JP6027483B2 - Arc welding method - Google Patents

Description

  The present invention relates to an arc welding method using molten electrode type arc welding such as MIG welding.

  When a metal having good thermal conductivity is welded by a melting electrode, the electrode melts simultaneously with the generation of the arc, so that insufficient penetration occurs near the starting point of the weld. Therefore, conventionally, a welding method has been proposed in which MIG welding is performed after generating a TIG arc and heating the base material to a necessary temperature (see, for example, Patent Document 1).

JP-A-3-264161

  In patent document 1, it considers the application to the welding construction location where a welding part is short. However, if the welded part is long or has a complicated shape, one welded part may not be processed in one pass. For example, when an endless weld is set on the base material supported by the jig, it is difficult to process in one pass.

  Therefore, the present invention has an object of arc welding of a base material while suppressing a lack of penetration and a surplus height even if a welded portion is long or has a complicated shape.

  An arc welding method according to the present invention includes a first heating step of preheating a base material by generating a non-molten electrode arc at a predetermined portion on a welded portion to be welded, and extending the welded portion from the predetermined portion. A first welding step in which first arc welding is performed toward one side of the current direction, a second heating step in which a non-molten arc is generated at the predetermined portion to reheat the base material, and the predetermined And a second welding step of performing second melting electrode arc welding from the part toward the other side in the extending direction of the welded portion.

  According to the method, prior to performing the first melting electrode arc welding, the vicinity of the starting point of the first melting electrode arc welding is heated by the non-melting electrode arc. Since the non-melting electrode arc is used, the base metal is efficiently heated in a short time, and sufficient penetration can be obtained near the starting point of the first melting electrode arc welding. Quality can be increased. Then, prior to performing the second melting electrode arc welding along the same welded portion, the vicinity of the starting point of the second melting electrode arc welding is also heated by the non-melting electrode arc. The welding quality in welding can also be increased. When molten electrode arc welding is performed through a heating process using a non-molten electrode arc, the bead height is relatively small near the starting point. Since the vicinity of the starting point of the first and second melting electrode type arc weldings is aligned at the same place, even if one bead is continuously formed integrally by overlapping two beads, the bead near the starting point The height is substantially equal to the bead height at the remaining portion. In this way, when performing molten electrode arc welding in two steps along one welded portion, it is possible to obtain a weld bead that suppresses insufficient penetration and suppresses the height of surplus.

  The welded portion is endless, and in the first welding step, the first molten electrode arc welding is performed from the predetermined portion to an end point on the welded portion toward the one side in the extending direction of the welded portion. In the second welding step, the second molten electrode arc welding may be performed from the predetermined portion to the end point toward the other side in the extending direction.

  According to the said method, even if a welding part is endless, the arc welding which has the above-mentioned effect | action can be performed by performing a melting pole type arc welding in two steps.

  The base material may be a vehicle frame, the predetermined portion may be located on the outer surface side of the frame, and the end point may be located on the opposite side to the outer surface side.

  According to the method, the vicinity of the start point of the bead can be positioned on the outer surface side.

  The base material may be an aluminum alloy, the non-melting electrode arc may be a TIG arc, and the melting electrode arc welding may be MIG welding.

  According to the above method, even if the welded portion is long or complicated with respect to a metal having good heat conduction, it is possible to perform arc welding while eliminating lack of penetration.

  The width of the molten pool obtained in each of the first heating step and the second heating step may be made smaller than the bead width obtained in each of the first welding step and the second welding step.

  According to the method, since the molten pool is small, the consumption of the welding wire is reduced. In addition, welding marks are less noticeable.

  According to the present invention, even if the welded part is long or has a complicated shape, it is possible to arc-weld the base material while suppressing insufficient penetration and extra height.

1 is a block diagram illustrating a schematic configuration of an arc welding apparatus according to a first embodiment. It is a flowchart which shows the arc welding performed by the arc welding apparatus shown in FIG. It is an effect | action figure which shows the procedure of the arc welding shown in FIG. 3A shows the first heating process, FIG. 3B shows the first welding process, FIG. 3C shows the second heating process, and FIG. 3D shows the second welding process. It is a figure which shows the frame assembly of the motorcycle which can be manufactured using the arc welding apparatus which concerns on 2nd Embodiment. 4 (a) is a left side view, FIG. 4 (b) is a view from the arrow b in FIG. 4 (a), and FIG. 4 (c) is a view from the arrow c in FIG. 4 (a). It is a front view which shows the arc welding apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the arc welding performed by the arc welding apparatus shown in FIG. It is an effect | action figure which shows the procedure of the arc welding shown in FIG. 7A shows the first heating process, FIG. 7B shows the first welding process, FIG. 7C shows the second heating process, and FIG. 7D shows the second welding process.

  Hereinafter, embodiments will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or corresponding element through all figures, and the overlapping detailed description is abbreviate | omitted.

[Welding equipment]
Drawing 1 is a key map showing the outline composition of arc welding device 1 concerning an embodiment. As shown in FIG. 1, the arc welding apparatus 1 has a frame 2 that forms a welding space 3, and performs hot electrode arc welding on a base material 100 in the welding space 3. The arc welding apparatus 1 includes a welding jig 11, a jig robot 12, a non-molten electrode torch 13, a molten electrode torch 14, a non-molten electrode welding robot 15, and a molten electrode type welding robot 16. In addition. These devices 11 to 16 are arranged in the welding space 3. The arc welding apparatus 1 includes a non-melting-type controller 31 and a melting-type controller 32 as main elements of its control system.

