Powder manufacturing device by plasma rotary electrode method

Abstract

To provide a powder manufacturing device by a plasma rotary electrode method which can prevent removal and vigorous projecting from each rotary roller even if a rotated electrode member becomes short.SOLUTION: A plurality of rotary rollers 11 are arranged around an electrode member 1 so that those outer peripheral surfaces come in contact with an outside surface of the electrode member 1 and support the electrode member 1, and are provided so as to rotate the electrode member 1 around a central axis. A plurality of support members 12 are mounted on an end face 11a on a side of one end 1a of the electrode member 1 of the corresponding rotary roller 11. The one end 1a of the electrode member 1 projects from the end faces 11a of each of the rotary rollers 11. Each of the support members 12 projects in an extension direction of the one end 1a of the electrode member 1, from the end faces 11a of the respective rotary rollers 11, and is arranged with a gap between itself and the outside surface of the one end 1a of the electrode member 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a powder manufacturing apparatus using a plasma rotating electrode method. [Background technology]

[0002] A conventional powder manufacturing apparatus using the plasma rotating electrode method has a long, thin electrode member made of metal or alloy and a plasma irradiation means capable of irradiating plasma toward one end of the electrode member.The plasma irradiation means irradiates plasma while the electrode member is rotating, thereby melting one end of the electrode member, and the resulting molten liquid is blown away and solidified by the centrifugal force of the rotation of the electrode member, thereby manufacturing spherical metal or alloy powder (see, for example, Non-Patent Documents 1 to 3).

[0003] In this conventional powder manufacturing apparatus using the plasma rotating electrode method, the electrode member is rotated while being supported at its rear end in a cantilevered state, which has the problem that the electrode member is prone to becoming unstable. Therefore, in order to more stably support the rotating electrode member, the present inventors have developed an apparatus having a plurality of rotating rollers arranged around the electrode member such that their outer peripheral surfaces are in contact with the outer surface of the electrode member and are rotatable about a rotation axis parallel to the central axis of the electrode member (see, for example, Patent Documents 1 and 2). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Koji Kakei, Rei Yokomori, Tomohiro Nishimaki, "Microstructure and Strength of Powder Sintered Nickel Superalloys Produced by Plasma Rotating Electrode Method", Journal of the Japan Institute of Metals, Vol. 80, No. 8, 2016, pp. 508-514 [Non-patent document 2] Masaharu Tokizane and Kazuo Isonishi, "Production of Ti Alloy Powder by Plasma Rotating Electrode Method," Resource Processing Technology, 1990, Vol. 37, No. 4, pp. 215-221 [Non-patent document 3] Ryohei Kumagai, "Preparation of Metallic Spherical Powders by Plasma Rotating Electrode Method," Materia, 1998, Vol. 37, No. 6, pp. 488-494 [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-25119 [Patent Document 2] Japanese Patent Publication No. 2022-42907 Summary of the Invention [Problem to be solved by the invention]

[0006] In a conventional powder production apparatus 50 using the plasma rotating electrode method described in Patent Documents 1 and 2, as shown in Fig. 3, one end 1a of an electrode member 1 is protruding from each of the rotating rollers 51, and plasma 2 is irradiated onto the protruding end 1a. By rotating the electrode member 1 and moving it toward the end 1a, metal or alloy powder can be continuously produced. However, with this conventional powder production apparatus 50, the electrode member 1 gradually becomes shorter as powder production continues, and when the other end 1b of the electrode member 1 moves close to the tip of each of the rotating rollers 51, the rotating electrode member 1 becomes unstable and detaches from each of the rotating rollers 51, potentially damaging the surrounding chamber or the apparatus itself.

