Submerged arc welding control method and submerged arc welding apparatus

Abstract

To improve the efficiency of welding operations in submerged arc welding. [Solution] In a submerged arc welding control method that controls and outputs welding voltage Vw and welding current Iw based on welding voltage setting value Vr and welding current setting value Ir, and runs an automatic carriage equipped with a welding torch to perform welding, the method sequentially switches between the initial period from time t1 to t2, the main welding period from time t2 to t3, and the crater period from time t3 to t4 based on the elapsed time from the start of welding at time t1, and controls and outputs the welding voltage Vw and welding current Iw by switching the welding voltage setting value Vr and welding current setting value Ir for each period, and the automatic carriage Rc starts running at time t11, which is one hour after the start of the initial period, and stops running at time t3, which is two hours before or after the start of the crater period.

Description

Technical Field

[0004] , , , , , , ,

[0001] The present invention relates to a submerged arc welding control method and a submerged arc welding apparatus.

Background Art

[0002] Conventionally, submerged arc welding has been known. Submerged arc welding involves spraying flux on the base material, feeding a welding wire into the flux, and generating an arc between the tip of the welding wire and the base material to perform welding. In submerged arc welding, thick plates can be welded at high efficiency by passing a large current through a thick welding wire (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In submerged arc welding, welding is typically performed by outputting welding voltage and welding current, and moving an automated trolley equipped with a welding torch. Welding is performed in stages, progressing through an initial phase, a main welding phase, and a crater phase. During the initial phase, the automated trolley is stopped at the welding start position, and welding is performed by outputting the welding voltage and welding current based on the initial voltage and current settings. During the main welding phase, the automated trolley moves along the welding line, and welding is performed by outputting the welding voltage and welding current based on the main voltage and current settings. During the crater phase, the automated trolley is stopped at the welding end position, and welding is performed by outputting the welding voltage and welding current based on the crater voltage and crater current settings. In conventional submerged arc welding, the welding voltage and welding current settings for each phase, as well as the movement / stopping of the automated trolley, are all manually performed by the welder. This results in the problem of time-consuming welding work in conventional submerged arc welding.

[0005] Therefore, the present invention aims to provide, for example, a submerged arc welding control method and a submerged arc welding apparatus that can improve the efficiency of welding operations. [Means for solving the problem]

[0006] A submerged arc welding control method provided by a first aspect of the present invention is a submerged arc welding control method that controls and outputs a welding voltage and a welding current based on a welding voltage setting value and a welding current setting value, and runs an automatic carriage equipped with a welding torch to perform welding, characterized in that the method sequentially switches between an initial period, a main welding period and a crater period based on the elapsed time from the start of welding, switches the welding voltage setting value and the welding current setting value for each of the periods to control and output the welding voltage and the welding current, and the automatic carriage starts running at a point one hour after the start of the initial period and stops running at a point two hours before or after the start of the crater period.

[0007] As an example, the submerged arc welding control method of the present invention is characterized by setting an initial time, a main welding time, and a crater time, transitioning to the main welding period when the elapsed time reaches the initial time, transitioning to the crater period when the elapsed time reaches (the initial time + the main welding time), and ending the crater period when the elapsed time reaches (the initial time + the main welding time + the crater time).

[0008] For example, the submerged arc welding control method of the present invention is characterized by setting the welding speed and welding length, and setting the main welding time by calculating (the welding length / the welding speed).

[0009] As an example, the submerged arc welding control method of the present invention comprises a test welding mode and an actual welding mode, wherein in the test welding mode, the welding voltage setting value and the welding current setting value are adjusted during each of the initial period, the main welding period, and the crater period, the welding voltage setting value and the welding current setting value at the end of each period are stored for each period, and a test welding is performed; and in the actual welding mode, the welding voltage and the welding current are controlled and output based on the welding voltage setting value and the welding current setting value stored for each period, and actual welding is performed.

[0010] For example, the submerged arc welding control method of the present invention is characterized in that, when in the test welding mode, it notifies the user that it is within the specified period, and the welder manually adjusts the welding voltage set value and the welding current set value for each specified period.