  The base material 100 is fixed and supported on the welding jig 11 by using a restraining tool so that the position and posture with respect to the welding jig 11 do not change. The welding jig 11 is attached to a jig robot 12 provided on the frame 2. The jig robot 12 displaces the position and posture of the welding jig 11 and the base material 100 supported by the jig relative to the frame 2.

  As an example, the jig robot 12 includes a traveling body 21 that can travel straight in a traveling direction horizontal to the frame 2, and a tilting body 22 that can tilt around a tilt axis that is horizontal with respect to the traveling body 21. The welding jig 11 is attached to the tilting body 22 so as to be turnable around a turning axis that is not parallel to the tilting axis. The jig robot 12 tilts the welding jig 11, a traveling actuator 23 for causing the traveling body 21 to travel straight with respect to the frame 2, a tilting actuator 24 for tilting the tilting body 22 relative to the traveling body 21, and the welding jig 11. And a turning actuator 25 for turning the body 22. When these actuators 23 to 25 are operated, the position of the welding jig 11 and the base material 100 supported by the welding jig 11 can be changed in the traveling direction, and the posture can be changed around the tilt axis and the turning axis. However, the configuration of the jig robot 12 is merely an example, and can be changed as appropriate.

  The non-molten electrode torch 13 is a welding torch capable of performing non-molten electrode arc welding, and when welding the base material 100, the non-molten electrode arc at a predetermined portion on the welded portion 101 to be welded. Is generated. The welding electrode torch 14 is a welding torch capable of performing welding electrode arc welding. When welding the base material 100, the welding part 101 extends from the predetermined portion after heating by the non-melting electrode torch 13. Welding type arc welding is performed along the current direction.

  The non-molten electrode torch 13 is not used for performing non-molten electrode arc welding on the base material 100, but heats the base material 100 before the molten electrode arc welding using the molten electrode torch 14. To be used. As a result, the lack of penetration near the starting point of the electrode arc welding can be solved. For this reason, the non-melting electrode type torch 13 does not need to include a device (for example, a device for feeding a filler material) that may be required for welding but is not required for heating.

  Although not shown in detail, when the base material 100 is fixed to the welding jig 11, the base material 100 is welded to the welding machine ground electrode (not shown) of the non-molten electrode torch 13 and the molten electrode torch 14. Each machine earth electrode (not shown) is connected via a cable (not shown). Thereby, the two torches 13 and 14 can generate an arc.

  The non-melting electrode torch 13 is a TIG welding torch capable of performing TIG welding by generating a TIG arc as a non-melting electrode arc from a tungsten electrode while injecting an inert gas (for example, argon) as a shielding gas. Can be applied. A plasma arc welding torch capable of performing plasma arc welding by ejecting a plasma jet from an electrode made of tungsten or other material may be applied.

  The welding electrode torch 14 is supplied with a welding wire which is an electrode for generating an arc and also a welding material while injecting an inert gas (for example, argon) as a shielding gas, thereby performing MIG welding. A MIG welding torch can be applied. A carbon dioxide arc welding torch using carbon dioxide gas (for example, carbon dioxide) as a shielding gas, or a MAG welding torch using a mixed gas of an inert gas and carbon dioxide gas as a shielding gas may be applied. A torch capable of performing submerged arc welding or a torch capable of performing self-shielded arc welding can also be applied.

  When the base material 100 is an aluminum alloy, it is preferable to apply a TIG welding torch to the non-molten torch 14 and apply a MIG welding torch to the molten torch 14. Thereby, cost can be suppressed and welding quality can be made high.

  The non-molten welding robot 15 is an articulated industrial robot including a base 15a and a multi-joint arm 15b provided on the base 15a. Is installed. The melting electrode welding robot 16 is also an articulated industrial robot including a base 16a and a multi-joint arm 16b provided on the base 16a, and the melting-type torch 14 is attached to the tip of the multi-joint arm 16b. Is done. As an example, the multi-joint arms 15b and 16b are vertical multi-joint types, and the positions and postures of the non-melting-type torch 13 and the melting-type torch 14 in the welding space 3 according to the operation of the multi-joint arms 15b and 16b. It changes in three dimensions.

  The two welding robots 15 and 16 are arranged in the welding space 3 in a suspended state. That is, the two welding robots 15 and 16 are in a state in which the bases 15a and 16a are fixed to the inner surface of the ceiling portion of the frame 2 and the articulated arms 15b and 16b extend from the bases 15a and 16a so as to bend downward. Supported by the frame 2. The jig robot 12 is provided at the bottom of the frame 2, and the base material 100 is generally disposed at the center in the vertical direction within the welding space 3.

  The non-melting-type controller 31 controls the non-melting-type welding robot 15. That is, the plurality of arm actuators 15d corresponding to the joints 15c of the non-melting-type welding robot 15 are controlled, and thereby the positions and postures of the multi-joint arm 15b and the non-melting-type torch 13 are controlled. The non-melting-type controller 31 may also control the operation of the non-melting-type torch 13 (that is, generation and stop of an arc).

  The melting electrode type controller 32 controls the melting electrode type welding robot 16. That is, the plurality of arm actuators 16d corresponding to each of the joints 16c of the melting electrode type welding robot 16 are controlled, and thereby the positions and postures of the multi-joint arm 16b and the melting electrode type torch 14 are controlled. The melting electrode type controller 32 may control the operation of the melting electrode type torch 14 (that is, generation and stop of the arc and feeding and stopping of the welding wire) together.

