Laser beam machining torch

Abstract

To provide a laser beam machining torch capable of reducing chances of damaging and alteration of a protective plate provided in the laser beam machining torch.SOLUTION: Different from conventional one, this laser beam machining torch comprises: a torch body; a nozzle; a protective plate; a protective plate fixing structure for fixing the protective plate to the torch body so as to be held between a laser optical system and the nozzle; and a shield gas supply device. The protective plate fixing structure includes an introduction surface facing the surface of the protective plate. A shield gas passes from the inside of the torch body through an introduction passage having, as a section, a space held between the surface of the protective plate and the introduction surface to jet out, and flows along the surface of the protective plate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a laser processing torch, and more particularly to a laser processing torch for processing a workpiece with a laser. [Background technology]

[0002] A laser processing robot may be used for laser processing a work piece. For example, it is used by a laser processing robot to irradiate metal with laser light for welding. For example, a laser processing torch is fixed to the end effector of an articulated robot, and the laser processing robot is used to irradiate laser light according to a previously taught trajectory.

[0003] In laser welding, a torch that emits laser light is used as a laser processing torch. The torch is composed of a torch body and a nozzle. For example, a laser optical system is composed of a collimator lens and a condenser lens. For example, a laser optical system is composed of a collimator lens, a condenser lens, and a reflecting lens. A laser beam is generated by a laser oscillator and guided to the torch by an optical fiber. An operator or a robot performs the laser processing operation while keeping the focal point of the laser light focused by the focusing lens at an appropriate position near the portion to be processed of the workpiece.

[0004] An operator or a robot operates the laser processing torch to irradiate the workpiece with laser light. The portion of the workpiece is laser machined along the trajectory.

[0005] When performing laser welding, an operator or robot holds a laser processing torch so that the opening at the tip of the nozzle is directed toward the part of the workpiece to be processed, and while spraying shielding gas from the tip of the nozzle, irradiates the workpiece with laser light through the opening at the tip of the nozzle. When the laser light is irradiated onto the portion to be processed of the workpiece, the portion to be processed is melted by the energy of the laser light and then solidified, thereby completing the processing. When a laser beam is irradiated onto a portion of a workpiece to be processed, particles of the molten workpiece may fly off from the molten portion. The molten particles of the workpiece are called spatters. In rare cases, spatter may enter the interior of the laser processing torch through the opening at the tip of the nozzle. To prevent sputter from damaging the laser optical system, a protective plate is provided at the joint between the torch body and the nozzle. For example, the protective plate is made of quartz glass.

[0006] If the sputter enters the interior of the laser processing torch through the nozzle opening and adheres to the protective plate, the protective plate can be damaged or altered by the heat of the sputter, reducing the transmittance of the laser light. Many ideas have been proposed in the past to prevent this phenomenon. Even when using a laser processing torch incorporating this idea, if the speed at which the sputter scatters is high, it may not be possible to prevent damage and deterioration of the protective plate. Since the protective plate must be replaced every time it becomes damaged or deteriorated, the throughput of the laser processing work decreases.

[0007] As described above, further ideas for reducing the chances of damage or deterioration of the protective plate provided on the laser processing torch and improving the throughput of the laser processing have been desired. Summary of the Invention [Problem to be solved by the invention]

[0008] In view of the above demand, the present invention aims to provide a laser processing torch that can reduce the chance of damage or deterioration of a protective plate provided on the laser processing torch. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a laser processing torch for processing a workpiece with a laser, comprising: a torch body that incorporates a laser optical system and guides a laser beam emitted from the laser optical system along a central axis of the laser; a nozzle having an opening for emitting a laser beam, the nozzle being detachably fixed to the torch body; a protective plate that is a plate-like member that is made of a material that is transparent to laser light and is surrounded by a pair of front and side surfaces and is installed inside the torch body; a shielding gas supply device for supplying a shielding gas to a side of the torch body where the laser optical system is located, the side being separated by the protective plate; a protective plate fixing structure that fixes the protective plate to the torch body at a position sandwiched between the laser optical system and the nozzle, with a virtual axis that is a virtual axis perpendicular to a surface of the protective plate aligned with a laser central axis; Equipped with the protective plate fixing structure has one or more guide surfaces that face a surface of the protective plate facing the nozzle; The shielding gas supplied by the shielding gas supply equipment is guided from the inside of the torch body to one or more guide passages, which are passages having as their cross section a gap sandwiched between the surface of the protective plate facing the nozzle and the one or more guide surfaces facing said surface, and is sprayed into the inside of the nozzle so as to flow along the surface of the protective plate facing the nozzle toward the side of the laser center axis.

