JP2007000909A - Laser beam welding equipment and laser beam welding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the welding quality by properly securing a space between two plate materials when laser-beam-welding a workpiece with a lap-joint of the two plate materials. <P>SOLUTION: A space S is formed between two plate materials Wu, Wd, which are made of a galvanized steel plate, by a projecting part 5 formed on the plate material Wu, which is placed in the upper side. The workpiece W that is in the side orthogonal to the weld advancing direction in the vicinity of the projecting part 5 is pressurized by a pressure roller 11 so that the two plate materials Wu, Wd come into contact with each other. In such a pressurized state, the workpiece is pressurized by a pressure pin 15 in the direction such that the two plate materials Wu, Wd come into contact with each other in the state that the space S is secured in the vicinity of a laser beam irradiation portion 7 between the pressure roller 11 and the projecting part 5. The pressure pin 15 is positioned in the front side of the laser beam irradiation portion 7 in the weld advancing direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laser welding apparatus and a laser welding method for performing laser welding on a workpiece surface-treated with a coating layer that generates gas by heating using a lap joint of two plate members.

  Welding by local heating, such as laser welding, is used for butt welding, lap welding, and the like as a welding method with less welding distortion of the workpiece because there is little heat input to the workpiece. The reason for the low heat input is that energy can be concentrated by collecting local heating sources such as laser beams at small points, and welding can be performed at high speed.

  In such laser welding, only the energy heat input portion of the workpiece is melted and joined, so that the amount of workpiece melting is small and the joint gap needs to be small.

  Also, when laser welding galvanized steel sheets, especially during lap welding, the galvanized layer on the workpiece surface evaporates and scatters, resulting in weld defects (blow holes and bubbles). It is necessary to provide an appropriate gap on the workpiece, and in order to provide this gap, it is generally performed to provide a protrusion on the workpiece.

For example, the one disclosed in Patent Document 1 below provides a plated steel plate by providing a protruding portion that protrudes toward the lower plate on the upper plate of two stacked plated steel plates, and bringing the protruding portion into contact with the lower plate. A gap is formed between them. At this time, the upper plate in the vicinity of the protruding portion is pressed against the lower plate by a jig so as to ensure a gap corresponding to the height of the protruding portion.
JP 2001-162388 A

  However, in the conventional technology described above, the gap changes depending on the positional relationship between the protruding portion, the pressurizing portion, and the welded portion, and the height of the protruding portion. Therefore, it is necessary to manage these accurately. For this reason, it is difficult to appropriately secure the gap, and the change in the gap causes the weld bead shape to become unstable, resulting in a decrease in welding quality.

  Therefore, the present invention has an object to appropriately secure a gap between plate materials when laser welding is performed on a workpiece with a lap joint of two plate materials to improve welding quality.

  The present invention provides a laser welding apparatus for performing laser welding on a workpiece, which has been surface-treated with a coating layer that generates gas by heating, with a lap joint of two plate members, in order to form a gap between the two plate members. And a first pressurizing part that pressurizes the two plate members in contact with each other between the first pressurizing part and the gap securing part. And pressurizing in the direction in which the two sheets of materials are in contact with each other in a state where the gap is secured with respect to the vicinity of the laser beam irradiation site having a gap between the two sheets of the sheet, and against the first pressure member The most important feature is that a second pressurizing unit is provided at a position shifted by a specified dimension in the pressurizing direction.

  According to the present invention, in the vicinity of the laser light irradiation site between the gap securing portion and the first pressurizing portion that pressurizes the two plate materials so that the two plate materials are brought into contact with each other, the second pressurizing portion causes the two plate materials to be mutually connected. Since the gap was secured by pressing in the contact direction, even if the positional relationship between the gap securing part, the first pressure part and the laser light irradiation site and the dimensions of the gap securing part have changed somewhat, By pressurization by the second pressurizing unit located at a position shifted by a specified dimension in the pressurizing direction with respect to the first pressurizing unit, a gap at the laser light irradiation site can be appropriately secured and the welding quality is improved. Can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view of a laser welding apparatus showing a first embodiment of the present invention, and FIG. 2 is a front view of a main part viewed from the direction of arrow A in FIG. The work W here is a superposition of two plate materials Wu, Wd, which are galvanized steel plates that generate gas by heating, for example, zinc is plated as a surface treatment. The two plate materials Wu, Lap joint welding is performed on Wd by the laser beam 3 emitted from the laser processing head 1.

  In this case, the plate member Wu located at the upper portion is provided with a protruding portion 5 as a gap securing portion formed by, for example, embossing so as to protrude toward the lower plate member Wd. The laser beam 3 is irradiated in the vicinity of the right side in this, and this is set as a laser irradiation portion 7.

  As a laser oscillator provided at the other end of the optical fiber 5 having one end connected to the laser processing head 1, for example, a YAG laser is used, and laser processing is performed in the right direction indicated by an arrow B in FIG. 1 (the front side in FIG. 2). Welding is performed while the head 1 moves.

