JPS6224482B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for producing metal granules that efficiently produces metal particles having a high melting point.

Traditionally, equipment for producing metal granules includes:
There are rotating electrode types and rotating cup types.

The rotating electrode type uses a metal that is to be made into granules as an electrode, generates an arc between the opposing electrodes, and uses the heat to melt the metal while rotating the electrode, cooling the metal as granules. A device is used to insert the liquid into the medium.

If such a device is adopted, the electrode rotation speed in principle requires a high rotation speed of 10,000 to 50,000 R.PM, and the manufacturing device is required to have extremely high precision, and it is expensive because it is produced in small quantities. It also has the disadvantage of poor productivity.

The rotating cup type rotates a rotating cup that receives molten metal at high speed, uses centrifugal force to eject the molten metal from a nozzle formed on its circumference, and cools and solidifies in a cooling medium, turning it into granules. It's trying to get something.

When this rotating cup type is adopted, it is difficult to maintain the ambient temperature inside the rotating cup for a long time.
The drawback was that it had to rely on batch production, which inevitably led to high production costs.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional art, and it is an object of the present invention to provide an apparatus for producing metal granules that is configured to be able to produce metal granules with high melting point extremely efficiently. The purpose is

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

FIG. 1 explains one embodiment of the present invention. In this figure, what is indicated by reference numeral 1 is an electrode called a bus bar, which is arranged vertically, and its lower end is formed in the base frame 2 via an insulating material 3 and a bearing 4 to the upper end of the rod of the cylinder 5. It is rotatably supported by a bearing receiver 6.

Further, within the base frame 2, the vicinity of the lower end of the electrode 1 is supported by guides 7, 7 so as to be able to rise and fall freely.

In addition, a power supply terminal 8 is provided near the guide 7.
is provided.

The electrode supply terminal 8 has a structure similar to a motor brush, and the electrode 8 can rotate and move up and down.
It is always in sliding contact with the power supply and is connected to the negative power supply.

A replaceable consumable electrode 9 is provided at the upper end of the electrode 1.

By the way, a cylindrical shaft 10 is arranged on the outside of the electrode 1 concentrically therewith.

The lower end of the cylindrical shaft 10 is supported by a thrust bearing 11 provided on the base frame 2, and an insulating material 12 is interposed between the upper and lower ends of the cylindrical shaft 10 and the electrode 1.

Further, a pulley 1 is provided on the outside of the lower end of the cylindrical shaft 10.
3 is fixed, and a motor 1 is attached to the outside of the pulley 13 and the base frame 2 via a support 14.
A belt 17 is stretched between a pulley 16 fixed to the output shaft of the motor 15, and rotation is transmitted to the cylindrical shaft 10 when the motor 15 is started.

A rotating cup 18 is fixed to the upper end of the cylindrical shaft 10, and the upper end of the electrode 9 faces inside the rotating cup 18 while being supported by a support 19 made of ceramic or the like.

A plurality of nozzles 2 are arranged radially in the rotating cup 18.
Set 0.

Incidentally, a rotary cylinder 21 is further arranged on the outside of the cylindrical shaft 10 so as to be concentric with the cylindrical shaft 10 .

The lower end of the rotary tube 21 is supported via a thrust bearing 23 to a support frame 22 fixed on the base frame 2, and the upper and lower ends thereof are rotated relative to the cylindrical shaft 10 via a bearing 24. It is freely supported on the shaft.

A pulley 25 is fixed in the middle of the rotary cylinder 21. A belt 29 is stretched between this pulley 25 and a pulley 28 fixed to the output shaft of a motor 27 attached to a support frame 26 provided on the side of the base frame 2. It is transmitted to the cylinder 21.

A cylindrical cooling water supply device 30 is attached to the base of the rotating cylinder 21 .

This cooling water supply device 30 has an annular flow path 31 on its inner circumferential surface, and this flow path 31 is connected to the rotary cylinder 21.
It communicates with an opening 21a formed on the side.