[0007] The present invention has been made with an eye on such problems, and aims to provide a powder manufacturing device using the plasma rotating electrode method that can prevent the rotating electrode member from coming off each rotating roller and flying out with force even when the rotating electrode member becomes short. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides a powder manufacturing apparatus using a plasma rotating electrode method, which produces powder made of a metal or alloy by rotating an elongated metal or alloy electrode member around a central axis along its length while moving the electrode member toward one end and irradiating plasma toward the one end of the electrode member, and which includes a rotating member parallel to the central axis for rotating the electrode member around the central axis. The electrode member has one end protruding from the end face of each rotating roller, and each support member protrudes from the end face of each rotating roller along the extension direction of the one end of the electrode member, and is in contact with the outer surface of the one end of the electrode member or is arranged with a gap between it and the outer surface of the one end of the electrode member.

[0009] The powder production apparatus using the plasma rotating electrode method according to the present invention can continuously produce metal or alloy powder by supporting and rotating an electrode member with three or more rotating rollers arranged around the electrode member, with one end of the electrode member protruding from the end face of each rotating roller, and irradiating one end of the electrode member with plasma while moving the electrode member toward the one end. As powder production continues, the electrode member gradually shortens, and the other end of the electrode member moves close to the end face of each rotating roller and becomes detached from the rollers. However, because each supporting member protrudes from the end face of each rotating roller in the direction of extension of the one end of the electrode member, the electrode member that has detached from the rollers can be prevented from contacting one of the supporting members and being forcefully ejected from between the supporting members. This prevents the electrode member from being forcefully ejected and damaging the surrounding chamber or the apparatus itself.

[0010] The powder manufacturing apparatus using the plasma rotating electrode method according to the present invention is preferably configured so that when the electrode member that has moved toward the one end side comes off from the end face side of each rotating roller, the electrode member is supported by each support member. In this case, the electrode member that has come off each rotating roller can be reliably held between the support members, and the electrode member can be prevented from jumping out from between the support members.

[0011] In the powder manufacturing apparatus using the plasma rotating electrode method according to the present invention, when each support member is in contact with the outer surface of one end of the electrode member protruding from the end face of each rotating roller, the rotation of the electrode member can be prevented from becoming unstable even when the electrode member becomes short. This allows the electrode member that has come off the rotating roller to be stably and reliably held and supported by each support member. Furthermore, when each support member is arranged with a gap between it and the outer surface of one end of the electrode member protruding from the end face of each rotating roller, friction between the rotating electrode member and each support member can be prevented.

[0012] The powder manufacturing apparatus using the plasma rotating electrode method according to the present invention can move the electrode member toward one end by providing at least one rotating roller rotatably about a rotation axis that is oblique to the central axis of the electrode member. Furthermore, when all rotating rollers are provided rotatably about rotation axes parallel to the central axis of the electrode member, the powder manufacturing apparatus using the plasma rotating electrode method according to the present invention preferably includes a means for moving the electrode member toward one end. The means for moving the electrode member toward one end may be any means, and may be, for example, a pushing means provided at the other end of the electrode member that pushes the electrode member toward the one end.

[0013] In the powder manufacturing apparatus using the plasma rotating electrode method according to the present invention, each support member preferably has a cylindrical outer shape. In this case, the diameter of each support member may be the same as or smaller than the diameter of the corresponding rotating roller. Furthermore, each support member is preferably made of a heat-resistant material so as not to be melted by the plasma irradiated onto the electrode member.

[0014] In the powder manufacturing apparatus using the plasma rotating electrode method according to the present invention, each support member may have a cylindrical outer shape and be rotatable about a rotation axis parallel to the central axis. In this case, since the electrode member is rotating when it detaches from each rotating roller, each support member rotates in accordance with the rotation of the electrode member, thereby allowing the electrode member that has detached from each rotating roller to be smoothly held by each support member. Furthermore, in this case, even when each support member is in contact with the outer surface of one end of the electrode member protruding from the end face of each rotating roller, the rotation of each support member can prevent significant friction between the rotating electrode member and each support member.

[0015] Furthermore, when each support member is rotatably provided, the support member may rotate actively or passively. When each support member actively rotates, the support member may be rotated by any power, for example, by utilizing the rotational driving force of the corresponding rotating roller, or may be rotated independently of the rotation of the corresponding rotating roller.

