JP6230410B2 - Arc welding method and welding apparatus - Google Patents

Description

  The present invention relates to an arc welding method and a welding apparatus, and more particularly to an arc welding method in which a base material and a filler wire are melted by an arc generated by an electrode and a welding apparatus that executes the arc welding method.

  Japanese Patent Application Laid-Open No. 2009-106985 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2009-154173 disclose arc welding start and end methods in which a base material and a welding wire are melted by an arc generated by an electrode to weld an object to be welded. It is disclosed in the gazette (patent document 2).

  Japanese Patent Application Laid-Open No. 2009-106985 describes a welding start method of two-wire welding in which a consumable electrode wire is used as an electrode and a filler wire that is a second welding wire is fed behind the consumable electrode wire.

  In the above prior art, in order to prevent welding defects at the weld bead start end at the welding start portion of two-wire welding, the filler wire is fed forward and brought into contact with the base material before the arc is fired, and then is fed backward. To keep the distance between the filler wire and the base material constant. Thus, after the arc is ignited, the filler wire is reliably fed to the molten pool, and buckling, breakage, and extreme flaking of the weld bead start end are prevented.

JP 2009-106985 A JP 2009-154173 A

  In a welding method using a filler wire, it is important to insert the filler wire into the molten pool when an appropriate molten pool is formed. If the supply of the filler wire is delayed, the melting of the base material may proceed so much that the molten pool may penetrate the back surface of the base material. If the filler wire is supplied too early, heat input from the arc to the base material is insufficient, and even if the filler wire comes into contact with the base material, there is a risk that it will buckle without melting. All of these cause the welding quality to deteriorate.

  To insert the filler wire when the proper molten pool is formed, change the filler wire feeding timing and filler wire feeding speed according to the base metal plate thickness, groove shape, and welding current. It is necessary to let

  However, conventionally, the control related to the filler wire is a control in which the parameter is fixed to a constant value. When the base material or the groove shape is changed, in order to insert the filler wire in a state where an appropriate molten pool is formed. There were difficulties such as the need to adjust the set value by trial and error.

  An object of the present invention is to provide an arc welding method and welding apparatus in which a base material and a filler wire are melted by an arc generated by an electrode, with improved production efficiency and welding quality.

In summary, the present invention relates to an arc welding method in which a base material and a filler wire are melted and welded by an arc generated by an electrode, and the welding is started from a plurality of data recorded in advance in a database at the start of welding. The processor reads one data based on the input base material information, and the processor determines the filler wire control condition based on the one read data, and the determined filler wire control condition And applying a start of welding by the processor. Each of the plurality of data includes first data indicating a base material shape and a welding finish state, and second data relating to filler wire control. In the reading step, one piece of data is selected by comparing the base material information with the first data. The filler wire control conditions include a condition related to the filler wire feed start timing determined based on the second data.

Preferably, the arc welding method includes a step of moving the welding torch to a retry position different from the planned welding start position in order to retry the generation of the arc when the generation of the arc fails at the planned welding start position; When the generation of the arc at the position fails, the processor reads another data for retry from a plurality of data, the step of moving the arc generated at the retry position to the welding start planned position, and generation And a step of starting the feeding of the filler wire after the arc moved to the welding start scheduled position.

In another aspect, the present invention is an arc welding method in which a base material and a filler wire are melted and welded by an arc generated by an electrode, and at the start of welding, from a plurality of data recorded in advance in a database, The processor reads one piece of data based on the base material information input from the user, and the processor determines the control condition of the filler wire based on the one piece of read data. Applying a control condition to cause the processor to start welding. The arc welding method includes a step of moving the welding torch to a retry position different from the planned welding start position in order to retry the generation of the arc when the generation of the arc fails at the planned welding start position, and an arc at the planned welding start position. In the case where the occurrence of the failure has occurred, the processor reads another data for retry from a plurality of data, the step of moving the arc generated at the retry position to the planned welding start position, and the generated arc And a step of starting feeding of the filler wire after moving to the welding start scheduled position.

  Preferably, the electrode is a consumable electrode wire, and the filler wire is disposed behind the consumable electrode wire in the welding direction.

  In another aspect, the present invention is a welding apparatus that performs welding by causing a control device to execute any one of the above arc welding methods.

  According to the present invention, it is possible to perform control so that the filler wire is inserted into an appropriate molten pool at the start of the arc without performing the adjustment operation every time at the start of welding. As a result, it is possible to prevent a weld defect from occurring at the start end of the weld bead.