There are a plurality of these openings 21a, and cooling water supplied from a supply port 31a provided in the flow path 31 is supplied into the rotary cylinder 21 through these openings 21a.

Between this cooling supply device 30 and the rotating cylinder 21,
An airtight state is maintained using the bearing 32 and O-ring 32a as sealing materials.

The rotary cup 18 is attached to the upper end of the rotary cylinder 21.
A cylindrical body 33 is fixed in a state surrounding the cylindrical body 33, and the inside of this cylindrical body 33 communicates with the inside of the rotary cylinder 21 through an opening 21b formed in the cylindrical body 33 near its base.

The cylindrical body 33 has a spout 33a at a position corresponding to the nozzle 20 provided on the rotary cup 18.
Provide multiple.

The tip of the nozzle 20 is slightly inserted into the spout 33a.

Further, the outside of the cylindrical body 33 is covered with a casing 34, and one end of the casing 34 is formed with a discharge port 34a.

This discharge port 34a faces above the product receiving box 35, and a water tank 36 is provided below the product receiving box 35 to receive water falling through a small hole drilled in the bottom of the product receiving box 35. is located.

The rotary cylinder 21 is rotatably supported in the middle by a bearing 40 provided in a bearing part 39 integral with a support plate 38 supported by a column 37, and the casing 34 is supported with respect to the support plate 38. axis 41
Supported through.

Incidentally, an opening 18a is formed above the rotating cup 18, and a raw material rod 42 made of a metal with a high melting point is passed through the opening 18a.
is introduced into the rotating cup 18.

This raw material rod 42 is arranged opposite to the electrode 9,
It forms the other electrode, is guided by a guide 43 on the way, and has a power supply terminal 44 having the same structure as the power supply device 8 described above.
Connected to the positive power supply via.

Further, the lower end of the raw material rod 42 is covered with a heat-resistant inert gas injection tube 45.

The lower end of the inert gas injection tube 45 is inserted into the opening 18a of the rotating cup 18, and a coil 46 is wound around it. By supplying a high frequency current to this coil 46, the raw material rod 42 is
The raw material rod 42 is heated until it reaches near its melting point.

In addition, a supply port 4 is provided in the inert gas injection cylinder 45.
An inert gas such as argon or helium is constantly supplied through the rotary cup 5a, filling the inside of the rotating cup 18 with the inert gas to prevent unnecessary consumption of the electrodes and oxidation of the molten metal. .

Next, the operation of this embodiment configured as above will be explained.

First, start the motors 15 and 27, and rotate the cylindrical shaft 1.
0 and the rotary cylinder 21 are rotated.

Cooling water is then supplied into the rotating cylinder 21 from the supply port 31a of the cooling water supply device 30.

Then, the cooling water filling the inside of the rotary cylinder 21 is guided into the cylinder body 33 fixed to the upper part of the rotary cylinder 21 through the opening 21b provided at the upper part of the rotary cylinder 21. When trying to fill the inside of the cylinder 33, since the cylinder 33 is rotating together with the rotating cylinder 21, the cooling water rises along the wall surface of the cylinder 33 due to centrifugal force.
It is ejected from the ejection port 33a toward the casing 34 side. At this time, the tip of the nozzle 20 of the rotary cup 18 is partially inserted into the cooling water guided to the spout 33a.

On the other hand, negative and positive currents are supplied to the electrode 1 and the raw material rod 42 constituting the other electrode via power supply terminals 8 and 44, respectively.

Therefore, an arc is generated between the replaceable electrode 9 formed at the upper end of the electrode 1 and the raw material rod 42, and the raw material rod 42, which has been previously heated to near the melting point by the coil 46, Completely melted by arc.

Since the rotary cup 18 is rotating at a high speed, the molten metal is ejected in the form of particles into the cooling water from the nozzle 20 along the wall surface of the rotary cup 18.

