JP2012193431A - Plasma spraying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma spraying device in which conductive wire of metal or the like and the powder of ceramic or the like can be used as a thermal spraying material.SOLUTION: In the plasma spraying device, a plurality of jackets 11, 15, 19 having release ports 11a, 15a, 19a are continuously connected to the surface of the shaft in a cathode nozzle 3 having a cathode 2 in series via insulating materials 4, 12, 16; the jacket 19 at the top is used as a conductive wire spraying jacket to be fed with conductive wire of metal or the like; the other jackets are used as jackets for powder spraying; and the jackets for powder spraying and the jacket for conductive wire spraying are connected detachably, and further, while a powder feeding means 28 of feeding the powder of ceramics or the like is provided.

Description

  The present invention melts a material such as metal or ceramics by a large current flowing in a gas, a so-called arc, or plasma generated at a high temperature of around 10,000 ° C., and sprays it on an object to be processed. More specifically, the present invention relates to a plasma spraying apparatus that can use a conductive wire such as metal and a powder such as ceramic as a spraying material.

  Conventional plasma spraying apparatuses include those using a conductive wire such as metal as a spraying material and those using powder such as ceramic. FIG. 7 shows a main part of a conventional general-purpose plasma spraying apparatus using powder as a spraying material.

  In FIG. 7, a jacket 11 having a discharge port on the axis of a cathode nozzle 3 having a cathode 2 and an insulator 4 are concentrically held, and a plasma gas 6 is supplied from a plasma gas inlet / outlet 5 provided in the insulator 4. Are fed to protect the cathode 2. The negative terminal of the main power supply 7 is connected to the cathode 2, and the positive terminal of the main power supply 7 is connected to the jacket 11 through the switch means 8, and these constitute the spray gun (plasma spray apparatus) 1 as a whole. is doing.

  In FIG. 7, when an inert gas such as argon is flowed from the plasma gas inlet 5 as the plasma gas 6, the switch means 8 is closed and applied between the cathode 2 and the jacket 11 by the high frequency of the main power source 7. A plasma arc 22 is formed from the tip of 2 toward the discharge port of the mantle 11, whereby the plasma gas 6 is heated and is emitted from the tip of the mantle 11 as a plasma arc 22.

  At this time, the powder thermal spray material 29 conveyed by the material feed pipe 28 provided on the thermal spray gun 1 is fed into the high temperature plasma frame 23 in a direction crossing the plasma arc 22 axis. Therefore, the thermal spray material 29 becomes molten particles 24 due to the heat of the plasma flame 23, travels toward the base material (spray material) 27 without spreading so much while being accompanied by the plasma flame 23, and the molten particles 24. Collides with the base material 27 to form a sprayed coating 26.

  In the above description, the inner surfaces of the cathode nozzle 3 and the outer mantle 4 are usually double structures, and the inside is cooled by circulation of water or the like, but this is omitted and not shown. In the following description, each corresponding cooling system is omitted.

  FIG. 8 shows a main part of a conventional general-purpose plasma spraying apparatus using a conductive wire as a spraying material. In FIG. 8, the outer casing 11 and the second outer casing 15 having an emission port on the axis of the cathode nozzle 3 having the cathode 2, and the insulator 4 and the insulator 12 are concentrically held.

  At this time, the insulator 4 is provided with a plasma gas inlet 5, and the cathode 2 is protected by feeding the plasma gas 6 from the inlet 5. Further, the insulator 12 is provided with a second plasma gas inlet 13 through which the second plasma gas 14 is fed.

  The negative terminal of the main power supply 7 is connected to the cathode 2, and the positive terminal of the main power supply 7 is connected to the outer sheath 11 via the switch means 8 and the conductive wire 21 via the switch means 10, and these are the whole. As shown in FIG.

  In FIG. 8, when an inert gas such as argon is flowed from the plasma gas inlet 5 as the plasma gas 6, the switch means 8 is closed and applied between the cathode 2 and the jacket 11 by the high frequency of the main power source 7. A plasma arc 22 is formed from the tip of 2 toward the discharge port of the mantle 11, whereby the plasma gas 6 is heated and is emitted from the tip of the mantle 11 as a plasma arc 22.

