Additive manufacturing devices and processing heads

Abstract

The additive manufacturing device comprises: a wire material supply nozzle (6) which supplies a linear material to a processing object (23); and a processing head (3) which irradiates a laser beam (L) to the material supplied to the processing object (23) and sprays a protective gas (G) from a supply source of the protective gas (G), wherein the processing head (3) comprises: a cylindrical pipeline (301) which allows the laser beam (L) to pass through and extends in the direction of travel of the laser beam (L); and a gas supply port which supplies the protective gas (G) from the supply source to the pipeline (301).

Description

Technical Field

[0001] The present invention relates to an additive manufacturing device and a processing head for manufacturing a shaped object by irradiating a material supplied to a processing object with a laser beam to melt the material and solidify the material. Background Art

[0002] An additive manufacturing device is a device that uses a heat source to melt the metal material supplied to the processing object, and stacks the solidified processed object on the processing object to process the object. During processing, the processed object is exposed to the atmosphere at high temperature and is therefore easily oxidized. When the processed object is oxidized, the quality of the formed object may deteriorate or the processing may become unstable. In particular, in the processing performed by the additive manufacturing device, the processed object is stacked, so the processed object is easy to accumulate heat, and one processing usually takes several hours. Therefore, compared with processing methods such as cladding, in the processing performed by the additive manufacturing device, there is a tendency for the processed object to be easily oxidized.

[0003] Therefore, as one of the methods for suppressing oxidation of the processed product, the following method has been used in the past:

[0004] That is, an inert gas is injected as a shielding gas to a processing point to protect the processing point from the influence of the atmosphere, i.e., oxygen. However, when the shielding gas injected from the gas nozzle is turbulent, it will be drawn into the atmosphere, i.e., oxygen, and easily oxidized. Therefore, a gas nozzle capable of suppressing the occurrence of turbulence is desired.

[0005] Patent document 1 discloses a nozzle for optical processing, which comprises: a light path component that constitutes a light path through which light such as a laser beam passes; and a flow path component that is disposed around the light path component and has a gas flow path through which a carrier gas containing powder flows. In the nozzle for optical processing described in Patent document 1, light passes through the light path constituted by the light path component and is emitted from the front end of the nozzle for optical processing toward a processing object, and the carrier gas containing powder passes through the gas flow path constituted by the flow path component and is ejected from the front end of the nozzle for optical processing toward a processing object.

[0006] Patent Document 1: International Publication No. 2016 / 135907 Summary of the invention

[0007] In addition, when a carrier gas containing powder is made to flow through the same path as the light, the powder is melted in the path by the light, so the structure of the processing head is made independent of the light path and the gas flow path, as described in Patent Document 1. If the light path and the gas path are made independent of each other, the processing head will be complicated. In addition, the carrier gas is supplied through an axis different from the light path, so there is a problem that the rectification effect of the gas is impaired, and turbulence occurs at the irradiation position of the light.

[0008] The present invention is proposed in view of the above situation, and its purpose is to provide an additive manufacturing device that can suppress the occurrence of gas turbulence with a simple structure compared with the past when processing while irradiating a material supplied to a processing object with a laser beam and supplying gas.

[0009] In order to solve the above-mentioned problems and achieve the purpose, the present invention is an additive manufacturing device, which comprises: a wire supply nozzle, which supplies linear material to a processing object; and a processing head, which irradiates a laser beam to the material supplied to the processing object and sprays a protective gas from a protective gas supply source. The processing head of the additive manufacturing device comprises: a cylindrical pipeline, which allows the laser beam to pass through and extends in the direction of travel of the laser beam; and a gas supply port, which supplies the protective gas from the supply source to the pipeline.

[0010] Effects of the Invention

[0011] The additive manufacturing apparatus according to the present invention has the effect of suppressing the occurrence of gas turbulence with a simple structure compared with the related art when processing is performed while supplying gas while irradiating a material supplied to a processing object with a laser beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a diagram showing the structure of the additive manufacturing apparatus according to the first embodiment.

[0013] Figure 2 This is a cross-sectional view schematically showing an example of the structure of the processing head according to the first embodiment.

[0014] Figure 3 This is a cross-sectional view schematically showing an example of the structure near the gas supply nozzle of the processing head involved in the second embodiment.

[0015] Figure 4 This is a cross-sectional view schematically showing an example of the structure of the vicinity of the gas supply nozzle of the processing head involved in the third embodiment.

[0016] Figure 5 This is a cross-sectional view schematically showing an example of the structure of the vicinity of the gas supply nozzle of the processing head involved in the fourth embodiment.

[0017] Figure 6 This is a perspective view showing an example of the structure of a gas supply nozzle of a processing head involved in the fourth embodiment.

