JP2010017738A - Setting method of welding condition of mag pulse welding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate setting of welding conditions when wire for CO<SB>2</SB>gas arc welding is used instead of wire for pulse arc welding in MAG pulse welding. <P>SOLUTION: In a setting method of the welding conditions of the MAG pulse welding, which is carried out by feeding welding wire 1 at a preliminarily determined feeding speed Fr, applying a peak current Ipr during a peak period Tpr, applying a base current Ibr during a base period, and controlling the base period to allow a welding voltage average value Vd to be equal to a welding voltage setting value Vr, a wire type selection switch ST for selecting a wire mode for CO<SB>2</SB>gas arc welding is arranged, and when this mode is selected, the peak period Tpr is made longer by a predetermined value ΔTp, while the welding voltage setting value Vr is increased by a predetermined value ΔVr, and the feeding speed Fr is made faster by a predetermined value ΔFr. Accordingly, the welding conditions suitable for the wire for CO<SB>2</SB>gas arc welding are automatically set only by selecting the switch ST. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a welding condition setting method of mag pulse welding that can simplify the setting of welding conditions in mag pulse welding using a carbon dioxide arc welding wire.

  In pulse arc welding of steel materials, it is common to use a mixed gas of argon gas and carbon dioxide as a shielding gas, which is called mag pulse welding. A pulse arc welding wire (JIS standard Z3312: 1999, YGW15 and YGW17) is used for this mag pulse welding. In this pulse arc welding wire, the composition component is optimized so that the droplets are stably transferred in synchronization with the peak current. Hereinafter, the welding condition setting method of the mag pulse welding in a prior art is demonstrated (for example, refer patent document 1, 2 grade | etc.,).

  FIG. 2 is a current and voltage waveform diagram in mag pulse welding. FIG. 2A shows a welding current Iw for energizing an arc, and FIG. 2B shows a welding voltage Vw applied between the welding wire and the base material. Hereinafter, a description will be given with reference to FIG.

  During the predetermined peak period Tp, as shown in FIG. 5A, a predetermined peak current Ip is applied to a large current value to form and transfer droplets, and as shown in FIG. In addition, a peak voltage Vp proportional to the arc length is applied. During a base period Tb determined by arc length control, which will be described later, as shown in FIG. 4A, a base current Ib that is set in advance to a small current value is applied to prevent formation of droplets, and FIG. As shown, a base voltage Vp proportional to the arc length is applied. The above-described peak period Tp and base period Tb are repeated as one pulse period Tf, and welding is performed.

  In consumable electrode arc welding including mag pulse welding, maintaining the arc length during welding at an appropriate value is important for obtaining good welding quality. This arc length control is performed as follows. The average value Vav of the welding voltage shown in FIG. 5B is substantially proportional to the arc length. For this purpose, the welding voltage average value Vav is detected, and the above-described base period is set such that the welding voltage average value Vav is equal to a predetermined welding voltage setting value Vr (not shown) so as to correspond to the appropriate arc length. Tb is changed by feedback control. Since the peak period Tp is a predetermined value, controlling the base period Tb is equivalent to controlling the pulse period Tf. For this reason, this arc length control is generally called frequency modulation control.

  In the mag pulse welding shown in the figure, when one droplet moves in synchronization with one energization of the peak current Ip (so-called 1 pulse 1 droplet transfer state), the welding state is stabilized and spatter is generated. Is also very low. In order to create this one-pulse / one-droplet transfer state, it is important that the peak period Tp, the peak current Ip, and the base current Ib are set to appropriate values. In addition, it is also beneficial to use the above-described pulse arc welding wire in order to obtain a one-pulse / one-droplet transfer state. This wire for pulse arc welding is a welding wire that has been devised for its composition component and is likely to be in the state of transition to one pulse / one droplet. What is important as welding conditions other than these is the welding voltage set value Vr for setting the feed speed and arc length of the welding wire. When the workpiece is determined, the optimum welding current average value is determined, and the feeding speed is determined accordingly. The welding voltage set value Vr is determined so that the arc length is appropriate for this feed speed. Based on the welding voltage set value Vr, the arc length control described above is performed. When the main welding conditions in the mag pulse welding are arranged, the peak period Tp, the peak current Ip, the base current Ib, the type of the welding wire, the feeding speed, and the welding voltage set value Vr are obtained. Good welding quality can be obtained by setting these welding conditions to appropriate values.