  The electrode controller 32 may control the jig robot 12 together. That is, the actuators 23 to 25 of the jig robot 12 may be controlled so that the position and posture of the welding jig 11 and the base material 100 supported by the welding jig 11 may be controlled. If the dedicated controller is eliminated from the jig robot 12 in this way, the control system hardware is simplified.

[Operation]
FIG. 2 is a flowchart showing a procedure of arc welding executed by the arc welding apparatus 1 shown in FIG. FIG. 3 is an operation diagram of the arc welding shown in FIG. Although detailed illustration is omitted in the present embodiment, in preparation for causing the arc welding apparatus 1 to perform arc welding automatically, the operator attaches the base material 100 to the welding jig 11 and starts welding with an operation panel (not shown). Enter the command. In response to this command, arc welding to the base material 100 automatically proceeds according to the procedure shown in FIG. The operations of the torches 13 and 14 and the base material 100 in the following description are controlled by the corresponding controllers 31 and 32 unless otherwise specified.

  Here, as an example, there is only one welded portion 101 to be welded to the base material 100, and even if the base material 100 is attached to the welding jig 11 in a state where the position and orientation are constrained, the welded portion 101 is It is assumed that it is not hidden by the welding jig 11 or the tilting body 22. When a plurality of welds 101 are used, or even when the base material 100 is attached to the welding jig 11, a part of the welded part 101 is hidden by the welding jig 11 or the tilting body 22. In addition, by applying the arc welding according to the present embodiment as described later, a required welding operation can be performed on the base material 100 (see the second embodiment and FIGS. 4 to 7).

―Air cut (Preparation for welding and heating) ―
When a welding start command is input, first, the melting electrode welding robot 16 and the jig robot 12 are driven to perform air cutting of the melting electrode torch 14 and the base material 100 (step S111). Thereby, the melting electrode type torch 14 moves from the origin position to the first welding preparation position, and the welding jig 11 and the base material 100 move from the origin position to the first jig standby position. The air cutting of the melting electrode torch 14 and the base material 100 may be performed in parallel or sequentially. When the molten electrode type torch 14 moves to the first welding preparation position and the base material 100 moves to the first jig standby position, the molten electrode type torch 14 comes close to the base material 100 and is to be welded. It arrange | positions so that it may estrange slightly from the predetermined site | part 101P on 101 (refer the positional relationship with respect to the base material 100 of the melting type torch 14 shown to Fig.3 (a)).

  The “predetermined part 101P” is a part between two end points on the welded part 101 if the welded part 101 has a closed line segment shape (in other words, a straight line sandwiched between two end points). If it is endless, it is an arbitrary part on the welded part 101. In other words, the welded portion 101 extends from the predetermined portion 101P to both sides in the extending direction.

  Next, the non-melting-type robot 15 is driven to cut the air of the non-melting-type torch 13 (step S112), and the non-melting-type torch 13 moves from its origin position to the first heating position. When the non-molten electrode torch 13 is moved to the first heating position after the base material 100 is positioned at the first jig standby position, the non-molten electrode torch 13 is moved closer to the predetermined portion 101P than the molten electrode torch 14. The non-melting-point arc 110 can be generated near the predetermined portion 101P (see the positional relationship of the non-melting-type torch 13 with respect to the base material 100 shown in FIG. 3A).

―First heating―
When the air cut to the first heating position of the non-molten torch 13 is completed, the non-molten torch 13 generates the non-molten arc 110 for a predetermined period (first heating step S113). Thereby, the said predetermined part 101P is heated and the molten pool 102 is formed in the said predetermined part 101P by this (refer Fig.3 (a)).

―Air cut (withdrawal and welding start) ―
When the non-molten arc 110 is stopped, the non-molten welding robot 15 is driven to cut the air of the non-molten torch 13 (step S114), and the non-molten torch 13 is moved from the first heating position. Move to the first welding retract position. The first welding evacuation position is a position sufficiently away from these in order to avoid interference with the base material 100 and the welding electrode welding robot 16 when the next welding electrode arc welding is performed, and is different from the origin position. May be.

  In parallel with the air cut of the non-melting type torch 13, the melting type welding robot 16 is driven to perform the air cutting of the melting type torch 14 (step S115). The melting electrode torch 14 moves from the first welding preparation position to the first welding start position. The start point of the air cut of the melting electrode type torch 13 may be the same as the start time of the air cut to the first welding retreat position of the non melting point type torch 14, but immediately before the stop of the non melting electrode type arc (that is, the arc It may be advanced to the point of occurrence).

-1st electrode type arc welding-
When the air cutting of the melting electrode type torch 14 is completed, the first melting electrode type arc welding is performed from the predetermined portion 101P toward one side in the extending direction of the welding portion 101 using the melting electrode type torch 13 ( 1st welding process S116). That is, the melting electrode torch 14 generates the melting electrode arc 115 from the welding wire while feeding the welding wire, and starts the first melting electrode arc welding starting from a certain position within the predetermined portion 101P. To do.

  When the melting electrode type arc welding is started, the melting electrode type welding robot 16 and the jig robot 12 are driven to move the melting electrode type torch 14 relative to the base material 100 to one side in the extending direction of the welded portion 101 ( (Refer FIG.3 (b)). This relative movement can be realized only by moving the melting type torch 14 with respect to the frame 2, or by only moving the welding jig 11 and the base material 100 with respect to the frame 2. It is also realized by combining these two types of movements.