[0018] Figure 7 This is a cross-sectional view schematically showing an example of the structure of a processing head according to the fifth embodiment. DETAILED DESCRIPTION

[0019] Hereinafter, an additive manufacturing apparatus and a processing head according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0020] Implementation method 1.

[0021] Figure 1 1 is a diagram showing the structure of an additive manufacturing device according to Embodiment 1. The additive manufacturing device 100 is a machine tool for manufacturing a three-dimensional object by adding a molten filler material to a processing object 23. The additive manufacturing device 100 melts the filler material by irradiating a heat source. In Embodiment 1, the heat source is a laser beam L. In Embodiment 1, the filler material is a linear metal material.

[0022] The additive manufacturing apparatus 100 partially melts the front end of the wire 5, which is a filler material supplied to the processing object 23, by the laser beam L, and brings the molten material of the wire 5 into contact with the processing object 23, thereby forming a weld bead 21. The weld bead 21 is a solidified material of the wire 5 melted by irradiation with the laser beam L. The additive manufacturing apparatus 100 manufactures a shaped object by laminating the weld bead 21 on the substrate 20. Figure 1 The substrate 20 shown is a plate. The substrate 20 may be an object other than a plate. The processing object 23 is an object to which a molten filler material is added, and is the substrate 20 or a weld bead 21 on the substrate 20. The molten weld bead 22 is a molten portion of the weld bead 21.

[0023] The X-axis, Y-axis, and Z-axis are three axes perpendicular to each other. The X-axis and Y-axis are axes in the horizontal direction. The Z-axis is an axis in the vertical direction. The Z-axis direction is the direction in which the weld bead 21 is stacked, that is, the stacking direction.

[0024] The additive manufacturing apparatus 100 includes a laser oscillator 1 , a laser output controller 11 , a processing head 3 , a gas flow rate regulator 12 , a wire reel 4 , a wire supply nozzle 6 , a table 8 , a drive controller 13 , and a numerical control (NC) device 17 .

[0025] The laser oscillator 1 outputs a laser beam L as a heat source. The laser beam L output by the laser oscillator 1 is transmitted to the processing head 3 via an optical cable 2 as an optical transmission path. The laser output controller 11 controls the laser oscillator 1, thereby adjusting the output of the laser beam L of the laser oscillator 1, that is, the laser output.

[0026] The processing head 3 is connected to the optical cable 2 via a connector not shown in the figure, and emits the laser beam L toward the processing object 23. The processing head 3 can move in each direction of the X-axis direction, the Y-axis direction, and the Z-axis direction. The processing head 3 has a collimating optical system that parallelizes the laser beam L and a focusing lens that converges the laser beam L. The collimating optical system and the focusing lens are omitted in the figure. The direction of the center line of the laser beam L irradiated to the processing object 23 is the Z-axis direction.

[0027] The processing head 3 is provided with a gas nozzle for spraying a shielding gas toward the processing object 23. The shielding gas is a gas that suppresses oxidation caused by the irradiation of the laser beam L at the processing point. As the shielding gas, nitrogen gas, argon gas, etc., which are inert gases, are used. The oxidation of the weld bead 21 is suppressed by spraying the shielding gas, and the formed weld bead 21 is cooled. The shielding gas is supplied from a shielding gas supply source, that is, a gas cylinder. The gas flow regulator 12 adjusts the flow rate of the shielding gas. The illustration of the gas nozzle and the gas cylinder is omitted. As described above, in Embodiment 1, the processing head 3 irradiates the laser beam L to the wire 5 supplied to the processing object 23, and sprays the shielding gas from the shielding gas supply source.

[0028] The wire reel 4 is a supply source of the wire 5. The wire 5 is wound on the wire reel 4. The wire supply nozzle 6 is fixed to the processing head 3 by a support member 7. Therefore, the wire supply nozzle 6 moves together with the movement of the processing head 3. The wire supply nozzle 6 supplies the wire 5 to the processing object 23. The wire supply nozzle 6 sends the wire 5 from the wire reel 4 toward the processing object 23. In addition, the wire supply nozzle 6 pulls the sent wire 5 back in the direction of the wire reel 4. The direction in which the wire 5 is supplied is a direction inclined with respect to the direction in which the laser beam L is emitted from the processing head 3.

[0029] The worktable 8 fixes and supports the substrate 20. In one example, the worktable 8 can rotate about the Z axis and about the Y axis. The worktable 8 rotates about the Y axis, thereby changing the inclination of the worktable 8. That is, the posture of the substrate 20 fixed to the upper surface can be changed by the movement of the worktable 8. The additive manufacturing apparatus 100 changes the posture of the substrate 20 and moves the processing head 3, thereby moving the irradiation position of the laser beam L in the processing object 23.

[0030] The drive controller 13 includes a machining head drive unit 14 that drives the machining head 3 , a wire supply drive unit 15 that drives the wire supply nozzle 6 , and a table drive unit 16 that drives the table 8 .