It is a block diagram of the welding apparatus common to embodiment. It is a figure for demonstrating the specific shape with which the welding torch and the wire feeding apparatus were mounted | worn with the welding robot which is an example of the torch moving mechanism. It is a figure for demonstrating the distance D from the base material of the front-end | tip part of a filler wire. FIG. 5 is a waveform diagram for explaining the operation of the arc welding method of the first embodiment. It is the figure which showed typically the state of the welding torch and wire immediately after an arc generate | occur | produced in the time t5 of FIG. It is the figure which showed typically the state of the welding torch and the wire at the time of the feeding start of the filler wire in the time t6 of FIG. It is the figure which showed typically the state of the welding torch and the wire of the state which completed formation of the molten pool at the time t7 of FIG. 6 is a flowchart for explaining a welding condition reading operation at the start of welding executed in the first embodiment. It is a figure for demonstrating the database selected by step S2 and used by step S3. It is a figure for demonstrating the retry operation | movement of the arc generation at the time of a welding start. 6 is a diagram for explaining a weld bead formed by the welding start method of Embodiment 2. FIG. It is a flowchart for demonstrating the control in the arc welding start method of embodiment. It is the figure which showed an example of the data stored in the database accessed by step S11 and step S16 of FIG. It is a flowchart explaining the detail of the normal setting of step S14 of FIG. It is a flowchart explaining the detail of the retry setting of step S22 of FIG. 6 is a diagram for explaining an arc welding start method according to Embodiment 2. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a block diagram of a welding apparatus common to the embodiments. 1 shows an example in which the welding apparatus performs two-wire welding, but the present invention is not limited to this. For example, the present invention can be applied to a welding apparatus (for example, a TIG welding apparatus) in which the electrode is not a consumable electrode wire.

  Referring to FIG. 1, welding apparatus 100 includes a welding torch 14, wire feeding devices 25 and 26, a power supply device 22, a torch moving mechanism (robot) 21, and a control device 27. The welding apparatus 100 performs two-wire welding using the consumable electrode wire 3 and the filler wire 4.

  The welding torch 14 is attached to the torch moving mechanism 21. The torch moving mechanism 21 is generally a robot arm or the like, but may be another mechanism. The welding torch 14 has contact tips 1 and 2. The contact chip 1 is provided with a through hole through which the consumable electrode wire 3 can be inserted. The contact chip 2 is provided with a through hole through which the filler wire 4 can be inserted.

  In the 2-wire welding, the welding torch 14 is welded by the torch moving mechanism 21 in a state where the consumable electrode wire 3 is positioned in front of the welding direction indicated by the arrow in FIG. 1 and the filler wire 4 is positioned in the rear of the welding direction. Moved in the direction.

  The power supply device 22 includes a welding power supply 23 and a detection power supply 24. The welding power source 23 is a power source for generating an arc in the consumable electrode wire 3 and supplies a welding current and a welding voltage to the contact tip 1 based on the set welding voltage and welding current. Setting of the welding voltage and the welding current is performed by the control device 27. Also, the set values of the welding voltage and welding current can be changed at any time during welding. The contact chip 1 is electrically connected to the consumable electrode wire 3. Therefore, a welding voltage and a welding current are supplied to the consumable electrode wire 3 from the welding power source 23 via the contact tip 1. Although not shown, the welding power source 23 includes a welding current relay (WCR) that is turned on when a welding current flows. The control device 27 can monitor the ON / OFF state of the WCR.

  The detection power source 24 is a power source for detecting that the filler wire 4 has contacted the base material 8. The contact chip 2 is electrically connected to the filler wire 4. Therefore, the detection voltage and the detection current are supplied to the filler wire 4 from the detection power supply 24 via the contact chip 2.

  The control device 27 includes a central processing unit (CPU) 30, a data input unit 32, a display unit 34, and a database 36. In the database 36, data indicating welding conditions of various welding methods obtained experimentally in advance is recorded. The CPU 30 displays a selection menu or the like on the display unit 34 and allows the user to input necessary base material information from the data input unit 32. The CPU 30 reads one data out of a plurality of data recorded in advance in the database 36 based on the base material information input to the data input unit 32 by the user.

  The CPU 30 controls the wire feeding devices 25 and 26, the power supply device 22, and the torch moving mechanism 21 based on information read from the database 36. The control device 27 may be divided and arranged in the power supply device 22 and the torch moving mechanism 21, or may be realized by a plurality of computers communicating with each other.

  FIG. 2 is a diagram for explaining a specific shape in which a welding torch and a wire feeding device are attached to a welding robot which is an example of a torch moving mechanism.

  Referring to FIG. 2, welding torch 14 is attached to the tip of the arm of torch moving mechanism 21 (hereinafter referred to as robot 21). The wire feeders 25 and 26 are attached near the joint of the arm upper arm.

  The wire feeding device 25 feeds the consumable electrode wire 3. The wire feeding device 26 feeds the filler wire 4. Each of the wire feeding devices 25 and 26 has a drive source such as a motor, and can feed the consumable electrode wire 3 and the filler wire 4 individually.

