JP2000351090A - Laser thermal spraying nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser thermal spraying nozzle capable of jetting a stable gas without deviation. SOLUTION: This nozzle 1 is provided with a wire feeding port 61 at the central part through which a wire is fed to a molten droplet zone, plural inner gas jetting nozzles 62 which are provided around the wire feeding port 61 concentrically with it at equal interval in the circumferential direction, and an outer gas jetting nozzle 63 which is provided around these inner gas jetting nozzles 62 concentrically with these.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle for laser spraying.

[0002]

2. Description of the Related Art As a nozzle used in a laser spraying method, a gas is sprayed onto a molten droplet portion where a wire material as a thermal spraying material is melted by a laser beam to atomize the molten droplet portion and spray the surface to be sprayed. For example, a nozzle described in Japanese Patent Publication No. 5-468 is known.

[0003] As shown in FIG.
It has an inner nozzle 101 having a wire (wire) supply port 100 at the center, a middle nozzle 102 arranged outside the inner nozzle 101, and an outer nozzle 103 arranged outside the middle nozzle 102. Between the outer peripheral surface of the inner nozzle 101 and the inner peripheral surface of the middle nozzle portion, and the middle nozzle 102
A gap is provided between the outer peripheral surface of the outer nozzle 103 and the inner peripheral surface of the outer nozzle 103, and an annular inner gas outlet 104 and an outer gas outlet 105 are respectively formed.

[0004]

However, in such a conventional nozzle for laser spraying, the inner nozzle 1
01, the middle nozzle 102 and the outer nozzle 103 are combined to form an annular gap as an inner gas outlet 104 and an outer gas outlet 105, respectively. Therefore, the cylindricity, concentricity, etc. of these gas outlets 104, 105 are determined. It is difficult to assemble the nozzle while maintaining sufficient accuracy. Therefore, these gas ejection ports 104,
105 becomes eccentric and uneven, resulting in a problem that the gas blowing direction is not stable.

Further, in order to change the opening areas of the gas ejection ports 104, 105, the inner nozzle 101, the middle nozzle 102
In addition, it is necessary to change the outer nozzle 103, which makes it difficult to change conditions such as the gas flow rate. Therefore, there is a problem that it is difficult to change the particle size of the molten fine particles, and eventually the particle size of the powder that has been cooled and solidified on the surface to be sprayed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laser spray nozzle capable of performing stable and stable gas ejection. Still another object of the present invention is to provide a laser spray nozzle capable of easily changing the opening area and the like of a gas ejection port.

[0007]

In order to achieve the above object, a nozzle for laser spraying according to claim 1 is provided in a molten droplet portion where a wire as a sprayed material is melted by a laser beam.
A nozzle for laser spraying used in a laser spraying method for atomizing the molten droplet portion by spraying a gas and spraying the droplet onto a surface to be sprayed, and a wire rod supply at a central portion for supplying the wire rod to the molten droplet portion. A plurality of inner gas outlets provided around the wire supply port concentrically and at equal intervals in the circumferential direction around the wire supply port, and the inner gas It has an outlet and an outer gas outlet provided concentrically.

The nozzle for laser spraying according to claim 2 is
In claim 1, the outer gas ejection port is formed in an annular shape.

The nozzle for laser spraying according to claim 3 is
In claim 2, a nozzle tip comprising a nozzle tip body and a cylindrical outer tip is removably attached to a tip of the nozzle body, and the nozzle tip body has
The wire gas supply port and the inner gas ejection port are formed, and a gap is provided between the outer peripheral surface of the nozzle tip body and the inner peripheral surface of the outer tip to form the annular outer gas ejection port. It is characterized by that.

The nozzle for laser spraying according to claim 4 is
In the first aspect, the outer gas ejection port is formed of a plurality of outer gas ejection ports provided at equal intervals in a circumferential direction.

The nozzle for laser spraying according to claim 5 is:
5. The nozzle according to claim 4, wherein a nozzle tip having the wire supply port, the inner gas ejection port, and the outer gas ejection port is detachably attached to a tip portion of a nozzle body. is there.