[0031] The NC device 17 controls the entire additive manufacturing device 100 according to the processing program. The NC device 17 outputs a laser output command to the laser output controller 11, thereby controlling the laser oscillator 1. The NC device 17 outputs an axis command to the processing head drive unit 14, thereby controlling the processing head 3. The NC device 17 sends a supply command to the wire supply drive unit 15, thereby controlling the wire supply nozzle 6. The NC device 17 outputs a rotation command to the workbench drive unit 16, thereby controlling the workbench 8. The NC device 17 outputs a gas supply command to the gas flow regulator 12, thereby controlling the flow rate of the shielding gas.

[0032] Next, the processing head 3 used in the additive manufacturing apparatus 100 according to the first embodiment will be described. Figure 2 It is a cross-sectional view schematically showing an example of the structure of the machining head according to Embodiment 1. The machining head 3 includes a machining head body 31 , a gas jet nozzle 32 , and a protection plate 33 .

[0033] The processing head body 31 is a cylindrical component having a pipeline 311 extending in the direction of travel of the laser beam L, that is, the Z-axis direction. In one example, the processing head body 31 is made of aluminum. The laser beam L passes through the pipeline 311, and the protective gas G flows through it. That is, the laser beam L and the protective gas G pass through the same pipeline 311. The outer diameter of the processing head body 31 and the diameter of the pipeline 311 are the same in the Z-axis direction. The outer shape of the processing head body 31 and the shape of the pipeline 311 can be cylindrical or polygonal square cylinder.

[0034] The processing head main body 31 has a through hole 312 at the upper part, which is a gas supply port for supplying the shielding gas G to the pipeline 311. A pipe 35 such as a hose connected to a gas cylinder (not shown) is fixed to the through hole 312 through a connecting member (not shown). Thus, the shielding gas G flowing from the through hole 312 via the pipe 35 is supplied to the pipeline 311 of the processing head main body 31. The through hole 312 is preferably provided at the upper part of the processing head main body 31, that is, near the incident position of the laser beam L. The through hole 312 is preferably within a range of 1 / 3 of the length of the processing head 3 in the Z-axis direction from the upper surface of the processing head 3. The reason is that, when the through hole 312 exists outside the range of 1 / 3 of the length of the processing head 3 from the upper surface of the processing head 3, the distance that the shielding gas G flows down in the pipeline 311 becomes short, and it is difficult to rectify until it reaches the gas injection nozzle 32. In one example, the through hole 312 is formed by mechanical processing on the side surface of the processing head main body 31. In addition, here, the through hole 312 is formed in a direction perpendicular to the side surface of the processing head main body 31 parallel to the traveling direction of the laser beam L. That is, the through hole 312 is provided in a manner that the extending direction of the through hole 312 is parallel to the direction perpendicular to the side surface of the processing head main body 31.

[0035] The gas injection nozzle 32 is a component that is provided at the end of the worktable 8 side of the processing head body 31, and emits a laser beam L to the processing point 231 and injects a shielding gas G. The processing point 231 is the irradiation position of the laser beam L on the processing object 23, and is the area where the weld bead 21 is added. The wire 5 from the wire supply nozzle 6 is also supplied to the processing point 231. The gas injection nozzle 32 is a hollow component having a pipeline 321 extending in the Z-axis direction. The diameter of the pipeline 321 on the worktable 8 side is smaller than the diameter on the processing head body 31 side. The diameter of the pipeline 321 can be continuously reduced toward the worktable 8 side, or it can be reduced in a step shape. In one example, the gas injection nozzle 32 is composed of a hollow frustum-shaped component. The gas injection nozzle 32 is composed of aluminum in one example. In addition, the gas injection nozzle 32 can be formed integrally with the processing head body 31, or it can be connected to the processing head body 31 by welding or the like.

[0036] Furthermore, the conduit 301 of the machining head 3 includes a conduit 311 of the machining head main body 31 and a conduit 321 of the gas jet nozzle 32 .

[0037] The protective plate 33 is provided to block the opening of the end of the processing head main body 31 on the opposite side to the gas injection nozzle 32. The protective plate 33 is composed of a member transparent to the wavelength of the laser beam L. In one example, the protective plate 33 is composed of glass. The protective plate 33 has a connector 331 for fixing the optical cable 2 on the upper surface. The protective plate 33 is a member for protecting the connector 331 from sputtering or smoke generated when the laser beam L is irradiated to the wire 5 in the additive manufacturing device 100.

[0038] As described above, the machining head 3 includes the conduit 301 extending in the Z-axis direction, and has a structure in which the end portion on the incident side of the laser beam L is closed. The incident surface of the laser beam L corresponds to the protective plate 33 .

