JPS5846522B2 - How to get the best results - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the creation of a continuous molding method for long green compacts, and aims to provide a new molding method that can continuously mold long green compacts using simple and compact equipment. That is.

Methods for forming rod-shaped bodies by applying pressure to powder include the mold press method, in which the powder is charged into a mold and pressurized with a punch, and the powder is filled in a rubber bag and high pressure is applied using hydraulic pressure from the outer periphery of the bag. A hydrostatic method is known, and a method is known in which a wedge mold called an iris die is combined, a space formed in the center is contracted by the movement of the mold, and the powder filled in the space is press-molded. There is.

However, in all of these methods, the length of the rod-shaped object that can be molded is limited due to the equipment structure and the molding method in which the material is filled into the mold in a batchwise manner and pressure is applied to open the mold to remove the product. There is a fatal drawback in that it is not possible to continuously mold a long green compact to an arbitrary length due to restrictions.

Moreover, when molding long objects using the mold press method or the hydrostatic method, the equipment is extremely dog-shaped and complicated, resulting in high equipment and operating costs. This method had poor workability in terms of product removal and other aspects, and also had problems with product accuracy.

For these reasons, the inventors of the present invention have already filed a patent application in 1973-3.
No. 7947, Japanese Patent Application Laid-Open No. 48-103407,
We have developed a method of compressing powder in the radial direction by packing powder into a pipe and swaging it to reduce the internal volume of the pipe.

According to this method, it is possible to mold a fairly long length of powder because it is possible to mold only the length of the pipe, but it requires a pipe for covering, and it is difficult to fill it with powder and after molding. Workability is not very good, such as requiring a peeling process, and there are disadvantages in that the products that can be molded are limited to those with a circular cross section.In addition, the precision of the outer circumference of the molded product is poor, and the reaction between the coated pipe and the powder occurs during sintering. This method has some disadvantages, such as the fact that it tends to cause deterioration in quality.

The present invention was developed through research in order to eliminate the disadvantages and drawbacks of the conventional methods as described above, and allows continuous molding of long green compacts of arbitrary length with good workability using a simple and compact device. The purpose is to

One feature of the present invention is that four dice, each of which has two adjacent side surfaces inclined in opposite directions with respect to the die axis, are arranged in a horizontal frame such that the two side surfaces touch each other, and The dies are repeatedly reciprocated while continuously supplying powder into the gap between the dies by gravity or a feeding member,
The powder is compacted in fixed quantities on the inclined side surface of the die and continuously formed into a long body of arbitrary length.

Another feature of the invention is that within the horizontal frame.

Three or more dies whose two adjacent sides are inclined in opposite directions with respect to the die axis are arranged so that the inclined surfaces touch each other, and a conical cavity and a columnar cavity are formed in the center in the height direction. A continuous cavity is formed in the cylindrical cavity, and a drive mechanism is provided on the back of each die, and a means for continuously supplying powder to the conical cavity is provided, and a delivery port for the compact is provided at the bottom of the cylindrical cavity. This is because we have established

The embodiments of the present invention will be explained below with reference to the accompanying drawings. Figures 1 to 3 show an outline of the molding method of the present invention, and Figures 4 and 5 show a molding method for carrying out the method of the present invention. An example of a machine is shown below.

The mold according to the invention therefore consists of four molding dies 1,1°1.1 and a ring-shaped horizontal frame 2 surrounding the molding dies 1,1,1,1.
1, 1, 1 all have the same shape.

The above configuration is almost the same as that of the conventional iris die system, but in the present invention, the ring-shaped frame 2
is installed horizontally, and the forming dies 1, 1, 1, 1
is a special structure, i.e.

In the assembled state of each molding die 1, 1, 1, 1, the fifth
As shown in the figure, a pyramidal or conical cavity (hereinafter referred to as a pyramidal cavity) 5a and a prismatic or cylindrical cavity (hereinafter referred to as a columnar cavity) 5b are provided at the center of the mold.
The cavities 5 are arranged in a row in the height direction.

