JPH07299599A - Method for forming green compact containing grinding stone grain - Google Patents

Abstract

PURPOSE:To obtain a green compact containing grinding stone grain that is excellent in workability, productivity and quality by filling a rubber mold attached to a metallic die with powder containing grinding stone grain, compressing the rubber mold between the metallic die and an upper punch to form a green compact containing grinding stone grain, and then performing calcination or hot press. CONSTITUTION:The device H for forming a green compact is constituted such that a mold M, powder feeders S1-S3, preliminary compressor B, main compressor P, conveyor device T, cleaning device C and transfer device D for a tubular guide member are successively arranged around a revolving table h1. The powder feeders S1-S3 forms a green compact W consisting of three powder layers. With the compressors B, P provided, the conveyor device T takes out the green compact W from a rubber mold m1, placing it on the transfer device t12. In addition, the cleaning device C cleans the rubber mold m1 from which the green compact W is taken out. The green compact thus obtained is processed through calcination or hot press, and a tool (grinding stone) with the grinding stone grain dispersed for cutting and other uses is thereby manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder or granules containing abrasive grains in a rubber mold (hereinafter referred to as powder or granules,
Simply called "powder". ) Is filled, then compressed using the pressure applied by the punch and the deforming force of the rubber in the rubber mold,
The present invention relates to a method for molding a green compact containing abrasive grains.
By firing or hot pressing the green compact molded in this way, a tool in which abrasive grains are dispersed, which is used in various industrial fields as a tool for cutting, grinding, and polishing (hereinafter, simply referred to as "grinding stone" It is manufactured.

[0002]

2. Description of the Related Art Conventionally, a grindstone used for cutting, grinding, polishing or the like is filled with powder containing abrasive grains in a die, pressed to form a green compact, and then fired or hot pressed. It is manufactured by

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention As described above, in the conventional green compact molding method in which powder containing abrasive grains is filled in a mold and then pressed to form green compacts, diamond abrasive grains or Cubic Boron Nitride (Cubic Boron
Nitride, (CBN)) abrasive grains, and further, because the hardness of the abrasive grains is higher than the hardness of the material of the mold, such as SiC and Al ₂ O ₃ , Due to the molding work, the mold is significantly worn, and the mold must be replaced frequently, resulting in a huge mold cost or a decrease in productivity due to the mold replacement. There is a problem that the manufacturing cost of the

Since diamond abrasive grains and cubic boron nitride abrasive grains are very expensive, they are precisely weighed and filled in a mold, and such expensive diamond abrasive grains or cubic boron nitride are saved. In order to improve the machinability, these abrasive grains are blended at a high density in a necessary portion of the grindstone, and no abrasive grains are blended in an unnecessary portion, or,
Although it has been devised to mix powders at low densities, it takes considerable skill and time to fill powders with different abrasive grain densities in multiple layers in a mold, and therefore it takes time to fill them. Therefore, there is a problem that the press efficiency of the die press is deteriorated and the manufacturing cost of the grindstone is further increased. Also,
Since press equipment such as an upper punch and a press column is arranged above the die, powder containing abrasive grains can be precisely measured and filled into the die, or multiple layers can be filled. It is difficult to install a powder supply device that can do this, and precision powder feeding and multi-layer powder feeding of powders containing such abrasive grains to the mold are performed manually, and therefore pressure powder containing abrasive grains is used. The productivity of the powder is extremely poor, and the quality of the green compact containing abrasive grains is also poor.
Furthermore, there is a problem that it is difficult to form a green compact containing abrasive grains of uniform quality.

Further, since the above-mentioned conventional pressing apparatus is uniaxial, the pressure distribution in the green compact containing the abrasive grains to be compressed is not uniform, so that the green compact is cracked, chipped or fired. There are problems such as time cracks. Furthermore, when the green compact containing abrasive grains is taken out of the mold by the raising of the lower punch, the green compact containing abrasive grains is formed due to the strong friction between the green compact containing abrasive grains and the inner surface of the mold. There is a problem that it is distorted or damaged.

An object of the present invention is to solve the problems of the above-described conventional method for molding a green compact containing abrasive grains, and
It is an object of the present invention to provide a method for molding a green compact having excellent workability and productivity and containing high quality abrasive grains.

[0007]

In order to achieve the above object, the present invention firstly fills a rubber mold mounted on a mold with powder containing abrasive grains, and then molds. And the upper punch placed on the die, the rubber mold is compressed to form a green compact containing abrasive grains. Secondly, it is mounted on the die. The rubber mold is filled with abrasive-containing powder in a layered manner stepwise or continuously, and then the rubber mold is compressed between the die and the upper punch placed on the die to remove the abrasive grains. Thirdly, a green compact containing the abrasive grains is formed by compressing the rubber mold between a die and an upper punch placed on the die. After molding, the powder compact containing abrasive grains was removed from the rubber mold, and the rubber molding from which the powder compact containing abrasive grains was removed. It is those that so as to clean the,
Fourth, powder containing abrasive grains is supplied to the rubber mold mounted on the mold and the cylindrical guide member placed on the mold, and then the rubber mold and the grinding guide supplied to the cylindrical guide member are supplied. The powder containing abrasive grains is filled into the rubber mold by compressing the powder containing grains, and then the rubber mold is compressed between the die and the upper punch placed on the die to produce abrasive grains. A green compact containing is molded.

By the way, a grindstone is used in various industrial fields such as metal working, excavation or cutting in mining and civil engineering, machining of precious metals, grinding and polishing in medical equipment, grinding or polishing in machine tools, etc. Etc., and there are various shapes as shown in Japanese Industrial Standard (JIS) B4131. Therefore, in the embodiment of the present invention, FIG. 1 mainly used for cutting stone or asphalt.
A method for forming a green compact containing abrasive grains (hereinafter, also simply referred to as “green compact”) for manufacturing a grindstone used for a disc-shaped cutting tool shown in FIG. However, the present invention can be applied to the molding of a green compact containing abrasive grains for the production of grindstones of various compositions or shapes.

Further, the grindstone is classified into a resin-bonded type, a metal-bonded type, and a so-called vitrified bond type using glass or ceramic depending on the difference in the binder used. In the present invention, a metal-bonded grindstone that uses a metal powder as a binder is mainly targeted, but the present invention is produced by once compression-molding the powder at room temperature, and then firing at atmospheric pressure or hot pressing. Therefore, even in the case of other bonding types, the present invention is effective when a powder containing abrasive grains is once compression-molded and then fired or hot pressed to produce a grindstone.

In the disk-shaped cutting tool Y shown in FIG. 1, y1 has a mounting hole y1 'for mounting on a cutting machine or the like in the central portion, and is recessed at appropriate intervals along the circumference. y1 ″ is a disk-shaped base metal part, and the material of the base metal part y1 is an aluminum alloy casting, carbon tool steel, or the like. y2 is a green compact molded by the present invention described later. The grindstone y2 is a segment-shaped grindstone manufactured by firing or hot pressing, and the grindstone y2 is usually formed around the space between the recesses y1 ″ of the base metal part y1 by C
It is fixed by brazing with d, Cu, Ag or the like or by welding with an electron beam or the like.

In the present invention, for example, diamond abrasive grains or CBN abrasive grains are used as the abrasive grains, and metal powder is used as the binder. It will be used for molding. As a grain, depending on the use, 60 to 12 for a rough grindstone.
0 mesh, 120-325 mesh for fine finishing grindstone, 325-1000 mesh for high precision grindstone,
Further, a grindstone for lapping has a size of 1000 mesh or more. Larger abrasive grains may be used for the dressing tool grindstone.

The material of the metal powder as the binder is roughly classified into Cu type, Fe type, W, Mo type, WC type, etc.
Cu-Sn, Cu-Sn-Co, Cu-P, C is used for u system.
Fe-Ni, Fe-Ni-C for u-Be alloy, Fe system
r, Ni-Be alloy, W-Ni-Cu for W, Mo system,
Mo-Cu-Co alloy, WC-based WC with Co13-2
An alloy containing 0% or Ni25% is used.
The particle size of the metal powder is, for example, 325 mesh or less in the case of Cu—Sn alloy powder, and the particle size of 1.5 μm is used in the case of mixing the Co powder. When using any other powder, a very fine powder is used for forming a dense and high-strength matrix. Further, an organic additive such as zinc stearate or PVA (polyvinyl alcohol) may be added to improve the fluidity of the powder or to improve the moldability during compaction.

Further, the ratio of the abrasive grains to the binder powder is such that when 25% by volume of abrasive grains are contained in the grindstone after firing (in this way, the concentration of 25% by volume of abrasive grains is 100%) as a standard, and is adjusted according to the application, grade, and, in the case of a multi-layer type grindstone, the position in the grindstone. The compounding ratio of the abrasive grains as the mixed powder is about 5 to 20% by weight, and may be further increased or decreased depending on the application. The mixed powder of the above abrasive grains and the binder powder is filled in the rubber mold mounted in the mold. At the time of filling, a guide described below is attached to the upper surface of the mold to guide or After the mixed powder is first filled in the rubber mold, the powder is pushed into the rubber mold by a pusher such as a vertical rod having a compression plate attached to the tip described later. The powder filling will be described later in detail with reference to the case of multi-layer filling.

As will be described later, the present invention fills a rubber mold with a mixed powder containing abrasive grains and then simultaneously compresses the rubber mold and the powder with a die and a punch to form a green compact. Therefore, no friction occurs between the abrasive grains and the mold wall during compression. Therefore, the problem of friction between the abrasive grains and the mold wall in the conventional method in which the mixed powder containing the abrasive grains is directly charged into the mold and compressed by the punch is solved. According to an experiment, when a mixed powder containing abrasive grains such as diamond was compacted, a large number of scratches were made on the steel mold wall in one molding. Then, the mold wall was worn away due to the repeated molding of about 500 times, and the clearance between the mold and the punch became too large, resulting in compression failure. However, in the method of the present invention, the problem of wear of the mold wall did not occur at all, and the abrasive grains were strongly pressed against the rubber mold during compression, but no damage to the rubber mold was observed. After the repeated compression test of about 500 times, the rubber mold was still in a usable state.