[0039] exist Figure 2In FIG. 2 , the optical path of the laser beam L is depicted by a solid line, and the flow of the shielding gas G is depicted by a dashed line. The laser beam L is guided from the optical cable 2 to the pipeline 301 of the processing head 3 via the connector 331. Moreover, the laser beam L is emitted from the front end of the gas injection nozzle 32 in the Z-axis direction inside the pipeline 301. In addition, the shielding gas G is supplied from the through hole 312 to the pipeline 301 of the processing head 3 via the pipe 35. The shielding gas G flows downward from the through hole 312 toward the gas injection nozzle 32. That is, the shielding gas G flows downward in the Z-axis direction in the pipeline 301 that is the same as the pipeline 301 through which the laser beam L passes. Moreover, the shielding gas G is injected from the gas injection nozzle 32 toward the processing point 231. The shielding gas G supplied from the through hole 312 is rectified as it flows down the pipeline 301, and is injected from the gas injection nozzle 32 to reach the processing point 231 in a laminar flow state.

[0040] The supply position of the shielding gas G in the pipeline 301 is arranged near the incident position of the laser beam L, and the injection position of the shielding gas G is the same as the emission position of the laser beam L, so the macroscopic flow direction of the shielding gas G in the pipeline 301 is parallel to the optical path of the laser beam L. In addition, the shielding gas G flows down inside the cylindrical pipeline 301, so it is considered that the shielding gas G is rectified in the pipeline 301.

[0041] As a result, while the laser beam L is irradiated to the processing point 231 , the shielding gas G is injected in a laminar flow state to the region including the laser beam L, thereby suppressing the generation of turbulence due to the entrainment of oxygen in the surrounding atmosphere.

[0042] Whether it is laminar flow or turbulent flow can be determined by the Reynolds number. 0 , when the diameter of the nozzle is d and the dynamic viscosity coefficient of the airflow is v, the calculation is performed by the following formula (1). In addition, in the case of a fluid flowing through a circular tube, the representative velocity can be an average velocity.

[0043] R=U 0 d / v· · · (1)

[0044] Through experiments and simulations, it can be known that by setting the Reynolds number R of the nozzle area of ​​the through hole 312 to be less than or equal to 10100, the shielding gas G ejected from the gas injection nozzle 32 becomes a laminar flow. That is, when the Reynolds number R of the nozzle area of ​​the through hole 312 exceeds 10100, the shielding gas G ejected from the gas injection nozzle 32 sometimes becomes a turbulent flow. As described above, in a turbulent flow, oxygen is easily drawn in at the processing point 231, but in a laminar flow, oxygen is not easily drawn in, and the processing quality is improved. Therefore, if the Reynolds number R of the nozzle area of ​​the through hole 312 is less than or equal to 10100, the shielding gas G can be rectified in the pipeline 301 up to the gas injection nozzle 32. As shown in formula (1), by calculating the representative velocity U of the shielding gas G, 0 Alternatively, the Reynolds number R can be controlled by controlling the diameter d of the through hole 312 .

[0045] The processing head 3 of the first embodiment is composed of a cylindrical component having a pipeline 301 extending in the traveling direction of the laser beam L through which the laser beam L passes, and is connected to a pipe 35 from a supply source of the shielding gas G, and the pipeline 301 has a through hole 312 for supplying the shielding gas G. That is, the shielding gas G flows in the same pipeline 301 as the laser beam L. As a result, it is not necessary to separately provide a component for constituting a flow path for flowing the shielding gas G independently of the pipeline through which the laser beam L passes, as in the prior art, so that a simple structure can be realized at a low price. In addition, the shielding gas G flows down in the same pipeline 301 as the laser beam L, thereby rectifying the shielding gas G in the pipeline 301, and the shielding gas G can be sprayed to the processing point 231 in a laminar flow state. By setting it as a laminar flow, oxygen is not easily involved at the processing point 231, the processing quality is improved, and stable processing can be performed. That is, when processing the wire 5 supplied to the processing object 23 while irradiating the laser beam L and supplying the shielding gas G, there is an effect that the generation of turbulence of the shielding gas G can be suppressed with a simple structure compared with the related art.

[0046] In particular, by setting the Reynolds number R in the through hole 312 to be less than or equal to 10100, the shielding gas G flowing down in the pipe 301 can be rectified, and the shielding gas G sprayed toward the processing point 231 can be set to a laminar flow.

[0047] Implementation method 2.

[0048] Figure 3 It is a cross-sectional view schematically showing an example of the structure of the vicinity of the gas supply nozzle of the processing head according to Embodiment 2. In addition, the same reference numerals are attached to the same components as those of Embodiment 1, and the description thereof is omitted, and the different parts are described below.

