JPH0655455A - Diamond grinding wheel and its manufacture - Google Patents

Abstract

PURPOSE:To form a uniform abrasive grain layer regardless of a ratio of length to width of each diamond abrasive grain in a grinding wheel in which the diamond abrasive grain layer is bonded on the outer circumference of a substrate so as to be integrally sintered. CONSTITUTION:A metallic core 11 is made up of metallic plates 14 and 15 and of a green compact 16 which is sintered so as to be contracted. A diamond abrasive grain layer 2 is pressed by an upper and a lower punch 12 and 13 in between the core and each outer frame 10, both the core 11 and the upper and lower punches 12 and 13 are then pressed together by pressing plates 17 and 18. By this constitution, the green compact 16 is sintered so as to let the core 11 be contracted, so that the whole of the abrasive grain layer 2 is thereby uniformly pressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diamond grindstone in which a diamond abrasive grain layer is integrally sintered on the peripheral surface of a base and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a diamond grindstone used for cutting and the like, a grindstone in which a cylindrical diamond abrasive grain layer 2 is sintered around an outer periphery of a base 1 as shown in FIG. It has been known. Further, as shown in FIGS. 5 and 6, an arcuate diamond abrasive grain layer 2 is formed on the outer peripheral surface of the base 1.
There is also a modified diamond whetstone that has formed.

FIG. 7 shows a manufacturing method for manufacturing the above conventional diamond grindstone. In the figure, 10
Is an outer frame of the mold, 11 is a core, 12 is an upper punch of the mold, 1
A lower punch 3 has a metal powder containing diamond abrasive grains incorporated between the outer frame 10 and the core 11.

The above metal powder is cold pressed and then hot pressed. This hot pressing includes a hot pressing method in which pressure is applied while heating and a hot sizing method in which pressure is applied after heating. However, when hot pressing is performed in this manner, the outer frame 10 and the core of the die are pressed. The metal powder sinters between 11 and becomes a metal sintered body (diamond abrasive grain layer 2) containing diamond abrasive grains.

The core 11 is made of a metal such as steel, a non-sintering material such as an aluminum alloy, or a copper alloy. Normally, the surface of the core 11 is plated with copper, and the diamond abrasive grain layer 2 is sintered. The abrasive grain layer 2 and copper plating are adhered and integrated. The core 11 integrated with the abrasive grain layer 2 is then trimmed to the thickness of the abrasive grain layer 2 and a mounting hole or the like is provided in the central portion to form a base 1 for a diamond grindstone as shown in FIG. To use as.

[0006]

However, in the above-mentioned conventional diamond grindstone and the manufacturing method thereof, when the thickness T of the diamond abrasive grain layer 2 in FIG. 4 exceeds 10 times the width X, or in FIGS. In the irregular-shaped abrasive grain layer shown in, the thickness T
Is more than 5 times the width X and the deformation amount K of the abrasive grain layer 2 exceeds 3 times the width X, the central portion of the diamond abrasive grain layer 2 is sufficiently pressed between the molds. However, there is a problem of insufficient sintering.

This is due to the frictional force generated between the metal powder and the surfaces of the outer frame 10 and the core 11 when the metal powder containing diamond abrasive grains is pressed by the upper and lower punches 12, 13. .

That is, when the length T of the abrasive grain layer 2 becomes larger than the width X, the above frictional force becomes remarkably large in proportion thereto, and the pressing force of the upper and lower punches 12, 13 becomes the central portion of the abrasive grain layer 2. Phenomenon that is not fully transmitted to. in this case,
The abrasive grain layer 2 is sufficiently sintered at both end portions close to the pressing position of the punches 12 and 13, but the central portion has insufficient pressurization and insufficient sintering, and thus has many pores and a low density. Become a layer. Therefore, it is difficult to form a uniform diamond abrasive grain layer 2 with a diamond grindstone in which the ratio of the length of the abrasive grain layer to the conventional width is large, and the grindstone also has a drawback that stable processing performance cannot be obtained. .

Therefore, an object of the present invention is to provide a diamond grindstone capable of reliably forming a uniform abrasive grain layer regardless of the length-width ratio of the diamond abrasive grain layer, and a method for producing the same. .

[0010]

In order to solve the above-mentioned problems, the diamond grindstone of the present invention has a base on which a diamond abrasive grain layer is sintered, a non-sintered material, and a firing sandwiched between them. It is formed from a binder.