In order to efficiently fill and compress the powder,
A mold equipped with a rubber mold as illustrated in FIGS. 8 and 9 described later is used. The details of this method will be described for the case of multi-layer filling, but the most important point is that the lower punch is always inserted in the mold, and the rubber formed in the space formed by the die and the lower punch that constitutes the mold. The mold is attached, and the die attached with the rubber mold can be carried out of the press machine as it is. This method is extremely effective for improving productivity even in the case of single layer filling (filling with only one kind of mixed powder).

A rubber mold made of silicon rubber having segment-shaped depressions as shown in FIG. 2 is mounted on the mold shown in FIG. 8 and Cu-10S is used.
n alloy (325 mesh) and Co (1.5 μm) 20
-80% by weight of metal-bonded powder and diamond abrasive (30
(Mesh, 120 mesh, 325 mesh) various mixed powders were prepared and repeated compaction molding test was conducted. The compression was performed at 0.5 t / cm ² and 1 t / cm ² . As a result, the green compact could be molded with any compression pressure, and no damage was observed in the rubber mold or the mold even after repeated compression of 500 times.

From this, in particular, the method of the present invention using a mold and a rubber mold as shown in FIG. 8 or 9 is a method of compacting a metal-bonded mixed powder containing abrasive grains such as diamond. It was proved to be extremely useful for body shaping. That is, when the above-mentioned mixed powder is compressed by a conventional die press to form a green compact, the die is 500
It had to be replaced every time. Since the mold is very expensive and it takes a long time for a skilled worker to replace it,
The ratio of die cost and die replacement cost to the product was enormous. In the method of the present invention, the rubber mold is not damaged by the compression of hard abrasive grains such as diamond, and since the abrasive grains do not rub the die wall, die wear does not occur. . Also, the rubber mold can be made immediately by pouring the liquid rubber into the mother mold if one mother mold is made of a material that is easy to process, such as aluminum, and since the liquid rubber raw material is inexpensive, the rubber mold is made of gold. It is much cheaper than the mold. Further, the replacement of the rubber mold is extremely simple as compared with the replacement of a heavy die in the conventional die set, requires no skill, and can be performed in a short time. Furthermore, since the mold equipped with the rubber mold as shown in FIG. 8 or FIG. 9 is configured so that it can be carried out of the compression device, precise weighing and filling of powder outside the compression device. Is possible. In this way, by molding a compact containing abrasive grains according to the present invention, it is possible to reduce expensive mold costs and mold replacement costs in the conventional method, greatly improve the productivity, and compress. Since the powder can be precisely weighed, filled and leveled outside the apparatus, the molding cycle time of the green compact can be significantly shortened and the cost of the grindstone can be reduced.

When the method of the present invention is applied to the production of a multi-layered grindstone, in addition to the drastic reduction of the die cost and die replacement cost and the shortening of the cycle time, a great improvement can be made. That is, in order to manufacture a multi-layered grindstone by the conventional die press method, different powders are sequentially filled in a die, and after the powders are filled in multiple layers, the powder is compression-molded by the upper and lower punches, and then the lower punch. It has to be pushed up to take out the green compact, and in particular, the multi-layer filling of the powder takes time, and the pressing cannot be performed during that time, so that the molding cycle time of the green compact becomes very long. The productivity of the green compact was extremely poor. In particular, the problem of cycle time for multi-layer packing was much more serious than for single-layer packing. As described above, precision weighing, filling, and leveling of powders are difficult to automate in conventional press machines, and most of them are manually performed by hand, which results in low productivity and quality. Was not stable either. Further, even if it is automated, it takes a considerable time to fill the three-layer type powder, and it is extremely difficult to improve the productivity. As will be described below, according to the present invention, it is possible to realize an automated apparatus which facilitates multi-layer filling and has a compacted powder compacting cycle time which is a fraction or less of that of a conventional pressing apparatus by a simple automated mechanism. Became.

When resin powder is used as the binder (resin-bonding type) as described above, resin powder such as phenol resin or epoxy resin is mixed with abrasive grains such as diamond or CBN. Further, SiC powder is added to prevent abrasion of the resin, and solid lubricant such as MoS ₂ or graphite is added to impart lubricity. Further, metal powder such as Ag or Cu may be added to improve thermal conductivity. Resin-bonded grindstone can be used directly at 150 ℃ without preforming.
It is often pressure-molded while being heated at 200 ° C. However, since the present invention solves the problem of die wear, once the above-mentioned mixed powder is pressure-molded with a die and a punch using a rubber mold at room temperature to form a green compact, Next, with a hot press machine, 150 ℃ ~ 200 ℃
The means for pressure molding is effective. That is, performing the two-stage molding in this way is advantageous over the conventional direct heating and pressure molding (hot pressing) method in which pressure molding is performed while directly heating in the following points. (1) In the method of the present invention, the amount of the mixed powder filled in the rubber mold is precisely weighed and compression-molded, and the compression-molded green compact is hot-pressed. Therefore, the grindstone unit weight (per one grindstone) Weight) will be controlled very precisely,
Therefore, variations in the shape and size of the grindstone as a product are small. Also, since it takes no time to fill the die of the hot press machine having poor productivity with the green compact, the productivity as a whole is improved and the cost of the grindstone can be reduced. (2) Multi-layer filling of mixed powders having different abrasive grain concentrations into the mold of the hot press machine is extremely difficult from the viewpoint of productivity and the structure of the hot press machine. According to the method of the present invention, multi-layer filling can be easily carried out and a green compact having a multi-layer structure can be molded without causing a problem due to friction between the green compact and the mold. In the method of the present invention, a multilayer grindstone can be easily produced by molding a multi-layered green compact and then pressure-molding it with a hot press. The multi-layered grindstone is a high-concentration distribution of high-priced abrasive grains to the parts required for cutting and grinding, and has a great effect on saving abrasive grains and improving cutting and grindability.

Glass called a vitrified bond type,
Also in the case of the ceramic-bonded grindstone, as in the case of the resin-bonded grindstone, the abrasive grains and Al ₂ O ₃ , SiO ₂ , water glass,
When a mixed powder of powders such as silicate is directly put into a hot press mold and pressure-molded, the method of the present invention is not effective, but once preformed at room temperature to prepare a green compact, The method of the present invention is very effective when hot-pressing this or firing at normal pressure.

Depending on the purpose and field of use of the grindstone such as grinding, polishing or cutting, the material and size of the work piece, the shape of the grindstone, etc., the amount of the abrasive grains, binder powder and filler powder compounded different. In particular, when using expensive diamond abrasives, the higher the degree of concentration, the more expensive the grindstone, so reduce the degree of concentration of the part that makes little contribution to cutting to reduce the cost of the grindstone. Is being done. For example, in the case of the green compact W consisting of three layers shown in FIG. 2A, which is a perspective view of the green compact W before being baked into a grindstone, the upper layer w1 and the lower layer w3 are large. Since it is a portion that contributes to cutting, the concentration of diamond abrasive grains in the upper layer w1 and the lower layer w3 is set to, for example, 100, and the contribution to the cutting is small compared to the upper layer w1 and the lower layer w3.
The price of the grindstone is reduced by setting the degree of concentration of the grinder to 25, for example.

As described above, the powder compact W shown in FIG. 2A has an abrasive grain concentration of 100, for example.
Although it is composed of three layers different from 25 and 100 in stages, it is also possible to change the concentration substantially continuously. Thus, the green compact W formed so that the composition of the green compact W changes stepwise or continuously is also called a functionally gradient green compact. The green compact W shown in FIG. 2B is formed by using one kind of powder containing abrasive grains, and thus the powder compact containing one kind of abrasive grains is used. W can be molded, or a green compact W containing abrasive grains composed of two or more layers can be molded as needed.

The above-mentioned functionally graded powder compact is generally defined as powders of different kinds constituting the powder compact that are stacked stepwise or continuously. The target means, for example, that the powder composition forming each layer changes stepwise, and the continuous means that the powder composition forming each layer changes substantially continuously. For example, a stepwise functionally graded powder compact composed of powder (X) and powder (Y) means that the first layer is a layer composed only of powder (X),
The powder composition of each layer such that the second layer is composed of a mixed layer containing 50% by weight of each of the powder (X) and the powder (Y) and the third layer is composed of only the powder (Y). Is a functionally graded powder compact that changes in a stepwise manner, and a continuous functionally graded powder compact is a layer of powder (X) only, followed by a substantially continuous powder (Y) powder. It is a functionally functioning powder compact whose composition continuously changes so that the amount increases and finally a layer consisting of only powder (Y) is formed. In addition,
The above-mentioned powders of different types include not only powders of different materials and powders of different compositions, but also powders of the same material but different in particle size or shape.

Specific examples of the present invention will be described below, but the present invention is not limited to these examples as long as the gist of the present invention is not exceeded.

First, FIG. 3 is a vertical sectional view taken along the center line of a mold or the like, which will be described later, FIG. With reference to FIG. 5, which is a front view of the cleaning device, the molding sequence of the green compact W composed of three layers as shown in FIG. 2 will be outlined.

First, as shown in FIG. 3 (a), a cylindrical guide member G is placed on a mold M, which will be described later, and then a rubber mold m1 mounted on the mold M, A powder supply device S described later supplies, for example, a mixed powder having a concentration of 100 to form a first powder layer as shown in FIG. 3B. Next, a mixed powder having a concentration degree of 25 is supplied, a second powder layer is laminated on the above-mentioned first powder layer, and finally, a mixed powder having a concentration degree of 100 is supplied. By laminating the powder layers of the first layer, a laminated body composed of three layers in total is formed. If the surface of the powder dropped from the powder supply device S does not become flat, a leveling step can be added if necessary. The leveling process includes a method of tapping the mold M and the tubular guide member G, a method of leveling the surface of the powder with a leveling plate or a brush, and the like.

Next, as shown in FIG. 3 (d), a compression plate b4 'attached to the tip of a vertical rod b4, which will be described later, is inserted into the through hole g1 of the tubular guide member G, and the rubber is inserted. A powder layer consisting of three layers laminated in the mold m1 and the tubular guide member G is pre-compressed, and the entire powder layer is in a high density state in the rubber mold m1 as shown in FIG. 3 (e). To fill.

