WO2020004190A1

WO2020004190A1 - Thermal spraying device

Info

Publication number: WO2020004190A1
Application number: PCT/JP2019/024348
Authority: WO
Inventors: 克治門沢; 杉原　和佳
Original assignee: 東京エレクトロン株式会社
Priority date: 2018-06-26
Filing date: 2019-06-19
Publication date: 2020-01-02

Abstract

This thermal spraying device comprises a cathode, an anode, and an inner tubing. The cathode is approximately cylindrical and has a flow path which is formed along the center axis and through which a spraying material passes. The anode, disposed opposite the downstream end of the cathode, generates arc discharge plasma with the cathode. The inner tubing: is disposed such that the center axes of the cathode and the anode are substantially matching; and forms at least two flow paths within the cathode. The at least two flow paths formed by the inner tubing include, inside the inner tubing, a first flow path for passing a spraying material along the cathode center axis. The at least two flow paths formed by the inner tubing include, outside the inner tubing, a second flow path which is formed on the radial outer-side of the first flow path, at least a portion of which is surrounded by the cathode, and which is for passing an insulative gas.

Description

Thermal spray equipment

The following disclosure relates to a thermal spraying device.

The thermal spray device transports the thermal spray material and the working gas to the thermal spray gun, and applies electric power to the thermal spray gun to generate plasma. In the thermal spray gun, the thermal spray material is melted by the heat of the generated plasma, and is sprayed onto an object together with the working gas that has been turned into plasma to form a coating. The thermal spraying is a surface modification technique that generates plasma, melts the thermal spray material using the heat of the plasma, and forms a thermal spray coating on the surface of the target using the molten thermal spray material.

様々 Various techniques have been proposed to improve the quality of thermal spray coatings formed by thermal spray equipment. For example, a plasma spraying device has been proposed wherein the means for axially feeding powdered or gaseous material into the plasma torch has a supply tube for feeding powdered or gaseous sprayed material into the plasma channel inlet nozzle. Have been. The supply tube is arranged coaxially with the central axis of the thermal spraying device so that the thermal spray material passes through the hottest core of the plasma torch (Patent Document 1).

In addition, in order to improve the utilization efficiency of the spray material, the powder of the spray material is supplied to a discharge space formed between the first electrode and the second electrode so as to be slidable along the center axis of the plasma. There has been proposed a plasma torch provided with a spraying material introduction pipe to be heated (Patent Document 2).

JP 05-84455 A JP 2016-85811 A

By the way, it has been pointed out that when the powder particles of the thermal spray material are large, the thermal spray material is not melted even after passing through a plasma torch, and the surface quality of the thermal spray coating may be inferior (Patent) Reference 1). Further, in a thermal spraying apparatus using plasma, it is pointed out that the powder of the thermal spray material may be displaced from the central axis of the discharge space and the molten thermal spray material may adhere to the inner surface of the anode (Patent Document 2). ).

The present disclosure provides a technique for improving the thermal spray performance of a thermal spray apparatus in view of the above-described problems.

In the disclosed embodiment, the thermal spraying device includes a cathode, an anode, and an inner tube. The cathode is substantially cylindrical, and a flow path through which the thermal spray material passes is formed along the axis. The anode is arranged to face the downstream end of the cathode, and generates a plasma between the anode and the cathode by arc discharge. The inner tube is arranged so that the axes of the cathode and the anode substantially coincide with each other, and forms at least two flow paths in the cathode. At least two flow paths formed by the inner tube include a first flow passage in the inner tube that allows the thermal spray material to pass along the axis of the cathode. In addition, at least two flow paths formed by the inner pipe are provided outside the inner pipe, radially outside the first flow path, at least partially surrounded by the cathode, and provided with a second flow path through which the insulating gas passes. Including roads.

According to the disclosed embodiment, there is an effect that the thermal spraying performance of the thermal spraying device can be improved.

Drawing 1 is a figure showing an example of the composition of the thermal spraying device concerning an embodiment. FIG. 2 is a diagram illustrating an example of a configuration of the thermal spray gun according to the embodiment. FIG. 3A is a perspective view illustrating an example of a configuration of a cathode according to the embodiment. FIG. 3B is a cross-sectional view along X1-X1 of the cathode shown in FIG. 3A. FIG. 3C is a cross-sectional view illustrating another example of the configuration of the cathode according to the embodiment. FIG. 4A is a perspective view illustrating an example of the configuration of the anode according to the embodiment. FIG. 4B is an X2-X2 cross-sectional view of the anode shown in FIG. 4A. FIG. 5 is a diagram for describing a unit structure of the thermal spray gun according to the embodiment. FIG. 6A is a schematic cross-sectional view illustrating a plurality of flow paths formed in the thermal spray gun according to the embodiment. FIG. 6B is a schematic diagram illustrating a plurality of flow paths formed in the thermal spray gun according to the embodiment. FIG. 7A is a diagram illustrating an example of a flow velocity distribution in the thermal spray gun according to the embodiment. FIG. 7B is a diagram illustrating an example of a flow velocity distribution in a thermal spray gun having no double tube structure according to the embodiment.

Hereinafter, embodiments of the thermal spraying apparatus disclosed in the present application will be described in detail with reference to the accompanying drawings. The present disclosure is not limited by each embodiment described below. Further, it is necessary to keep in mind that the drawings are schematic, and the dimensional relationships of the respective elements, the ratios of the respective elements, and the like may be different from actual ones. Further, the drawings may include portions having different dimensional relationships and ratios. In addition, the embodiments can be appropriately combined within a range that does not contradict processing contents.

<Adhesion of thermal spray material in thermal spray gun>
As described above, it has been pointed out that the thermal spray material adheres to the inside of the thermal spraying device as one of the causes for lowering the performance of the thermal spraying device. The temperature of the part where the arc current is generated between the anode and the cathode during plasma spraying easily exceeds 1000 ° C. For this reason, if the powder of the thermal spray material adheres to the cathode inner wall heated to a high temperature by the arc discharge, it may be melted and fixed on the cathode inner wall. When the spraying gun is used for a long time, sticking and deposition of the spraying material becomes remarkable, and there is a possibility that a flow path formed at the axis of the cylindrical cathode and through which the spraying material passes is blocked.

点 In this regard, according to the experiments performed by the present inventors, the adhesion of the thermal spray material frequently occurs at the tapered portion where the inside diameter of the cathode is reduced. From this, it is considered that the more the wall portion with which the thermal spray material collides when the thermal spray material passes through the inside of the cathode, the more the thermal spray material tends to adhere.