Granular metal that comes into contact with cooling water is rapidly cooled,
The casing 34 with cooling water from the spout 33a
discharged inside.

Then, this granular metal falls into the product receiving box 35 from the discharge port 34a of the casing 34, and only the granular metal remains there, and the cooling water flows into the product receiving box 35.
is discharged to the water tank 36 side through a small hole in the bottom of the tank.

By the way, an arc is always generated inside the rotating cup 18, and the presence of this arc melts the raw material rod 42, and the heat of this arc keeps the inside of the rotating cup 18 at a constant temperature. This makes it possible to operate for long periods of time.

On the other hand, since the raw material rods 42 are sequentially melted by the arc, they are melted by a feeding device (not shown) in order to prevent the distance from the negative electrode 9 from changing. Adjustment is made so that there is always a constant distance between the negative electrode 9 and the negative electrode 9.

Although inert gas is supplied into the rotary cup 18, the minus side electrode 9 also wears out, so the distance between it and the raw material rod 42, which is the upper electrode, also changes. Therefore, in this embodiment, the cylinder 5 provided at the lower end of the electrode 1 is actuated,
The entire electrode 1 is raised according to the amount of consumption of the consumed electrode 9, and the distance between it and the raw material rod 42, which is the upper electrode, is kept constant.

Note that the rotation directions of the cylindrical shaft 10 and the rotary cylinder 21 may be the same or opposite.

Next, examples clarifying the conditions for implementing the present invention,
The specific effects based on this will be shown in experimental examples.

[Experiment example]

The specific implementation conditions of the present invention are as shown below.

(1) Diameter of rotating cup 18 100mm (2) Rotating diameter of nozzle 20 tip 260mm (3) Diameter of tip of nozzle 20 2.0mm (this can be 2.0 to 5.0mm) (4) Rotating cup 1 Rotation speed and peripheral speed 1000rpm, 13.6m/sec (This is 1000~3000rpm, 13.6~40.8m/sec)
(5) Rotation speed and circumferential speed of outer cylinder 33: 500 rpm, 6.8 m/sec (6) Current and voltage between electrode 9 and raw material rod 42: 200 to 400 A, 30 to 50 V (7 ) Distance between electrode 9 and raw material rod 42 5 to 10 mm The metal used in the experiment was 700g of aluminum for melting and deoxidation melted in a graphite crucible, and this molten metal was placed in a rotating cup 18 at 780°C. I poured hot water.

As a result, granules 47 having a relatively spherical shape and having a diameter of approximately 50 to 100 μm were obtained as shown in FIGS. 2 and 3. In addition, in FIGS. 2 and 3, what is shown around the particulate matter 47 is the embedding resin 48.

In this case, since the granules 47 are relatively small and extremely difficult to cut or polish, a desired plurality of granules 47 may be arbitrarily taken out of the large number of granules 47 obtained by the present invention. , it was embedded in a embedding resin 48 made of phenolic resin, cut out as appropriate, and its surface was polished to obtain what is shown in FIGS. 2 and 3.

As can be seen from FIG. 3, the granules 47 obtained by the present invention are polycrystalline, and the size of the crystals 47a is extremely small, 1 to 5 μm. Note that the crystal size of polycrystals obtained by mold casting such as die casting is usually 25 to 60 μm, for example.

The fact that the crystals 47a of the granules 47 obtained in the present invention are extremely small indicates that the tensile strength and elongation are correspondingly large, as can be seen from Hall-Petsch's law.

Further, in the present invention, since the granules 47 are rapidly cooled in water on the inner peripheral surface of the cylinder 33, a supersaturated solid solution is formed in the way the elements are mixed. Therefore, the sintering conditions for sintering the particulate matter 47 can be easily set. Furthermore, high strength can be expected through heat treatment.

As is clear from the above explanation, according to the present invention, since a rotating cup is used, high speed rotation is not required as much as in a rotating electrode type, and the accuracy of the entire device does not need to be made that high. good.