According to the first aspect of the present invention, since the wire supply port and the inner gas ejection port around the wire supply port can be formed as an integral member, the eccentricity of the inner gas ejection port associated with assembly can be prevented. . Further, since the number of openings in the circumferential direction is reduced as compared with a conventional nozzle having an inner gas ejection port formed in an annular shape, gas consumption can be reduced and gas flow speed can be increased.

According to the second aspect of the present invention, since the outer gas outlet is formed in an annular shape, there is a possibility that the outer gas outlet may be slightly eccentric and uneven in thickness during assembly, but the influence on the molten fine particles is small.

According to the third aspect of the present invention, the opening area, arrangement, ejection angle, etc. of the inner gas outlet or the outer gas outlet can be easily changed by replacing the nozzle tip body, the outer tip, or both of them. Can be.

According to the fourth aspect of the present invention, the wire supply port, the inner gas outlet around the wire supply port, and the outer gas outlet around the wire supply port can be formed as an integral member.
Eccentricity of the inner gas outlet and the outer gas outlet associated with assembly can be prevented.

According to the fifth aspect of the present invention, by replacing only the nozzle tip, it is possible to easily change the opening area, arrangement, ejection angle and the like of the inner gas ejection port or the outer gas ejection port.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the nozzle for laser spraying according to the present invention will be described below with reference to the drawings. FIG. 4 is a schematic view showing a laser spraying apparatus according to the present embodiment. In FIG. 4, reference numeral 1 denotes a nozzle, and a wire (wire) 2, which is a thermal spray material, is supplied from above to a central portion of the nozzle 1 by a wire supply device (not shown). Project downward from the lower end of the cover. Further, the inner gas 3 and the outer gas 4 are supplied into the nozzle 1 and are ejected downward from the lower end of the nozzle 1.

On the other hand, a laser beam 5 as a heat source for thermal spraying is used.
Is transmitted through an optical fiber from a laser generator (not shown), enters the apparatus from the lateral direction (left in the figure), is condensed by a condenser lens 6, and then reaches a damper 7. The wire 2 is supplied to the central portion where the laser beam 5 is focused or the vicinity thereof. On the downstream side of the condenser lens 6 in the optical path of the laser beam 5, a protective glass 8 is provided, and further downstream, a lens shield gas 9 is supplied so as to be orthogonal to the optical path. The penetration of the thermal spray powder into the fin is suppressed. Further, before the damper 7 in the optical path of the laser beam 5, the damper shield gas 10 is supplied so as to be orthogonal to the optical path, so that penetration of the thermal spray powder into the damper 7 is suppressed.

Below the apparatus, a material to be sprayed 12 is fixed on an XY table 11 which can be moved in two axial directions, and in the lower part of the apparatus, near the material to be sprayed 12 from the lower end of the apparatus. Is provided.

Next, the nozzle 1 will be described with reference to FIGS. The nozzle 1 includes a nozzle body 21, a gas supply member 22 fitted outside the nozzle body 21, a nozzle tip body 23 provided at a tip end of the nozzle body 21, and a cylindrical shape provided outside the tip end. , And a nut member 25 for attaching the nozzle tip body 23 and the outer tip 24. The nozzle tip 26 is formed by the nozzle tip body 23 and the outer tip 24.

A wire passage 31 for supplying the wire 2 is formed at the center of the nozzle main body 21 along the axis. Outside the wire passage 31, the wire passage 31 is concentric with the wire passage 31 and is equally spaced circumferentially. A plurality of inner gas passages 32 are formed, and a plurality of outer gas passages 33 are formed further outside of the plurality of outer gas passages 33 concentrically with the inner gas passages and at equal intervals in the circumferential direction. Inner gas passage 32
The base end of the outer gas passage 33 is connected to the inner gas inlet 38 and the outer gas inlet 39 of the gas supply member 22, respectively.

The base end face of the nozzle tip body 23 is in contact with the tip end face of the nozzle body 21. A wire passage 41 for supplying the wire 2 is formed at the center along the axis. On the outside, a plurality of inner gas passages 42 are formed concentrically with the wire passage 41 and at equal intervals in the circumferential direction so as to approach the wire passage 41 toward the distal end side, and further outside these. A plurality of outer gas passages 43 approaching the wire passage 41 toward the distal end are formed concentrically with the wire passage 41 and at equal intervals in the circumferential direction.

