JP2022090327A - Thermal spray gun and thermal spray system including the same - Google Patents

Abstract

To provide a thermal spray gun having a structure suitable for controlling the level of microfabrication of a wire to be melted.SOLUTION: A thermal spray gun 2 includes: a gun main body 21 having a pair of wires W inserted in the inside; a nozzle 24 provided in the tip of the gun main body 21 and having an internal space; and a pair of power supply chips 22 arranged in the internal space and having an open hole for inserting the pair of wires. The nozzle 24 includes a first outlet having a gas jet hole 242 facing a first direction x extending toward a tip side from a base end side in a tip and for blowing a first compressed gas toward the internal space; and a second outlet 263 coming closer to the gas jet hole 242 than the first outlet in the first direction x and for blowing a second compressed gas toward the internal space.SELECTED DRAWING: Figure 5

Description

The present invention relates to a thermal spray gun for forming a thermal spray coating on an object to be sprayed, and a thermal spraying system including the same.

In arc spraying performed using a thermal spraying device, a pair of wires made of a metal wire is fed to a thermal spray gun and the wires are melted by arc discharge. The melted wire is sprayed onto the sprayed object by a gas flow (compressed gas) ejected from the nozzle, and a thermal spray coating is formed on the surface of the sprayed object. Patent Document 1 describes a thermal spray gun for performing such arc spraying.

As described in Patent Document 1, in the conventional spraying gun, the pair of wires fed to the spraying gun is sent out via the pair of feeding tips provided at the tip of the spraying gun. The nozzle is provided at the tip of the thermal spray gun and has a predetermined internal space. The pair of feeding chips are arranged in the internal space of the nozzle. The wire is inserted into a through hole formed in the feeding chip, and is internally contacted to be energized. The pair of wires are sent out through the pair of feeding chips so as to be gradually close to each other, and the tips are short-circuited and melted by the heat of the arc generated. The gas flow ejected from the gas ejection hole at the tip of the nozzle collides with the droplet (molten metal), and the molten metal is sprayed onto the sprayed object while being miniaturized. Here, by making the molten metal finer, a dense thermal spray coating is formed.

In the past, for example, in order to form a dense thermal spray coating, it was generally practiced to adjust the thermal spraying conditions such as the wire feeding amount (that is, the feeding speed) and the arc voltage. However, if the feeding amount of the wire is changed, the melting amount of the wire per unit time changes, so that the construction time and the consumption amount of the wire vary. Then, the sprayed coating becomes non-uniform, and the quality of the sprayed coating deteriorates.

Japanese Unexamined Patent Publication No. 2006-241543

The present invention has been conceived under such circumstances, and a main object of the present invention is to provide a thermal spray gun having a structure suitable for controlling the degree of miniaturization of the wire to be melted.

In order to solve the above problems, the following technical means are adopted in the present invention.

The thermal spraying gun provided by the first aspect of the present invention has a gun body through which a pair of wires is inserted, a nozzle provided at the tip of the gun body and having an internal space, and a nozzle arranged in the internal space. A pair of feeding chips having a through hole for inserting the pair of wires, and the nozzle has a gas ejection hole at the tip portion facing a first direction, which is a direction from the proximal end side to the distal end side. Then, the first discharge port for blowing out the first compressed gas toward the internal space and the gas ejection hole closer to the gas ejection hole in the first direction than the first discharge port, and the first toward the internal space. 2 It has a second discharge port for blowing out compressed gas.

In a preferred embodiment, the cross-sectional area of the second discharge port is smaller than the cross-sectional area of the first discharge port.

In a preferred embodiment, the second ejection port is provided on each of the pair of feeding chips.

In a preferred embodiment, the inner surface shape of the nozzle has a smaller cross-sectional area in the in-plane direction perpendicular to the axis of the nozzle toward the first direction.

In a preferred embodiment, the second discharge port faces the gas ejection hole.

The thermal spraying system provided by the second aspect of the present invention includes a thermal spraying gun according to the first aspect of the present invention, and a first gas supply means for constantly supplying the first compressed gas to the thermal spraying gun. A second gas supply means for intermittently supplying the second compressed gas to the thermal spray gun is provided.

