阅读说明：本技术 金属造形用保护气体喷嘴及激光金属造形装置 (Protective gas nozzle for metal forming and laser metal forming device ) 是由 中野善和 加藤木英隆 泽井章能 于 2019-04-16 设计创作，主要内容包括：金属造形用保护气体喷嘴(70)具有：线供给线(72),其是相对于母材面以倾斜角θ的角度供给线(2)的路径；第1气体喷出孔(75),其以小于或等于倾斜角θ的角度喷出保护气体；以及第2气体喷出孔(76),其从与第1气体喷出孔(75)的喷出方向不同的方向喷出保护气体。具有线供给方向(81)、第1气体喷出孔(75)的中心轴方向(82)及第2气体喷出孔(76)的中心轴方向(83)相交叉的交叉点(P),第1气体喷出孔(75)从在从相对于母材面的垂直方向观察的情况下的相对于线供给方向(81)的角度的绝对值小于90度的角度的方向朝向交叉点(P)喷出,第2气体喷出孔(76)从在从相对于母材面的垂直方向观察的情况下的相对于线供给方向(81)的角度的绝对值大于90度的角度的方向朝向交叉点(P)喷出。(A shielding gas nozzle (70) for metal forming comprises: a wire supply line (72) which is a path for supplying a wire (2) at an angle of an inclination angle theta with respect to the parent surface; a 1 st gas ejection hole (75) that ejects a shielding gas at an angle less than or equal to the inclination angle theta; and a 2 nd gas ejection hole (76) that ejects the shielding gas from a direction different from the ejection direction of the 1 st gas ejection hole (75). The jet nozzle has a cross point (P) where a line supply direction (81), a central axis direction (82) of a 1 st gas jet hole (75), and a central axis direction (83) of a 2 nd gas jet hole (76) intersect, wherein the 1 st gas jet hole (75) jets toward the cross point (P) from a direction at which an absolute value of an angle with respect to the line supply direction (81) is smaller than an angle of 90 degrees when viewed from a direction perpendicular to the surface of the master, and the 2 nd gas jet hole (76) jets toward the cross point (P) from a direction at which an absolute value of an angle with respect to the line supply direction (81) is larger than an angle of 90 degrees when viewed from a direction perpendicular to the surface of the master.)

1. A shielding gas nozzle for metal forming, comprising:

a wire supply line which is a path for supplying a wire at an angle of an inclination angle theta with respect to the surface of the mother material;

a 1 st gas ejection hole for ejecting a shielding gas for preventing oxidation of the weld bead at an angle smaller than or equal to the inclination angle θ with respect to the surface of the base material; and

a 2 nd gas ejection hole that ejects the shielding gas from a direction different from an ejection direction of the 1 st gas ejection hole,

a cross point where a line supply direction, which is a direction in which the line is supplied, intersects with a central axis direction of the 1 st gas ejection hole and a central axis direction of the 2 nd gas ejection hole at a position lower than the 1 st gas ejection hole and the 2 nd gas ejection hole,

the 1 st gas ejection hole ejects the shielding gas toward the intersection from a direction at an angle whose absolute value of an angle with respect to the line feeding direction is less than 90 degrees when viewed from a perpendicular direction with respect to the mother material surface,

the 2 nd gas ejection hole ejects the shielding gas toward the intersection from a direction at an angle having an absolute value of an angle greater than 90 degrees with respect to the line feeding direction when viewed from a perpendicular direction with respect to the mother material surface.

2. The shielding gas nozzle for metal forming according to claim 1,

and a 3 rd gas ejection hole for ejecting the shielding gas from a position higher than the 1 st gas ejection hole and the 2 nd gas ejection hole so as to pass through the space above the intersection.

3. The shielding gas nozzle for metal forming according to claim 2,

further comprising:

a gas inlet port for introducing the shielding gas discharged from the 3 rd gas discharge hole; and

and a gas direction changing line which is a path for supplying the shielding gas to the 2 nd gas ejection hole by changing the direction of the shielding gas introduced from the gas inlet.

