Laser processing machine

Abstract

Provided is a laser processing machine that suppresses or prevents foreign matter from colliding with a protective glass. The laser processing machine includes a laser emission portion that emits laser light and has a protective glass through which the laser light can pass, and a cylindrical housing that is attached to the laser emission portion and is disposed so as to surround an optical path of the laser light emitted from the laser emission portion. The housing includes a first opening end portion that faces the protective glass, a second opening end portion that is on the opposite side from the first opening end portion, and a first blowout portion that is disposed on the entire circumference of the inside of the first opening end portion and blows out gas toward the central axis of the housing.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a laser processing machine. BACKGROUND

[0002] There is known a laser welding device in which a protective glass is disposed on a laser scanner in order to prevent spatters flying from a processing point at the time of laser welding from colliding with a mirror or a lens of a laser optical system (for example, Patent Literature 1). The laser welding device prevents the spatters from adhering to the protective glass by flowing air in a direction that crosses a light path of the laser.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2018-202441 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] However, the conventional technology sometimes fails to completely prevent the attachment of foreign matters to the protective glass. As a result, it is sometimes necessary to perform replacement of the protective glass. Therefore, a technology for improving the attachment of foreign matters to the protective glass is required.

[0008] The present disclosure can be implemented as follows.

[0009] (1) According to one embodiment of the present disclosure, there is provided a laser processing machine. The laser processing machine includes a laser emission portion configured to emit a laser, having a protective glass through which the laser can pass, and a cylindrical housing mounted to the laser emission portion and configured to surround a light path of the laser emitted from the laser emission portion. The housing includes a first end portion facing the protective glass, a second end portion on an opposite side from the first end portion, and a first blow-out portion provided on an entire circumference of an inner side of the first end portion and configured to blow out a gas toward a central axis of the housing.

[0010] According to the laser processing machine of this embodiment, a gas flow covering the protective glass can be generated in an inner space of the housing, and the attachment of foreign matters such as spatters and smoke to the protective glass can be suppressed or prevented.

[0011] (2) In the laser processing machine of the above embodiment, the housing can further include a first supply path provided on an entire circumference of an inner side of the housing and configured to supply the gas to the first blow-out portion.

[0012] According to the laser processing machine of this embodiment, a flow path for efficiently guiding the gas to the first blow-out portion can be provided by using the housing.

[0013] (3) In the laser processing machine of the above aspect, it can be possible that the housing further includes a plurality of first gas introduction ports for introducing gas to the first supply path.

[0014] According to the laser processing machine of this aspect, the gas is introduced from a plurality of positions with respect to the first supply path, whereby it is possible to suppress the pressure deviation of the first supply path as compared with the case where the gas is introduced to the first supply path from a single first gas introduction port.

[0015] (4) In the laser processing machine of the above aspect, it can be possible that the first supply path includes a plurality of shunt portions for shunting the gas flowing inside the housing.

[0016] According to the laser processing machine of this aspect, it is possible to direct the gas in the desired direction by a simple configuration as compared with the case where a pipe is provided inside the housing.

[0017] (5) In the laser processing machine of the above aspect, it can be possible that the plurality of shunt portions include: a first shunt portion provided in the vicinity of each of the plurality of first gas introduction ports in the first supply path, for flowing the gas introduced from the plurality of first gas introduction ports toward the circumference of the housing; and a second shunt portion provided between one of the plurality of first gas introduction ports and another first gas introduction port adjacent to the one first gas introduction port in the first supply path.

[0018] According to the laser processing machine of this aspect, it is possible to disperse the pressure and flow rate of the gas flowing in the first supply path as compared with the case where the first shunt portion and the second shunt portion are not provided.

[0019] (6) In the laser processing machine of the above aspect, it can be possible that the plurality of shunt portions further include a third shunt portion provided between the first shunt portion and the second shunt portion in the first supply path and at the boundary of the first supply path and the first blow-out portion.

[0020] According to the laser processing machine of this aspect, it is possible to homogenize the pressure and flow rate of the gas blown out from the first blow-out portion in the entire peripheral portion of the first end portion as compared with the case where the third shunt portion is not provided.

[0021] (7) In the laser processing machine of the above aspect, it can be possible that the first blow-out portion is inclined so as to blow out the gas toward a position at 50% or more and 80% or less of the distance from the second end portion to the first blow-out portion on the central axis of the housing.

[0022] According to the laser processing machine of this aspect, it is possible to suppress the generation of a local negative pressure in the internal space of the housing.

[0023] (8) In the laser processing machine of the above aspect, it can be possible that the first blow-out portion is inclined to blow out the gas toward a position at 70% of a distance on a central axis of the housing from the second end portion to the first end portion.

[0024] According to the laser processing machine of this aspect, it is possible to more reliably suppress the generation of the local negative pressure in the internal space of the housing.

[0025] (9) In the laser processing machine of the above aspect, it can be possible that the housing further includes a second blow-out portion provided on an entire circumference of the second end portion to blow out the gas from the second end portion toward a side opposite to the laser emission portion.

[0026] According to the laser processing machine of this aspect, it is possible to suppress or prevent the foreign matter from entering the internal space of the housing by the gas blown out from the second blow-out portion.

[0027] (10) In the laser processing machine of the above aspect, it can be possible that the housing further includes a second supply path provided on an entire circumference of the inside of the housing to supply the gas to the second blow-out portion.

[0028] According to the laser processing machine of this aspect, it is possible to provide the flow path for efficiently guiding the gas to the second blow-out portion by the housing.

[0029] (11) In the laser processing machine of the above aspect, it can be possible that the housing further includes a plurality of second gas introduction ports to introduce the gas to the second supply path.

[0030] According to the laser processing machine of this aspect, the gas is introduced from the plurality of positions with respect to the second supply path, and thus, it is possible to suppress the pressure deviation of the second supply path compared to a case where the gas is introduced to the second supply path from a single second gas introduction port.

[0031] (12) In the laser processing machine of the above aspect, it can be possible that the second supply path includes a fourth flow dividing portion provided in the vicinity of each of the plurality of second gas introduction ports in the second supply path to flow the gas introduced from the plurality of second gas introduction ports toward a circumferential direction of the housing, and a fifth flow dividing portion provided in the second supply path between one of the plurality of second gas introduction ports and another second gas introduction port adjacent to the one second gas introduction port.

[0032] According to the laser processing machine of this aspect, it is possible to stabilize the pressure and the flow rate of the gas flowing in the second supply path compared to a case where the fourth flow dividing portion and the fifth flow dividing portion are not provided.

[0033] (13) In the laser processing machine of the above-described aspect, it can be that the second blowout portion has an opening area smaller than an opening area of the first blowout portion.

[0034] According to the laser processing machine of this aspect, by making the airflow blown from the second blowout portion high pressure compared to the airflow blown from the first blowout portion, entry of foreign matter into the internal space of the housing can be suppressed.

[0035] (14) In the laser processing machine of the above-described aspect, it can be that the laser processing machine further includes an airflow generation portion provided so as to be separated from the housing and generate an airflow in a direction intersecting a central axis of the housing.

[0036] According to the laser processing machine of this aspect, foreign matter scattered from the workpiece can be washed away by the airflow of the first airflow generation portion, and entry of the foreign matter to the laser emission portion can be suppressed or prevented.

[0037] (15) In the laser processing machine of the above-described aspect, it can be that the airflow generation portion is provided so as to be separated from the housing by a distance of more than a length of the housing along the central axis.

[0038] According to the laser processing machine of this aspect, the airflow generated in the internal space of the housing can be suppressed from being disturbed by the airflow blown from the first airflow generation portion.