[0011] A submerged arc welding apparatus provided by a second aspect of the present invention controls and outputs a welding voltage and welding current based on a welding voltage setting and a welding current setting, and operates an automated trolley equipped with a welding torch to perform welding, characterized in that the apparatus sequentially switches between an initial period, a main welding period, and a crater period based on the elapsed time from the start of welding, controls and outputs the welding voltage and welding current by switching the welding voltage setting and the welding current setting for each of the periods, and the automated trolley starts moving at a point one hour after the start of the initial period, and stops moving at a point two hours before or after the start of the crater period. [Effects of the Invention]

[0012] According to the above configuration, for example, with respect to a submerged arc welding control method and a submerged arc welding apparatus, welding operations can be made more efficient. [Brief explanation of the drawing]

[0013] [Figure 1] This is a block diagram of a submerged arc welding apparatus according to an embodiment of the present invention. [Figure 2] Figure 1 shows a timing chart of each signal in a submerged arc welding apparatus illustrating a submerged arc welding control method according to an embodiment of the present invention. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the drawings.

[0015] Figure 1 is a block diagram of a submerged arc welding apparatus according to an embodiment of the present invention. Each block will be described below with reference to this figure.

[0016] The welding mode selection circuit MS is provided on the front panel of the welding power source PS. It is a circuit for the welder to switch between the test welding mode and the actual welding mode, and outputs a welding mode signal Ms that becomes high level when the test welding mode is selected and low level when the actual welding mode is selected.

[0017] The welding voltage setting circuit VR is provided on the front panel of the welding power source PS or the like, and outputs a welding voltage setting signal Vr manually adjusted by the welder. The welding current setting circuit IR is provided on the front panel of the welding power source PS or the like, and outputs a welding current setting signal Ir manually adjusted by the welder.

[0018] The welding start circuit ST includes a push button. Taking the period discrimination signal Sr described later as an input, it outputs a welding start signal St that becomes high level when the welder turns it on, and then returns to low level when the period discrimination signal Sr changes from 3 to 0.

[0019] The energization discrimination circuit CD outputs an energization discrimination signal Cd that becomes high level when it discriminates the energization of the welding current Iw.

[0020] The initial time setting circuit TSR is a touch panel provided on the front panel of the welding power source PS, etc., and outputs an initial time setting signal Tsr input by the welder. The welder operates the touch panel to set an initial time setting signal Tsr such as 5 seconds or 10 seconds.

[0021] The welding speed setting circuit WSR is a touch panel provided on the front panel of the welding power source PS, etc., and outputs a welding speed setting signal Wsr input by the welder. The welder operates the touch panel to set a welding speed setting signal Wsr such as 20 cm / min or 30 cm / min.

[0022] The welding length setting circuit LR is a touch panel or the like provided on the front panel of the welding power source PS, and outputs a welding length setting signal Lr which is the length of the welding line input by the welder. The welder operates the touch panel to set the welding length setting signal Lr such as 300 cm or 500 cm.

[0023] This welding time setting circuit THR takes the above-mentioned welding speed setting signal Wsr and the above-mentioned welding length setting signal Lr as inputs, performs the calculation of the welding time setting signal Thr = Lr / Wsr, and outputs the result. For example, when Lr = 300 cm and Wsr = 30 cm / min, Thr = 300 / 30 = 10 minutes. The welder may directly set this welding time setting signal Thr.

[0024] The crater time setting circuit TKR is a touch panel or the like provided on the front panel of the welding power source PS, and outputs a crater time setting signal Tkr input by the welder. The welder operates the touch panel to set the crater time setting signal Tkr such as 3 seconds or 5 seconds.

[0025] The period discrimination circuit SR takes the above-mentioned energization discrimination signal Cd, the above-mentioned initial time setting signal Tsr, the above-mentioned welding time setting signal Thr, and the above-mentioned crater time setting signal Tkr as inputs, and performs the following processing based on the elapsed time from the start point of welding when the energization discrimination signal Cd changes to the High level, and outputs a period discrimination signal Sr. 1) When the energization discrimination signal Cd changes to the High level, the period discrimination signal Sr is set from 0 to 1 (initial period) and output. 2) When the elapsed time reaches the value of the initial time setting signal Tsr, the period discrimination signal Sr = 2 (main welding period) is output. 3) When the elapsed time reaches the value of (initial time setting signal Tsr + welding time setting signal Thr), the period discrimination signal Sr = 3 (crater period) is output. 4) When the elapsed time reaches the value of (initial time setting signal Tsr + welding time setting signal Thr + crater time setting signal Tkr), the period discrimination signal Sr = 0 (welding end) is output.

