JPH06142994A - Method and device for compacting powder by using rubber mold - Google Patents

Abstract

PURPOSE:To miniaturize a device and to reduce equipment cost by transmitting the force of an upper punch to a supporting stand through a rotary table. CONSTITUTION:Powder is filled in a cavity member 2b of a rubber mold attached on a die 2 of a die press machine. The rubber mold and the powder are compressed by lowering an upper punch 3a. A compacting is taken out. These processes are executed by repeating on a circulating route while rotating a rubber mold conveying rotary table 32. Then, the force generating by lowering the upper punch 3a is transmitted to a supporting stand 50 abutted on a lower part of the rotary table or arranged remarkably nearby the lower side through the rotary table 32. The force of the upper punch is transmitted to the supporting stand 50 of the lower side of the rotary table through the lower punch 3b engaged with the rotary table 32 so that a hole part of the rotary table is movable up and down. Therefore, the aberration of the precision is made less, and the efficiency can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a rubber mold to press powders of permanent magnets, soft magnetic materials, structural materials, electric materials, tool materials, automobile parts, etc., under pressure by a punch of a die press machine and rubber. A method for producing a powder compact by compressing using deformation force (hereinafter referred to as "rubber mold die press method").
,) And improvement of the device.

[0002]

2. Description of the Related Art According to Japanese Patent Publication No. 55-26601, a preformed rubber container is placed in a mold, rare earth cobalt alloy powder is placed in the rubber container, and parallel die pressing is performed to make the rubber container a pressure medium. A rubber mold die press method has been disclosed in which the magnetic property is improved to the same level as in the vertical die press by using the above.

Further, the present applicant has found that European Patent Publication No. 0
In 488334 (published on June 3, 1999),
We proposed a rubber mold die press method that has some of the following features. (1) A rubber mold is filled with fine powder other than permanent magnet powder and permanent magnet powder such as titanium at a high density to prevent cracking and chipping of the green compact. (2) High-density filling of the powder into the rubber mold, die pressing, and removal of the green compact from the rubber mold are performed in the circulation path for conveying the rubber mold. (3) A rubber mold in which at least one of the upper and lower sides of the rubber mold facing the upper and lower punches of the die press machine is harder than the rubber of the side portion where the rubber mold faces the die of the die press machine. (4) The powder is filled by fixing a guide frame to the upper part of the rubber mold, raising the powder into the latter, and then pressing with a pusher. (5) A method of performing orientation in a magnetic field by a pulsed magnetic field. (6) A method in which a pulsed magnetic field is applied to the powder outside the die press machine and magnetic fieldless compression is performed inside the die press machine. (7) The upper and lower punches are used in the circular path type rubber mold die press method of the above (2). In this method, the lower punch is divided into upper and lower parts, the upper part is a movable die bottom that is always fitted in the die, and the lower part is hydraulically operated. The upper part also has the role of pushing the rubber mold after compression out of the die. (8) The upper lid of the rubber mold is made of hard rubber or metal.

In order to use the rubber mold die press method for mass production, the inventors of the present invention have carried out processes such as powder filling into a rubber mold, molding, and unloading at different locations of the circulation path as a method of shortening the cycle time. It was proposed to do it at the (stage) (see (2) above).

When carrying out the rubber mold die press method using the circulation path, the rotary table is stopped at a predetermined position for a certain period of time, work such as powder filling is performed, and after the work is completed, the rotation is restarted to perform these operations. Do it continuously. As the rotary table having the above-mentioned structure and capable of operating, an index table which has been mainly used for indexing a machining center or for an automatic assembling lie is preferable.

When the upper and lower punches which are hydraulically, pneumatically and mechanically driven by the method (7) of the prior art are used, it is necessary to align the upper and lower punches with the die cavity. Since there is no room in the space for installing the lower punch since the motor etc. are arranged, it is preferable not to use the hydraulic, pneumatic, mechanically driven lower punch when using the rotary table. Also, by omitting the hydraulically driven punch, the driving force can be cut in half, making the entire equipment lightweight and compact.
It becomes low price.

[0007]

If the rotary table such as the index table is made to be strong enough to withstand the pressure of the press applied from the punch of the die press machine through the rubber mold, the thickness of the rotary table becomes large and the entire apparatus becomes large. Furthermore, since pressure is transmitted from the rotary table to the rotary shaft, the rotary shaft bends and becomes eccentric, which makes it difficult to align the rotary table with each processing position. Therefore, it is an object of the present invention to solve these problems in a rubber mold die pressing method and apparatus that uses a circulating path method using a rotary table.