In a preferred embodiment, the first compressed gas is air and the second compressed gas is argon gas.

According to the present invention, a first discharge port for blowing out the first compressed gas in the internal space of the nozzle and a second discharge port for blowing out the second compressed gas in the internal space of the nozzle are provided. The second discharge port is located closer to the gas ejection hole in the first direction than the first discharge port. The first compressed gas is constantly supplied to the thermal spray gun by the first gas supply means, and the first compressed gas is constantly blown out from the first discharge port into the internal space of the nozzle. Further, the second compressed gas is intermittently supplied to the thermal spray gun by the second gas supply means, and the second compressed gas is intermittently blown out from the second discharge port into the internal space of the nozzle. According to such a configuration, a gas in which a second compressed gas that is intermittently supplied in addition to the first compressed gas that is constantly supplied is ejected from the gas ejection hole, and the molten metal of the wire becomes finer. It is possible to form a dense thermal spray coating.

Other features and advantages of the invention will be more apparent by the detailed description given below with reference to the accompanying drawings.

It is a schematic block diagram which shows an example of the thermal spraying system provided with the thermal spraying gun which concerns on this invention. An example of a thermal spraying gun according to the present invention is shown, and is a view seen from the tip side of the thermal spraying gun. FIG. 3 is a partial cross-sectional view taken along the line III-III of FIG. FIG. 2 is a partial cross-sectional view taken along the line IV-IV of FIG. It is a partially enlarged view of FIG. It is a partially enlarged view of FIG. Another example of the thermal spraying gun according to the present invention is shown, and the cross-sectional view is the same as in FIG.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a thermal spraying system including a thermal spraying gun according to the present invention. FIG. 2 shows an example of a thermal spraying gun according to the present invention, and is a view seen from the tip side of the thermal spraying gun. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG.

The thermal spraying system A1 shown in FIG. 1 is for performing thermal spraying on an object to be sprayed (not shown), and includes a power supply unit 1, a thermal spray gun 2, a first gas supply means 3A, and a second gas supply means 3B. And a pair of push-side wire feeders 4. The thermal spraying gun 2 according to the present embodiment has a form of a manual gun for the operator to grasp and perform the thermal spraying work.

The power supply unit 1 supplies electric power to the thermal spray gun 2. The electric power from the power supply unit 1 is controlled by a constant voltage and is supplied to the thermal spray gun 2 via the power supply cable 11 and is supplied to the power supply chip 22 via the power supply member 213 described later.

The push-side wire feeder 4 includes, for example, a guide roller, a feeder roller, and a motor (all not shown), and sends out the wire W wound on the wire reel 5 toward the thermal spray gun 2. .. The wire reel 5 indicates a device in which the wire W is housed. For example, the wire reel 5 has a form in which the wire W is wound around a reel that can rotate around an axis extending in a horizontally direction, and the wire W is unwound while rotating. be able to. The wire W unwound from the wire reel 5 is guided by, for example, the push-side guide liner 8 to reach the thermal spray gun 2. The sprayed voltage supplied from the power supply unit 1 and the feeding speed of the wire W by the push-side wire feeder 4 are set by, for example, the remote controller 6.

The first gas supply means 3A supplies the first compressed gas to the thermal spray gun 2. The first gas supply means 3A includes, for example, a first gas supply source 31, a first gas pipe 33, and a first gas adjusting unit 35. In the present embodiment, the first compressed gas is air, and the first gas supply source 31 is a compressor. The first gas pipe 33 is a gas flow path for sending the first compressed gas from the first gas supply source 31 to the thermal spray gun 2, and is composed of, for example, a gas hose. The first gas adjusting unit 35 includes, for example, a solenoid valve and a flow meter. In the present embodiment, the flow rate of the compressed air (first compressed gas) ejected from the compressor (first gas supply source 31) is controlled by the first gas adjusting unit 35, and the compressed air is constantly sent to the thermal spray gun 2. Be done.