[0026] The driving control circuit RC takes the above-mentioned period discrimination signal Sr as input, performs the following processing, and outputs a driving control signal Rc. 1) When the elapsed time from the moment the value of the period discrimination signal Sr changes to 1 (initial period) reaches a predetermined first time T1, the driving control signal Rc = High level (start of driving) is output. Here, the first time T1 is a positive value and may be set to the value of the initial time setting signal Tsr. 2) When the elapsed time from the point in time when the value of the period discrimination signal Sr changes to 2 (main welding period) reaches the value of (main welding time setting signal Thr + predetermined second time T2), a travel control signal Rc = Low level (travel stop) is output. Here, the second time T2 can be a negative value, 0, or a positive value.

[0027] The welding condition memory circuit WM takes the above-mentioned welding mode signal Ms, period discrimination signal Sr, welding voltage setting signal Vr, and welding current setting signal Ir as inputs. When the welding mode signal Ms is a high-level test welding mode, it performs the following processing and stores the values ​​of the welding voltage setting signal Vr and welding current setting signal Ir in combination with the period discrimination signal Sr as the welding condition memory signal Wm. 1) When the period discrimination signal Sr counts up from 0 to 1 to 2 to 3, this fact is notified by sound, light, display on a screen, etc. 2) During each period, the welder adjusts the welding voltage setting signal Vr and the welding current setting signal Ir. 3) When the period discrimination signal Sr changes from 1 → 2 → 3 → 0, the values ​​of the welding voltage setting signal Vr and welding current setting signal Ir at that time are stored in combination with the period discrimination signal Sr of the previous period. For example, when Sr=1 (initial period) changes to Sr=2 (main welding period), the values ​​of the welding voltage setting signal Vr and welding current setting signal Ir at that time are stored in combination with the value of the period discrimination signal Sr of the previous period as Wm=(Sr=1,Vr,Ir).

[0028] The welding condition setting circuit WR takes the above-mentioned welding mode signal Ms, period discrimination signal Sr, and welding condition storage signal Wm as inputs. When the welding mode signal Ms is at a low level (actual welding mode), it outputs the values ​​of the welding voltage setting signal Vr and welding current setting signal Ir stored in the welding condition storage signal Wm, corresponding to the value of the period discrimination signal Sr.

[0029] The welding power supply PS takes the above-mentioned welding start signal St, welding voltage setting signal Vr, and welding current setting signal Ir as inputs. While the welding start signal St is at a high level, it takes a commercial AC power supply such as 3-phase 200V (not shown in the diagram) as input and performs output control such as inverter control based on the welding voltage setting signal Vr and welding current setting signal Ir to output the welding voltage Vw and welding current Iw. It also outputs a feed control signal Fc to the feeder WF based on the welding current setting signal Ir. Since the welding power supply PS is constant voltage controlled, the welding voltage Vw is controlled to the value of the welding voltage control setting signal Vr. The welding power supply PS may also be constant current controlled. In addition, the welding voltage Vw and welding current Iw may be DC or AC.

[0030] The feeder WF is equipped with a feed motor and, taking the above-mentioned feed control signal Fc as input, feeds the welding wire 1 through the welding torch 4 to the base material 2. The feeding speed of the welding wire 1 corresponds to the value of the welding current setting signal Ir.

[0031] The welding torch 4 guides the welding wire 1 into the base material 2 and supplies power to the welding wire 1 via a power supply tip (not shown in the figure).

[0032] The flux sprayer 5 sprays flux onto the welding line.

[0033] The automated trolley AT receives the above-mentioned travel control signal Rc and welding speed setting signal Wsr as inputs, and is equipped with the above-mentioned welding torch 4 and flux sprayer 5. The flux sprayer 5 sprays flux, and while the travel control signal Rc is at a high level, the trolley travels at the speed set by the welding speed setting signal Wsr so that the tip of the welding torch 4 is aligned with the weld line, and stops traveling when the travel control signal Rc is at a low level. The automated trolley AT starts traveling at a point after the first hour T1 from the start of the initial period, and stops traveling at a point before or after the second hour T2 from the start of the crater period.