The tip portion of the nozzle tip body 23 is reduced in diameter to form a reduced diameter portion 44, and an outlet 46 of the outer gas passage 43 is formed in a step surface 45. The base ends of the wire passage 41, the inner gas passage 42, and the outer gas passage 43 are connected to the wire passage 31, the inner gas passage 32, and the outer gas passage 33 of the nozzle body 21, respectively.

Also, at the base end of the outer tip 24,
A flange 51 is formed, and a tapered surface 53 is formed at the base end of the inner peripheral surface 52 so as to gradually widen toward the base end. The fitting portion 54 at the base end of the outer tip 24 is fitted to a fitting portion 47 formed on the step surface 45 of the nozzle tip body 23. A cylindrical gap 55 is provided between the inner peripheral surface 52 and the outer peripheral surface of the reduced-diameter portion 44 of the nozzle tip body 23, and an outlet 46 of the outer gas passage 43 is provided in a gap inside the tapered surface 53. Is located.

At the tip end surface of the nozzle tip body 23, there are a wire supply port (wire supply port) 61 which is an exit of the wire passage 41 in the center, and an exit of the inner gas passage 42,
A plurality of inner gas outlets 62 having a circular cross-sectional shape which are located concentrically and at equal intervals in the circumferential direction around the wire supply port 61, and a tip side opening of a cylindrical gap 55, An annular outer gas ejection port 63 provided concentrically with the inner gas ejection port 62 is formed around the inner gas ejection port 62.

An engaging portion 71 projecting inward is formed at the distal end of the nut member 25, and a female screw 72 is formed inside the proximal end. This nut member 25
The inner peripheral surface is fitted to the outer peripheral surfaces of the nozzle tip body 23 and the outer tip 24, and the engaging portion 71 is engaged with the flange portion 51 of the outer tip 24, and
Is screwed into a male screw 34 formed on the outer periphery of the distal end portion.
Thereby, the nozzle tip body 23 and the outer tip 2
4 is mounted on the tip of the nozzle body 21.

Next, a laser spraying method using the laser spraying apparatus configured as described above will be described. At the center or near the center of the laser beam 5 transmitted from the laser generator through an optical fiber and focused by the focusing lens 6, a wire 2, which is a thermal spray material, is passed from above the nozzle 1 to a wire supply passage of the nozzle body 21. It is supplied from a wire supply port 61 through 31.

The inner gas 3 is supplied to the inner gas inlet 38 of the nozzle 1, the inner gas passage 32, and the inner gas passage 42 through the plurality of inner gas outlets 6.
2, and the outer gas 4 is ejected from the annular outer gas outlet 63 through the outer gas inlet 39, the outer gas passage 33, and the outer gas passage 43.

In this manner, the wire 2 is melted by the laser beam 5, and the inner gas 3
Is sprayed to atomize the molten droplet portion, and the molten fine particles are sprayed on the surface to be sprayed of the material to be sprayed 12 by the gas flow of the inner gas 3 to form a sprayed film. The outer gas 4 is ejected so as to shield the outside of the molten fine particles, thereby suppressing scattering of the molten fine particles and suppressing oxidation of the molten fine particles. The thermal spray shield 13 also suppresses the scattering of the molten fine particles.

In the nozzle 1 for laser spraying as described above, the wire supply port 61 and the inner gas outlet 62 around the wire supply port 61 can be formed in the nozzle tip body 23, which is an integral member, so that it is assembled. As a result, the eccentricity of the inner gas ejection port 62 can be prevented, so that stable gas ejection without deviation can be performed, and stable thermal spraying can be performed. In addition, the number of openings in the circumferential direction can be reduced as compared with a conventional nozzle in which the inner gas ejection port is formed in an annular shape, so that the gas consumption can be reduced and the gas flow speed can be increased. it can.