The second gas supply means 3B supplies the second compressed gas to the thermal spray gun 2. In the present embodiment, the second compressed gas is a gas of a different type from the above-mentioned first compressed gas. The second gas supply means 3B includes, for example, a second gas supply source 32, a second gas pipe 34, and a second gas adjusting unit 36. In the present embodiment, the second compressed gas is an argon gas, and the second gas supply source 32 is a gas cylinder that stores the argon gas in a high pressure state. The second gas pipe 34 is a gas flow path for sending the second compressed gas from the second gas supply source 32 to the thermal spray gun 2, and is composed of, for example, a gas hose. The second gas adjusting unit 36 includes, for example, a solenoid valve and a flow meter. In the present embodiment, the solenoid valve is appropriately opened and closed and the opening degree is adjusted during the thermal spraying operation. In the present embodiment, the flow rate of the argon gas (second compressed gas) ejected from the gas cylinder (second gas supply source 32) is controlled by the second gas adjusting unit 36, and is intermittently sent to the thermal spray gun 2. Be done. As the second compressed gas, another inert gas such as helium gas may be used instead of the argon gas. Further, when performing the thermal spraying work, the first gas adjusting unit 35 and the second gas adjusting unit 36 (solenoid valve) are opened and closed and the opening degree is adjusted by a gas control device (not shown).

As shown in FIGS. 2 to 4, the thermal spray gun 2 includes a gun body 21, a pair of feeding tips 22, a pair of guide liners 23, a nozzle 24, a first gas supply path 25, and a second gas supply. It has a road 26 and. The gun body 21 has a cylindrical shape, and the wire W fed by the push-side wire feeder 4 can pass through the inside of the gun body 21. A pair of pull-side wire feeders 9 are attached to the gun body 21. The pull-side wire feeder 9 feeds the wire W guided by the push-side guide liner 8 to the tip end side of the gun body 21. A liner holding member 211 is attached to the tip of the gun body 21. An insulating member 212 is also attached to the tip of the gun body 21.

The feeding chip 22 is attached to the feeding member 213. The feeding member 213 is provided in pairs so as to correspond to the pair of feeding chips 22. More specifically, a female screw is formed at the tip of the feeding member 213, and a male screw is formed at the base end of the feeding tip 22. By screwing the male screw into the female screw, the feeding tip 22 Is attached to the feeding member 213. In this way, the feeding tip 22 is detachably provided on the tip end side of the gun body 21. The pair of power feeding members 213 are supported by the insulating member 212, and the power feeding members 213 are in an insulated state.

The pair of female threads formed on the pair of feeding members 213 extend at an angle with respect to the axial direction of the gun body 21 (spraying gun 2). Then, as shown in FIGS. 3 and 5, the pair of feeding tips 22 are so close to each other that their central axes O1 are directed toward the direction x (first direction) which is the tip end side of the thermal spray gun 2. .. These central axis lines O1 intersect at a position separated in the direction x from the tip end portion of the nozzle 24, and the intersection is set as an arc point Ox. In the present embodiment, the portion on the tip end side of each feeding tip 22 has a tapered shape whose diameter becomes smaller toward the tip end.

The liner holding member 211 receives one end of the guide liner 23 on the tip side. A through hole 211a for inserting the wire W that has passed through the pull-side wire feeder 9 is formed on the base end side of the liner holding member 211. Further, the feeding tip 22 receives the other end of the guide liner 23 on the proximal end side. A through hole 22a for inserting the wire W that has passed through the guide liner 23 is formed on the tip end side of the feeding chip 22. The inner diameter (diameter) of the through hole 211a of the liner holding member 211 and the through hole 22a of the feeding chip 22 is a dimension corresponding to the thickness of the wire W (the outer diameter dimension of the cross section), and the cross section of the wire W. A little larger than the outer diameter. That is, as the liner holding member 211 and the feeding tip 22, if the thickness of the wire W used is different, the diameters of the through holes 211a and 22a are different accordingly. The thickness (external dimensions) of the wire W used is, for example, 0.8 mm or more.

The guide liner 23 has a flexible tubular shape, and serves to guide the wire W to the feeding tip 22 by inserting the wire W. As the material constituting the guideliner 23, a material having a small sliding resistance of the wire W is preferable. Examples of such a material include synthetic resins such as fluororesins.