[0034] A groove is provided in the base material 2. A welding voltage Vw is applied between the welding wire 1 and the base material 2, and a welding current Iw is passed through, generating an arc 3 while covered with flux.

[0035] Figure 2 is a timing chart of each signal in the submerged arc welding apparatus shown in Figure 1, illustrating a submerged arc welding control method according to an embodiment of the present invention. Figure (A) shows the time variation of the welding start signal St, Figure (B) shows the time variation of the energization discrimination signal Cd, Figure (C) shows the time variation of the welding voltage setting signal Vr, Figure (D) shows the time variation of the welding current setting signal Ir, Figure (E) shows the time variation of the welding voltage Vw, Figure (F) shows the time variation of the welding current Iw, and Figure (G) shows the time variation of the travel control signal Rc. The operation of each signal will be described below with reference to the figure.

[0036] [Explanation of Test Welding Operation] The welder sets up the base material 2 and moves the automatic trolley AT in Figure 1 so that the tip of the welding torch 4 is at the welding start position. When the welder selects the test welding mode using the welding mode selection circuit MS in Figure 1, a high-level welding mode signal Ms is output, and the submerged arc welding apparatus enters test welding mode. When the welder inputs the initial time using the initial time setting circuit TSR in Figure 1, the initial time setting signal Tsr is set. When the welder inputs the welding speed using the welding speed setting circuit WSR in Figure 1, the welding speed setting signal Wsr is set. The value of this welding speed setting signal Wsr is the travel speed of the automatic trolley AT. When the welder inputs the length of the weld line using the welding length setting circuit LR in Figure 1, the welding length setting signal Lr is set. The main welding time setting circuit THR in Figure 1 performs the calculation (welding length setting signal Lr / welding speed setting signal Wsr) to set the main welding time setting signal Thr. When a welder inputs the crater time using the crater time setting circuit TKR shown in Figure 1, the crater time setting signal Tkr is set.

[0037] [Explanation of operation during the initial period] At time t1, when the welder turns on the push button of the welding start circuit ST in Figure 1, the welding start signal St changes to a high level, as shown in Figure (A). In response, the welding power supply PS starts up, the welding wire 1 is fed, and the arc 3 is generated. As a result, at time t1, the welding voltage Vw becomes an arc voltage value of several tens of volts, as shown in Figure (E). As shown in Figure (F), the welding current Iw also starts to flow, so the current flow determination signal Cd becomes high, as shown in Figure (B). As a result, the period determination signal Sr changes from 0 to 1, and the initial period begins. The length of the initial period from time t1 to t2 is set by the initial time setting signal Tsr mentioned above. Since the period determination signal Sr has been counted up, this is indicated by sound, light, display on a screen, etc. Because the welder adjusted the value of the welding voltage setting signal Vr shown in Figure (C) to Vr1, the welding voltage Vw shown in Figure (E) is controlled to a constant voltage of Vr1. Furthermore, because the welder adjusted the value of the welding current setting signal Ir shown in Figure (D) to Ir1, the welding current Iw shown in Figure (F) becomes the value of Ir1 via the feed speed. The welding voltage Vw and welding current Iw have waveforms that fluctuate up and down with short periods. At time t11, when the elapsed time from the start of welding, when the energization discrimination signal Cd changed to a high level at time t1, reaches a predetermined first time T1, the travel control signal Rc becomes high level, as shown in Figure (G), and the automatic trolley AT starts moving. The travel speed is the value of the welding speed setting signal Wsr mentioned above. In this figure, since the first time T1 is smaller than the value of the initial time setting signal Tsr, time t11 is earlier than time t2. When both values ​​are equal, time t11 is the same time as time t2. When the first time T1 is greater than the value of the initial time setting signal Tsr, time t11 is a later time than time t2.