[0016] In the powder manufacturing apparatus using the plasma rotating electrode method according to the present invention, each support member may be movable between a position in contact with the outer surface of the one end of the electrode member and a position spaced apart from the outer surface of the one end of the electrode member. In this case, for example, when the electrode member is long, moving each support member to a position spaced apart from the outer surface of the one end of the electrode member can prevent friction between the rotating electrode member and each support member. Furthermore, when the electrode member gradually shortens and the other end of the electrode member moves close to the end faces of the rotating rollers, moving each support member to a position spaced apart from the outer surface of the one end of the electrode member can prevent unstable rotation of the shortened electrode member and ensure stable and reliable support of the electrode member when it detaches from the rotating rollers. Furthermore, when the electrode member is supported by each support member, moving each support member to a position spaced apart from the outer surface of the one end of the electrode member can allow the electrode member to be removed, dropped, and recovered from between the support members.

[0017] The powder manufacturing apparatus using the plasma rotating electrode method according to the present invention may have a guide rail for guiding and recovering the electrode members supported by the support members from between the support members. In this case, the guide rail allows for efficient recovery of shortened electrode members. The recovered electrode members can also be reused. The guide rail may be located on the tip side of each support member (the opposite side to the electrode members) or below each support member. Any means may be used to move the electrode members supported by each support member onto the guide rail. For example, a pusher may be used to push the electrode members supported by each support member toward one end side, and a new electrode member may be used to push the electrode members from the tip side of each support member onto the guide rail. Alternatively, each movably mounted support member may be moved to a position where a gap is formed between the support members and the outer surface of one end of the electrode member, causing the electrode members to drop from between the support members and be transferred to the guide rail located below each support member. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a powder manufacturing device using a plasma rotating electrode method that can prevent the rotating electrode member from coming off each rotating roller and flying out with force even when the rotating electrode member becomes short. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a perspective view showing a state in which a powder manufacturing apparatus using a plasma rotating electrode method according to an embodiment of the present invention is in use. [Figure 2] FIG. 10 is a front view showing a modified example in which each support member moves in the powder manufacturing apparatus using the plasma rotating electrode method according to the embodiment of the present invention. [Figure 3] FIG. 1 is a perspective view showing a state in which a conventional powder manufacturing apparatus using a plasma rotating electrode method is in use. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 show a powder manufacturing apparatus using a plasma rotating electrode method according to an embodiment of the present invention. As shown in FIG. 1, a powder manufacturing apparatus 10 using the plasma rotating electrode method includes a plurality of rotating rollers 11, a plurality of support members 12, extrusion means 13, a guide rail 14, and a collection container 15.

[0021] The plasma rotating electrode method is a method for producing metal or alloy powder by rotating a thin, cylindrical metal or alloy electrode member 1 around its central axis along its length while moving the electrode member 1 toward one end 1a and irradiating plasma 2 toward one end 1a of the rotating electrode member 1. The rotation speed of the electrode member 1 is, for example, 20,000 rpm or higher. The plasma 2 is irradiated, for example, by a transferred or non-transferred plasma torch.

[0022] The rotating rollers 11 consist of three or more rollers, each having a cylindrical shape with a constant radius. The rotating rollers 11 are arranged parallel to each other at intervals around the elongated electrode member 1. Each rotating roller 11 is arranged parallel to the elongated electrode member 1, with the electrode member 1 sandwiched between them, with its outer peripheral surface in contact with the outer surface of the electrode member 1, and supports the electrode member 1. Each rotating roller 11 supports the electrode member 1 so that one end 1a of the electrode member 1 protrudes from the end face 11a on the side of the electrode member 1. Each rotating roller 11 is rotatable in the same direction around a rotation axis parallel to the central axis of the electrode member 1, so that the electrode member 1 rotates around its central axis.