[0039] The present disclosure can also be implemented in various aspects other than the laser processing machine. For example, it can be implemented in aspects of a housing used in a laser processing machine, a manufacturing method of a laser processing machine, a manufacturing method of a housing, a laser processing method, an airflow generation method, and the like. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is an explanatory diagram showing a schematic configuration of a laser welding device of the present embodiment.

[0041] Figure 2 is an explanatory diagram showing an internal configuration of a housing.

[0042] Figure 3 is an explanatory diagram showing a flow path of a gas in the housing.

[0043] Figure 4 is a first explanatory diagram showing a result of fluid simulation using the laser welding device of the present embodiment.

[0044] Figure 5 is a second explanatory diagram showing a result of fluid simulation using the laser welding device of the present embodiment.

[0045] Figure 6 is a third explanatory diagram showing a result of fluid simulation using the laser welding device of the present embodiment.

[0046] Figure 7 is a cross-sectional view showing an internal structure of a housing as a comparative example.

[0047] Figure 8 is a first explanatory view showing a result of fluid simulation using a housing as a comparative example.

[0048] Figure 9 is a second explanatory view showing a result of fluid simulation using a housing as a comparative example.

[0049] Figure 10 is a third explanatory view showing a result of fluid simulation using a housing as a comparative example.

[0050] Figure 11 is an explanatory view showing an evaluation result of a focal position offset amount between a laser welding device as a comparative example and a laser welding device of the first embodiment. DETAILED DESCRIPTION

[0051] A. First Embodiment:

[0052] Figure 1 is an explanatory view showing a schematic structure of a laser welding device 100 of a laser processing machine as the present embodiment. The laser welding device 100 is, for example, a remote laser device used in a manufacturing process of a vehicle body of an automobile. The laser welding device 100 performs welding on a workpiece WK by, for example, irradiating the workpiece WK disposed on a stage ST with laser light. The workpiece WK is, for example, a plurality of steel sheets or the like that overlap each other. The laser welding device 100 is provided with a laser oscillator 30, a laser scanner 50, an air supply unit 60, a housing 70, a first airflow generating portion 62, and a second airflow generating portion 64.

[0053] The laser oscillator 30 generates laser light and guides it to the laser scanner 50 via an optical fiber cable or the like. The laser oscillator 30 is capable of generating laser light such as CO2 laser light, YAG laser light, fiber laser light, disc laser light, and excimer laser light.

[0054] The laser scanner 50 functions as a laser light emission portion that emits the laser light guided from the laser oscillator 30 via an emission port 58. The laser scanner 50 is also sometimes referred to as a scanner head. The laser scanner 50 is provided with a laser optical system and a protection glass 54. The laser optical system includes, for example, a mirror 52 such as a galvanometer and a lens group not shown. The lens group can include, for example, a collimator lens for making the laser light parallel light, a condenser lens for linking a focal point of the laser light with a processing point W0 on the workpiece WK, and the like. Note that, Figure 1 The optical path LZ of the laser light from the mirror 52 to the workpiece WK is schematically shown in FIG. 12.

[0055] The reflector 52 is configured, for example, to rotate about an axis. The laser welding apparatus 100 operates by rotating the reflector 52, enabling the laser to be applied even when the laser scanner 50 is fixed. Figure 1 The scan is performed within the predetermined range LR shown. In this disclosure, the distance from the reflector 52 to the machining point W0 on the workpiece WK is also referred to as the "focal length".

[0056] A protective glass 54 is disposed at the emission outlet 58 of the laser scanner 50. The protective glass 54 allows laser light from the optical system to pass through. The protective glass 54 prevents sputtering particles from the processing point W0 on the workpiece WK, as well as metal sublimation fumes contained in the workpiece WK, from colliding with the reflector 52 and the lens assembly during laser processing.

[0057] Foreign matter such as sputtering particles and fumes may sometimes adhere to the protective glass 54. When foreign matter adheres to the protective glass 54, the focal length of the laser may sometimes change due to the thermal lensing effect. The thermal lensing effect is a phenomenon caused by the thermal expansion of the protective glass 54 due to the absorption of laser light and the resulting heat from the foreign matter adhering to it, leading to a change in the refractive index of the protective glass 54. As a result, the laser welding apparatus 100 may sometimes be unable to properly focus the laser light onto the processing point W0 on the workpiece WK.

[0058] In this embodiment, the laser scanner 50 is connected to the robot 40. The robot 40 has a so-called multi-joint arm. The multi-joint arm is connected sequentially by multiple joints, including bending joints and torsional joints. The robot 40 is controlled by a robot control unit 20. The robot control unit 20 stores information such as the arm's rotation angle and movement amount for moving the laser scanner 50 to any position. The robot 40 adjusts the relative position of the laser scanner 50 with respect to the workpiece WK according to the control signals from the robot control unit 20. The robot 40 may have an arm with any mechanism containing one or more joints. However, the laser scanner 50 does not necessarily need to be connected to the robot 40. For example, the robot 40 may be omitted and the laser scanner 50 may be a fixed type.

[0059] The housing 70 is a generally cylindrical metal component mounted on the laser scanner 50. The housing 70 is installed near the emission outlet 58 of the laser scanner 50. The housing 70 is configured to cover the emission outlet 58 and the protective glass 54, suppressing or preventing foreign matter such as sputtering particles and fumes from adhering to the protective glass 54. The housing 70 is not limited to metal; it can also be made of resin or ceramic. The housing 70 is not limited to a cylindrical shape; it can also be a rectangular tube with a polygonal cross-section, or any cylindrical shape that allows the laser to pass through its internal space.

[0060] The inner wall of housing 70 defines the internal space of housing 70. The axis passing through the internal space of housing 70 is also referred to as the "central axis AX". The inner wall of housing 70 is configured to surround the optical path LZ of the laser emitted from the protective glass 54 and exiting the exit 58. In other words, housing 70 is mounted at the exit 58 of laser scanner 50 in a position where the laser emitted from laser scanner 50 can pass through the internal space of housing 70. In the following description, the direction along the central axis AX will be referred to as the "axial direction", and the direction along the outer edge of housing 70 in a plane perpendicular to the axial direction will be referred to as the "circumferential direction of housing 70". The end of housing 70 facing laser scanner 50 and protective glass 54 at both ends along the central axis AX will be referred to as the first end 70T, and the end opposite to the first end 70T will be referred to as the second end 70B. The second end 70B faces the workpiece WK during processing.

[0061] In this embodiment, a flow path for gas passage is provided in the housing 70 as described later. Gas supplied to the housing 70 is blown out from a predetermined position within the housing 70, thereby generating… Figure 1 The airflow AR1 is shown. Airflow AR1 is generated within the internal space of the housing 70 and within a predetermined range from the second end 70B toward the workpiece WK. When a negative pressure area exists within the internal space of the housing 70, it can become a major cause of the intake of foreign matter such as sputtering material and fumes. Therefore, in order to more effectively suppress the adhesion of foreign matter to the protective glass 54, it is preferable that the overall pressure of airflow AR1 is uniform. It should be noted that in Figure 1 In order to make the technology easier to understand, the airflow AR1, AR2, and AR3 are marked with shaded lines.