However, it has been confirmed that even in the case of a cathode having no tapered portion, the sprayed material adheres to the inner wall of the cathode, and deposition proceeds with the portion where the attachment has started as a nucleus.

Therefore, the present inventors placed the sprayed powder on the base material whose temperature was controlled at room temperature, 205 ° C., and 405 ° C., respectively, and then dropped the sprayed powder that had not adhered by standing and hitting the base material. Thereafter, an experiment was conducted to examine the degree of adhesion of the thermal spray powder adhered to the substrate. As a result, it was found that when the temperature of the base material was room temperature, the adhered sprayed powder could be removed by a treatment such as physically rubbing. On the other hand, when the temperature of the base material was 205 ° C. or 405 ° C., it was not possible to completely remove the sprayed powder adhered by a treatment such as physical rubbing. From this, the present inventors have found that it is effective to control the temperature of the member through which the thermal spray material passes as low as possible in order to prevent the thermal spray material from adhering.

実験 The experiment was performed using lithium as the thermal spray material. Since lithium has high reactivity, it is distributed as a powder material in a state of being coated with lithium carbonate or the like. For this reason, when lithium is used as a thermal spray material, lithium carbonate is melted and the inner lithium is melted to form a thermal spray coating. The melting point of lithium is about 180 ° C, whereas the melting point of lithium carbonate is over 700 ° C.

<Example of configuration of thermal spraying device according to embodiment>
FIG. 1 is a diagram illustrating an example of a configuration of a thermal spraying apparatus 1000 according to the embodiment. The thermal spraying apparatus 1000 includes a thermal spray gun 1, a thermal spray material supply unit 2, a heat insulating gas supply unit 3, and a carrier gas supply unit 4. Thermal spraying apparatus 1000 also includes power supply 5 and cooling unit 6.

The thermal spray gun 1 is an axial supply type thermal spraying device that supplies thermal spray material from an axial center. A spray material mixed with a carrier gas (working gas) such as an argon gas passes through a flow path provided along the axis of the spray gun 1. The thermal spray gun 1 melts the thermal spray material by the heat of the plasma generated on the downstream side of the flow path, and sprays a plasma jet of the molten thermal spray material toward the target to form a thermal spray coating on the target. . Details of the configuration of the thermal spray gun 1 will be described later. In the following description of the embodiments, “upstream” and “downstream” indicate upstream and downstream of the flow of the thermal spray material. That is, the term “upstream” refers to the source of the thermal spray material supplied to the thermal spray gun 1, that is, the direction of the thermal spray material supply unit 2. The term “downstream” refers to the supply destination of the thermal spray material supplied to the thermal spray gun 1, that is, the direction in which the thermal spray target is arranged.

In this embodiment, the thermal spray material is a powder thermal spray material. The type of the thermal spray material is not particularly limited as long as it is a powder.

The thermal spray material supply unit 2 supplies the thermal spray material to the thermal spray gun 1. The thermal spray material supply unit 2 transports the thermal spray material to the thermal spray gun 1 using argon gas or the like as a carrier gas. The specific structure of the thermal spray material supply unit 2 is not particularly limited. The thermal spray material supply unit 2 is an example of a first supply unit.

(4) The heat-insulating gas supply unit 3 supplies a heat-insulating gas to the spray gun 1. The heat insulating gas is a gas for suppressing a temperature rise of the members of the thermal spray gun 1. As the heat insulating gas, for example, an argon gas can be used. The specific structure of the heat-insulating gas supply unit 3 is not particularly limited. The insulating gas supply unit 3 is an example of a second supply unit.

The carrier gas supply unit 4 supplies a carrier gas for sending a spray jet of the melted spray material from the spray gun 1 toward the target. As a carrier gas, for example, an argon gas can be used. The carrier gas supply unit 4 is an example of a third supply unit. Note that the same gas may be used as the insulating gas and the carrier gas. The heat insulating gas, the thermal spray material (including the carrier gas), the flow rate of the carrier gas, and the like can be independently controlled.

The power supply 5 supplies electric power for causing arc discharge between the electrodes of the thermal spray gun 1.

The cooling unit 6 is a functional unit for cooling each part of the thermal spray gun 1 heated by the thermal spraying process. The cooling unit 6 includes, for example, a storage unit that stores the cooling medium, a pump that sends out the cooling medium, and a pipe through which the cooling medium passes. A part of the conduit through which the cooling medium passes is disposed in the spray gun 1. The cooling medium is sent out to each part of the thermal spray gun 1 via a predetermined pipe, heated in the thermal spray gun 1, and then returned to the storage unit via a predetermined pipe. The temperature of the cooling medium is controlled by a temperature adjusting unit (not shown).

The thermal spraying apparatus 1000 also includes a chamber 7, a mounting table 8, a stage 9, a driving unit 10, a pump 11, an air conditioner 12, a control unit 13, and a storage unit 14.

The chamber 7 accommodates an object to be sprayed. The chamber 7 has a structure capable of maintaining the internal space at a vacuum. An injection port of the spray gun 1 protrudes into the chamber 7 from an upper wall of the chamber 7 so that a spray jet can be sprayed from the spray gun 1 onto an object placed in the chamber 7.

The mounting table 8 is a table on which an object to be sprayed is mounted on the upper surface. In the example of FIG. 1, the target object W is mounted on the mounting table 8. The mounting table 8 is positioned so that an object can be arranged at a position facing the injection port of the spray gun 1.

The stage 9 is a structure disposed below the mounting table 8. The stage 9 holds the mounting table 8 at a predetermined position.

The drive unit 10 is connected to the stage 9 to enable the two-dimensional movement of the mounting table 8 in a horizontal plane (perpendicular to the axis of the spray gun 1). The structure may be such that the mounting table 8 can be moved up and down and rotated manually.

Note that the detailed structures of the mounting table 8, the stage 9, and the driving unit 10 are not particularly limited as long as the structure has a structure that can place the object to be sprayed at a desired position.

The pump 11 is connected to the chamber 7 and evacuates the chamber 7. The pump 11 is, for example, a vacuum pump.

The air conditioner 12 is a device for maintaining the temperature and humidity in the room where the thermal spraying device 1000 is disposed at a predetermined value. Some thermal spray materials react to temperature and humidity, such as those that ignite when contacted with water. For this reason, the temperature and humidity in the room where the thermal spraying device 1000 is disposed are controlled by the air conditioner 12 according to the characteristics of the thermal spraying material to be used.

