JP2005246441A - Powder vessel for powder molding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve rapid and smooth filling of powders into a cavity for a powder molding die, prevention of segregation, uniformity of filling by improving the flow of the powder in the powder vessel, such as a powder hopper or powder feeder. <P>SOLUTION: A vitreous component is imparted to a wall surface in contact with the powder of the powder vessel or a wall surface of an attachment member, such as a powder flow dividing plate, partition plate, vent pipe or exhaust pipe. The vitreous component is transparent glass of soda glass, borosilicate glass, solder glass, enamel, cloisonne, and the like. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a powder container such as a powder feeder or a powder hopper for filling powder in a die cavity of a powder molding apparatus using a mold when a sintered product is manufactured.

The mixed powder supplied to the powder molding machine is stored in a powder hopper with a funnel-shaped discharge port at the bottom, and is guided from the discharge port to a powder feeder that advances and retreats on the die table of the molding die. When the feeder advances, the mixed powder in the powder feeder is filled into the die cavity. Such powder containers such as hoppers and feeders are formed of carbon steel plates or stainless steel plates.
Examples of the powder hopper include a hollow inside, and a powder hopper provided with a ventilation pipe in the hopper as described in Patent Document 1 below. On the other hand, the powder feeder has a box shape with a lower opening and a powder feed opening at the upper part, for example, a plurality of partition plates attached in a feeder box as described in Non-Patent Document 1 below. It has a structure partitioned in the longitudinal direction, and when the feeder advances and retreats, it prevents the non-uniform filling due to powder bias, or from the inside of the box of the powder feeder as described in Patent Document 2 below There is a structure in which an exhaust pipe is provided outside and the powder filling property is improved by smoothly discharging the air in the die cavity during powder filling.

Japanese Patent Laid-Open No. 9-301486 JP 11-245092 A Powder Metallurgy Course 4 “Metal Powder Molding” (Nikkan Kogyo Shimbun, August 25, 1939), page 139, Fig. 3.40 (c)

These conventional powder containers such as powder hoppers and powder feeders have the following problems.
In the case of a hopper, the angle of the funnel and the size of the discharge port are limited because the powder in the container tends to stagnate the flow of the powder near the inner wall of the container. In addition, the powder having poor fluidity may not be able to cope with the desired powder discharge only by adjusting the angle and the discharge port diameter. The powder feeder needs to have a size that does not hinder powder flow even when the die cavity diameter is small. In particular, the fluidity of the powder in the container and the filling of the powder into the die cavity by means of plates and pipes attached in the container for the purpose of improving the fluidity of the powder in the powder container, preventing the segregation of the powder, and preventing the uneven filling of the powder. Phenomena that worsen sex may be observed.

  In order to solve such a problem, the present invention is characterized in that the wall surface in contact with the powder of the powder container, or the wall surface of an attached member such as a powder distribution plate, a partition plate, a vent pipe, and an exhaust pipe is made of glass. To do. The glassy material is any one of soda glass through glass, borosilicate glass, solder glass, enamel, and cloisonne. They are structured in consideration of ease of manufacture and strength, etc., but a glassy simple substance, a structure in which the outside of a glassy member is reinforced with resin or metal, at least a surface of the metal member in contact with the powder, for example A structure in which enamel is baked is an embodiment.

  Put a predetermined weight of atomized iron powder for powder metallurgy (trade name: Atmel 300M, manufactured by Kobe Steel Co., Ltd.) on each of the polished iron plate, acrylic resin plate, and plain glass plate, and tilt each plate. Comparing the minimum angle (slip angle) at which most of the iron powder slides, the iron plate is about 42 °, the resin plate is about 40 °, and the glass plate is about 35 °. The friction with the powder is less glass than the iron plate and the sliding is good, and the state when the powder flows under its own weight becomes good. For example, when a plurality of partition plates are attached to the powder feeder to improve powder segregation and powder filling properties, the gap between the partition plates can be set narrower. As a result, the quality of the sintered product can be improved.

Hereinafter, the powder container of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing an embodiment of a powder feeder. The feeder 1 waits in the right direction in the figure by an actuator (not shown) when powder is not filled, and moves to a die cavity 9c formed by a die 9a and a lower punch 9b as shown in the figure when filling. The inside powder 10 is filled into the die cavity 9c, and the filling powder is scraped off in the process of retreating to finish filling a predetermined amount.
Generally, when filling powder from a feeder, the powder is stored in a hopper and supplied to the feeder. In such a case, the powder is stored in a hopper 5 as shown in FIG. 1 is supplied under its own weight. The feeder 1 has a powder supply port in the box 2 that is open at the bottom. In this example, the feeder 1 is provided with a plurality of partition plates 4 orthogonal to the advancing and retreating directions to suppress segregation by suppressing the movement of powder due to shaking. At the same time, a slit is formed between the partition plates 4 to subdivide the filling into the die cavity 9c, thereby enabling more uniform filling.