[0010] In the above-described configuration of the present invention, the torch body incorporates a laser optical system and guides the laser light emitted from the laser optical system along the laser central axis. The nozzle is detachably fixed to the torch body and has an opening through which a laser beam is emitted. The protective plate is a plate-like member made of a material that is transparent to laser light and surrounded by a pair of front and side surfaces, and is disposed inside the torch body. The shielding gas supply device supplies shielding gas to the side of the torch body where the laser optical system is located, with the protective plate as a boundary. The protective plate fixing structure is a structure in which the protective plate is fixed to the torch body at a position sandwiched between the laser optical system and the nozzle, with a virtual axis that is perpendicular to the surface of the protective plate aligned with the laser central axis. The protective plate fixing structure has one or more guide surfaces which face the surface of the protective plate facing the nozzle. The shielding gas supplied by the shielding gas supply equipment is guided from the inside of the torch body to one or more guide passages, which are passages having a cross-section defined by a gap between the surface of the protective plate facing the nozzle and the one or more guide surfaces facing that surface, and is sprayed into the inside of the nozzle so as to flow along the surface of the protective plate facing the nozzle toward the laser center axis. As a result, when sputtering occurs during laser processing, the sputtering is blocked by the shielding gas flowing along the surface of the protective plate facing the nozzle toward the laser central axis, thereby preventing the sputtering from adhering to the protective plate.

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention includes any one of the following embodiments or a combination of two or more of the following embodiments.

[0012] In the laser processing torch according to an embodiment of the present invention, the protective plate fixing structure has a plurality of guide grooves, which are grooves having a bottom surface facing the surface of the protective plate facing the nozzle, The shielding gas supplied by the shielding gas supply equipment is guided from the inside of the torch body to a plurality of guide passages, which are passages having a cross-section that is a gap surrounded by the surface of the protective plate facing the nozzle and the plurality of guide grooves having the surface facing the nozzle as their bottom surface, and is sprayed into the inside of the nozzle so as to flow along the surface of the protective plate facing the nozzle toward the laser center axis. In the configuration of the above embodiment, the protective plate fixing structure has a plurality of guide grooves, which are grooves having, as their bottom surfaces, surfaces facing the surface of the protective plate facing the nozzle side. The shielding gas supplied by the shielding gas supply equipment is guided from the inside of the torch body to a plurality of guide passages, which are passages having a cross-section that is a gap surrounded by the surface of the protective plate facing the nozzle and the plurality of guide grooves having the surface facing the nozzle as their bottom surface, and is sprayed into the inside of the nozzle so as to flow along the surface of the protective plate facing the nozzle toward the laser center axis. As a result, when sputtering occurs during laser processing, the sputtering is blocked by the shielding gas flowing along the surface of the protective plate facing the nozzle toward the laser central axis, thereby preventing the sputtering from adhering to the protective plate.

[0013] In the laser processing torch according to an embodiment of the present invention, the protective plate fixing structure has one or more wall guide surfaces which are wall surfaces facing the side surfaces of the protective plate, The shielding gas supplied by the shielding gas supply equipment is guided from the inside of the torch body to one or more wall side guide passages, which are passages having a cross section defined by a gap between the side of the protective plate and the one or more wall side guide surfaces facing that side, and is then guided to one or more guide passages communicating with the one or more wall side guide passages, and is sprayed into the inside of the nozzle so as to flow along the surface of the protective plate facing the nozzle toward the laser center axis. In the configuration of the above embodiment, the protective plate fixing structure has one or more wall-side guide surfaces which are wall surfaces facing the side surfaces of the protective plate. The shielding gas supplied by the shielding gas supply equipment is guided from the inside of the torch body to one or more wall side guide passages, which are passages having a cross section defined by a gap between the side of the protective plate and the one or more wall side guide surfaces facing that side, and is then guided to one or more guide passages communicating with the one or more wall side guide passages, and is sprayed into the inside of the nozzle so as to flow along the surface of the protective plate facing the nozzle toward the laser center axis. As a result, when sputtering occurs during laser processing, the sputtering is blocked by the shielding gas flowing along the surface of the protective plate facing the nozzle toward the laser central axis, thereby preventing the sputtering from adhering to the protective plate.

[0014] In the laser processing torch according to an embodiment of the present invention, the protective plate fixing structure has a plurality of wall side guide grooves, which are grooves having a wall surface facing a side surface of the protective plate as a bottom surface, The shielding gas supplied by the shielding gas supply equipment is guided from the inside of the torch body to a plurality of wall side guide passages, which are passages having as their cross section a gap surrounded by the side of the protective plate and the plurality of wall side guide grooves having as their bottom surface the wall surface facing the side, and is then guided to one or more guide passages communicating with the plurality of wall side guide passages, and is sprayed into the inside of the nozzle so as to flow toward the laser center axis along the surface of the protective plate facing the nozzle. In the configuration of the above embodiment, the protective plate fixing structure has a plurality of wall side guide grooves, which are grooves having as their bottom surfaces the wall surfaces facing the side surfaces of the protective plate. The shielding gas supplied by the shielding gas supply equipment is guided from the inside of the torch body to a plurality of wall side guide passages, which are passages having as their cross section a gap surrounded by the side of the protective plate and a plurality of the wall side guide grooves, each having a bottom surface that faces the side of the protective plate, and is then guided to one or more guide passages communicating with the plurality of wall side guide passages, and is sprayed into the inside of the nozzle so as to flow toward the laser center axis along the surface of the protective plate facing the nozzle. As a result, when sputtering occurs during laser processing, the sputtering is blocked by the shielding gas flowing along the surface of the protective plate facing the nozzle toward the laser central axis, thereby preventing the sputtering from adhering to the protective plate.