  FIG. 3 is a diagram for explaining the distance D from the base material at the tip of the filler wire. With reference to FIG. 3, when the point that contacts the base material when the filler wire 4 is fed is a point P, the distance between the point P and the tip of the filler wire 4 is a distance D. If the distance D is too short at the start of welding, the feeding start timing is too early, and the filler wire 4 collides with the base material 8 on which the molten pool is not formed. This may cause buckling or breakage of the filler wire 4. On the other hand, if the distance D is too long at the start of welding, the feed start timing of the filler wire 4 will be too late, and there will be a place where the filler wire 4 is not supplied despite the formation of the molten pool. The weld bead formed at this location becomes extremely thin, and causes welding defects such as weld cracks. Therefore, the distance D is set to an appropriate value at the start of welding.

  Whether or not the filler wire is inserted into a properly formed molten pool is determined by the distance D, the feeding speed of the filler wire, and the feeding start timing. When changing the thickness, groove shape, welding current, etc. of the base material, it is necessary to adjust the distance D, the feeding speed of the filler wire, and the feeding start timing.

  For example, when the distance D and the feeding speed of the filler wire are made constant, the feeding start timing can be adjusted to cope with changes in the base material plate thickness, groove shape, welding current, and the like.

Next, the operation at the start of welding of the welding apparatus 100 (FIG. 1) will be described in more detail.
Referring to FIG. 1 again, welding apparatus 100 performs two-wire welding by using filler wire 4 in addition to consumable electrode wire 3. Specifically, the molten pool is welded by generating an arc between the tip of the consumable electrode wire 3 and the surface of the base material 8 and feeding the filler wire 4 to the molten pool that has started to be formed by the arc heat. Grow to a suitable size (thickness and width). Thereby, welding is performed appropriately.

  A process for generating an arc between the tip of the consumable electrode wire 3 and the surface of the base material 8 at the start of welding (hereinafter referred to as “arc generation process”) is performed by applying a welding voltage from the welding power source 23 to the consumable electrode wire 3. And by supplying a welding current. Specifically, the consumable electrode wire 3 is fed in a state where a welding voltage is applied to the consumable electrode wire 3, and an arc is generated between the two after contacting the base material 8.

  When the arc is generated, the temperature of the base material 8 is increased and melted by the arc heat, and a molten pool starts to be formed. The filler wire 4 is fed to the molten pool that has started to be formed, and welding is advanced along the welding direction. Here, it takes a certain time until the molten pool is formed after the arc generation process is executed. Therefore, an appropriate delay time (hereinafter referred to as “first filler wire feeding start delay time”) from when the arc generation process is executed until the feeding of the filler wire 4 is started at the welding start scheduled position. ) Is set.

[Embodiment 1]
FIG. 4 is a waveform diagram for explaining the operation of the arc welding method of the first embodiment. FIG. 4 shows the WCR signal, the detection voltage Vt1 between the filler wire 4 and the base material 8, and the feeding speed Fw1 of the filler wire 4 from the top.

  Referring to FIGS. 1 and 4, at times t <b> 0 to t <b> 1, when the WCR signal is OFF and the detection voltage Vt <b> 1 is applied to the filler wire 4, the filler wire 4 is fed to the wire feeding device 26. Is done by. During this period, the feeding speed Fw1> 0.

  When the filler wire 4 contacts the base material 8 at time t1, a detection current flows and a decrease in the detection voltage Vt1 is detected. As a result, the control device 27 causes the wire feeding device 26 to stop feeding and causes retraction (feeding in the reverse direction) from time t2. During this period, the feeding speed Fw1 <0. As a result of the reverse feeding, the detection voltage Vt1 rises again due to the tip of the filler wire 4 being separated from the base material 8 at time t3.

  Then, the reverse feeding of the filler wire 4 is performed between the times t2 and t4, and the distance determined by the reverse feeding speed and time is the distance D shown in FIG.

  FIG. 5 is a diagram schematically showing the state of the welding torch and the wire immediately after the arc is generated at time t5 in FIG. 4 and 5, at time t5, after the supply of the consumable electrode wire 3 and the application of the welding voltage, the arc is generated and the welding current flows, so that the WCR signal is turned on.

  FIG. 6 is a diagram schematically showing the state of the welding torch and the wire when the filler wire starts to be fed at time t6 in FIG. Referring to FIGS. 4 and 6, at time t <b> 6, the arc length is longer than that shown in FIG. 5 and the size of the molten pool is increased due to heat input to the base material after the arc is generated. However, the growth of the molten pool is still insufficient.

  FIG. 7 is a diagram schematically showing the state of the welding torch and the wire in a state where the formation of the molten pool is completed at time t7 in FIG. Referring to FIGS. 4 and 7, at time t7, the molten pool has grown to an appropriate size, and at the same timing, the tip of the filler wire is fed by a distance D and inserted into the molten pool.