[0049] The processing head 3 according to the second embodiment further includes a gas supply nozzle 34 connected to the through hole 312. The gas supply nozzle 34 includes a pipe connection portion 341 connected to the pipe 35 and arranged outside the side surface of the processing head main body 31, and an insertion portion 342 inserted into the through hole 312. The pipe connection portion 341 is a plate-shaped member fixed to the processing head main body 31 by a fixing member not shown. In one example, the fixing member is a bolt, which is screwed into a screw hole provided in the pipe connection portion 341 and the processing head main body 31. The insertion portion 342 is connected to one surface of the pipe connection portion 341. In addition, an internal flow path 343 is provided in a manner that the pipe connection portion 341 and the insertion portion 342 are connected. The inlet 343a of the internal flow path 343 is provided in the pipe connection portion 341, and the outlet 343b is provided in the insertion portion 342. The diameter of the outlet 343b is set smaller than the diameter of the inlet 343a. Here, an example is shown in which the diameter of the internal flow path 343 decreases in a step-like manner near the boundary between the pipe connection portion 341 and the insertion portion 342, but the diameter may also be continuously reduced. The flow outlet 343b of the gas supply nozzle 34 corresponds to the gas supply port. In addition, the position of the flow inlet 343a of the gas supply nozzle 34 and the position of the flow outlet 343b are equal in the direction of travel of the laser beam L. More specifically, the center position of the flow inlet 343a of the gas supply nozzle 34 and the center position of the flow outlet 343b are equal in the direction of travel of the laser beam L.

[0050] In the gas supply nozzle 34, the diameter of the outflow port 343b is smaller than that of the inflow port 343a, so the flow rate of the shielding gas G ejected from the gas supply nozzle 34 is larger than the flow rate of the shielding gas G flowing through the pipe 35. Therefore, when the flow rate of the shielding gas G flowing through the pipe 35 is set to be the same, if the gas supply nozzle 34 is not provided, the proportion of the shielding gas G that collides with the wall surface of the pipeline 301 opposite to the through hole 312 from the through hole 312 is small, but if the gas supply nozzle 34 is provided, the shielding gas G will collide with the wall surface of the pipeline 301 opposite to the outflow port 343b. By making the shielding gas G collide with the wall surface in the pipeline 301, the shielding gas G is diffused, the dynamic pressure is temporarily reduced, and the flow rate is reduced. In addition, the velocity distribution in the pipeline 301 becomes the same. That is, there is no imbalance in the velocity distribution in the pipeline 301, so the rectification effect is improved. As a result, the shielding gas G injected from the gas injection nozzle 32 reaches the processing point 231 in a laminar flow state.

[0051] Generally speaking, in order to make the jet flow not turbulent but laminar, any of the following methods is used, that is, reducing the flow rate of the protective gas G, or expanding the opening diameter of the processing head 3, or rectifying the protective gas G in the processing head 3. However, in order to ensure the protection performance, a certain flow rate must be ensured. In addition, if the opening diameter of the processing head 3 is increased, the possibility of collision of the object during the forming process increases, so it cannot be easily increased. In addition, in the case of rectification in the processing head 3, a diffuser or a filter is widely used, but in the processing head 3 involved in embodiment 2, the protective gas G and the laser beam L pass together in the pipeline 301. Therefore, the light path of the laser beam L will be blocked by the diffuser or the filter, so it cannot be used.

[0052] In Embodiment 2, a gas supply nozzle 34 having a smaller diameter of an outlet 343b than an inlet 343a is provided in the through hole 312. As a result, the jet of the shielding gas G from the gas supply nozzle 34 collides with the inner wall of the pipeline 301 opposite to the gas supply nozzle 34, and the velocity distribution of the shielding gas G in the pipeline 301 becomes the same, and the rectifying effect can be further improved compared with the case of Embodiment 1. As a result, the shielding gas G can be guided to the processing point 231 in a laminar flow state.

[0053] exist Figure 3 In the embodiment 1, the case where the gas supply nozzle 34 is provided in the through hole 312 is described. Figure 2 The structure of the processing head 3, or the use of Figure 3 In the structure of the gas supply nozzle 34 in which the diameter of the outlet 343b is the same as the diameter of the inlet 343a, the same effect can be obtained even if the flow rate of the protective gas G is increased. Figure 2 The structure of the processing head 3, or the use of Figure 3 In the structure of the gas supply nozzle 34 in which the diameter of the outlet 343b is the same as the diameter of the inlet 343a, when the shielding gas G is made to flow at a certain flow rate, the shielding gas G is set to a state where the wall surface of the pipeline 301 opposite to the through hole 312 does not collide. In this case, by replacing the processing head 3 with a processing head 3 having a smaller diameter of the pipeline 301, the shielding gas G ejected from the through hole 312 can collide with the wall surface of the pipeline 301 opposite to the through hole 312 even at the same flow rate. As described above, by reducing the diameter of the pipeline 301 of the processing head 3, the same effect can be obtained. In addition, in the second embodiment, by setting the Reynolds number R of the nozzle area of ​​the gas supply nozzle 34 to be less than or equal to 10100, the shielding gas G at the processing point 231 also becomes a laminar flow.