[0015] In the laser processing torch according to an embodiment of the present invention, when viewed from the nozzle side toward the surface of the protective plate, a number of flow center lines, which are the center lines of the direction in which the shielding gas flows in the multiple guide passages, extend from the side of the protective plate and intersect with the laser central axis. In the configuration of the above embodiment, when one looks from the nozzle side toward the surface of the protective plate, multiple flow center lines, which are the center lines of the direction in which the shielding gas flows in the multiple guide passages, extend from the side of the protective plate and intersect with the laser central axis. As a result, when sputtering occurs during laser processing, the sputtering is blocked by the shielding gas flowing along the surface of the protective plate facing the nozzle toward the laser central axis, thereby preventing the sputtering from adhering to the protective plate.

[0016] In the laser processing torch according to an embodiment of the present invention, when one looks from the nozzle side toward the surface of the protective plate, multiple flow center lines, which are the center lines of the direction in which the shielding gas flows in the multiple guide passages, extend from the side of the protective plate and are each eccentric in the same direction from the laser central axis. In the configuration of the above embodiment, when one looks from the nozzle side toward the surface of the protective plate, multiple flow center lines, which are the center lines of the direction in which the shielding gas flows in the multiple guide passages, extend from the side of the protective plate and are each eccentric in the same direction from the laser central axis. As a result, when sputtering occurs during laser processing, the sputtering is blocked by the shielding gas flowing along the surface of the protective plate facing the nozzle toward the laser central axis, thereby preventing the sputtering from adhering to the protective plate. Effect of the Invention

[0017] As described above, the laser processing torch according to the present invention has the following effects due to its configuration. The shielding gas is guided from the inside of the torch body into one or more guide passages, which are passages having as their cross section a gap between the surface of the protective plate facing the nozzle and the one or more guide surfaces facing that surface, and is sprayed out into the inside of the nozzle, where it flows along the surface of the protective plate facing the nozzle toward the laser central axis.Therefore, spatter that jumps during laser processing is blocked by the shielding gas flowing along the surface of the protective plate facing the nozzle toward the laser central axis, thereby preventing the spatter from adhering to the protective plate. The shielding gas is guided from the inside of the torch body into a plurality of guide passages, which are passages having a cross section defined by a gap surrounded by the surface of the protective plate facing the nozzle and the plurality of guide grooves, each having a bottom surface facing the nozzle, and is sprayed out into the inside of the nozzle, where it flows along the surface of the protective plate facing the nozzle toward the laser central axis.Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing along the surface of the protective plate facing the nozzle toward the laser central axis, thereby preventing the spatter from adhering to the protective plate. The shielding gas is guided from the inside of the torch body to one or more wall side guide passages, which are passages having a cross section defined by a gap between the side of the protective plate and the one or more wall side guide surfaces facing that side, and is then guided to one or more guide passages connected to the one or more wall side guide passages, and sprayed into the inside of the nozzle, where it flows toward the laser central axis along the surface of the protective plate facing the nozzle.Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing toward the laser central axis along the surface of the protective plate facing the nozzle, thereby preventing the spatter from adhering to the protective plate. The shielding gas is guided from the inside of the torch body to a plurality of wall side guide passages, which are passages having a cross section defined by a gap surrounded by the side of the protective plate and a plurality of wall side guide grooves having a bottom surface defined by the wall surface facing the side, and then guided to one or more guide passages communicating with the plurality of wall side guide passages, and is sprayed into the inside of the nozzle, where it flows toward the laser central axis along the surface of the protective plate facing the nozzle.Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing toward the laser central axis along the surface of the protective plate facing the nozzle, thereby preventing the spatter from adhering to the protective plate. The shielding gas is guided from the inside of the torch body to one or more wall side guide passages, which are passages having a cross section that is a gap between the side of the protective plate and the wall surface facing that side, and is then guided to a plurality of guide passages that communicate with the one or more guide passages, and is sprayed into the inside of the nozzle, where it flows along the surface of the protective plate facing the nozzle, following a flow central axis that extends from the side of the protective plate and intersects the laser central axis.Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing toward the laser central axis along the surface of the protective plate facing the nozzle, thereby preventing the spatter from adhering to the protective plate. The shielding gas is guided from the inside of the torch body to one or more wall side guide passages, which are passages having a cross section defined by a gap between the side of the protective plate and the wall surface facing that side, and is then guided to the multiple guide passages connected to the one or more wall side guide passages, and sprayed out, flowing along the surface of the protective plate facing the nozzle, following flow central axes that extend from the side of the protective plate and are each eccentric in the same direction from the laser central axis.Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing toward the laser central axis along the surface of the protective plate facing the nozzle, thereby preventing the spatter from adhering to the protective plate. [Brief description of the drawings]

[0018] [Figure 1] 1 is a side cross-sectional view of a laser processing torch according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an assembly diagram of the laser processing torch according to the embodiment of the present invention. [Diagram 3] 1 is an arrow view of a laser processing torch according to an embodiment of the present invention; [Figure 4] FIG. 2 is a partially enlarged view of the laser processing torch according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described.