  As shown in FIG. 2, a roller holding block 9 is attached to the lower side surface of the laser processing head 1, and the upper portion of the roller holding bracket 10 is attached to the tip of the roller holding block 9. A pressure roller 11 constituting a first pressure unit is rotatably attached to the lower side surface of the roller holding bracket 10 via a support shaft 13.

  The pressure roller 11 is located on the opposite side of the projecting portion 5 with respect to the laser irradiation portion 7. The upper plate material Wu is pressed against the workpiece W at this position, and the pressed plate material Wu is placed on the lower side. The plate material Wd is brought into contact. Thereby, a gap S having a substantially triangular shape in FIG. 2 is formed between the plate members Wu and Wd between the protrusion 5 and the pressure roller 11.

  Moreover, the upper part of the pressure pin 15 used as a 2nd pressurization part is attached to the front side of the welding progress direction (arrow B direction in FIG. 1) in the lower part of the laser processing head 1, and the lower part of the pressurization pin 15 is As shown in FIG. 1, it is bent toward the laser beam 3 side, and the upper plate member Wu is pressurized by its lower end as shown in FIG. As shown in FIG. 1, the pressing position of the pressing pin 15 to the plate material Wu is positioned in front of the welding direction B with respect to the laser irradiation portion 7 by the laser beam 3 and on the same straight line in the welding direction. ing.

  The lower end of the pressure pin 15 is installed at a position shifted by a specified dimension, for example, h = 0.2 to 0.3 mm above the lower end of the pressure roller 11 for applying pressure so that the plate materials Wu and Wd are brought into close contact with each other. At the time of pressurization by the pressure pin 15, the gap between the plate material Wu and the plate material Wd is made appropriate.

  The laser processing head 1 described above is held by the laser welding robot 19 and moves in the welding progress direction B described above. The laser welding robot 19 includes a head holding bracket 21. The head holding bracket 21 includes a cylinder mounting portion 25 that extends in the vertical direction in FIG. 1 at the tip of the base portion 23, and a guide mounting portion 27 that protrudes rightward in FIG. 1 at the upper end of the cylinder mounting portion 25. It has. An air cylinder 29 that moves the laser processing head 1 up and down is mounted on the cylinder mounting portion 25, and an upper portion of a guide rail 31 that guides the vertical movement of the laser processing head 1 is mounted on the guide mounting portion 27.

  On the other hand, a head holder 33 is attached to the laser processing head 1. The head holder 33 includes a fixing portion 35 fixed to the laser processing head 1, a connecting portion 39 to which the tip of the piston rod 37 of the air cylinder 29 is connected and fixed, and a slide portion 41 that moves up and down along the guide rail 31. And each.

  Further, a nozzle 43 that discharges argon gas serving as a shielding gas for protecting the welded portion is attached to the laser processing head 1 or the head holder 33 via a bracket (not shown). The nozzle 43 is supplied with argon gas through a gas pipe from an argon gas cylinder (not shown). Further, although not particularly shown, a mechanism for releasing air serving as an air shutter for protecting the laser irradiation port from welding fumes and spatters is provided.

  The pressurization part of the work W by the pressure roller 11 is perpendicular to the welding progress direction B with respect to the laser irradiation part 7 in FIG. In FIG. 2, it may be in any position within the range of P (FIG. 1) between the right side position.

  FIG. 3 shows a state in which the laser beam 3 is applied to the workpiece W while the workpiece W is being pressed by the pressure roller 11 and the pressure pin 15 and the laser processing head 1 is moved in the welding progress direction B. It is the perspective view which simplified and showed the state which is performing laser welding.

  Next, the operation will be described. First, as shown in FIG. 4A, the plate material Wu including the protrusions 5 is placed on the plate material Wd. At this time, due to the occurrence of bending or the like of each plate material Wu, Wd, the projection 5 does not entirely contact the plate material Wd, but is a portion separated from the plate material Wd as shown in FIG. There is.

  In this state, the laser welding head 19 moves the laser processing head 1 to a position above the processing portion of the workpiece W, and then the piston rod 37 moves downward in FIG. Thus, the laser processing head 1 moves downward via the head holder 33.

  As a result, as shown in FIG. 4B, the pressure roller 11 contacts the plate material Wu at a position spaced apart from the projection 5 by a predetermined distance, and the projection 5 in the vicinity thereof is separated from the plate Wd. The part in contact with the plate material Wd. At this time, the pressure pin 15 is not yet in contact with the plate material Wu.

  Thereafter, by further lowering the laser processing head 1 by driving the air cylinder 29, the plate material Wu starts to deform as shown in FIG. 4C, and the pressurizing pin 15 also comes into contact with the plate material Wu and pressurizes accordingly. . Subsequently, as shown in FIG. 4D, the plate material Wu comes into contact with the plate material Wd at the portion pressed by the pressure roller 11, and in this state, the pressure on the workpiece W is completed.

  As shown in FIG. 4D, in a state in which the pressure roller 11 is pressed until the plate material Wu is brought into contact with the plate material Wd, the pressure pin 15 has the lower surface of the plate material Wu and the plate material at a position below the pressure portion. Pressurization is performed so that a gap t formed between the upper surface of Wd and the upper surface of Wd is an appropriate value when performing lap welding of the plate materials Wu and Wd of the galvanized steel plate.