  Next, by closing the switch means 10 and opening the switch means 8, the anode point 22 of the plasma arc 25 moves from the jacket 11 to the conductive wire 21, and the conductive wire is instantaneously transferred by the high-temperature plasma arc 25. 21 melts and is blown by a large amount of the second plasma gas 14 supplied from the second plasma gas inlet 13 provided in the insulator 12 to become fine molten particles 24, and is accompanied by the plasma frame 23, It proceeds toward the base material (spray material) 27 without spreading, and the molten particles 24 collide with the base material 27 to form a sprayed coating 26.

  The first problem to be solved by the present invention is that, in the conventional plasma spraying apparatus, first, the spraying material to be used is roughly classified into powder or wire (wire), and when both are desired to be used, the respective plasma spraying is performed. Equipment is required, initial cost is increased, and storage space is increased.

  In view of the above circumstances, an object of the present invention is to use a wire as a thermal spray material as a basic configuration, and to use a powder as a thermal spray material by removing and replacing some parts.

  In the present invention, a plurality of jackets having discharge ports are arranged in series via an insulator on the axis of a cathode nozzle having a cathode, and the leading jacket is supplied with a conductive wire such as metal. A powder wire-spraying mantle, a powder-spraying mantle, and the powder-spraying mantle and the conductive wire-spraying mantle are detachably connected to each other and supply powder such as ceramics. A supply means is provided.

  The conductive wire of the present invention is supplied to the inside of the discharge port of the outer jacket for conductive wire spraying or the vicinity of the outside of the discharge port through a wire supply means. The wire supply means of the present invention has a function of pulling and pushing the conductive wire. The plurality of mantles according to the present invention are characterized by comprising a first mantle and a second mantle which are powder thermal spraying mantles and a third mantle which is a conductive wire thermal mantle.

  The outer sheath of the present invention is characterized in that a swirl flow forming hole for swirling the plasma gas is formed. The discharge port of the powder spraying jacket of the present invention is formed by an accelerator nozzle. The accelerator nozzle of the present invention is characterized in that it is attached to and detached from the powder spray jacket.

  Since the present invention is configured as described above, a conductive wire or powder can be used as the thermal spray material by attaching and detaching the conductive wire thermal spray jacket to the powder thermal spray jacket. For this reason, since both of the thermal spray materials can be used in one unit, the storage space can be reduced compared to the conventional example.

  The main application of this plasma spraying device is on-site thermal spraying, but the plasma spraying device, which has been expensive and difficult to construct on site, has been simplified by the present invention to reduce the initial cost and running cost. The system configuration can be made as compact as possible, and can be easily moved and moved.

It is a longitudinal section showing a 1st embodiment of the present invention. It is sectional drawing which shows the use condition of 1st Embodiment. It is the sectional view on the ab line of FIG. It is an enlarged front view of a wire supply means. It is a longitudinal cross-sectional view which shows 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows 3rd Embodiment of this invention. It is a front view which shows a 1st prior art example. It is a front view which shows the 2nd prior art example.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a main part of a plasma spraying apparatus using, as a thermal spray material, a wire that conducts electricity such as metal, carbon, cermet, etc., that is, a conductive wire.

  In FIG. 1, a first outer jacket 11, a second outer jacket 15 and a third outer jacket 19 having discharge ports on the axis of a cathode nozzle 3 having a cathode 2, an insulator 4 having a swirling gas forming means 30, and an insulator 12. And the insulator 16 is concentrically held. The third mantle 19 is an outer mantle connected to the second mantle 15 when a conductive wire is used as the thermal spray material, and can be called a so-called “conductive wire thermal mantle”. The first and second mantles 11 and 15 are mantles that are used when powder such as ceramic is used as the thermal spray material, and can be referred to as so-called “powder for thermal spraying”. The second mantle 15 and the third mantle 19 are connected by attaching / detaching means (not shown) such as screws.

