JP6678402B2 - Laser welding method and laser welding machine - Google Patents

Description

  The present invention relates to a laser welding method and a laser welding machine.

  Resistance spot welding has mainly been used to form stainless steel railcar structures. As a welding location in a railway vehicle structure, for example, a welding between an outer plate and an entrance / exit frame is given. The entrance / exit frame is a portion where a door of the vehicle is arranged, and is required to be watertight so that rain or the like does not enter the vehicle. In resistance spot welding, it is difficult to ensure the watertightness of the work by the welded portion itself, and therefore, a resin seal is arranged corresponding to the welding location to ensure the watertightness. However, the resin seal deteriorates quickly and maintenance for maintaining water tightness is indispensable.

  In recent years, attention has been paid to laser welding as a technique capable of ensuring the watertightness of a work by a welded portion itself in response to such a problem. For example, in a railway vehicle structure described in Patent Literature 1, an end of an entrance frame is overlapped with an outer surface of an end of an outer plate, and the end of the entrance frame and a main surface of the outer plate are continuously welded by laser welding. ing.

JP 2007-112343 A

  At present, in performing laser welding, a welding machine that automatically scans a laser beam along a scheduled welding line is used. However, in the automatic welding, when welding three-dimensional workpieces like the above-described welding of the outer plate and the entrance / exit frame, it is difficult to secure the following property of laser light (easiness to follow the scheduled welding line). There is a problem. In order to ensure the following of laser light in automatic welding, it is necessary to teach (input machining coordinates to a computer) each time multiple points according to the shape of the work. It has become.

  The present invention has been made to solve the above-described problems, and has as its object to provide a laser welding method and a laser welding apparatus capable of welding a work in a watertight manner with good workability.

  In order to solve the above-described problems, a laser welding method according to one aspect of the present invention uses an arrangement step of superposing an end of a second work on a main surface of a first work, and a hand torch type laser welding machine. A welding step of forming a continuous laser welded portion along the overlapped portion on the main surface of the first work and the end surface on the end side of the second work, and in the welding process, A first contact tip having a convex portion formed by a first surface in contact with a main surface of a work and a second surface in contact with an end surface of a second work is applied to a torch portion of a laser welding machine. And laser welding of the end face.

  In this laser welding method, the main surface of the first work and the end surface of the second work are laser-welded using a hand torch type laser welding machine. By forming a continuous laser welded portion on the main surface of the first work and the end surface on the end side of the second work by laser welding, the water tightness of the work can be sufficiently ensured. Also, in this laser welding method, by using a hand torch type laser welding machine, unlike in the case of automatic welding, complicated teaching work to ensure the following of laser light is not required, and the workability of welding is improved. Can be improved. In performing laser welding by hand while holding the torch portion, the first surface of the first contact tip applied to the torch portion is in contact with the main surface of the first work, and the second surface is the second surface of the second work. Touch the end face. For this reason, the main surface of the first work and the end surface of the second work serve as guides, and it is possible to suppress the hand at hand gripping the torch portion. Therefore, it is possible to prevent the laser light from being damaged.

  Further, the first contact chip may be further formed with a notch at a corner formed by the first surface and the second surface. In this case, even when burrs or the like are present on the end face of the second work, it is possible to preferably perform manual scanning of the torch portion by avoiding collision of the burrs with the first contact chip by the cutout portion. .

  Further, the first contact chip may be formed of a conductive material. In this case, for example, by attaching a ground to the work, the interlock function of the laser welding machine can be realized depending on the presence or absence of energization. Thereby, the safety of the laser welding operation can be improved.

  Further, the method further includes a processing step of chamfering an end portion of the second work, and in the processing step, the first surface in contact with the main surface of the second work and the second surface in contact with the end surface of the second work. The second contact tip having the formed concave portion may be applied to a torch portion of a laser welding machine to perform chamfering of an end portion. In this chamfering process, the first surface of the second contact chip applied to the torch portion is in contact with the main surface of the second work, and the second surface is in contact with the end surface of the second work. For this reason, the main surface and the end surface of the second work serve as guides, and it is possible to suppress the hand at hand gripping the torch portion.