  When the melting electrode type arc welding proceeds to a predetermined end point 101Q on the welding portion 101, the feeding of the welding wire is stopped and the arc is stopped. A bead 121 is placed on the welded portion 101 to be welded from the start point in the predetermined portion 101P to the end point 101Q. The start end 121S of the bead 121 is placed in the predetermined part 101P, and the end 121E of the bead 121 is placed on the end point 101Q.

  The “end point 101Q” can be set to an end point on one side in the extending direction when viewed from the predetermined portion 101P when the welded portion 101 is formed in a closed line segment, and the welded portion 101 is made endless. When formed, it is set at an arbitrary position on the welded portion 101 that is out of the predetermined portion 101P. By performing the first welding step S116, the melting electrode torch 14 moves from the first welding start position to the first welding end position, and the base material 100 moves from the first jig standby position to the first welding end position. Move up.

―Air cut (Preparation for welding and heating) ―
When the first melting electrode type arc welding is completed in this way, the melting electrode type welding robot 16 and the jig robot 12 are driven to perform air cutting of the melting electrode type torch 14 and the base material 100 (step S161). . That is, the melting electrode torch 14 moves from the first welding end position to a position (second welding preparation position) corresponding to the predetermined portion 101P of the welded portion 101 to be welded next, and the base material 100 It moves from the first welding end position to a position (second jig standby position) corresponding to the predetermined portion 101P. In the present embodiment, since it is assumed that there is one welded portion 101, “the welded portion 101 to be welded next” is the welded portion 101 that is the welding target in the first welding step S116. Of these, the bead is not yet placed. Here, the “predetermined portion 101P” generates a non-molten electrode arc in the first heating step S113 and positions the start point 121S of the first molten electrode arc welding in the first welding step S116. It is the same as the predetermined portion 101P.

  When the molten electrode type torch 14 moves to the second welding preparation position and the base material 100 moves to the second jig standby position, the molten electrode type torch 14 comes close to the base material 100 and is to be welded. It is arranged so as to be slightly separated from the predetermined portion 101P on 101.

  When the air cutting of the melting electrode torch 14 and the base material 100 is completed, the non-melting electrode welding robot 15 is driven to perform the air cutting of the non-melting electrode torch 13 (step S162). However, it moves to the 2nd heating position corresponding to predetermined part 101P from the 1st welding retreat position.

  Note that the first and second second electrode types of arc welding and second welding electrode arc welding have the welding portion 101 as a welding target in the end, but the welding direction is opposite. Yes. The second welding preparation position (particularly the posture) does not coincide with the first welding preparation position in consideration of the convenience of relative movement of the melting electrode torch 14 with respect to the base material 100 in the second melting electrode arc welding. In addition, the second jig standby position (especially the posture) may not coincide with the first jig standby position. The second heating position may not be coincident with the first heating position, particularly when the second jig standby position is different from the first jig standby position.

  When the molten electrode type torch 14 moves to the second welding preparation position and the base material 100 moves to the second jig standby position, the molten electrode type torch 14 comes close to the base material 100 and is to be welded. It arrange | positions so that it may leave a predetermined part 101P on 101 a little (refer the positional relationship with respect to the base material 100 of the melting type torch 14 shown in FIG.3 (c)). When the non-molten electrode torch 13 moves to the second heating position after the base material 100 is positioned at the second jig standby position, the non-molten electrode torch 13 is closer to the predetermined portion 101P than the molten electrode torch 14 is. Then, the non-melting-type arc 110 can be generated at the predetermined portion 101P (see the positional relationship of the non-melting-type torch 13 with respect to the base material 100 shown in FIG. 3C).

-Second heating-
When the air cut to the second heating position of the non-molten torch 13 is completed, the non-molten torch 13 generates the non-molten arc 110 for a predetermined period (second heating step S163). As a result, the predetermined portion 101P is reheated, whereby the molten pool 102 is re-formed in the predetermined portion 101P (see FIG. 3C).

  Within the predetermined portion 101P, the start end 121S of the bead 121 is placed in the first melting electrode type arc welding. In the second heating step S163, the non-melting-point arc 110 may be generated also at the start end 121S of the bead 121 placed in the first welding step S116, and thereby the start end 121S of the bead 121 may be melted.

―Air cut (withdrawal and welding start) ―
When the non-molten electrode arc 110 stops, the non-molten electrode welding robot 15 is driven to perform air cutting of the non-molten electrode torch 13 (step S164), and the non-molten electrode torch 13 is moved from the second heating position. Move to the second welding retract position. The second welding retreat position is a position sufficiently away from these in order to avoid interference with the base material 100 and the welding electrode welding robot 16 when the next welding electrode arc welding is performed, and is different from the origin position. It may be the same as or different from the first welding retract position.

  In parallel with the air cut of the non-melting type torch 13, the melting type welding robot 16 is driven to perform the air cutting of the melting type torch 14 (step S165). The melting electrode torch 14 moves from the second welding preparation position to the second welding start position. The start point of the air cut of the melting electrode type torch 13 may be the same as the start time of the air cut to the first welding retreat position of the non melting point type torch 14, but immediately before the stop of the non melting electrode type arc (that is, the arc It may be advanced to the point of occurrence).