  As shown in FIG. 3, the plasma gas 6 is first fed into the gas annular chamber 31 from the plasma gas inlet 5, and a single swirl flow forming hole 32 formed in the insulator 4 or a plurality of equally arranged holes. Through the swirl flow forming hole 32, the inner wall 33 of the insulator 4 is fed as shown by an arrow 34 so as to swivel. Similarly, the second plasma gas 14 and the third plasma gas 18 are also fed to turn the inner walls of the insulator 12 and the insulator 16, respectively.

  The negative terminal of the main power supply 7 is connected to the cathode 2, the positive terminal of the main power supply 7 is connected to the first outer jacket 11 via the switch means 8, the second outer jacket 15 via the switch means 9, and the switch means. 10 is connected to a third mantle 19 through which a spray gun (plasma spraying device) 1 is configured as a whole.

  In FIG. 1, when an inert gas such as argon is flowed from the plasma gas inlet 5 as the plasma gas 6, the switch means 8 is closed and applied between the cathode 2 and the jacket 11 by the high frequency of the main power source 7. A plasma arc 22 is formed from the tip of 2 toward the discharge port of the first mantle 11, whereby the plasma gas 6 is heated, and the plasma arc 22 is discharged from the discharge port (constriction hole) 11 a at the tip of the mantle 11. Is done.

  Next, by closing the switch means 9 and opening the switch means 8, the anode point 22 of the plasma arc 25 moves from the first mantle 4 to the second mantle 15, and the second plasma provided on the insulator 12. Due to the second plasma gas 14 fed from the gas inlet 13, the plasma arc further extends through the discharge port 15a.

  Finally, by closing the switch means 10 and opening the switch means 9, the anode point 22 passes through the third mantle 19 and moves to the tip of the conductive wire 21 exposed inside the discharge port 19a, The conductive wire 21 is melted instantaneously by the high-temperature plasma arc 25.

  By having two or more anodes in this way and shifting the anode point, the potential difference from the cathode 2 to the anode (coats 11, 15 and 21) is increased by 100 V or more, and the wear of the electrodes is reduced with high voltage and low current characteristics. can do. Further, since the insulators 4, 12, and 16 are provided with the swirling flow forming means (the swirling flow forming hole 32), a strong swirling flow is formed around the plasma arc. Therefore, the thermal pinch effect (thermal concentration) of plasma can be enhanced and the cooling loss of the thermal spray torch 1 can be reduced.

  The molten sprayed material is blown by a large amount of the third plasma gas 18 fed from the third plasma gas inlet 17 provided in the insulator 16 to become fine molten particles 24 and is accompanied by the plasma frame 23. However, it proceeds toward the base material (spray material) 27 without spreading so much, and the molten particles 24 collide with the base material 27 to form a sprayed coating 26.

  At this time, the conductive wire 21 is supplied from the wire supply means 20 at an arbitrary constant speed. As shown in FIG. 4, the wire supply means 20 is configured to drive and drive the wire pull wheel gear 37 and the wire push wheel gear 39 by one drive motor 35 in order to securely grasp and supply the wire. The wire 21 is provided with a pull pinch roll 38 and a push pinch roll 40 so as not to slip. In the following description, all the corresponding wire supply means 20 are omitted.

  Next, the case where a powder material is used as the thermal spray material will be described. FIG. 2 illustrates the main part of the plasma spraying apparatus when a powder such as a ceramic material is used as the spraying material. Basically, the plasma spraying apparatus 1 of FIG. The wire spray jacket 19 and the insulator 16 are simply removed.

  A powder material 29 is fed from a powder material feed pipe 28 provided on the plasma spraying apparatus 1 into a high-temperature plasma frame 23 discharged from the discharge port 15a of the second mantle 15, and the powder material 29 is melted. The molten particles 24 become entrained by the plasma frame 23 and travel toward the base material (spray material) 27 without spreading so much. The molten particles 24 collide with the base material 27 and cause the sprayed coating 26 to flow. Form.