[0062] The first airflow generating unit 62 generates Figure 1 The high-speed, high-pressure airflow AR2 is shown. The first airflow generating unit 62 is sometimes also called an air knife. The first airflow generating unit 62 generates an airflow AR2 in a generally planar range in a direction intersecting the central axis AX of the housing 70. The airflow AR2 intersects the laser beam path LZ within the scanning laser range LR. As a result, sputtering material flying from the processing point W0 toward the laser scanner 50 during laser welding is swept away by the airflow generated from the first airflow generating unit 62. Consequently, it is possible to suppress or prevent sputtering material from reaching the laser scanner 50. In order to suppress the collision between foreign matter swept away by the airflow and the workpiece WK, the airflow AR2 preferably does not overlap with the workpiece WK.

[0063] In this embodiment, the first airflow generating unit 62 is as follows: Figure 1The second airflow generating portion 64 is disposed apart from the second end portion 70B as indicated by a distance L2. Thereby, the airflow AR1 generated in the inside space of the casing 70 is disturbed by the airflow AR2. In the present embodiment, the distance L2 from the second end portion 70B to the first airflow generating portion 62 is set to be equal to or more than the length LI of the casing 70 along the central axis AX. Note that the second airflow generating portion 64 is disposed at a position closer to the workpiece WK than the first airflow generating portion 62, and thus is disposed apart from the second end portion 70B in a state further apart than the first airflow generating portion 62.

[0064] The second airflow generating portion 64 generates a high-speed high-pressure airflow AR3 as indicated by an arrow. Figure 1 The second airflow generating portion 64 blows out an airflow AR3 in a substantially conical range with the second airflow generating portion 64 as an apex, and the airflow AR3 covers the entire workpiece WK. Thereby, the smoke generated from the workpiece WK at the time of laser welding is washed away by the airflow generated from the second airflow generating portion 64. As a result, it is possible to suppress or prevent the smoke from reaching the laser scanner 50. From the viewpoint of suppressing the airflows from interfering with each other and the function from deteriorating, the airflow AR2 and the airflow AR3 are preferably not overlapped with each other. The second airflow generating portion 64 is disposed at a position closer to the workpiece WK than the first airflow generating portion 62.

[0065] The air supply unit 60 can individually pressurize air to the first airflow generating portion 62, the second airflow generating portion 64, and the casing 70 using an air pump not shown. Note that the air supply unit 60 can also supply other gas such as nitrogen instead of air, for example.

[0066] The flow path formed in the casing 70 will be described using Figure 2 and Figure 3 . Figure 2 is a cross-sectional view illustrating the internal structure of the casing 70. The casing 70 has a first gas introduction port 74, a first supply path 722, and a first blowout portion 720. The first gas introduction port 74, the first supply path 722, and the first blowout portion 720. An airflow AR1 is generated in the inside space SP of the casing 70 by using air pressurized from the air supply unit 60.

[0067] The first gas introduction port 74 is connected to the air supply unit 60 as indicated in Figure 1 . The first gas introduction port 74 is disposed substantially perpendicular to the outer wall surface of the casing 70. The first gas introduction port 74 is connected to the first supply path 722 in the casing 70, and guides the air supplied from the air supply unit 60 to the first supply path 722.

[0068] In the present embodiment, the case 70 is provided with a plurality of first gas introduction ports 74. The plurality of first gas introduction ports 74 introduce air from a plurality of positions of the first supply path 722 to the inside of the first supply path 722. In the present embodiment, the plurality of first gas introduction ports 74 are provided at positions that are substantially equally spaced around the central axis AX on the outer wall surface of the case 70. Note that the first gas introduction ports 74 can be singular, and are not limited to four, but can be set to any number of two or more. Figure 2 In the present embodiment, only two first gas introduction ports 74 are illustrated, but in fact, four are provided. In the present embodiment, the four first gas introduction ports 74 are arranged in a manner that is substantially equally spaced around the central axis AX on the outer wall surface of the case 70. Note that the first gas introduction ports 74 can be singular, and are not limited to four, but can be set to any number of two or more.

[0069] The first supply path 722 guides the air supplied from the first gas introduction ports 74 to the first blow-out portion 720. The first supply path 722 is a belt-shaped space formed on the entire circumference in the inside of the case 70 along the circumferential direction. The "inside of the case 70" refers to the space between the inner wall surface of the case and the outer wall surface of the case 70. The first supply path 722 disperses the pressure of the air during the period in which the air supplied from the first gas introduction ports 74 is guided to the first blow-out portion 720. Thus, for example, compared to a case in which the first blow-out portion 720 and the first gas introduction ports 74 are directly connected, the pressure of the entire flow path of the first supply path 722 or the like can be made substantially uniform. The first supply path 722 can also be provided on the outer wall surface of the case 70, and is not limited to being in the inside of the case 70. In this case, the first supply path 722 can be formed, for example, by installing a pipe or the like on the outer wall surface of the case 70.

[0070] The first blow-out portion 720 blows out the air guided by the first supply path 722 from the entire circumference of the inside of the first end portion 70T toward the central axis AX of the case 70. An air current is generated in the internal space SP by the air blown out from the first blow-out portion 720. In the present embodiment, the first blow-out portion 720 is provided on the entire circumference of the inside of the first end portion 70T. The first blow-out portion 720 is a so-called slit-shaped opening. "The first blow-out portion 720 is provided at the first end portion 70T" includes a state in which the first blow-out portion 720 is provided in the vicinity of the first end portion 70T. "The first blow-out portion 720 is provided at the first end portion 70T" also includes a state in which the first blow-out portion 720 is provided separately from the first end portion 70T. A predetermined distance can be defined, for example, by a distance obtained by adding the thickness of the flow path of the first supply path 722 to the thickness of the case 70.

[0071] The air blown out from the first blow-out portion 720 generates an air current AR11 as shown in FIG. 1. The air current of the air current AR11 contributes to the generation of the air current AR1. Figure 2 Figure 1 ​The generation of the air current AR1 is shown. The first blowout portion 720 is not limited to one slit, but can be, for example, a plurality of slits. Also, the first blowout portion 720 can be any shape on the premise that it blows out air toward the inside space SP of the housing 70 at substantially equal pressure. For example, the first blowout portion 720 can be a plurality of openings instead of a slit shape. In this case, the plurality of openings can be arranged continuously on the entire peripheral portion of the first end portion 70T.

[0072] As shown, the first blowout portion 720 includes an upper surface 720A close to the upper surface of the protection glass 54 and a lower surface 720B opposite the upper surface 720A. The upper surface 720A can adjust the flow direction of the air blown out from the first blowout portion 720 by adjusting the inclination angle with respect to the central axis AX. In the present embodiment, the air flow direction in the upper surface 720A is inclined to a direction defined by a component in the direction toward the central axis AX and a component separating from the protection glass 54. Thereby, the air current AR11 is inclined in the direction from the first end portion 70T toward the second end portion 70B (the direction separating from the protection glass 54). Figure 2

[0073] The flow direction of the air blown out from the first blowout portion 720 is preferably a certain direction included in a range from a position PA at a distance of 80% of the height of the first blowout portion 720 to a position PB at a distance of 50% when the distance from the second end portion 70B to the upper surface 720A of the first blowout portion 720 on the central axis AX of the housing 70 (hereinafter also referred to as "the height of the first blowout portion 720") is set to 100%. The air blown out from the first blowout portion 720 can collide with each other on the central axis AX, and the collided air currents can flow toward the second end portion 70B. As a result, it is possible to suppress the generation of a local negative pressure in the inside space SP of the housing 70. For example, in a case where air is blown out from the second end portion 70B toward a position farther than the position PA, the air currents blown out from the first blowout portion 720 easily collide with each other in a state of not being inclined and in a state of high speed and high pressure. As a result, the air currents in the housing 70 can be likely to be turbulent. In a case where the air currents blown out from the first blowout portion 720 are blown out toward a position closer to the second end portion 70B than the position PB, it is difficult for them to collide with each other. As a result, a negative pressure is likely to be generated on the central axis AX. As a result, a foreign matter such as a sputter, smoke, or the like can be sucked toward the protection glass 54 by the negative pressure on the central axis AX. In the present embodiment, the flow direction of the air blown out from the first blowout portion 720 is set to a position PT at a distance of 70% of the height of the first blowout portion 720 based on the result of fluid simulation from the viewpoint of more reliably suppressing the generation of a negative pressure in the inside space SP.