  The appropriate value of the above-described gap dimension t is equal to or greater than the minimum allowable value that allows the gas of the galvanized layer generated by heating at the time of laser beam 3 irradiation to escape. Such a gap dimension t can be easily formed by setting the lower end of the pressure pin 15 to a position shifted upward from the lower end of the pressure roller 11 by the specified dimension h.

  Laser welding is performed by moving the laser processing head 1 in the welding progress direction B as shown in FIG. 3 in accordance with the teaching operation of the laser welding robot 19 in a pressurized state on the workpiece W described above. At this time, the pressure roller 11 moves while rotating with respect to the plate material Wu, and the pressure pin 15 moves while being in contact with the plate material Wu.

  When performing laser welding as described above, the pressure pin 15 pressurizes the vicinity of the laser irradiation portion 7 between the pressure roller 11 and the protrusion 5 that are in contact with each other of the plate materials Wu and Wd. The gap dimension t between the plate materials Wu and Wd in the vicinity of the laser irradiation site 7 is appropriately secured.

  At this time, in this embodiment, the pressure roller 11 and the pressure pin 15 are not affected even if the positional relationship between the protrusion 5, the pressure roller 11 and the laser irradiation site 7 or the height of the protrusion 5 slightly changes. Since the vertical position is shifted by the specified dimension h, the above-described gap dimension t can be kept constant.

  Therefore, the gap dimension t can be appropriately secured without accurately managing the positional relationship between the protrusions 5, the pressure roller 11 and the laser irradiation portion 7 and the height of the protrusions 5. Even if the galvanized layer on the surface of the workpiece W evaporates and scatters, the occurrence of welding defects (blow holes and air bubbles) is prevented, thereby stabilizing the weld bead shape and improving the welding quality.

  FIGS. 5A to 5C show an example in which the mutual positional relationship between the protrusion 5, the pressure roller 11, and the laser irradiation portion 7, and the height of the protrusion 5 are changed.

  FIG. 5B shows an example in which the distance C between the protrusion 5 and the pressure pin 15 is wider than the same distance D in FIG. In this example, the laser processing head 1 is located farther from the protrusion 5 with respect to FIG. 5A, and at this time, the pressure roller 11 and the pressure pin 15 are integrated with the laser processing head 1. Therefore, the difference in height between the two (specified dimension h) and the distance E in the left-right direction in the figure are the same in FIGS. 5 (a) and 5 (b).

  Further, since the plate members Wu and Wd are in close contact with each other at the portion pressed by the pressure roller 11, the distance between the pressure roller 11 and the upper surface of the lower plate member Wd is equal to the plate thickness of the upper plate member Wu. 5 (a) and 5 (b), the distance between the pressure pin 15 and the plate material Wd is also constant, and the gap dimension between the lower surface of the plate material Wu corresponding to the pressure pin 15 and the upper surface of the plate material Wd. Although t is slightly different depending on the difference in the inclination angle of the plate material Wu, it is substantially the same in FIGS. 5A and 5B.

  As described above, even when the distances D and C between the protrusion 5 and the pressure pin 15 change as shown in FIGS. 5A and 5B, the gap t in the vicinity of the laser irradiation site 7 is kept constant. be able to.

  FIG.5 (c) is an example in which the height F of the projection part 5 is higher than the same height G of Fig.5 (a). In this example, the relative positional relationship between the laser processing head 1 and the workpiece W is the same in FIGS. 5A and 5C, and the pressure roller 11 and the pressure pin 15 are integrated with the laser processing head 1. Therefore, as in the above, the difference in height between the two (specified dimension h) and the distance E in the left-right direction in the figure are the same in FIGS. 5 (a) and 5 (c). Note that the applied pressure is increased as the height F of the protrusion 5 increases.

  Accordingly, in this example as well, the plate materials Wu and Wd are in close contact with each other at the portion pressed by the pressure roller 11, so that the distance between the pressure roller 11 and the upper surface of the lower plate material Wd is equal to the plate thickness of the plate material Wu. 5 (a) and 5 (c), the distance between the pressure pin 15 and the plate material Wd is also the same in FIGS. 5 (a) and 5 (c), and the lower surface of the plate material Wu and the plate material Wd. The gap dimension t with the upper surface of FIG. 5 is also substantially the same in FIGS. 5A and 5C, although it slightly differs depending on the difference in the inclination angle of the plate material Wu.

  As described above, even when the heights G and F of the protrusions 5 are changed as shown in FIGS. 5A and 5C, the gap dimension t in the vicinity of the laser irradiation site 7 can be kept constant.

  In the above-described embodiment, the positional relationship between the protrusion 5, the pressure roller 11 and the laser irradiation site 7 and the allowable value of the change in the height of the protrusion 5 are set to the conventional example in which the pressure pin 15 is not provided. On the other hand, it can be made large with an appropriate gap dimension t secured.

