JPH03285768A - Tig welding power source controller - Google Patents

Abstract

PURPOSE:To make an output current waveform into a desired low-frequency pulse on which a medium-frequency pulse is superimposed by combining an external controller with first and second remote control regulators on a TIG welding power source wherein a waveform controller for the medium-frequency pulse is incorporated. CONSTITUTION:The first and second remote control regulators 11 and 12 capable of setting a pulse current and a base current separately respectively are combined with the external controller 5 which can carry out each time setting of a pulse period and a base period of the low-frequency pulse and operates repeatedly so as to input pulse current and base current set signals from the first remote control regulator 11 during the pulse period and further, pulse current and base current set signals from the second remote control regulator 12 during the base period, respectively to the waveform controller 29 incorporated in the TIG welding power source 1 on the TIG welding power source 1 wherein the waveform controller 29 for the medium-frequency pulse is incorporated and the output current waveform is made into the low-frequency pulse on which the medium-frequency pulse is superimposed by the waveform controller 29.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention makes the output current waveform of a TIG welding power source a low-frequency pulse on which a medium-frequency pulse is superimposed (hereinafter referred to as a medium-frequency pulse superimposed low-frequency pulse). This invention relates to a control device for

[Prior Art] Among the current waveforms used in TIG welding, the relationship among low frequency pulses, medium frequency pulses, and medium frequency pulse superimposed low frequency pulses is shown in FIG.

The main purpose of low frequency pulses (0.1 to several Hz) is to control the heat input to the base metal, which melts the base metal during the pulse period, promotes solidification during the base period, and melts the molten metal. This method is suitable for all-position welding of piping and welding of joints with different plate thicknesses.

Medium frequency pulses (several tens to hundreds) (z) are designed to improve the rigidity and concentration of the arc by increasing the pulse frequency, and are suitable for low current welding and high speed welding where the arc tends to wander.

Medium-frequency pulse superimposed frequency pulse is a combination of a low-frequency pulse and a medium-frequency pulse, and can simultaneously utilize the heat input control effect of the low-frequency pulse and the arc concentration improvement effect of the medium-frequency pulse.

Some conventional TIG welding power sources have a built-in waveform control device that can independently control low-frequency pulses and medium-frequency pulses, but there are still no examples of devices that can control the combination of low-frequency pulses and medium-frequency pulses. do not have.

[Problem to be solved by the invention]

In order to make the output current waveform into a medium-frequency pulse superimposed low-frequency pulse, a special control device is required that can simultaneously control the waveforms of both the low-frequency pulse and the medium-frequency pulse, and such a control device can be used as a welding power source. Having a built-in welding power source will increase the number of welding power sources, which is not economically advisable.

The present invention has been made in consideration of the above points, and is an economical TIG welding method that allows the output current waveform to be a desired medium-frequency pulse superimposed low-frequency pulse by using it in combination with an existing medium-frequency pulse power source. The purpose of this invention is to provide a power supply control device.

[Means to solve the problem]

To achieve the above object, the present invention provides a TIG welding power source with a built-in waveform control device for medium frequency pulses, first and second remote control regulators that can set the pulse current and base current separately, and a low frequency pulse It is possible to set the pulse period and base period of the pulse, and during the pulse period, the pulse current and base current setting signals are sent from the first remote control regulator, and during the pulse period, the pulse current and base current setting signals are sent from the second remote control regulator. an external control device that repeatedly operates to input pulse current and base current setting signals to the waveform control device built into the TIG welding power source, respectively;
The waveform control device built into the TIG welding power source enables
The pulse current setting signal and the base current setting signal input during the pulse period and the base period are alternately switched at the setting frequency of the medium frequency pulse to obtain a waveform control signal, and this waveform control signal causes the output current waveform to be superimposed with the medium frequency pulse. This is a low-frequency pulse.

[Effect]

In the first remote controller, the pulse period T of the low frequency pulse is
, the pulse current IP+ and the base current 1bl are set, and the pulse current Ip□ and the base current Tb2 in the base period T2 of the low frequency pulse are set in the second remote controller. The external control device controls the current setting value (I□, ry) of the first remote control regulator and the current setting value (1-2, Ib2).