  Further, the second contact chip may further have a third surface that is in contact with the main surface of the first work. In this case, the main surface of the first work further serves as a guide, and it is possible to more surely prevent the hand from gripping the torch portion.

  Further, the second contact chip may further be formed with a notch at a corner formed by the first surface and the second surface. In this case, even when burrs or the like are present on the end face of the second work, scanning of the torch portion can be suitably performed by avoiding collision of the burrs with the second contact chip by the cutout portion.

  Further, the second contact chip may be formed of a conductive material. In this case, for example, by attaching a ground to the work, it is possible to realize an interlock mechanism of the laser welding machine depending on the presence or absence of energization. Thereby, the safety of the laser welding operation can be improved.

  In the welding step, a laser weld may be formed by irradiating a pulse laser from a laser welding machine. In the case of using a CW laser, if scanning of the torch portion is stopped during welding, a hole may be opened in the work at the stopped position. On the other hand, when the pulse laser is used, even if the scanning of the torch portion is stopped during welding, a hole is prevented from being opened in the work at the stopped position, and laser welding can be resumed from that position.

  In addition, the first work is a frame member that holds an opening in the railway vehicle structure, and the second work is an outer plate of the railway vehicle structure. The boards may be overlaid. In the case where such a joined body of works is applied to a railway vehicle structure, a good appearance can be formed without overhang by the thickness of the entrance frame on the side structure of the railway vehicle.

  Further, a laser welding machine according to one aspect of the present invention is a hand torch type in which a continuous laser weld is formed along a portion where a main surface of a first work and an end of a second work overlap. A laser welding machine, capable of attaching a first contact tip having a convex portion formed by a first surface in contact with a main surface of a first work and a second surface in contact with an end surface of a second work. With a torch part.

  In this laser welding machine, a continuous laser welded portion is formed at an overlapping portion between the main surface of the first work and the end surface on the end side of the second work, so that the work is made watertight at the overlapping portion. Nature can be sufficiently secured. In addition, unlike the automatic welding, this laser welding machine does not require a complicated teaching operation for ensuring the laser beam following property, thereby improving the welding workability. In performing laser welding by hand while holding the torch portion, the first surface of the first contact tip applied to the torch portion is in contact with the main surface of the first work, and the second surface is the second surface of the second work. Touch the end face. For this reason, the main surface of the first work and the end surface of the second work serve as guides, and it is possible to suppress the hand at hand gripping the torch portion. Therefore, it is possible to prevent the laser light from being damaged.

  Further, the first contact chip may be further formed with a notch at a corner formed by the first surface and the second surface. In this case, even when burrs or the like are present on the end face of the second work, scanning of the torch portion can be suitably performed by avoiding collision of the burrs with the first contact chip by the cutout portion.

  Further, the first contact chip may be formed of a conductive material. In this case, for example, by attaching a ground to the work, it is possible to realize an interlock mechanism of the laser welding machine depending on the presence or absence of energization. Thereby, the safety of the laser welding operation can be improved.

  Further, the torch portion can attach a second contact chip having a concave portion formed by a first surface in contact with the main surface of the second work and a second surface in contact with the end surface of the second work. You may. In the chamfering process using the second contact chip, the first surface of the second contact chip applied to the torch portion is in contact with the main surface of the second work, and the second surface is in contact with the end surface of the second work. For this reason, the main surface and the end surface of the second work serve as guides, and it is possible to suppress the hand at hand gripping the torch portion.

  Further, the second contact chip may further have a third surface that is in contact with the main surface of the first work. In this case, the main surface of the first work further serves as a guide, and it is possible to more surely prevent the hand from gripping the torch portion.