4. The shielding gas nozzle for metal forming according to claim 1 or 2,

comprising:

a gas flow-splitting unit that splits the shielding gas and discharges the shielding gas from a plurality of directions to the intersection; and

a 1 st gas supply line which is a path for supplying the shielding gas to the gas flow splitting section,

the gas flow distribution portion includes:

the 1 st gas ejection hole and the 2 nd gas ejection hole; and

and a divided gas supply line which is a path for dividing and supplying the shielding gas to the 1 st gas ejection hole and the 2 nd gas ejection hole.

5. The shielding gas nozzle for metal forming according to claim 4,

the gas flow dividing portion is in the form of a ring centered on the intersection when viewed in a direction perpendicular to the surface of the base material.

6. The shielding gas nozzle for metal forming according to any one of claims 1 to 5,

the 1 st and 2 nd gas spouting holes have a shape in which ends thereof are expanded toward outlets of the 1 st and 2 nd gas spouting holes.

7. A laser metal forming apparatus having the shielding gas nozzle for metal forming of any one of claims 1 to 6, the weld beads being laminated by heating and melting the wire by a laser,

the laser metal shaping device is characterized in that,

the position of the metal forming shield gas nozzle is controlled so that the position of the intersection overlaps with a position of a processing region where the weld bead is newly laminated by heating and melting the wire, and the laser beam is irradiated toward the intersection.

8. A laser metal forming apparatus having the shielding gas nozzle for metal forming of claim 2 or 3, wherein the weld bead is laminated by heating and melting the wire by a laser,

the laser metal shaping device is characterized in that,

the flow rate of the shielding gas is controlled so that the shielding gas discharged from the 3 rd gas discharge hole is in a laminar flow.

Technical Field

The present invention relates to a shielding gas nozzle for metal forming used for laser metal forming and a laser metal forming apparatus.

Background

There is a laser metal forming apparatus that performs laser metal forming using a linear forming material (hereinafter, simply referred to as "line") by a technique of melting a metal forming material using a laser having a high energy density as a heat source to form a weld bead composed of the melted forming material in a processing region. The machining region is a region where new weld beads are laminated by heating and melting a wire, and the machining region is formed on the base metal surface or the already laminated weld beads. When a weld bead is formed in a machining region by heating and melting a modeling material in an atmospheric atmosphere, the weld bead and a base material are oxidized by heat during heating and melting and oxygen contained in the atmosphere, and therefore a protective gas for preventing oxidation is supplied to the machining region and the vicinity thereof. As the shielding gas, for example, argon (Ar) and nitrogen (N) are usually used₂) By ejecting such an inert gas from the gas nozzle, the weld bead and the base material are cooled, and the atmosphere in the processing region and the vicinity thereof is shielded, thereby performing metal forming. This can prevent the weld bead and the base material from being oxidized. Patent document 1 discloses the same technique.

Patent document 1: japanese patent laid-open publication No. 2010-172941

Disclosure of Invention

When the shield gas supply shaft, which is the axial direction in which the shield gas is supplied, and the wire supply shaft, which is the axial direction in which the wire is supplied, are not coaxial, the wire blocks the shield gas in a machining region (hereinafter referred to as "back surface region") that is a position on the back surface of the wire when viewed from the shield gas supply direction, and the supply of the shield gas is hindered, which makes it difficult to prevent oxidation.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a shield gas nozzle for metal forming, which can prevent oxidation of a weld bead or a base material when laser metal forming is performed using a wire.

In order to solve the above problems and achieve the object, a shield gas nozzle for metal forming according to the present invention includes: a wire supply line which is a path for supplying a wire at an angle of an inclination angle theta with respect to the surface of the mother material; a 1 st gas ejection hole for ejecting a shielding gas for preventing oxidation of the weld bead at an angle of less than or equal to an inclination angle theta with respect to the surface of the base material; and a 2 nd gas ejection hole that ejects the shielding gas from a direction different from the ejection direction of the 1 st gas ejection hole. The metal forming shield gas nozzle has a cross point where a line supply direction, which is a direction in which a line is supplied, intersects with a central axis direction of the 1 st gas ejection hole and a central axis direction of the 2 nd gas ejection hole at a position lower than the 1 st gas ejection hole and the 2 nd gas ejection hole. Characterized in that the 1 st gas ejection hole ejects the shielding gas toward the intersection from a direction at an angle whose absolute value of the angle with respect to the line feeding direction is smaller than 90 degrees when viewed from the perpendicular direction with respect to the surface of the mother substrate, and the 2 nd gas ejection hole ejects the shielding gas toward the intersection from a direction at an angle whose absolute value of the angle with respect to the line feeding direction is larger than 90 degrees when viewed from the perpendicular direction with respect to the surface of the mother substrate.