To be more specific, each of the forming dies 1 is formed into a pentagonal prism whose cross section is not uniform, and two adjacent dies are formed as shown in FIG.
The upper parts of the two side surfaces AIME and ABJI are formed into inclined surfaces 3 and 4 which are inclined at arbitrary angles (for example, 4 degrees) in opposite directions to the die axis, and the inclined surface 3 surrounded by one point AFHE is formed in an overhanging state. At the same time, an inclined surface 4 surrounded by one point ABGF is formed in the opposite manner, and such forming dies 1.1.1, 1 are brought into contact with each other at the inclined surfaces 3, 4.

Further, the rear surface CDLK is arranged so as to be in contact with the inner surface of the horizontal frame 2.

In this example, since a long powder compact with a square cross section was molded, a cavity consisting of a square truncated pyramid and a square prism with a cone angle of 8° was formed in the center of the mold.

Note that the conical cavity 5a and the columnar cavity 5
It is preferable that the boundary portion b, that is, the FG@ portion and FH portion in the drawing, form an appropriate curvature surface.

A drive mechanism 6 for synchronously reciprocating each die is provided on the back of the molding dies 1, 1, 1, 1.

In this embodiment, a fluid cylinder is used as the drive mechanism 6, but a crank mechanism or a mechanism using an inclined surface may be used.

Further, upper and lower pressing plates 7 and 8 are provided on the upper and lower surfaces of the horizontal frame 2, respectively, and liners 9, 10 are provided between the pressing plates γ, 8 and the upper and lower surfaces of the molding dies 1, 1, 1, 1.
are attached to the upper liner 9 and the upper presser plate T, and a forming die 1. ．． An opening 11 corresponding to the upper inclined cavity 5a of the cavity 5 composed of 1, 1, 1.
The lower liner 10 and the lower presser plate 8 are provided with a prismatic or cylindrical cavity 5 which is the lower part of the cavity 5.
The green compact delivery port 12 is shaped so as to communicate with b.

Furthermore, a hopper 15 for supplying powder 14 to the cavity 5 is provided in the opening 11, and the supply port 151 faces the tapered cavity 5a. A feed rod 16 is provided for feeding the powder and replenishing the powder 14.

The feed rod 16 synchronizes with the operation of the forming dies 1, 1, 1, 1 by the drive mechanism 6, advances into the slanted cavity 5a that is expanded during the returning process of the dies, and lightly touches the rear end of the formed object. It is designed to be pressed.

Therefore, when molding, first the powder is placed in the hopper 15.
4, and the powder 14 is filled into the cavity 5 from the supply port 151.

Incidentally, at this time, a temporary plug may be provided at the lower part of the columnar cavity 5b if necessary.

Next, the drive mechanism 6 is operated to move each molding die 1, 1 . L
Powder 14 is continuously charged from the hopper 15 while repeatedly sliding the hopper 1 back and forth at the same time with a constant stroke.

By doing this, the cavity 5 consisting of the conical cavity 5a and the columnar cavity 5b formed at the center H of the molding dies 1, 1, 1, 1 can be formed while keeping its cross-sectional shape similar. Since the contraction and expansion are repeated, the powder 14 filled in the cavity 5 is
The movement of the particles is suppressed by the frictional force between the particles and between the die walls 4, and the movement of the forming die 1, 1, 1, 1, without escaping upward from the opening of the cavity as shown in FIG.
1 inclined plane 4, 4, 4, 4 (especially FG in Fig. 2)
surrounding area).

Then, in the return process of the molding dies 1, 1, 1, 1 (cavity expansion process), the feed rod 16, which is mechanically or electrically synchronized with the movement of these dies, is moved to the supply port 1 of the hopper 15.
51 to lightly press the rear end surface of the pyramid-shaped or conical molded body 17 formed from the inclined surfaces 4, 4, 4, 4i in the advancing process of the molding die 1, 1° 1.1,
The molded body 17 is fed into the lower columnar cavity 5b in accordance with the expansion amount t of the conical cavity 5a, and at the same time, the gap corresponding to the descending valve of the molded body 1γ is naturally filled with the following powder 14 to form the primary powder. In the advancing process of the forming die 1, 1, 1, 1.

Compression molding is performed again from the inclined surface 4, 4, 4, 4).

When the cavity is expanded, the powder 14 is sent downward. Therefore, by continuously supplying the powder 14 with the hopper 15 and reciprocating the molding dies 1, 1, 1, 1 with a required stroke, the powder 14 is The molded product 1γ is continuously molded in fixed quantities, and the molded product 1γ is lowered through the columnar cavity 5b with its upper end always locked to the inclined surfaces 4, 4, 4, 4, and sequentially downward from the delivery port 12. It is something that is sent out.