  Further, the second contact chip may further be formed with a notch at a corner formed by the first surface and the second surface. In this case, even when burrs or the like are present on the end face of the second work, scanning of the torch portion can be suitably performed by avoiding collision of the burrs with the second contact chip by the cutout portion.

  Further, the second contact chip may be formed of a conductive material. In this case, for example, by attaching a ground to the work, it is possible to realize an interlock mechanism of the laser welding machine depending on the presence or absence of energization. Thereby, the safety of the laser welding operation can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, a work can be welded watertight with favorable workability.

It is a schematic front view showing one embodiment of a laser welding machine concerning the present invention. FIG. 2 is a sectional view illustrating an example of a joined body formed using the laser welding machine illustrated in FIG. 1. FIG. 3 is a cross-sectional view illustrating an example of an arrangement process in a laser welding method for manufacturing the joined body illustrated in FIG. 2. It is a figure showing an example of the 1st contact tip applied to a laser welding machine in a welding process. It is sectional drawing which shows an example of a welding process. It is a figure showing an example of the 2nd contact tip applied to a laser welding machine in a processing process. It is sectional drawing which shows an example of a process.

  Hereinafter, preferred embodiments of a laser welding method and a laser welding apparatus according to one aspect of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic front view showing one embodiment of a laser welding machine according to the present invention. As shown in FIG. 1, the laser welding machine 1 is configured as a device for laser welding workpieces along a predetermined scheduled welding line. The laser welding machine 1 is a so-called hand torch type laser welding machine, for example, a box-shaped main body 2 having a built-in fiber laser oscillator, and a torch provided at a distal end of a flexible cable 3 extending from the main body 2. Unit 4.

  The main body 2 is a part that incorporates a computer system including a CPU, a memory, a communication interface, a hard disk, and the like, and controls laser oscillation conditions and the like. A display 5 is installed on the upper surface side of the main body 2. The display 5 displays setting values of various conditions such as an output value and a pulse width of a laser beam, an actual temperature and an actual output value of a laser oscillator, and the like. A caster 6 is provided on the bottom surface side of the main body 2 so that the laser welding machine 1 is movable.

  The torch part 4 is a part for emitting laser light from the fiber laser oscillator to the outside. The torch part 4 has a substantially cylindrical shape with an outer diameter that is easy for a worker performing laser welding to grasp. Non-slip, protective glass, and the like are provided on the peripheral surface of the torch 4. A contact tip 7 is detachably attached to the tip of the torch 4. The contact chip 7 is a hollow cylindrical member, and the laser light that has passed through the torch 4 is emitted from the tip of the contact chip 7 to the outside. In the laser welding machine 1, contact tips 7 having different tip shapes are prepared according to the welding object and application.

  The laser welding machine 1 is provided with safety glasses (not shown). The left and right lenses of the protective glasses are provided with a function of cutting light having a wavelength corresponding to the laser light emitted from the torch 4. By wearing such protective glasses, it is possible to prevent laser light (or reflected light thereof) from directly entering the eyes of an operator during laser welding, and to improve worker safety during laser welding. Improvement is achieved. Further, it is preferable that the laser welding machine 1 is provided with a ground for an interlock mechanism.

  FIG. 2 is a sectional view showing an example of a joined body formed using a laser welding machine. As shown in the figure, a joint body 11 exemplified in the present embodiment is a joint formed by welding an entrance / exit frame (first work) 12 of a stainless steel railway vehicle to an outer plate (second work) 13. Body.

  The entrance / exit frame 12 is a frame member that forms an arrangement space for a door provided in a side structure of the railway vehicle. The entrance / exit frame 12 is formed of, for example, stainless steel having a thickness of about 1.0 mm to 6.0 mm. One end of the entrance / exit frame 12 is a flat portion 14, and the other end is a bent portion 15 bent from the flat portion 14. The outer plate 13 is a flat plate member that forms an outer portion of the side structure of the railway vehicle. The outer plate 13 is formed of, for example, stainless steel having a thickness of about 1.0 mm to 3.0 mm. The outer plate 13 is thinner than the entrance frame 12, for example, but there is no particular limitation on the size relationship of the thickness. The outer plate 13 and the entrance frame 12 may have the same thickness.