[0054] Implementation method 3.

[0055] Figure 4 It is a cross-sectional view schematically showing an example of the structure of the vicinity of the gas supply nozzle of the processing head according to Embodiment 3. In addition, the same reference numerals are attached to the same components as those of Embodiments 1 and 2, and the description thereof is omitted, and the different parts are described below.

[0056] In the processing head 3 involved in the third embodiment, the through hole 312 provided on the side of the processing head main body 31 is composed of a flow path facing obliquely upward. That is, the position of the pipeline 311 side is located higher than the position of the through hole 312 on the outside of the processing head main body 31. Specifically, the center position of the pipeline 311 side is located higher than the center position of the through hole 312 on the outside of the processing head main body 31. Figure 4 In the example of FIG. 3 , a case where a gas supply nozzle 34 is provided is shown. The through hole 312 has an opening portion having a size that allows the insertion portion 342 of the gas supply nozzle 34 to be inserted, and an opening portion having a diameter smaller than the diameter of the opening portion and extending obliquely upward from the end of the opening portion.

[0057] By the structure of the through hole 312 as described above, the shielding gas G ejected from the gas supply nozzle 34 collides with the incident surface of the laser beam L of the processing head 3, that is, the upper surface, that is, the shielding plate 33 arranged on the upper part of the processing head main body 31. In the third embodiment, the shielding gas G is also made to collide with the shielding plate 33, so that the velocity distribution of the shielding gas G in the pipeline 301 can be made the same as in the second embodiment. In addition, it is known through experiments and simulations that, compared with the case where the shielding gas G is made to collide with the wall surface of the pipeline 301 opposite to the through hole 312, the case where the shielding gas G collides with the upper surface of the processing head 3 relative to the cross section in the pipeline 301 is less uneven, and the rectification effect in the pipeline 301 is high.

[0058] According to the third embodiment, by making the shielding gas G collide with the upper surface of the processing head 3, the shielding gas G can be uniformly supplied to the nozzle surface corresponding to the end surface of the gas injection nozzle 32. As a result, the rectifying effect of the shielding gas G in the pipeline 301 of the processing head 3 can be improved compared with the case of the second embodiment. Moreover, compared with the case of the second embodiment, the shielding gas G can be supplied to the processing point 231 in a laminar flow state with an improved rectifying effect. In addition, in the third embodiment, by setting the Reynolds number R of the nozzle area of ​​the gas supply nozzle 34 to be less than or equal to 10100, the shielding gas G at the processing point 231 also becomes a laminar flow.

[0059] In addition, Figure 4, the case where the gas supply nozzle 34 is provided in a manner that the internal flow path 343 is perpendicular to the side surface of the processing head main body 31 is shown, but the gas supply nozzle 34 may be installed obliquely with respect to the side surface of the processing head 3 in a manner that the internal flow path 343 faces the upper surface of the processing head 3. In addition, a structure in which the pipe 35 is connected to the through hole 312 without providing the gas supply nozzle 34 is also possible.

[0060] Implementation method 4.

[0061] Figure 5 is a cross-sectional view schematically showing an example of a structure near a gas supply nozzle of a processing head according to Embodiment 4, Figure 6 It is a perspective view showing an example of the structure of the gas supply nozzle of the processing head according to Embodiment 4. In addition, below, the same reference numerals are attached to the same components as those of Embodiments 1 to 3, and the description thereof is omitted, and the different parts are described.

[0062] In Embodiment 4, the through hole 312 of the machining head body 31 of the machining head 3 is the same as that of Embodiments 1 and 2. That is, the through hole 312 is composed of a flow path perpendicular to the side surface of the machining head body 31. That is, the position of the outer surface of the machining head body 31 of the through hole 312 coincides with the position of the inner surface.

[0063] On the other hand, in Embodiment 4, at least a portion of the internal flow path 343 of the gas supply nozzle 34 is configured to face obliquely upward. The internal flow path 343 extends in a direction perpendicular to the side surface of the processing head main body 31 in the pipe connection portion 341, but extends obliquely upward in a manner such that the outlet 343b of the internal flow path 343 is located above the inlet 343a in the insertion portion 342. That is, the internal flow path 343 includes a first flow path component 3431 extending in a direction perpendicular to the side surface of the processing head main body 31, and a second flow path component 3432 connected to the first flow path component 3431 and extending obliquely upward.

[0064] The gas supply nozzle 34 of the above-described structure is connected to the through hole 312 of the machining head body 31 and to the piping 35, whereby, similarly to embodiments 2 and 3, the shielding gas G collides with the upper surface of the machining head 3, and the velocity distribution of the shielding gas G in the pipeline 301 can be made the same.