  At time t6 after the first filler wire feeding start delay time TD from time t5, feeding of the filler wire 4 is started, and at time t7, the detected voltage Vt is lowered by the filler wire 4 coming into contact with the molten pool. . At time t7, the base material is in a state where the formation of an appropriate molten pool has been completed. Thereafter, welding is performed while this arc state is maintained.

Times t5 to t7 are the time from the start of the arc to the completion of the formation of the molten pool, that is, the molten pool formation time T1. The difference (T1-TD) between the molten pool formation time T1 and the feed start delay time TD indicates the time during which the filler wire runs idle. Between this value and the filler wire feed speed Fw1 and the distance D in FIG. 3, the relationship shown in the following equation (1) is established.
(T1-TD) × Fw1 = D (1)
As the control parameter of the welding apparatus, the feed start delay time TD is easier to use directly, so the feed start delay time TD may be calculated by the following equation (2).
TD = T1-D / Fw1 (2)
FIG. 8 is a flowchart for explaining the welding condition reading operation at the start of welding executed in the first embodiment.

  Referring to FIGS. 1 and 8, first, in step S <b> 1, CPU 30 displays a menu or the like on display unit 34, and inputs information such as welding method, wire material, wire diameter, and gas type from data input unit 32. Prompt the user to enter and accept the input.

  The data input at this time includes, for example, a welding method (short-circuit welding, pulse welding, etc.), a base material (soft steel, stainless steel, etc.), a wire material (= base material), a wire diameter, and a gas (MAG 80% Ar, Information such as 20% CO2).

  Subsequently, in step S2, the CPU 30 selects a database to be used from among a plurality of databases stored in the database 36 based on the data input in step S1.

  In step S3, the CPU 30 displays a menu or the like on the display unit 34, prompts the user to input information on base material data (plate thickness, groove shape, etc.) and welded finish shape (eg, leg length), and accepts the input. .

  FIG. 9 is a diagram for explaining the database selected in step S2 and used in step S3. FIG. 9 shows an example of a database. However, when the welding method or the like is changed, the number and contents of input data and welding conditions are changed as appropriate. Referring to FIG. 9, data number 1 includes, as input data, welding conditions (current I (1), voltage corresponding to plate thickness TH (1), groove shape G (1), leg length L (1). V (1), welding speed F (1)) and weld pool formation time T1 (1) are recorded in advance. Data No. 2 includes, as input data, welding conditions (current I (2), voltage V (2), welding speed corresponding to plate thickness TH (2), groove shape G (2), leg length L (2). F (2)) and molten pool formation time T1 (2) are recorded in advance.

  In step S4 in FIG. 8, the CPU 30 collates the input data portion of the database shown in FIG. 9 with the data input from the user in step S3, and the corresponding welding conditions (current I, voltage V, welding speed) from the database. F) is acquired, and a molten pool formation time T1 is acquired in step S5.

  In step S6, the feeding start delay time TD is calculated. The feed start delay time TD can be calculated using, for example, the equation (2) described above. In the first embodiment, the molten pool formation time T1 is stored in the database as shown in FIG. 9. However, instead of the molten pool formation time T1, the feeding speed Fw1 and the feeding start delay time TD are stored in the database. It may be stored in the memory and read out for use.

  Subsequently, an arc generation process is performed in step S7, and in step S8, the CPU 30 applies the determined control condition of the filler wire 4 to start welding.

  As described above, according to the first embodiment, in the welding method using the filler wire, when the base material or the shape of the workpiece is changed, the control parameters for the filler wire are determined by trial and error. This eliminates the need to improve work efficiency and stabilize welding quality.

[Embodiment 2]
The arc generation process is normally performed at a position where welding is to be started (welding start position). However, when this arc generation process is performed, for example, if a non-metallic substance such as slag exists on the surface of the base material, an arc may not be generated. The second embodiment relates to arc start control when retrying arc generation in such a case.

  Referring to FIG. 1 again, when no arc is generated at the welding start scheduled position, welding apparatus 100 executes the arc generation process at a position different from the welding start scheduled position (hereinafter referred to as “arc generation processing retry position”). To do. The arc generation processing retry position can be, for example, any position on the welding line (welding line) that advances from the scheduled welding start position in the welding direction. Of course, the arc generation processing retry position may be a position different from that on the weld line. Moreover, although an arc may not generate | occur | produce also in an arc generation process retry position, in that case, the welding apparatus 100 can perform an arc generation process in another arc generation process retry position. That is, the welding apparatus 100 moves the tip of the consumable electrode wire 3 from the planned welding start position while trying to generate an arc, and generates an arc at any of the arc generation processing retry positions.

  When an arc is generated at the arc generation processing retry position, the welding apparatus 100 moves the welding arc to a planned welding start position while maintaining the generated arc. To move while maintaining the arc, the consumable electrode wire 3 is moved while keeping the distance between the consumable electrode wire 3 and the base material 8 appropriately. The consumable electrode wire 3 moves together with the filler wire 4 by the welding torch 14.