ADVANTAGEOUS EFFECTS OF INVENTION

The shield gas nozzle for metal forming according to the present invention has an effect that it can ensure an atmospheric shielding property when laser metal forming is performed using a wire, and thus can prevent oxidation of a weld bead and a base metal.

Drawings

Fig. 1 is a schematic diagram showing a configuration of a laser metal shaping apparatus according to embodiment 1.

Fig. 2 is a schematic view of a shield gas nozzle for metal forming according to embodiment 1.

Fig. 3 is a schematic diagram illustrating a positional relationship between a processing region and an intersection according to embodiment 1.

Fig. 4 is a schematic diagram illustrating a positional relationship of gas ejection holes of the metal forming shield gas nozzle according to embodiment 1.

Fig. 5 is a schematic diagram showing a configuration in which the metal forming shield gas nozzle according to embodiment 1 has a 1 st gas ejection hole, a 2 nd gas ejection hole, and a 4 th gas ejection hole.

Fig. 6 is a hardware configuration diagram of a control device included in the laser metal forming apparatus according to embodiment 1.

Fig. 7 is a schematic view of a shield gas nozzle for metal forming according to embodiment 2.

Fig. 8 is a schematic view of a shield gas nozzle for metal forming according to embodiment 3.

Detailed Description

The metal forming shield gas nozzle and the laser metal forming apparatus according to the embodiment of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the embodiments.

Embodiment 1.

Fig. 1 is a diagram schematically showing the configuration of a laser metal modeling apparatus 100 according to embodiment 1 of the present invention. The laser metal shaping apparatus 100 heats and melts the wire 2 by the laser 1 to laminate the weld bead 3 in the processing region a on the base material surface. The base material 4 is placed on a table 5. The laser metal forming apparatus 100 includes a laser oscillator 10, a control device 20, a machining head 30, a wire supply device 40, a shielding gas supply device 50, a drive device 60, and a table 5. The machining head 30 includes a protective gas nozzle 70 for metal formation and a laser head 6 in a machining head body 31. The wire feeder 40 feeds the wire 2 to the metal forming shield gas nozzle 70. The shielding gas supply device 50 supplies a shielding gas to the shielding gas nozzle 70 for metal forming. The metal forming shield gas nozzle 70 supplies the wire 2 supplied from the wire supply device 40 to the processing area a, and discharges the shield gas to the processing area a. The laser oscillator 10 outputs the laser light 1 to the laser head 6 via the optical transmission path 7. The laser head 6 irradiates the laser beam 1 output through the optical transmission path 7 toward the processing region a. The driving device 60 includes a Z-axis driving device 63 for moving the machining head 30 in a Z-axis direction which is a vertical direction, an X-axis driving device 61 for moving the machining head 30 in an X-axis direction perpendicular to the Z-axis direction, and a Y-axis driving device 62 for moving the machining head 30 in a Y-axis direction perpendicular to the Z-axis direction and the X-axis direction, and moves the machining head 30 to a predetermined position. The control device 20 controls the laser oscillator 10, the wire supply device 40, the shield gas supply device 50, and the drive device 60 so that the weld beads 3 are layered in a desired machining region a.