Japanese Patent Laid-Open No. 10-286671 JP 2007-160350 A

  As described above, in the mag pulse welding, it is ideal to use a pulse arc welding wire that is likely to be in a 1 pulse 1 droplet transfer state in order to obtain a stable welding state. However, since the pulse arc welding wire is more expensive than the carbon dioxide arc welding wire (JIS standard Z3312: 1999, YGW11 and YGW12), the carbon dioxide arc welding wire may be used in the mag pulse welding. In this case, it is necessary to change the above-described welding conditions (peak period Tp, peak current Ip, base current Ib, feeding speed, and welding voltage set value Vr) to values suitable for the carbon dioxide arc welding wire. However, in a welding power source for mag pulse welding, the above welding conditions are premised on the use of a pulse arc welding wire, and appropriate values are built in. For this reason, in order to perform mag pulse welding using a carbon dioxide arc welding wire, it is necessary to optimize all the above welding conditions. For this purpose, a long welding test is required, and there is a problem that it takes a long time for production preparation.

  Accordingly, an object of the present invention is to provide a welding condition setting method for mag pulse welding that can easily optimize welding conditions even when a carbon dioxide arc welding wire is used.

In order to solve the above-described problem, the first invention
The welding wire is fed at a predetermined feeding speed, a predetermined peak current is applied during a predetermined peak period, a predetermined base current is applied during a base period, and these energizations are performed for one cycle. In the welding condition setting method of mag pulse welding in which the welding is performed by controlling the base period so that the welding voltage average value becomes equal to a predetermined welding voltage setting value.
A wire type selection switch is provided to select the wire mode for carbon dioxide arc welding.
When the carbon dioxide arc welding wire mode is selected, the peak period is corrected to be longer by a predetermined value.
It is the welding condition setting method of the magnet pulse welding characterized by the above-mentioned.

The second aspect of the invention corrects the welding voltage setting value to be increased by a predetermined value when the carbon dioxide arc welding wire mode is selected.
A welding condition setting method for mag pulse welding according to the first aspect of the invention.

The third invention corrects the feeding speed to be increased by a predetermined value when the carbon dioxide arc welding wire mode is selected.
This is a welding condition setting method of mag pulse welding according to the first or second aspect of the invention.

  According to the present invention, even when welding using a carbon dioxide arc welding wire in mag pulse welding, it is only necessary to turn on the wire type selection switch provided in the welding power source and select the carbon dioxide arc welding wire mode. Welding quality can be obtained. In the carbon dioxide arc welding wire mode, the peak period is corrected to be longer by a predetermined value than when the pulse arc welding wire is used in order to stabilize the droplet transfer. Also, the welding voltage set value is corrected so as to increase by a predetermined value. Also, the feeding speed is corrected so as to increase by a predetermined value.

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

  FIG. 1 is a block diagram of a welding power source for carrying out a welding condition setting method of mag pulse welding according to an embodiment of the present invention. Hereinafter, each block will be described with reference to FIG.

  The power supply main circuit PM receives a commercial power supply (not shown) such as three-phase 200V as input, performs output control by inverter control according to a drive signal Dv described later, and outputs a welding current Iw and a welding voltage Vw. Although not shown, the power supply main circuit PM includes a primary rectifier that rectifies commercial power, a capacitor that smoothes the rectified direct current, an inverter circuit that converts the smoothed direct current into high-frequency alternating current according to the drive signal Dv, A high-frequency transformer that steps down the high-frequency alternating current to a voltage value suitable for arc welding, a secondary rectifier that rectifies the stepped-down high-frequency alternating current, and a reactor that smoothes the rectified direct current. The welding wire 1 is fed through the welding torch 4 by the rotation of the feed roll 5 coupled to the wire feed motor WM, and the arc 3 is generated between the base metal 2 and welding is performed.

  When the wire type selection switch ST is turned on, the carbon dioxide arc welding wire mode is activated and a high-level wire type selection signal St is output. When the wire type selection switch ST is turned off, a low-level wire type selection signal St is output.

  The welding voltage detection circuit VD detects and smoothes the welding voltage Vw, and outputs a welding voltage detection signal Vd. The welding voltage setting circuit VR outputs a predetermined welding voltage setting signal Vr. The voltage setting increase value setting circuit DVR outputs a predetermined voltage setting increase value setting signal ΔVr. The voltage setting addition circuit AV receives the welding voltage setting signal Vr, the voltage setting increase value setting signal ΔVr and the wire type selection signal St, and the wire type selection signal St is at a high level (a carbon dioxide arc welding wire). Mode), the value of the welding voltage setting signal Vr and the value of the voltage setting increase value setting signal ΔVr are added and output as a voltage control setting signal Vcr. When the level is low, the welding voltage setting signal Vr is set to voltage control. Output as signal Vcr. The voltage error amplification circuit EV amplifies an error between the voltage control setting signal Vcr and the welding voltage detection signal Vd, and outputs a voltage error amplification signal Ev.