The control unit 13 controls the operation of each unit of the thermal spraying apparatus 1000. The storage unit 14 stores a program for controlling the operation of each unit of the thermal spraying apparatus 1000. The control unit 13 and the storage unit 14 are, for example, computers having a CPU (Central Processing Unit) and a memory. The storage unit 14 stores programs for controlling various processes executed in the thermal spraying apparatus 1000. The control unit 13 controls the operation of the thermal spraying apparatus 1000 by reading and executing the program stored in the storage unit 14.

Note that such a program may have been recorded on a computer-readable storage medium, and may be installed in the storage unit 14 from the storage medium. Examples of the storage medium readable by the computer include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magneto-optical disk (MO), and a memory card.

In the thermal spraying apparatus 1000 configured as described above, first, an object to be thermal sprayed is placed on the mounting table 8 in the chamber 7. Then, under the control of the control unit 13 based on the program stored in the storage unit 14, the thermal spray material mixed with the carrier gas is supplied to the thermal spray gun 1 from the thermal spray material supply unit 2. Insulating gas is supplied from the insulating gas supply unit 3 to the spray gun 1. Further, a carrier gas is supplied from the carrier gas supply unit 4 to the spray gun 1. On the other hand, the control unit 13 controls the power supply 5 to generate an arc discharge in the thermal spray gun 1 to generate plasma and to melt the supplied thermal spray material. The molten thermal spray material, together with the carrier gas supplied from the carrier gas supply unit 4, becomes a thermal spray jet and collides with an object to form a thermal spray coating. During the thermal spraying process, the temperature and humidity are controlled by the air conditioner 12 in the room where the thermal spraying device 1000 is disposed. During the thermal spraying process, the inside of the chamber 7 is maintained at an atmospheric pressure or a vacuum atmosphere by the pump 11.

<Example of spray gun configuration>
FIG. 2 is a diagram illustrating an example of a configuration of the thermal spray gun 1 according to the embodiment. As shown in FIG. 2, the thermal spray gun 1 includes a space S formed along the axis of the thermal spray gun 1, a cathode C, and an anode A arranged to face the cathode C. The space S is a substantially cylindrical space. At least two flow paths described later are formed in the space S. The cathode C is arranged to surround the downstream portion of the space S, and the thermal spray material passes along the axis of the cathode C. The anode A is arranged to face the downstream end of the cathode C, and generates plasma with the cathode C by arc discharge. The cathode C and the anode A are physically and electrically separated electrodes forming a pair. An arc discharge is generated between the cathode C and the anode A in a circumferential shape. A flow path is formed around the cathode C and the anode A, through which a cooling medium CM for absorbing heat generated by the arc discharge circulates. The cooling medium CM is, for example, water. The flow path in which the cooling medium CM circulates forms a part of the cooling unit 6 shown in FIG.

FIG. 3A is a perspective view showing an example of the configuration of the cathode C according to the embodiment. FIG. 3B is a cross-sectional view taken along the line AA of the cathode C shown in FIG. 3A. As shown in FIG. 3A, the cathode C has a cylindrical portion C1 having a cylindrical shape, and a projection portion C2 provided at an upstream end of the cylindrical portion C1 and protruding radially outward of the cylindrical portion C1. In a state where the cathode C is attached to the thermal spray gun 1, the cylindrical portion C1 is disposed on the downstream side, and the projection C2 is disposed on the upstream side. The cylindrical portion C1 has a tapered shape tapering toward the downstream end. The inner diameter D1 at the upstream end of the cylindrical portion C1 is larger than the inner diameter D2 at the downstream end of the cylindrical portion C1 (see FIG. 3B). However, the shape of the cylindrical portion C1 of the cathode C is not particularly limited, and may be a shape having no taper. For example, as shown in FIG. 3C, the inner diameter of the cylindrical portion C1 of the cathode C may be formed in a straight shape. FIG. 3C is a cross-sectional view illustrating another example of the configuration of the cathode C according to the embodiment. In the example of FIG. 3C, the inner diameter D1 of the upstream end of the cylindrical portion C1 and the inner diameter D2 of the downstream end substantially match. When mounted on the thermal spray gun 1, the axis of the cathode C substantially coincides with the axial center of the thermal spray gun 1. The protrusion C2 is a locking portion, for example, a flange that locks the cathode C at a predetermined position when the cathode C is attached to the thermal spray gun 1. The outer diameter D3 of the projection C2 is different from the outer diameter of the cylindrical portion C1 in order to increase the efficiency of heat transfer to other members of the spray gun 1 that comes into contact with the cathode C when the cathode C is attached to the spray gun 1. It is preferable to make the difference as large as possible.

FIG. 4A is a perspective view showing an example of the configuration of the anode A according to the embodiment. FIG. 4B is a cross-sectional view taken along the line BB of the anode A shown in FIG. 4A. As shown in FIG. 4A, the anode A has a cylindrical portion A1 having a cylindrical shape, and a protrusion A2 provided at an upstream end of the cylindrical portion A1 and protruding radially outward of the cylindrical portion A1. When the anode A is attached to the spray gun 1, the cylindrical portion A1 is disposed on the downstream side, and the protrusion A2 is disposed on the upstream side. In the state where the anode A is attached to the thermal spray gun 1, the axial center of the anode A substantially coincides with the axial center of the thermal spray gun 1. The protrusion A2 is a locking portion, for example, a flange that locks the anode A at a predetermined position when the anode A is attached to the thermal spray gun 1. The specific configuration of the anode A is not particularly limited as long as the outer diameter of the protrusion A2 is larger than the outer diameter of the cylindrical portion A1. The outer diameter of the projection A2 should be as large as possible from the outer diameter of the cylindrical part A1 in order to increase the efficiency of heat conduction to a member that comes into contact with the anode A when the anode A is attached to the thermal spray gun 1. Is preferred.

戻り Returning to FIG. 2, the thermal spray gun 1 has a transport pipe section 100, a cathode section 200, and an anode section 300 from the upstream side to the downstream side. The transport pipe section 100, the cathode section 200, and the anode section 300 each constitute an independent unit, and have a structure that can be detached independently.

<Example of configuration of transport pipe section 100>
The transport pipe section 100 has an inner pipe 101, a main body section 102, a holding flange 103, and an adjusting screw 104.