[0038] [Explanation of operations during the main welding period] At time t2, when the elapsed time from time t1 reaches the value of the initial time setting signal Tsr, the period discrimination signal Sr is counted up from 1 to 2, and the welding period begins. The length of the welding period from time t2 to t3 is set by the welding time setting signal Thr mentioned above. At the same time, the welding voltage setting signal Vr=Vr1 and the welding current setting signal Ir=Ir1 at time t2 are combined with the period discrimination signal Sr=1 and stored as the welding condition storage signal Wm=(1,Vr1,Ir1) in Figure 1. Since the period discrimination signal Sr has been counted up, this is indicated by sound, light, display, etc. At time t21, a short time after time t2, the welder adjusts the value of the welding voltage setting signal Vr shown in Figure (C) to increase it to Vr2 in response to the above notification, and the welding voltage Vw shown in Figure (E) is controlled to a constant voltage of Vr2. Furthermore, at time t21, the welder adjusted the value of the welding current setting signal Ir shown in Figure (D) to increase it to Ir2, so the value of the welding current Iw shown in Figure (F) becomes the value of Ir2 via the feed rate. The welding voltage Vw and welding current Iw become waveforms that fluctuate up and down with short periods.

[0039] [Explanation of operation during the crater period] At time t3, when the elapsed time from time t1 reaches the value of (initial time setting signal Tsr + main welding time setting signal Thr), the period discrimination signal Sr is counted up from 2 to 3, and the crater period begins. The length of the crater period from time t3 to t4 is set by the crater time setting signal Tkr mentioned above. At the same time, the welding voltage setting signal Vr=Vr2 and welding current setting signal Ir=Ir2 at time t3 are combined with the period discrimination signal Sr=2 and stored as the welding condition memory signal Wm=(2,Vr2,Ir2). Since the period discrimination signal Sr has been counted up, this is indicated by sound, light, display, etc. At time t31, a short time after time t3, as shown in Figure (C), the welding operator adjusts the value of the welding voltage setting signal Vr to decrease to Vr3 in response to the above notification, so the welding voltage Vw is controlled to a constant voltage of Vr3. At time t31, as shown in Figure (D), the welder adjusted the value of the welding current setting signal Ir to decrease to Ir3, so the value of the welding current Iw becomes the value of Ir3 via the feed rate. The welding voltage Vw and welding current Iw have waveforms that fluctuate up and down with short periods. At time t3, when the elapsed time from the point at time t2 when the period discrimination signal Sr changed to 2 (main welding period) reaches the value of (main welding time setting signal Thr + predetermined second time T2), as shown in Figure (G), the travel control signal Rc becomes Low level and the automatic trolley AT stops moving. In this figure, since the second time T2 = 0, the stopping time is the same as time t3. When the second time T2 < 0, the stopping time is earlier than time t3. When the second time T2 > 0, the stopping time is later than time t3.

[0040] At time t4, when the elapsed time from time t1 reaches the value of (initial time setting signal Tsr + main welding time setting signal Thr + crater time setting signal Tkr), the period discrimination signal Sr changes from 3 to 0, and welding ends. In response to this, as shown in Figure (A), the welding start signal St becomes low, and the welding power supply PS in Figure 1 stops outputting. As a result, as shown in Figure (E), the welding voltage Vw becomes 0V, and as shown in Figure (F), the feeding of the welding wire stops and the welding current Iw becomes 0A. Thus, the test welding is completed. At the same time, the welding voltage setting signal Vr=Vr3 and the welding current setting signal Ir=Ir3 at time t4 are combined with the period discrimination signal Sr=3 and stored as the welding condition storage signal Wm=(3,Vr3,Ir3).

[0041] [Explanation of the welding process during actual work] The welder sets up the base material 2 and moves the automatic trolley AT shown in Figure 1 so that the tip of the welding torch 4 is at the welding start position. When the welder selects the actual welding mode using the welding mode selection circuit MS shown in Figure 1, a low-level welding mode signal Ms is output, and the submerged arc welding device enters the actual welding mode.