[0074] ​The thickness of the air current AR11 can be adjusted by adjusting the inclination angle of the lower surface 720B of the first blow-out portion 720. In the present embodiment, the thickness of the air current AR11 is set to be relatively thick by inclining the lower surface 720B in the direction toward the second end portion 70B on the central axis AX. For example, the thickness of the air current AR11 is thicker than the thickness of the air current AR12 shown in FIG. 8. Note that the air current AR11 can also be set to be thin, for example, to the same thickness as the thickness of the air current AR12. Figure 2

[0075] In the present embodiment, the housing 70 further includes a partition wall 724, a second gas introduction port 76, and a second supply path 726. The second gas introduction port 76 and the second supply path 726 function as a flow path different from the first gas introduction port 74, the first supply path 722, and the first blow-out portion 720 by the partition wall 724. The second gas introduction port 76 and the second supply path 726 use the air pressurized by the air supply unit 60 to generate an air current from the second end portion 70B of the housing 70 to the outside of the housing 70.

[0076] The second gas introduction port 76 is connected to the air supply unit 60. The second gas introduction port 76 is disposed substantially perpendicular to the outer wall surface of the housing 70. The second gas introduction port 76 is connected to the second supply path 726 in the housing 70 and guides the air supplied from the air supply unit 60 to the second supply path 726.

[0077] In the present embodiment, the housing 70 includes a plurality of second gas introduction ports 76. The air is introduced from the plurality of second gas introduction ports 76 to one second supply path 726. Like the first gas introduction port 74, the four second gas introduction ports 76 are disposed at substantially equal intervals around the central axis AX on the outer wall surface of the housing 70. However, the number of the second gas introduction ports 76 can be different from that of the first gas introduction ports 74, and can be a single number or more than two.

[0078] The second supply path 726 guides the air supplied from the second gas introduction port 76 to the second blow-out portion 728. In the present embodiment, the second supply path 726 is a belt-shaped space formed on the entire circumference in the housing 70. However, the second supply path 726 can be provided on the outer wall surface of the housing 70.

[0079] ​The air guided by the second supply path 726 is blown out from the second blow-out portion 728 toward the side opposite to the laser scanner 50. In the present embodiment, the second blow-out portion 728 is one opening in the form of a so-called slit provided on the entire circumference of the inner side of the second end portion 70B. The "second blow-out portion 728 is provided at the second end portion 70B" also includes a state in which the second blow-out portion 728 is provided in the vicinity of the second end portion 70B, and the second blow-out portion 728 can be provided at a predetermined distance apart from the second end portion 70B. As the predetermined distance, for example, a distance obtained by adding the thickness of the flow path of the second supply path 726 to the thickness of the housing 70 or the like.

[0080] The air blown out from the second blow-out portion 728 generates Figure 2 the air current AR12 as shown. The air current AR12 contributes to the generation of the air current of the air current AR1 together with the air current AR11. The second blow-out portion 728 is not limited to one slit, and can be, for example, a plurality of slits, or can be a plurality of openings instead of the slit form.

[0081] As shown in Figure 2 , the second blow-out portion 728 includes a lower surface 728B reaching the second end portion 70B and an upper surface 728A opposite to the lower surface 728B. The upper surface 728A and the lower surface 728B are inclined to a direction defined by a direction component from the second end portion 70B toward the center axis AX and a direction component from the second end portion 70B toward the side opposite to the laser scanner 50. Thereby, the air current AR12 is inclined in a direction from the second end portion 70B toward the workpiece WK. However, it is not limited thereto, and the second blow-out portion 728 can be inclined to a direction defined by a direction component apart from the center axis AX and a direction component from the second end portion 70B toward the side opposite to the laser scanner 50.

[0082] In the present embodiment, as shown in Figure 2 , the opening area of the second blow-out portion 728 is set to be relatively small. The opening area of the second blow-out portion 728 is, for example, smaller than the opening area of the first blow-out portion 720. Therefore, the thickness of the generation range of the air current AR12 can be thinner than the thickness of the generation range of the air current AR11. As a result, the air current AR12 blown out from the second blow-out portion 728 can become higher in speed and pressure than the air current AR11 blown out from the first blow-out portion 720.

[0083] Figure 3 is an explanatory view showing the flow path of the gas inside the housing 70. In Figure 3 , for the convenience of explanation, the configuration of the first supply path 722 and the second supply path 726 inside the housing 70 is illustrated, and the illustration of the outer wall portion of the housing 70 is omitted. As shown in Figure 3As shown, in the present embodiment, the first supply path 722 and the second supply path 726 are two belt-shaped flow paths formed along the circumference of the housing 70, and are independently provided from each other by the partition wall 724.

[0084] As shown, in the first supply path 722, a plurality of shunt portions for shunting air introduced from the first gas introduction port 74 into the first supply path 722 are formed. Specifically, the first supply path 722 is provided with a first shunt portion 721, a second shunt portion 723, and a third shunt portion 725, which are different in function from each other. Figure 3

[0085] The first shunt portion 721 is provided in the vicinity of each of the four first gas introduction ports 74. The second shunt portion 723 is provided between one first gas introduction port 74A and another first gas introduction port 74B adjacent to the first gas introduction port 74A. In the present embodiment, the second shunt portion 723 is disposed midway between the first gas introduction ports 74. The first shunt portion 721 and the second shunt portion 723 have an elongated shape along the circumferential direction DR.

[0086] As indicated by an arrow F10, air supplied from the air supply unit 60 is introduced from the first gas introduction port 74A into the first supply path 722 and collides with the wall surface of the first supply path 722. The air introduced into the first supply path 722 is shunted by the first shunt portion 721 and the partition wall 724 and flows to both sides along the circumferential direction DR as indicated by an arrow F12. At this time, a part of the air flows toward between the first shunt portion 721 and the second shunt portion 723 as indicated by an arrow F11.

[0087] The air flowing along the direction F12 switches the flow direction to a direction F13 intersecting the direction F12 due to collision with air introduced from another first gas introduction port 74B. The air flowing along the direction F13 is shunted by the second shunt portion 723 and flows to both sides along the circumferential direction DR as indicated by an arrow F14. The air flowing along the direction F14 flows between the first shunt portion 721 and the second shunt portion 723 and toward the first blow-out portion 720.

[0088] The third shunt portion 725 is provided at a position between the first shunt portion 721 and the second shunt portion 723 on the first supply path 722 and at the boundary of the first supply path 722 and the first blow-out portion 720. The position of the third shunt portion 725 corresponds to a position at which the air flowing along the direction F11 and the air flowing along the direction F14 can collide with each other. In the present embodiment, two of the third shunt portions 725 are respectively provided for each of the positions as shown. Figure 3 However, the number of the third shunt portions 725 is not limited to two, and can be one or more than three. ​

[0089] In this embodiment, the third diverter 725 is approximately triangular in shape. Its base is located near the first outlet 720, and its apex is located at a position separating it from the first outlet 720. Preferably, the width of the third diverter 725 in the circumferential direction DR near the first outlet 720 is greater than the width at the position separating it from the first outlet 720. The third diverter 725 is not limited to an approximately triangular shape and can be any shape such as circular, elliptical, polygonal, or rectangular. Furthermore, the third diverter 725 can also be formed into a long strip shape along the axial direction DX.