Further, according to the manufacturing method of the present invention, the mold core is formed of a non-sintered material and a sintered material sandwiched between the core and the diamond core between the core and the outer frame. The grain layer was hot pressed, and then the core and the diamond abrasive grain layer were hot pressed together.

In the above manufacturing method, the surface of the non-sintered material of the core is metal-plated, and the diamond abrasive layer and the sintered material of the core are formed by a material that is adhered to the metal plating by sintering. Good to do.

[0013]

In the above diamond grindstone and its manufacturing method, the diamond abrasive grain layer is hot-pressed between the core (base) and the outer frame, and then both the core and the diamond abrasive grain layer are hot-pressed. Then, the sintered material inside the core causes sintering, and the volume shrinks. Therefore, the core contracts in the pressing direction, and the pressing force applied to the core (base) is evenly transmitted to the entire diamond abrasive grain layer.

[0014]

EXAMPLE FIG. 1 shows a diamond grindstone of an example. In the figure, 1 is a disk-shaped substrate, and this substrate 1 is formed of two metal materials 3 and 4 and a metal sintered body 5 sandwiched between them. A cylindrical diamond abrasive grain layer 2 is sintered and integrally bonded to the outer peripheral surface of the substrate 1.

On the other hand, FIGS. 2 and 3 show a manufacturing method for forming the above-mentioned diamond grindstone. As shown in FIG. 2, the core 11 of the mold is composed of metal plates 14 and 15 which are divided into two, and a green compact 16 which is sandwiched between the metal plates 14 and 15. .

The metal plates 14 and 15 are each plated with copper on the outer peripheral surface which is joined to the diamond abrasive grain layer 2 and the inner surface which contacts the green compact 16.

The green compact 16 has a porosity of 40% to 6%.
It is in the range of 0%, and when hot pressed, it causes sintering and shrinks, and at the same time, copper-plated metal plates 14, 15
It is formed of a metal powder that has the property of adhering to the surface of. For this, for example, cold-pressed copper powder or bronze powder is used.

On the other hand, the upper and lower punches 12 and 13 inserted between the core 11 and the outer frame 10 have their rear end portions moved toward and away from each other by the driving of a driving means (not shown). Is connected to the pressure plate 17, 1
The hot pressing is carried out by approaching and separating by 8. Further, as shown in FIG.
Prior to hot pressing by the pressure plates 17, 1, 1.
Predetermined gaps 19 and 19 are formed between the metal plate 8 and the metal plates 14 and 15 of the core 11, respectively.

The diamond abrasive grain layer 2 incorporated between the outer frame 10 and the core 11 is formed by ring-shaped charging with metal powder containing diamond abrasive grains. As a component of the metal powder, a material that adheres to the copper plating of the metal plates 14 and 15 by sintering is used, and for example, a metal bond material mainly containing copper, tin, cobalt or the like is used.

In the mold having the above-mentioned structure, when the mold is put in a furnace and heated, and in this state, the pressure plates 17 and 18 are driven to approach each other, the upper and lower punches 12,
Pressure is applied to 13 and sintering of both ends of the diamond abrasive grain layer 2 proceeds.

Next, the rear ends of the upper and lower punches 12 and 13 are at the same height as the core 11 as shown in FIG.
When the plates 7 and 18 contact the metal plates 14 and 15, the pressure plate 1
A pressing force is applied from 7 and 18 to the core 11.

By this pressing force and heating, the sintering of the green compact 16 inside the core 11 proceeds, and the volume of the green compact 16 contracts. Therefore, the core 11 gradually shrinks in the pressing direction, and the pressing force of the pressure plates 17 and 18 directly acts on the entire diamond abrasive grain layer 2, and the sintering of the central portion of the abrasive grain layer 2 is promoted. To be done. Thereby, the sintering of the diamond abrasive grain layer 2 proceeds almost uniformly over the entire abrasive grain layer,
A uniform abrasive grain layer 2 is formed.

As the above-mentioned sintering progresses, the diamond abrasive grain layer 2 and the green compact 16 adhere to the copper plating on the surfaces of the metal plates 14 and 15 to integrate the core 11 and the abrasive grain layer 2. .