[0042] When the welder turns on the push button of the welding start circuit ST in Figure 1, welding begins. Then, as described above, based on the elapsed time from the start of welding, the system is automatically switched sequentially to the initial period from time t1 to t2, the main welding period from time t2 to t3, and the crater period from time t3 to t4. In each period, the welding voltage Vw and welding current Iw are controlled and output based on the welding voltage setting signal Vr and welding current setting signal Ir for each period, which are stored in the welding condition memory signal Wm in Figure 1. That is, the values ​​of the welding voltage setting signal Vr and welding current setting signal Ir are Wm=(Sr=1,Vr1,Ir1) during the initial period, Wm=(Sr=2,Vr2,Ir2) during the main welding period, and Wm=(Sr=3,Vr3,Ir3) during the crater period. Furthermore, the automatic trolley in Figure 1 starts moving at a point one hour T1 after the start of the initial period, and stops moving at a point one hour T2 before or after the start of the crater period. Therefore, in this embodiment, by simply turning on the push button for starting welding, the switching of the welding voltage setting signal Vr and welding current setting signal Ir for each period (initial period, main welding period, and crater period) and the switching of the automatic trolley AT to move / stop can be automatically synchronized, thereby improving the efficiency of welding work.

[0043] The effects of this embodiment will be described below. According to this embodiment, in a submerged arc welding control method in which welding is performed by controlling and outputting welding voltage and welding current based on welding voltage setting values ​​and welding current setting values ​​and driving an automatic carriage equipped with a welding torch, the system sequentially switches between the initial period, the main welding period, and the crater period based on the elapsed time from the start of welding, and controls and outputs the welding voltage and welding current by switching the welding voltage setting values ​​and welding current setting values ​​for each period. The automatic carriage starts moving only one hour after the start of the initial period and stops moving only two hours before or after the start of the crater period. In submerged arc welding, it is common to output welding voltage and welding current and drive an automatic carriage equipped with a welding torch to perform welding. Welding is performed by sequentially transitioning through the initial period, the main welding period, and the crater period. In conventional submerged arc welding, the welding operator manually switches the welding voltage setting values ​​and welding current setting values ​​for each period and switches the automatic carriage from moving to stopping. For this reason, conventional submerged arc welding has the problem of being time-consuming. In contrast, in this embodiment, the switching of welding voltage and welding current settings for each period and the switching of the automatic trolley's movement / stopping can be automatically synchronized, so the welding work can be made more efficient.

[0044] More preferably, according to this embodiment, an initial time, a main welding time, and a crater time are set. When the elapsed time reaches the initial time, the process transitions to the main welding period. When the elapsed time reaches (initial time + main welding time), the process transitions to the crater period. When the elapsed time reaches (initial time + main welding time + crater time), the crater period ends. In this way, the switching between the initial period, the main welding period, and the crater period can be performed automatically based on the elapsed time from the start of welding, making it easy to do without adding any special sensors or the like.

[0045] More preferably, according to this embodiment, the welding speed and welding length are set, and the actual welding time is set by calculating (welding length / welding speed). In this way, the actual welding time can be set by calculation, thus eliminating the need to measure the actual welding time by conducting test runs.

[0046] More preferably, according to this embodiment, a test welding mode and an actual welding mode are provided. In test welding mode, the welding voltage setting value and welding current setting value are adjusted during each of the initial period, main welding period, and crater period, and the welding voltage setting value and welding current setting value at the end of each period are stored for each period and test welding is performed. In actual welding mode, the welding voltage and welding current are controlled and output based on the welding voltage setting value and welding current setting value stored for each period to perform actual welding. In submerged arc welding, it is necessary to process and set a groove in the thick plate, so the preparation before welding is time-consuming. For this reason, in conventional submerged arc welding, there is a problem that it takes a lot of time to repeat test welding in order to set the welding voltage setting value and welding current setting value to the appropriate value. In this embodiment, the welding voltage setting value and welding current setting value are adjusted for each of the initial period, main welding period, and crater period during a single test welding, and the adjusted welding voltage setting value and welding current setting value for each period are stored and test welding is performed. Then, actual welding is performed based on the welding voltage setting value and welding current setting value stored for each period. In this way, the welding voltage and welding current settings for each period in a single test weld can be optimized, thus streamlining the setting of welding conditions through test welding.