The inner pipe 101 is a hollow pipe that forms two or more flow paths in the space S. When the inner tube 101 is attached to the spray gun 1, the axis of the inner tube 101 substantially coincides with the axes of the cathode C and the anode A. The inner pipe 101 extends from the upstream end of the transport pipe section 100 toward the downstream end, and has a length reaching the downstream end of the cathode C along the axis of the cathode C arranged downstream of the transport pipe section 100. . The upstream end of the inner pipe 101 is located on the upstream side of the upstream end of the transport pipe section 100, and is connected to a pipe for transporting the thermal spray material extending from the thermal spray material supply section 2 (not shown).

内部 The internal space of the inner tube 101 forms a first flow path F1 (see FIG. 6) through which the thermal spray material passes along the axis of the cathode C. The inner pipe 101 is fitted in a hollow cylindrical main body 102, and a second flow path F2 (FIG. 6) through which heat insulating gas flows between the inner wall of the main body 102, the inner wall of the cathode C, and the outer wall of the inner pipe 101. Ref) is formed. The second flow path F2 is formed radially outward of the first flow path F1. The inner tube 101 is arranged such that at least a part of the second flow path F2 is surrounded by the cathode C. For this reason, the outer diameter of the inner tube 101 is formed to be smaller at least in part than the inner diameters of the main body 102 and the cathode C. In the example of FIG. 2, the inner tube 101 has substantially the same inner diameter and outer diameter in the axial direction. However, the inner pipe 101 may be formed in a tapered shape.

The inner pipe 101 is a hollow pipe formed of a high melting point material such as tungsten or zirconia. The dimensions of the inner tube 101 are, for example, an outer diameter of φ4 mm (mm) and an inner diameter of φ3 mm.

The main body 102 has a flange 102a, a body detail 102b, a first cylindrical portion 102c, and a second cylindrical portion 102d from the upstream end to the downstream end of the main body 102. The main body 102 is a substantially cylindrical member having a space S formed therein. The flange 102a, the body detail 102b, the first cylindrical portion 102c, and the second cylindrical portion 102d are integrally formed.

The flange 102a is located at the upstream end of the main body 102 and has a larger outer diameter than the body detail 102b. In the example of FIG. 2, the flange 102a and the body detail 102b are configured as portions having different outer diameters, but the flange 102a and the body detail 102b may have the same outer diameter.

The first cylindrical portion 102c has an outer diameter larger than the body detail 102b. However, the first cylindrical portion 102c and the body detail 102b may have the same outer diameter. A portion of the first cylindrical portion 102c is formed with a lateral hole 110 and a screw portion 111 that extend from the outside in the radial direction toward the axis and penetrate the first cylindrical portion 102c. The horizontal hole 110 is a hole extending in the radial direction from the inner circumference of the first cylindrical portion 102c to a predetermined radial position of the first cylindrical portion 102c. The screw portion 111 is a threaded hole that communicates with the lateral hole 110 and extends radially toward the outer periphery of the first cylindrical portion 102c. The threaded end of the pipe connected to the heat-insulating gas supply unit 3 is screwed into the screw 111. The thread portion 111 is configured to engage with, for example, a tube fitting.

第 A second cylindrical portion 102d having a smaller outer diameter than the first cylindrical portion 102c is formed downstream of the first cylindrical portion 102c. The second cylindrical portion 102d is a sleeve extending downstream from the first cylindrical portion 102c. A threaded surface is formed on the outer peripheral surface of the second cylindrical portion 102d over a predetermined length from the upstream end. The threaded surface is formed to have a dimension that is screwed with a threaded portion 201c of the cathode portion 200 described later. The second cylindrical portion 102d has a lateral hole extending radially from the inner periphery to the outer periphery and penetrating the second cylindrical portion 102d. The side hole is formed as a threaded hole and has a dimension that allows the adjustment screw 104 to be screwed. A plurality of lateral holes are arranged at equal intervals over the outer circumferential direction of the second cylindrical portion 102d. For example, the lateral holes are formed at three places on the outer periphery of the second cylindrical portion 102d. However, the number of side holes is not particularly limited. The number of the horizontal holes may be four or more as long as the inner tube 101 inserted into the main body 102 can be fixed by the adjusting screw 104 screwed into the horizontal hole. Further, the position where the lateral hole is formed is not particularly limited as long as it is on the second cylindrical portion 102d.

The adjustment screw 104 fixes the inner tube 101 in the main body 102. The adjusting screw 104 is, for example, a set screw. The adjustment screw 104 can be formed of metal, SUS, or the like. The adjustment screw 104 is an example of a second locking portion.

内径 The inner diameter of the main body 102 has a size that fits with the inner pipe 101 on the upstream side. In the example of FIG. 2, the inner diameter of the main body 102 has a size that fits with the inner pipe 101 up to the upstream side of the flange 102a, the body detail 102b, and the first cylindrical portion 102c. The inner diameter of the main body 102 is larger than the outer diameter of the inner tube 101 from the downstream side, that is, from the middle of the first cylindrical portion 102c to the downstream end of the second cylindrical portion 102d. For example, the main body 102 is formed so that the inner diameter is about 1 mm to 2 mm larger than the outer diameter of the inner tube 101 on the downstream side. However, the position where the inner diameter of the main body 102 changes is not particularly limited as long as the second flow path F2 and the lateral hole 110 can be configured to communicate with each other. The inner diameter of the downstream side of the main body 102 is substantially the same as the inner diameter of the cathode C.

The holding flange 103 is formed to have substantially the same outer diameter and inner diameter as the flange 102a. The holding flange 103 is fixed to the flange 102 a at the upstream end of the main body 102 with the inner pipe 101 inserted into the main body 102. The holding flange 103 is, for example, screwed to the flange 102a in the axial direction. The holding flange 103 and a fixing means such as a screw for fixing the holding flange 103 to the flange 102a are examples of a first locking portion.

取り付ける When attaching the inner tube 101 to the main body 102, first, attach the O-ring 107 near the upstream end of the inner tube 101. Then, the inner tube 101 is inserted from the upstream end of the main body 102, and the O-ring 107 is adjusted so as to be located at the upstream end of the main body 102. Then, the upstream end of the inner pipe 101 is inserted into a hole formed in the center of the holding flange 103. Thereafter, the holding flange 103 is fixed to the main body 102 by pressing the downstream end face of the holding flange 103 against the main body 102 and crushing the O-ring 107 while screwing the holding flange 103 from the upstream end side. Thereby, the inner tube 101 is fixed to the main body 102. Further, the O-ring 107 functions as a vacuum seal that seals a gap between the inner tube 101 and the main body 102.