  In addition, regarding the control of the applied pressure, the allowable value can be made larger than in the past, and the gap between the protrusion 5 and the lower plate material Wd that may occur in the state of FIG. The allowable value can be increased as compared with the prior art.

  Furthermore, in this embodiment, the following effects can be obtained.

  Since the pressure roller 11 and the pressure pin 15 are pressed from above the one side of the workpiece W, the gap dimension t is properly secured not only in the vicinity of the end of the workpiece W but also in laser welding to a portion away from the end. However, it can be implemented.

  Even when the plate thickness changes due to press working or the like, the difference in height between the pressure roller 11 and the pressure pin 15 (specified dimension h) is constant, so that the gap dimension t can be ensured appropriately.

  In the present embodiment, it is necessary to manage the difference in height (specified dimension h) between the pressure roller 11 and the pressure pin 15 to a specified value. As shown in FIG. 1, since it is integrated with the laser processing head 1, it can be easily managed by ensuring the accuracy during installation (or equipment maintenance, work inspection, etc.), and the gap size. t can be easily secured.

  As the pressure applied to the workpiece W, the total value of the pressure applied to the pressure roller 11 and the pressure pin 15 may be managed.

  Since the pressure roller 11 and the pressure pin 15 are located in the vicinity of the laser irradiation portion 7 during welding work and the relative positions thereof are constant, the pressure roller 11 or the pressure pin 15 is connected to the pressure roller 11 or the pressure pin 15. The function of the nozzle 43 that discharges the argon gas may be provided.

  The pressure roller 11 may be a pin that slides like the pressure pin 15 without rotating on the workpiece W. Conversely, the pressure pin 15 does not slide on the workpiece W. Alternatively, a rotating roller such as the pressure roller 11 may be used.

  Further, instead of the protrusions 5 continuing in the welding progress direction B as shown in FIG. 3, a plurality of circular protrusions may be provided intermittently at predetermined intervals along the welding progress direction B.

  Further, instead of the above-described protrusion 5 as the gap securing portion, as shown in FIG. 6A, a method of inserting the different material 45 between the two plate members Wu and Wd to secure the gap S, or FIG. A method of securing the gap S by providing a bent portion 47 that bends upward on the upper plate member Wu as shown in FIG.

  In addition, you may provide the above-mentioned projection part 5 for forming the clearance gap between board | plate materials Wu and Wd in the lower board | plate material Wd.

  However, if the rigidity of the two plate members Wu and Wd is different, it is easier to press the upper plate member Wu to be pressed with a lower rigidity, and therefore the upper plate member that is easier to press, that is, the lower rigidity. Since the formability is better when the plate material is embossed, it is better to provide the protrusions 5 on the upper plate material when the two plate materials Wu and Wd have different rigidity.

  Further, when the protrusions 5 are provided on the upper plate member Wu, the positional relationship between the protrusions 5 and the welded parts can be confirmed from the upper side to be welded, so that the welding operation itself and quality confirmation after welding are easy.

  FIG. 7 shows that the distance between the protrusion 5 and the pressure roller 11 is H, the distance between the pressure roller 11 and the pressure pin 15 is E, the height equivalent dimension of the protrusion 5 is t 0, and the gap between the pressure pins 15. The relationship between values is shown where the dimension is t and the height dimension difference between the pressure roller 11 and the pressure pin 15 is h.

  In such a positional relationship between values, the height of the protrusion 5 is set so that t0 / H> h / E, that is, t0> (H / E) × h. If this equation does not hold, the height of the protrusion 5 (the height equivalent dimension t0 of the protrusion 5) will be too low, and the gap dimension t will also be smaller than the appropriate value.

  In this way, by managing the height of the protrusion 5 with the minimum value, management becomes easier as compared with the case of managing with a certain width.

  As a second embodiment of the present invention, the load generated by the pressure of the pressure roller 11 is measured, and the entire pressure roller 11 and the pressure pin 15 are combined with the workpiece W according to the measured load. Adjust the pressure. As a result, deformation of the workpiece W (lower plate material Wd) due to excessive pressure is prevented, and deformation of the gap between the plate materials Wu and Wd is prevented, and the gap dimension t is made appropriate. Moreover, the energy required for pressurization can be minimized.

  In addition, by recording the change in the required pressure, it is possible to monitor the change in accuracy of the protrusion 5 and the change in accuracy of alignment between the plate members Wu and Wd.

For example, in FIGS. 5A to 5C, the total pressure is changed so that the load applied by the pressure roller 11 is constant. Table 1 shows the applied pressure at that time.

  In a state where the load by the pressure roller 11 is constant 100N, the load by the pressure pin 15 is 200N in FIG. 5A, 100N in FIG. 5B, and 300N in FIG. 5C. The total pressure is 300 N in FIG. 5A, 200 N in FIG. 5B, and 400 N in FIG. 5C. That is, in this case, the pressure pin 15 increases the pressure applied to the two plate members Wu and Wd as the pressure pin 15 is closer to the protrusion 5 and the height of the protrusion 5 is larger. is doing.

  In this way, by making the load at the portion where the plate materials Wu and Wd are in close contact with each other and being pressed constant, deformation of the lower plate material Wd can be prevented, and the gap t at the welded portion can be appropriately secured. Can do.