After the powder of the first layer is supplied to the rubber mold m1, the compression plate b4 'attached to the tip of the vertical rod b4 is inserted into the through hole g1 of the cylindrical guide member G, and 1
After compressing the powder of the second layer and then supplying the powder of the second layer by the powder supply device S, the compression plate b attached to the through hole g1 of the tubular guide member G at the tip of the vertical rod b4 again.
The step of inserting 4'and compressing the powder of the second layer may be sequentially repeated to supply and compress the powder for each layer. Further, after omitting the cylindrical guide member G, the powder of the first layer is directly supplied to the rubber mold m1, and then the powder of the first layer is compressed by an appropriate pressing member such as the compression plate b4 ′. Then, the step of directly supplying the powder of the second layer by the powder supply device S to the rubber mold m1 and then compressing the powder of the second layer by the pressing member is sequentially repeated.
It is also possible to fill the rubber mold m1 with powder.

Next, after removing the tubular guide member G placed on the die M, the upper punch p1 is placed on the die M, as shown in FIG. Figure 3
As shown in (g), the upper punch p1 is lowered to highly compress the powder layer contained in the rubber mold m1 to form the green compact W.

Next, as shown in FIG. 4, the unloading device T, which will be described later, is used to remove the powder compact W from the rubber mold m1.
After being taken out, it is placed on the transfer device t12 and transferred to the next step such as firing. After that, as shown in FIG. 5, the powder remaining in the rubber mold m1 is removed by the cleaning device C described later, and the series of molding steps of the green compact W is completed.

Next, with reference to FIG. 6 which is a perspective view of the die M, the tubular guide member G and the compression plate b4 'attached to the tips of the vertical rods b4, the die M and the tubular guide described above are used. Member G
Also, the outline of the compression plate b4 ′ attached to the tip of the vertical rod b4 will be described.

The mold M, which will be described later, has a segment-shaped recess m corresponding to the shape of the green compact W as shown in FIG.
A rubber mold m1 having 1'perforated is attached,
As shown in FIG. 3A, the tubular guide member G is placed on the mold M on which the rubber mold m1 is mounted. A vertical through hole g1 is formed in the cylindrical guide member G, and the horizontal cross-sectional shape of the through hole g1 is a rubber mold m at a predetermined height from the lower end portion g1 ′ of the through hole g1.
1 is formed in the same shape as the planar shape of the segment-shaped depression m1 ′ of FIG. 1, and the upper end portion g1 ″ of the through hole g1 is larger than the powder outlet of the powder supply device S described later, for example,
It is formed in a substantially circular shape. Through hole g of cylindrical guide member G
The horizontal cross-sectional shape of at least the lower end of the compression plate b4 ′ of the vertical rod b4 inserted into the vertical rod b4 is the same as the planar shape of the segment-shaped recess m1 ′ of the rubber mold m1. By inserting the compression plate b4 ′ of b4 into the through hole g1 of the cylindrical guide member G, as shown in FIG.
As shown in (e), the powder layer supplied to the rubber mold m1 and the tubular guide member G is compressed, and the entire powder layer is filled in the rubber mold m1 at a high density.

The lower end portion g of the through hole g1 of the tubular guide member G
The horizontal cross-sectional shape of 1 ′ does not necessarily have to be the same as the planar shape of the segment-shaped depression m1 ′ of the rubber mold m1, and is at least smaller than the planar shape of the segment-shaped depression m1 ′ of the rubber mold m1. The horizontal cross-sectional shape of the lower end portion g1 ′ of the through hole g1 of the tubular guide member G may be the segment-shaped depression m of the rubber mold m1.
If it is smaller than the planar shape of 1 ', the rubber mold m1
When the powder layer laminated in the tubular guide member G is compressed by the compression plate b4 ′ inserted into the through hole g1 of the tubular guide member G, the powder laminated in the tubular guide member G is Since the laminated powder layers are disturbed due to the lateral movement of the rubber mold m1 when moving into the rubber mold m1, as described above, the horizontal cross-sectional shape and compression of the lower end portion g1 ′ of the through hole g1 are suppressed. It is preferable that the horizontal cross-sectional shape of at least the lower end portion of the plate b4 ′ is formed in the same shape as the planar shape of the segment-shaped depression m1 ′ of the rubber mold m1. With this configuration, the powder layer laminated in the rubber mold m1 and the tubular guide member G can be compressed substantially vertically, and therefore, the lateral movement of the powder can be prevented and the powder layer Disturbance can be suppressed.
When the powders supplied into the rubber mold m1 and the cylindrical guide member G have the same composition, the laminated powder layers are not disturbed as a matter of course. It is not necessary to form the horizontal cross-sectional shape of the lower end portion g1 'and the horizontal cross-sectional shape of at least the lower end portion of the compression plate b4' to the same shape as the planar shape of the segment-shaped recess m1 'of the rubber mold m1.

Next, FIG. 7 is a perspective view of a green compact molding apparatus H for carrying out the green compact molding method including abrasive grains of the present invention.
A series of molding steps of the above-described green compact W will be described using.

Reference numeral h1 is a known rotary table which is disposed on the machine base h2 of the green compact molding apparatus H and is intermittently rotated by an appropriate driving means (not shown).
A predetermined number of molds M to be described later are placed on the mold 1 in accordance with the number of molding steps of the green compact W. S1 to S3 are, for example,
These are powder supply devices to be described later that supply mixed powders having a concentration of 100, a concentration of 25, and a concentration of 100, respectively (the powder supplying devices S2 and S3 are omitted and shown by a chain double-dashed line). For the sake of convenience, a case of molding a green compact W composed of three powder layers as shown in FIG. 2 will be described. Therefore, in FIG. 7, three powder supply devices S1 to S3 are provided. It is shown.

B and P are a pre-compression device and a main compression device, which will be described later, which are arranged in the gate-shaped frame h3 arranged on the machine stand h2, and T is a powder compact from the rubber mold m1. A carrying-out device for taking out the body W and placing it on an appropriate carrying device t12 such as a belt conveyor. Further, C is a cleaning device for cleaning the rubber mold m1 from which the green compact W is taken out. Is.

The powder supply devices S1 to S3, the preliminary compression device B, the main compression device P, the unloading device T and the cleaning device C described above.
Are sequentially arranged around the turntable h1.

D is to place the cylindrical guide member G on the mold M prior to supplying the powder to the rubber mold m1, and after the pre-compression is completed and before the main compression, from the mold M. A device for removing the tubular guide member G (hereinafter, simply,
It is called a "cylindrical guide member transfer device". ), Which is installed on an appropriate frame provided in a machine base h2 (not shown) and holds the cylindrical guide member G by a clamper d.
A swiveling rod d4, on which 9, 9 and the like are arranged, is provided so as to project from a through hole h1 ′ formed at the center of the turntable h1.

The mold M, the powder supply device S, the preliminary compression device B, the main compression device P, the unloading device T, the cleaning device C, and the cylindrical guide member transfer which compose the above-described green compact molding device H are described below. The device D will be described.

First, the mold M mounted on the rotary table h1 will be described with reference to FIG. 8 which is a vertical sectional view taken along the center line of the mold M. h4 is a donut-shaped mold holding frame attached to the rotary table h1 by a suitable fastener such as a bolt (not shown), and the mold holding frame h4 has a substantially columnar mold described later. Support member m of mold M
A through hole h4 'into which 2 is inserted is provided. h5 is
It is a horizontal hole opened toward the inner wall side of the mold holding frame h4, and an appropriate number of holes are provided in the radial direction. A coil spring h6 is built in the horizontal hole h5, and the tip end of the coil spring h6. Is provided with a ball h7 urged by a coil spring h6 so that a part thereof protrudes from the horizontal hole h5.

The outer wall of the supporting member m2 of the mold M is provided with a groove m3 along the circumferential direction in which the tip of the ball h7 can be fitted. Through hole h
4 ', the tip of the ball h7 urged by the coil spring h6 fits into the concave groove m3 formed in the outer wall of the support member m2, and the support member m2 of the mold M is rotated. The mold M can be attached to the mold h1, and the mold M can be pulled out from the through hole h4 ′ of the mold holding frame h4 by lifting the mold M upward.

M4 is a columnar lower punch body, the lower part of the lower punch body m4 is fitted in a recess m2 'provided on the upper surface of the support member m2, and the lower punch body m4.
Is a through hole m2 ″ formed in the center of the support member m2 and a bolt m5 in a bolt hole m4 ′ formed in the lower punch body m4.
Is attached on the support member m2 by inserting the support member m2, and the support member m2 and the lower punch body m4 constitute a lower punch m6. m7 is a substantially cylindrical die, a lower punch m6 is inserted into the die m7, and a spring member m8 such as a disc spring is provided between the lower end of the die m7 and the upper surface of the support plate m2. It is arranged. Also, m9
Is a substantially disc-shaped backup plate made of hard synthetic resin, which is attached to the upper end of the lower punch body m4. The rubber mold m is provided in the gap between the lower punch body m4 and the die m7.
It is intended to prevent 1 from being bitten.

A rubber mold m1 having a recess m1 'corresponding to the shape of the green compact W to be molded is mounted in the recess m10 formed by the lower punch m6 and the die m7. In addition, m11 is provided on the upper end of the die m7,
A ring-shaped convex portion g hung at the lower end of the cylindrical guide member G
2 or a notch into which a protrusion p1 ′ of an upper punch p1 described later is fitted.

The mold M fitted in the mold holding frame h4 is arranged on the rotary table h1 according to the number of molding steps of the powder compact W. FIG. 7 shows a three-stage powder supply process performed by the powder supply devices S1 to S3, a preliminary compression process by the preliminary compression device B, a main compression process by the main compression device P, and a powder compact from the rubber mold m1 by the discharge device T. The green compact W is molded by the eight steps of carrying out the body W, cleaning the rubber mold m1 by the cleaning device C, and transferring the tubular guide member G onto the mold M by the guide member transfer device D. In this example, at least eight molds M fitted into the mold holding frames h4 are arranged on the rotary table h1.