  The voltage / frequency conversion circuit VF receives the voltage error amplification signal Ev, and outputs a pulse period signal Tf having a frequency corresponding to the value of the voltage error amplification signal Ev. The pulse cycle signal Tf is a signal that becomes a high level for a short time every pulse cycle. The peak period setting circuit TPR outputs a predetermined peak period setting signal Tpr. The peak period increase value setting circuit DTP outputs a predetermined peak period increase value setting signal ΔTp. The peak period adding circuit AT receives the peak period setting signal Tpr, the peak period increase value setting signal ΔTp and the wire type selection signal St, and the wire type selection signal St is at a high level (a carbon dioxide arc welding wire). Mode), the value of the peak period setting signal Tpr and the value of the peak period increase value setting signal ΔTp are added and output as the peak period control setting signal Tpc. When the level is low, the peak period setting signal Tpr is output as the peak period. Output as a control setting signal Tpc. The timer circuit TM receives the peak period control setting signal Tpc and the pulse period signal Tf and receives the peak period control setting signal Tpc. The timer circuit TM becomes a high level only for a period determined by the peak period control setting signal Tpc from the time when the pulse period signal Tf becomes the high level The signal Tm is output. Accordingly, when the timer signal Tm is at a high level, the peak period is set, and when the timer signal Tm is at a low level, a base period is set.

  The peak current setting circuit IPR outputs a predetermined peak current setting signal Ipr. The base current setting circuit IBR outputs a predetermined base current setting signal Ibr. The switching circuit SW receives the timer signal Tm, the peak current setting signal Ipr, and the base current setting signal Ibr. When the timer signal Tm is at a high level, the switching circuit SW uses the peak current setting signal Ipr as the current control setting signal Icr. When the low level, the base current setting signal Ibr is output as the current control setting signal Icr. The welding current detection circuit ID detects the welding current Iw and outputs a welding current detection signal Id. The current error amplification circuit EI amplifies an error between the current control setting signal Icr and the welding current detection signal Id, and outputs a current error amplification signal Ei. The drive circuit DV receives the current error amplification signal Ei as input, performs pulse width modulation control, and outputs a drive signal Dv for driving the inverter circuit.

  The welding current average value setting circuit IR outputs a predetermined welding current average value setting signal Ir. The feed speed setting circuit FR receives this welding current average value setting signal Ir and outputs a feed speed setting signal Fr corresponding to this value. The feed rate increase value setting circuit DFR outputs a preset feed rate increase value setting signal ΔFr. The feeding speed setting addition circuit AF receives the feeding speed setting signal Fr, the feeding speed increase value setting signal ΔFr and the wire type selection signal St, and the wire type selection signal St is at a high level (carbonic acid). In the case of gas arc welding wire mode), the value of the feed speed setting signal Fr and the feed speed increase value setting signal ΔFr are added and output as a feed speed control setting signal Fcr. The feed speed setting signal Fr is output as the feed speed control setting signal Fcr. The feed control circuit FC inputs the feed speed control setting signal Fcr and outputs a feed control signal Fc for feeding the welding wire 1 at a feed speed determined by this value to the wire feed motor WM. .

  In the above, when a pulse arc welding wire is used as the welding wire, the wire type selection switch ST is turned off and the wire type selection signal St is set to the Low level. At this time, the welding conditions are set as follows. The peak period Tp is set by the peak period setting circuit TPR, the peak current Ip is set by the peak current setting circuit IPR, the base current Ib is set by the base current setting circuit IBR, and the welding voltage average value Vav is set. Is set by the welding voltage setting circuit VR, and the feeding speed is set by the feeding speed setting circuit FR. These setting methods are the same as those in the prior art. That is, appropriate values for each welding condition parameter are preset.