  During this movement, the welding apparatus 100 does not feed the filler wire 4. Even if an arc is generated between the consumable electrode wire and the base material, if the filler wire is not fed, even if a molten pool starts to be formed by the arc heat, the growth is suppressed. Thereby, it is possible to prevent an undesired weld bead from being formed between the position where the arc is generated and the planned welding start position.

  After the arc moves to the planned welding start position, feeding of the filler wire 4 is started, and welding is advanced along the welding direction. Here, it takes a certain time until the weld pool is formed after the arc reaches the welding start scheduled position. Therefore, a delay time (hereinafter referred to as “second filler wire feed start delay” is also from the time when the arc generated at the arc generation processing retry position reaches the welding start scheduled position until the filler wire 4 starts to be fed. It is preferable to provide time).

  In order to improve the welding quality, it is more preferable to feed the filler wire 4 at a relatively low speed at the start of feeding, and then gradually increase the speed to finally reach a constant speed. This change is the same for the welding speed, welding current, and welding voltage. Therefore, each change is appropriately controlled so that the feeding speed, the welding speed, the welding current, and the welding voltage of the filler wire 4 are constant (hereinafter, sometimes referred to as “welding steady state”). .

  When an arc is generated at the arc generation processing retry position, the base material is heated by the arc heat until the arc moves to the welding start scheduled position. That is, when the arc reaches the welding start scheduled position, the temperature of the base material has already risen to some extent, and the base material melts in a relatively short time and a molten pool begins to be formed. Here, it is not preferable to heat the base material for a long time by arc heat because the molten pool becomes too large. Therefore, the second filler wire feed start delay time is set shorter than the first filler wire feed start delay time (feed start delay time when retry is not performed) described in the first embodiment. As a result, an appropriately sized molten pool is formed.

  Furthermore, when an arc occurs at the retry position of the arc generation process, the time from when the arc reaches the welding start position to the steady state of welding is relatively short, so the welding speed, welding current, and welding voltage are also low. , And control to change greatly in a relatively short time.

  FIG. 10 is a diagram for explaining an arc generation retry operation at the start of welding. FIG. 10 shows a base material 8A formed by combining two metal plates in an L shape as an example of an object to be welded.

  Referring to FIGS. 1 and 10, when no arc is generated at the welding start scheduled position, consumable electrode wire 3 moves to the arc generation processing retry position ("movement 1" in FIG. 10). When the arc generation process is executed at the retry position of the arc generation process and the arc is generated, the generated arc moves to the welding start scheduled position along with the movement of the consumable electrode wire 3 ("movement 2" in FIG. 10). After the arc moves to the welding start scheduled position, the feeding of the filler wire 4 is started, and the consumable electrode wire 3 moves in the welding direction ("movement 3" in FIG. 10).

  Since the arc moves due to the movement of the consumable electrode wire 3 in the welding direction, a molten pool starts to be continuously formed in the welding direction. By feeding the filler wire 4 accordingly, an appropriately sized molten pool is continuously formed in the welding direction. When the arc is moved away or extinguished, the formed molten pool is reduced in temperature and solidifies to become a weld bead.

  FIG. 11 is a view for explaining a weld bead formed by the welding start method of the second embodiment. FIG. 11 is a cross-sectional view of a base material and a weld bead formed on the surface of the base material. As shown in FIG. 11, a weld bead having a uniform thickness is formed from the planned welding start position toward the welding direction. For this reason, according to the welding start method of Embodiment 2, the shape of a welding bead does not change with welding locations, but appropriate welding is performed.

  FIG. 12 is a flowchart for explaining control in the arc welding start method of the embodiment. The processing of this flowchart is executed by the control device 27 of FIGS.

  Referring to FIGS. 1 and 12, first, in step S <b> 11, CPU 30 reads a normal start setting for occurrence of arc from database 36. An example of the database will be described later with reference to FIG.

Then, arc generation processing is executed at the welding start scheduled position (step S12).
When an arc is generated at the welding start scheduled position (YES in step S13), feeding of the filler wire 4 is started with normal settings, and welding is performed in the welding direction (step S14). The normal setting will be described later with reference to FIG. When the welding in step S14 is started, the process of the flowchart ends (step S23).

  If no arc is generated at the welding start scheduled position (NO in step S13), the arc generation process is stopped (step S15). The arc generation process is stopped, for example, by stopping the supply of welding current and welding voltage to the consumable electrode wire 3.

  After the arc generation process is stopped in step S15, the CPU 30 reads the retry setting from the database 36 in step S16. The process of step S16 may be performed at the same time when the process of step S11 is executed. In this case, the CPU 30 first reads two types of settings, a normal start setting and a retry setting, regardless of whether or not the arc start is successful, and uses the retry setting only when necessary.