The inner tube 101 is further fixed to the main body 102 at the second cylindrical portion 102d of the main body 102. As described above, the inner diameter of the main body 102 is configured to be larger than the outer diameter of the inner tube 101 on the downstream side. Therefore, when the inner pipe 101 is inserted into the main body 102, the inner pipe 101 is in a cantilever state with the holding flange 103 as a fulcrum. For this reason, in the downstream portion of the inner pipe 101, the interval between the inner peripheral surface of the main body 102 and the outer peripheral surface of the inner pipe 101 is not constant over the circumference. Then, by screwing the adjusting screw 104 into the lateral hole formed in the second cylindrical portion 102d, the distance between the inner peripheral surface of the main body 102 and the outer peripheral surface of the inner tube 101 is adjusted to be uniform in the circumferential direction. .

<Example of configuration of cathode unit 200>
The cathode section 200 has a main body section 201, a cover 202, and a spacer 203.

The main body 201 is a hollow cylindrical member. The second cylindrical portion 102d of the transport pipe portion 100 is accommodated in a cylindrical space formed along the axis of the main body 201. When accommodating the second cylindrical portion 102d, the O-ring 204 is interposed between the main body portion 201 and the second cylindrical portion 102d so that a vacuum sealing function is exhibited. On the inner peripheral surface of the main body part 201, a screw part 201a to be screwed with the threaded surface of the second cylindrical part 102d of the transport pipe part 100 is formed. The screw part 201a is formed on the inner peripheral upstream side of the main body part 201. Further, the inner peripheral downstream side of the main body 201 has a size fitting with the outer diameter of the second cylindrical portion 102d.

突起 At the inner peripheral downstream end of the main body 201, a protruding portion 201b protruding radially inward is formed. The protrusion 201b is configured such that the inner diameter is fitted to the outer diameter of the cylindrical portion C1 of the cathode C. In a portion where the screw portion 201a and the protrusion 201b are not formed, the inner diameter of the main body 201 is substantially the same as the outer diameter of the protrusion C2 of the cathode C.

空間 A space 206 through which the cooling medium CM flows is also formed in the main body 201. The space 206 communicates with at least two pipes 207, and the cooling medium CM circulates through the pipes 207. The space 206 and the pipeline 207 constitute a part of the cooling unit 6. FIG. 2 shows only one conduit 207.

The cover 202 is a cylindrical member that covers the main body 201 from the outer peripheral side. The cover 202 is formed of an insulating material. An O-ring groove 210 is provided on the upstream end surface near the outer periphery of the main body 201, and when the cover 202 is mounted on the main body 201, the O-ring is sandwiched between the two and fixed. The axial length of the cover 202 is set such that the downstream end of the cover 202 is located downstream of the downstream end of the main body 201 when the cover 202 is mounted on the outer periphery of the main body 201. In the example of FIG. 2, the axial length of the cover 202 is such that when the cover 202 is mounted with the spacer 203 fixed to the main body 201, the entire main body 201 and the spacer 203 are covered by the cover 202. Is set to The means for fixing the spacer 203 to the main body 201 is not particularly limited.

横 Near the downstream end of the cover 202 which comes into contact with the spacer 203, a plurality of lateral holes 212 are formed at equal intervals along the circumferential direction. The lateral hole 212 extends from the inner circumference to the outer circumference of the cover 202 to near the center in the radial direction. Further, a screw portion 213 communicating with the lateral hole 212 and penetrating the cover 202 in the radial direction together with the lateral hole 212 is formed. The screw portion 213 is a threaded hole. The screw part 213 is screwed with a threaded end of a pipe part for supplying the carrier gas from the carrier gas supply part 4. The thread 213 is configured to engage with, for example, a tube fitting.

The spacer 203 is a ring-shaped insulating member. The spacer 203 has a groove formed on the outer circumference in the circumferential direction. A plurality of holes 211 are formed on the bottom surface of the groove at uniform intervals in the circumferential direction. The plurality of holes 211 penetrate the spacer 203 in the radial direction from the bottom surface of the groove to the inner peripheral surface. The carrier gas introduced from the lateral hole 212 and the screw portion 213 formed in the cover 202 enters the space formed by the groove of the spacer 203 between the spacer 203 and the cover 202, and passes through the plurality of holes 211 to connect with the cathode C. It is supplied between the anodes A. Since the spacer 203 and the cover 202 are made of an insulating material, the state where the cathode C and the surroundings are insulated is maintained. The electrically separated state is maintained between the cathode C and the anode A.

<Example of configuration of anode unit 300>
The anode section 300 is a cylindrical member having a cylindrical hole formed along the axis. The inner diameter of the anode part 300 is formed to be substantially the same size as the outer diameter of the cylindrical part A1 of the anode A. The outer diameter of the anode section 300 is substantially the same as the outer diameter of the cover 202 of the cathode section 200.

上流 The upstream end face of the anode part 300 is formed in a size that the projection A2 of the anode A is locked. A ring-shaped projection 301 having substantially the same radial dimension as the downstream end face of the cover 202 is provided on the outer edge of the upstream end face of the anode section 300. The inner diameter of the protrusion 301 is substantially the same as the outer diameter of the protrusion A2 of the anode A. The step formed on the upstream end face of the anode section 300 formed by the projection section 301 functions as a positioning section when the anode A is attached to the anode section 300.

O-

ring grooves

302 and 303 are formed on the upstream end face of the anode section 300 at the portion where the anode A contacts and the portion where the cover 202 contacts. O-rings are arranged in the O-

ring grooves

302 and 303 when the anode unit 300 is attached to the cathode unit 200. When the O-ring is pressed, the space between the cathode section 200 and the anode section 300 is sealed. Further, in the example of FIG. 2, a screw part 214 is formed by cutting out a part of the outer peripheral surface of the cover 202, and the cover 202 and the anode part 300 are screwed with the screw part 214 by a screw.

{Circle around (3)} A space 304 through which the cooling medium CM flows is formed in the anode section 300. The space 304 communicates with at least two pipes 305, through which the cooling medium CM circulates. The space 304 and the conduit 305 constitute a part of the cooling unit 6. FIG. 2 shows only one conduit 305.

フランジ Furthermore, a flange 306 for fixing the thermal spray gun 1 to the chamber 7 is provided at a downstream end of the anode part 300. The flange 306 is a projection that extends radially outward at the downstream end of the anode unit 300. A screw hole is formed in the flange 306 so as to penetrate the flange 306 in the axial direction. The thermal spray gun 1 can be screwed to the chamber 7 using the screw hole.