  On the other hand, when a carbon dioxide arc welding wire is used as the welding wire, the wire type selection switch ST is turned on and the wire type selection signal St is set to High level (carbon dioxide arc welding wire mode). At this time, the welding conditions are set as follows. First, since the set values of the peak current Ip and the base current Ib may be the same as those when the pulse arc welding wire is used, they are set by the peak current setting circuit IPR and the base current setting circuit IBR. However, the peak period Tp, the welding voltage average value Vav, and the feeding speed must be corrected from the values when the pulse arc welding wire is used. For this reason, in the carbon dioxide arc welding wire mode, the peak period Tp is corrected to be longer by a predetermined value by adding the peak period increase value setting signal ΔTp to the peak period setting signal Tpr as described above. Is done. Similarly, the welding voltage average value Vav is set to increase by a predetermined value by adding the voltage setting increase value setting signal ΔVr to the welding voltage setting signal Vr as described above. Further, as described above, the feeding speed is corrected so as to increase by a predetermined value by adding the feeding speed increase value setting signal ΔFr to the feeding speed setting signal Fr. The reason for correcting the peak period Tp is to stabilize the droplet transfer state when the carbon dioxide arc welding wire is used. Since the carbon dioxide arc welding wire does not smoothly transfer the droplet compared to the pulse arc welding wire, the heat input to the droplet is increased by increasing the peak period Tp to promote the transfer. . As a numerical example, the peak period of about 1 to 2 ms is increased by about 0.5 ms. The reason for correcting the welding voltage average value Vav is that the welding voltage average value Vav needs to be made larger than when the pulse arc welding wire is used in order to set the appropriate arc length. If a numerical example is given, it will be enlarged about 1-2V. The reason for correcting the feeding speed is that it is necessary to make the feeding speed faster than when the pulse arc welding wire is used in order to obtain a welding current average value suitable for the workpiece. As a numerical example, it is necessary to increase the speed by about 10%. The increase value of the peak period Tp and the welding voltage average value Vav may be changed in conjunction with the feeding speed. In a welding apparatus using a welding robot, the wire type selection signal St may be set by a teach pendant.

  According to the above-described embodiment, even in the case of welding using a carbon dioxide arc welding wire in magnet pulse welding, the wire type selection switch provided in the welding power source is turned on to select the carbon dioxide arc welding wire mode. Good welding quality can be obtained. In the carbon dioxide arc welding wire mode, the peak period is corrected to be longer by a predetermined value than when the pulse arc welding wire is used in order to stabilize the droplet transfer. Also, the welding voltage is corrected so as to increase by a predetermined value in order to make the arc length appropriate. Further, the feeding speed is also corrected so as to increase by a predetermined value in order to make the welding current average value appropriate.

It is a block diagram of the welding power source for implementing the welding condition setting method of the mag pulse welding which concerns on embodiment of this invention. It is a current and voltage waveform diagram of mag pulse welding in the prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Welding wire 2 Base material 3 Arc 4 Welding torch 5 Feed roll AT Peak period addition circuit AV Voltage setting addition circuit DFR Feed rate increase value setting circuit DTP Peak period increase value setting circuit DV Drive circuit Dv Drive signal DVR Voltage setting increase Value setting circuit EI Current error amplification circuit Ei Current error amplification signal EV Voltage error amplification circuit Ev Voltage error amplification signal FC Feed control circuit Fc Feed control signal Fcr Feed speed control setting signal FR Feed speed setting circuit Fr Feed speed Setting signal Ib Base current IBR Base current setting circuit Ibr Base current setting signal Icr Current control setting signal ID Welding current detection circuit Id Welding current detection signal Ip Peak current IPR Peak current setting circuit Ipr Peak current setting signal IR Welding current average value setting circuit Ir welding current average value setting signal Iw welding current PM power main circuit ST wire Type selection switch St Wire type selection signal SW Switching circuit Tb Base period Tf Pulse period (signal)
TM Timer circuit Tm Timer signal Tp Peak period Tpc Peak period control setting signal TPR Peak period setting circuit Tpr Peak period setting signal Vav Welding voltage average value Vcr Voltage control setting signal VD Welding voltage detection circuit Vd Welding voltage detection signal VF Voltage / frequency conversion Circuit Vp Peak voltage Vp Base voltage VR Welding voltage setting circuit Vr Welding voltage setting (value / signal)
Vw Welding voltage WM Wire feed motor ΔFr Feed speed increase value setting signal ΔTp Peak period increase value setting signal ΔVr Voltage setting increase value setting signal

Claims (3)

The welding wire is fed at a predetermined feeding speed, a predetermined peak current is applied during a predetermined peak period, a predetermined base current is applied during a base period, and these energizations are performed for one cycle. In the welding condition setting method of mag pulse welding in which the welding is performed by controlling the base period so that the welding voltage average value becomes equal to a predetermined welding voltage setting value.
A wire type selection switch is provided to select the wire mode for carbon dioxide arc welding.
When the carbon dioxide arc welding wire mode is selected, the peak period is corrected to be longer by a predetermined value.
A method for setting welding conditions for mag pulse welding. When the carbon dioxide arc welding wire mode is selected, the welding voltage setting value is corrected to be increased by a predetermined value.
The welding condition setting method for mag pulse welding according to claim 1. When the carbon dioxide arc welding wire mode is selected, the feeding speed is corrected to be increased by a predetermined value,
The welding condition setting method for mag pulse welding according to claim 1 or 2.

Images