Similar to FIG. 8, FIG. 9 is a vertical sectional view taken along the center line of the mold M. Unlike the mold M described above, FIG. 9 shows an example in which the mold M is fixedly mounted on the rotary table h1. The mold holding frame h4 is omitted, and the support member m2 of the mold M is directly attached to the rotary table h1 by the bolts m11 and m11 ′. When it is not necessary to remove the mold M from the rotary table h1 as in another powder compacting apparatus to which the method of the present invention described later is applied, the mold M is fixed to the rotary table h1 as described above. It can also be installed.

Next, according to the number of powder supply steps, the machine base h
An example of the powder supply apparatus S will be described with reference to FIG. 10, which is a front view including a partial cross section of the powder supply apparatus S disposed around the rotary table h1 on the second table.

S1 is a vertical shaft standing on the machine stand h2, and a spur gear s2 is fixed to the vertical shaft s1. s
Reference numeral 3 denotes a box-shaped rotating frame attached to a tip portion s1 ′ of the vertical shaft s1 via an appropriate bearing s4, and a bottom portion s3 ′ of the rotating frame s3 has a tip end with the above-mentioned spur gear. A forward / reverse rotatable motor s5 having a substantially vertical output shaft s5 'to which a pinion s6 screwed to s2 is attached is provided. Therefore, by driving the motor s5 and rotating the pinion s6 screwed to the spur gear s2, the rotating frame s3
Can be rotated about a vertical axis s1 provided upright on the machine base h2.

Reference numeral s7 is a vertical rod erected on the upper surface s3 "of the rotating frame s3, s8 is a vertical screw shaft provided in parallel with the vertical rod s7, and vertical screw shaft s8 is a rotating frame. A pulley s9 'attached to the output shaft of a forward-reverse rotatable motor s9 arranged in s3, an endless belt s10, and a pulley s8' attached to the lower end of the vertical screw shaft s8 It is configured to be rotated by driving s9, and s11 is a connecting plate attached to the upper end of the vertical rod s7 for pivotally attaching the upper end of the vertical screw shaft s8.

Reference numeral s12 is a moving frame, and the moving frame s12 has two horizontal arms s having screw holes s13 'in which screw grooves for engaging with the above-mentioned vertical screw shaft s8 are engraved.
In addition, the vertical bar s7 described above is inserted into the guide hole s13 ″ formed at the tip of the horizontal arm s13. Therefore, the forward / reverse rotatable motor s9 is
By appropriately driving and rotating the vertical screw shaft s8 via the pulley s9 ′, the endless belt s10, and the pulley s8 ′, the horizontal arm s13 having the screw hole s13 ′ screwed into the vertical screw shaft s8 is attached. Moving frame s12
Can be moved up and down with the vertical rod s7 as a guide.

Reference numeral s14 is a powder guide hole provided in the moving frame s12. The powder guide hole s14 is provided with two reticulated filters s15 arranged at predetermined intervals in the vertical direction. Has been done. Mesh filter s15
Is attached to one end of rod s16, and rod s1
The other end of 6 is connected to an eccentric cam (not shown) attached to the output shaft of the motor s17. Therefore, by rotating the motor s17,
The rod s16 is reciprocated in the horizontal direction via the eccentric cam, and the mesh filter s15 attached to the rod s16.
Is capable of vibrating in the horizontal direction. Although FIG. 10 shows an example in which two reticulated filters s15 are provided, one filter may be provided or two or more filters may be provided as necessary. Note that various known means can be applied as the vibrating means of the mesh filter s15, and the mesh filter s15 can also be vibrated in the vertical direction.
It is also possible to vibrate both horizontally and vertically.

S18 is a powder container for storing mixed powder having a predetermined concentration, and the powder container s18
A shutter s19 capable of controlling the degree of opening and closing of the powder outlet s18 'is disposed at the powder outlet s18' of the powder outlet s18 '. It is attached to the driven shaft s19 '. By rotating the shaft s19 ′, as shown in FIG.
By moving 9 to the horizontal position, the powder outlet s1
8'is closed to prevent the powder from falling, and the axis s19 '
The powder outlet s18 'can be opened by rotating the shutter s19 in the vertical direction to rotate the shutter s19 between the horizontal position and the vertical position. By adjusting, the amount of powder falling from the powder outlet s18 'of the powder storage container s18 can be controlled. The powder dropped from the powder outlet s18 'of the powder storage container s18 is positioned downward from the powder drop opening s14' of the powder guide hole s14 while falling like rain due to the horizontally oscillating mesh filter s15. It is supplied to the rubber mold m1 mounted on the mold M and the tubular guide member G mounted on the mold M.

As shown in FIG. 10, the powder feeding device S is located above the die M and the cylindrical guide member G mounted on the die M at the powder feeding step position in the non-operating position. It is in a standby position away from. From such a standby position, first, the motor s9 capable of forward and reverse rotation is driven to rotate the vertical screw shaft s8 via the pulley s9 ', the endless belt s10, and the pulley s8' to move the moving frame s1.
2 is moved upward so that the lower end of the moving frame s12 does not hit the mold M and the tubular guide member G. Next, the motor s5 is driven to rotate the pinion s6 screwed to the spur gear s2, thereby rotating the rotating frame s3.
Is rotated about a vertical axis s1 erected on the machine base h2 to move the moving frame s1 as shown in FIG.
The moving frame s12 is rotated so that the powder drop opening s14 ′ of the second powder guide hole s14 is located above the mold M and the tubular guide member G located below. Then, the motor s9 capable of rotating in the forward and reverse directions is driven to move the powder guide hole s14.
The moving frame s12 is lowered until the powder dropping port s14 'of the above is located near the upper end of the cylindrical guide member G located below.

In the embodiment of the present invention, three powder supply devices S as described above are arranged as shown in FIG. 7. For example, the powder supply device S1 has a concentration of 100. The mixed powder of No. 1 is stored, and the powder supply device S2 stores the mixed powder of the concentration degree of 25,
Furthermore, the powder supply device S3 stores mixed powder having a concentration of 100. Then, the shutter s19 is opened on the rubber mold m1 and the tubular guide member G of the mold M located below the powder supply device S1 to make the concentration 10
0 powder mixture is supplied and the first powder layer is laminated,
In addition, the concentration degree 100 moved to the lower side of the powder supply device S2
The rubber mold m1 and the cylindrical guide member G, in which the first powder layer of the mixed powder of No. 2 is laminated, are supplied with the mixed powder having the concentration degree of 25 by opening the shutter s19 of the powder supply device S2. Of the mixed powder having a concentration of 100 and a second powder layer of the mixed powder having a concentration of 25, which have moved to the lower part of the powder supply device S3. The rubber mold m1 and the tubular guide member G are configured such that the powder mixture of the concentration 100 is supplied by opening the shutter s19 of the powder supply device S3 and the third powder layer is laminated.

FIG. 12 is a front view of a powder feeder S similar to that of FIG. 11 showing another embodiment of the powder feeder S. In this embodiment, in addition to the above-described powder container s18, the same The powder storage container s20 having the above configuration is provided, and for example, the powder storage container s18 stores the abrasive grains, and the powder storage container s20 stores the mixed powder of the binder powder and the filler powder separately. Is configured to be able to. Similar to the powder storage container s18, the powder outlet s20 ′ of the powder storage container s20 has a powder outlet s.
A shutter s2 capable of controlling the opening / closing degree of 20 '
1 is provided, and the shutter s21 is attached to a shaft s21 'which is rotationally driven by a suitable driving means such as a motor or a fluid cylinder (not shown).

As described above, the two powder storage containers s1
In the powder supply device S in which 8, s20 are provided, powder (X) such as abrasive grains is stored in the powder storage container s18, and powder such as binder powder is stored in the powder storage container s20. (Y) is accommodated, powder (X) and powder (Y)
A cylindrical guide placed on the rubber mold m1 and the mold M of the powder supply device S in which the above-described two powder storage containers s18 and s20 are arranged, for example, in the case of molding the green compact W consisting of The means for supplying the powder to the member G will be described.

The shaft s19 'of the shutter s19 arranged at the powder outlet s18' of the powder container s18 containing the powder (X) is rotated by an appropriate driving means,
The shutter s19 is moved to the vertical position to be fully opened, and the powder storage container s20 in which the powder (Y) is stored.
Shutter s21 arranged at the powder outlet s20 'of
The shaft s21 'is rotated by an appropriate driving means to move the shutter s21 to the horizontal position and close it. In this state, only the powder (X) falls on the filter s15,
The powder (X) moves like rain due to the vibration of the filter s15. The powder drop hole s1 of the powder guide hole s14 of the frame s12.
It is dropped from 4 ′ and supplied to the rubber mold m1 and the tubular guide member G.

Then, the shaft s19 'of the shutter s19 arranged at the powder outlet s18' of the powder container s18 containing the powder (X) is rotated by an appropriate driving means to move the shutter s19 to the vertical position. From the above, the shaft s21 'of the shutter s21 arranged at the powder outlet s20' of the powder container s20 containing the powder (Y) is rotated by an appropriate driving means at the same time. The shutter s21 is gradually moved in the vertical direction from the horizontal position. In this state, the filter s1
The powder (X) and the powder (Y) both fall on the surface of the rubber 5, and the powder (X) and the powder (Y) are mixed by the vibration of the filter s15, and the rubber mold m1 and the tubular guide member G. Is supplied to.

As described above, the shutter s19 provided at the powder outlet s18 'of the powder container s18 containing the powder (X) is gradually moved horizontally from the vertical position and at the same time the powder ( The powder (X) is mixed with more powder (Y) than the powder (Y) by gradually moving the shutter s21 arranged at the powder outlet s20 ′ of the powder container s20 containing Y) from the horizontal position in the vertical direction. From the powder, the powder (X) and the powder (Y) are in the same amount, and a mixed powder containing more powder (Y) than the powder (X) is supplied to the rubber mold m1 and the tubular guide member G.