  The joined body 11 is applied to a railway vehicle structure such that the bending direction of the bent portion 15 faces the inside of the vehicle. In the present embodiment, the end 16 of the outer plate 13 is overlapped with the vehicle outer side surface (main surface) 14 a of the flat portion 14 in the entrance frame 12. Laser welding or resistance spot welding is performed on the overlapping portion P of the entrance frame 12 and the outer plate 13, and a predetermined direction is set along the extending direction of the overlapping portion P (here, the depth direction in FIG. 2). Are formed at intervals of.

  Fillet welding by laser welding is performed on the vehicle outer side surface 14a of the entrance / exit frame 12 and the end surface 16a of the outer plate 13 on the end portion 16 side, and is continuous along the extending direction of the overlapped portion P. Laser welding part W2 is formed. By forming such a continuous laser welded portion W2, the doorway frame 12 and the outer plate 13 are firmly and watertightly joined.

  A chamfering process is performed on a corner 16 b of the outer plate 13 at the end 16 on the vehicle outside. In the joined body 11, the outer panel 13 is superimposed on the outside of the vehicle of the entrance frame 12, and compared with the case where the entrance frame 12 is superimposed on the outer side of the vehicle, the entrance frame is provided on the side structure of the railway vehicle. No overhang corresponding to the thickness of 12 occurs, and a good appearance can be formed. On the other hand, since the end 16 of the outer panel 13 is located near the entrance frame 12, in a railway vehicle in which the joined body 11 is applied to the side structure, there is a possibility that a passenger or the like may touch the end 16 of the outer panel 13. is there. Therefore, it is preferable that the corner 16b of the outer plate 13 be rounded by chamfering.

  Subsequently, a manufacturing process of the above-described joined body 11 will be described.

  In manufacturing the joined body 11, first, as shown in FIG. 3, an entrance frame 12 and an outer plate 13 are prepared, and an end 16 of the outer plate 13 is overlapped on a vehicle outer surface 14 a of the entrance frame 12 (arrangement). Process). Next, using a resistance spot welding machine or the like, a spot welded portion W1 is formed at the overlapped portion P of the entrance frame 12 and the outer plate 13.

  After the formation of the spot welding portion W1, a continuous laser welding portion W2 is formed along the overlapping portion P of the vehicle outer surface 14a of the entrance frame 12 and the end surface 16a of the outer plate 13 on the end portion 16 side (welding). Process). FIG. 4 is a diagram showing an example of the first contact tip 7A applied to the laser welding machine in the welding process. As shown in the figure, the first contact chip 7A is formed of, for example, a conductive material and has a hollow cylindrical shape. The conductive material forming the first contact chip 7A is preferably a material having a lower hardness than the material forming the work, from the viewpoint of preventing the work from being damaged. Examples of such a conductive material include copper, a copper alloy, and conductive carbon.

  The first contact chip 7A is designed to contact the workpiece at a predetermined inclination angle. Here, the first contact chip 7A is designed to contact the entrance frame 12 and the outer plate 13 at an angle of 45 °. When the first contact tip 7A is attached to the tip of the torch part 4, the light of the laser light guided from the center axis L1 of the first contact tip 7A and the main body part 2 of the laser welding machine 1 is provided. It is designed so that the axis substantially coincides with the axis.