[0008]

The first aspect of the present invention is to fill a cavity of a rubber mold loaded in a die of a die press machine with powder, and compress the rubber mold and powder by lowering a punch on the press machine. In the powder compaction molding method in which each step of taking out the compacted powder compact is sequentially repeated in a circular path while rotating the rotary table that conveys the rubber mold, the force generated by the lowering of the upper punch is applied to the rotary table. A powder compaction molding method using a rubber mold, which is characterized by transmitting to a support table arranged in close proximity to or in contact with the lower part of the rotary table through, and for carrying out this method, Place the powder in the cavity of the rubber mold, compress the rubber mold and powder with a die press machine punch, and take out the powder compact In a powder compacting apparatus using a rubber mold provided with a rotary table for transporting a mold, a support base is provided at a compression position of the powder with or without a minute gap below the die. The present invention relates to a powder compacting device using a rubber mold. A pressurizing means such as a hydraulic cylinder and a spring may be provided at a predetermined position below the rotary table, but the simplest configuration is to provide the support base as described above.

The second aspect of the present invention is to fill the cavity of the rubber mold loaded in the die of the die press machine with the powder, compress the rubber mold and powder by lowering the punch on the press machine, and press the powder compact. In a powder compaction molding method in which each of the steps of taking out is sequentially repeated in a circulating path while rotating a rotary table that conveys the rubber mold, the force generated by the lowering of the upper punch is used to move the holes of the rotary table up and down. A powder compacting method using a rubber mold, characterized in that it conveys to a support base under the rotary table via a lower punch which is possibly engaged with the rotary table, and for carrying out this method, Fill the cavity of the rubber mold with powder, press the rubber mold and punch with a die press machine to compress the powder, and remove the powder compact from the respective positions. In a powder compacting apparatus using a rubber mold provided with a rotary table for transporting a mold, a lower punch that vertically penetrates a hole provided in the rotary table at a compression position of the powder, and a lower punch. Powder for use in a rubber mold, characterized in that it comprises means for engaging and supporting the punch with the rotary table and a support table provided below the lower punch with or without a minute gap. Powder compacting equipment.

The support table, which is a feature of the present invention, may be in contact with the rotary table so as to enable rotation of the rotary table, or an interval such that the rotary table does not cause harmful permanent deformation. They may be separated by an interval of about mm, and do not hinder the rotation of the rotary table in the conveying stage and prevent the rotary table from being bent by the upper punch in the compressing stage. The rotary table may have a die cavity formed therein, or the die may be detachable. The lower punch may be fixed to the rotary table.

In the present invention, “rubber mold”, “punch”, “die press machine”, “circulating path” are as defined and / or specifically exemplified in the above-mentioned European Patent Publication of the applicant. is there.

[0012]

According to the present invention, when a rubber mold die press method, which is a type of die press, is carried out using a rotary table such as an index table, it is found that the alignment accuracy of the index table is affected, and the burden is imposed on the index table. The power of the lower punch was transmitted to the support of the index table so that it would not be overwhelmed. That is, in the first aspect of the present invention, a hole is formed in the index table so that the force of the punch is directly applied to the support table so as not to cause the bending of the index table, and in the second aspect, the bending is performed in the vicinity of the index table. A support base is provided to prevent the above. Hereinafter, the present invention will be described with reference to examples.

[0013]

FIG. 1 is a diagram showing an embodiment of the present invention. In the figure, the die 2, the upper punch 3a, the air cylinder 5, the cylinder rod 6, and the support base 52 of the entire apparatus are all common in a die press machine. The coil 4 is also known in the magnetic field orientation press, and one of its functions has been described in the prior art (5). However, the upper punch 3a is a die 2 which is a feature of the invention filed separately by the applicant.
It is different from the general one in that it has a structure that pushes. Similarly, the coil 4 is lifted together with the upper punch 3a after the orientation in the magnetic field is finished so as not to interfere with the operation of rotating the die 2 together with the index table 32.

The index table 32 is for powder filling,
The rubber mold is sequentially conveyed to each work position such as taking out the powder compact, and is fixed to the rotary shaft 42. One end of the rotary shaft 42 is rotatably supported by the frame of the die press machine, and the other end is connected to a drive mechanism housed in the index table box 39.

The index table 32 has a lower punch 3
6 is fixed via a connecting plate 46, and a spring 3 is provided between the connecting plate 46 and a groove dug in the bottom of the die 2.
It is set so that 0 does not move horizontally but moves only up and down. Therefore, when the upper punch 3a descends, the die 2 descends, and the rubber mold (not shown) and powder in the die cavity 2b are compressed. During these operations, the die 2 gradually approaches the index table 32 while decreasing the descending amount, but finally the index table 3
No. 2 cannot withstand the pressure of the upper punch 3a and bends downward. Then, the support table 50 becomes the index table 32.
Support and prevent its bending. Subsequently, when the upper punch 3a further applies a pressure, the die 2 resists the force of the spring 30 to further compress the powder, and the powder is made into a compact. After the compaction is completed, the upper punch 3a rises, and the spring 30
Raises die 2 back to its original position.