On the other hand, Table 2 shows the load applied by the pressure roller 11 and the pressure pin 15 when the total pressure is constant 400 N in all of FIGS. In this case, the load on the pressure roller 11 changes in FIGS. 5A to 5C, and as a result, the lower plate member Wd is deformed in FIG. 5B where the load is 300 N, for example. As a result, the gap dimension t at the welded portion cannot be properly secured.

  FIG. 8 is a front view corresponding to FIG. 4B, according to the third embodiment of the present invention. In this embodiment, the lower plate material Wd is received on the opposite side of the pressure roller 11 with the two plate materials Wu and Wd interposed therebetween, and the two plate materials Wu and Wd are received between the pressure roller 11. A roller side receiving jig 49 is provided as a work receiving portion for holding the sheet, and a lower side is provided at a portion corresponding to the protruding portion 5 on the opposite side of the pressure roller 11 with the two plate members Wu and Wd interposed therebetween. A protrusion side receiving jig 51 is provided as a work receiving portion for receiving the plate material Wd.

  As a result, the rigidity of the plate material Wd is particularly low, and the deformation of the plate material Wd can be prevented when the applied pressure is increased in order to correct the alignment variation between the two plate materials Wu and Wd. t can be secured with high accuracy.

  Instead of the roller side receiving jig 49 and the protrusion side receiving jig 51 described above, a reinforcing material may be provided on the plate material Wd itself to increase strength and prevent deformation.

  FIG. 9 is a perspective view corresponding to FIG. 3 according to the fourth embodiment of the present invention. In this embodiment, two pressure pins 53 and 55 are used instead of the single pressure pin 15 in the first embodiment, and two locations on both sides in the welding progress direction B with respect to the laser beam irradiation site 7. It is set as the structure which pressurizes. Here, it is assumed that the two pressing positions by the two pressing pins 53 and 55 are equidistant from the laser beam irradiation site 7.

  As shown in FIGS. 10A and 10B, the two pressure pins 53 and 55 are connected to a support shaft 57 provided in the laser processing head 1 similar to that shown in FIG. 59 is supported. The link mechanism 59 extends laterally with respect to the support shaft 57 and can be pivoted up and down, and the upper end of the horizontal link 61 is rotatably connected to both ends of the horizontal link 61. A pair of vertical links 63 and 65 connected to 55 are provided.

  That is, as shown in FIG. 10A, the two pressing pins 53 and 55 that are at the same height are pressed against the upper plate member Wu by the pressing operation of the pressing roller 11. As a result, the link mechanism 59 rotates in the clockwise direction in FIG. 10 along the inclination of the plate material Wu. At this time, the average value of the vertical heights of the two pressure pins 53, 55 is the vertical height of the intermediate position between the pins 53, 55, that is, the vertical height of the pressure pin 15 in the first embodiment. As a result, the height difference (specified dimension h) between the pressure roller 11 and the two pressure pins 53 and 55 can be ensured similarly to the first embodiment.

  In this way, by pressing the two portions on both sides of the laser irradiation portion 7 with the two pressing pins 53 and 55, the pressing portion becomes the same position in the welding progress direction with respect to the laser irradiation portion 7, so that the first Compared with the case where the pressurization site by the pressurization pin 15 is ahead of the laser irradiation site 7 in the welding direction as in the embodiment, the gap dimension t can be made more appropriate.

  In the fourth embodiment described above, the difference in height between the two pressure pins 53 and 55 is detected by a pressure portion position detection means (not shown), and the detected difference deviates from the specified value. In such a case, the abnormality determination means determines the displacement of the welding position or the abnormality of the protrusion 5 and performs a process of stopping the welding operation.

  FIG. 11 is a schematic plan view of a laser welding apparatus according to the fifth embodiment of the present invention. In this embodiment, the pressure roller 11 and the pressure pin 15 are integrally rotated around the laser irradiation portion 7 as a welding point with respect to the laser processing head 1 in the first embodiment shown in FIG. It is configured as possible.

  In this case, as shown in FIG. 11 (a), the laser processing head 1 moves from the top to the bottom in the drawing and laser welding is performed, and as shown in FIG. When laser welding is continuously performed while the laser processing head 1 moves, the pressure roller 11 and the pressure pin 15 are integrated with each other at a direction change point 67 where the welding progress direction changes from B to Ba. In this state, it is rotated 90 degrees clockwise in FIG. At this time, it is not necessary to change the posture of the laser welding robot 19 as it is. In addition, what is shown with the code | symbol 69 in FIG. 11 is a weld bead.

  As specific means for integrally rotating the pressure roller 11 and the pressure pin 15, a motor and a member that is rotated by the motor are attached to the laser processing head 1 and the head holder 33 in FIG. 1. The pressure roller 11 and the pressure pin 15 may be fixed and held on this rotating member.

  In each of the embodiments described above, the example in which the workpiece W is pressed downward has been described. However, the present invention is also applied to the case where the workpiece is erected in the horizontal direction. Can do.