―Second melting electrode type arc welding―
When the air cut of the melting electrode torch 14 is completed, the second melting electrode arc welding is performed from the predetermined portion 101P toward the other side in the extending direction of the welded portion 101 using the melting electrode torch 13 (first). 2 welding step S166). That is, the melting electrode torch 14 generates a melting electrode arc 115 from the welding wire while feeding the welding wire, and is opposite to the first melting electrode arc welding starting from a certain position within the predetermined portion 101P. The second molten electrode arc welding is started toward the side. When the melting electrode type arc welding is started, the melting electrode type welding robot 16 and the jig robot 12 are driven to move the melting electrode type torch 14 relative to the base material 100 to one side in the extending direction of the welded portion 101 ( (Refer FIG.3 (d)).

  When the melting electrode type arc welding proceeds to a predetermined end point 101R on the welded portion 101, the feeding of the welding wire is stopped and the arc is stopped. A bead 122 is placed on the welded portion 101 to be welded from the start point in the predetermined portion 101P to the end point 101R. The start end 121S of the bead 122 is placed in the predetermined portion 101P, and the end 122E of the bead 121 is placed on the end point 101R. The start end 122S of the bead 122 is continuous with the start end 121S of the bead 121, and the continuous bead 120 including the beads 121 and 122 is placed on the welded portion 101. However, in this bead 120, the welding directions of the beads 121 and 122 are opposite to each other, so that the bead waves are formed symmetrically with respect to the start ends 121 </ b> S and 1222 </ b> S of the beads 121 and 122.

  The “end point 101R” can be set to an end point on the other side in the extending direction when viewed from the predetermined portion 101P when the welded portion 101 is formed in a closed line segment, and the welded portion 101 becomes endless. When formed, it is set to a position that is the same as or close to the end point set in the first melting electrode type arc welding. By performing the second welding step S166, the melting electrode torch 14 moves from the second welding start position to the second welding end position, and the base material 100 moves from the second jig standby position to the second welding end position. Moving.

―Air cut (return) ―
When the required welding operation is completed, the melting electrode welding robot 16 and the jig robot 12 are driven to perform air cutting of the melting electrode torch 14 and the base material 100 (step S171). That is, the melting electrode torch 14 returns from the second welding end position to the origin position, and the base material 100 returns from the second welding end position to the origin position. When the air cutting of the melting electrode torch 14 and the base material 100 is completed, the non-melting electrode welding robot 15 is driven to perform the air cutting of the non-melting electrode torch 13 (step S172). Returns from the second welding retracted position to the origin position. When the torch 13, 14 and the base material 100 are all returned to the origin position, the arc welding is finished.

[Action]
According to the arc welding method described above, the vicinity of the start point (predetermined portion 101P) of the first molten electrode arc welding is heated by the non-molten electrode arc prior to performing the first molten electrode arc welding. Since the non-melting electrode type arc is used, the base material 100 is efficiently heated in a short time, and sufficient penetration can be obtained in the vicinity of the starting end of the first melting electrode type arc welding. Therefore, the welding quality in the first melting electrode type arc can be improved. Thereafter, prior to performing the second melting electrode arc welding along the same welded portion 101, the vicinity of the start end of the second melting electrode arc welding is also heated by the non-melting electrode arc 110, so that the second It is possible to improve the welding quality in the arc electrode welding.

  When the melting electrode arc is performed through the heating process by the non-melting electrode arc 110, it is not necessary to keep the melting electrode arc at the welding start point in order to ensure the penetration. Therefore, it is possible to suppress the extra height in the vicinity of the welding start point. In particular, since the starting points of the first and second melting electrode arc weldings are aligned, even if one continuous bead 120 is formed from the two beads 121, 122, the two beads 121, 122 The bead height in the vicinity of the starting point can be made substantially equal to the bead height in the remaining portion. In this way, when performing molten electrode arc welding in two steps along one welded portion 101, it is possible to suppress insufficient penetration and extra height. In this embodiment, since the start end 121S of the bead 121 placed in the first welding step S116 is melted in the second heating step S163, the bead 122 placed in the second welding step S166 is the first welding step S116. It is possible to satisfactorily prevent the bead 121 placed on the top of the bead 121 from being overlapped, which is useful for suppressing the height of the surplus.

  As shown in FIG. 3B, the width of the molten pool 102 formed in the first heating step S113 is made smaller than the width of the bead 121 formed in the subsequent first welding step S116. Thereby, while saving of a welding wire can be aimed at, the welding trace becomes inconspicuous and the bead 121 which improved the beauty | look can be set | placed on a welding part. Such width management can be realized by a method of setting the cleaning width to be narrowed in the welding machine of the melting electrode torch 13 when the non-melting electrode arc 110 is generated by the non-melting electrode torch 13. It is. Further, such width management is performed on the combination of the second heating step S163 and the second welding step S166 in addition to or instead of the combination of the first heating step S113 and the first welding step S116. May be. That is, it is sufficient that the width of the molten pool 102 is smaller than the width of the bead 120 in at least one of the first welding step S116 and the second welding step S166.

(Second Embodiment)
[Base material]
Hereinafter, a second embodiment will be described. The arc welding method according to the second embodiment relates to a method for performing arc welding on a base material when a welded portion to be welded is endless. In the following description, welding is performed on the welded portion. A motorcycle frame assembly is illustrated as an example of a manufactured product.