  On the tip end side of the first contact chip 7A, a convex portion 21 and a notch portion 22 are provided. The convex portion 21 is a portion that comes into contact with the workpiece during laser welding. The convex portion 21 includes a first surface 23 that contacts the vehicle outer surface 14 a of the entrance frame 12 and a second surface 24 that contacts the end surface 16 a of the outer plate 13. The first surface 23 and the second surface 24 make a substantially right angle at the tip of the first contact chip 7A. A corner 25 formed by the first surface 23 and the second surface 24 is located on the center axis L1 of the first contact chip 7A. An R-shaped notch 26 is provided in the corner 25.

  The cutout portion 22 is a portion that discharges welding fume generated from the workpiece during laser welding to the outside of the first contact tip 7A. The welding fume is dust that is formed by solidification of metal vapor generated on the surface of a workpiece during welding in the air. The notch 22 is formed by cutting a part of the peripheral surface of the first contact chip 7 </ b> A into a rectangle continuous with the second surface 24. The notch 22 exposes the internal space in the vicinity of the convex portion 21 to the outside even when the convex portion 21 is in contact with the work, thereby forming a welding fume discharge path.

  In the welding step, the first contact tip 7A is attached to the tip of the torch 4 as shown in FIG. Then, the torch part 4 is held at an angle of about 45 ° with respect to the entrance frame 12 and the outer plate 13, and the first surface 23 of the convex portion 21 of the first contact chip 7 </ b> A is attached to the vehicle outer surface 14 a of the entrance frame 12. At the same time, the second surface 24 is brought into contact with the end surface 16 a of the outer plate 13. The notch 26 of the first contact chip 7A faces a corner formed by the vehicle outer surface 14a of the entrance frame 12 and the end surface 16a of the outer plate 13.

  In this state, a laser beam is emitted from the torch portion 4 and the torch portion 4 is manually scanned along the overlapping portion P between the vehicle outer side surface 14a of the entrance frame 12 and the end portion 16 of the outer plate 13. As a result, a continuous laser welded portion W2 is formed along the overlapped portion P. As a result, the vehicle outer side surface 14a of the doorway frame 12 and the end surface 16a of the outer plate 13 are fillet-welded, and the laser beam welded portion W2 joins the doorway frame 12 and the outer plate 13 in a watertight and strong manner.

  In the welding step, it is preferable that the ground of the laser welding machine 1 is connected to the entrance frame 12 or the outer plate 13. In this case, since the first contact tip 7A is formed of a conductive material such as copper or conductive carbon, the laser welding machine 1 is turned on based on the state of conduction of the circuit via the torch 4, the work, and the ground. An interlock mechanism can be realized. For example, when the first contact tip 7A is not in contact with the work and the energization state of the circuit is off, the emission of laser light from the laser welding machine 1 is prohibited, thereby ensuring work safety. Can be secured.

  After the formation of the laser weld W2, chamfering of the end 16 of the outer plate 13 is performed (processing step). FIG. 6 is a diagram illustrating an example of the second contact tip 7B applied to the laser welding machine in the welding process. As shown in the drawing, the second contact chip 7B is formed of a conductive material such as copper, copper alloy, conductive carbon or the like, like the first contact chip 7A, and has a hollow cylindrical shape. I have.

  The second contact chip 7B is designed to come into contact with the work at a predetermined inclination angle. Here, the second contact chip 7B is designed to contact the entrance frame 12 and the outer plate 13 at an angle of 45 °. When the second contact tip 7B is attached to the tip of the torch 4, the laser light guided from the center axis L2 of the second contact tip 7B and the main body 2 of the laser welding machine 1 is provided. It is designed so that the axis substantially coincides with the axis.

  On the tip side of the second contact chip 7B, a concave portion 31 and a cutout portion 32 are provided. The concave portion 31 is a portion that comes into contact with the workpiece during laser welding. The concave portion 31 includes a first surface 33 that contacts the vehicle outer surface (main surface) 16 c of the outer plate 13 and a second surface 34 that contacts the end surface 16 a of the outer plate 13. The first surface 33 and the second surface 34 form a substantially right angle at the tip of the second contact chip 7B. A corner 35 formed by the first surface 33 and the second surface 34 is located on the central axis L2 of the second contact chip 7B. An R-shaped notch 36 is provided in the corner 35.