A nozzle tip 26 comprising a nozzle tip body 23 and an outer tip 24 is removably attached to a tip end of the nozzle body 21 by a nut member 25, and a wire supply port 61 is attached to the nozzle tip body 23.
And an inner gas outlet 62 are formed, and a gap is provided between the outer peripheral surface of the nozzle tip body 23 and the inner peripheral surface of the outer tip to form an annular outer gas outlet 62. So, the nozzle tip body 23,
By exchanging the outer tip 24 or both alone, the opening area, arrangement, or ejection angle of the inner gas ejection port 62 or the outer gas ejection port 63 can be easily changed. After cooling and solidifying on the sprayed surface, the particle size of the powder that has become powder can be changed, and appropriate spraying can be performed.

Since the outer gas injection port 63 is formed in an annular shape, there is a possibility that the outer gas injection port 63 may be slightly eccentric or uneven in thickness during assembly. However, since the influence on the molten fine particles is small, stable spraying is not impaired. .

FIGS. 5 and 6 are views showing a nozzle tip according to another embodiment. Note that, in this embodiment, the configuration other than the nozzle tip is the same as that of the above-described embodiment, and a description thereof will be omitted. This nozzle tip 26
In A, the nozzle tip body and the outer tip are integrally formed. A wire passage 81 for supplying the wire 2 is formed at a central portion along the axis of the nozzle tip 26A, and a plurality of inner gas passages 82 that approach the wire passage 81 toward the distal end side are formed outside the wire passage 81.
Are formed concentrically with the wire passage 81 and at equal intervals in the circumferential direction, and further outside thereof, a plurality of outer gas passages 83 approaching the wire passage 81 toward the distal end side are formed. Are formed concentrically and at equal intervals in the circumferential direction.

The base ends of the wire passage 81, the inner gas passage 82, and the outer gas passage 83 are connected to the wire passage 31, the inner gas passage 32, and the outer gas passage 33 of the nozzle body 21, respectively.

Further, on the tip end surface of the nozzle tip 26A,
A wire supply port (wire supply port) 91 which is an exit of the wire passage 81 at the center, and an exit of the inner gas passage 82 which is concentric with the wire supply port 81 and equidistant in the circumferential direction. , A plurality of inner gas outlets 92 having a circular cross-sectional shape, and an outlet of the outer gas passage 83, which are located concentrically around the inner gas outlet 82 and at equal intervals in the circumferential direction. And a plurality of outer gas injection ports 93 having a circular cross section.

A step surface 84 is formed on the nozzle tip 26A, and the base end face of the nozzle tip 26A is brought into contact with the tip end face of the nozzle body 21. Mated to the surface,
The engaging portion 71 of the nut member 25 is engaged with the step portion 84, and the male screw 3 formed on the outer periphery of the distal end portion of the nozzle body 21 is formed.
When the female screw 72 of the nut member 25 is screwed into the nozzle 4, the nozzle tip 26 </ b> A is attached to the tip of the nozzle body 21.

In the nozzle of this embodiment, since a plurality of inner gas 92 and outer gas outlet 93 are provided at equal intervals in the circumferential direction, the wire supply port 91, the inner gas outlet 92, Since the outer gas ejection port 93 and the outer gas ejection port 93 can be formed in the nozzle tip 26A, which is an integral member, the eccentricity of the inner gas ejection port 92 and the outer gas ejection port 93 associated with the assembly can be prevented, and therefore, there is no deviation. Stable gas ejection can be performed, and stable thermal spraying can be performed.

Further, the nozzle tip 26A having the wire supply port 91, the inner gas outlet 92, and the outer gas outlet 93 is detachably attached to the tip of the nozzle body 21 by the nut member 25. By exchanging only the tip 26A, it is possible to easily change the opening area, the arrangement, the ejection angle, and the like of the inner gas ejection port 92 or the outer gas ejection port 93, so that appropriate thermal spraying can be performed. .

[0039]

Embodiments of the present invention will be described below. The laser spraying apparatus used in this embodiment is shown in FIG.
The wire (wire) as the thermal spray material is an industrial titanium wire (diameter: 0.8 mm, purity: 99.9%), and the base material (material to be sprayed) 12 is a rolled steel material for general structure SS400 (length 6).
0 mm x width 50 mm x thickness 15 mm). Substrate 1
In the pretreatment of No.2, alumina grit (# 36)
After blasting using, ultrasonic cleaning was performed using acetone. As the inner gas 3 and the outer gas 4, nitrogen gas (99.8%) was used. As a laser 5 as a heat source for thermal spraying, a YAG laser (maximum output (continuous emission) 2 kW, MW2000 manufactured by Sumitomo Heavy Industries, Ltd.) was used after being transmitted by an optical fiber.

