JPH0639085B2 - Method and apparatus for manufacturing molded article having step - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to rotary powder compression for continuously producing molded articles such as electric parts and pharmaceuticals by compression molding powders which are raw materials such as ferrite and ceramics. Related to the molding machine,
More specifically, the present invention relates to a manufacturing method and an apparatus for manufacturing a molded product having a step in the rotary powder compression molding machine.

[Prior Art] Generally, a powder compression molded product has a cylindrical body, an ellipsoidal body, or a prismatic body, that is, the powder is filled in a cylindrical or rectangular cylindrical die hole, and the tips of both are flat. Although it is compression-molded by a pestle and a lower pestle, a molded product having a stepped shape which is not necessarily produced by a flat pestle is required depending on its application such as electric parts.

Therefore, conventionally, in a rotary powder compression molding machine in which powder is filled in a die hole of a mortar arranged on a rotary disk and compression molding is performed by an upper punch and a lower punch, the tip of the upper punch or the lower punch is punched. To the department
A molded product having a step is manufactured by forming a step portion that corresponds to the step required by the molded product and compressing it with a punch having the step portion.

[Problems to be Solved by the Invention] Although a molded article having a level difference can be obtained for some time even with this conventional technique, there is a problem that a crack is generated from a boundary between a portion having a high level difference and a portion having a low level difference. is there.

That is, the powder filled in the die hole is in a uniform state throughout the die hole, but when it is compression-molded, it is compressed by the protruding part of the punch tip (see FIGS. 3 and 4). Since the left side in the figure has a higher compression density than the opposite side that does not project, the density will be different on the left and right of the stepped part of the molded product, and a crack will occur easily from the boundary between them and it will be a defective product. Or even if no cracks occur, the compression density is extremely non-uniform, resulting in a defective product.

The present invention has been made in view of such problems of the conventional technology, and an object of the present invention is to provide a rotary powder compression molding machine suitable for mass production, in which the compression density of a molded product is more improved. An object of the present invention is to provide a manufacturing method and an apparatus for manufacturing the same that can be made uniform.

[Means for Solving the Problems] In order to achieve the above object, in the method for producing a molded article having a step according to the present invention, a large number of dies of a rotary disk are filled with powder, and at least one of the upper and lower punch tips is used. In a method for producing a molded article having a step formed by compression molding with an upper punch having a step and a lower punch, a part of the die is covered with the upper part of the die and the lower punch is raised, and the space between the lower punch and the cover is increased. The pre-compressed powder of No. 1 and the other part of the uncovered powder are discharged to the outside of the die, and before the main compression, the powder density in the die hole is changed with the step of the punch as the boundary to obtain the compressed density of the molded product. It is characterized by making uniform.

And, the apparatus for manufacturing a molded article having a step according to the present invention is such that a powder is filled in a die hole of a die provided in a large number on a rotary disk, and an upper punch having a step portion at least at one of the upper and lower punch tips is provided. In a device for manufacturing a molded article having a step obtained by compression molding with a lower punch, a pressing plate that covers a part of the upper surface of the die is provided between the powder filling step and the compression step,
It is characterized by disposing a lower punch lifting device for raising the lower punch by a required amount.

In the above structure, the pressing plate may be provided with a slide plate for scraping off the powder outside the die.

In this case, the accuracy of powder density is improved.

[Operation] As shown in FIG. 3, for example, the lower tip of the punch has a stepped portion,
When compressing the filling powder to a volume of 1/2, the powder is filled into the die hole having the bottom formed by the lower punch (step A).

At this time, since the ratio of the volume in the die hole to the state of the main compression (step D) can be easily discriminated by the upper punch and the lower punch, as indicated by the chain double-dashed line, from step A to step D If it were transferred directly, the upper powder with a low step without protruding of the lower punch could be compressed to a volume of 1/2 as desired, while the upper powder with a high step with protruding lower punch could be compressed by 3 minutes. Therefore, a compressed product having different compression densities is formed on the left and right sides of the compressed product.