  The notch portion 32 is a portion that discharges welding fume generated from a workpiece at the time of laser welding to the outside of the second contact tip 7B, similarly to the notch portion 22 of the first contact tip 7A. The notch 32 is formed by cutting a part of the peripheral surface of the second contact chip 7 </ b> B into a rectangle continuous with the first surface 33. The notch 32 exposes the internal space near the concave portion 31 to the outside even when the concave portion 31 is in contact with the work, thereby forming a discharge path of welding fume.

  Further, a third surface 37 that is in contact with the vehicle outer side surface 14a of the entrance frame 12 is provided on the distal end side of the second contact tip 7B. The third surface 37 is formed on the opposite side of the notch 32 continuously from the second surface 34. The second surface 34 and the third surface 37 form a substantially right angle at the tip of the second contact chip 7B. A corner 38 formed by the second surface 34 and the third surface 37 is shifted to the opposite side of the notch 32 with respect to the center axis L2 of the second contact chip 7B.

  In the processing step, the above-mentioned second contact chip 7B is attached to the tip of the torch part 4, as shown in FIG. Then, the torch portion 4 is held at an angle of about 45 ° with respect to the entrance frame 12 and the outer plate 13, and the first surface 33 of the concave portion 31 of the second contact chip 7 </ b> B contacts the vehicle outer surface 16 c of the outer plate 13. At the same time, the second surface 34 is brought into contact with the end surface 16 a of the outer plate 13. Further, the third surface 37 of the second contact tip 7B is brought into contact with the vehicle outer side surface 14a of the entrance frame 12. The notch 36 of the second contact chip 7B faces the corner 16b of the end 16 of the outer plate 13.

  In this state, a laser beam is emitted from the torch portion 4 and the torch portion 4 is manually scanned along the overlapping portion P between the vehicle outer side surface 14a of the entrance frame 12 and the end portion 16 of the outer plate 13. Thereby, the corner 16b of the end 16 of the outer plate 13 is processed into an R shape. By chamfering the corner 16b, burrs and the like generated in the corner 16b and the vicinity thereof are also removed at the same time. Through the above steps, the joined body 11 shown in FIG. 2 is obtained.

  In the processing step, it is preferable that the ground of the laser welding machine 1 is connected to the entrance frame 12 or the outer plate 13. Since the second contact chip 7B is also formed of a conductive material such as copper, copper alloy, conductive carbon or the like, the laser welding machine 1 is controlled based on the state of current supply to the circuit via the torch 4, work, and ground. An interlock mechanism can be realized.

  In the above-mentioned process, the doorway frame 12 and the outer plate 13 are joined to each other by the spot welded portion W1 after the disposing process of superposing the doorway frame 12 on the outer plate 13 and before the welding process of forming the laser welded portion W2. ing. When the thickness of the doorway frame 12 is larger than the thickness of the outer plate 13, it is conceivable that the amount of heat input required for securing the welding strength becomes excessive only by laser welding. Therefore, the welding strength of the entrance frame 12 and the outer plate 13 is sufficiently ensured by the spot welding portion W1, and the laser welding for securing water tightness is combined with the laser welding to suppress the heat input to the work during the laser welding. Can be.

  In the present embodiment, in the welding process, a laser beam is emitted from the laser welding machine 1 to form a laser weld W2. The conditions for laser welding are, for example, pulse width of 10 ms to 30 ms, frequency of 10 Hz to 30 Hz, and heat input of about 10 J to 30 J. The laser weld W2 may be formed by overlapping individual nuggets. In the processing step, a CW laser is emitted from the laser welding machine 1 to perform chamfering. The output of the CW laser in this case is, for example, about 200 W to 250 W.