[0065] As described above, since the shielding gas G passes through the pipeline 301 together with the laser beam L, a plate or the like for guiding the shielding gas G cannot be provided in the pipeline 301. Therefore, the internal flow path 343 directed obliquely upward is created by the gas supply nozzle 34, so that the shielding gas G is sprayed into the pipeline 301 of the processing head 3, thereby eliminating the need for additional components in the pipeline 301, and the shielding gas G can be easily and inexpensively blown to the upper surface of the processing head 3. As a result, in the fourth embodiment, the same effects as those in the third embodiment can be obtained. In addition, in the fourth embodiment, by setting the Reynolds number R of the nozzle area of ​​the gas supply nozzle 34 to be less than or equal to 10100, the shielding gas G at the processing point 231 becomes a laminar flow.

[0066] Implementation method 5.

[0067] Figure 7 It is a cross-sectional view schematically showing an example of the structure of the processing head according to Embodiment 5. In addition, below, the same reference numerals are attached to the same components as those in Embodiments 1 to 4, and the description thereof is omitted, and the different parts are described.

[0068] The structure of the machining head body 31 of the machining head 3 according to the fifth embodiment is different from that of the first embodiment. That is, the machining head body 31 has a reduction portion 313 that reduces the cross-sectional area of ​​the pipe 311 as a flow path in a step-like manner in the path from the gas supply nozzle 34 to the gas injection nozzle 32 .

[0069] exist Figure 7 In the example shown, the processing head body 31 has: a first body component 31a having a through hole 312; a second body component 31b having a smaller cross-sectional area of ​​the pipeline 311 than the first body component 31a; and a reduction portion 313, which is provided at the boundary between the first body component 31a and the second body component 31b, so that the cross-sectional area of ​​the pipeline 311 changes in a step shape. A gas injection nozzle 32 is provided at the end of the second body component 31b. The reduction portion 313 has a surface perpendicular to the extension direction of the processing head body 31, and is a pipeline component that connects the first body component 31a and the second body component 31b.

[0070] The shielding gas G in the pipeline 301 of the processing head 3 contains a component that flows downstream along the wall surface in the pipeline 301. When the shielding gas G reaches the gas injection nozzle 32 along the wall surface in the pipeline 301, an imbalance occurs relative to the nozzle surface of the gas injection nozzle 32, which causes turbulence. In addition, it can be seen from the simulation that the flow rate of the shielding gas G component flowing along the wall surface in the pipeline 301 is fast and easily causes turbulence. Therefore, it is preferred to remove the component flowing along the wall surface in the pipeline 301 as much as possible. Therefore, if Figure 7As shown in the figure, a reduction portion 313 is provided in the processing head main body 31, whereby the reduction portion 313 becomes a barrier for the components of the shielding gas G flowing along the wall surface in the pipeline 301, and excludes the components of the shielding gas G flowing along the wall surface in the pipeline 301. That is, the components of the shielding gas G flowing along the wall surface in the pipeline 301 are suppressed from directly reaching the gas injection nozzle 32. As a result, the shielding gas G can be supplied more uniformly with respect to the nozzle surface of the gas injection nozzle 32, and the rectification effect can be improved.

[0071] exist Figure 7 , the processing head body 31 has one reduction portion 313, but it may have two or more reduction portions 313. In this case, the plurality of reduction portions 313 are provided so that the cross-sectional area of ​​the pipeline 311 decreases in a step-like manner from the gas supply nozzle 34 toward the gas injection nozzle 32.

[0072] In addition, Figure 7 , the cross-sectional area of ​​the pipeline 311 and the outer diameter of the processing head main body 31 are both reduced through the reduction portion 313 from the gas supply nozzle 34 toward the gas injection nozzle 32, but it is sufficient as long as the cross-sectional area of ​​the pipeline 311 is reduced. Therefore, it is possible to set the outer diameter of the processing head main body 31 to be constant from the gas supply nozzle 34 to the connection portion with the gas injection nozzle 32, and the cross-sectional area of ​​the pipeline 311 to be reduced.

[0073] And, in Figure 7 3 shows a case where the reduction portion 313 is provided in the processing head 3 of the second embodiment, but the reduction portion 313 may also be provided in the processing head 3 of the first, third, and fourth embodiments.