As the nozzle 1, those having the nozzle tip 26 shown in FIGS. 1 to 3 and those having the nozzle tip 26A shown in FIGS. 5 and 6 were also used. Further, as a comparative example, thermal spraying was performed using the conventional nozzle 1B shown in FIG.

The nozzle 1 having the nozzle tip 26 is shown in FIGS.
Has a diameter of 0.8 mm,
Has a diameter of 0.5 mmφ, a number of eight, a pitch circle diameter of 2.1 mm, a gradient of 9 ° with respect to the axis of the nozzle tip body 23, and the inner gas 3 ejected from the inner gas ejection port 62. At a position 5 mm from the tip of the nozzle (tip of the nozzle tip body 23) on the axis of, the diameter of the outlet 46 of the outer gas passage 43 is 1.0 mmφ, and the number is 12
Pcs, pitch circle diameter 10.5mm, nozzle tip body 2
The gradient with respect to the axis 3 is 5 °, and the inner diameter of the annular outer gas ejection port 63 is 7 mmφ and the outer diameter is 8 mmφ, and is open straight downward. Nozzle P0
5 is a pitch circle diameter of the inner gas ejection port 62 of 2.5
mm and the gradient with respect to the axis of the nozzle tip body 23 is 12 °, so that the inner gas 3 ejected from the inner gas ejection port 62 converges to one point at a position 4.7 mm from the nozzle tip on the axis of the nozzle tip body 23. Are the same as those of the nozzle P02. Nozzle P
07 is 0.7 mm in diameter of the inner gas ejection port 62.
φ, the pitch circle diameter is 2.5 mm, the gradient with respect to the axis of the nozzle tip body 23 is 12 °, and the inner gas 3 ejected from the inner gas ejection port 62 is 4.7 mm from the nozzle tip on the axis of the nozzle tip body 23. Other than converging to one point at the position of nozzle P0
Same as 2.

On the other hand, in the nozzle 1 having the nozzle tip 26A, in FIGS. 5 and 6, the nozzle P11 has a wire supply port 91 having a diameter of 0.8 mmφ and an inner gas ejection port 92 having a diameter of 0.5 mmφ. The number is 8 mm, the pitch circle diameter is 2.1 mm, the gradient with respect to the axis of the nozzle tip 26A is 9 °, the outer gas outlet 93 has a diameter of 0.5 mmφ, the number is 8, and the pitch circle diameter is 3. 7m
m, the gradient with respect to the axis of the nozzle tip 26A is 18 °
Thus, both the inner gas 3 ejected from the inner gas ejection port 92 and the outer gas 4 ejected from the outer gas ejection port 93 are located at a position 5 mm from the nozzle tip (nozzle tip 26A tip) on the axis of the nozzle tip 26A. It converges to one point. Nozzle P12
, The inner gas jet 92 is the outer gas jet 9
It is the same as the nozzle P11 except that the number of 3 is 12.

In the conventional nozzle 1B, in FIG. 12, the diameter of the wire supply port 100 is 1.0 mmφ, the inner diameter of the annular inner gas jet 104 is 2 mmφ, the outer diameter is 3 mmφ, and 12 ° gradient
And the inner diameter of the annular outer gas ejection port 105 is 1
It has a diameter of 0 mmφ and an outer diameter of 11 mmφ and opens straight downward.

The titanium wire 2 as a thermal spray material was supplied by a wire supply device to the center where the laser beam 5 was condensed by the condenser lens 6. The molten titanium reacts with nitrogen gas ejected from a nozzle to a molten portion, and forms titanium nitride (hereinafter “TiN”).
At the same time as the above), and at the same time, were atomized by the gas pressure and accumulated on the substrate 12. Except for some nozzles, the gas ejected from the outer gas ejection port was used to shut off the atmosphere to prevent oxidation of TiN particles.