  As described above, in this laser welding method, the vehicle outer side surface 14a of the entrance frame 12 and the end surface 16a of the outer plate 13 are fillet-welded by the laser using the hand torch type laser welding machine 1. By forming the continuous laser welded portion W2 on the vehicle outer side surface 14a of the entrance frame 12 and the end surface 16a of the outer plate 13 by laser welding, it is possible to sufficiently secure the watertightness of the joined body 11. Further, in this laser welding method, by using the hand torch type laser welding machine 1, unlike the case of automatic welding, a complicated teaching operation for ensuring the followability of laser light is not required, and the welding operation is performed. Performance can be improved.

  In the present embodiment, in performing the laser welding by grasping the torch part 4 and performing the manual laser welding in the welding process, the first surface 23 of the first contact tip 7A applied to the torch part 4 is outside the vehicle of the entrance frame 12. The second surface 24 is in contact with the side surface 14 a and the end surface 16 a of the outer plate 13. For this reason, the vehicle outer side surface 14a of the entrance frame 12 and the end surface 16a of the outer plate 13 serve as guides, and it is possible to prevent the hand from gripping the torch 4. Therefore, it is possible to prevent the laser light from being damaged.

  In the present embodiment, in the welding step, a laser beam is radiated from the laser welding machine 1 to form a laser welding portion W2. When the CW laser is used in the welding process, if the scanning of the torch part 4 is stopped during the welding, a hole may be opened in the work at the stopped position. On the other hand, when the pulse laser is used, even if the scanning of the torch portion 4 is stopped during welding, a hole is prevented from being opened in the work at the stopped position, and laser welding can be resumed from that position. Therefore, the workability of welding can be further improved.

  Further, in the present embodiment, in the processing step, the first surface 33 of the second contact chip 7B applied to the torch portion 4 is in contact with the vehicle outer surface 16c of the outer plate 13 and the second surface 34 is The third surface 37 is in contact with the end surface 16 a and the vehicle outer surface 14 a of the entrance frame 12. For this reason, the vehicle outer side surface 14a of the entrance frame 12, the end surface 16a of the outer plate 13, and the vehicle outer side surface 16c serve as guides, and it is possible to prevent the hand from gripping the torch portion 4. The third surface 37 of the second contact chip 7B does not necessarily have to be in contact with the vehicle outer surface 14a of the entrance frame 12. Even in this case, since the first surface 33 contacts the vehicle outer surface 16c of the outer plate 13 and the second surface 34 contacts the end surface 16a of the outer plate 13, the guide function of the second contact chip 7B is sufficiently performed. You.

  Further, in the present embodiment, an R-shaped notch 26 is formed at a corner 25 formed by the first surface 23 and the second surface 24 in the first contact chip 7A. Similarly, in the second contact chip 7B, an R-shaped notch 36 is formed at a corner 35 formed by the first surface 33 and the second surface 34. Due to the formation of the notches 26 and 36, even when burrs or the like exist on the end surface 16a (particularly at the corner) of the outer plate 13, the first contact chip 7A and the second contact chip 7A are formed by the notches 26 and 36. By avoiding the collision of the burr with the contact chip 7B, the scanning of the torch part 4 can be preferably performed manually.

  In the present embodiment, the first contact chip 7A and the second contact chip 7B are formed of a conductive material. Thereby, for example, by attaching the ground to the work, the interlock function of the laser welding machine 1 according to the presence or absence of energization can be realized. Thereby, the safety of the laser welding operation can be improved. Further, by selecting a conductive material having a hardness lower than that of the work, generation of scratches on the work is also suppressed.

  The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the entrance frame 12 is illustrated as the first work, but the first work may be another frame member that holds the opening in the railway vehicle structure. Examples of such a frame member include a window frame and a hood frame. Further, the second work is not limited to the outer plate. The present invention is widely applicable to fillet welding between a first work and a second work. Further, the present invention is also applicable to a work used for a railway vehicle structure made of an aluminum alloy, a work of a railway vehicle structure made of a magnesium alloy, and the like.