<Unit structure>
FIG. 5 is a diagram for describing a unit structure of the thermal spray gun 1 according to the embodiment. FIG. 5 shows a state in which the thermal spray gun 1 is disassembled into a transport pipe section 100, a cathode C, a cathode section 200, an anode A, and an anode section 300.

(4) The transport pipe section 100 can be detached from the cathode section 200 by rotating the transport section 100 about the cathode section 200 around the axis. The transport pipe section 100 and the cathode section 200 are mutually connected by screwing a screw section 201a formed on the main body section 201 of the cathode section 200 and a threaded surface formed on the second cylindrical section 102d of the transport pipe section 100. It is fixed to. Therefore, the transport pipe 100 can be easily detached from the cathode 200 by rotating the entire transport pipe 100 around the axis of the transport pipe 100 as a rotation axis.

取り外す When the transport pipe 100 is removed from the cathode 200, the cathode C housed in the main body 201 of the cathode 200 is exposed. Since the cathode C is held in a state of being locked to the projection 201b of the main body 201, it can be easily taken out from the upstream side. Therefore, replacement and maintenance of the cathode C can be easily performed. When the cathode C is housed in the thermal spray gun 1, the transport tube 100 is mounted from above the cathode C, so that the cathode C and the main body 201 are in close contact with each other, and heat transfer is performed well.

(4) Further, the anode part 300 can be easily removed from the cathode part 200 by loosening the screw of the screw part 214 that fastens the cover 202 of the cathode part 200 and the anode part 300. Further, the anode A is locked to the anode unit 300 by placing the protrusion A2 on the upstream end surface of the anode unit 300. Therefore, when the anode section 300 is detached from the cathode section 200, the anode A can be easily taken out. Therefore, replacement and maintenance of the anode A can be easily performed.

Thus, the transport tube 100 and the anode 300 can be integrally removed from the cathode 200. Therefore, there is no need to disassemble the thermal spray gun 1 finely for replacement and maintenance of the anode A and the cathode C, and replacement and maintenance of the anode A and the cathode C can be easily performed.

Further, since the transport pipe section 100 can be easily removed from the cathode section 200, replacement and maintenance of the inner pipe 101 can be easily performed. The inner pipe 101 is fixed to the transport pipe section 100 by a holding flange 103, a screw, an O-ring (first locking portion), and an adjusting screw 104 (second locking portion). The holding flange 103 can be easily removed by removing a screw without removing the transport pipe section 100 from the cathode section 200. The adjusting screw 104 can be easily removed because the adjusting screw 104 is exposed to the outside by removing the transport pipe section 100 from the cathode section 200. Therefore, even if the thermal spray material adheres to the inner tube 101, the inner tube 101 can be easily removed, and replacement and maintenance can be easily performed.

<Double tube structure in the embodiment>
Next, the double pipe structure provided in the thermal spray gun 1 according to the embodiment will be further described. 6A and 6B are views for explaining a double-pipe structure in the thermal spray gun 1 according to the embodiment. Here, the double tube structure is one in which a flow path through which a heat insulating gas passes is provided outside a flow path through which the thermal spray material passes. The double tube structure improves the performance of the thermal spraying device by suppressing the temperature rise of the members of the thermal spray gun 1 and suppressing the deposition of the thermal spray material.

FIG. 6A is a schematic cross-sectional view showing a plurality of flow paths formed in the thermal spray gun 1 according to the embodiment. FIG. 6B is a schematic diagram illustrating a plurality of flow paths formed in the thermal spray gun 1 according to the embodiment.

FIG. 6A shows a state near the cathode C in a state where the inner tube 101 is inserted into the main body 102 and the cathode C. In the state of FIG. 6A, the inner pipe 101 extends to the downstream end of the cathode C through the inside of the main body 102 of the transport pipe 100. The inner tube 101 is fixed so that the axis thereof substantially coincides with the axis of the main body 102 and the cathode C. That is, the inner tube 101 is locked to the holding flange 103 via the O-ring 107 at the upstream end of the main body 102, and is fixed to the second cylindrical portion 102d by the adjusting screw 104 at a predetermined position on the downstream side. .

とき When the inner tube 101 is mounted as shown in FIG. 6A, two flow paths extending in the axial direction are formed in the spray gun 1. One is a first flow path F1 formed along the axial center of the cathode C. The other is a second flow path F2 formed outside the first flow path F1 in the radial direction and at least partially surrounded by the cathode C.

The first flow path F1 is a flow path formed inside the inner pipe 101. The first flow path F1 extends axially to the downstream end of the cathode C along the axis of the transport pipe 100 and the cathode C. The upstream end of the first flow path F1 is connected to the thermal spray material supply unit 2. The thermal spray material supplied from the thermal spray material supply unit 2 is sent downstream through the first flow path F1.

The second flow path F2 is a flow path formed between the outer circumference of the inner tube 101, the inner circumference of the main body 102, and the inner circumference of the cathode C. As described above, the inner diameter of the main body 102 is configured to be larger by about 1 mm to 2 mm than the outer diameter of the inner tube 101 on the downstream side. Therefore, on the downstream side of the main body 102, a second flow path F2 having a ring-shaped cross section with a width of about 1 to 2 mm is formed between the outer circumference of the inner tube 101 and the inner circumference of the main body 102. 6B). Insulation gas is supplied into the main body 102 through a lateral hole 110 and a screw portion 111 (see FIG. 2) penetrating the first cylindrical portion 102c in the radial direction. The lateral hole 110 and the screw portion 111 are configured to communicate with the second flow path F2. Therefore, the heat-insulating gas can flow through the second flow path F2 from any portion of the transport pipe section 100 disposed upstream of the cathode C to the downstream. In FIG. 6A, the flow of the thermal spray material is indicated by a white arrow, and the flow of the heat insulating gas is indicated by a dotted arrow.

調整 At least a portion of the adjusting screw 104 protrudes into the second flow path F2, and is fixed by pressing the inner tube 101 from the outside in the radial direction to the inside.

Thus, by forming the flow path through which the thermal spray material passes through the double pipe structure surrounded by the flow path through which the heat insulating gas flows, the heat insulating gas flowing through the second flow path F2 serves as a heat insulating layer. For this reason, the temperature of the wall surface (the temperature of the inner tube 101) constituting the first flow path F1 is equal to the temperature of the outer circumference of the second flow path F2 (the inner circumference of the cathode C and the inner circumference of the second cylindrical portion 102d). Temperature). For this reason, even if the thermal spray material contacts the wall surface of the first flow path F1, the rate of adhesion can be significantly reduced. For this reason, it is possible to avoid poor melting caused by clogging of the thermal spraying gun 1 with the thermal spray material, and it is possible to greatly increase the time until the clogging occurs.