Fig. 2 is a schematic view of a shielding gas nozzle 70 for metal forming in embodiment 1 of the present invention. Fig. 2(a) is a view seen from a vertical direction (Z-axis direction in fig. 1) with respect to the surface of the mother substrate, and fig. 2(b) is a view seen from a horizontal direction (X-axis direction in fig. 1) with respect to the surface of the mother substrate. The nozzle 71 includes a wire supply line 72, which is a path for supplying the wire 2 to the machining region a at an inclination angle θ with respect to the surface of the base material on which the weld bead 3 is formed, and a 1 st gas supply line 74, which is a path for supplying the shielding gas to a gas branching portion 73 for branching the shielding gas and discharging the shielding gas to the machining region a from a plurality of directions. The tip of the nozzle 71 is connected to an annular gas flow splitting portion 73 having a 1 st gas ejection hole 75 and a 2 nd gas ejection hole 76 which eject the shielding gas to the processing region a. The gas flow splitting portion 73 has a split gas supply line 77 as a path for splitting and supplying the shielding gas to the 1 st gas ejection hole 75 and the 2 nd gas ejection hole 76, and the split gas supply line 77 is connected to the 1 st gas supply line 74 in the nozzle 71 via a split point 78. In fig. 2, the 1 st gas supply line 74 has 2 paths, but if the 1 st gas ejection hole 75 is present in the extension of the 1 st gas supply line 74 on the outlet side, the shielding gas supplied from the 1 st gas supply line 74 flows directly through the 1 st gas ejection hole 75, and a flow difference from the shielding gas ejected from the 2 nd gas ejection hole 76 is likely to occur, so that only the extension of the 1 st gas supply line 74 and the extension of the 1 st gas ejection hole 75 do not overlap, and a plurality of them may not be necessary.

In embodiment 1 of the present invention, the wire supply line 72, the 1 st gas ejection hole 75, and the 2 nd gas ejection hole 76 are formed so as to have a cross point P where a wire supply direction 81 which is a direction of the supply line 2, a central axis direction 82 of the 1 st gas ejection hole 75, and a central axis direction 83 of the 2 nd gas ejection hole 76 intersect at a position lower than the 1 st gas ejection hole 75 and the 2 nd gas ejection hole 76. The central axis direction 82 of the 1 st gas ejection hole 75 and the central axis direction 83 of the 2 nd gas ejection hole 76 are central axis directions of the ejection directions of the shielding gas ejected from the respective gas ejection holes. Further, the laser head 6 is disposed so that the irradiation direction of the laser beam 1 also faces the intersection P. Fig. 3 is a schematic diagram illustrating a positional relationship between the processing area a and the intersection P. Fig. 3(a) shows a positional relationship between the machining region a and the intersection P when viewed from a vertical direction (Z-axis direction in fig. 1) with respect to the surface of the mother substrate, and fig. 3(b) shows a positional relationship between the machining region a and the intersection P when viewed from a horizontal direction (X-axis direction in fig. 1) with respect to the surface of the mother substrate. The position of the cross point P is preferably formed at a position where the pressures of the shielding gas blown out from both the central axis direction of the 1 st gas ejection hole 75 and the central axis direction of the 2 nd gas ejection hole 76 become uniform at the cross point P, but the position is not limited thereto. In embodiment 1 of the present invention, the wire supply line 72, the 1 st gas ejection hole 75, and the 2 nd gas ejection hole 76 are formed so that the vicinity of the center of the annular gas flow splitting part 73 becomes the intersection point P when viewed in the vertical direction with respect to the surface of the base material. That is, the gas flow splitting portion 73 is in a ring shape with the intersection point P as the center when viewed from the perpendicular direction with respect to the surface of the base material. When laser metal forming is performed, the position of the shielding gas nozzle 70 for metal forming is controlled so that the position of the intersection point P overlaps the machining area a, and the laser 1 is irradiated toward the intersection point P, whereby the weld beads 3 are layered by supplying the wire 2 to the desired machining area a, and the shielding gas is supplied to the layered weld beads 3 from a plurality of directions. In the following description, it is assumed that the position of the metal forming shield gas nozzle 70 is controlled and the position of the intersection P overlaps the machining area a, and therefore, the description may be made on the assumption that the shield gas is ejected toward the intersection from the 1 st gas ejection hole and the 2 nd gas ejection hole so as to be ejected toward the machining area a.