Note that depending on the material of the powder 14, the angle of the inclined surface 4 of the die, etc., it is possible to feed and replenish the powder using its own weight without using the feed rod 16.

Here, the powder 14 includes iron powder, copper powder, aluminum powder and other single metal powders, non-metal powders and mixed powders of one or more thereof, cemented carbide powders 1. Any material such as high-speed steel powder may be used, and in the case of a material with poor compactability, it is preferable to add a viscous binder and form the material.

In addition, the present invention relates to other core metals. By disposing thin wires, whiskers, cut wires, etc. in the powder 14, it is possible to connect and obtain various long composite materials.

FIGS. 6 to 8 show the state in which such a long composite material is molded by the method of the present invention.

First, FIG. 6 shows a method of forming a long clad material.

A core metal 19 with a plug 18 at the lower end is inserted into the center of the cavity 5 between the forming dies 1 and 1 through the hopper 15, and a pipe-shaped feed rod 16' is fitted around the outer periphery of the core metal 19. In this state, the powder 14 is continuously supplied to the cavity 5 as described above, and the molding dies 1.1, 1, 1 are repeatedly reciprocated.

As a result, a long rod-shaped green compact having a core bar 19 in the center can be continuously formed.

Next, FIG. 1 shows a method of forming a fiber-reinforced composite elongated material, in which plugs 21 having the lower ends of thin wires 20, such as piano wires, attached at intervals are fitted into the lower part of the columnar cavity 5b. A weight member 22 for applying an appropriate tension to the thin wire 20f is suspended from the stopper 21, and the thin wire 20 is inserted into the conical cavity 5.
3 and the inside of the hopper 15 and guide it above the mold,
In this state, the forming dies 1, 1, 1, 1 are repeatedly reciprocated while the powder 14 is sequentially supplied from the hopper 15, and the inclined surface 4 is
, 4, 4, 4 to perform continuous molding.

In addition, in both the case of this FIG. 7 and the case of the above-mentioned FIG. 6, after the first molded body 17 is molded on the inclined surface 4° 4.4,4 after the start of molding.

The plugs 18 and 21 are naturally discharged from the outlet 12.

Thereafter, a continuous molded body 1T is sent out from the delivery port 12.

FIG. 8 shows a method of molding a dispersion-strengthened composite material. In this case, powder 141 is mixed with materials 23 such as whiskers and cut wires before being charged into the hopper 15. As in the case of FIG. 3, the molding dies 1, 1, 1, 1 may be reciprocated while being supplied to the cavity 5.

Furthermore, in the present invention, a long hollow material can be continuously molded by using a mandrel, or a filter can be molded by using an infiltration method.

FIG. 9 shows a method of forming a long hollow material, in which a fixed core bar 24 is inserted into the center of a conical cavity 5a, and a knob-shaped feed ball 16' is fitted around the outer periphery of the fixed core bar 24. The molding die 1, 1, 1, 1 is reciprocated while continuously supplying the powder 14 from the hopper 15 to the cavity 5.
In this way, the powder 14 is transferred to the fixed core bar 24 and the inclined surface 4 of the die.
, 4, 4, 4 compacted body 1 with a hole in the center
r is molded with each stroke and successively descends through the columnar cavity 5b to form a continuous, elongated hollow compacted powder.

Note that the molding dies 1, 1, 1, 1 shown in the figure are just an example, and the shape can be changed to have a rectangular cross section.

It goes without saying that it can be freely molded into regular polygonal or circular cross-sections, and although not shown, molded products 1γ, 1γ
It is also possible as an embodiment of the present invention to perform the above-mentioned forming while applying some reverse pressure from the front end surface of .

Furthermore, since the present invention sends out the molded bodies in a continuous state from the delivery port 12, continuous processing can be performed by attaching a sintering furnace or other heat treatment equipment below or to the side of the lower leg plate 8. can.

Next, specific examples of the method of the present invention are as follows.

Example 1 Using the apparatus shown in FIGS. 4 and 5, electrolytic copper powder (CE-5) was used as powder to form a long green compact of 10 mm square.