  FIGS. 4A to 4C are views showing a motorcycle frame assembly 150 that can be manufactured by using the arc welding apparatus according to the second embodiment. 4A is a left side view of the frame assembly 150, and FIG. 4B is a view as viewed in the direction of the arrow b in FIG. 4A (that is, the frame assembly 150 is below the head pipe portion 151 in the axial direction). FIG. 4C is a view taken along the arrow c in FIG. 4A (that is, a rear view of the frame assembly 150). Note that the concept of the direction of the frame assembly 150 described with reference to FIG. 4 is based on the direction viewed from the driver riding the motorcycle equipped with the frame assembly 150.

  As shown in FIGS. 4A to 4C, a frame assembly 150 according to the illustrated example includes a cylindrical head pipe portion 151 and a pair of main frame portions that are separated from the head pipe portion 151 to the left and right and extend rearward. 152, 153 (illustration of the right main frame portion 153 is omitted in FIG. 4A). As shown in FIG. 4C, the frame assembly 150 according to the illustrated example includes a center crossbar portion 154 that connects the main frame portions 152 and 153 in the left-right direction at the front and rear central portions, and the main frame portions 152 and 153. And a rear crossbar portion 155 that connects the left and right sides at the rear end.

  4A to 4C, the frame assembly 150 is manufactured by performing arc welding using five metal materials 161 to 165 as base materials. The first metal material 161 roughly corresponds to the head pipe portion 151, and has joint portions 161a and 161b that protrude from the portion that forms the head pipe portion 151 to the left and right. The second metal material 162 roughly corresponds to the left main frame portion 152, a joint portion 162 a formed at the front end portion and welded to the joint portion 161 a, a front-rear central portion and a rear end of a portion forming the left main frame portion 152. Each of the parts has joint parts 162b and 162c that protrude inward in the vehicle width direction from the inner surface of the part. The third metal material 163 roughly corresponds to the right main frame portion 153 and has joint portions 163 a to 163 c like the second metal material 162. The fourth metal material 164 substantially corresponds to the center crossbar portion 154, and is formed at the left end portion and is joined to the joint portion 162b and the joint portion 164a is welded to the right end portion and is welded to the joint portion 163b. 164b. The fifth metal material 165 roughly corresponds to the rear crossbar portion 155, and is formed at the left end portion to be welded to the joint portion 162c, and to the right end portion to be welded to the joint portion 163c. 165b.

  4A to 4C, the frame assembly 150 is manufactured by performing arc welding on a total of six welding locations 171 to 176. In the welded portions 171 to 176, a first welded portion 171 for welding the joint portions 161a and 162a, a second welded portion 172 for welding the joint portions 161b and 163a, and a third weld for welding the joint portions 162b and 164a. A location 173, a fourth weld location 174 for welding the joint portions 163b and 164b, a fifth weld location 175 for welding the joint portions 162c and 165a, and a sixth weld location 176 for welding the joint portions 163c and 165b are included. It is.

  In general, in the frame assembly 150 of a motorcycle, the metal materials 161 to 165 which are base materials in the production thereof are formed into a tubular shape having a substantially square cross section, so that the six welding locations 171 to 176 are all welded. The welds (or weld lines) 181 to 186 to be performed are endless.

[Welding equipment]
FIG. 5 is a front view showing an arc welding apparatus 201 according to the second embodiment. The arc welding apparatus 201 according to the second embodiment manufactures a frame assembly by performing arc welding with respect to the welded portions 181 to 186 set to the joint portion using the metal materials 161 to 165 described above as a base material. It can be suitably used for. The arc welding apparatus 201 has the same basic configuration as that shown in the first embodiment. The frame 202 includes a bottom plate member 204 and a ceiling plate member 205 that are substantially rectangular in a plan view, and four column members 206 that vertically connect the four corners of the bottom plate member 204 and the ceiling plate member 205 (only two front members in FIG. 5). The welding space 203 is formed inside these members 204 to 206 and has a substantially rectangular shape in plan view.

  The traveling body 221 of the jig robot 212 has a slider 221a supported on the bottom plate member 204 so as to be able to travel straight in the traveling direction, and a pair of standing portions 221b extending upward from the slider 221a. The slider 221a is a welding space. In 203, it is arrange | positioned in the center part in the horizontal direction orthogonal to a running direction, and the standing part 221b is facing the said running orthogonal direction. The tilting body 222 is supported by each of the pair of standing portions 221b so as to be tiltable, and tilts above the slider 221a around a tilting axis directed in the orthogonal direction of travel. The welding jig 211 is rotatably mounted on such a tilting body 222, and the welding jig 211 and the base materials 161 to 165 supported by the welding jig 211 are positioned at the center in the vertical direction in the welding space 203. To do.

  The welding robots 215 and 216 are such that the bases 215a and 216a are fixed to the inner surface side of the ceiling plate member 205 and the articulated arms 215b and 216b extend downward from the corresponding bases 215a and 216a so as to bend. , Disposed in the welding space 203. The two welding robots 15 and 16 may be disposed substantially diagonally apart so as to sandwich the welding jig 211 in plan view.

[Operation]
FIG. 6 is a flowchart showing a procedure of arc welding executed by the arc welding apparatus 201 shown in FIG. FIG. 7 is an operation diagram showing the procedure of arc welding shown in FIG. In addition, although detailed illustration is abbreviate | omitted, the arc welding apparatus 201 which concerns on this embodiment is also provided with one or more controllers (not shown) which control the robot 212,215,216 similarly to the said embodiment. The operations of the torches 213 and 214 and the base materials 161 to 166 in the following description are controlled by corresponding controllers unless otherwise specified.