[0090] Air flowing from between the first splitter 721 and the second splitter 723 towards the first outlet 720 is split into multiple directions corresponding to the number of third splitter 725, as indicated by direction F15. Air guided from the multiple split locations towards the first outlet 720 is blown out of the first outlet 720, as indicated by direction F16. Thus, air introduced into the first supply path 722 is split by the first splitter 721, the second splitter 723, and the third splitter 725, and guided towards the first outlet 720 while repeatedly colliding with each other. As a result, the air guided to the first outlet 720 is blown into the housing 70 from the first outlet 720 in a state where the pressure and flow rate are approximately uniform throughout the circumference of the first end 70T.

[0091] like Figure 3 As shown, the second supply path 726 includes multiple diversion sections for diverting air introduced from the second gas inlet 76 into the second supply path 726. Specifically, the second supply path 726 includes a fourth diversion section 727 and a fifth diversion section 729.

[0092] The fourth and fifth branch sections 727 and 729 are elongated along the circumferential direction DR and have the same function as the first and second branch sections 721 and 723 described above. The fourth branch section 727, like the first branch section 721, is located near each of the four second gas inlets 76. The fifth branch section 729, like the second branch section 723, is located between one second gas inlet 76A and another second gas inlet 76B adjacent to it.

[0093] As indicated by direction F20, the air supplied by the air supply unit 60 is introduced into the second supply path 726 through the second gas inlet 76A, colliding with the wall of the second supply path 726. The air introduced into the second supply path 726 is split by the fourth splitter 727 and the partition wall 724, flowing to both sides along the circumferential direction DR as indicated by direction F22. At this time, a portion of the air flows between the fourth splitter 727 and the fifth splitter 729 as indicated by direction F21.

[0094] The air flowing along the direction F22 is switched to a direction F23 intersecting the direction F22 by colliding with the air introduced from the adjacent second gas introduction port 76B. The air flowing along the direction F23 is divided by the fifth flow dividing portion 729, divided toward both sides along the circumferential direction DR as indicated by a direction F24, and flows between the fourth flow dividing portion 727 and the fifth flow dividing portion 729 toward the second blow-out portion 728. In this way, the air introduced to the second supply path 726 is divided by the fourth flow dividing portion 727 and the fifth flow dividing portion 729, guided to the second blow-out portion 728 while repeating collisions of the air with each other. As a result, the air guided to the second blow-out portion 728 is blown out from the second blow-out portion 728 to the outside of the casing 70 in a state where the pressure and the flow rate are substantially uniform over the entire circumference of the second end portion 70B as indicated by a direction F26.

[0095] Figure 4 is a first explanatory diagram illustrating a result of fluid simulation using the laser welding device 100 of the present embodiment. The "fluid simulation" is, for example, fluid analysis using numerical fluid dynamics (CFD: Computational Fluid Dynamics) using a computer. Figure 4 In, a simulation result in a cross-sectional view of the casing 70 in the laser welding device 100 is shown. In the simulation result, a distribution of the speed of the fluid (unit: m / s, for example) is shown in 20 levels according to the difference in color. For example, a portion where the flow rate is slow is shown in blue, a portion where the flow rate is relatively fast is shown in green, and a portion where the flow rate is fastest is shown in red. In Figure 4 In, for the sake of convenience of explanation, the portion where the flow rate is fastest and the portions from the fastest to the fifth level are illustrated by being surrounded with a solid line. Note that each simulation result in the present disclosure is a result obtained in a state where the second air flow generation portion 64 is disconnected. As Figure 4 indicated in, according to the simulation result, it can be understood that the region where the flow rate is fast substantially coincides with the shape of each of the air current AR11, the air current AR12, and the air current AR2.

[0096] Figure 5 is a second explanatory diagram illustrating a result of fluid simulation using the laser welding device 100 of the present embodiment. In Figure 5 In, a simulation result in a plan view of the casing 70 is shown. Specifically, a simulation result of the flow rate of the fluid when the position of the first blow-out portion 720 is observed along the central axis AX is shown. The method of indicating the flow rate in the simulation result is the same as that in Figure 4 , and thus the explanation is omitted. In Figure 5 In, the same as in Figure 4Also, for the sake of convenience of explanation, the portion where the flow rate is fastest and the portions from the fastest to the fifth fastest are illustrated by being surrounded with a solid line.

[0097] As Figure 5 indicated, the region where the flow rate is fast is generated by the air current flowing in the direction F16 blown from the first blow-out portion 720 toward the internal space SP of the housing 70. According to the simulation result, it is known that the region where the flow rate is fast is approximately uniform in size on the entire peripheral portion of the internal space SP, and the air current AR11 blows the air current from the first blow-out portion 720 toward the internal space SP at approximately uniform pressure and flow rate.

[0098] According to Figure 4 and Figure 5 the simulation result shown in, the following can be understood.

[0099] (1) As Figure 4 indicated, the internal space SP of the housing 70 is covered with the air current AR12 where the flow rate is fast. Thereby, it is possible to suppress or prevent foreign matter such as sputter, smoke, and the like from entering the internal space SP of the housing 70.

[0100] (2) As Figure 4 and Figure 5 indicated, the entire protection glass 54 is covered with the air current AR11 at approximately uniform pressure and flow rate within the internal space SP of the housing 70. Thereby, even in a case where foreign matter such as sputter, smoke, and the like enters the internal space SP of the housing 70, it is possible to suppress or prevent collision with the protection glass 54.

[0101] (3) As Figure 4 indicated, the air current AR11 and the air current AR12 have approximately line-symmetrical shapes with respect to the center axis AX, and a stable air current where the distribution of the flow rate is uniform is generated.

[0102] (4) It is possible to suppress the air current AR2 blown from the first air current generation portion 62 from disturbing the air current in the vicinity of the housing 70 in the air current AR11 and the air current AR12.

[0103] Figure 6 is a third explanatory diagram showing a result of fluid simulation using the laser welding device 100 of the present embodiment. Figure 6 The simulation result of the housing 70 in the laser welding device 100 in cross section is shown in. In the simulation result, the distribution of pressure (unit: for example, “Pa”) is shown in 20 levels according to the difference in color. For example, the portion where the pressure is equal to the atmospheric pressure is shown in green, the portion where the pressure is higher than the atmospheric pressure, that is, the portion of positive pressure is shown in red, and the portion of negative pressure is shown in blue. In Figure 6In the simulation result shown, the entire region of the inside space SP of the case 70 and the vicinity of the case 70 shows green, and there are almost no regions of positive pressure and negative pressure. It can be confirmed that the air pressure is stable at the inside space SP of the case 70 and the vicinity thereof.

[0104] The results of the fluid simulation of the case 200 as a comparative example will be described using Figures 7-10 Figure 7 is a cross-sectional view illustrating the internal structure of the case 200 as a comparative example. The case 200 differs from the case 70 of the laser welding apparatus 100 of the present embodiment in the structure of the blow-off portion, and is the same as the case 70 in other structures.