As shown in FIGS. 3 and 4, the nozzle 24 is provided at the tip portion of the thermal spray gun 2. The nozzle 24 has an annular shape that surrounds the tips of the pair of feeding chips 22, and the internal space is connected to the first gas supply path 25 and the second gas supply path 26. Further, as shown in FIGS. 5 and 6, in the present embodiment, the nozzle 24 surrounds all the tips of the pair of feeding tips 22 in the in-plane direction perpendicular to the axis CL. The nozzle 24 is made of an insulating material or a non-insulating material as a base material, and the inner surface 241 of the nozzle 24 is coated with an insulating material such as a ceramic material.

In the present embodiment, the inner surface shape of the nozzle 24 has a smaller cross-sectional area in the in-plane direction toward the direction x, and the tip side is narrowed. Further, a gas ejection hole 242 facing the direction x is formed at the tip of the nozzle 24 in the direction x. As an example of the dimensions of the nozzle 24, the inner diameter of the base end of the nozzle 24 is about 50 to 80 mm, the inner diameter of the tip of the nozzle 24 is about 5 to 8 mm, and the inner diameter of the gas ejection hole 242 is about 5 to 8 mm. be. As for the inner surface shape of the nozzle 24, various shapes can be adopted in addition to the shape in which the tip side is narrowed as in the present embodiment.

The first gas supply path 25 is a flow path for supplying the first compressed gas from the gun body 21 side toward the internal space of the nozzle 24. In the present embodiment, the first gas supply path 25 is mainly provided inside the insulating member 212, and the first compressed gas is supplied to the first gas supply path 25 via the first gas pipe 33. .. As shown in FIG. 4, in the present embodiment, the first gas supply path 25 includes two branch flow paths 251 extending in a branched manner and a first discharge port 252. The downstream end of each branch flow path 251 is a first discharge port 252 open to the internal space of the nozzle 24. The first discharge port 252 is an opening for blowing out the first compressed gas into the internal space of the nozzle 24. Each first discharge port 252 faces the direction x.

The second gas supply path 26 is a flow path for supplying the second compressed gas toward the internal space of the nozzle 24. In the present embodiment, the second gas supply path 26 is provided inside the insulating member 212, inside the feeding chip 22, and the like. In the present embodiment, a pair of second gas supply paths 26 are provided corresponding to each of the pair of power feeding chips 22. As shown in FIGS. 3 to 5, in the present embodiment, the second gas supply path 26 includes a main flow path 261, a branch path 262, and a second discharge port 263. The main flow path 261 is formed inside the insulating member 212, and the second compressed gas is supplied to the main flow path 261 via the second gas pipe 34. The main flow path 261 communicates with the space through which the guide liner 23 is passed inside the insulating member 212. The branch path 262 is formed in the feeding chip 22. In the present embodiment, each feeding chip 22 is formed with a pair of branch paths 262. Each of the pair of branch paths 262 leads to the through hole 22a, and is provided on the opposite side of the through hole 22a. Each branch path 262 extends along a straight line parallel to the central axis O1, and the downstream end of each branch path 262 is a second discharge port 263 open to the internal space of the nozzle 24.

The second discharge port 263 is an opening for blowing out the second compressed gas into the internal space of the nozzle 24. The second discharge port 263 is located closer to the gas ejection hole 242 than the first discharge port 252 in the direction x. Each second discharge port 263 faces the gas ejection hole 242.

When the second compressed gas is supplied to the second gas supply path 26, the second compressed gas flows in the order of the main flow path 261, the gap between the feeding member 213 and the guide liner 23, and the through hole 22a. Next, the second compressed gas flows into the branch path 262 and is blown out from the second discharge port 263 into the internal space of the nozzle 24.

As can be understood from FIGS. 5 and 6, in the present embodiment, the cross-sectional area of the second discharge port 263 is smaller than the cross-sectional area of the first discharge port 252. The ratio of the cross-sectional area of the second discharge port 263 to the cross-sectional area of the first discharge port 252 is, for example, about 0.1 to 0.5 times. Further, the ratio of the diameter (inner diameter) of the second discharge port 263 to the diameter of the wire W is, for example, about 0.5 to 1.5 times.