  When the metal materials 161 to 165 illustrated in FIG. 4 and FIG. 5 are used as the base material, the welding portions 181 to 186 are partially tilted with the welding jig 211 or tilted regardless of the orientation of the base materials 161 to 165. It is hidden by the body 222. Therefore, two different postures (first and second postures) for completing the welding on each of the welded portions 181 to 186 in two passes are grasped in advance.

-First heating and first welding-
As shown in FIG. 6, the operator first attaches the base materials 161 to 165 to the welding jig 211 in the first posture (step S201), and issues an instruction to start execution of the first program to the arc welding apparatus 201. This is given to the system (step S202). This first program repeats the same processing as Steps S111 to S116 in the first embodiment, whereby arc welding for the first half of each of the plurality of welds 181 to 186 (ie, the first heating and the first heating). 1 (melting electrode type arc welding) is sequentially performed.

  When the execution of the first program is started, air cutting of the melting electrode torch 214 and the base materials 161 to 165 is performed (step S211), and the melting electrode torch 214 is moved from the origin position to the first welded part (for example, the welded part 181). The base material is moved to the corresponding first welding preparation position, and the base material is moved to the first jig standby position corresponding to the welded portion. Next, air cutting of the non-molten electrode torch 213 is performed (step S212), and the non-molten electrode torch 213 is moved from the origin position to the first heating position corresponding to the welded portion 181.

  Next, the non-molten electrode torch 213 generates a non-molten electrode arc for a predetermined period (first heating step S213), thereby heating the predetermined part 181P of the welded portion 181 and forming a molten pool in the predetermined part 181P. Form (see FIG. 7A). When the predetermined period elapses, the non-molten torch 213 is air cut (step S214), and the non-molten torch 13 is moved from the first heating position to the first welding retreat position. In parallel with the air cutting of the non-melting-type torch 213, air-cutting of the melting-type torch 214 is performed (step S215), and the melting-type torch 214 is moved from the first welding preparation position to the first welding start position. .

  Next, first molten electrode arc welding is performed from the predetermined portion 181P toward one side in the extending direction of the welded portion 181 using the molten electrode torch 214 (first welding step S216). When melting electrode type arc welding is started, the melting electrode type torch 214 is moved relative to the base materials 161 to 165 with respect to one side in the extending direction of the welded portion 181. When the galvanic arc welding proceeds to a predetermined end point 181Q for the first half of the weld 181, the welding wire is stopped and the arc is stopped. A bead 191 is placed on the welded portion 181 to be welded from the start point in the predetermined portion 181P to the end point 181Q (see FIG. 7B). The start end 191S of the bead 191 is placed in the predetermined portion 181P, and the end 191E of the bead 191 is placed on the end point 181Q.

  When the first molten electrode arc welding is completed in this way, the welding process for the first half pass is completed for all of the welded portions 181 to 186 set in the base materials 161 to 165 (ie, step). As long as NO in S217), the above steps S211 to S216 are repeated.

  For example, when the first molten electrode arc welding for the first welded portion 181 is completed and the first molten electrode arc welding is performed for the second welded portion 182, first, in step S 211. Thus, the melting electrode torch 214 is moved from the first welding end position corresponding to the welded welded portion 181 to the first welding preparation position corresponding to the welded portion 182 to be welded next. . In step S211, the base materials 161 to 165 are moved from the first welding end position corresponding to the welded portion 181 to the first jig standby position corresponding to the welded portion 182. In step S212, the non-molten electrode torch 213 is moved from the first welding retreat position corresponding to the welded portion 181 to the first heating position corresponding to the welded portion 182.

  When the welding process for the first half pass is completed for all the welded portions 181 to 186 (S217: YES), the molten electrode type torch 214 and the base materials 161 to 165 are air cut (step S221), and the molten electrode type torch 214 is obtained. Is returned from the first welding end position corresponding to the last welded portion (for example, the welded portion 186) to the origin position, and the base materials 161 to 165 are returned from the first welding end position corresponding to the welded portion 186 to the origin position. To return. Next, air cutting of the non-molten electrode torch 213 is performed (step S222), and the non-molten electrode torch 213 is returned from the first welding retracted position corresponding to the welded portion 186 to the origin position.

-Second heating and second welding-
Next, the operator once removes the base materials 161 to 165 from the welding jig 211, reattaches the removed base materials 161 to 165 to the welding jig 211 in the second attitude described above (step S251), A command to start executing the program is given to the control system of the arc welding apparatus 201 (step S252). This second program repeats the same processing as Steps S161 to S166 in the first embodiment, so that arc welding for the latter half of one pass is performed on each of the plurality of welds 181 to 186 (that is, the second heating and the second heating). (Solder electrode type arc welding 2) is performed sequentially.

  When the execution of the second program is started, air cutting of the melting electrode torch 214 and the base materials 161 to 165 is performed (step S261), and the melting electrode torch 214 is moved from the origin position to the first welded portion (for example, the welded portion 181). The base material 161 to 165 is moved to the second welding standby position corresponding to the welded portion 181 from the origin position. Next, air cutting of the non-molten electrode torch 213 is performed (step S262), and the non-molten electrode torch 213 is moved from the origin position to the second heating position corresponding to the welded portion 181.

