JPH10314995A - Compacting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compacting device capable of obtaining a green compact having reduced density variance and a high dimensional precision product. SOLUTION: The compacting device is constructed with an upper punch, a lower punch 3, a die 4, a hopper, a feeder cup 1 and a powder supply piping, a partition plate 6 having an orifice of 1.0-10 mm diameter is arranged at a powder introducing port to the feeder cup 1 in the powder supply piping 7, further, a partition plate 8 having an orifice of 1.0-3.0 mm diameter is arranged in the feeder cup 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder molding apparatus and, more particularly, to a structure of a powder supply section including a feeder cup and a powder supply pipe.

[0002]

2. Description of the Related Art Generally, when a green compact is formed using a powder forming apparatus, the powder is fed by gravity through a powder supply pipe 7 connecting a hopper 9 and a feeder cup 1 as shown in FIG. It is dropped into the cup 1 and is always supplied in the supply state. That is, the hopper 9
However, when the powder is supplied to the powder filling section 2 at the center of the die 4, the powder in the hopper 9 and the powder in the powder filling section 2 are in a connected state.

[0003] For this reason, depending on the remaining amount of storage in the hopper 9,
The pressure in the pipe 7 and the powder filling unit 2 changes, and the bulk density of the powder in the powder filling unit 2 changes. As a result, there is a problem that the powder filling amount of the powder filling section 2 changes, the density of the green compact formed in this state changes, and the dimensional variation of the sintered body increases.

[0004] In particular, when compact parts requiring dimensional accuracy are molded at high speed, fluctuations in the bulk density of the powder in the powder filling section greatly affect the density of the green compact, and the dimensional accuracy of the product is maintained. There was a problem that it could not.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a powder compact having a powder supply section capable of obtaining a compact having a small variation in density and obtaining a product having high dimensional accuracy. To provide the device.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a powder molding apparatus having an upper punch, a lower punch, a die, a hopper, a feeder cup, and a powder supply pipe as a basic structure. A partition plate having an orifice having a diameter of 1.0 to 10 mm was provided at the powder inlet to the cup, and a partition plate having an orifice having a diameter of 1.0 to 3.0 mm was provided inside the feeder cup. It is a powder molding apparatus characterized by the above-mentioned.

[0007] The inside of a powder supply pipe provided above the upper surface of the feeder cup of the powder supply section of the powder molding apparatus,
A diameter of 1.0 to 10 is set at the powder inlet to the feeder cup.
By providing a partition plate having an orifice of 1 mm and passing the powder supplied from the hopper through the orifice, the pressure of the powder in the hopper and the powder supply pipe into the feeder cup is reduced.

Further, the inside of the feeder cup is vertically divided by a partition plate having at least one orifice having a diameter of 1.0 to 3.0 mm, and the powder is dropped through the orifice of the partition plate to fill the powder filling portion of the die. By doing so, the pressure of the powder below the partition plate becomes constant, and the bulk density of the powder immediately before filling into the die becomes constant. As a result, the filling amount of the powder in the die becomes constant, and the dimensional variation is reduced.

[0009] In general, in dry molding, in order to improve the flowability of the powder, the crushed particles are reduced to 50 to 400 µm.
Granulation is performed to a degree. In the present invention, the diameter of the orifice provided on the partition plate in the powder supply pipe is 1.0 to 10 mm, and the diameter of the orifice provided on the partition plate inside the feeder cup is 1.0 to 3.0 mm. The reason is that if the diameter is smaller than the lower limit value, the fluidity when the powder passes through the orifice decreases, the supply amount of the powder decreases, and stable pressing cannot be performed. If the supply amount is small, there is a risk that the mold is damaged. On the other hand, if the diameter is larger than the upper limit, the effect of relaxing the powder pressure on the feeder cup is reduced.

According to the present invention, by adopting the above structure, the powder can be supplied in a state where the bulk density of the powder in the powder filling portion, particularly the portion below the partition plate where the powder falls into the die, is kept constant. Since it is not affected by the remaining amount of the powder, the variation in the density of the green compact can be reduced.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An orifice having a diameter of 1.0 to 10 mm is provided at a powder supply port to a feeder cup inside a powder supply pipe, and a 1.0 to 3.0 mm diameter orifice is further provided inside the feeder cup. A partition plate having one or more orifices is provided.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a configuration of a powder supply section of a powder molding apparatus according to one embodiment of the present invention.

As shown in FIG. 1, a partition plate having an orifice of an arbitrary diameter is provided at a powder inlet of a pipe 7 provided on an upper surface of a feeder cup 1 in a powder supply unit of a powder molding apparatus of the present embodiment. 6 are provided. In this embodiment, the diameter of the orifice is 0.5, 1.0, 5.0, 10, 15 m.
m of the five types of partition plates 6 were used.

The inside of the feeder cup 1 is vertically divided by a partition plate 8 having an orifice of an arbitrary diameter. In this embodiment, the diameter of the orifice is 0.5,
Five types of partition plates 8 having a size of 1.0, 2.0, 3.0, and 4.0 mm were used. The partition plate 8 was manufactured such that the total area of the holes in the orifice was about 5 cm ² .

Using the above-mentioned apparatus, the outer dimensions are 10 mm × 5 m.
m, 1,000 mm square soft ferrite cores having a height of 3 mm and a thickness of 1 mm were formed. In addition, as a comparative example, molding was similarly performed using a conventional apparatus. The σ (standard deviation) of the height of these compacts was determined. Table 1 shows the results.
Shown in

[0016]

[Table 1]

According to Table 1, in the comparative example, the height dimension σ is 0.140 (mm), while in the present embodiment, the diameter of the orifice in the powder supply pipe is 1.0 to 10 mm,
Further, when the diameter of the orifice of the partition plate is 1.0 to 3.0 mm, it can be seen that the dimensional variation can be suppressed as compared with the comparative example.

[0018]

As described above, the partitioning plate having an orifice of 1.0 to 10.0 mm is attached to the inside of the powder supply pipe above the upper surface of the feeder cup by the powder molding apparatus of the present invention. 1.0-3.0m
By partitioning vertically with a partition plate having an m orifice, the bulk density of the powder in the powder filling section at the center of the die can be kept constant, suppressing the variation in the density of the compact and suppressing the variation in the product dimensions. I was able to.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a powder supply unit of a powder molding apparatus according to one embodiment of the present invention.

FIG. 2 is a sectional view showing the overall configuration of a conventional powder molding apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Feeder cup 2 Powder filling part 3 Lower punch 4 Die 5 Base 6, 8 Partition plate 7 (Powder supply) piping 9 Hopper

Claims (1)

[Claims] In a powder molding apparatus having an upper punch, a lower punch, a die, a hopper, a feeder cup, and a powder supply pipe as a basic configuration, a powder introduction port to the feeder cup in the powder supply pipe is provided. 1.0-10m in diameter
A powder forming apparatus, comprising: a partition plate having an m orifice; and a partition plate having an orifice having a diameter of 1.0 to 3.0 mm inside the feeder cup.