[0047] More preferably, according to this embodiment, when in test welding mode, the system notifies the user that each period is occurring, and the welder manually adjusts the welding voltage and welding current settings for each period. In this embodiment, the start of each period is notified by sound, light, display, etc., so the welder can smoothly adjust the welding voltage and welding current settings for each period upon receiving the notification.

[0048] Furthermore, according to this embodiment, the submerged arc welding apparatus sequentially switches between the initial period, the main welding period, and the crater period based on the elapsed time from the start of welding, and controls and outputs the welding voltage and welding current by switching the welding voltage setting value and welding current setting value for each period. The automatic trolley starts moving at a point one hour after the start of the initial period, and stops moving at a point two hours before or after the start of the crater period. The submerged arc welding apparatus according to this embodiment achieves the above-mentioned effects. [Explanation of Symbols]

[0049] 1: Welding wire, 2: Base material, 3: Arc, 4: Welding torch, 5: Flux sprayer, AT: Automatic trolley, CD: Power supply detection circuit, Cd: Power supply detection signal, IR: Welding current setting circuit, Ir: Welding current setting signal, Iw: Welding current, LR: Welding length setting circuit, Lr: Welding length setting signal, MS: Welding mode selection circuit, Ms: Welding mode signal, PS: Welding power supply, RC: Travel control circuit, Rc: Travel control signal, SR: Period detection circuit, Sr: Period detection signal, ST: Welding start circuit, St: Welding Welding start signal, T1: 1st time, T2: 2nd time, THR: Main welding time setting circuit, Thr: Main welding time setting signal, TKR: Crater time setting circuit, Tkr: Crater time setting signal, TSR: Initial time setting circuit, Tsr: Initial time setting signal, VR: Welding voltage setting circuit, Vr: Welding voltage setting signal, Vw: Welding voltage, WF: Feeder, WM: Welding condition memory circuit, Wm: Welding condition memory signal, WR: Welding condition setting circuit, WSR: Welding speed setting circuit, Wsr: Welding speed setting signal

Claims

1. In a submerged arc welding control method that controls and outputs welding voltage and welding current based on welding voltage setting values ​​and welding current setting values, and operates an automated trolley equipped with a welding torch to perform welding, A submerged arc welding control method characterized by sequentially switching between an initial period, a main welding period, and a crater period based on the elapsed time from the start of welding, switching the welding voltage setting value and the welding current setting value for each of the periods to control and output the welding voltage and the welding current, and having the automatic trolley start moving at a point one hour after the start of the initial period, and stopping moving at a point two hours before or after the start of the crater period.

2. The submerged arc welding control method according to claim 1, characterized in that an initial time, a main welding time, and a crater time are set, the process transitions to the main welding period when the elapsed time reaches the initial time, the process transitions to the crater period when the elapsed time reaches (initial time + main welding time), and the crater period ends when the elapsed time reaches (initial time + main welding time + crater time).

3. The submerged arc welding control method according to claim 2, characterized in that the welding speed and welding length are set, and the main welding time is set by calculating (the welding length / the welding speed).

4. A submerged arc welding control method according to any one of claims 1 to 3, comprising a test welding mode and an actual welding mode, wherein in the test welding mode, the welding voltage setting value and the welding current setting value are adjusted during each of the initial period, the actual welding period, and the crater period, the welding voltage setting value and the welding current setting value at the end of each period are stored for each period, and a test welding is performed; and in the actual welding mode, the welding voltage and the welding current are controlled and output based on the welding voltage setting value and the welding current setting value stored for each period to perform actual welding.

5. The submerged arc welding control method according to claim 4, characterized in that, when in the test welding mode, the system notifies that it is within the period, and the welder manually adjusts the welding voltage setting value and the welding current setting value for each period.

6. In a submerged arc welding system that controls and outputs welding voltage and welding current based on welding voltage setting values ​​and welding current setting values, and operates an automated trolley equipped with a welding torch to perform welding, A submerged arc welding apparatus characterized by sequentially switching between an initial period, a main welding period, and a crater period based on the elapsed time from the start of welding, controlling and outputting the welding voltage and welding current by switching the welding voltage setting value and the welding current setting value for each of the periods, and having the automatic carriage start moving at a point one hour after the start of the initial period, and stopping moving at a point two hours before or after the start of the crater period.

Images