  In this way, the powder material can be easily sprayed simply by removing the outer jacket for conductive wire spraying. Therefore, since one plasma torch 1 can use conductive wire such as metal and powder such as ceramic as the spraying material, it can be simplified and the initial cost and running cost can be reduced, and maintenance and inspection are also possible. It becomes easy.

  A second embodiment of the present invention will be described with reference to FIG. 5. The same reference numerals as those in FIGS. 1 to 4 have the same names and functions. The difference from the first embodiment is the power supply and wire supply means. That is, in this embodiment, the conductive wire 21 is not supplied from the inner wall of the third mantle 19, but is supplied from the outside of the plasma spraying apparatus 1 to the vicinity of the outside of the discharge port 19a of the third mantle 19, The operation of forming the film 26 is the same as in the first embodiment.

  Further, when the melting point of the conductive wire 21 is high, or when the diameter of the conductive wire 21 is increased, or when it is desired to increase the spraying amount by increasing the supply speed, the auxiliary power source 42 can be further increased to increase the spraying output. It is a system.

  A third embodiment of the present invention will be described with reference to FIG. 6. The same reference numerals as those in FIGS. 1 to 4 have the same names and functions. In this embodiment, when a dense sprayed coating 26 is required as a main purpose, an accelerator nozzle 41 that can be attached to and detached from the second jacket 15 is provided to accelerate the molten particles 23 in order to meet this need. . The inner wall of the discharge portion 41a of the accelerator nozzle 41 receives the anode point 25 of the plasma arc 22 and has a powerful water cooling means (not shown).

  The accelerator nozzle 41 is located at the discharge port (discharge portion) of the second mantle 15 and the pressure in the thermal spraying torch 1 changes as the diameter and length of the discharge portion 41a change, resulting in plasma. The speed can be changed. For example, in an A accelerator nozzle (for example, 10 mm in length) and a B accelerator nozzle (for example, 20 mm in length) having the same inner diameter and different lengths, the B accelerator nozzle naturally increases the internal pressure and increases the plasma velocity. The potential difference increases and the output increases. For this reason, the load on the accelerator nozzle B is increased, so that further cooling enhancement is required. The accelerator nozzle 41 must have an optimal discharge port diameter (discharge diameter) and discharge port length (discharge length) depending on the application.

DESCRIPTION OF SYMBOLS 1 Thermal spray gun 2 Cathode 3 Cathode nozzle 4 Insulator 6 Plasma gas 11 First mantle 11a Outlet 12 Insulator 14 Second plasma gas 15 Second mantle 16 Insulator 18 Third plasma gas 19 Third mantle 19a Outlet 20 Wire Supply means 21 Conductive wire 22 Plasma arc 23 Plasma frame 28 Material material supply pipe 29 Powder material 30 Swirl flow gas formation means 32 Swirl flow formation hole 41 Accel nozzle 41a Discharge port

Claims (7)

On the axis of a cathode nozzle having a cathode, a plurality of mantles having discharge ports are connected in series via an insulator,
The top jacket is a conductive wire spray jacket to which conductive wires such as metal are supplied, and the other jacket is a powder spray jacket.
A plasma spraying apparatus characterized in that the powder spraying jacket and the conductive wire spraying jacket are detachably connected and provided with powder supply means for supplying powder such as ceramics.   The tip of the conductive wire is supplied to the inside of the discharge port of the outer jacket for conductive wire spraying or the vicinity of the outside of the discharge port via a wire supply means. Plasma spraying device.   The plasma spraying apparatus according to claim 1, wherein the wire supply means has a function of pulling and pushing the conductive wire.   2. The plasma spraying apparatus according to claim 1, wherein the plurality of jackets include a first jacket and a second jacket that are powder coating jackets, and a third jacket that is a conductive wire spray jacket. .   2. The plasma spraying apparatus according to claim 1, wherein a swirl flow forming hole for swirling the plasma gas is formed in the outer insulator.   The plasma spraying apparatus according to claim 4, wherein the discharge port of the powder spraying jacket is formed by an accelerator nozzle. 7. The plasma spraying apparatus according to claim 6, wherein the accelerator nozzle is detachably provided on the powder spraying jacket.

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