Thermal spraying conditions were as follows: laser output 1500 W, wire supply speed 30 mm / s, inner gas flow rate 72 to
200 l / min, outer gas flow rate 0-300 l /
In the nozzle of the present invention, the gas that basically contributes to the finer spray particles used was the maximum flow rate at which the original pressure was 5 atm. Spray distance is 200m
m, the laser irradiation position on the titanium wire was 3 mm from the tip of the nozzle. Here, the laser output refers to the value of the power meter of the laser oscillator, and is irradiated onto the wire 2 after an energy loss of about 20 to 30% is actually caused by the optical fiber transmission or the condenser lens 6 and the protection lens 8. Therefore, it differs from real energy. The thermal spray shield 13 has a diameter of 65
mmφ and 150 mmφ were used.

FIG. 7 is an external view of the thermal spray coating. Compared with the conventional nozzle 1B, the spray coating formed by the nozzle P02, in which a plurality (eight) of inner gas jet ports 62 are arranged concentrically with the wire supply port 61 and at equal intervals in the circumferential direction, Due to the small amount of gas contributing to the fineness, the sprayed coating has some roughness, while the outer gas jet port 93 is also sprayed by the nozzle P12 arranged toward the molten droplet portion so as to contribute to the finer sprayed particles. The coating was almost the same in appearance as the conventional nozzle 1B.

In order to examine this in further detail, O (oxygen) and N (nitrogen) analysis of the thermal sprayed coating and powder recovery of the thermal sprayed particles were performed, and the particle size distribution was examined. The results are shown in Table 1 and FIGS.

[0048]

[Table 1]

According to Table 1, the diameter of the thermal spray shield 13 is 65.
It can be seen that there is no significant difference between the N content and the O content for mmφ. Accordingly, there is no significant difference in the nitriding ratio, and it is presumed that a TiN sprayed coating equivalent in composition is formed. However, when the thermal spraying shield 13 has a diameter of 150 mm, there is a large difference in the amount of O. In particular, the amount of O in the nozzle P12 is large, and this appears as a difference in the amount of N.
This is considered to be the difference in the amount of N ₂ used during thermal spraying.
Oxidized when the amount of ₂ is less high than necessary spray shield 13 by entrainment of air indicates to proceed. However, even if the gas flow rate is large, if the content of O is 5% or more, it is considered that the characteristics of TiN are remarkably deteriorated. Therefore, it is necessary to use an appropriate thermal spray shield even if thermal spray efficiency is ignored. You can see that.

Next, the following points can be found from the particle size distribution of the sprayed particles. FIG. 8 shows the nozzles P02, P11, and P12 and, in this order, changes in the particle size distribution when the gas pressure and the flow rate are constant and only the flow rate is increased. From the figure, it can be seen that the particle size distribution tends to become finer as the gas flow rate increases. That is, it is suggested that the nozzle P12 shows a particle size distribution equivalent to that of the conventional nozzle 1B, and that the properties of the thermal spray coating are close.

FIG. 9 shows that when the gas flow rate of the nozzle P07 is reduced to 78 l / min and when compared with the nozzle P05, the flow rate of the nozzle P07 is constant but the gas pressure and the flow rate are lower than those of the nozzle P05. It is considered the case. Since the spray particles are remarkably coarsened when the flow velocity is reduced to about half, it is guessed that the flow velocity and the gas pressure are also significant factors for making the spray particles finer.

From these results, it is considered that the sprayed coating is formed in the nozzle P12 equal to or larger than that of the conventional nozzle 1B.
Since the outer gas 4 is used for making the thermal spray particles finer, the effect of the outer gas 4 on the shielding and converging effects of the thermal spray particles, which is the original role of the outer gas 4, is shown.

In order to investigate this, the thermal spray shield 13
Was sprayed on a stainless steel plate for 20 seconds under each condition. The result is shown in FIG. Outer gas 4
The effect of nozzle P02 / inner gas flow rate 78l / m
It can be understood by comparing the in / outer gas flow rate 200 l / min with the nozzle P11 / inner gas flow rate 78 l / min and the outer gas flow rate 0 l / min. That is, by not flowing the outer gas 4, the nozzle P1
In Fig. 1, it can be seen that coarse particles are scattered far from the center of the spray axis.