[0020] First, laser processing torches Nos. 1 to 3 according to the embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a side cross-sectional view of a laser processing torch according to an embodiment of the present invention. Fig. 2 is an assembly diagram of the laser processing torch according to an embodiment of the present invention. Fig. 3 is an arrow view of the laser processing torch according to an embodiment of the present invention. Fig. 4 is a partially enlarged view of the laser processing torch according to an embodiment of the present invention. The laser processing torches Nos. 1 to 3 according to the embodiments of the present invention are the same in other structures except for the protective plate fixing structure, and will be described with reference to Figs. 1 to 4.

[0021] A laser processing torch according to an embodiment of the present invention is a mechanism for processing a workpiece with a laser. The laser processing torch is composed of a torch body 100, a nozzle 200, a protective plate 300, a protective plate fixing structure 400, and a shielding gas supply device 500.

[0022] The torch body 100 is a mechanism that incorporates a laser optical system 120 and guides the laser light emitted from the laser optical system 120 along a laser central axis CL. The torch body 100 is composed of a torch body main body 110 and a laser optical system 120 . The torch body 110 is a structure that houses a laser optical system 120 . The laser optical system 120 introduces laser light oscillated by a laser oscillator (not shown) through an optical fiber, and emits the laser light to a focal point through a lens. By matching the focal point with the portion to be processed of the wearable object, the portion to be processed of the wearable object can be melted and processed. For example, the processed portion of the workpiece is welded.

[0023] Nozzle 200 is a mechanism that is detachably fixed to the torch body and has an opening for emitting laser light. The nozzle 200 has an opening O at its tip. The laser light is emitted from the laser optical system 120, exits from the opening at the tip of the nozzle 200, and is irradiated onto the portion to be processed of the workpiece. The shielding gas is supplied into the torch body 100 by a shielding gas supply device 500 (described later) and is ejected from an opening at the tip of the nozzle 200 .

[0024] The protective plate 300 is a member for preventing sputters generated from the workpiece from damaging the laser optical system 120. The protective plate 300 is a plate-shaped member made of a material that is transparent to the laser light emitted from the laser optical system and surrounded by a pair of surfaces 311, 312 and a side surface 320, and is installed between the laser optical system 120 and the nozzle 200 inside the torch body 110. For example, the protective plate 300 is made of quartz glass. In the unlikely event that sputters fly into the nozzle 200, the protective plate 300 receives the sputters, thereby preventing damage to the laser optical system 120. If the protective plate 300 receives the sputtering, the protective plate 300 may be damaged or deteriorated by the heat of the sputtering.

[0025] The shielding gas supply device 500 is a device that supplies shielding gas to the side of the torch body 110 on which the laser optical system 120 is located, with the protection plate 300 therebetween as a boundary.

[0026] The protective plate fixing structure 400 is a structure that fixes the protective plate 300 to the torch body main body 110 at a position sandwiched between the laser optical system 120 and the nozzle 200, with a virtual axis F, which is a virtual axis perpendicular to the surface of the protective plate 300, aligned with the laser central axis CL. The protective plate fixing structure 400 may be a structure in which the protective plate 300 is fixed to the torch body main body 110 at a position sandwiched between the laser optical system 120 and the nozzle 200, with a virtual axis F, which is a virtual axis perpendicular to the surface of the protective plate 300, parallel to the laser central axis CL. For example, the protective plate fixing structure 400 is composed of a protective plate fixing outer periphery 410 which is a part of the torch body main body 110 , a protective plate fixing member 420 , and a protective plate holder 430 . The protection plate fixing outer periphery 410 is a member for fixing the protection plate fixing member 420 to the torch body main body 110 . For example, the protective plate fixing outer periphery 410 and the torch body main body 110 may be integrated together. The protection plate fixing member 420 is a member that is supported by the protection plate fixing outer periphery 410 and fixes the protection plate 300. For example, the protection plate fixing member 420 is fixed to the protection plate fixing outer periphery 410 by means of screws. The protection plate holder 430 is a member that is supported by the protection plate fixing member 420 and holds down the protection plate 300 . For example, the protection plate holder 430 is fixed to the protection plate fixing member 420 by means of screws. The protection plate retainer 430 may be provided with one or more notches at a location facing one or more wall-side guide passages W when the protection plate retainer 430 is fixed to the protection plate fixing member 420 with screws. For example, the protection plate holder 430 may be provided with one or more notches at a location facing one or more wall-side guide passages W when the protection plate holder 430 is fixed to the protection plate fixing member 420 with a screw. In this manner, the shielding gas flows from the interior of the torch body 100 through the notches to one or more wall guide passages W communicating with the one or more notches.