  FIG. 12 is a side view corresponding to FIG. 1 of a laser welding apparatus showing a sixth embodiment of the present invention, and FIG. 13 is a front view of the laser welding apparatus viewed from the right direction in FIG. It is. In this embodiment, an upper jig 71 separate from the laser processing head 1 is pressed downward as the first pressurizing unit against the upper plate member Wu. A lower jig 73 is provided below the lower plate material Wd, and the workpiece W is sandwiched between these jigs 71 and 73. In FIG. 12, the upper jig 71, the lower jig 73, and the upper plate member Wu are omitted.

  The laser processing head 1 here includes a horizontal movable pedestal 75 mounted on the left side in FIG. 12, and slides together with the horizontal movable pedestal 75 along a horizontal slide rail 77 extending in the left-right direction in FIG. A piston rod 81 of a horizontal drive air cylinder 79 is connected to the horizontal movable pedestal 75, and the laser machining head 1 moves in the left-right direction in FIG.

  The horizontal slide rail 77 and the horizontal drive air cylinder 79 are fixed to the lower side surface of the vertical movable pedestal 83, and the vertical movable pedestal 83 moves along the vertical slide rail 85 extending vertically in FIGS. A piston rod 88 of an up / down drive air cylinder 87 is connected to the upper end of the up / down moveable pedestal 83, and the up / down moveable pedestal 83 is moved in the up / down direction in FIGS. To do.

  The vertical slide rail 85 and the vertical drive air cylinder 87 are fixedly held by a head holding bracket 89 provided in the laser welding robot 19.

  The laser processing head 1 is provided with a pressure pin 15 as in the first embodiment shown in FIG. Further, as shown in FIG. 13, the laser processing head 1 has a positioning mechanism 91 as position defining means for defining the relative positional relationship with the upper jig 71 at the position where the roller holding block 9 in FIG. Wearing.

  The positioning mechanism 91 includes a horizontal member 93 that extends in the horizontal direction from the laser processing head 1 toward the upper jig 71, and a vertical member 95 that extends downward from the middle of the horizontal member 93. Then, a hemispherical vertical positioning projection 97 is provided as a contact portion at the lower end of the horizontal member 93, and the same hemispherical horizontal positioning projection 99 is provided as a contact portion at the front end side of the vertical member 95. It is provided facing the jig 71.

  Next, the operation of the sixth embodiment shown in FIGS. 12 and 13 will be described. The workpiece W is sandwiched and pressed between the upper and lower jigs 71 and the lower jig 73, and the laser processing head 1 is moved to a position corresponding to FIG. At this time, the horizontal drive air cylinder 79 and the vertical drive air cylinder 87 both advance the piston rods 81 and 88 to the forward limit position.

  Then, from the state of FIG. 13, the laser processing head 1 is moved rightward in FIG. 13 by the teaching operation of the laser welding robot 19, and the horizontal positioning protrusion 99 is brought into contact with the side surface of the upper jig 71. And push further. As a result, the piston rod 81 moves backward and stops at the backward limit position. At the retreat limit position of the piston rod 81, the horizontal interval between the upper jig 71 as the first pressure member and the pressure pin 15 is the pressure roller in the first embodiment shown in FIG. 11 and the same distance between the pressure pins 15.

  Subsequently, by the teaching operation of the laser welding robot 19, the laser processing head 1 is moved downward in FIG. 13 so that the vertical positioning protrusion 97 is brought into contact with the upper surface of the upper jig 71 and further pushed. As a result, the piston rod 88 moves backward and stops at the backward limit position. At the retreat limit position of the piston rod 88, the vertical (height) direction interval between the upper jig 71, which is the first pressurizing portion, and the pressurizing pin 15 is adjusted in the first embodiment shown in FIG. This is equivalent to the same distance (specified dimension h) between the pressure roller 11 and the pressure pin 15.

  Thus, in the state where the pressure pin 15 is positioned relative to the upper jig 71, as shown in the schematic diagram of FIG. 14 with respect to FIG. The gap t is secured.

  According to the above-described sixth embodiment, the upper jig 71 clamps and fixes the workpiece W between the lower jig 73 before welding, and the plate material Wu and the plate material Wd are brought into close contact with each other. The position shift of the workpiece W due to the pressurization of the processing head 1 can be prevented. In addition, since the first pressurizing portion is the upper jig 71 and separate from the laser processing head 1, the structure on the laser processing head 1 side can be simplified.

  Furthermore, the correction of the alignment state between the two plate materials Wu and Wd is performed by the upper jig 71, and it is not necessary to perform the pressurization with the pressurization pin 15. Therefore, the pressurization force of the pressurization pin 15 is applied in the first embodiment. It can be made weaker than the form, and deformation of the upper plate material Wu can be suppressed.

  Further, since the laser processing head 1 is positioned by the positioning mechanism 91 with respect to the upper jig 71 holding the workpiece W, the posture of the laser processing head 1 with respect to the workpiece W is stabilized, and as a result, the gap dimension t Even stable welding quality is improved.