  After the arc generation process is stopped, the consumable electrode wire 3 is moved to the arc generation process retry position (step S17). The arc generation processing retry position may be an arbitrary position other than the welding start scheduled position, but the position where the arc generation has already been attempted and failed is excluded.

  After moving to the arc generation retry position in step S17, arc generation processing is executed (step S18).

  If an arc has occurred at the arc generation retry position (YES in step S19), the process proceeds to step S20. On the other hand, if no arc is generated at the arc generation retry position (NO in step S19), the welding process ends (step S23).

  In step S20, the arc generated at the arc generation retry position is maintained and moved to the welding start scheduled position. At this time, the filler wire 4 is not fed. The moving speed at this time may be a speed different from the speed at which welding is performed. From the viewpoint of productivity and the like, it is preferable that the moving speed is a speed that is high enough to prevent the arc from being maintained (that is, no arc break occurs). Thereby, the arc reaches the welding start scheduled position without performing welding by feeding the filler wire 4 (step S21).

  When the arc reaches the welding start scheduled position, the feeding of the filler wire 4 is started with retry setting, and welding is performed in the welding direction (step S22). The retry setting will be described later with reference to FIG. When the welding in step S22 is started, the process of the flowchart ends (step S23).

  FIG. 13 is a diagram showing an example of data stored in the database accessed in step S11 and step S16 in FIG. Referring to FIG. 13, data numbers 1, 2,... Are normally set data, and data numbers 1R, 2R,. Each data number includes a plate thickness TH, a groove shape G, a leg length L, and experimentally determined welding conditions 1 (current I, voltage V, welding speed F) and welding conditions 2 (feeding). The start delay time TD, the welding current increase rate β1, the welding voltage increase rate β2, and the welding speed increase rate β3) are recorded in advance.

  In data number 1, as input data, welding condition 1 (current I (1), voltage V (1), welding corresponding to plate thickness TH (1), groove shape G (1), leg length L (1) Speed F (1)) and welding condition 2 (feed start delay time TD (1), welding current increase rate β1 (1), welding voltage increase rate β2 (1), welding speed increase rate β3 (1)). It is recorded. Data No. 2 includes, as input data, welding conditions 1 (current I (2), voltage V (2), welding corresponding to plate thickness TH (2), groove shape G (2), and leg length L (2). Speed F (2)) and welding condition 2 (feed start delay time TD (2), welding current increase rate β1 (2), welding voltage increase rate β2 (2), welding speed increase rate β3 (2)). It is recorded.

  In data number 1R, as input data, welding condition 1 (current I (1), voltage V (1), welding corresponding to plate thickness TH (1), groove shape G (1), leg length L (1) Speed F (1)) and welding condition 2 (feed start delay time TDR (1), welding current increase rate β1R (1), welding voltage increase rate β2R (1), welding speed increase rate β3R (1)). It is recorded. In data number 2R, as input data, welding condition 1 (current I (2), voltage V (2), welding corresponding to plate thickness TH (2), groove shape G (2), leg length L (2) Speed F (2)) and welding condition 2 (feed start delay time TDR (2), welding current increase rate β1R (2), welding voltage increase rate β2R (2), welding speed increase rate β3R (2)). It is recorded.

  Note that the molten pool formation time T1 may be recorded as in the first embodiment, and the corresponding feed start delay time TD may be calculated based on this.

  The details of step S14 and step S22 of FIG. 12 will be described using FIG. 14 and FIG.

  FIG. 14 is a flowchart for explaining the details of the normal setting in step S14 of FIG. Referring to FIGS. 1 and 14, in the normal setting, feeding of filler wire 4 is started after a delay time in the normal setting elapses after the arc generation process is attempted (step S201). Attempting to generate an arc means, for example, that a welding voltage is applied to the consumable electrode wire 3, the consumable electrode wire 3 is fed in a state where the welding voltage is applied, and is brought into contact with the base material 8. An operation in which an arc is generated is shown. The delay time in the normal setting corresponds to the first filler wire feeding start delay time.

  When feeding of the filler wire is started in step S201, the welding current changes at an increase rate β1, the welding voltage increases at an increase rate β2, and the welding speed changes at an increase rate β3 until the welding steady state is reached. Control is performed as described above (step S202).

  When the feeding speed, the welding speed, the welding current, or the welding voltage of the filler wire 4 are constant, that is, the welding steady state is reached, the process of the flowchart ends (step S203).

  FIG. 15 is a flowchart for explaining details of the retry setting in step S22 of FIG. With reference to FIG. 1 and FIG. 15, in the retry setting, feeding of the filler wire 4 is started after a delay time in the retry setting has elapsed after the arc reaches the welding start scheduled position (step S <b> 301). The delay time in the retry setting corresponds to the above-described second filler wire feeding start delay time TDR. That is, the delay time in the retry setting in step S301 is shorter than the delay time in the normal setting in step S201 of FIG.