The shutter s19 arranged at the powder outlet s18 'of the powder container s18 containing the powder (X) gradually moves in the horizontal direction from the vertical position until the shutter s19 becomes completely horizontal. When the powder (X) is closed, the powder (X) stops falling from the powder outlet s18 ′ of the powder storage container s18, and the powder (Y) is placed at the powder outlet s20 ′ of the powder storage container s20. The shutter s21 gradually moves in the vertical direction from the horizontal position, and when it becomes completely vertical, the shutter s21 is fully opened.
Only the powder (Y) is supplied to the rubber mold m1 and the tubular guide member G. Then, after a predetermined amount of powder (Y) is supplied to the rubber mold m1 and the tubular guide member G, the shaft s21 ′ of the shutter s21 is rotated to move the shutter s21 from the vertical position to the horizontal position. The shutter s21 is closed to stop the supply of the powder (Y) and stop the supply of both the powder (X) and the powder (Y).

With the powder supply device S as described above, the powder (X) is applied to the rubber mold m1 and the cylindrical guide member G.
A layer made of only powder, a layer made of a mixed powder in which the powder (X) is larger than the powder (Y), a layer made of a mixed powder in the same amount of the powder (X) and the powder (Y), and a powder (X) ) It is possible to form a powder layer at a previous stage of the green compact W formed of a layer composed of more mixed powder and a layer composed of only the powder (Y). Of course, by intermittently driving the shaft s19 'and the shaft s21' and gradually moving the shutter s19 and the shutter s21 at a predetermined interval, the powder can be laminated in a stepwise inclined state, and the powder ( X) and the powder (Y) are mixed in the same amount, the shutter s21 arranged at the powder outlet s20 'of the powder storage container s20 containing the powder (Y) is moved in the closing direction, and
A shutter s19 provided at a powder outlet s18 'of a powder container s18 containing powder (X) is moved in the fully opening direction to form a powder layer composed of only powder (X) on the upper and lower sides. You can also In any case, a powder layer having various mixed compositions can be formed by appropriately controlling the apertures of the shutter s19 and the shutter s21. Further, by arranging three or more powder storage containers, it is possible to form a mixed powder composed of a larger amount of powder.

In the embodiment shown in FIG. 7, the powder supply devices S1 to S3 are arranged on the machine base h2 side, and the intermittent rotation of the rotary table h1 causes the powder supply devices S1 to S3 to be located below the powder supply devices S1 to S3. An example in which the mold M and the tubular guide member G are moved is shown. In this case, each powder supply device S1 to S
3 shows the opening degree of the shutter s19 on the powder storage container s18 side storing the powder (X) and the opening degree of the shutter s21 on the powder storage container s20 side storing the powder (Y). When the mold M and the tubular guide member G are arranged below each of the powder supply devices S1 to S3, they are stored in a computer or the like that is not stored, and the stored opening is instantaneously changed from the closed state. Shutters s19 and s21 are opened each time, and each powder supply device S1
Powders having different compositions of the powder (X) and the powder (Y) are supplied to the rubber mold m1 and the tubular guide member G located below S3 to S3, respectively, and the pressure at which the composition between the layers changes stepwise. It is applied when the powder W is molded. For example,
Abrasive grains such as diamond abrasive grains or cubic boron nitride abrasive grains are stored in the powder storage container s18, and the powder storage container s2
The binder powder and the filler powder are stored in 0, and the mixed powder having the concentration of 100 from the powder supply device S1, the mixed powder having the concentration of 25 from the powder supply device S2, and the powder supply device S3. The shutter s19 on the powder container s18 side so that the mixed powder having the concentration of 100 is supplied to the rubber mold m1 and the tubular guide member G located below.
By controlling the opening degree of the above and the opening degree of the shutter s21 on the powder storage container s20 side, it is possible to mold the green compact W composed of three layers as shown in FIG.

Further, each powder supply device S1 corresponding to the mold M and the tubular guide member G arranged on the rotary table h1.
Each of ~ S3 can be arranged on the turntable h1. In this case, since the same powder supply devices S1 to S3 are always arranged above the respective molds M and the tubular guide member G, in this case, the powder containing the powder (X) is contained. The opening degree of the shutter s19 on the storage container s18 side and the powder storage container s2 containing the powder (Y)
This is applied to a case where the openness of the shutter s21 on the 0 side is continuously controlled to form the green compact W whose composition is continuously changed. Of course, in this case as well, each powder supply device S
By 1 to S3, powders having different compositions of the powder (X) and the powder (Y) can be supplied, and the green compact W in which the composition between layers is changed stepwise can be molded.

FIG. 13 is a front view of the powder supplying apparatus S similar to that of FIG. 12, showing another embodiment of the powder supplying apparatus S.
Except for the points described below, the powder feeder S has the same configuration as that shown in FIG. 12, and thus the same components are designated by the same reference numerals.

S50 is located below the powder falling from the shutter s19 arranged at the powder outlet s18 'of the powder container s18 and the shutter s21 arranged at the powder outlet s20' of the powder container s20. An air injection pipe s51 for injecting compressed air from a nozzle s51 ′ is a guide tube for guiding the rubber mold m1 and the tubular guide member G, and is provided at the center of the guide tube s50. The air injection pipe s51 goes out from the guide pipe s50 at an appropriate position and is connected to a compressed air source such as a compressor (not shown). The powder descending in the guide tube s50 via the shutters s19, s21 arranged below the powder outlets s18 ', s20' is compressed air injected from a nozzle s51 'located near the outlet s50' of the guide tube s50. Is sprayed in a mist state by and is supplied to the rubber mold m1 and the tubular guide member G.

FIG. 14 is a front view of a powder supplying apparatus S similar to that of FIG. 12, showing still another embodiment of the powder supplying apparatus S. In this embodiment, the powder supplying apparatus S is erected on the machine stand h2. A rotating frame s configured to be rotatable about the vertical axis s1.
3 is omitted, and the motor s9 capable of rotating in the normal and reverse directions is
It is arranged in a box-shaped frame s60 mounted on the machine base h2, and the box-shaped frame s60 is provided with the vertical rod s7 and the vertical screw shaft s8 shown in FIG. Therefore, the moving frame s12 only moves in the vertical direction with respect to the mold M and the cylindrical guide member G placed on the mold M, and is disengaged from above the mold M and the cylindrical guide member G. It does not rotate to the position. The other configuration is the same as the configuration shown in FIG. 12, and thus the description is omitted.

FIG. 15 which is a partially enlarged view of the powder feeder S.
The powder guide hole s14 of the moving frame s12 shown in FIG.
A fixed filter s70 is attached in the vicinity of the powder dropping port s14 ′ in place of the above-described vibrating filter s15. Above the fixed filter s70, there is a brush that comes into contact with the upper surface of the fixed filter s70. A rotary plate s71 on which hair is planted is arranged. A vertical shaft s72 having a sprocket s72 'attached to the center of the rotating plate s71.
On the other hand, a motor s73 having a sprocket s73 'attached to the output shaft is provided at an appropriate position on the moving frame s12, and is attached to the vertical shaft s72 of the rotating plate s71. A chain s74 is stretched over the sprocket s72 'and the sprocket s73' attached to the output shaft of the motor s73. Therefore, by driving the motor s73, the sprocket s7
The rotating plate s71 on which the brush is implanted can be rotated via the 3 ', the chain s74, and the sprocket s72'.

As described above, the rotating plate s71 on which the brushes that contact the upper surface of the fixed filter s70 are implanted.
By rotating the powder outlet s18 ', s20'
The powder dropped onto the fixed filter s70 from the shutters s19 and s21 arranged below the fixed filter s70 by the rotating plate s71 on which the rotating brush is applied.
It is evenly dispersed on the upper side, and is supplied from the mesh of the fixed filter s70 in a rain state to the rubber mold m1 and the tubular guide member G located below.

Next, referring to FIG. 7 and FIG. 16 which is a front view of the preliminary compression device B and the main compression device P, the preliminary compression device B and the main compression device P will be described.

B1 is a horizontal portion h3 'of the portal frame h3.
The vertical frames h10 and h10 'that are formed in the vertical frame h10' are lateral frames attached to the lower ends of the guide rods b2 and b2 'that are inserted into the vertical holes h10 and h10', respectively. The piston rod b3 'of the hydraulic cylinder b3 mounted on the horizontal portion h3' of the portal frame h3 is attached to the vertical portion b1 '. Therefore, the horizontal frame b1 can be moved in the vertical direction by operating the hydraulic cylinder b3 and moving the piston rod b3 'up and down.

In the horizontal portion b1 "of the horizontal frame b1, the above-mentioned compression plate b4 'which can be inserted into the through hole g1 of the cylindrical guide member G mounted on the mold M and which is attached to the vertical end is attached vertically. A bearing b5 for supporting and guiding the rod b4 is provided, and a motor b6 is mounted on the horizontal portion b1 ″ of the horizontal frame b1 and the horizontal output shaft of the motor b6 is eccentric. A rotary plate b7 having a pin b7 'protruding from the position is attached. Reference numeral b8 denotes a support column which is erected on the horizontal portion b1 ″ of the horizontal frame b1 between the vertical rod b4 and the motor b6. The support rod b8 has a pin at one end thereof protruding from the rotary plate b7. The lever b9, into which the horizontal projection b4 ″ attached to the vertical rod b4 is fitted, is pivotally attached to the long hole b9 ′ into which the b7 ′ is fitted and which is formed at the other end. . With this configuration, the motor b6 is driven to rotate the rotating plate b7 having the pin b7 ′ projecting at the eccentric position, so that the end of the lever b9 where the long hole b9 ′ is formed. The part can be moved up and down around the support b8 as an axis to move up and down the vertical rod b4 having the horizontal projection b4 ″ fitted in the elongated hole b9 ′ of the lever b9.