[0027] FIG. 4 shows the construction details of the protection plate fixing structure 400 . The protective plate fixing structure 400 has one or more guide surfaces 421 which face the surface 311 of the protective plate 300 facing the nozzle 200 side. The protective plate fixing structure 400 may have a plurality of guide surfaces 421 along the circumference of the protective plate 300 , the guide surfaces being surfaces that face the surface 311 of the protective plate 300 facing the nozzle 200 . The shielding gas supplied by the shielding gas supply device 500 is guided from the inside of the torch body 100 to one or more guide passages H, which are passages having a cross-section defined by a gap sandwiched between the surface 311 facing the nozzle 200 of the protective plate 300 and one or more guide surfaces 421 facing that surface 311, and is sprayed into the inside of the nozzle 200 so as to flow along the surface facing the nozzle 200 of the protective plate 300 toward the laser center axis CL. The shielding gas is then ejected outward from the opening of the nozzle 200 . The shielding gas supplied by the shielding gas supply device 500 may be guided from the inside of the torch body 100 into multiple guide passages H, which are passages having a cross section defined by a gap sandwiched between the surface 311 facing the nozzle 200 of the protective plate 300 and multiple guide surfaces 421 facing that surface 311, and may be sprayed into the inside of the nozzle 200, and may flow along the surface 311 facing the nozzle of the protective plate 300 toward the laser center axis CL. As a result, multiple shielding gas flows are guided into one or more guide passages H, ejected, flow along the surface 311 facing the nozzle 200 of the protective plate 300 toward the laser central axis CL, collide at the position of the laser central axis CL, and redirect the flow from the surface 311 facing the nozzle 200 of the protective plate 300 to the side of the opening of the nozzle 200.

[0028] The protective plate fixing structure 400 may have a plurality of guide grooves 422 which are grooves having as their bottom surface a surface facing the surface 311 of the protective plate 300 facing the nozzle 200 side. The protective plate fixing structure 400 may have a plurality of guide grooves 422 along the circumference of the protective plate 300, the guide grooves having as their bottom surface a surface facing the surface 311 of the protective plate 300 facing the nozzle 200 side. The shielding gas supplied by the shielding gas supply device 500 is guided from the inside of the torch body 100 to a plurality of guide passages H, which are passages having a cross section defined by a gap surrounded by the surface 311 facing the nozzle 200 of the protective plate 300 and a plurality of guide grooves 422 having the surface facing the surface 311 as their bottom surface, and is sprayed into the inside of the nozzle 200 so as to flow along the surface of the protective plate 300 facing the nozzle 200 toward the laser center axis CL. As a result, multiple shielding gas flows are guided into one or more guide passages H, flow along the surface 311 facing the nozzle of the protective plate 300 toward the laser central axis CL, collide at the position of the laser central axis CL, and redirect the flow from the surface 311 facing the nozzle 200 of the protective plate 300 to the side of the opening of the nozzle 200.

[0029] The protection plate fixing structure 400 may have one or more wall side guide surfaces 411 which are wall surfaces facing the side surface 320 of the protection plate 300 . The protective plate fixing structure 400 may have a plurality of wall side guide surfaces 411 along the circumference of the protective plate 300 , which are wall surfaces facing the side surface 320 of the protective plate 300 . For example, a protective plate fixing outer periphery 410 which is a part of the torch body main body 110 has one or more wall side guide surfaces 411 which are wall surfaces facing the side surface 320 of the protective plate 300 . The shielding gas supplied by the shielding gas supply device 500 is guided from the inside of the torch body 100 to one or more wall side guide passages W, which are passages having as their cross section a gap sandwiched between the side surface 320 of the protective plate 300 and one or more wall side guide surfaces 411 facing that side surface 320, and is then guided to one or more guide passages H communicating with the one or more wall side guide passages W, and is sprayed into the inside of the nozzle 200 so as to flow along the surface of the protective plate 300 facing the nozzle 200 toward the side of the laser center axis CL. The shielding gas supplied by the shielding gas supply device 500 is guided from the inside of the torch body 100 to a plurality of wall side guide passages W, which are passages having a cross section defined by a gap between the side surface 320 of the protective plate 300 and a plurality of wall side guide surfaces 411 facing that side surface 320, and is then guided to a plurality of guide passages H communicating with the plurality of wall side guide passages W, and is sprayed into the inside of the nozzle 200 so as to flow along the surface of the protective plate 300 facing the nozzle 200 toward the laser center axis CL. As a result, multiple shielding gas flows are guided into one or more guide passages H that communicate with one or more wall side guide passages W, flow along the surface 311 facing the nozzle 200 of the protective plate 300 toward the laser central axis CL, collide at the position of the laser central axis CL, and redirect the flow from the surface 311 facing the nozzle 200 of the protective plate 300 to the side of the opening of the nozzle 200.