At least the outlet of the 1 st gas ejection hole 75 and the 2 nd gas ejection hole 76 is formed at a position closer to the base material surface than the position of the outlet of the wire supply line 72, and is formed to eject the shielding gas to the intersection at an angle smaller than or equal to the inclination angle θ with respect to the base material surface. The shape of the 1 st gas ejection hole 75 and the 2 nd gas ejection hole 76 is preferably a shape that expands toward the outlet of the gas ejection holes so that the weld bead 3 formed in the machining region a and its vicinity are covered with the shielding gas. In embodiment 1, the 1 st gas ejection hole 75 is formed directly below the wire supply line 72 and the 2 nd gas ejection hole 76 is formed on the 180-degree opposite side of the 1 st gas ejection hole 75 with the machining area a therebetween when viewed from the vertical direction with respect to the surface of the base material, but this is an example and is not limited to this positional relationship. The 1 st gas ejection hole 75 may be disposed in the gas flow splitting unit 73 so as to eject the shielding gas toward the intersection P from a direction at an angle whose absolute value is smaller than 90 degrees with respect to the line supply direction 81 when viewed from the perpendicular direction with respect to the surface of the mother substrate, and the 2 nd gas ejection hole 76 may be disposed in the gas flow splitting unit 73 so as to eject the shielding gas toward the intersection P from a direction at an angle whose absolute value is larger than 90 degrees with respect to the line supply direction 81 when viewed from the perpendicular direction with respect to the surface of the mother substrate. This relationship will be described with reference to fig. 4. Fig. 4 is a view schematically showing the gas flow-splitting portion 73 in the case where the 1 st gas ejection hole 75 is not formed directly below the thread supply line 72 when viewed from the perpendicular direction to the surface of the matrix, and is a view of the gas flow-splitting portion 73 when viewed from the perpendicular direction to the surface of the matrix (the Z-axis direction in fig. 1). When the absolute value of the angle α formed by the line supply direction 81 and the center axis direction 82 of the 1 st gas ejection hole 75 as viewed in the vertical direction with respect to the surface of the matrix is an angle smaller than 90 degrees and the absolute value of the angle β formed by the line supply direction 81 and the center axis direction 83 of the 2 nd gas ejection hole 76 as viewed in the vertical direction with respect to the surface of the matrix is an angle larger than 90 degrees, if the shielding gas is ejected from the 2 nd gas ejection hole 76 toward the intersection P, the supply of the shielding gas is blocked by the line 2 and the rear surface region B is generated, but if the shielding gas is ejected from the 1 st gas ejection hole 75 toward the intersection P, the supply of the shielding gas to the rear surface region B is not blocked by the line 2, and therefore the shielding gas can be supplied to the entire processing region a.

According to the above configuration, even if the back surface region B is generated in the processing region a by shielding the shielding gas ejected from one gas ejection hole by the wire 2, the welding bead 3 and its vicinity can be filled with the shielding gas atmosphere by supplying the shielding gas to the back surface region B by the shielding gas ejected from the other gas ejection hole, and oxidation of the welding bead 3 and the base material 4 can be prevented.

In embodiment 1 of the present invention, the description has been made using the annular gas flow dividing portion 73 having the 1 st gas ejection hole 75 and the 2 nd gas ejection hole 76, but this is an example, and it is only necessary to include the 1 st gas ejection hole 75 and the 2 nd gas ejection hole 76 and have at least 2 or more gas ejection holes, and for example, as shown in fig. 5, the shielding gas is ejected toward the intersection P, and a configuration may be adopted in which the 1 st gas ejection hole 75, the 2 nd gas ejection hole 76, and the 4 th gas ejection hole 84 are provided in the gas flow dividing portion 73. The shape of the gas flow dividing portion 73 is not limited to a ring shape, and may be any shape as long as it has gas ejection holes so as to eject the shielding gas toward the processing region a from a plurality of directions without interfering with the irradiation of the laser beam 1 to the processing region a, and the shielding gas is divided and supplied to each of the gas ejection holes.