  FIG. 15 is a schematic view corresponding to FIG. 14 of a laser welding apparatus showing a seventh embodiment of the present invention. In this embodiment, a positioning mechanism 101 is provided instead of the positioning mechanism 91 in FIG.

  The positioning mechanism 101 includes an upper / lower position sensor unit 103 as position detecting means for detecting the upper surface position of the upper jig 71, and left and right as position detecting means for detecting the left side surface position of the upper jig 71 in FIG. 15. A position sensor unit 105 is provided.

  In this embodiment, the laser machining head 1 is moved by the teaching operation of the laser welding robot 19 so that the pressure pin 15 is substantially at the same position as the pressure pin 15 in FIG. The laser processing head 1 is moved rightward in FIG. 15 by the teaching operation of the laser welding robot 19, and the detection operation of the upper jig 71 by the left and right position sensor unit 105 is first performed.

  When the left / right position sensor unit 105 detects the upper jig 71, the laser processing head 1 stops moving in the right direction in FIG. 15, and this time, by the teaching operation of the laser welding robot 19, the laser processing head 1. 15 is moved downward in FIG. 15, and the detection operation of the upper jig 71 by the vertical position sensor unit 103 is performed. When the vertical position sensor 103 detects the upper jig 71, the laser processing head 1 stops moving downward in FIG.

  In this state, the relative position of the laser processing head 1 with respect to the upper jig 71 is defined, and at this time, the pressure pin 15 is located on the upper side so as to ensure the above-described defined gap dimension t between the two plate materials Wu and Wd. The plate material Wu is pressurized.

  According to the seventh embodiment described above, the same effects as those of the sixth embodiment shown in FIGS. 12 to 14 can be obtained. Further, according to the seventh embodiment, the structure can be simplified because the slide mechanism for sliding the positioning mechanism 91 together with the laser processing head 1 as in the sixth embodiment is unnecessary.

  FIG. 16 is a schematic view corresponding to FIG. 14 of a laser welding apparatus showing an eighth embodiment of the present invention. In this embodiment, the pressure roller 11 and the pressure pin 15 are integrated with the laser processing head 1 in the same manner as in the first embodiment, while the jig 107 as a positioned portion is applied to the lower plate material Wd. Positioning is in contact.

  Then, the laser processing head 1 is provided with the same positioning mechanism 91 as in the first embodiment, and the laser processing head 1 is positioned with respect to the jig 107 by the horizontal member 93 and the vertical member 95 of the positioning mechanism 91. The posture with respect to the workpiece W is appropriately secured.

  The above-described positioning mechanism 91 and jig 107 constitute a pressurizing portion position defining means.

  In each of the sixth to eighth embodiments described above, a pair of positioning mechanisms 91 or 101 may be provided on both sides of the laser processing head 1. Thereby, it is possible to cope with the case where the positions of the protrusion 5 and the jig 71 are reversed with respect to the laser irradiation portion 7.

It is a side view of the laser welding apparatus which shows the 1st Embodiment of this invention. It is A arrow directional view of FIG. It is the perspective view which simplified and showed the state which is performing laser welding with the laser welding apparatus of FIG. It is operation | movement explanatory drawing which shows the pressurization operation | movement with respect to the workpiece | work by the laser welding apparatus of FIG. It is explanatory drawing which shows the example in which the positional relationship of the projection part, a pressure roller, and the laser irradiation site | part in the laser welding apparatus of FIG. 1 and the height of the projection part changed. It is explanatory drawing which shows the structure of the clearance securing part replaced with the projection part of 1st Embodiment, (a) is the example which inserted the different material between two board | plate materials, (b) turned upwards to the upper board | plate material. This is an example in which a bent portion to be bent is provided. Shows the relationship between each value based on the distance between the protrusion, pressure roller, and pressure pin, the height of the protrusion, the gap size in the pressure pin, and the height difference between the pressure roller and the pressure pin. It is explanatory drawing. It is a front view corresponding to Drawing 4 (b) concerning the 3rd embodiment of the present invention. It is a perspective view corresponding to FIG. 3 concerning the 4th Embodiment of this invention. It is operation | movement explanatory drawing which each shows the state (a) before pressurization in the 4th Embodiment, and the state (b) after pressurization. It is the schematic top view which shows the welding operation of the laser welding apparatus concerning the 5th Embodiment of this invention. It is a side view corresponding to FIG. 1 of the laser welding apparatus which shows the 6th Embodiment of this invention. It is the front view seen from the right direction (welding progress direction front) of FIG. It is a schematic diagram of the laser welding apparatus shown in FIG. It is a schematic diagram corresponding to FIG. 14 of the laser welding apparatus which shows the 7th Embodiment of this invention. It is a schematic diagram corresponding to FIG. 14 of the laser welding apparatus which shows the 8th Embodiment of this invention.