[0030] The protective plate fixing structure 400 has a plurality of wall side guide grooves 412 which are grooves having a wall surface facing the side surface 320 of the protective plate 300 as a bottom surface. The protective plate fixing structure 400 may have a plurality of wall side guide grooves 412 along the circumference of the protective plate 300, the wall surface facing the side surface 320 of the protective plate 300 being a groove having a bottom surface. For example, the protective plate fixing outer periphery 410 which is a part of the torch body main body 110 has a plurality of wall side guide grooves 412 which are grooves having a wall surface facing the side surface 320 of the protective plate 300 as a bottom surface. The shielding gas supplied by the shielding gas supply device 500 may be guided from inside the torch body main body 110 to a plurality of wall side guide passages W, which are passages having a cross section defined by a gap surrounded by the side surface 320 of the protective plate 300 and a plurality of wall side guide grooves 412 having the wall surface facing the side surface 320 as their bottom surface, and then may be guided to one or more guide passages H communicating with the plurality of wall side guide passages W, and may be sprayed into the inside of the nozzle 200 so as to flow along the surface 311 of the protective plate 300 facing the nozzle 200 toward the laser center axis CL. The shielding gas supplied by the shielding gas supply equipment 500 is guided from inside the torch body main body 110 to a plurality of wall side guide passages W, which are passages having a cross section defined by a gap surrounded by the side surface 320 of the protective plate 300 and a plurality of wall side guide grooves 412 having the wall surface facing the side surface 320 as their bottom surface, and is then guided to a plurality of guide passages H which are connected to the plurality of wall side guide passages W (respectively), and is sprayed into the inside of the nozzle 200 so as to flow along the surface 311 facing the nozzle 200 side of the protective plate 300 toward the laser center axis CL. As a result, multiple shielding gas flows are guided into multiple guide passages H that are connected (respectively) to multiple wall-side guide passages W, flow along the surface 311 facing the nozzle side of the protective plate 300 toward the laser central axis CL, collide at the position of the laser central axis CL, and redirect the flow from the surface 311 facing the nozzle 200 side of the protective plate 300 to the side of the opening of the nozzle 200.

[0031] Hereinafter, variations in the shape of the protection plate fixing structure 400 when it has a plurality of guide passages H and a plurality of wall side guide passages W will be described with reference to the drawings. FIG. 2 shows a cross-sectional side view of the protection plate fixing structure 400 before assembly. FIG. 3 shows a side plan view of the protection plate fixing structure 400 before assembly. 2 and 3, the protective plate fixing peripheral portion 410 is omitted.

[0032] Figures 2 and 3 (A) show that multiple guide passages H are each sandwiched between surface 311 of protective plate 300 and multiple guide surfaces 421, which are the surfaces facing surface 311, and multiple wall side guide passages W are each sandwiched between side surface 320 of protective plate 300 and multiple wall side guide surfaces 411, which are the surfaces facing side surface 320. The eight wall guide passages W communicate with the eight guide passages H.

[0033] Figures 2 and 3 (B) show that the multiple guide passages H are surrounded by the surface 311 of the protective plate 300 and multiple guide grooves 422 having their bottom surfaces facing the surface 311, and the multiple wall side guide passages W are surrounded by the side surface 320 of the protective plate 300 and multiple wall side guide grooves 412 having their bottom surfaces facing the side surface 320. The eight wall guide passages W communicate with the eight guide passages H. When one looks from the nozzle 200 side toward the surface 311 of the protective plate 300, multiple flow center lines, which are the center lines of the direction in which the shielding gas flows in the multiple guide passages H, extend from the side 311 of the protective plate 300 and intersect with the laser central axis CL. As a result, multiple shielding gas flows are guided into multiple guide passages H that are connected (respectively) to multiple wall side guide passages W, flow along the surface 311 facing the nozzle 200 of the protective plate 300 toward the laser central axis CL, collide at the position of the laser central axis CL, and flow from the surface 311 facing the nozzle 200 of the protective plate 300 to the side of the opening of the nozzle 200.

[0034] Figures 2 and 3 (C) show that the multiple guide passages H are surrounded by the surface 311 of the protective plate 300 and multiple guide grooves 422 having the surface facing the surface 311 as their bottom surface, and the multiple wall side guide passages W are surrounded by the side surface 320 of the protective plate 300 and the wall side guide groove 412 having the surface facing the side surface 320 as their bottom surface. The four wall guide passages W communicate with the four guide passages H. When the line of sight is viewed from the nozzle 200 side toward the surface 311 of the protective plate 300, a plurality of flow center lines, which are the center lines of the direction in which the shielding gas flows in the plurality of guide passages H, extend from the side surface 320 of the protective plate 300 and are each eccentric in the same direction from the laser central axis CL. As a result, multiple shielding gas flows are guided into multiple guide passages H that are connected (respectively) to multiple wall side guide passages W, flow along the surface 311 facing the nozzle 200 of the protective plate 300 toward the laser central axis CL, collide at the position of the laser central axis CL, and then rotate from the surface 311 facing the nozzle 200 of the protective plate 300 to flow toward the opening of the nozzle 200.