[0105] The case 200 includes a first supply path 222, a plurality of first blow-off portions 220, a partition wall 224, a second supply path 226, a second blow-off portion 228, and a plurality of third blow-off portions 223. The first supply path 222 and the second supply path 226 are belt-shaped spaces formed in the inside of the case 200 along the circumferential direction, and air from the air supply unit 60 is introduced thereto. The first supply path 222 and the second supply path 226 are separated from each other by the partition wall 224. Four first gas introduction ports 230, which are configured similarly to the first gas introduction port 74, are connected to the first supply path 222. Four second gas introduction ports, which are configured similarly to the second gas introduction port 76, are connected to the second supply path 226. Note that no flow dividing portion is formed in the first supply path 222 and the second supply path 226.

[0106] The first blow-off portion 220 communicates with the first supply path 222, and blows out the air supplied to the first supply path 222 toward the inside space of the case 200. The first blow-off portion 220 is disposed at a position separated from the first end portion 200T, unlike the first blow-off portion 720. Further, the upper surface and the lower surface that constitute the first blow-off portion 220 are not inclined. The third blow-off portion 223 communicates with the second supply path 226, and blows out the air supplied to the second supply path 226 toward the inside space. The upper surface and the lower surface that are prescribed for the first blow-off portion 220 and the third blow-off portion 223 are not inclined. The first blow-off portion 220 and the third blow-off portion 223 each have an elongated shape along the circumferential direction. The second blow-off portion 228 is provided on the entire peripheral portion of the second end portion 200B. The second blow-off portion 228 is a so-called slit-shaped opening. The second blow-off portion 228 blows out gas from the second end portion 200B toward the outside of the case 200.

[0107] Figure 8 is a view illustrating the results of the fluid simulation using the case 200 as a comparative example. In Figure 8 is shown in the view along the central axis AX2 Figure 7 ​the simulation results of the flow rate of the fluid in the case of the VIII-VIII position. The representation method of the flow rate in the simulation results is the same as that in Figure 4 , and thus the explanation is omitted. In Figure 8 , as in Figure 4 , for the convenience of explanation, the site of the fastest flow rate and the sites from the fastest to the fifth fastest are illustrated by being surrounded with solid lines. Figure 8 As shown in

[0108] As shown in Figure 8 , the air introduced from the first gas introduction port 230A collides with the wall surface of the first supply path 222, and flows along the wall surface of the first supply path 222, for example, toward the direction F120. At this time, the air flowing in the direction F120 reaches the first blow-out portion 220A in the vicinity of the first gas introduction port 230A, but is not ejected from the first blow-out portion 220A, and continues to flow in the direction F120. The air flowing in the direction F120 collides with the air introduced from the adjacent other first gas introduction port 230B and passing through the first blow-out portion 220B in the vicinity of the first blow-out portion 220T at a position in the middle of the first gas introduction ports 230A and 230B. As a result, the flow direction of the air is switched to the direction F130, and the air becomes the air current SR1 blown out from the first blow-out portion 220T. Note that the same simulation results are shown in the second supply path 226 and the third blow-out portion 223.

[0109] Figure 9 is a second explanatory diagram showing the fluid simulation results using the case 200 as a comparative example. Figure 9 In Figure 4 , the representation method of the flow rate in the simulation results is the same as that in Figure 9 , and thus the explanation is omitted. In , for the convenience of explanation, the site of the fastest flow rate and the sites from the fastest to the fifth fastest are illustrated by being surrounded with solid lines.

[0110] According to the simulation results shown in Figure 9 , the following can be understood.

[0111] (1) The air current SR1 blown out from the first blow-out portion 220 and the air current SR2 blown out from the third blow-out portion 223 are generated. The air current SR1 and the air current SR2 do not cover the protective glass 54.

[0112] (2) The flow rate of the air current SR3 blown out from the second blow-out portion 228 is slower than those of the air current SR1 and the air current SR2.

[0113] Figure 10is a third explanatory diagram showing a result of fluid simulation using the case 200 as a comparative example. Figure 10 A pressure distribution in a cross section of the case 200 is shown in Figure 6 . The method of representing the pressure distribution in the simulation result is the same as that in . Therefore, the explanation is omitted.

[0114] As shown in Figure 10 , according to the simulation result, it is confirmed that there are a range PP1, PP2 showing a positive pressure and a range PN1, PN2 showing a negative pressure in the internal space of the case 200. The positive pressure of the range PP1 is generated by the air flows SR1, SR2 blown from the first blow-out portion 220 and the third blow-out portion 223. The positive pressure of the range PP2 and the negative pressure of the ranges PN1, PN2 are presumed to be generated due to the air flows SR1, SR2 generated non-uniformly in the internal space of the case 200 as represented in Figure 8 . As shown in the ranges PN1, PN2 shown in Figure 10 , the negative pressure generated in the internal space of the case 200 can be a main cause of sucking in foreign matters such as sputter, smoke and the like and colliding the foreign matters to the protective glass 54. Also, as represented in Figure 9 , the flow rate of the air flow SR3 is slow, so it is difficult to suppress or prevent the foreign matters from entering the internal space of the case 200.

[0115] Figure 11 is an explanatory diagram showing evaluation results of the amount of shift of the focal point position between the laser welding device provided with the case 200 as a comparative example and the laser welding device 100 of the present embodiment. In Figure 11 , the vertical axis represents the amount of shift of the focal point position (unit: mm) and the horizontal axis represents the number of days of operation of the laser welding device. Figure 11 The graph GR shown in shows the evaluation results of the laser welding device provided with the case 200 as a comparative example and the graph Gl shows the evaluation results of the laser welding device 100 of the present embodiment. The shift of the focal length can be generated due to the thermal lens effect as described above. That is, the more the amount of attachment of the foreign matters to the protective glass 54, the greater the amount of shift of the focal length can be.

[0116] The amount of shift of the focal point position can be derived, for example, by measuring the intensity of the reflected light of the laser from the workpiece WK. Specifically, the laser is irradiated to the workpiece WK at the focal length determined in advance as the start position of the measurement and the intensity of the reflected light is measured. Then, while moving the focal length at a predetermined interval, the intensity of the reflected light from the workpiece WK is measured. The position at which the intensity of the reflected light becomes a peak value indicates the current focal length. Therefore, the amount of shift of the focal point position can be calculated by finding the difference of the amount of shift between the detected focal length at which the peak intensity is obtained and the reference position determined in advance.

[0117] Figure 11The threshold value TR shown is an allowable upper limit value of the focal position shift amount required in the laser welding device 100. When the focal position shift amount becomes the threshold value TR or more, replacement of the protective glass 54 is required. As indicated by the graph GR, in the housing 200 of the comparative example, the slope of the increase in the focal position shift amount with respect to the number of days of operation is large. This means that the speed of attachment of foreign matter to the protective glass 54 is fast. In the housing 200, the focal position shift amount exceeds the threshold value TR at the time when the number of days of operation reaches 4 days. In contrast, in the laser welding device 100 of the present embodiment, as indicated by the graph Gl, the focal shift amount exceeds the threshold value TR at the time when the number of days of operation reaches 10 days. That is, according to the laser welding device 100 of the present embodiment, the speed of attachment of foreign matter such as sputter, smoke, and the like to the protective glass 54 can be reduced compared to the case where the housing 200 of the comparative example is provided. Figure 11 As shown by the experimental results, the laser welding device 100 of the present embodiment can reduce the speed of attachment of foreign matter such as sputter, smoke, and the like to the protective glass 54 compared to the case where the housing 200 of the comparative example is provided. Specifically, it is known that the replacement frequency of the protective glass 54 can be reduced to one fifth.