Therefore, the compression plate b4 'of the vertical rod b4 which can be inserted into the through hole g1 of the tubular guide member G is lowered,
As described above, as shown in FIG. 3D, the powder filled in the through hole g1 of the tubular guide member G is compressed,
The rubber mold m1 can be filled with high density.
It should be noted that the compression plate b4 ′ is provided with pores that do not allow powder to pass therethrough, and the cylindrical guide member G and the compression plate b4 ′ are pre-compressed.
Air existing between the pores is released to facilitate precompression,
It can also be configured to do so quickly. In this way, the preliminary compressing step of compressing and filling the powder supplied to the rubber mold m1 and the tubular guide member G into the rubber mold m1 with high density by the powder supply device S is completed. After the pre-compression process is completed, the motor b6 is appropriately rotated to raise the vertical rod b4, and the compression plate b
4'is removed from the through hole g1 of the tubular guide member G, the hydraulic cylinder b3 is operated, and the piston rod b3 'is moved upward to move the horizontal frame b1 to the upper standby position.

The above-mentioned motor b6, the rotating plate b7 or the lever b having a pin b7 'protruding from the eccentric position.
By omitting 9 etc., in the horizontal part b1 ″ of the horizontal frame b1,
It is also possible to arrange the cylinder so that the piston rod is positioned vertically, attach the compression plate b4 ′ to the tip of the piston rod, and move the compression plate b4 ′ up and down by the operation of the cylinder.

P2 is a horizontal portion h3 'of the portal frame h3.
It is a horizontal frame attached to the lower ends of the guide rods p3 and p3 'inserted into the two vertical holes h11 and h11', respectively, and the upper punch p1 is attached to the lower surface of the horizontal frame p2. Worn, and also in horizontal frame p
At the upper part of 2, the piston rod p4 'of the hydraulic cylinder p4 mounted on the horizontal part h3' of the portal frame h3.
Of the upper punch p1 attached to the lower surface of the horizontal frame p2 by actuating the hydraulic cylinder p4 to move the piston rod p4 'up and down. Can be moved in the vertical direction.
It is a protrusion that fits into a notch m11 provided at the upper end of the die m7. Of course, a cutout m11 is formed at the upper end of the die m7.
When the mold M not provided with is used, such a protrusion p1 ′ can be omitted. A rubber lid that can be fitted into a recess provided in the periphery of the opening of the rubber mold m1 may be attached to the lower surface of the protrusion p1 ′.

Next, the main compression step will be described with reference to FIG. 16 and FIG. 17, which is a front view including a partial cross section of the die M, the upper punch p1, etc., showing the sequence of the main compression step.

As shown in FIGS. 3 (a) to 3 (c), the powder supply device S causes the rubber mold m1 and the tubular guide member G to have abrasive grains, binder powder, filler powder, etc. To form a powder layer, and then, as shown in FIG.
As shown in (d), the compression plate b4 ′ attached to the tip of the vertical rod b4 in the through hole g1 of the tubular guide member G.
Inserting and lowering the vertical rod b4, the powder layer is densely packed in the rubber mold m1 as shown in FIG. 3 (e), and the pre-compression step is completed.

As described above, the die M after the pre-compression process is completed by the intermittent movement of the rotary table h1 after the tubular guide member G is removed by the tubular guide member transfer device D described later. 7 and FIG. 16, it is positioned below the upper punch p1.

Then, the hydraulic cylinder p4 is actuated to move the piston rod p4 'downward, as shown in FIG.
3 (f), the upper punch p1 is lowered to the die M as shown in FIG. 3 (f).
Place. From this state, further hydraulic cylinder p
4 is operated to lower the upper punch p1,
As shown in (g) and FIG. 17 (b), the die m
7, the die m7 moves downward against the spring force of a spring member m8 such as a disc spring arranged between the lower end of 7 and the upper surface of the support plate m2, and the rubber mold m1 is inserted. The volume of the recess m10 formed by the lower punch m6 and the die m7 is reduced, so that the recess m1 ′ of the rubber mold m1 is reduced.
The powder layer filled in is compressed and the green compact W is formed. After the green compact W is molded, the hydraulic cylinder p4 is operated again to move the piston rod p4 ′ upward, and the upper punch p1 is raised.

After that, the rotary table h1 is intermittently rotated by a predetermined amount, and the mold M on which the green compact W is molded is taken out from the rubber mold m1 as shown in FIG. A suitable conveyor device t1 such as a belt conveyor
It is moved to the carry-out device T for carrying out the carry-out process, which is placed on 2.

Next, the carrying-out device T and the carrying-out process will be described with reference to FIG. 18 which is a front view including a partial cross section of the carrying-out device T and FIG. 19 which is an enlarged cross-sectional view of a main part of the suction member of the carrying-out device T. To do.

Reference numeral t1 denotes a horizontal arm which is cantilevered by an output shaft t4 'of a motor t4 arranged at the tip of a piston rod t3 of a cylinder t2 arranged on the machine stand h2. It is configured to be movable in the vertical direction, and by the rotation of the motor t4,
It is configured to be rotatable between the position shown by the solid line and the position shown by the chain double-dashed line in FIG.

Reference numeral t5 is a suction member formed of a soft material such as silicon rubber in a bellows shape. The suction member t5 is shown in FIG.
As shown in FIG. 9, it is arranged at the tip portion t1 ′ of the horizontal arm t1. The outer sleeve t7 inserted into the through hole t6 of the horizontal frame t1 ″ of the tip end t1 ′ of the horizontal arm t1 is
It is attached to the horizontal frame t1 ″ by nuts t8 and t8 ′, and the outer sleeve t7 has a suction member t at the tip thereof.
The suction tube t9 to which 5 is attached is inserted. Suction tube t
A flange portion t9 ′ provided at a predetermined position of 9 is arranged in an outer sleeve t7 having an inner diameter corresponding to the outer diameter of the flange portion t9 ′ of the suction tube t9, and is connected to the flange portion t9 ′ of the suction tube t9. Inner edge t7 ′ of the upper part of the outer sleeve t7
A coil spring t10 is arranged in between. t
Reference numeral 11 denotes a large diameter portion provided at a predetermined position of the suction pipe t9, and t9 ″ denotes a suction pipe connected to the upper end portion of the suction pipe t9, which is arranged on the machine base h2 or the horizontal arm t1. It is connected to a suction device (not shown).

Since the suction pipe t9 is constructed as described above, the suction pipe t9 is normally lowered by the coil spring t10 arranged between the flange portion t9 'of the suction pipe t9 and the inner edge t7' of the outer sleeve t7. As shown in FIG. 19, when the suction member t5 comes into contact with the upper surface of the green compact W, the suction pipe t9 is lifted against the spring force of the coil spring t10. Then, the suction member t5 is brought into pressure contact with the surface of the green compact W to such an extent that the green compact W is not damaged,
The suction member t5 is configured to surely adsorb the green compact W.

Reference numeral t12 is a suitable conveying device such as a conveyor belt arranged on the machine base h2 on the substantially opposite side with the cylinder t2 sandwiched between them. It is arranged at t13 ′ and is configured so that the transport device t12 can be operated by rotating at least one roller t14 of the transport device t12 by the motor t15. The green compact W placed on the transfer device t12 is transferred to the next step such as firing.

Next, the carry-out device T configured as described above.
Will be described. As shown in FIG. 18, the motor t4 is driven to rotate the horizontal arm t1 to position the suction member t5 above the mold M in which the rubber mold m1 containing the powder compact W is housed. . Next, the cylinder t2 is actuated to lower the piston rod t3, and a suction device (not shown) is actuated to adsorb the powder compact W by the suction member t5, and then the piston rod t3 is raised to move the rubber. Mold m1 to green compact W
Take out. Next, the horizontal arm t1 is rotated to convey the powder compact W adsorbed to the suction member t5 to the upper portion of the conveying device t12, lower the piston rod t3 again, and stop the suction operation of the suction device. Then, the green compact W is placed on the transfer device t12. After that, piston rod t3
Is raised and the horizontal arm t1 is returned to the standby position shown by the chain double-dashed line in FIG. Then, the transport device t12
The green compact W placed on the top is conveyed to the next step such as firing.

At a predetermined position of the suction pipe t9 ″, a vacuum degree detection device (not shown) for detecting the degree of vacuum in the suction pipe t9 ″ is arranged, and after the suction member t5 adsorbs the green compact W. The degree of vacuum may be detected, and when the detected degree of vacuum is low, the presence of a crack or a chipped portion in the green compact W may be appropriately detected.

After that, the rotary table h1 is intermittently rotated, and the mold M from which the powder compact W has been taken out is moved to the position where the cleaning device C is arranged to perform the cleaning step. The cleaning device C and the cleaning process will be described with reference to FIG. 20, which is a front view including a partial cross section of the cleaning device C.

C1 is a cylinder arranged on the machine base h2, and c2 is a piston rod which moves up and down by the operation of the cylinder c1. A motor c3 is mounted on the tip of the piston rod c2, and a substantially central portion of a substantially V-shaped horizontal arm c5 is attached to an output shaft c4 of the motor c3. A motor c6 mounted on one end of the horizontal arm c5
The output shaft c7 has a brush c8 attached thereto, and the other end of the horizontal arm c5 is provided with a suction pipe c9 having a suction port c9 ′. The suction pipe c9 is mounted on the horizontal arm c5. In the installed suction motor c10 for generating suction air,
It is connected via the dust box c11. In addition,
c12 is a frame c erected on the upper part of the horizontal arm c5
It is a cover for covering the upper part of the cleaning device C attached to 5 ', c5 ", and can be omitted as appropriate.

Next, the cleaning device C constructed as described above.
Will be described. In the previous process, the carry-out device T
As a result, above the rubber mold m1 from which the powder compact W has been taken out, the cylinder c1 is operated to raise the piston rod c2, and the motor c3 is appropriately driven to position the brush c8. Next, the piston rod c2 is lowered to insert the brush c8 into the rubber mold m1, the motor c6 is driven to rotate the brush c8 to remove the powder adhering to the inside of the rubber mold m1, and then the motor c6 is driven. Stop the rotation of the brush c8.

Then, the piston rod c2 is raised and the motor c3 is rotated to position the suction port c9 'of the suction pipe c9 above the rubber mold m1.
Then, the piston rod c2 is lowered to draw the suction tube c9.
The suction port c9 ′ of the rubber mold m1 or near the opening of the rubber mold m1 and the suction motor c10 is operated to generate a suction air flow in the suction pipe c9, and the rubber mold removed by the brush c8. m
The powder adhering to the inside of 1 is sucked. The powder sucked from the suction port c9 ′ passes through the suction pipe c9 and is stored in the dust box c11. Next, the piston rod c2 is raised to raise the horizontal arm c5, and the brush c8 or the suction port c9 'of the suction pipe c9 is retracted to the upper standby position until the next operation. The rubber mold m1 is cleaned by repeating the above operation.

