JPH0671700B2 - Centrifugal forming method of grinding wheel - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in a method for manufacturing a grinding wheel using centrifugal casting, in which the surface of the wheel has an uneven shape, a wavy curve, or a segment. This is a centrifugal molding method for grinding wheels that can be used for other types of grinding wheels.

[Conventional technology]

As a prior art related to the present invention, there is a publication of JP-A-58-94971, "Method for manufacturing superabrasive grinding wheel". Explaining this with reference to FIG. 6, an abrasive grain holder 40 holds the inner circumferential surface of the cavity of the centrifugal casting mold so that the tips of the abrasive grains 1a, 1b, ... Contact the inner circumferential surface of the cavity, And after setting the whetstone base metal 41 in the center part of the cavity, inject the molten metal 43 of the abrasive grain fixing metal into the gap between the whetstone holder 40 and the whetstone base metal 41, as shown in 42 By rotating and dispersing to the grindstone holder 40 side by centrifugal force, the abrasive grains are fixed to the outer peripheral surface of the grindstone base through the abrasive grain fixing metal, and then the abrasive grain fixing metal outer periphery is ground. There is described a method for producing a grinding wheel in which the height of the abrasive grains of the wheel is made uniform by removing the grain holder.

However, this conventional grinding wheel has the following problems. That is, (1) because the abrasive grains are held by the abrasive grain holder to produce a grindstone by centrifugal casting, the diameter of the abrasive grains is not uniform, the direction in which the abrasive grains adhere to the holder, and the situation Some of the abrasive grains are buried in the holder, or due to the metal for fixing the abrasive grains, some of the abrasive grains that are not properly retained are partially generated, and the abrasive grains are easily peeled off.

(2) In order to prevent the embedding of the abrasive grains, it is necessary to make a thin film for holding the abrasive grains into a tape, and to attach and detach it to the mold, and it takes a lot of man-hours to align the grain size and shape of the abrasive grains. .

(3) Since there is no heating device and the hot water flows through the base metal with the runner to the abrasive grain holding layer, casting defects such as burrows may occur near the abrasive grains due to defective spinning. , The abrasive grain holding power is reduced.

(4) In order to strongly fix the abrasive grains, it is necessary to quickly replenish the molten metal with a large centrifugal force, and in the axial rotation type, obtaining a large centrifugal force is an unreasonable point in manufacturing a grindstone.

[Problems to be solved by the invention]

Therefore, the present invention, when manufacturing a grinding wheel utilizing centrifugal casting, without using a thin film holder to make the height of the abrasive grains uniform, a strong abrasive grain holding force of the grindstone Therefore, a technical problem is a method of manufacturing a grindstone capable of making the height of abrasive grains uniform.

[Means for solving problems]

Technical measures taken to solve the above-mentioned problems are as follows: a first step of applying a release agent to the inner peripheral surface of a cylindrical mold, and a cylindrical base material made of Al alloy to the inner peripheral surface of the mold. And a second step of arranging with a predetermined gap, a third step of densely filling the gap with a bonding agent for maintaining the abrasive grains and the arrangement of the abrasive grains in the same state as at the time of the regular filling, and the mold. Heating the base material to melt the base material, and at the same time rotating the mold with the center of the mold as a rotation axis to disperse the melted base material toward the inner peripheral surface of the mold by centrifugal force; The fifth step of cooling the mold to solidify the melted base material to form an abrasive grain layer in the gap, and removing the mold, etching the surface of the abrasive grain layer to expose the abrasive grains and form a grindstone The sixth step is included.

In this case, a high-frequency heating device is used as the melting device to melt in a short time.

Also, as a method of manufacturing segment type grindstone, considering the dispersion of abrasive grains in the mold of cylindrical grindstone, after preprocessing the shape of the base material into a toothed cylindrical shape, insert it into the mold. Then, fill the gap with the mold with abrasive grains mixed with a binder, put the mold into a melting furnace, heat and melt the Al base material, etc., and then install the mold in a swing rotation type centrifuge. Then, the molten metal is impregnated into the abrasive grain layer by centrifugal force and solidified to form a grindstone, which is then etched to obtain a grindstone for grinding.

[Operation of technical means]

According to the above technical means, since the abrasive grains and the array of the abrasive grains are densely filled in the gap between the base material and the mold for maintaining the same state as that at the time of filling, the abrasive grains The thickness of the layer can be secured, and the abrasive grain layer can be multilayered. as a result,
Even if the abrasive grains formed on the surface of the abrasive grain layer fall off when the grindstone is used, the abrasive grains exist inside the abrasive grain layer.
Therefore, the life of the grindstone is improved. Also, the mold is heated to melt the base material, and at the same time, the mold is rotated to disperse the melted base material toward the inner peripheral surface of the mold by centrifugal force, and then the base material is cooled and solidified. As a result, the melted base material is solidified in a state of permeating around the abrasive grains existing in the gap, and as a result, the abrasive grains are firmly bonded to the base material. Therefore, peeling of the abrasive grains can be prevented.

〔Example〕

 Examples of the above technical means will be described below.