In the present embodiment, the structure in which the line supply line 72 and the 1 st gas supply line 74 are integrated is described as an example, but the structure is not limited to the structure in which the line supply line 72 and the 1 st gas supply line 74 are integrated, and the line supply line 72 and the 1 st gas supply line 74 may be separated.

Fig. 6 is a hardware configuration diagram of the control device 20 included in the laser metal modeling apparatus 100. The control functions of the control device 20 are implemented by a processor executing programs stored in the memory 102. The processor 101 is a cpu (central Processing unit), a Processing device, an arithmetic device, a microprocessor, a microcomputer, or a dsp (digital Signal processor). The functions of the control device 20 are implemented by the processor 101 and software, firmware or a combination of software and firmware. The software or firmware is described as a program and stored in the memory 102. The Memory 102 is a built-in Memory such as a nonvolatile or volatile semiconductor Memory, for example, a ram (random Access Memory), a rom (Read Only Memory), a flash Memory, an eprom (Erasable Programmable Read Only Memory), an EEPROM (registered trademark) (Electrically Erasable Programmable Read Only Memory), or the like. The display 103 displays a display screen related to the control of the laser metal modeling apparatus 100.

Embodiment 2.

Embodiment 2 describes a shield gas nozzle for metal forming that suppresses air from entering the periphery of a weld bead and has a high oxidation preventing effect. The same portions as those in embodiment 1 will not be described, and portions different from those in embodiment 1 will be described.

Fig. 7 is a schematic view of a shield gas nozzle 70a for metal forming according to embodiment 2.

Fig. 7(a) is a view seen from a vertical direction (Z-axis direction in fig. 1) with respect to the surface of the mother substrate, fig. 7(b) is a view seen from a horizontal direction (X-axis direction in fig. 1) with respect to the surface of the mother substrate, and fig. 7(c) is a view seen from a horizontal direction (Y-axis direction in fig. 1) with respect to the surface of the mother substrate.

The nozzle 71a of the shield gas nozzle 70a for metal forming according to embodiment 2 is configured to further include a 3 rd gas ejection hole 85 for ejecting the shield gas from a position higher than the 1 st gas ejection hole 75 and the 2 nd gas ejection hole 76 through the space above the intersection P, and a 2 nd gas supply line 86 as a path for supplying the shield gas to the 3 rd gas ejection hole 85, in the nozzle 71 of the shield gas nozzle 70 for metal forming according to embodiment 1. The 3 rd gas ejection hole 85 is formed in the nozzle 71a at a position higher than the 1 st gas ejection hole 75 and the 2 nd gas ejection hole 76 with respect to the surface of the base material. The 3 rd gas ejection hole 85 ejects the shielding gas from this position in the horizontal direction with respect to the surface of the mother substrate, thereby forming a gas curtain above the intersection P.

The shielding gas jetted from the 3 rd gas jetting hole 85 is not directly supplied to the machining area a, but forms a gas curtain, and has a function of a gas curtain for preventing the intrusion of the outside gas, so that the intrusion of the atmosphere directly above the machining area a can be prevented, and the weld bead 3 and the vicinity thereof can be stably secured by the shielding gas. The flow of the shielding gas ejected from the 3 rd gas ejection hole 85 is preferably a laminar flow having a characteristic of a smooth and stable flow. The flow of gas ejected from the 3 rd gas ejection hole 85 is made laminar or turbulent, and is determined by the magnitude of reynolds number expressed by the following equation.

Re＝ρ×L×U/μ···(1)

Here, Re is Reynolds number and ρ is density of gas [ kg/m ]³]L is a representative length [ m ]]U is the flow velocity [ m/s]Mu is a viscosity coefficient [ Pa.s ] of the gas]. For example, the outlet of the 3 rd gas ejection hole 85 is formed to have a length of 1.0X 10 on the short side 87^－3[m]And the length of the long side 88 is 30.0X 10^－3[m]In the case of a rectangular shape of (2), if the aspect ratio is 1: since 30 has a sufficiently large aspect ratio, the length of the short side 87 as the representative length is 1.0 × 10^－3[m]. If Re is 1000, argon (Ar) is used as the protective gas, and the gas density ρ is 1.076[ kg/m ] at an atmospheric temperature of 25 ℃³]The gas viscosity coefficient μ was 0.0227 × 10^－3[Pa·s]When U is found to be about 21[ m/s ] according to the formula (1)]. That is, if the shielding gas is injected from the 3 rd gas injection hole 85 at about 21[ m/s ]]The discharge at the flow velocity of (3) can be a laminar flow. That is, the controller 20 controls the flow rate of the shielding gas so that the shielding gas discharged from the 3 rd gas discharge hole 85 becomes a laminar flow. The outlet shape of the 3 rd gas ejection hole 85 is not limited to the shape shown in fig. 7 as long as it is a shape that has a numerical value indicating laminar flow when the reynolds number is obtained by using equation (1).