FIG. 2 is a diagram illustrating another embodiment in which the same members as those in FIG. 1 are designated by the same reference numerals. The main difference between the embodiment of FIG. 2 and FIG. 1 is the structure of the upper punch and the engagement support mechanism by the spring of the lower punch. That is, the lower punch 3b is engaged with the index table by the springs 30a and 30b provided above and below the index table 32. Since the spring 30a is designed to have a stronger force than the spring 30b, the spring 30a absorbs most of the punching force after the start of compression and the punch 30b tends to extend. Reference numeral 33 is a jig for fixing the spring 30 to the index table 32 in the horizontal direction, and 34 is a bolt for fixing the lower punch 3b to the backup ring jig 37.

The rubber mold 10 is supported from below by a backup ring 36 made of hard rubber.
Prevents the rubber from getting caught.

FIG. 3 shows some structures of the rubber mold which can be used in the present invention. (A) is an integrated bottomed mold,
(B) shows a combination mold with a bottom 10k which may be made of hard rubber, and (c) shows a bottomless mold in which the lower punch 3b also serves as a bottom.

[0019]

Since the present invention is configured as described above, in the rubber mold die press method, when the rotary table is stopped at each work position and aligned with a predetermined mechanism or jig. Accuracy is reduced,
The efficiency can be improved, and in the rubber mold die press device, the device can be downsized and the equipment cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a die press machine for carrying out the method of the present invention.

FIG. 2 is a diagram showing another embodiment of a die press machine for carrying out the method of the present invention.

FIG. 3 is a diagram showing a structural example of a rubber mold.

[Explanation of symbols]

 2 Die 3a Upper punch 3b Lower punch 4 Coil 10 Rubber mold 30 Spring 32 Index table 37 Backup ring 50 Support stand

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Itaya 1 Ely Part 2 No. 401, Intermetalix Co., Ltd. 22-22 Matsumuro Ouegami-cho, Nishikyo-ku, Kyoto City, Kyoto Prefecture

Claims (6)

[Claims] 1. A method for filling powder into a cavity of a rubber mold loaded in a die of a die press machine, compressing the rubber mold and powder by lowering a punch on the press machine,
In the powder compacting method in which each step of taking out the compacted body is sequentially repeated in a circular path while rotating the rotary table that conveys the rubber mold, the force generated by the lowering of the upper punch is applied to the rotary table. A powder compaction molding method using a rubber mold, characterized in that the powder is transmitted to a support table arranged in contact with the lower part of the rotary table or in the immediate vicinity thereof. 2. A method of filling powder into a cavity of a rubber mold loaded in a die of a die press machine, compressing the rubber mold and powder by lowering a punch on the press machine,
In the powder compacting method in which each step of taking out the compacted body is sequentially repeated in a circulating path while rotating the rotary table that conveys the rubber mold, the force generated by the lowering of the upper punch is set to the rotary table. The method of powder compaction molding using a rubber mold, characterized in that the hole portion is transmitted to a support table below the rotary table via a lower punch engaged with the rotary table so as to be vertically movable. 3. The powder compacting method using a rubber mold according to claim 1, wherein the rotary table is an index table. 4. A rubber provided with a rotary table for transporting the rubber mold to each position of filling the cavity of the rubber mold with powder, compressing the rubber mold and powder with a punch of a die press machine, and taking out the powder compact. In a powder compacting apparatus using a mold, a lower punch that vertically penetrates a hole provided in the rotary table at a compression position of the powder, and means for engaging and supporting the lower punch with the rotary table. And a support base provided with or without a minute space below the lower punch, and a powder compacting apparatus for powder using a rubber mold. 5. A rubber provided with a rotary table for conveying the rubber mold to each position of filling the cavity portion of the rubber mold with the powder, compressing the rubber mold and the powder with a punch of a die press machine, and taking out the powder compact. In a powder compacting apparatus using a mold, a lower punch that vertically penetrates a hole provided in the rotary table at a position where the powder is compressed, and a means for engaging and supporting the lower punch with the rotary table. And a support base provided below the lower punch with or without a minute gap, and a powder compacting apparatus for powder using a rubber mold. 6. The powder compacting apparatus using a rubber mold according to claim 4, wherein the rotary table is an index table.