[0118] As described above, according to the laser welding device 100 of the present embodiment, the housing 70 is provided with the first blowout portion 720 provided on the entire circumference of the inner side of the first end portion 70T for blowing air toward the central axis AX of the housing 70. Air is blown from the entire circumference of the inner side of the first end portion 70T toward the internal space SP of the housing 70 via the first blowout portion 720. Therefore, an air current that covers the protective glass 54 can be generated in the internal space SP of the housing 70, and even in the case where foreign matter such as sputter, smoke, and the like enters the internal space SP of the housing 70, collision with the protective glass 54 can be suppressed or prevented. An air current with a substantially uniform flow rate can be generated on the entire peripheral portion of the internal space SP. As a result, the air pressure in the internal space SP of the housing 70 can be stabilized, and the introduction of foreign matter into the internal space SP can be suppressed or prevented.

[0119] According to the laser welding device 100 of the present embodiment, the first supply path 722 is provided on the entire circumference of the inside of the housing 70 for supplying air to the first blowout portion 720. Therefore, a flow path for efficiently guiding air to the first blowout portion 720 can be provided using the housing 70.

[0120] According to the laser welding device 100 of the present embodiment, the housing 70 further includes four first gas introduction ports 74 for introducing air from a plurality of positions in the housing 70 to the first supply path 722. By introducing air from a plurality of positions with respect to the first supply path 722, compared to the case where air is introduced to the first supply path 722 from a single first gas introduction port 74, the pressure deviation of the first supply path 722 can be suppressed.

[0121] According to the laser welding device 100 of the present embodiment, the first supply path 722 has a plurality of shunt portions for shunting air. Thus, compared to a case where a groove-shaped flow path or a pipe is provided inside the housing 70, air can be guided in a desired direction by a simple configuration.

[0122] According to the laser welding device 100 of the present embodiment, the first supply path 722 is provided with a first shunt portion 721 disposed in the vicinity of each of the plurality of first gas introduction ports 74 and a second shunt portion 723 disposed between one first gas introduction port 74A and another first gas introduction port 74B adjacent to the first gas introduction port 74A among the plurality of first gas introduction ports 74. The first shunt portion 721 causes the gas introduced from the plurality of first gas introduction ports 74 to flow toward the circumferential direction DR of the housing 70. Thus, air introduced into the first supply path 722 from the first gas introduction ports 74 can be caused to flow toward the circumferential direction DR. The air flowing toward the circumferential direction DR can cause air introduced from the adjacent first gas introduction ports 74A, 74B to collide with each other and can be diffused by the second shunt portion 723. Thus, according to the laser welding device 100 of the present embodiment, compared to a case where, for example, the first shunt portion 721 and the second shunt portion 723 are not provided, by dispersing air flowing in the first supply path 722, the pressure and the flow rate of the air flowing in the first supply path 722 can be uniformized.

[0123] According to the laser welding device 100 of the present embodiment, the first supply path 722 further has a third shunt portion 725 disposed at a boundary between the first shunt portion 721 and the second shunt portion 723 and between the first supply path 722 and the first blowout portion 720. Air that has collided with each other and diffused by the second shunt portion 723 can be further dispersed and fed to the first blowout portion 720. Thus, compared to a case where the third shunt portion 725 is not provided, the pressure and the flow rate of the air blown out from the first blowout portion 720 can be uniformized over the entire peripheral portion of the first end portion 70T.

[0124] According to the laser welding device 100 of the present embodiment, the first blowout portion 720 is inclined so as to blow out gas at a position that is more than 50% and less than 80% of a distance from the second end portion 70B to the first blowout portion 720 on the central axis AX of the housing 70. Thus, the airflows blown out from the first blowout portion 720 can collide with each other in an inclined state on the central axis AX and the airflows after the collision can flow toward the second end portion 70B. Thus, it is possible to suppress the generation of a local negative pressure in the internal space SP of the housing 70.

[0125] According to the laser welding device 100 of the present embodiment, the first blowout portion 720 is inclined so as to blow gas at a position PT that is 70% of the distance from the second end portion 70B to the first blowout portion 720 on the central axis AX of the housing 70. Thus, it is possible to more reliably suppress the generation of a local negative pressure within the internal space SP of the housing 70.

[0126] According to the laser welding device 100 of the present embodiment, the housing 70 further includes a second blowout portion 728 provided on the entire circumference of the second end portion 70B for blowing gas toward a direction F10 defined by a component of the direction from the second end portion 70B toward the central axis AX and a component of the direction from the second end portion 70B toward the side opposite to the laser scanner 50. The air blown from the second blowout portion 728 can cover the internal space SP of the housing 70, and can suppress or prevent foreign matter such as sputter, smoke, or the like from entering the internal space SP of the housing 70. Also, it is possible to generate an air current of substantially uniform flow rate from the entire circumference of the second end portion 70B. As a result, it is possible to stabilize the air pressure in the vicinity of the internal space SP of the housing 70, and to suppress the air current of the internal space SP of the housing 70 from being disturbed.

[0127] According to the laser welding device 100 of the present embodiment, the housing 70 further includes a second supply path 726 provided on the entire circumference of the inside of the housing 70 for supplying air to the second blowout portion 728. Thus, it is possible to provide a flow path for efficiently guiding air to the second blowout portion 728 using the housing 70.

[0128] According to the laser welding device 100 of the present embodiment, the housing 70 further includes four second gas introduction ports 76 for introducing gas from a plurality of positions in the housing 70 to the second supply path 726. By introducing air from a plurality of positions with respect to the second supply path 726, it is possible to suppress the pressure deviation of the second supply path 726 compared to the case where air is introduced to the second supply path 726 from a single second gas introduction port.

[0129] According to the laser welding device 100 of the present embodiment, the second supply path 726 is provided with a fourth flow dividing portion 727 and a fifth flow dividing portion 729. The fourth flow dividing portion 727 is provided in the vicinity of each of the plurality of second gas introduction ports 76, and is configured to cause the gas introduced from the plurality of second gas introduction ports 76 to flow toward the circumferential direction DR of the housing 70. The fifth flow dividing portion 729 is provided between one second gas introduction port 76A and another second gas introduction port 76B adjacent to the second gas introduction port 76A among the plurality of second gas introduction ports 76. By the fourth flow dividing portion 727, the air introduced from the second gas introduction port 76 to the second supply path 726 can be caused to flow toward the circumferential direction DR. Also, the air flowing toward the circumferential direction DR can collide with each other and be diffused by the fifth flow dividing portion 729. Thus, according to the laser welding device 100 of the present embodiment, compared to a case where the fourth flow dividing portion 727 and the fifth flow dividing portion 729 are not provided, the pressure and the flow rate of the air flowing in the second supply path 726 can be stabilized.

[0130] According to the laser welding device 100 of the present embodiment, the opening area of the second blowout portion 728 is smaller than the opening area of the first blowout portion 720. By causing the air current blown out from the second blowout portion 728 to be high-speed and high-pressure compared to the air current blown out from the first blowout portion 720, the inside space SP of the housing 70 can be covered with the air current of the high-speed and high-pressure air current AR12. Thus, the entry of foreign matter such as sputter, smoke, or the like into the inside space SP of the housing 70 can be more reliably suppressed or prevented.

[0131] According to the laser welding device 100 of the present embodiment, the first air current generating portion 62 is provided so as to be separated from the second end portion 70B of the housing 70, and is configured to generate an air current in a direction intersecting the optical path LZ of the laser. The sputter scattered from the machining point W0 of the workpiece WK can be washed away by the air current from the first air current generating portion 62, and the sputter can be suppressed or prevented from reaching the laser scanner 50.