Therefore, after the powder filling step A, the upper part of the upper surface of the die, which is a part of the lower punch with a low step where the step is not projected, is covered with a retainer plate, and the lower punch is in a desired amount (the same amount as the step). A pre-compression step B of raising is performed to pre-compress the powder between the lower punch and the pressing plate, and at the same time, a part of the upper powder with a high step where the lower punch protrudes is discharged out of the die hole.

As a result, the amount of powder in the die hole is twice as much as that of the upper part of the lower punch, which is not projected. Then, if desired, the powder is discharged in a more quantitative manner in a scraping step C in which a slide plate is arranged, and then the process proceeds to a main compression step D, where the original compression molding is performed by the upper and lower punches. If this is done, the volume of the powder will be halved over the entire molded product, and a product having a uniform compression density can be obtained.

Further, as shown in FIG. 4, when the tip portion of the upper punch has a stepped portion and is compressed to a volume of half in the same manner as above, after the powder filling step a, the punch with which the upper punch does not protrude is used. A preliminary compression step b is formed in which the upper surface of the die hole facing the tip is covered with a pressing plate and the lower punch is raised by about 1/4 of the powder filling height, and subsequently, the cutting step C and the main compression step d are performed.

At this time, the powder (the powder on the left side) in the die hole facing the protruding punch tip of the upper punch is discharged to the outside of the die punch by an amount corresponding to the rise of the lower punch, and at the same time, the die hole facing the punch tip of the upper punch which does not project. The powder inside (the powder on the right) has the same amount of powder and is pre-compressed.

That is, the right and left powder amounts are filled at a ratio of 3: 4, and if this is compressed as in the main compression step d, the left side is compressed to a third volume, while The right side is compressed to half the volume of the powder at the beginning of the head, and is significantly improved compared to the case without conventional pre-compression, to the extent that the difference in powder compression density on the left and right does not affect use. To be done.

In addition, in the actual compression molding, the tip of the upper punch protruding into the filling powder drops first, so that the powder on the left side is pushed to the right side to some extent, and in the theoretical case above. In comparison, the left and right powder compression densities are closer to each other and can be made uniform.

[Examples] Examples will be described with reference to the drawings.

In FIGS. 1 to 3, the mortars (2) are arranged at equal intervals on the peripheral portion of the rotating disk (1).

This die (2) is a punch tip having a step (4) of a lower punch (6) slidably inserted in a lower punch mounting plate (10) integrally formed with the rotating disc (1). The bottom part of the die hole that determines the filling amount of the powder (3) is formed.

The upper punch (5) is slidably inserted into an upper punch mounting plate (not shown) formed integrally with the rotary disc (1), and the tip of the punch is flat, and the upper punch (6) and the lower punch (6) are They are arranged to face each other.

The presser plate (7) is continuously arranged after the feed shoe (11) for filling the powder (3), and the die (6) above the lower punch tip of the step (4) of the lower punch (6). The structure is formed so as to cover only the upper surface of 2) and can withstand a certain amount of pressure from below.

The arrangement of the holding plate (7) does not necessarily have to coincide with the step (4), and in order to easily obtain the best position, the holding plate (7) is arranged horizontally in this embodiment. The movement is also adjustable.

The slide plate (8) is formed integrally with the pressing plate (7) continuously, and is formed on the upper surface of the die (2), that is, the upper surface of the rotating disk (1).
It is worn so as to move (3) to the center of the turntable (1).

The lower punch lifting device (9) separates the lower punch lifting rail (12) from the normal lower punch lifting rail (12), and when the die (2) matches the position of the holding plate (7), the lower punch (6) is moved by a desired amount. It is raised (in the present embodiment, the same amount as the step of the lower punch) and the amount of rise is adjustable.

And, (13) is a molded product, (14) is a powder charging port, and (15) is a lower punch.
(6) and the upper punch (5) pass through the compression roll for main compression molding, (16) is an ejector for guiding the molded product to the outside of the turntable,
(17) is a receiving can for storing the molded product, and (18) is a hit bar for changing the direction of the molded product, which is for changing the take-out direction of the molded product as desired, and is not necessarily provided.