Next, referring to FIG. 7, FIG. 21, which is a plan view of the tubular guide member transfer device D, and FIG. 22, which is a side view including a partial cross section of the tubular guide member transfer device D, the rubber is used. Prior to the supply of the mixed powder to the mold m1, the cylindrical guide member G is placed on the mold M, and after the preliminary compression is completed and before the main compression, the cylindrical guide member G is separated from the mold M. A tubular guide member transfer device D for removing and placing the tubular guide member G for removing the above will be described.

D1 is a cylinder arranged on the machine base h2, and the piston rod d1 'of the cylinder d1 is
A turning motor d3 is connected via a suitable pin d2. d4 is a vertical turning rod rotated by the turning motor d3, and the turning rod d4 drives the turning motor d3 so that the main compression in the next step is performed as shown in FIG. Then, the tubular guide member removing step position for removing the tubular guide member G from the mold M for which the pre-compression is completed, and the rubber mold m1 by the cleaning device C.
After the cleaning is completed, it is possible to swivel between the positions of the cylindrical guide member mounting process before the powder supplying process in which the powder supplying device S1 starts supplying the mixed powder. Further, the turning rod d4 is configured to be able to move up and down along the tubular guide d5 in which the turning rod d4 disposed in the machine base h2 is inserted by operating the cylinder d1.

Reference numeral d6 denotes a cylindrical horizontal frame attached to the upper end of the vertical turning rod d4, and the horizontal frame d6 accommodates a cylinder d7. d8 is a horizontal moving arm connected to the piston rod d7 ′ of the cylinder d7,
The horizontal moving arm d8 is configured to be movable in the horizontal direction while being guided by a guide block d6 ′ arranged at the tip of the horizontal frame d6 by operating the cylinder d7. d9 and d10 are substantially C-shaped clampers, one end of which is pivotally attached to a vertical pin d11 arranged at the tip of the horizontal moving arm d8, and a clamper d9 pivotally attached to the vertical pin d11, At the ends of the extension parts d9 ′ and d10 ′ extending from the end part of d10, the clamper d9,
A spring d12 for urging d10 in the opening direction is stretched.

Reference numeral d13 denotes a cylinder mounted on the horizontal moving arm d8. A tapered cam d14 is attached to the tip of a piston rod d13 'of the cylinder d13. The tip of the cam d14 is , The above-mentioned clamper d
9's extension d9 'and clamper d10's extension d10'
It is located between and. Therefore, by operating the cylinder d13 and moving the piston rod d13 'to the right in FIG. 21, the clampers d9 and d1 are moved.
Open the extension parts d9 ', d10' of 0, and clamper d9,
21. The cylinder rod d13 'is moved to the left side in FIG. 21 so as to close the d10 and the cylinder d13, thereby closing the extension parts d9' and d10 'of the clampers d9 and d10 and closing the clampers d9 and d1.
It is configured so that 0 can be opened.

With the above construction, in order to remove the cylindrical guide member G mounted on the mold M from the mold M after the pre-compression is completed, the cylinder d1, the cylinder d7 and By appropriately operating the turning motor d3, the clamper d9 disposed on the horizontal moving arm d8,
The tip of d10 is positioned on the front surface of the tubular guide member G placed on the mold M. Then cylinder d
21 is operated to move the piston rod d13 'to the left in FIG. 21 to open the clampers d9 and d10, and the cylinder d7 is operated to activate the clamper d9.
9 and d10 are further advanced, and clampers d9 and d10
A tubular guide member G is arranged in between. Then, the cylinder d13 is operated to move the piston rod d13 ′ to the position shown in FIG.
By moving to the right at
9 and d10 are closed, and the cylindrical guide member G is gripped by the clampers d9 and d10.

After that, the cylinder d1 is operated to raise the turning rod d4, whereby the cylindrical guide member G
Raise the clampers d9 and d10 holding the
By removing the tubular guide member G mounted on the mold M from the mold M and then driving the turning motor d3, the rubber mold m1 by the cleaning device C as shown in FIG. The clampers d9 and d10 that hold the tubular guide member G are arranged above the die M located between the cleaning step and the powder supply step in which the powder supply by the powder supply device S1 is started. After that, cylinder d
1 to lower the swiveling rod d4 to mount the cylindrical guide member G on the mold M and to move the cylinder d1.
3 is operated to open the clampers d9 and d10, and further,
Operate the cylinder d7 to set the clampers d9 and d10.
Is retracted to separate the clampers d9 and d10 from the tubular guide member G placed on the mold M.

By appropriately repeating the above-mentioned operation, the step of placing the tubular guide member G on the mold M and the mold M are performed.
The tubular guide member G is configured to be removed. At this time, for example, as shown in FIG. 10, the notch m11 provided in the upper end of the die m7 and the ring-shaped convex part g2 depending on the lower end of the tubular guide member G are fitted together. Thereby, the cylindrical guide member G can be reliably aligned with the mold M, and
The tubular guide member G can be stably placed on the mold M. A known hand robot may be used instead of the cylindrical guide member transfer device D having the above-described configuration.

Next, mainly using FIG. 7, the green compact W
The molding order of will be described.

First of all, the powder M is mounted on the rubber mold m1 cleaned by the cleaning device C, and the powder supplying device S1 arranged below the mold M is used to apply a predetermined powder to the rubber mold m1 or the cylindrical guide member G. For example, the degree of concentration 100
The mixed powder of is supplied and the first layer is laminated. In the powder supply device S2, the concentration degree 1 in the powder supply device S1
The mixed powder of concentration 25 is supplied onto the powder layer on which the first layer of the mixed powder of 00 is formed.
Layers are laminated, and in the powder supply device S3,
In the powder supply device S2, for example, the mixed powder having the concentration of 100 is supplied and the third layer is stacked on the powder layer on which the second layer made of the mixed powder having the concentration of 25 is formed.
As described above, each powder supply device S1 to S3 is
When arranged on the rotary table h1 corresponding to each die M, the powder is always supplied to the rubber mold m1 and the tubular guide member G of the same die M from the respective powder supply devices S1 to S3. Will be supplied.

Then, the rotary table h1 is moved by one pitch,
That is, each mold M is intermittently rotated by an amount corresponding to the movement to the next process. Due to the intermittent rotation of the rotary table h1, the die M on which the cylindrical guide member G having one powder layer formed below the powder supply device S1 is placed is located below the powder supply device S2. A cylindrical guide member G that is moved and has two powder layers located below the powder supply device S2.
The mold M on which is placed moves below the powder supply device S3, and further, the cylindrical guide member G on which three powder layers are formed, which is located below the powder supply device S3, is placed. The moving mold M moves below the preliminary compression device B in the next step,
The preliminary compression step as described above is performed.

The pre-compression process is performed by the pre-compression device B, and the tubular guide member G located below the pre-compression device B
The cylindrical guide member G is removed from the mold M on which is mounted by the cylindrical guide member transfer device D described above. The mold M from which the tubular guide member G has been removed in this way moves below the main compression device P by the intermittent rotation of the rotary table h1 described above, and the main compression process is performed.

The mold M, which has been subjected to the main compression process by the main compression device P, is sent to the carry-out device T by the intermittent rotation of the rotary table h1 described above, and, as described above, is pressed from the rubber mold m1. While the unloading process of the body W is performed, the green compact W is placed on the transfer device t12 and transferred to the next process such as sintering. Further, the die M, which has completed the unloading process by the unloading device T, is sent to the cleaning device C by the intermittent rotation of the rotary table h1 described above, and the cleaning process as described above is performed.

The mold M, which has undergone the cleaning process by the cleaning device C, of the cylindrical guide member G before the first powder layer is formed by the powder supply device S1 by the intermittent rotation of the rotary table h1 described above. After moving to the mounting position, the preliminary compression process is performed by the above-described preliminary compression device B at this position, and the tubular guide member G located below the preliminary compression device B is moved.
The cylindrical guide member G removed from the die M on which the cylindrical guide member is mounted and gripped by the cylindrical guide member transfer device D is
It is placed on the mold M for which the cleaning process has been completed by the cleaning device C. The mold M on which the cleaning process is completed and the tubular guide member G is placed moves below the powder supply device S1 due to the intermittent rotation of the rotary table h1 described above.

The mold M on which the predetermined processing has been completed in each of the above-mentioned steps or the mold M on which the tubular guide member G is mounted is sequentially rotated by intermittent rotation of the rotary table h1.
It moves to the work position of the next process, and each predetermined process is performed.

Next, FIG. 2 which is a plan view of the green compact molding apparatus.
24. FIG. 24 and FIG. 24 which are plan views of the mold supporting device E and the like.
25, which is a side cross-sectional view taken along line I-I of FIG.

The embodiment shown in FIGS.
Similar to the above-described embodiment, by the powder supply devices S1 to S3 arranged on the machine stand h2, the mold M on which the cylindrical guide member G arranged at a predetermined position of the rotary table h1 is placed,
Each of which supplies powder to form a powder layer, and then a mold M on which the cylindrical guide member G having the powder layer formed thereon is placed.
Is transferred onto the belt conveyor V arranged on the side of the rotary table h1 by using the known hand robot R1.
As described above, in this embodiment, since the mold M needs to be transferred from the rotary table h1 onto the belt conveyor V, the mold held on the rotary table h1 as shown in FIG. 8 is held. A mold M that is detachably fitted to the frame h4 is used.

The precompressor B and the main compressor P as described above are arranged along the belt conveyor V. A mold M is supported on the side portion of the belt conveyor V where the pre-compression device B and the main compression device P are arranged during the pre-compression and the main compression as shown in FIGS. 24 and 25. A mold supporting device E is provided. The mold supporting apparatus E will be described below.