Explanation of symbols

W Work Wu, Wd Plate material 5 Projection (clearance securing part)
7 Laser beam irradiation part 11 Pressure roller (first pressure part)
15 Pressure pin (second pressure part)
45 Dissimilar material (clearance securing part)
47 Bent part (clearance securing part)
49 Roller side receiving jig (work receiving part)
51 Projection side receiving jig (work receiving part)
91 Positioning mechanism (position defining means, pressure part position defining means)
97 Vertical positioning protrusion (contact part)
99 Horizontal positioning protrusion (contact part)
101 Positioning mechanism (position defining means)
103 Vertical position sensor (position detection means)
105 Left / right position sensor (position detection means)
107 Jig (positioned part, pressure part position defining means)

Claims (16)

  In a laser welding apparatus for performing laser welding on a workpiece surface-treated with a coating layer that generates gas by heating with a lap joint of two plate members, a gap securing portion for forming a gap between the two plate members And a first pressurizing unit that pressurizes the two plate members in contact with each other in the vicinity of the gap securing unit, and the two sheets between the first pressurizing unit and the gap securing unit. Pressurizing is performed in the direction in which the two plates are in contact with each other in a state where the gap is secured with respect to the vicinity of the laser beam irradiation portion having a gap between the plates, and the pressing direction with respect to the first pressure unit A laser welding apparatus characterized in that a second pressurizing part installed at a position deviated by a prescribed dimension is provided.   The said 2nd pressurization part pressurizes so that the clearance gap between the said 2 board | plate materials in the said laser beam irradiation site | part vicinity may be more than the minimum allowable value which can escape the gas generated by the said heating. The laser welding apparatus according to 1.   The workpiece receiving portion for sandwiching the two plate members between the two pressure members is provided on the opposite side of the first pressure portion with the two plate members interposed therebetween. Item 3. The laser welding apparatus according to Item 1 or 2.   The workpiece receiving portion for receiving the two plate materials is provided in a portion corresponding to the gap securing portion on the opposite side of the first pressure member with the two plate materials interposed therebetween. Item 4. The laser welding apparatus according to any one of Items 1 to 3.   The first and second pressurizing portions can be integrally rotated about the center axis of the laser beam with respect to the laser processing head, according to any one of claims 1 to 4. The laser welding apparatus as described.   The first pressurizing unit is separated from the laser processing head that irradiates laser light, while the second pressurizing unit is integrated with the laser processing head, and the second pressurizing unit secures the gap. In this state, when pressurizing in the direction in which the two plate members are in contact with each other, there is provided a position defining means for defining a relative positional relationship between the first pressurizing unit and the second pressurizing unit. The laser welding apparatus according to any one of claims 1 to 4.   The laser welding apparatus according to claim 6, wherein the position defining means is provided integrally with the laser processing head as a contact portion that contacts the first pressurizing portion.   The position defining means is based on a detection operation of a position detecting means for detecting a position of the first pressurizing part in a state where the two plate members are pressed to contact each other. The laser welding apparatus according to claim 6, wherein a relative positional relationship with the second pressure member is defined.   The first pressurizing unit and the second pressurizing unit are integrated with a laser processing head that emits laser light, and the first pressurizing unit and the second pressurizing unit pressurize the two plate materials. 6. The laser welding apparatus according to claim 1, further comprising a pressing portion position defining means for defining a positional relationship with respect to the two plate members.   The pressurizing portion position defining means includes: a positioned portion provided on the workpiece side; and a contact portion provided on the laser processing head and contacting the positioned portion. The laser welding apparatus as described.   With the pressure applied to the two plate members by the first pressurizing unit being constant, the second pressurizing unit has secured the gap in the vicinity of the laser beam irradiation site. The laser welding apparatus according to any one of claims 1 to 10, wherein pressure is applied in a direction in which the plate members are in contact with each other.   12. The laser welding apparatus according to claim 11, wherein the second pressurizing unit increases the pressure applied to the two plate members as being closer to the gap securing unit.   The said 2nd pressurization part enlarges the applied pressure to the said 2 board | plate material, so that the clearance gap between the said 2 board | plate materials secured by the said clearance ensuring part is large. Laser welding equipment.   The laser welding apparatus according to any one of claims 1 to 13, wherein the second pressurizing unit is configured to pressurize two places on both sides of the welding progress direction with respect to the laser light irradiation part. .   The two pressurizing parts of the second pressurizing unit can be moved relative to each other in the pressurizing direction, and a pressurizing unit position detecting unit for detecting the position in each pressurizing direction is provided, and the position detecting unit detects this. 15. The laser welding apparatus according to claim 14, further comprising an abnormality determining unit that determines that the pressure is abnormal when the difference between the positions deviates from a specified value.   In the laser welding method of performing laser welding on a workpiece surface-treated with a coating layer that generates gas by heating with a lap joint of two plate materials, a gap is formed between the two plate materials by a gap securing portion, A pressure is applied by a first pressurizing unit to bring the two plate members into contact with each other in the vicinity of the gap securing part, and the 2 between the first pressurizing part and the gap securing part in this pressurized state. The vicinity of the laser beam irradiation part having a gap between the two plate materials is defined in the pressurizing direction with respect to the first pressurizing portion in a direction in which the two plate materials are in contact with each other while the gap is secured. A laser welding method, wherein pressurization is performed by a second pressurizing unit installed at a position shifted by a dimension of.

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