  Next, the non-molten electrode torch 213 generates a non-molten electrode arc for a predetermined period (second heating step S263), thereby heating the predetermined part 181P of the welded portion 181 and setting the molten pool in the predetermined part 181P. It forms (refer FIG.7 (c)). When the predetermined period elapses, the non-melting electrode torch 213 is air cut (step S264), and the non-melting electrode torch 213 is moved from the second heating position to the second welding retraction position. In parallel with the air cut of the non-melting-type torch 213, air-cutting of the melting-type torch 214 is performed (step S265), and the melting-type torch 214 is moved from the second welding preparation position to the second welding start position. .

  Next, the second molten electrode arc welding is performed from the predetermined portion 181P toward the other side in the extending direction of the welded portion 181 using the molten electrode torch 214 (second welding step S266). When the melting electrode type arc welding is started, the melting electrode type torch 214 is moved relative to the base material 161-165 with respect to the other side in the extending direction of the welded portion 181. When the galvanic arc welding proceeds to the predetermined end point 181R as the second half of the weld 181, the welding wire feeding is stopped and the arc is stopped. A bead 192 is placed on the welded portion 181 to be welded from the start point in the predetermined portion 181P to the end point 181R (see FIG. 7D). The start end 192S of the bead 192 is placed in the predetermined portion 181P, and the end 192E of the bead 192 is placed on the end point 181R. The start end 192S of the bead 192 continues to the start end 191S of the bead 191. Where the welded portion 181 is endless, the end point 181R is the same as or near the end point 181Q in the first welding step. Therefore, the end 192E of the bead 192 is also continuous with the end 191E of the bead 191. Thereby, on the endless welded portion 181, a bead 190 continuous in a circumferential shape is placed on one of the beads 191 and 192.

  When the second melting electrode arc welding is completed in this way, the welding process for the latter half of one pass is completed for all the welded portions 181 to 186 set in the base materials 161 to 165 (ie, step). As long as NO in S267), the above steps S261 to S266 are repeated.

  When the welding process for the second half of the welds 181 to 186 is completed (S267: YES), the molten electrode torch 214 and the base materials 161 to 165 are air cut (step S271), and the molten electrode torch 214 is used. Is returned from the second welding end position corresponding to the last welded portion (for example, the welded portion 186) to the origin position, and the base materials 161 to 165 are returned from the second welding end position corresponding to the welded portion 186 to the origin position. To return. Next, air cutting of the non-molten electrode torch 213 is performed (step S272), and the non-molten electrode torch 213 is returned from the second welding retracted position corresponding to the welded portion 186 to its origin position.

[Action]
According to the arc welding method described above, even if the welded portion is endless, arc welding with the same effect as in the above embodiment can be performed by performing the melting electrode arc welding in two steps. By adopting the above-described method, it is possible to manufacture the frame assembly 150 while suppressing the lack of penetration and the height of the overfill, and the quality of the frame assembly 150 is improved. In this way, when the frame assembly 150 is targeted, the predetermined portion 181P is set on the surface that forms the appearance, and the end point 181Q is formed on the surface that does not form the appearance (the surface opposite to the outer surface that forms the appearance). , 181R may be set.

  Although the embodiment has been described above, the above configuration and method are merely examples, and can be appropriately changed, deleted, and added without departing from the spirit of the present invention.

  The present invention has an effect that arc welding can be performed on a base material while suppressing insufficient welding and extra height even if the welded portion is long or has a complicated shape. It can be applied to the manufacture of frames.

DESCRIPTION OF SYMBOLS 1,201 Arc welding apparatus 11, 211 Welding jigs 12, 212 Jig robots 13, 213 Non-molten electrode torches 14, 214 Non-molten torches 15, 215 Non-molten electrode welding robots 16, 216 DESCRIPTION OF SYMBOLS 100 Base material 101 Welding part 101P Predetermined part 101Q, 101R End point 102 Weld pool 120, 121, 122 Bead 150 Frame assembly 161-165 Metal material (base material)
171 to 176 Welding points 181 to 186 Welded portions 190, 191, 192 Beads S113, S213 First heating step S116, S216 First welding step S163, S263 Second heating step S166, S266 Second welding step

Claims (5)

A first heating step of preheating the base material by generating a non-melting-point arc at a predetermined site on the weld to be welded;
A first welding step of performing first melting electrode arc welding from the predetermined portion toward one side in the extending direction of the weld portion;
A second heating step of reheating the base material by generating a non-melting arc or irradiating a beam at the predetermined portion;
And a second welding step of performing second melting electrode arc welding from the predetermined portion toward the other side in the extending direction of the welded portion. The weld is endless,
In the first welding step, the first melting electrode type arc welding is performed from the predetermined portion to an end point on the welded portion toward one side in the extending direction of the welded portion,
2. The arc welding method according to claim 1, wherein in the second welding step, the second melting electrode type arc welding is performed from the predetermined portion to the end point toward the other side in the extending direction.   The arc welding method according to claim 2, wherein the base material is a vehicle frame, the predetermined portion is located on an outer surface side of the frame, and the end point is located on the opposite side to the outer surface side.   The arc welding method according to any one of claims 1 to 3, wherein the base material is an aluminum alloy, the non-melting electrode arc is a TIG arc, and the melting electrode arc welding is MIG welding. The width of the molten pool obtained by each of the said 1st heating process and the said 2nd heating process is made smaller than the bead width obtained by each of the said 1st welding process and the said 2nd welding process, respectively. 2. The arc welding method according to item 1.

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