On the other hand, the nozzle P12 that contributes to the outer gas 4 to make the spray particles finer has the advantage that the outer gas 4 has no effect of shielding and converging the spray particles by the outer gas 4.
The thermal spray particles are deposited at the center of the thermal spray axis, and the scattering particles are small. Further, it is presumed that the degree of oxidation of the adhered particles was low, and that the particles had an effect of shielding. The total gas flow rate is 2.6 times (500
1 / min), which is not much different from the result of a certain conventional nozzle 1B. This is presumably because the outer gas 4 also contributes to the miniaturization of the thermal spray particles, thereby increasing the effect of accelerating the thermal spray particles on the thermal spray axis, which is more effective than suppressing the outer gas 4 from scattering from the outside. This is inferred from the fact that the amount of dry ice caused by smashing the powder during powder recovery was extremely fast in P12. With this effect,
It is also expected that the spraying direction is hardly affected by the sowing habit of the wire, and is considered to be superior to the conventional nozzle 1B.

FIG. 1 shows a case where a thermal spray shield is attached.
As shown in FIG. 1, it is considered that even if there is a difference, the difference becomes smaller due to the shielding and convergence effects of the thermal spray shield 13. Further, in the nozzle P12, there is no need to distinguish between the outer 4 and the inner gas 3, and there is no problem even if the gas adjustment is the same. Therefore, it is possible to make the structure of the nozzle simpler, which suggests that a more economical effect can be expected.

[0056]

As described above, according to the laser spray nozzle of the first aspect, the wire supply port at the center for supplying the wire to the molten droplet portion and the periphery of the wire supply port are provided. A plurality of inner gas jets provided concentrically with the wire supply port and at equal intervals in the circumferential direction, and outer gas jets provided around the inner gas jets and concentrically with the inner gas jets. Since the structure having the outlet is provided, the wire supply port and the inner gas ejection port around the wire supply port can be formed as an integral member, so that eccentricity of the inner gas ejection port due to assembly can be prevented.
Therefore, it is possible to perform stable gas ejection without bias, and to perform stable thermal spraying. In addition, the number of openings in the circumferential direction can be reduced as compared with a conventional nozzle in which the inner gas ejection port is formed in an annular shape, so that gas consumption can be reduced and gas flow speed can be increased. it can.

According to the second aspect of the present invention, since the outer gas injection port is formed in an annular shape in the first aspect, there is a possibility that the outer gas injection port may be slightly eccentric or uneven at the time of assembly. Since the influence is small, stable thermal spraying can be maintained.

According to the third aspect of the present invention, in the second aspect, the nozzle tip comprising the nozzle tip body and the cylindrical outer tip is detachably attached to the tip of the nozzle body. The nozzle tip body has a wire supply port and an inner gas outlet formed therein, and a gap is provided between the outer peripheral surface of the nozzle tip body and the inner peripheral surface of the outer tip to form an annular outer gas. Since it is an ejection port, the opening area, arrangement or ejection angle of the inner gas ejection port or the outer gas ejection port can be easily changed by replacing the nozzle tip body, the outer tip or both alone,
Therefore, the particle size of the molten fine particles, and thus the particle size of the powder after cooling and solidifying on the surface to be sprayed, can be changed, and appropriate spraying can be performed.

According to the nozzle for laser spraying according to the fourth aspect, in the first aspect, the outer gas ejection port comprises a plurality of outer gas ejection ports provided at equal intervals in a circumferential direction. Since the mouth, the inner gas outlet around the mouth, and the outer gas outlet around the mouth can be formed as an integral member, the eccentricity of the inner gas outlet and the outer gas outlet associated with the assembly can be prevented. Therefore, stable and stable gas ejection can be performed, and stable thermal spraying can be performed.