[0074] In the fifth embodiment, the processing head 3 has a reduction portion 313 that reduces the cross-sectional area of ​​the pipeline 301 in a step-like manner from the gas supply nozzle 34 toward the gas injection nozzle 32. As a result, the component of the shielding gas G that easily causes turbulence along the wall surface in the pipeline 301 can be removed, so that the rectification effect can be further improved compared with the cases of the first to fourth embodiments. As a result, the shielding gas G can be supplied more uniformly to the nozzle surface of the gas injection nozzle 32. As a result, the shielding gas G can be supplied to the processing point 231 in a laminar state. In addition, in the fifth embodiment, by setting the Reynolds number R of the nozzle area of ​​the gas supply nozzle 34 to be less than or equal to 10100, the shielding gas G at the processing point 231 also becomes a laminar flow.

[0075] The configuration described in the above embodiment is merely an example, and may be combined with other known technologies, the embodiments may be combined with each other, and part of the configuration may be omitted or changed without departing from the gist.

[0076] Description of the label

[0077] 1 laser oscillator, 2 optical cable, 3 processing head, 4 wire reel, 5 wire, 6 wire supply nozzle, 7 support member, 8 table, 11 laser output controller, 12 gas flow regulator, 13 drive controller, 14 processing head drive unit, 15 wire supply drive unit, 16 table drive unit, 17 NC device, 20 substrate, 21 weld bead, 22 molten weld bead, 23 processing object, 31 processing head main body, 31a first main body component, 31b second main body constituent part, 32 gas injection nozzle, 33 protection plate, 34 gas supply nozzle, 35 piping, 100 additional manufacturing device, 231 processing point, 301, 311, 321 pipeline, 312 through hole, 313 reduction part, 331 connector, 341 piping connection part, 342 insertion part, 343 internal flow path, 343a inlet, 343b outlet, 3431 first flow path constituent part, 3432 second flow path constituent part, G protection gas, L laser beam.

Claims

1. An additive manufacturing device, comprising: A wire material supply nozzle that supplies a wire material onto a processing object; and a processing head that irradiates the material supplied onto the processing object with a laser beam and ejects the protective gas from a protective gas supply source, The additive manufacturing device is characterized in that The processing head has: a processing head main body having a cylindrical conduit extending in a traveling direction of the laser beam and passing the laser beam, and a gas supply port for supplying the shielding gas from the supply source to the cylindrical conduit; and a gas jet nozzle disposed at an end of the processing head main body on the processing object side and having a hollow pipe having a smaller diameter on the processing object side than the diameter on the processing head main body side, The gas supply port is provided at an upper portion of the machining head main body.

2. The additive manufacturing device according to claim 1, characterized in that: The gas supply port is a through hole that penetrates a side surface of the processing head parallel to a traveling direction of the laser beam.

3. The additive manufacturing device according to claim 2, characterized in that: The through hole penetrates the side surface in a direction perpendicular to the side surface.

4. The additive manufacturing device according to claim 2, characterized in that: The position of the through hole on the cylindrical conduit side is located closer to the incident surface of the laser beam of the processing head than the position outside the processing head.

5. The additive manufacturing device according to claim 4, characterized in that The processing head also has a gas supply nozzle having an internal flow path. The gas supply nozzle is connected to the through hole.

6. The additive manufacturing device according to claim 1, characterized in that: The processing head also has a gas supply nozzle having an internal flow path. The gas supply nozzle is provided in a through hole provided on a side surface of the processing head parallel to the traveling direction of the laser beam. The outflow port of the gas supply nozzle corresponds to the gas supply port.

7. The additive manufacturing device according to claim 6, characterized in that The inlet and the outlet of the gas supply nozzle are located at the same position in the traveling direction of the laser beam.

8. The additive manufacturing device according to claim 6, characterized in that: The gas supply nozzle is configured such that at least a portion of the internal flow path thereof is directed obliquely upward. The outlet of the gas supply nozzle is located closer to the incident surface of the laser beam of the processing head than the inlet of the gas supply nozzle in the traveling direction of the laser beam.

9. The additive manufacturing device according to any one of claims 1 to 8, characterized in that: The processing head has a reducing portion that reduces the cross-sectional area of ​​the cylindrical pipe in a step-like manner toward the traveling direction of the laser beam.

10. The additive manufacturing device according to any one of claims 1 to 8, characterized in that: The Reynolds number of the nozzle area of ​​the gas supply port is less than or equal to 10100.

11. The additive manufacturing device according to claim 9, characterized in that: The Reynolds number of the nozzle area of ​​the gas supply port is less than or equal to 10100.

12. A processing head that irradiates a linear material supplied from a wire material supply nozzle to a processing object with a laser beam and sprays a shielding gas from a shielding gas supply source, The processing head is characterized by having: a processing head main body having a cylindrical conduit extending in a traveling direction of the laser beam and passing the laser beam, and a gas supply port for supplying the shielding gas from the supply source to the cylindrical conduit; and a gas jet nozzle disposed at an end of the processing head main body on the processing object side and having a hollow pipe having a smaller diameter on the processing object side than the diameter on the processing head main body side, The gas supply port is provided at an upper portion of the machining head main body.

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