape. In this state, sintering is performed by applying heat and pressure.

In the case of a metal bond, the sintering is performed at a high temperature of 500 ° C. or more in order to sinter a metal powder such as Cu or Sn, and in the case of a resin bond, a resin such as phenol is used as a bond. And heating at 150 to 200 ° C. on a hot platen.

Further, by polishing the surface of the abrasive layer of the sintered super-abrasive grain wheel for precision cutting, more of either the mother abrasive layer or the chip-like chips is scraped off, and the continuous abrasive layer is formed. A product in which a small and gentle step is formed on the side surface of is completed.

[0016]

In the super-abrasive grain wheel for precision cutting according to the present invention, the master abrasive layer and the tangle-like chips are locally worn with use, and a minute step is formed at the boundary between the mother abrasive layer and the tangle-like chips. Is formed. Chips generated during the cutting process due to the minute steps can be efficiently discharged to the outside. Further, the grinding fluid 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 super-abrasive grain wheel for precision cutting according to one embodiment of the present invention, FIG. 2 is a bottom view of the super-abrasive grain wheel for precision cutting shown in FIG. 1, and FIG. The bottom view of the 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 of $ 600 with a concentration of 100 (25% by volume) and Cu80-
A continuous ring-shaped mother abrasive layer 2 using a binder of Sn20 (% by weight) is formed, and a chip-shaped chip 3 is buried on the front and back surfaces of the mother abrasive layer 2.

The tangy chip 3 has a size of 5 ^L × 3 ^W
× 0.3 ^T , provided at a pitch of 15 mm, using the same abrasive grains as the mother abrasive 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 layer 2 (the working hardness of the abrasive layer is 1).
In the case of 130), the wear progress rate during use was low.

A processing test was actually performed using the product of this example.

As a comparative example, a conventional superabrasive grain wheel for precision cutting without a tangle-like tip was used. Comparative Example 1
As a binder, a binder having the same composition as that of the mother abrasive layer of Example 1 was used, and as Comparative Example 2, a binder having the same composition as the tangle-like chips of Example 1 was used. Other conditions are the same as those of the embodiment.

The processing conditions are as follows.

Work material: ferrite Wheel peripheral speed: 1600 m / min Cutting depth: 5 mm Feeding speed: 0.6 m / min Cutting length: 50 mm × 200 cuts Total 10 m Grinding fluid: aqueous solution The results are shown in Table 1.

[0023]

[Table 1] As described above, in the example product 1 in which the working chips are arranged with the peg-shaped tips harder than the base abrasive layer, the abrasion amount of the base abrasive layer portion is larger than that of the pricked chips, and the boundary portion is 4 to 6 μm. Small step was generated. As a result, the contact resistance of the wheel side surface to the work material was reduced, the power value was low, the sharpness was good, and the chipping was small.

As Test Example 2, a working test was conducted using Example 2 and Comparative Example 3 using a mother abrasive layer having a different degree of concentration of abrasive grains and a chip-shaped tip. Table 2 shows the wheel data of Example 2 and Comparative Example 3.

[0025]

[Table 2] The cutting conditions are as follows.

Work material: carbide alloy Grinding machine: horizontal axis surface grinder Wheel peripheral speed: 1600 m / min Depth of cut: 2 mm Feeding speed: 0.5 m / min Cutting length: 100 mm × 100 cuts Total 10
m Grinding fluid: aqueous solution The results are shown in Table 3.

[0027]

[Table 3] Example 2 in which the degree of concentration of the tangled tip and the mother abrasive layer was changed
In the test, there was a difference in abrasion speed, and a minute step was generated. Comparative Example 3
Although the cutting load gradually increased due to the grinding of the abrasive layer and the clogging of the chips, burning eventually occurred.However, the wheel of the present invention has a good supply of grinding fluid from a minute step, Prevention of clogging, no scorching occurred, and good sharpness was maintained.

[0028]

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

(1) The discharge of chips was improved, the clogging phenomenon was reduced, and high-efficiency cutting became possible.

(2) Since the step formed on the side surface of the abrasive grain layer is gentle, the processing quality of the processed product is not impaired.

(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, it is possible to prevent occurrence of corner droop at the groove bottom when used for grooving.

(5) The grinding fluid is easily supplied to the grinding point from the clearance on the side surface, which is effective in preventing burning.

[Brief description of the drawings]

FIG. 1 is a partial plan view of a superabrasive grain wheel for precision cutting according to one embodiment of the present invention.

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

FIG. 3 is a bottom view showing a state after use of the superabrasive wheel for precision cutting shown in FIG. 2;

FIG. 4 is a cross-sectional view illustrating a method for manufacturing a superabrasive wheel for precision cutting according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Mother abrasive layer 3 Tackle-shaped chip 4 Outer mold 5 Medium mold 6 Upper mold 7 Lower mold

Continuation of front page (56) References JP-A-61-131874 (JP, A) JP-A-1-121177 (JP, A) JP-A-2-292166 (JP, A) JP-A-63-207565 (JP) , A) Japanese Utility Model 3-16209 (JP, U) Japanese Utility Model 2-100773 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B24D 5/12 B24D 5/14

Claims (2)

(57) [Claims] 1. A superabrasive wheel for precision cutting with abrasive layer contiguous to the outer peripheral portion, the short-length tip of the wear rate different wear rate of the abrasive grain layer on both side surfaces of the abrasive grain layer Buried in a zigzag pattern, and
A superabrasive grain wheel for precision cutting, wherein the thickness is 1/3 to 2/3 of the width of the abrasive layer . 2. A precision cutting machine having a continuous abrasive layer on the outer periphery.
In the cutting superabrasive grain wheel, when the working hardness of the same abrasive grain layer on both sides of the abrasive grain layer is set to 100, the working hardness of the tangle-like superabrasive grain layer chip is 50 to 50. 90, or 110
150 tangled chips are buried in a zigzag pattern
At the same time, the thickness of the tangled tip is 1 / of the width of the abrasive layer.
3-2 / 3 to precision cutting superabrasive wheel you, characterized in that the.