According to the fifth aspect of the present invention, the nozzle tip having the wire supply port, the inner gas outlet, and the outer gas outlet is provided at the tip of the nozzle body. Since it is removably attached, it is possible to easily change the opening area, arrangement, ejection angle, etc. of the inner gas outlet or outer gas outlet by replacing only the nozzle tip, so that appropriate spraying can be performed. It can be carried out.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a nozzle for laser spraying of the present invention.

FIG. 2 is a sectional view showing a nozzle tip body according to an embodiment of the nozzle for laser spraying of the present invention.

FIG. 3 is a view as seen from a tip arrow of FIG. 2;

FIG. 4 is a schematic view showing a laser spraying apparatus according to one embodiment of the nozzle for laser spraying of the present invention.

FIG. 5 is a cross-sectional view showing a nozzle tip according to another embodiment of the nozzle for laser spraying of the present invention.

FIG. 6 is a view as seen from a tip arrow of FIG. 5;

FIG. 7 is an external view of a thermal spray coating.

FIG. 8 is a diagram showing a particle size distribution of spray particles.

FIG. 9 is a diagram showing a particle size distribution of spray particles.

FIG. 10 is a view showing a scattered state of spray particles when a spray shield is not attached.

FIG. 11 is a view showing a scattered state of spray particles when a spray shield is attached.

FIG. 12 is a sectional view showing a conventional laser spray nozzle.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser spray nozzle 2 wire (wire) 3 inner gas 4 outer gas 5 laser beam 21 nozzle body 23 nozzle tip body 24 outer tip 26, 26A nozzle tip 61, 91 wire supply port (wire supply port) 62, 92 inner gas Spout 63,93 Outer gas spout

 ──────────────────────────────────────────────────の Continued on the front page (71) Applicant 591214941 Shinwa Kogyo Co., Ltd. 2798-71, Minamiyoshida-cho, Matsuyama-shi, Ehime (72) Inventor Hiroshi Tomochika 487-2, Kume Kubota-cho, Matsuyama-shi, Ehime Pref. (72) Inventor Yuji Tadokoro 2-5-248 Higashimura-Minami, Imabari City, Ehime Prefecture Inside the Textile Testing Laboratory, Ehime Prefecture (72) Inventor Takao Araki 5-73-23, Soritani, Matsuyama City, Ehime Prefecture (72) Inventor Minoru Nishida Ehime 2652 Hirai-cho, Matsuyama-shi, Japan (72) Masahiro Kurase 2798-71 Minamiyoshida-cho, Matsuyama-shi, Ehime Shinwa Kogyo Co., Ltd. (72) Munehide Katsumura 2217-14, Hayashi-cho, Takamatsu-shi, Kagawa Shikoku Industrial Technology Research In-house F term (reference) 4E068 BB02 CH02 CH08 CJ01 4K031 CB46 DA07 EA01 EA08 EA10 EA12

Claims (5)

[Claims] 1. A laser used in a laser spraying method in which a gas is sprayed onto a molten droplet portion where a wire material as a thermal spraying material is melted by a laser beam to make the molten droplet portion fine and sprayed on a surface to be sprayed. A nozzle for thermal spraying, wherein a wire supply port at a center for supplying the wire to the molten droplet portion, and provided around the wire supply port concentrically with the wire supply port and at equal intervals in a circumferential direction. A nozzle for laser spraying, comprising: a plurality of inner gas outlets; and an outer gas outlet provided concentrically with the inner gas outlets around the inner gas outlets. 2. The laser spray nozzle according to claim 1, wherein the outer gas ejection port is formed in an annular shape. 3. A nozzle tip comprising a nozzle tip body and a cylindrical outer tip is detachably attached to a tip portion of the nozzle body, and the wire supply port and the inner gas ejection port are provided on the nozzle tip body. And a gap is provided between an outer peripheral surface of the nozzle tip main body and an inner peripheral surface of the outer tip to form the annular outer gas ejection port. Item 3. A nozzle for laser spraying according to item 2. 4. The laser spray nozzle according to claim 1, wherein the outer gas jet comprises a plurality of outer gas jets provided at equal intervals in a circumferential direction. 5. A nozzle tip having the wire supply port, the inner gas outlet, and the outer gas outlet is detachably attached to a tip end of a nozzle body. 5. The nozzle for laser spraying according to 4.