Next, a procedure for performing thermal spraying on the subject to be sprayed using the above-mentioned thermal spray gun 2 and the thermal spraying system A1 will be described.

When performing thermal spraying work using the thermal spraying system A1, when the operator presses the start switch 7 provided on the thermal spraying gun 2 shown in FIG. 1 to turn it on, the push side wire feeder 4 and the pull side wire feeding A pair of wires W are fed to the thermal spray gun 2 by the feeder 9. The fed wire W passes through the inside of the gun main body 21, and then goes through the liner holding member 211 and the guide liner 23. Then, the wire W is sent to the feeding chip 22 while being guided by the guide liner 23, and while contacting the feeding chip 22, heads toward the arc point Ox along the central axis O1.

Electric power is supplied to the thermal spray gun 2 by the power supply unit 1. When the wire W comes into contact with the feeding chip 22, power is supplied from the feeding member 213 to the wire W via the feeding chip 22. Then, the pair of wires W sent out from the pair of power feeding chips 22 are short-circuited at the arc point Ox, so that an arc is generated between the tips of the pair of wires W and droplets are generated.

The first compressed gas (air) from the first gas supply means 3A is constantly sent to the thermal spray gun 2. The first compressed gas passes through the first gas supply path 25 (branch channel 251) and is constantly blown out from the first discharge port 252 into the internal space of the nozzle 24. The flow rate of the first compressed gas flowing through the first gas supply path 25 is, for example, about 800 to 1800 L / min. The flow velocity of the first compressed gas flowing into the internal space of the nozzle 24 is about 10 to 40 m / sec when flowing into the internal space.

The second compressed gas (argon gas) of the second gas supply means 3B is also intermittently sent to the thermal spray gun 2. The second compressed gas passes through the second gas supply path 26 (main flow path 261 and branch path 262) and is intermittently blown out from the second discharge port 263 into the internal space of the nozzle 24. The operation of intermittently supplying the second compressed gas to the thermal spray gun 2 is performed by opening and closing the second gas adjusting unit 36 (for example, a solenoid valve) of the second gas supply means 3B. The opening / closing cycle of the second gas adjusting unit 36 is not particularly limited, but for example, the opening / closing operation is performed about 10 to 30 times per second. In this case, the frequency of the second compressed gas supply is 10 to 30 Hz. The flow rate of the second compressed gas flowing through the second gas supply path 26 when the second compressed gas is supplied is, for example, about 20 to 120 L / min. The flow velocity of the second compressed gas flowing into the internal space of the nozzle 24 is about 40 to 300 m / sec when flowing into the internal space.

The first compressed gas that constantly flows in the nozzle 24 passes through the internal space of the nozzle 24, reaches the tip of the nozzle 24, and is constantly ejected to the outside from the gas ejection hole 242. The ejected gas is blown into the arc at the tip of the wire W, and the molten metal becomes droplets or fine particles to form a thermal spray coating on the surface of the object to be sprayed. At the same time, the second compressed gas that intermittently flows in the nozzle 24 passes through the internal space of the nozzle 24 and reaches the tip of the nozzle 24, and intermittently energizes the first compressed gas from the gas ejection hole 242. It is ejected.

Then, when the thermal spraying work is completed, the operator opens the start switch 7 of the thermal spraying gun 2 to turn it off. Then, the gas ejection from the gas ejection hole 242 is stopped, the supply and power supply of the pair of wires W are stopped, and the thermal spraying work is completed.

Next, the operation of this embodiment will be described.