The core 11 thus integrated with the abrasive layer 2
1 is formed as a diamond grindstone substrate 1 by forming the same thickness as the abrasive grain layer 2 as shown in FIG. 1 and providing a mounting hole 6 in the central portion.

In the above embodiment, the diamond abrasive grain layer 2 has been described as a grindstone having a straight cylindrical shape, but as shown in FIGS. 5 and 6, the irregularly shaped diamond having the abrasive grain layer 2 in an arc shape. The present invention can be similarly applied to a grindstone.

Further, although the single-layer green compact 16 is sandwiched between the cores 11, a multi-layer green compact may be laminated between a plurality of metal plates and sandwiched.

<Experimental Example> The metal plates 14 and 15 of the core 11 are formed of S25C, the surface thereof is plated with copper having a thickness of 10 μm, and a # 325 mesh copper powder is placed between the metal plates 14 and 15. The cold pressed green compact 16 was inserted.

The diamond abrasive grain layer 2 is made of copper 80.
%, 20% tin powder was mixed with 6% diamond abrasive grains having a grain size of 100, and the powder was cold pressed to form.

The die has an outer frame 10 having an inner diameter of 100 mm, a core 11 having an outer diameter of 94 mm, and the diamond abrasive grain layer 2 has a width X.
Was 3 mm. Further, the core 11 is made up of the metal plates 14 and 15
And the green compact 16 has a thickness of 30 mm before hot pressing, and the core 11 as a whole has a thickness of 9 mm.
It was formed to a thickness of 0 mm.

In the above specifications, first, the pressure plate 17,
A pressure of 300 kg is applied to the upper and lower punches 12 and 13 by the 18 to make the diamond abrasive grain layer 2 4
Hot pressed for 5 minutes.

Next, a pressure of 25 tons is applied to the core 11 and the upper and lower punches 12 and 13 and hot pressing is performed for 30 minutes to form the core 1.
1 was compressed to a thickness of 75 mm, and a diamond abrasive grain layer 2 having a thickness of 3 mm was obtained.

The diamond grindstone formed as described above was removed from the outer frame 10 of the mold, and both end portions and the central portion of the diamond abrasive grain layer 2 were cut and microscopically observed. As a result, pores were extremely small in each part of the abrasive grain layer 2, and a uniform abrasive grain layer was observed.

[0033]

As described above, according to the present invention, the core is contracted together with the diamond abrasive grain layer by hot pressing so that the pressing force is applied to the entire diamond abrasive grain layer. The effect is that sintering can be uniformly promoted by adding the above, and a uniform diamond layer can be formed regardless of the ratio of the length to the width.

[Brief description of drawings]

FIG. 1 is a sectional view showing a diamond grindstone of an embodiment.

FIG. 2 is a cross-sectional view showing a manufacturing process of an example.

FIG. 3 is a sectional view showing the operating state of FIG.

FIG. 4 is a sectional view showing a conventional diamond grindstone.

FIG. 5 is a sectional view showing another conventional example.

FIG. 6 is a sectional view showing another conventional example.

FIG. 7 is a sectional view showing a conventional manufacturing process.

[Explanation of symbols]

 1 Substrate 2 Diamond Abrasive Grain Layer 3, 4 Metal Material 5 Metal Sintered Body 10 Outer Frame 11 Core 12 Upper Punch 13 Lower Pattern 14, 15 Metal Plate 16 Powder Compact 17, 18 Press Plate

Claims (3)

[Claims] 1. In a diamond grindstone in which a diamond abrasive grain layer is sintered on a peripheral surface of a base to integrate them, the base is a non-sintered body and a sintered body sandwiched between them. A diamond grindstone characterized by being formed from. 2. A method for producing a diamond grindstone in which a diamond abrasive grain layer is pressed between an outer frame of a mold and a core, and the diamond abrasive grain layer is integrally sintered with the core. It is formed of a non-sintered material and a sintered material sandwiched between them, and the diamond abrasive grain layer is hot pressed between the core and the outer frame, and then the core and the diamond abrasive layer are formed. A method for manufacturing a diamond grindstone, which comprises hot pressing together. 3. The surface of the non-sintered material of the core is metal-plated, and the diamond abrasive layer and the sintered material of the core are formed of a material that adheres to the metal plating by sintering. The method for manufacturing a diamond grindstone according to claim 2, which is characterized in that.