  When feeding of the filler wire is started in step S301, the welding current changes at an increase rate β1R, the welding voltage changes at an increase rate β2R, and the welding speed changes at an increase rate β3R until the welding steady state is reached. Control is performed (step S302). The welding current, welding voltage, and welding speed in step S302 change significantly in a shorter time than the welding current, welding voltage, and welding speed in step S202 of FIG. Therefore, the increasing rate of the welding current, welding voltage, and welding speed in step S302 is larger than the increasing rate of the welding current, welding voltage, and welding speed in step S202 of FIG.

  When the feeding speed, welding speed, welding current, or welding voltage of the filler wire 4 is constant, that is, the welding steady state is reached, the process of the flowchart ends (step S303).

FIG. 16 is a diagram for explaining an arc welding start method according to the second embodiment.
First, the change over time of each element when an arc is generated without failure at the planned welding start position will be described with a solid line in FIG.

  Referring to FIGS. 1 and 16, at the start of welding, first, the torch switch is turned on at time t10. The torch switch is a switch for causing the welding apparatus 100 to start welding. The torch switch is provided and / or controlled in the control device 27, for example. When welding is performed manually, the torch switch is provided on the welding torch 14 and is controlled by the operator.

  When the torch switch is turned on at time t <b> 10, the welding voltage V is applied to the consumable electrode wire 3. In addition, the supply of the consumable electrode wire 3 is started. However, the feeding speed of the consumable electrode wire 3 at this time is a relatively low speed (slow down speed).

  At time t20, WCR (welding current relay) is turned on. That is, the welding current I begins to flow and an arc is generated. Along with this, the welding voltage decreases. Also, a welding speed is given, and welding starts to proceed in the traveling direction.

  When an arc is generated at the welding start scheduled position, the welding current I, the welding voltage V, the welding speed F, the filler wire feeding speed Fw1, and the consumable electrode wire feeding speed Fw0 change so that the welding steady state is achieved at time t40 ( Solid line between t20 and t40). In particular, the welding current I changes such that the slope (slope) indicates the increase rate β1. The welding voltage V changes so that the slope indicates the increase rate β2. The welding speed F changes such that the slope indicates the increase rate β3.

  Further, the filler wire feed speed Fw1 increases from 0 at time t28. That is, the filler wire feeding is started at time t28. The time from time t10 to time t28 corresponds to the first filler wire feed start delay time TD.

  After time t40, welding proceeds in the welding direction with welding current I, welding voltage V, welding speed F, filler wire feed speed Fw1, and consumable electrode wire feed speed Fw0 all constant (welding steady state). .

  On the other hand, a change with time of each element when an arc is generated not at the welding start scheduled position but at the arc generation processing retry position will be described with a one-dot chain line in FIG.

  Referring to FIGS. 1 and 16, the time when the arc generated at the arc generation processing retry position reaches the welding start scheduled position corresponds to time t20. In this case, the welding current I, the welding voltage V, the welding speed F, the filler wire feeding speed Fw1, and the consumable electrode wire feeding speed Fw0 change so that the welding steady state is reached at time t30 (one point between t20 and t30). Chain line). That is, when an arc is generated at the arc generation processing retry position, the steady welding state is reached at time t30, which is a time before time t40 when the welding is started when an arc is generated at the welding start scheduled position. In particular, the welding current I changes so that the slope indicates the increase rate β1R. The welding voltage V changes so that the slope indicates the increase rate β2R. The welding speed F changes so as to indicate an inclination increase rate β3.

  Further, the filler wire feed speed Fw1 increases from 0 at time t25. That is, the filler wire feeding is started at time t25. That is, the time from time t20 to time t25 corresponds to the above-described second filler wire feed start delay time TDR.

  After time t30, welding proceeds in the welding direction with welding current I, welding voltage V, welding speed F, filler wire feed speed Fw1, and consumable electrode wire feed speed Fw0 all constant (welding steady state). .

  As shown in FIG. 16, when an arc is generated at the planned welding start position (solid line in FIG. 16), and when an arc is generated at an arc generation processing retry position that is different from the planned welding start position (in FIG. 16). In the alternate long and short dash line), elements such as the timing at which the filler wire feeding starts, the welding current I, the welding voltage V, and the welding speed F are different.

  Note that the welding start control may also be performed by applying the increasing rates β1 to β3 of the second embodiment to the first embodiment.

  According to the welding method and the welding apparatus of the second embodiment, even if the position where the arc is generated is not the planned welding start position, it is not desired between the position where the arc is generated and the planned welding start position. It is possible to prevent the formation of a weld bead.

  Further, by appropriately changing the filler wire feed start delay time, the welding current, the welding voltage, and the increasing rate of the welding speed in the retry setting, an appropriately sized molten pool can be formed.