In the present embodiment, a first discharge port 252 for blowing out the first compressed gas into the internal space of the nozzle 24 and a second discharge port 263 for blowing out the second compressed gas into the internal space of the nozzle 24 are provided. Has been done. The second discharge port 263 is located closer to the gas ejection hole 242 in the direction x than the first discharge port 252. The first compressed gas (air) is constantly supplied to the thermal spray gun 2 by the first gas supply means 3A, and the first compressed gas is constantly blown out from the first discharge port 252 into the internal space of the nozzle 24. .. Further, the second compressed gas (argon gas) is intermittently supplied to the thermal spray gun 2 by the second gas supply means 3B, and the second compressed gas is intermittently blown out from the second discharge port 263 into the internal space of the nozzle 24. Will be done. According to such a configuration, a gas in which a second compressed gas that is intermittently supplied in addition to the first compressed gas that is constantly supplied is ejected from the gas ejection hole 242, and the molten metal of the wire W is formed. It can be made finer to form a dense thermal spray coating.

The second compressed gas is intermittently blown out from the second discharge port 263. As a result, the molten metal is intermittently miniaturized. Unlike the present embodiment, when the molten metal is continuously miniaturized, the sprayed coating has no voids and becomes dense, but the oxidation rate increases. On the other hand, in the present embodiment, the miniaturization of the molten metal is appropriately controlled. As a result, a sprayed coating having a low oxidation rate, a high density and a high degree of adhesion is formed, and the quality of the sprayed coating can be improved.

The cross-sectional area of the second discharge port 263 is smaller than the cross-sectional area of the first discharge port 252. According to such a configuration, the second compressed gas having a high speed and a relatively small flow rate is blown out from the second discharge port 263 and directed toward the gas ejection hole 242. As a result, the molten metal is appropriately miniaturized.

In the present embodiment, the second discharge port 263 is provided for each of the pair of power feeding chips 22. Such a configuration is suitable for directing the second compressed gas to the gas ejection hole 242.

In the present embodiment, the flow rate, the flow velocity, and the supply time of the second compressed gas supplied to the internal space of the nozzle 24 can be adjusted by the second gas supply means 3B (second gas adjusting unit 36). According to such a configuration, the degree of miniaturization of the molten metal can be appropriately controlled.

Further, the second gas supply means 3B for supplying the second compressed gas is provided separately from the first gas supply means 3A for supplying the first compressed gas. According to such a configuration, the second compressed gas made of a gas different from the first compressed gas that is constantly supplied can be intermittently supplied under the conditions suitable for miniaturization.

In the present embodiment, the first compressed gas that is constantly supplied is air, and the second compressed gas that is intermittently supplied is argon gas. The supply of argon gas raises the temperature of the gas flow and promotes the miniaturization of the molten metal. By intermittently supplying this argon gas, it is possible to efficiently control the size of the molten particles while suppressing the cost increase.

FIG. 7 shows another example of a thermal spray gun according to the present invention. In FIG. 7, the same or similar elements as those in the above embodiment are designated by the same reference numerals as those in the above embodiment, and the description thereof will be omitted as appropriate.

In the thermal spray gun 2 of the present embodiment, the configuration of the nozzle 24 and the configuration of the second gas supply path 26 are different from those of the above embodiment. The nozzle 24 includes a first member 24A and a second member 24B. The first member 24A has an inner surface 241 and a gas ejection hole 242, and has an annular shape surrounding the tip portions of the pair of feeding chips 22. The second member 24B is externally fitted to the first member 24A and has a cylindrical shape.

In the present embodiment, the second gas supply path 26 is provided inside the nozzle 24. The second gas supply path 26 includes a main flow path 261, an annular groove 264, a branch path 262, and a second discharge port 263.

The main flow path 261 and the annular groove 264 are formed in the second member 24B. The second compressed gas is supplied to the main flow path 261 via the second gas pipe 34. The annular groove 264 is an annular shape formed in the inner peripheral portion of the second member 24B, and the main flow path 261 communicates with the annular groove 264. The branch path 262 is formed in the first member 24A. In the present embodiment, a pair of branch paths 262 are formed in the first member 24A. Each of the pair of branch paths 262 leads to the annular groove 264, and is provided on the opposite side of the axis CL of the nozzle 24. Each branch path 262 extends toward the gas ejection hole 242, and the downstream end of each branch path 262 is a second discharge port 263 open to the internal space of the nozzle 24.