<Flow velocity distribution>
As described above, the sprayed material does not adhere to the cathode C and the second cylindrical portion 102d due to the double tube structure of the embodiment, and the sprayed material adheres to the inner tube 101 due to the effect of suppressing the temperature rise of the insulating gas. It can be greatly reduced. Furthermore, the thermal spray gun 1 according to the embodiment can also suppress the adhesion of the thermal spray material to the anode A due to the effect of the heat insulating gas.

It is known that in order to generate a stable plasma flame, the flow velocity distribution at the outlet (jet port) of the anode A should be such that the flow velocity outside the axis is larger. By increasing the flow rate on the outside, the adhesion of the sprayed material to the wall surface of the anode A can be further suppressed.

As described above, in the thermal spray gun 1 according to the embodiment, in addition to the first flow path F1 through which the thermal spray material flows, the second flow path F2 through which the heat insulating gas flows is provided to extend in the axial direction. Therefore, on the downstream side of the cathode C, the thermal spray material (and the working gas), the carrier gas supplied via the spacer 203, and the adiabatic gas are sent out toward the injection port. FIG. 7A is a diagram illustrating an example of a flow velocity distribution in the thermal spray gun 1 according to the embodiment.

As shown in FIG. 7A, in the thermal spray gun 1, in addition to the carrier gas delivered between the cathode C and the anode A, the heat insulating gas is delivered via the second flow path F2. For this reason, the heat insulating gas and the carrier gas are mixed on the downstream side of the cathode C, and the flow velocity radially outside the axis at the injection port of the anode A is increased.

On the other hand, FIG. 7B is a diagram illustrating an example of a flow velocity distribution in a thermal spraying gun having no double tube structure according to the embodiment. As shown in FIG. 7B, even when the structure does not have the double pipe structure, the flow velocity distribution at the injection port of the anode A is larger than the flow velocity at the radially outer side than the axial center due to the introduction of the carrier gas. Has become. However, compared to the embodiment shown in FIG. 7A, the radially outer flow velocity is smaller in the flow velocity distribution of FIG. 7B because there is no increase in the flow velocity due to the insulating gas. As described above, according to the double-pipe structure according to the embodiment, by changing the flow velocity distribution in the injection port of the anode A to a more preferable state, it is preferable to further suppress the adhesion of the sprayed material to the wall surface of the anode A. The effect is obtained.

<Modification>
<Position of adjustment screw 104>
It is preferable that the position where the horizontal hole for screwing the adjustment screw 104 is formed be as downstream as possible in order to stably hold the inner tube 101. Further, by fixing the inner tube 101 on the downstream side, disturbance of the flow of the thermal spray material near the cathode C can be suppressed, and the quality of the thermal spray coating can be stabilized. However, from the viewpoint of suppressing heat transfer to the inner tube 101 via the adjustment screw 104 attached to the side hole, it is preferable to form the side hole as far as possible from the cathode C where the temperature becomes high. Therefore, it is preferable to appropriately adjust the position where the lateral hole is formed according to the material and length of the inner tube 101, the material of the adjusting screw 104, and the like.

<Structure of heat insulating gas flow path>
The position where the horizontal hole 110 for inserting the heat-insulating gas is formed can also be changed according to the length and material of the inner tube 101. In the example of FIG. 2, the side hole 110 is provided in the first cylindrical portion 102c, but the present invention is not limited to this, and the side hole 110 may be provided further upstream or downstream.

<Others>
Further, the inner diameter and outer diameter of the cathode C, the inner diameter, the outer diameter and the thickness of the inner tube 101, the inner diameter and the outer diameter of the anode A, and the like can be appropriately changed according to the material to be sprayed.

種類 In addition, the type of thermal spray material used in thermal spray gun 1 is not particularly limited.

<Effects of Embodiment>
As described above, the thermal spraying apparatus 1000 according to the embodiment includes the cathode C, the anode A, and the inner tube 101. The cathode C has a substantially cylindrical shape, and a flow path through which the thermal spray material passes is formed along the axis. The anode A is arranged to face the downstream end of the cathode C, and generates plasma with the cathode C by arc discharge. The inner tube 101 is arranged so that the axis of the cathode C and the axis of the anode A substantially coincide with each other, and forms at least two flow paths F1 and F2 in the cathode C. At least two flow paths F1 and F2 formed by the inner pipe 101 include a first flow path F1 that allows the thermal spray material to pass through the inner pipe 101 along the axis of the cathode C. Further, at least two flow paths F1 and F2 formed by the inner pipe 101 are formed outside the inner pipe 101 on the radial outside of the first flow path F1, and at least a part of the first flow path F1 is surrounded by the cathode C. And a second flow path F2 through which the fluid flows. As described above, by providing the flow path through which the heat-insulating gas flows outside the flow path through which the thermal spray material flows, the thermal spray performance of the thermal spraying apparatus 1000 can be improved. That is, an increase in the temperature of the inner tube 101 is suppressed as compared with the temperature of the cathode C, and even when the sprayed material comes into contact with the inner tube 101, it can be prevented from adhering as it is. For this reason, it is possible to suppress a decrease in processing efficiency due to the deposition of the thermal spray material in the thermal spray gun 1.

Further, in one embodiment to be disclosed, the thermal spraying apparatus 1000 includes a first supply unit (thermal spray material supply unit 2) for supplying a thermal spray material to the first flow path F1, and a thermal insulating gas in the second flow path F2. And a third supply unit (a carrier gas supply unit 4) for supplying a carrier gas between the downstream end of the cathode C and the anode A. May be provided. Further, the thermal spraying apparatus 1000 controls the supply amounts from the first to third supply units independently so that the flow velocity distribution of the gas discharged to the downstream side of the anode A is outside the anode A in the radial direction. The control unit 13 adjusts the flow velocity so as to be a flow velocity distribution larger than the flow velocity at the center in the radial direction. Therefore, it is possible to prevent not only the adhesion and deposition of the thermal spray material on the surface of the cathode C but also the adhesion and deposition of the thermal spray material on the surface of the anode A. Further, the spraying quality can be improved.