The machine bases e1 and e1 'disposed on the sides of the belt conveyor V with the belt conveyor V interposed therebetween have concave grooves m3 formed in the outer wall of the supporting member m2 of the mold M described above.
Support plates e2 and e2 ′ having substantially semicircular recesses are provided at the tip end portion thereof that can be fitted to the. The support plates e2, e
Since the moving device for moving 2'is the same, a moving device for the support plate e2 provided on one machine base e1 will be described.

Reference numerals e3 and e4 denote guide blocks provided with grooves into which side portions of the support plate e2 provided on the machine base e1 are fitted, and e5 denotes the support plate e2 and the guide block. It is a piston rod of a cylinder (not shown) for moving along e3 and e4. Therefore,
By appropriately activating a cylinder (not shown) to move the piston rod e5 in the direction of the mold M, as shown by the solid line in FIG. The leading end portions of the support plates e2 and e2 ′ are fitted from both sides into the recessed groove m3, and the die M is supported by the support plate e.
2, e2 '. As described above, by supporting the mold M by the mold supporting device E in the preliminary compression process and the main compression process, the pressure applied to the belt conveyor V during the compression process by the preliminary compression device B and the main compression device P. It is possible to prevent the damage of the belt conveyor V by receiving the mold supporting device E.

After the pre-compression step and the main compression step by the pre-compression apparatus B and the main compression apparatus P are completed, a cylinder (not shown) is appropriately operated so that the piston rod e5 is opposite to the mold M. By moving the support plate e as shown by the chain double-dashed line in FIG.
2, the tip of e2 'is pulled out from the groove m3 formed in the outer wall of the supporting member m2 of the mold M, and the belt conveyor V
Is driven so that the mold M moves to the next process position.

Next to the main compression device P, a carrying-out device T for taking out the powder compact W from the rubber mold m1 as described above is arranged on the side of the belt conveyor V, and the rubber mold m1 is carried out by the carrying-out device T. Powder compact W taken out from
Is placed on the transfer device t12 and transferred to the next step such as sintering.

The mold M from which the green compact W has been taken out from the rubber mold m1 by the carry-out device T is the hand robot R1.
The hand robot R2 similar to the above returns it to a predetermined position on the rotary table h1 again, and then the above-mentioned cleaning device C performs the cleaning process of the rubber mold m1.

The mold M on which the cleaning step of the rubber mold m1 has been performed is removed from the mold M at the preliminary compression step position after the preliminary compression step by the preliminary compression apparatus B by the guide member transfer device D described above. The tubular guide member G is placed.

In this embodiment, the rotary table h1
Since the preliminary compression device B, the main compression device P, and the unloading device T are not provided on the machine base h2 around the table, but are arranged in a place adjacent to the rotary table h1, more powder is added. Since the supply device S can be arranged around the rotary table h1, more multi-layer green compact W can be formed. In addition, as in the above-described embodiment, each powder supply device S
1 to S3 are arranged on the rotary table h1 corresponding to each mold M, and the rubber mold m1 and the tubular guide member G of the same mold M are always provided from the respective powder supply devices S1 to S3. It can also be configured to supply a powder.

In the above-described embodiment of the present invention, the mold M is arranged on the rotary table h1 which rotates intermittently, and the powder supply devices S1 to S3 are arranged around the rotary table h1.
However, it is also possible to dispose the mold M linearly on the moving table and to arrange the powder supply devices S1 to S3 and the like on the side of the moving table. In addition, although an example in which the rubber mold m1 mounted on the mold M is filled with powder has been shown, the rubber mold m1 removed from the mold M is shown.
Alternatively, the rubber mold m1 filled with the powder may be mounted on the mold M after the powder is filled in 1, and then the main compression or the like may be performed.

The green compacts containing abrasive grains formed by the method of the present invention as described above include a single green powder compact and a multi-layer green compact formed by layering various kinds of mixed powders. , No cracks or chips. Then, these green compacts were put into a graphite mold and a pressure of 100 Kgf / cm ² or less was applied to 100
By performing pressure firing for 5 minutes to 1 hour at a temperature of up to 0 ° C., single-layer and multi-layered grindstones could be prepared. In this way, it was shown that a high-quality metal-bonded single-layer or multi-layered grindstone can be efficiently produced by using the method of the present invention. The method of the present invention can also be applied to resin-bonded and vitrified grindstones, and single-layer and multi-layered grindstones of each bonding type can be efficiently produced by calcination after powder compaction under normal pressure or pressure.

[0116]

Since the present invention is constructed as described above, it has the following effects.

Since the rubber mold is used to compress and mold the powder containing the abrasive grains, the conventional mold is one in which the abrasive grains wear the mold wall at the time of compression and at the time of taking out the green compact after compression. In addition to being able to solve the problems of the pressing method, in the method of the present invention, when the powder containing the abrasive grains is compressed and then unloaded, it is possible to press the powder compact without pushing up by the lower punch as in the conventional method. Can be taken out easily. Therefore, it is possible to carry out a cycle of powder filling, powder compacting, and powder compact removal with the lower punch attached to the die.

In the present invention, the upper punch does not have to be inserted into the mold at the time of compression, but it is sufficient to push down the entire mold. Therefore, the mold filled with the rubber mold is rotated or reciprocated. It is possible to easily realize an automated device capable of performing powder filling, powder compacting, powder compact removal and the like in a plurality of stages, and therefore, the productivity of powder compacting can be improved. Further, in such an automated device, since the upper punch, the press column and the like are not arranged in the stage before the main compression,
A precise powder weighing machine, a precision powder feeder, a powder leveling machine, etc. can be arranged in sequence. Therefore, powder containing expensive abrasive grains is precisely weighed, multi-layered, compressed and taken out, and a high-quality multi-layer green compact can be produced in a much shorter cycle time than the conventional die pressing method.

Since the compression is performed by pseudo-hydrostatic pressure using a rubber mold, the pressure distribution in the compressed green compact is uniform, and therefore cracking and chipping of the green compact can be prevented and the green compact can be prevented. Since there is no friction between the green compact and the inner surface of the rubber mold when the body is taken out of the rubber mold, the molded green compact is not distorted or damaged.

[Brief description of drawings]

FIG. 1 is a plan view of a disc-shaped cutting tool.

FIG. 2 is a perspective view of a green compact before being baked into a grindstone.

FIG. 3 is a vertical cross-sectional view of a metal mold or the like showing the sequence of forming steps of the green compact.

FIG. 4 is a front view of the unloading device including a partial cross-section that follows FIG.

FIG. 5 is a front view of the cleaning device including a partial cross section following FIG. 4 showing the sequence of forming steps of the green compact.

FIG. 6 is a perspective view of a mold, a tubular guide member, a compression plate, and the like.

FIG. 7 is a perspective view of a green compact molding apparatus to which the method of the present invention is applied.

FIG. 8 is a side sectional view taken along the center line of the mold.

FIG. 9 is a side sectional view taken along the center line of a mold of another embodiment.

FIG. 10 is a front view including a partial cross section of the powder supply apparatus.

FIG. 11 is a front view including a partial cross section of the powder supply device.

FIG. 12 is a front view including a partial cross section of another embodiment of the powder supply apparatus.

FIG. 13 is a front view including a partial cross section of still another embodiment of the powder supply device.

FIG. 14 is a partially enlarged front view of still another embodiment of the powder supply device.

FIG. 15 is a partially enlarged front view of a further embodiment of the powder supply device.

FIG. 16 is a front view of a preliminary compression device and a main compression device.

FIG. 17 is a front view including a partial cross-section of a die, an upper punch, and the like showing the sequence of the main compression process.

FIG. 18 is a front view including a partial cross section of a carry-out device for taking out the green compact from the rubber mold.

FIG. 19 is an enlarged sectional view of a main part of a suction member of the carry-out device.

FIG. 20 is a side view including a partial cross section of the cleaning device that cleans the rubber mold from which the green compact has been taken out.

FIG. 21 is a plan view of a cylindrical guide member transfer device.

FIG. 22 is a side view including a partial cross section of the tubular guide member transfer device.

FIG. 23 is a plan view of another embodiment of the green compact molding apparatus to which the method of the present invention is applied.

FIG. 24 is a plan view of a mold supporting device and the like.

25 is a side sectional view of the mold supporting device and the like taken along the line I-I of FIG. 24.

[Explanation of symbols]

 B: Preliminary compression device C: Cleaning device D: Cylindrical guide member transfer device G: Cylindrical guide member H:・ Powder compacting device M ・ ・ ・ ・ ・ ・ Mold P ・ ・ ・ ・ ・ ・ Main compression device S ・ ・ ・ ・ ・ ・ Powder supply device T ・ ・ ・ ・ ・ ・ Unloading device V ・ ・ ・ ・ ・・ Belt conveyor W ・ ・ ・ ・ Green compact Y ・ ・ ・ ・ Disc-shaped cutting tool

Claims (4)

[Claims] 1. A rubber mold mounted on a mold is filled with powder containing abrasive grains, and then the rubber mold is compressed between the mold and an upper punch placed on the mold. A method for molding a green compact containing abrasive grains, which comprises molding a green compact containing abrasive grains. 2. A rubber mold mounted on a mold is filled with abrasive-containing powder in layers in a stepwise or continuous manner, and then between the mold and an upper punch placed on the mold. 2. A method for molding a green compact containing abrasive grains, comprising compressing the rubber mold to form a green compact containing abrasive grains. 3. A green compact containing abrasive grains is formed by compressing the rubber mold between a die and an upper punch placed on the die to form a green compact containing abrasive grains. The method for molding a green compact containing abrasive grains according to claim 1 or 2, wherein the body is taken out and the rubber mold from which the green compact containing the abrasive grains is taken out is cleaned. 4. A powder containing abrasive grains is supplied to a rubber mold mounted on a mold and a cylindrical guide member mounted on the mold,
Next, by compressing the powder containing abrasive grains supplied to the rubber mold and the tubular guide member, the powder containing abrasive grains was filled into the rubber mold, and then placed on the mold and the mold. A method for molding a green compact containing abrasive grains, comprising molding a green compact containing abrasive grains by compressing a rubber mold with an upper punch.