The second discharge port 263 is an opening for blowing out the second compressed gas into the internal space of the nozzle 24. The second discharge port 263 is located closer to the gas ejection hole 242 than the first discharge port 252 in the direction x. Each second discharge port 263 faces the gas ejection hole 242.

As can be understood from FIGS. 6 and 7, in the present embodiment, the cross-sectional area of the second discharge port 263 is smaller than the cross-sectional area of the first discharge port 252. The ratio of the cross-sectional area of the second discharge port 263 to the cross-sectional area of the first discharge port 252 is, for example, about 0.1 to 0.5 times. Further, the ratio of the diameter (inner diameter) of the second discharge port 263 to the diameter of the wire W is, for example, about 0.5 to 1.5 times.

In this embodiment, under the same thermal spraying conditions as in the case of the above-described embodiment shown in FIGS. 4 to 6 and the like (the wire feeding rate, the supply mode of the first compressed gas and the second compressed gas, and the power supply mode are the same). Perform thermal spraying work. In the present embodiment, a first discharge port 252 for blowing out the first compressed gas into the internal space of the nozzle 24 and a second discharge port 263 for blowing out the second compressed gas into the internal space of the nozzle 24 are provided. ing. The second discharge port 263 is located closer to the gas ejection hole 242 in the direction x than the first discharge port 252. The first compressed gas (air) is constantly supplied to the thermal spray gun 2 by the first gas supply means 3A, and the first compressed gas is constantly blown out from the first discharge port 252 into the internal space of the nozzle 24. .. Further, the second compressed gas (argon gas) is intermittently supplied to the thermal spray gun 2 by the second gas supply means 3B, and the second compressed gas is intermittently blown out from the second discharge port 263 into the internal space of the nozzle 24. Will be done. According to such a configuration, a gas in which a second compressed gas that is intermittently supplied in addition to the first compressed gas that is constantly supplied is ejected from the gas ejection hole 242, and the molten metal of the wire W is formed. It can be made finer to form a dense thermal spray coating.

The second compressed gas is intermittently blown out from the second discharge port 263. As a result, the molten metal is intermittently miniaturized. Unlike the present embodiment, when the molten metal is continuously miniaturized, the sprayed coating has no voids and becomes dense, but the oxidation rate increases. On the other hand, in the present embodiment, the miniaturization of the molten metal is appropriately controlled. As a result, a sprayed coating having a low oxidation rate, a high density and a high degree of adhesion is formed, and the quality of the sprayed coating can be improved. In the configuration of the present embodiment shown in FIG. 7, other actions and effects similar to those of the above-described embodiment are exhibited.

Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to the above-described embodiments, and any changes within the scope of the matters described in each claim are the scope of the present invention. Is included in.

A1: Thermal spraying system, 2: Thermal spraying gun, 21: Gun body, 22: Feeding tip, 24: Nozzle, 242: Gas ejection hole, 252: First ejection port, 263: Second ejection port, 3A: First gas supply Means, 3B: second gas supply means, W: wire, x: direction (first direction)

Claims (5)

The gun body through which a pair of wires are inserted inside,
A nozzle provided at the tip of the gun body and having an internal space,
A pair of feeding chips, which are arranged in the internal space and have through holes for inserting the pair of wires, are provided.
The nozzle has a gas ejection hole at the tip portion that faces the first direction, which is the direction from the proximal end side to the distal end side.
A first discharge port for blowing out the first compressed gas toward the internal space, and a second compression toward the internal space, which is closer to the gas ejection hole in the first direction than the first discharge port. A thermal spray gun with a second outlet for blowing gas. The thermal spray gun according to claim 1, wherein the cross-sectional area of the second discharge port is smaller than the cross-sectional area of the first discharge port. The thermal spraying gun according to claim 2, wherein the second discharge port is provided for each of the pair of feeding chips. The thermal spray gun according to any one of claims 1 to 3, a first gas supply means for constantly supplying the first compressed gas to the thermal spray gun, and intermittently supplying the second compressed gas to the thermal spray gun. A thermal spraying system comprising a second gas supply means for supplying. The thermal spraying system according to claim 4, wherein the first compressed gas is air and the second compressed gas is argon gas.

Images