Further, in one disclosed embodiment, the thermal spraying apparatus 1000 is disposed on the upstream side of the cathode C, accommodates at least a part of the inner pipe 101, and accommodates the transport pipe section 100 for transporting the thermal spray material, and accommodates the cathode C. And an anode unit 300 that accommodates the anode A. The transport tube 100 is configured to be detachable independently, and the cathode C can be independently replaced by removing the transport tube 100. Therefore, replacement and maintenance of the cathode C can be easily performed.

In addition, in one disclosed embodiment, the anode unit 300 is configured to be independently detachable, and by removing the anode unit 300, the anode A can be replaced independently. Therefore, replacement and maintenance of the anode A can be easily performed.

In one embodiment to be disclosed, the transport pipe 100 is configured to fix the inner pipe 101 to the transport pipe 100 at the upstream end of the transport pipe 100 with the inner pipe 101 housed in a fixed position. 1 locking portion (holding flange 103, flange 102a, screw, O-ring). Therefore, the inner pipe 101 can be easily fixed to the transport pipe section 100. Further, the contact between the inner tube 101 and the cathode C can be suppressed to suppress the temperature rise of the inner tube 101, and the adhesion and deposition of the thermal spray material on the inner tube 101 can be prevented.

In addition, in one disclosed embodiment, the transport pipe section 100 further includes a second locking section (adjustment screw 104) that fixes the inner pipe 101 downstream of the first locking section. Therefore, the thermal spraying apparatus 1000 can fix the inner tube 101 more stably. Further, the contact between the inner tube 101 and the cathode C can be suppressed to suppress the temperature rise of the inner tube 101, and the adhesion and deposition of the thermal spray material on the inner tube 101 can be prevented.

In one disclosed embodiment, at least a part of the second locking portion is disposed in the second flow path F2. By arranging the second locking portion connecting the inner tube 101 and the other part of the thermal spraying apparatus 1000 in the second flow path F2 through which the heat-insulating gas flows, the temperature of the inner tube 101 can be further increased. Can be suppressed.

Further, in one disclosed embodiment, the transport pipe section 100 has a main body section 102 having a cylindrical space for accommodating the inner pipe 101, and the cylindrical space is fitted with the inner pipe 101 on the upstream side. It may have a matching dimension and have a larger diameter on the downstream side than on the upstream side. By configuring the main body 102 in this way, by inserting the inner tube 101 through the main body 102, two flow paths can be easily formed in the cathode C. Therefore, the thermal spraying performance of the thermal spraying apparatus 1000 can be improved with a simple configuration.

実施 The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. Indeed, the embodiments described above can be embodied in various forms. Further, the above embodiments may be omitted, replaced, or modified in various forms without departing from the scope and spirit of the appended claims.

1000 Thermal spraying apparatus 1 Thermal spray gun 2 Thermal spray material supply unit 3 Thermal insulation gas supply unit 4 Carrier gas supply unit 13 Control unit 14 Storage unit 100 Transport pipe unit 101 Inner pipe 102 Main body 102a Flange 102b Body detail 102c First cylindrical part 102d Second Cylindrical part 103 Holding flange 104 Adjusting screw 107 O-ring 110 Side hole 111 Screw part 200 Cathode part 201 Body part

201a Screw part

201b Projection part 202 Cover 203 Spacer 206 Space 207 Pipe line 211 Hole 212 Side hole 213 Screw part 300 Anode part A Anode A1 Tube portion A2 Projection portion C Cathode C1 Tube portion C2 Projection portion F1 First flow path F2 Second flow path W Object

Claims

A substantially cylindrical cathode in which a flow path through which the sprayed material passes is formed along the axis,
An anode that is arranged to face a downstream end of the cathode and generates plasma by arc discharge between the cathode and the anode;
An inner tube arranged so that the axis of the cathode and the axis of the anode substantially coincide with each other, and forming at least two flow paths in the cathode;
With
The inner tube is
A first flow path through which the sprayed material passes along the axis of the cathode in the inner tube;
Outside the inner tube, a second flow path formed radially outside of the first flow path and at least partially surrounded by the cathode, and passing a heat-insulating gas;
A thermal spraying device for forming the at least two flow paths.
A first supply unit that supplies a thermal spray material to the first flow path;
A second supply unit that supplies a heat-insulating gas to the second flow path;
A third supply unit that supplies a carrier gas between the downstream end of the cathode and the anode;
By independently controlling the supply amounts from the first to third supply units, the flow velocity distribution of the gas discharged to the downstream side of the anode is such that the flow velocity on the radially outer side of the anode is radially centered. A control unit for adjusting the flow velocity distribution to be larger than the flow velocity,
The thermal spraying apparatus according to claim 1, further comprising:
A transport pipe portion that is disposed on the upstream side of the cathode and accommodates at least a part of the inner pipe, and transports the thermal spray material.
A cathode section for housing the cathode,
An anode section that houses the anode;
With
The transport tube portion is configured to be independently detachable, and the cathode is independently exchangeable by removing the transport tube portion.
The thermal spraying device according to claim 1.
A transport pipe portion that is disposed on the upstream side of the cathode and accommodates at least a part of the inner pipe, and transports the thermal spray material.
A cathode section for housing the cathode,
An anode section that houses the anode;
With
The anode unit is configured to be independently detachable, and the anode is independently replaceable by removing the anode unit.
The thermal spraying device according to claim 1.
A transport pipe portion that is disposed on the upstream side of the cathode and accommodates at least a part of the inner pipe, and transports the thermal spray material.
A cathode section for housing the cathode,
An anode section that houses the anode;
With
The transport tube portion is configured to be independently detachable, the cathode can be independently replaced by removing the transport tube portion,
The anode unit is configured to be independently detachable, and the anode is independently replaceable by removing the anode unit.
The thermal spraying device according to claim 1.
The transport pipe section,
6. The apparatus according to claim 3, further comprising a first locking portion that fixes the inner pipe to the transport pipe at an upstream end of the transport pipe in a state where the inner pipe is housed in a fixed position. 7. 2. The thermal spraying apparatus according to claim 1.
The transport pipe section,
The thermal spraying device according to claim 6, further comprising a second locking portion that fixes the inner pipe on a downstream side of the first locking portion.
The thermal spraying apparatus according to claim 7, wherein at least a part of the second locking portion is disposed in the second flow path.
The transport pipe section,
A main body having a cylindrical space accommodating the inner tube, the cylindrical space having a fitting size with the inner tube on the upstream side, and having a larger diameter on the downstream side than on the upstream side; The thermal spraying device according to any one of claims 6 to 8.