[0023] Three or more support members 12 are provided corresponding to each rotating roller 11. Each support member 12 has a cylindrical outer shape with a diameter smaller than that of the corresponding rotating roller 11. Each support member 12 is attached to the end face 11a of the corresponding rotating roller 11 on the side of one end 1a of the electrode member 1 so as to protrude from the end face 11a in the extension direction of one end 1a of the electrode member 1. Each support member 12 is arranged with a gap between it and the outer surface of one end 1a of the electrode member 1 supported by the corresponding rotating roller 11. In the specific example shown in FIG. 1, there are three rotating rollers 11 and three support members 12.

[0024] The pushing means 13 is provided on the side of the other end 1b of the electrode member 1, and is configured to move the electrode member 1 toward the side of one end 1a by pushing the other end 1b of the electrode member 1 toward the side of one end 1a. The guide rails 14 are arranged below the tip sides (opposite the electrode member 1) of each support member 12. The collection container 15 is arranged at the lower end of the guide rails 14.

[0025] The powder manufacturing apparatus 10 using the plasma rotating electrode method is configured to support and rotate the electrode member 1 using rotating rollers 11 provided around the electrode member 1, with one end 1a of the electrode member 1 protruding from the end face 11a of each rotating roller 11, and to irradiate one end 1a of the electrode member 1 with plasma 2 while moving the electrode member 1 toward one end 1a using a pushing means 13, thereby continuously manufacturing metal or alloy powder. Furthermore, the powder manufacturing apparatus 10 using the plasma rotating electrode method is configured such that, as powder production continues, the electrode member 1 gradually becomes shorter, but by adding a new electrode member 1 to the other end 1b of the electrode member 1 and pushing the new electrode member 1 with the pushing means 13, it is possible to continuously supply the electrode member 1.

[0026] The powder manufacturing apparatus 10 using the plasma rotating electrode method is configured so that when the other end 1b of the gradually shortening electrode member 1 moves close to the end face 11a of each rotating roller 11 and comes off each rotating roller 11, each support member 12 surrounds the electrode member 1 and holds and supports it inside. The push-out means 13 pushes a new electrode member 1, causing the electrode member 1 supported between the support members 12 to drop from the tip end side of each support member 12. The guide rails 14 receive the electrode member 1c dropped from the tip end side of each support member 12 by the push-out means 13, and slide the electrode member 1c downward. The electrode member 1c that has slid down the guide rails 14 is stored inside a collection container 15.

[0027] Next, the operation will be described. In powder production apparatus 10 using the plasma rotating electrode method, when the electrode member 1 gradually becomes shorter as powder production continues, the other end 1b of electrode member 1 moves close to the end face 11a of each rotating roller 11 and becomes detached from each rotating roller 11. However, because each support member 12 is provided to protrude from the end face 11a of each rotating roller 11 in the extension direction of one end 1a of electrode member 1, it is possible to prevent the electrode member 1 that has detached from each rotating roller 11 from coming into contact with any of the support members 12 and flying out forcefully from between the support members 12. This makes it possible to prevent the electrode member 1 that has flew out forcefully from damaging the surrounding chamber or the apparatus itself.

[0028] In the powder manufacturing apparatus 10 using the plasma rotating electrode method, each support member 12 is arranged with a gap between it and the outer surface of one end 1a of the electrode member 1 protruding from the end face 11a of each rotating roller 11, thereby preventing friction from occurring between the rotating electrode member 1 and each support member 12. Furthermore, the powder manufacturing apparatus 10 using the plasma rotating electrode method can efficiently recover shortened electrode members 1c using the guide rail 14. The recovered electrode members 1c can also be reused.