  Finally, the first and second embodiments will be summarized again with reference to FIG. The arc welding method according to the first and second embodiments is an arc welding method in which the base material 8 and the filler wire 4 are melted and welded by an arc generated by an electrode (consumable electrode wire 3). In this arc welding method, base material information input from the user from a plurality of data (data No. 1, No. 2,... In FIG. 9, FIG. 13) recorded in advance in the database 36 at the start of welding. Based on (for example, plate thickness, groove shape, leg length, etc.), the processor 30 reads out one data (S5 in FIG. 8; S11 in FIG. 12), and on the basis of the read one data, The processor 30 determines the control condition of the filler wire 4, and the processor 30 executes the start of welding by applying the determined control condition of the filler wire 4 (S6-S8 in FIG. 8; S14 in FIG. 12); Is provided.

  When the user inputs the base material information, the processor determines the control condition of the filler wire, so that the user's adjustment work is greatly reduced.

  Preferably, each of a plurality of pre-recorded data includes first data (input data) indicating a base material shape and a welding finish state, and second data (melt pool) relating to filler wire control, as shown in FIG. Forming time). In the reading step, one piece of data is selected by comparing the base material information with the first data. The filler wire control condition includes a condition (feed start delay time TD) related to the filler wire feed start timing determined based on the second data.

  Preferably, in the arc welding method according to the second embodiment, as shown in FIG. 12, when the generation of the arc fails at the welding start scheduled position, the welding torch is set to the welding start scheduled position for retrying the arc generation. The processor moves the data to a different retry position (S17) and, when the generation of an arc at the welding start scheduled position fails, the processor obtains another data for retry from a plurality of data recorded in advance in the database. A step of reading (S16), a step of moving the arc generated at the retry position to the planned welding start position (S17), and a step of starting feeding the filler wire after the generated arc has moved to the planned welding start position ( S22).

  Preferably, as shown in FIG. 1, the electrode is a consumable electrode wire, and the filler wire 4 is disposed behind the consumable electrode wire 3 in the welding direction.

  When the user inputs the base material information, even if the arc generation fails and the retry is performed, the processor determines the control condition of the filler wire at the time of the arc generation retry, so that the user's adjustment work is greatly reduced. .

  A welding apparatus 100 shown in FIG. 1 is a welding apparatus that performs welding by causing a control device to execute one of the above arc welding methods.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1, 2 Contact tip, 3 Consumable electrode wire, 4 Filler wire, 8, 8A Base material, 14 Welding torch, 21 Torch moving mechanism (robot), 22 Power supply device, 23 Welding power source, 24 Detection power source, 25, 26 Wire feeding device, 27 control device, 30 CPU, 32 data input unit, 34 display unit, 36 database, 100 welding device.

Claims (5)

An arc welding method in which a base material and a filler wire are melted and welded by an arc generated by an electrode,
From the plurality of data recorded in advance in the database at the start of welding, the processor reads one data based on the base material information input from the user;
A processor determining a control condition of the filler wire based on the read one data, and applying the determined control condition of the filler wire to cause the processor to start welding ;
Each of the plurality of data includes first data indicating a base material shape and a welding finish state, and second data regarding control of the filler wire,
The reading step selects the one data by comparing the base material information with the first data,
The control condition of the filler wire is an arc welding method including a condition related to a feed start timing of the filler wire determined based on the second data . A step of moving a welding torch to a retry position different from the planned welding start position in order to retry the generation of an arc when the generation of the arc fails at the planned welding start position;
A step of reading out another data for retrying from the plurality of data when the generation of the arc at the welding start scheduled position fails,
Moving the arc generated at the retry position to the welding start scheduled position;
The arc welding method according to claim 1, further comprising a step of starting feeding the filler wire after the generated arc has moved to the welding start scheduled position. An arc welding method in which a base material and a filler wire are melted and welded by an arc generated by an electrode,
From the plurality of data recorded in advance in the database at the start of welding, the processor reads one data based on the base material information input from the user;
A processor determining a control condition of the filler wire based on the read one data, and applying the determined control condition of the filler wire to cause the processor to start welding;
A step of moving a welding torch to a retry position different from the planned welding start position in order to retry the generation of an arc when the generation of the arc fails at the planned welding start position;
A step of reading out another data for retrying from the plurality of data when the generation of the arc at the welding start scheduled position fails,
Moving the arc generated at the retry position to the welding start scheduled position;
After arc the generated is moved to the welding start position scheduled, and a step of starting the feeding of the filler wire, arc welding method. The electrode is a consumable electrode wire;
The arc welding method according to claim 1, wherein the filler wire is arranged behind the consumable electrode wire in the welding direction.   A welding apparatus for performing welding by causing a control device to execute the arc welding method according to any one of claims 1 to 4.

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