[0035] As a result of the above structure, when spatter flies into the inside of the nozzle 200, the spatter is pushed back toward the nozzle 200 by the flow of shielding gas flowing from the surface 311 of the protective plate 300 facing the nozzle 200 to the side of the opening of the nozzle 200. In addition, when the shielding gas is ejected from one or more guide passages H provided along the surface 311 of the protective plate 300 facing the nozzle 200 toward the central axis of the protective plate, the pressure of the shielding gas drops suddenly. As a result, the temperature of the shielding gas drops due to the adiabatic expansion phenomenon. Therefore, a cooling effect due to the drop in temperature of the shielding gas occurs on the surface 311 of the protective plate 300 facing the nozzle 200 and its vicinity, and the protective plate 300 and the members in its vicinity are cooled. By selecting the cross-sectional area of ​​the one or more guide passages H, a desired temperature drop in the shielding gas can be obtained. As a result, damage and deterioration of the protection plate 300 caused by sputtering can be suppressed.

[0036] As described above, the use of the laser processing torch according to the embodiment of the present invention has the following effects. The shielding gas is guided from the inside of the torch body 100 into one or more guide passages H, which are passages having as their cross section a gap between the surface 311 of the protective plate 300 facing the nozzle 200 and one or more guide surfaces 421 facing that surface 311, and is sprayed into the inside of the nozzle 200, where it flows along the surface 311 of the protective plate 300 facing the nozzle 200 toward the laser central axis CL. Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing along the surface 311 of the protective plate 300 facing the nozzle 200 toward the laser central axis CL, thereby preventing the spatter from adhering to the protective plate 300. The shielding gas is guided from the inside of the torch body 100 through multiple guide passages H, which are passages having a cross section defined by a gap surrounded by surface 311 facing the nozzle 200 of the protective plate 300 and multiple guide grooves 422 having a bottom surface facing that surface 311, and is sprayed out into the inside of the nozzle 200, and flows along surface 311 facing the nozzle 200 of the protective plate 300 toward the laser central axis CL. Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing along surface 311 facing the nozzle 200 of the protective plate 300 toward the laser central axis CL, thereby preventing the spatter from adhering to the protective plate 300. The shielding gas is guided from the inside of the torch body 100 to one or more wall side guide passages W, which are passages having a cross section defined by a gap between side surface 320 of the protective plate 300 and one or more wall side guide surfaces 411 facing the side surface 320, and then guided to one or more guide passages H communicating with the one or more wall side guide passages W, and sprayed into the inside of the nozzle 200, where it flows toward the laser central axis CL along surface 311 facing the nozzle 200 of the protective plate 300.Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing toward the laser central axis CL along surface 311 facing the nozzle 200 of the protective plate 300, thereby preventing the spatter from adhering to the protective plate 300. The shielding gas is guided from the inside of the torch body 100 to a plurality of wall side guide passages W, which are passages having a cross section defined by a gap surrounded by the side surface 320 of the protective plate 300 and a plurality of wall side guide grooves 412 having as their bottom surfaces the wall surface facing the side surface 320, and then is guided to one or more guide passages H communicating with the plurality of wall side guide passages W, and is sprayed into the inside of the nozzle 200, and flows toward the laser central axis CL along the surface 311 of the protective plate 300 facing the nozzle 200.Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing toward the laser central axis along the surface of the protective plate facing the nozzle, so that the spatter can be prevented from adhering to the protective plate 300. The shielding gas is guided from the inside of the torch body 100 to a plurality of wall side guide passages W, which are passages having a cross section defined by a gap surrounded by the side surface 320 of the protective plate 300 and a plurality of wall side guide grooves 412 having as their bottom surfaces the wall surface facing the side surface 320, and then guided to a plurality of guide passages H which are connected to (respectively) the plurality of wall side guide passages W, and is sprayed into the inside of the nozzle 200, and flows toward the laser central axis CL along the surface 311 of the protective plate 300 facing the nozzle 200.Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing toward the laser central axis CL along the surface 311 of the protective plate 300 facing the nozzle 200, so that the spatter can be prevented from adhering to the protective plate 300. The shielding gas is guided from the inside of the torch body 100 to one or more wall side guide passages W, which are passages having a cross section defined by a gap between the side surface 320 of the protective plate 300 and the wall surface facing that side surface 320, and then guided to a plurality of guide passages H communicating with the one or more wall side guide passages W, and is ejected into the nozzle 200 so as to flow toward the laser central axis CL along the surface 311 of the protective plate 300 facing the nozzle 200, and flows along the flow central axis that extends from the side surface 320 of the protective plate 300 along the surface 311 facing the nozzle 200 and intersects with the laser central axis CL. Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing toward the laser central axis CL along the surface 311 of the protective plate 300 facing the nozzle 200, and adhesion of the spatter to the protective plate 300 can be suppressed. The shielding gas is guided from the inside of the torch body 100 to one or more wall side guide passages W, which are passages having a cross section defined by a gap between the side surface 320 of the protective plate 300 and the wall surface facing that side surface 320, and then is guided to one or more guide passages H communicating with the wall side guide passages W, and is sprayed out, following the flows that extend from the side surface 320 of the protective plate 300 along the surface 311 facing the nozzle 200 of the protective plate 300 and are eccentric in the same direction from the laser central axis CL. Therefore, when spatter jumps during laser processing, the spatter is blocked by the shielding gas flowing toward the laser central axis CL along the surface 311 of the protective plate 300 facing the nozzle 200, and adhesion of the spatter to the protective plate 300 can be suppressed.