[0029] As shown in FIG. 2, in a powder manufacturing apparatus 10 using the plasma rotating electrode method, each support member 12 may be movable between a position in contact with the outer surface of one end 1a of the electrode member 1 and a position where a gap is provided between the support member 12 and the outer surface of one end 1a of the electrode member 1. In this case, for example, when the electrode member 1 is long, by moving each support member 12 to a position where a gap is provided between the support member 12 and the outer surface of one end 1a of the electrode member 1, friction between the rotating electrode member 1 and each support member 12 can be prevented. Furthermore, when the electrode member 1 gradually shortens and the other end 1b of the electrode member 1 moves close to the end surface 11a of each rotating roller 11, each support member 12 can be moved to a position where it contacts the outer surface of one end 1a of the electrode member 1. This prevents the rotation of the shortened electrode member 1 from becoming unstable, and allows each support member 12 to stably and reliably hold and support the electrode member 1 when it comes off each rotating roller 11.

[0030] 2, each support member 12 may be provided rotatable about its central axis. This allows each support member 12 to rotate in accordance with the rotation of the electrode member 1 that has come off each rotating roller 11, so that the electrode member 1 that has come off each rotating roller 11 can be smoothly held by each support member 12.

[0031] Also, in the case shown in Figure 2, when guide rails 14 are arranged under each support member 12 and each support member 12 supports the electrode member 1, each support member 12 may be moved to a position where there is a gap between it and the outer surface of one end 1a of the electrode member 1, so that the electrode member 1 can be dropped and collected between each support member 12.

[0032] Furthermore, the powder manufacturing apparatus 10 using the plasma rotating electrode method may not have the extrusion means 13, and may instead have at least one rotating roller 11 rotatably provided about a rotation axis that is oblique to the central axis. In this case, the electrode member 1 can be moved toward the one end 1a by the rotating roller 11 that rotates about the oblique rotation axis. [Explanation of symbols]

[0033] 1 Electrode material 1a One end 1b Other end 2. Plasma 10. Powder manufacturing equipment using the plasma rotating electrode method 11 Rotating roller 11a End face 12 Support member 13 Extrusion means 14 Guide rail 15 Collection container 50 Conventional plasma rotating electrode method powder manufacturing equipment 51 Rotating roller

Claims

1. 1. A powder manufacturing apparatus using a plasma rotating electrode method for manufacturing metal or alloy powder by rotating an elongated metal or alloy electrode member around a central axis along its length, moving the electrode member toward one end, and irradiating plasma toward the one end of the electrode member, three or more rotating rollers disposed around the electrode member such that their outer peripheral surfaces are in contact with the outer surface of the electrode member to support the electrode member, and which are rotatable about rotation axes parallel to the central axis or rotation axes oblique to the central axis to rotate the electrode member around the central axis; three or more support members provided corresponding to each of the rotary rollers and attached to an end surface of the electrode member of the corresponding rotary roller on the one end side thereof, the electrode member has one end protruding from the end surface of each rotating roller, Each support member protrudes from the end surface of each rotating roller along the extension direction of the one end of the electrode member, and is in contact with the outer surface of the one end of the electrode member, or is disposed with a gap between it and the outer surface of the one end of the electrode member. This powder manufacturing device is characterized by the plasma rotating electrode method.

2. 2. A powder manufacturing apparatus using a plasma rotating electrode method according to claim 1, characterized in that when the electrode member moving toward the one end side comes off from the end face side of each rotating roller, the electrode member is supported by each support member.

3. 2. The powder manufacturing apparatus according to claim 1, wherein each support member has a cylindrical outer shape and is provided rotatable about a rotation axis parallel to said central axis.

4. 2. A powder manufacturing apparatus using a plasma rotating electrode method according to claim 1, wherein each support member is movable between a position in contact with the outer surface of the one end of the electrode member and a position in which a gap is provided between the support member and the outer surface of the one end of the electrode member.

5. 2. An apparatus for producing powder by a plasma rotating electrode method according to claim 1, further comprising: a pushing means provided on the other end side of said electrode member for pushing said electrode member toward said one end side.

6. 3. An apparatus for producing powder by a plasma rotating electrode method according to claim 2, further comprising a guide rail for guiding and recovering the electrode members supported by the respective support members from between the respective support members.

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