  In the example of the feeder of the present invention, a transparent glass inner wall 3 is fixed inside the box 2 with a resin adhesive. Moreover, the partition plate 4 is made of through glass instead of iron, and its end is fixed to the side wall and the inner wall 3 of the box 2 with a resin adhesive. According to such a configuration, the friction between the partition plate 4 and the powder is reduced, and the powder in the vicinity of the partition plate 4 easily flows and falls following the flow and fall of the powder itself, so that the powder is satisfactorily filled. . In the case of using iron-based material powder, in the case of the feeder 1 made of iron plate, if the feeder 1 is magnetized, the flow of the powder may be inhibited. Eliminated. In particular, the effect appears in powder filling when the particle size of the powder is fine and the powder fluidity is inferior. Further, since the friction between the partition plate 4 and the powder is small, the interval between the partition plates 4 can be narrowed, the number of the partition plates 4 can be increased, and the slit width can be reduced. As a result, more powder filling can be achieved. Since it is performed through the slit, powder filling with less bias can be performed.

  The glass plate 3a of the inner wall 3 also has an effect of smoothing the powder movement in the vicinity of the inner wall 3 of the feeder 1, and the effect is remarkable in the case of a small feeder without the partition plate 4. In addition, in the case of a feeder with a built-in ventilation pipe mentioned in the background art section, the pipe itself is made of glass, or the surface of the pipe made of iron or the like is coated with a glassy substance to move the powder in the feeder. Can be made smooth. In the above embodiment, the glass plate is fixed with an adhesive. However, the same effect can be obtained by applying glass frit to the main part of a conventional iron feeder and heating and melting it to form a enamel coating.

  Next, FIG. 2 is a longitudinal sectional view of an embodiment of the powder hopper 5 for storing the powder to be supplied to the powder feeder 1. The lower part of the hopper 5 is a funnel-shaped tank, and a butterfly valve 8 is provided at the lower discharge port. Attach the wheels so that they can be transported. In an embodiment of the present invention, a hollow lining is provided on the inner side of a can body 6 of a conventional iron tank. When powder is put into the powder hopper 5 and the butterfly valve 8 is opened, the powder in the hopper is discharged preferentially near the center, and the drop flow is delayed by friction with the wall surface in the vicinity of the cylindrical portion and the funnel-shaped portion. When the inner wall surface is glassy, the powder flow near the wall surface is smoothly performed so as to follow the powder flow, and particularly when mixed powder is used, there is an effect that segregation of components and particle size is reduced.

In addition, the aspect of the said Example shows only one specific example, The structure is not limited to what was described in the said Example. For example, the same effect can be expected in a powder container to which a flow dividing plate similar to a partition plate or a ventilation pipe or an exhaust pipe is added.
Furthermore, the feeder and the hopper do not necessarily need to be used in combination as in the above-described embodiment. Depending on the properties of the raw material powder used, the feeder and the hopper of the present invention can be used alone or the feeder of the present invention and the conventional hopper, respectively. The conventional feeder and the hopper of the present invention can also be used in combination.

It is a longitudinal cross-sectional view of one embodiment of the powder feeder of this invention. It is a longitudinal cross-sectional view of one embodiment of the powder hopper of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Feeder 2 Box 3 Inner wall 3a Glass plate 4 Partition plate 5 Hopper 6 Can body 7 Lining 8 Butterfly valve 9a Die 9b Lower punch 9c Die cavity 10 Powder

Claims (5)

  A powder container for a powder molding apparatus, characterized in that a powder container to be filled in a die cavity of a mold for producing a green compact is made of a glassy wall surface in contact with the powder.   The powder container for a powder molding apparatus according to claim 1, wherein at least one of the wall surfaces of the inner wall of the powder container, the powder distribution plate, the partition plate, the vent pipe, and the exhaust pipe is made of glass.   3. The powder container for a powder molding apparatus according to claim 1, wherein the vitreous material is one of through glass of soda glass, borosilicate glass, solder glass, enamel, and cloisonne.   The powder container for a powder molding apparatus according to any one of claims 1 to 3, wherein the powder container is a hopper having a funnel-type powder discharge portion. The powder container for a powder molding apparatus according to any one of claims 1 to 3, wherein the powder container is a powder feeder for filling powder into a die cavity of a compacting mold.

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