[0037] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the invention. Although a structure in which a plurality of guide grooves and a plurality of wall side guide grooves are formed in the protective plate fixing structure has been described as an example, a plurality of guide grooves and a plurality of wall side guide grooves may be formed in the side surface 320 of the protective plate 300 . Although the protective plate fixing outer periphery 410 has been described as being a part of the torch body main body 110, the present invention is not limited to this. For example, the protective plate fixing outer periphery 410 may be a structure separate from the torch body main body 110 and fixed to the torch body main body 110 by screws. [Explanation of symbols]

[0038] H Guideway W wall guide passage F Virtual axis CL Laser central axis K flow centerline O opening 100 Torch Body 110 Torch body 120 Laser Optical System 200 nozzles 300 Protection Plate 311 Nozzle side surface 312 Surface on the side of the laser optics 320 Side 400 Protective plate fixing structure 410 Protective plate fixed outer periphery 411 Wall guide surface 412 Wall guide groove 420 Protective plate fixing member 421 Guide Surface 422 Guide groove 430 Protective plate holder 500 Shielding gas supply mechanism [Prior art documents] [Patent documents]

[0039] [Patent Document 1] JP 2005-219108 A [Patent Document 2] Patent Publication No. 2007-216290 [Patent Document 3] Patent Publication No. 2012-192420 [Patent Document 4] WO2010 / 113244

Claims

1. A laser processing torch for processing a workpiece with a laser, a torch body that incorporates a laser optical system and guides a laser beam emitted from the laser optical system along a central axis of the laser; a nozzle having an opening for emitting a laser beam, the nozzle being detachably fixed to the torch body; a protective plate that is a plate-like member that is made of a material that is transparent to laser light and is surrounded by a pair of front and side surfaces and is installed inside the torch body; a shielding gas supply device for supplying a shielding gas to a side of the torch body where the laser optical system is located, the side being separated by the protective plate; a protective plate fixing structure that fixes the protective plate to the torch body at a position sandwiched between the laser optical system and the nozzle, with a virtual axis that is a virtual axis perpendicular to a surface of the protective plate aligned with a laser central axis; Equipped with the protective plate fixing structure has one or more guide surfaces that face a surface of the protective plate facing the nozzle; the shielding gas supplied by the shielding gas supply device is guided from inside the torch body to one or more guide passages which are passages having, as a cross section, a gap between the surface of the protective plate facing the nozzle and the one or more guide surfaces facing said surface, and is ejected into the nozzle so as to flow along the surface of the protective plate facing the nozzle toward the laser central axis; A laser processing torch characterized by:

2. the protective plate fixing structure has a plurality of guide grooves, which are grooves having a bottom surface facing the surface of the protective plate facing the nozzle; the shielding gas supplied by the shielding gas supply device is guided from the inside of the torch body to a plurality of guide passages, which are passages having, as their cross sections, gaps surrounded by the surface of the protective plate facing the nozzle and the plurality of guide grooves having a bottom surface facing the surface, and is ejected into the inside of the nozzle so as to flow toward the laser central axis along the surface of the protective plate facing the nozzle.

2. The laser processing torch according to claim 1 .

3. The protective plate fixing structure has one or more wall side guide surfaces which are wall surfaces facing the side surfaces of the protective plate, The shielding gas supplied by the shielding gas supply device is guided from the inside of the torch body to one or more wall side guide passages, which are passages having a cross section defined by a gap between a side surface of the protective plate and one or more wall side guide surfaces facing the side surface, and then: the gas is guided by one or more guide passages communicating with one or more wall-side guide passages, and jets into the nozzle so as to flow along a surface of the protective plate facing the nozzle toward a side of a laser central axis; 3. The laser processing torch according to claim 1 or 2.

4. The protective plate fixing structure has a plurality of wall side guide grooves, which are grooves having a wall surface facing a side surface of the protective plate as a bottom surface, The shielding gas supplied by the shielding gas supply device is guided from inside the torch body to a plurality of wall-side guide passages, which are passages having a cross section of a gap surrounded by a side surface of the protective plate and a plurality of wall-side guide grooves having a bottom surface that is a wall surface facing the side surface, and then the gas is guided by one or more guide passages communicating with the plurality of wall-side guide passages, and jets out into the nozzle so as to flow along a surface of the protective plate facing the nozzle toward a side of a laser central axis; 3. The laser processing torch according to claim 1 or 2.

5. When the line of sight is seen from the nozzle side toward the surface of the protective plate, a plurality of flow center lines, which are center lines in the directions in which the shielding gas flows through the plurality of guide passages, extend from the side of the protective plate and intersect with the laser central axis.

3. The laser processing torch according to claim 2.

6. When viewed from the nozzle side toward the surface of the protective plate, a plurality of flow center lines, which are center lines in the directions in which the shielding gas flows through the plurality of guide passages, extend from the side of the protective plate and are each eccentric in the same direction from the laser central axis.

3. The laser processing torch according to claim 2.

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