[0132] According to the laser welding device 100 of the present embodiment, the first air current generating portion 62 is provided so as to be separated from the second end portion 70B of the housing 70 by a distance L2 that is longer than the length L1 of the housing 70 along the central axis AX. Thus, the air current generated in the inside space SP of the housing 70 can be suppressed from being disturbed by the air current blown out from the first air current generating portion 62.

[0133] B. Other Embodiments

[0134] (B1) In the above-described embodiments, the laser welding device 100 was described as an example of a laser processing machine. In this regard, the laser processing machine is not limited to the laser welding device 100, and can be a laser processing machine for various uses such as laser cutting, laser marking, and the like.

[0135] (B2) In the above-described embodiment, an example in which the housing 70 and the laser scanner 50 are separate is shown. In contrast, the housing 70 and the laser scanner 50 may, for example, also be integrally formed as one housing. In this case, for example, it is possible to make the boundary of the protective glass 54 and the internal space SP of the housing 70 the first end portion 70T of the housing 70.

[0136] (B3) In the above-described embodiment, an example in which the housing 70 is provided with the first gas introduction port 74, the first supply path 722, and the first blowout portion 720 and is provided with the second gas introduction port 76, the second supply path 726, and the second blowout portion 728 is shown. In contrast, for example, in a case in which the attachment of foreign matter to the protective glass 54 can be sufficiently suppressed by the first gas introduction port 74, the first supply path 722, and the first blowout portion 720, it is also possible to omit the second gas introduction port 76, the second supply path 726, and the second blowout portion 728.

[0137] (B4) In the above-described first embodiment, an example in which a plurality of branch portions are formed in the first supply path 722 and the second supply path 726 is shown. In contrast, the first supply path 722 and the second supply path 726 can also not be provided with branch portions. Also, the first supply path 722 and the second supply path 726 can also be formed in a groove shape along the flow path of the air described above. According to the laser welding device 100 thus configured, it is easy to guide the gas supplied to the first supply path 722 and the second supply path 726 to a desired position of the first blowout portion 720.

[0138] The present disclosure is not limited to the above-described embodiments, and can be implemented with a variety of structures within a range not departing from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each of the modes recited in the summary of the invention can be appropriately replaced or combined in order to solve part or all of the above-described problems or in order to achieve part or all of the above-described effects. Also, if the technical features are not described as essential contents in the present specification, they can be appropriately deleted.

[0139] Explanation of Reference Signs

[0140] 20 … robot 30 … robot control section 40 … laser oscillator 50 … robot 52 … mirror 54 … protective glass 58 … emission port 60 … air supply unit 62 … first airflow generation section 64 … second airflow generation section 70 … housing 70B … second open end portion 70T … first open end portion 74, 74A, 74B … first gas introduction port 76, 76A, 76B … second gas introduction port 100 … laser welding device 200 … housing 200B … second open end portion 200T … first open end portion 220, 220A, 220B, 220T … first blowoff section 222 … first supply passage 223 … third blowoff section 224 … partition wall 226 … second supply passage 228 … second blowoff section 230, 230A, 230B … first gas introduction port 720 … first blowoff section 720A … upper surface 720B … lower surface 721 … first flow divider 722 … first supply passage 723 … second flow divider 724 … partition wall 725 … third flow divider 726 … second supply passage 727 … fourth flow divider 728 … second blowoff section 728A … upper surface 728B … lower surface 729 … fifth flow divider AR1, AR11, AR12, AR2, AR3 … airflow AX, AX2 … central axis DR … circumferential direction DX … axial direction LZ … optical path SP … internal space SR1-SR3 … airflow ST … object table W0 … processing point WK … workpiece

Claims

1. A laser processing machine, comprising: A laser emission system for emitting a laser beam, the laser emission system having a protective glass through which the laser beam can pass; and The housing is installed in the laser emission system. The housing is cylindrical and configured to surround the optical path of the laser emitted from the laser emission system. The housing includes: The first end faces the protective glass; The second end is located on the opposite side to the first end; and The first blowing section has a slit-like opening and is arranged along the entire circumference of the inner side of the first end. The first blowing section blows gas toward the central axis of the housing. The first blowing section includes an upper surface near the protective glass and a lower surface opposite the upper surface. The upper surface adjusts the flow direction of the gas blown out from the first blowing section by adjusting its tilt angle relative to the central axis. The airflow direction on the upper surface is inclined in a direction defined by the directional component toward the central axis and the directional component separating from the protective glass, so that the airflow is inclined in a direction from the first end toward the second end. When the distance from the second end to the upper surface of the first blowing part on the central axis, i.e., the height of the first blowing part, is set to 100%, the flow direction of the gas blown out from the first blowing part is a certain direction included in the range from a position that is a distance of 80% of the height of the first blowing part to a position that is a distance of 50% of the height of the first blowing part. The thickness of the airflow is adjusted by adjusting the tilt angle of the lower surface of the first blow-out section.

2. The laser processing machine according to claim 1, wherein, The housing also includes a first supply path arranged around the entire circumference of the interior of the housing. The first supply path supplies gas to the first blow-out section.

3. The laser processing machine according to claim 2, wherein, The housing also includes a plurality of first gas inlets for introducing gas into the first supply path.

4. The laser processing machine according to claim 3, wherein, The first supply path has multiple diversion sections for diverting the gas.

5. The laser processing machine according to claim 4, wherein, The plurality of diversion sections include a first diversion section and a second diversion section. The first diversion section is disposed near each of the plurality of first gas inlets in the first supply path, and the first diversion section is configured to allow gas to flow circumferentially toward the housing, the gas being introduced from the plurality of first gas inlets. The second diversion section is disposed between one of the plurality of first gas inlets and another first gas inlet adjacent to the first gas inlet.

6. The laser processing machine according to claim 5, wherein, The plurality of flow dividers also includes a third flow divider. The third branch section is located between the first branch section and the second branch section in the first supply path.

7. The laser processing machine according to any one of claims 1 to 6, wherein, The first blowing part is configured to blow gas toward a position on the central axis of the housing, the position being within the range of 50% to 80% of the distance from the second end to the first blowing part.

8. The laser processing machine according to claim 7, wherein, The specified position is the position at 70% of the distance from the second end to the first blowing part.

9. The laser processing machine according to any one of claims 1 to 6, wherein, The housing also includes a second blow-out section. The second blowing part is arranged around the entire circumference of the second end, and the second blowing part blows gas from the second end toward the side opposite to the laser emission system.

10. The laser processing machine according to claim 9, wherein, The housing also includes a second supply passage disposed along the entire circumference of the interior of the housing. The second supply path supplies gas to the second blow-out section.

11. The laser processing machine according to claim 10, wherein, The housing also includes a plurality of second gas inlets for introducing gas into the second supply path.

12. The laser processing machine according to claim 11, wherein, The second supply path includes a fourth branch section and a fifth branch section. The fourth diversion section is disposed near each of the plurality of second gas inlets in the second supply path, and the fourth diversion section is configured to allow gas to flow circumferentially toward the housing, the gas being introduced from the plurality of second gas inlets. The fifth diversion section is disposed between one of the plurality of second gas inlets and another second gas inlet adjacent to the first second gas inlet.

13. The laser processing machine according to claim 9, wherein, The opening area of ​​the second blowing part is smaller than the opening area of ​​the first blowing part.

14. The laser processing machine according to any one of claims 1 to 6, wherein, The laser processing machine also includes an airflow generating unit located at a position separated from the housing. The airflow generating section generates airflow in a direction that intersects the central axis of the housing.

15. The laser processing machine according to claim 14, wherein, The airflow generating unit is positioned at a distance greater than or equal to the length along the central axis of the housing, separated from the housing.

Images