In addition, because the structure is such that an arc is generated within the rotating cup and the raw material rod is melted by this arc, the ambient temperature inside the rotating cup can be kept constant for a long time due to the generated arc. Continuous operation is possible.

Furthermore, since inert gas is constantly supplied into the rotating cup, the molten metal is not oxidized and the electrodes are less worn out.

Furthermore, the present invention has the following effects.

(1) The molten metal is dispersed by forced dispersion by the shearing action of water at the nozzle opening, so it is powerful and reliable, and has a large processing capacity.

(2) For the same reason as in the previous section, the size of the nozzle opening has almost no relation to the particle size of the product. Therefore, even when making fine particulate products, the nozzle opening can be large, making it easy to manufacture and eliminating the risk of clogging.

(3) Since the molten metal is directly jetted into the water and instantly dispersed, a large cooling rate can be obtained.

(4) Since the rotation speed and rotation direction of the inner rotary cup and the outer cylinder can be freely selected, the granulation conditions can be changed significantly and continuously.

(5) Continuous operation is possible.

(6) The tip of the nozzle is only slightly submerged in the water, and when it rotates, water resistance only acts on the tip of the nozzle, so the power required is relatively small.

(7) Polycrystalline granules consisting of fairly small crystals can be obtained extremely easily and reliably, and granules with good mechanical properties such as tensile strength and elongation can be obtained.

(8) Since relatively small granules can be obtained, they can be used as they are for sintering.

(9) Since granules can be rapidly cooled in the water layer,
The way the elements are mixed creates a supersaturated solid solution, the sintering conditions can be easily set when granules are pulverized and sintered, and high strength can be expected through heat treatment.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an example of the present invention, FIG. 2 is a sectional view showing an example of granular material obtained by the present invention, and FIG. 3 is a partially enlarged sectional view of FIG. FIG. 2 and FIG. 3 are organization charts corresponding to micrographs. 1 is an electrode, 2 is a base frame, 3, 12 is an insulating material, 4,
24 and 40 are bearings, 5 is a cylinder, 6 is a bearing receiver, 7 and 43 are guides, 8 is a negative power supply terminal, 9 is a consumable electrode, 10 is a cylindrical shaft, 11 and 23 are thrust bearings, 13 ，
16, 25, 28 are pulleys, 14 is a support stand, 1
5 and 27 are motors, 17 and 29 are belts, 18 is a rotating cup, 18a is an opening of the rotating cup, 19
20 is a nozzle, 21 is a rotating cylinder, 21a
22 and 26 are the openings of the rotating cylinder, 22 and 26 are the support frames, 30 is the cooling water supply device, 31 is the flow path, 31a is the opening of the flow path, 32 is the bearing, 32a is the O-ring, 33
33a is a cylindrical body, 33a is a spout of the cylindrical body, 34 is a casing, 34a is a discharge port of the casing, 35 is a product receiving box, 36 is a water tank, 37 is a column, 38 is a support plate,
39 is a bearing part, 41 is a support shaft, 42 is a raw material rod, 44
45 is a positive power supply terminal, 45 is an inert gas injection cylinder, 45a is a supply port of the injection cylinder, 46 is a coil, 47 is a granular material, and 48 is an embedded resin.

Claims (1)

[Claims] 1. An electrode is installed in a rotatable cylindrical shaft so that it can be raised and lowered, and a rotating cup that faces this electrode is fixed to the upper end of the cylindrical shaft, and a cylindrical body having a spout is provided on the outside of the rotating cup. A cooling water supply device is provided in a rotary cylinder arranged concentrically outside the cylinder shaft with respect to the cylinder, and the tip of a nozzle provided in the rotary cup is inserted into the cooling water near the spout of the cylinder, An apparatus for producing metal granules, characterized in that the raw material rod constituting the other electrode is introduced into the rotating cup via a preheating device, and an inert gas is constantly supplied into the rotating cup. .