  Further, in the above embodiment, the convex portion 21 and the concave portion 31 are designed such that the first contact chip 7A and the second contact chip 7B are inclined by 45 ° with respect to the entrance frame 12 and the outer plate 13. However, the convex portion 21 and the concave portion 31 may be designed in a range where the inclination angle is 45 ° to 75 °. Regardless of the inclination angle, the first contact tip 7A and the second contact tip 7B are preferably attached coaxially to the torch part 4.

  DESCRIPTION OF SYMBOLS 1 ... Laser welding machine, 4 ... Torch part, 7A ... 1st contact tip, 7B ... 2nd contact tip, 12 ... Doorway frame (1st work), 13 ... Outer plate (2nd work), 14a ... Vehicle outer surface (principal surface), 16 ... end, 16a ... end surface, 16b ... corner, 16c ... vehicle outer surface (principal surface), 21 ... convex, 23 ... first surface, 24 ... second surface , 25 ... corner portion, 26 ... notch portion, 31 ... concave portion, 33 ... first surface, 34 ... second surface, 35 ... corner portion, 36 ... notch portion, 37 ... third surface, P ... overlapping portion, W2: laser welded part.

Claims (13)

An arranging step of superposing the end of the second work on the main surface of the first work;
Welding using a hand torch type laser welding machine to form a continuous laser weld along the overlapping portion between the main surface of the first work and the end surface on the end side of the second work. And a process,
In the welding step, the first contact tip having a convex portion formed by a first surface in contact with the main surface of the first work and a second surface in contact with the end surface of the second work is formed by the method described above. Laser welding of the main surface and the end surface by applying to the torch portion of a laser welding machine,
The laser welding method, wherein the first contact tip further includes a cutout at a corner formed by the first surface and the second surface.   The laser welding method according to claim 1, wherein the first contact tip is formed of a conductive material. A machining step of chamfering an end of the second work;
In the processing step, a second contact chip having a concave portion formed by a first surface in contact with a main surface of the second work and a second surface in contact with the end surface of the second work is subjected to the laser welding. 3. The laser welding method according to claim 1, wherein the edge is chamfered by applying to a torch portion of the machine.   4. The laser welding method according to claim 3, wherein the second contact tip further has a third surface that is in contact with a main surface of the first work.   5. The laser welding method according to claim 3, wherein the second contact tip further includes a notch at a corner formed by the first surface and the second surface. 6.   The laser welding method according to claim 3, wherein the second contact tip is formed of a conductive material.   The laser welding method according to any one of claims 1 to 6, wherein in the welding step, the laser welder is formed by irradiating a pulse laser from the laser welder. The first work is a frame member that holds an opening in the railway vehicle structure, and the second work is an outer plate in the railway vehicle structure,
The laser welding method according to any one of claims 1 to 7, wherein, in the disposing step, the outer plate is overlapped on a vehicle outer side surface of the frame member. A hand torch type laser welding machine for forming a continuous laser weld along an overlapping portion between a main surface of a first work and an end of a second work,
A detachable first contact chip having a convex portion formed by a first surface in contact with the main surface of the first work and a second surface in contact with the end surface on the end side of the second work. Comprising a torch part having
A laser welding machine, wherein a cutout is further formed at a corner formed by the first surface and the second surface in the first contact tip.   The laser welding machine according to claim 9, wherein the first contact tip is formed of a conductive material. The torch portion includes a detachable second contact chip having a concave portion formed by a first surface in contact with a main surface of the second work and a second surface in contact with the end surface of the second work. Have
The laser welding machine according to claim 9, wherein the second contact tip further has a third surface in contact with a main surface of the first work . The laser welding machine according to claim 11, wherein the second contact tip further includes a notch at a corner formed by the first surface and the second surface. The second contact tip, laser welding machine according to claim 11 or 12, wherein is formed by a conductive material.

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