As described above, according to the present embodiment, the shielding gas is ejected from the 3 rd gas ejection hole 85 in the horizontal direction with respect to the surface of the base material, and the gas curtain is formed above the intersection P, whereby the atmospheric shielding property to the processing region and the vicinity thereof can be improved, and the weld bead and the base material can be prevented from being oxidized.

Embodiment 3.

In embodiment 2, a description is given of a shield gas nozzle that suppresses air from mixing into the periphery of the weld bead and has a high oxidation preventing effect, but in embodiment 3, a description is given of a modification of embodiment 2. The same portions as those in embodiments 1 and 2 will not be described, and portions different from those in embodiments 1 and 2 will be described.

Fig. 8 is a schematic view of a typical shield gas nozzle 70b for metal fabrication according to embodiment 3.

Fig. 8(a) is a view seen from a vertical direction (Z-axis direction in fig. 1) with respect to the surface of the mother substrate, fig. 8(b) is a view seen from a horizontal direction (X-axis direction in fig. 1) with respect to the surface of the mother substrate, and fig. 8(c) is a view seen from a horizontal direction (Y-axis direction in fig. 1) with respect to the surface of the mother substrate.

The nozzle 71b has, inside thereof, a wire supply line 72 as a path for supplying the wire 2 to the processing area a at an inclination angle θ with respect to a surface of the base material on which the weld bead 3 is formed, a 1 st gas ejection hole 75a for ejecting the shielding gas to the processing area a, a 1 st gas supply line 74a as a path for supplying the shielding gas to the 1 st gas ejection hole 75a, a 3 rd gas ejection hole 85 for ejecting the shielding gas from a position higher than the 1 st gas ejection hole 75a and the 2 nd gas ejection hole 76a through the upper space of the intersection point P, and a 2 nd gas supply line 86 as a path for supplying the shielding gas to the 3 rd gas ejection hole 85. The 3 rd gas ejection hole 85 is formed in the nozzle 71b at a position higher than the 1 st gas ejection hole 75a and the 2 nd gas ejection hole 76a with respect to the surface of the base material. The 3 rd gas ejection hole 85 ejects the shielding gas from this position in the horizontal direction with respect to the surface of the mother substrate, thereby forming a gas curtain above the intersection P.

Further, the outlet of the 1 st gas ejection hole 75a is formed at a position closer to the base material surface than the position of the outlet of the wire supply wire 72, and is formed to eject the shielding gas to the intersection P at an angle smaller than or equal to the inclination angle θ with respect to the base material surface. The shape of the 1 st gas ejection hole 75a is preferably a shape that expands toward the outlet of the gas ejection hole so that the weld bead 3 formed in the machining region a and its vicinity are covered with the shielding gas.

The metal forming shield gas nozzle 70b includes a gas direction changing portion 90 that changes the direction of the shield gas ejected from the 3 rd gas ejection hole 85 to the upper space of the processing area a, and ejects the shield gas to the processing area a. The gas direction changing unit 90 includes a 2 nd gas discharge hole 76a for discharging the shielding gas to the processing area a, a gas inlet 91 for introducing the shielding gas discharged from the 3 rd gas discharge hole 85 to the upper space of the processing area a, and a gas direction changing line 92 for changing the direction of the shielding gas introduced from the gas inlet 91 and supplying the shielding gas to the 2 nd gas discharge hole 76 a. In order to facilitate introduction of the shielding gas ejected from the 3 rd gas ejection hole 85 to the upper space of the processing area a in the horizontal direction with respect to the surface of the workpiece, the gas introduction port 91 is formed in the gas direction changing portion 90 at a position on the extension line of the ejection direction of the 3 rd gas ejection hole 85. The shape of the 2 nd gas ejection hole 76a is preferably a shape that expands toward the outlet of the gas ejection hole so that the weld bead 3 formed in the machining region a and its vicinity are covered with the shielding gas.