In this operation, the powder (3) is quantitatively filled in the die in the powder filling step A, and the lower punch is raised in the pre-compression step B to pre-compress the powder on the right side and part of the powder on the left side. The powder is discharged to the outside, and then the discharged powder (3) is eliminated by the scraping step C, and the upper punch (5) and the lower punch are removed by the main compression step D.
Compressed by (6) and molded product by extraction process E (13)
Is taken out on the upper surface of the rotary disk (1) and outside the disk, and a series of steps during one rotation of the rotary disk (1) is completed.

FIG. 4 shows another embodiment of the present invention.
This is a case where the punch tip portion of (5) has a step portion (4) and is structurally substantially the same as the above-mentioned embodiment.

In this operation, the powder (3) is quantitatively filled in the die in the powder filling step a, the lower punch is raised in the precompression step b to precompress the right powder, and a part of the left powder is partially punched. The powder is discharged to the outside, and then the powder (3) discharged by the scraping step c is eliminated, and the upper punch (5) and the lower punch are punched by the main compression step d.
(6) is used for compression, and the molded product (13) is taken out of the rotary disk (1) by the take-out tool (16) in the take-out step e.

The present invention is not limited to the above embodiment, for example, the shape of the molded article having a step is such that a part of the columnar portion is projected, or only the central portion or the central portion is projected, Alternatively, it may have a plurality of steps having different heights, or may have steps on both upper and lower sides (in the case of having stepped portions on both upper and lower punch tips), which is arbitrary.

Further, in the case of a molded product having a plurality of steps having different heights, a plurality of presser plates may be provided and precompressed a plurality of times according to the presser plate. In the case of a molded product having a step height such that the height is low, a plurality of parts may be provided at one location and precompression may be performed once.

EFFECTS OF THE INVENTION As described above, the present invention provides a molded product having a more uniform powder compression density step in a device capable of mass production such as a rotary powder compression molding machine and having a simple structure. Since it can be obtained, it is possible to provide a large amount of the product at low cost, and it is possible to provide a product in which no crack is generated from the step portion or the like.

Further, since the compression density of the entire molded product is made uniform, the performance such as weight, strength and electrical characteristics is stably improved, and the molded product accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a plan view of an essential part showing an embodiment of the present invention, FIG. 2 is an expanded longitudinal sectional view of an expanded essential part vertically cut at the center of each die, and FIG. 3 is a process diagram similarly illustrating the operation of the essential part. FIG. 4 is a process drawing showing another embodiment of the present invention. 1 ... Rotating disk, 2 ... Mill, 3 ... Powder, 4 ... Step, 5
…… Upper punch, 6 …… Lower punch, 7 …… Presser plate, 8 …… Sliding plate,
9 ... Lower punch lifting device, 10 ... Lower punch mounting board, 11 ... Feed shoe, 12 ... Lower punch lifting rail, 13 ... Molded product, 14 ...
… Powder charging port, 15 …… compressing roll, 16 …… extractor, 17…
… Cans, 18 …… Hit sticks

Claims (3)

[Claims] 1. A method for producing a molded article having a step, in which a large number of dies of a rotary disk are filled with powder, and compression molding is performed by an upper punch and a lower punch having at least one of the upper and lower punch tips with a step. A part of the die is covered with the upper part of the die and the lower punch is raised to pre-compress the powder between the lower punch and the cover while discharging a part of the other uncovered powder to the outside of the die. A method for producing a molded article having a step, characterized in that the compressed density of the molded article is made uniform by previously changing the powder density in the die hole across the step portion of the punch. 2. A powdered powder (3) is filled in a die hole of a die (2) arranged in a large number on a rotary disc (1), and at least one of the upper and lower punches has a stepped portion (4). In a device for manufacturing a molded article having a step obtained by compression molding with a punch (5) and a lower punch (6),
Between the powder filling step and the compression step, a pressing plate (7) covering a part of the upper surface of the die (2) is arranged, and a lower punch lifting device (9) for raising the lower punch (6) by a desired amount. ) Is provided, the apparatus for manufacturing a molded article having a step. 3. The step according to claim 2, wherein the holding plate (7) is provided with a sliding plate (8) for scraping off the powder (3) outside the die (2). Equipment for manufacturing molded products.