The molding die used at this time was 60 x 60 x 95 mm, the inclined surface was 4 degrees with respect to the die axis, the cone angle of the pyramidal cavity was 8 degrees, and the pitch, that is, the amount of expansion of the mold die, was 0.6 m.
m, the pressure condition was set at 4 tons per each drive mechanism (hydraulic cylinder in this case).

The resulting product in the process of being molded is as shown in the actual reference photo a in reference photo 1.

Its apparent density ρ was 5.95 g/Cr11.

Example 2 Using powder and atomized aluminum powder (VA-1520),
A long green compact with a square shape was molded.

The molding die, cavity cone angle, and pitch were the same as in Example 1, and the pressure was set to IT for each cylinder.

The actual long body that was obtained as a result is shown in reference photo 1.
b, and its apparent density is 2.53 g/
= was.

Example 3 Mill scale reduced iron powder (KIP-255MC) was used as a powder.
) was used to continuously mold a 10 square long green compact.

The molding conditions are the dimensions and shape of the molding die. The cavity cone angle was the same as in Example 1, the pitch was 0.8, and the molding pressure was 4t for each cylinder.

Reference photo 2 shows the actual photo of the product obtained in this example.
The apparent density of this material is 5.95.9/i
Met.

Example 4 Using the same powder as in Example 3, a long green compact of 8 ynm square was continuously molded.

The molding conditions at this time are the molding pressure of l per cylinder.
The procedure was the same as in Example 3 except that the pitch was 1.6 mounds and the apparent density of the obtained product was 7.42 g/-.

As is clear from the above examples, reference photos 1a and b, and reference photo 2, according to the method of the present invention, a very long green compact can be continuously molded, and the product has no cracks on the surface and has a good appearance. density can be obtained.

Since the present invention described above exhibits the following characteristics, it is a highly effective invention industrially.

(1) There is no restriction on the molding length, and very long green compacts can be obtained continuously.

(II) Since the special die is reciprocated and continuous molding is performed in fixed quantities on its inclined surface, the amount of processing per turn is small;
Therefore, the forming force can be reduced.

The equipment for molding the elongated body can be made small and simple.

(■) Powder is continuously supplied using a two-shaft rigid system, and long green compacts can be continuously molded by reciprocating the molding die, eliminating the need for troublesome processes such as peeling, improving workability and efficiency. It is easy to automate.

(IV) By simply adjusting the die stroke, you can create products with free cross-sectional dimensions, full length (tapered), etc.
Alternatively, a long stepped powder compact can be easily formed.

(■ Various long composite materials can be obtained easily and continuously by placing core metal, fine wire, cut wire, whiskers, etc. in powder, and long composite materials can be obtained in combination with a mandrel or infiltration method. It is also possible to mold hollow materials, filters, etc.

[Brief explanation of drawings]

Fig. 1 is a plan view schematically showing a mold used in the continuous molding method for long green compacts according to the present invention, Fig. 2 is a perspective view of a molding die according to the present invention, and Fig. 3 is a cross-sectional view showing the molding state. , Fig. 4 is a partially cutaway plan view showing an embodiment of the mold used in the method of the present invention, and Fig. 5 is a sectional view taken along the line ■-■ in Fig. 4, showing the cavity in an expanded state. . FIG. 6 is a cross-sectional view showing the molded state of the cladding material according to the present invention, FIG. 7 is a cross-sectional view showing the molded state of the fiber-reinforced composite material according to the present invention, and FIG. 8 is a cross-sectional view showing the molded state of the fiber-reinforced composite material according to the present invention. FIG. 9 is a sectional view showing the molded state of the hollow material according to the present invention. In the drawing, 1 is a molding die, 2 is a horizontal frame, and 3 is a molding die.
, 4 are side surfaces inclined in opposite directions. 5 is a cavity. 5a is a conical cavity. 5b is a columnar cavity, 14 is a powder, and 15 is a hopper.

Claims (1)

[Claims] 1 Four dies whose two adjacent sides are inclined in opposite directions with respect to the die axis are arranged in a horizontal frame so that the side surfaces are in contact with each other, and powder is continuously fed into the gap between the dies by gravity or by a feeding member. A continuous molding method for a long green compact characterized by repeatedly reciprocating the die while supplying the powder, compacting the powder in fixed quantities on the sloped side of the die, and continuously forming it into a long shape of an arbitrary length. .