As described above, according to the present embodiment, the shielding gas is ejected from the 3 rd gas ejection hole 85 in the horizontal direction with respect to the surface of the base material, and the direction of the shielding gas ejected from the 3 rd gas ejection hole 85 and passing through the upper portion of the intersection P is changed, and the shielding gas is ejected from the 2 nd gas ejection hole 76a, whereby the shielding gas can be supplied to the rear surface region as well while forming a gas curtain above the intersection P, and the atmosphere shielding property to the processing region a and the vicinity thereof can be improved, and oxidation of the weld bead 3 and the base material 4 can be prevented.

In embodiment 3 of the present invention, the nozzle 71b having the 1 st gas ejection hole 75a and the gas direction changing unit 90 having the 2 nd gas ejection hole 76a have been described, but this is an example, and the nozzle 71b may have the 1 st gas ejection hole 75a and the other gas ejection holes, and the gas direction changing unit 90 may have the 2 nd gas ejection hole 76a and the other gas ejection holes, for example, as long as the nozzle includes the 1 st gas ejection hole 75a and the 2 nd gas ejection hole 76a and has at least 2 gas ejection holes or more.

In embodiment 3 of the present invention, an example is shown in which the outlet shapes of the 1 st gas ejection hole 75a and the 2 nd gas ejection hole 76a are rectangular. The outlet shape of the gas ejection hole is preferably a rectangular shape because a wide range of the weld bead and the vicinity thereof can be easily covered with the shielding gas, but is not limited to a rectangular shape as long as the weld bead and the vicinity thereof can be filled with the shielding gas atmosphere. The outlet shape of the 3 rd gas ejection hole 85 is not limited to the shape shown in fig. 8, as long as it is a shape that has a numerical value indicating laminar flow when the reynolds number is obtained by using equation (1). The flow of the shielding gas discharged from the 1 st gas discharge hole 75a and the 2 nd gas discharge hole 76a is preferably a laminar flow, and the conditions that can realize the laminar flow described in embodiment 1 can be satisfied.

In the present embodiment, the structure in which the line supply line 72 and the 1 st gas supply line 74a are integrated is described as an example, but the structure is not limited to the structure in which the line supply line 72 and the 1 st gas supply line 74a are integrated, and the line supply line 72 and the 1 st gas supply line 74a may be separated.

The configuration described in the above embodiment is an example of the content of the present invention, and may be combined with other known techniques, and a part of the configuration may be omitted or modified without departing from the scope of the present invention.

Description of the reference numerals

1 laser, 2 lines, 3 passes, 4 base metal, 5 stages, 6 laser heads, 7 optical transmission paths, 10 laser oscillators, 20 control devices, 30 processing heads, 31 processing head bodies, 40 line supply devices, 50 shielding gas supply devices, 60 drive devices, 61X-axis drive devices, 62Y-axis drive devices, 63Z-axis drive devices, 70a, 70b metal forming shielding gas nozzles, 71a, 71b nozzles, 72 line supply lines, 73 gas split portions, 74a 1 st gas supply lines, 75a 1 st gas ejection holes, 76a 2 nd gas ejection holes, 77 split gas supply lines, 78 split points, 81 line supply directions, 82 center axis directions of 1 st gas ejection holes, 83 center axis directions of 2 nd gas ejection holes, 84 th 4 th gas ejection holes, 85 rd gas ejection holes, 86 nd 2 gas ejection holes, 87 short side, 88 long side, 90 gas direction changing part, 91 gas inlet, 92 gas direction changing line, 100 laser metal shaping device, 101 processor, 102 memory, 103 display, A processing area, B back area, P cross point.