Reference numeral 1 is a rotational molding device, 2 is a rotating body, a heating device 3 is provided, and 3a is a heater. 4 is a rotary plate, 5 is a motor, 6 is a temperature controller, and 6a is a thermocouple. Reference numeral 7 is a cold air blowing hose, and 8 is a lid of the rotating body.

Reference numeral 9 denotes the entire mold, which is mounted on the rotating body 2 and rotated.
10 is a mold, 11 is a mold lid, and 12 is a seal. 13 is a mold release agent inside the mold, 14 is abrasive grains (diamond abrasive grains or KUVEC / boron nitride-CBN), and 15 is Al.
Alternatively, it is a base material made of a Cu alloy.

The manufacturing method will be described with the above configuration. (A) A mold release agent 13 (peel coat, die bar, die-coat, ...) Is applied to the inside of the mold 10 and dried, and then (b) Al or Cu alloy. A base material 15 made of, and filled in a gap 18 between the die and the base material (adjustable by the size of the base material) with a mixture of the abrasive grains and the binder as shown in 19, or Heat the particles with a brush or the like to disperse the abrasive grains to a density of 60% or less on the inner surface of the mold evenly, then (c) cover the lid and heat the mold 10 to melt the base material, then Centrifugal force (100 to 1000 G) is applied as shown in the rotation direction 20, (d) the abrasive grain layer is heated and impregnated with the molten metal by centrifugal force, and centrifugal force is added while maintaining high temperature to improve the bathing condition. .

The temperature setting at this time is controlled by the temperature controller 6 and the thermocouple 6a, and at the time of cooling, cold air is sent by the hose 7 to adjust the cooling rate. As a result, as shown in (e), an abrasive grain layer 23 is formed on the surface of which the abrasive grains 1a, 1b, 1c are aligned by the centrifugal force. After that, an etching process (sodium hydroxide solution or the like) is performed to project the abrasive grains, and the abrasive grains are projected to form a grindstone for grinding.

Next, as a modified example, as shown at 22 in FIG. 3, there is one in which the grindstone surface has a triangular shape, which is composed of the abrasive grain layer 23 and the base material 24. As shown in FIG. 4 and FIG. 25, there is a grindstone having a corrugated surface, which is composed of an abrasive grain layer 26 and a base material 27, each of which is a split mold, and is manufactured by the same manufacturing method as described above. Can be formed.

5, the protrusions 29a, 29b, ... Are provided, and the base material 30 and the abrasive grain layer 3 are provided.
1 is molded by centrifugal force in a mold.

(Peculiar effect produced by the present invention) The present invention produces the following peculiar effect. That is, in addition to those that perform centrifugal rotation with a vertical axis rotation type, there are those that perform centrifugal rotation with a swivel type.In addition to a cylindrical grindstone, other shapes, that is, a shape with irregularities on the grindstone surface, or a wavy shape It is also possible to manufacture something with a large wave shape.

In addition, in order to manufacture a grindstone under high temperature, the coagulation time is slow, so the bathing time is good, the abrasive layer is well impregnated with hot water, the retention of the abrasive is sufficient, and the centrifugal force is controlled. By doing so, the degree of concentration of the abrasive grains can be adjusted freely.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of the present embodiment, in which (a) shows a rotational molding device, (b) shows a mold, and (c) shows a grindstone.
FIG. 2 is a process explanatory view of this embodiment, (a) is a process of inserting a base material into a mold, (b) is an abrasive grain filling process, (c) is a heating centrifugal force process, and (d) is It is a forming process, and (e) is an enlarged view of an abrasive grain layer. 3 and 4 are cross-sectional views of a modified embodiment, FIG. 5 is another modified embodiment, (a) is a plan view of a partially omitted grindstone, and (b) is (a). FIG. 3 is a plan view of the mold of FIG. FIG. 6 is a conventional example, (a) is a cross-sectional view during centrifugal formation, and (b) is a cross-sectional view in which abrasive grains are peeled off. 1a, 1b, 1c …… Abrasive grains, 3 …… Heating device, 9 …… Mold, 15…
… Base material, 19… Abrasive grains and binder

 ─────────────────────────────────────────────────── ─── Continuation of the front page Examiner Sadao Enjoji (56) References JP-A-58-94971 (JP, A) JP-A-58-90465 (JP, A)

Claims (1)

[Claims] 1. A first step of applying a release agent to the inner peripheral surface of a cylindrical mold, and a cylindrical base material made of an Al alloy with a predetermined gap from the inner peripheral surface of the mold. A second step of arranging, a third step of densely filling the gap with a binder for maintaining the abrasive grains and the arrangement of the abrasive grains in the same state as at the time of always filling, and heating the mold A fourth step of melting the base material, and at the same time rotating the mold with the center of the mold as a rotation axis to disperse the melted base material toward the inner peripheral surface of the mold by centrifugal force; A fifth step of cooling the mold to solidify the molten base material to form an abrasive grain layer in the gap, removing the mold, and etching the surface of the abrasive grain layer to expose the abrasive grains. And a sixth step of forming a whetstone by a centrifugal force.