The waveform control device built into the TIG welding power source is
In the pulse period T1, the current setting values 1pl and Tbl, and in the base period T2, the current setting values 1p2 and Ib□ are alternately switched at the setting frequency of the medium frequency pulse (pulse period T.) to generate a waveform control signal. to work,
The output current waveform controlled by this waveform control signal becomes a medium frequency superimposed low frequency pulse as shown in FIG.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a connection diagram showing the overall configuration of this embodiment, where 1 is a TIG welding power source used in combination, 5 is an external control device, 11 is a first remote control regulator, 12 is a second remote control regulator; An external control device 5 is connected to the remote control connector 4 of the welding power source 1 via a relay cable 17, and a first remote control adjuster 1 is connected to the first remote control connector 9 of the external control device 5.
1 to the second remote controller connector 10 of the external control device 5 and the second remote controller adjuster 12 to the relay cable 18 .
Use connected by 19. Note that the first remote control adjuster 11 and the second remote control adjuster 12 are the same product, and the standard remote control adjuster of TIG welding electrode a1 can be used for both.

FIG. 2 is a diagram showing the internal configuration of the TIG welding power source 1. This embodiment is an example in which the TIG welding power source 1 is used as an in-harc control type AC/DC dual-purpose power source, where 20 is an input terminal connected to a commercial AC power source, 21 is a primary rectifier that converts AC input to DC, and 22 is a DC power source. High frequency alternating current (e.g. 20k
Hz), 23 is a high frequency transformer,
24 is a secondary rectifier that converts high frequency alternating current into direct current again;
25 is a smoothing reactor, 26 is a current detector, 27 is a switching circuit that can select between DC output and AC output, and 28 is an output terminal connected to a welding load.

29 is a waveform control circuit for medium frequency pulses built into the TIG welding power source 1. When the TIG welding power source 1 is used as a normal medium frequency pulse power source, a remote control regulator ( A pulse current setting signal and a base current setting signal are input from a source (not shown), and these two current setting signals are alternately switched by the waveform control circuit 29 at the setting frequency of the medium frequency pulse to form a waveform control signal. By controlling the output of the inverter 22 with the PWM control circuit 30 so that the current feed bank signal from the current detector 26 matches the current feed bank signal from the current detector 26, the output current waveform is changed to a DC medium frequency pulse or an AC medium frequency as shown in FIG. Pulse. In this way, the waveform control circuit 29 is a switching circuit that repeatedly operates at the set frequency of the medium frequency pulse, and the details of the circuit configuration are omitted from illustration.

FIG. 3 shows a circuit example of the external control device 5. In this example, the external control device 5 is configured with a sequence circuit using a timer and a relay, where T is a timer for pulse time (T1) control, T is a timer for base time (T2) control, IY, 2
Y is a relay, and switches between the first remote control regulator 11 and the second remote control regulator 12 is performed by contacts 2Ya and 2Yb of the relay 2Y.

The pulse current (Ip) setting device 31 in the first remote control regulator 11 and the pulse current (Ip) in the second remote control regulator 12
□) One terminal of each setting device 33 is connected to one terminal of the relay cable 17.
The other two terminals are connected to the other two connection lines 35 and 36 of the relay cable 17 via relay contacts 2Ya and 2Yb. By applying a constant voltage between the connection lines 35 and 37, a voltage corresponding to -Ipl or ■2□ is outputted to the connection line 36 as a pulse current setting signal.

Similarly, the base current (Ib
l) One terminal of each of the setting device 32 and the base current (Ibz) setting device 34 in the second remote control regulator 12 is commonly connected to one connection line 40 of the relay cable 17, and the other two terminals of each are connected in common to one connection line 40 of the relay cable 17. is relay contact 2Y.

, 2Y, to the other two connection lines 38 and 39 of the relay cable 17, and by applying a constant voltage between the connection lines 38 and 40, Ib
A voltage corresponding to l or rbz is output to the connection line 39 as a base current setting signal.

The operating order is as follows when the start switch 8 is turned on.
First, the timer TA is activated, and the relays IY and 2Y do not operate until the set time T1 has elapsed, and the pulse current (Ll) setting device 31 of the first remote control regulator 11 and the base current are connected via the relay contact 2Yb. (Ib,) Setting device 32
is connected to the relay cable 17. When timer TA times up, relay IY is activated by closing timer contact TAH, and timer TB is activated by closing relay contact IY, and relay 2Y is activated.
operates, relay contact 2Yb opens, and timer T is reset. At the same time, the relay contact 2Y is closed and the relay contact 2Yb is opened (thereby, the pulse current of the second remote control regulator 12 instead of the first remote control regulator 11)
An I-z) setting device 33 and a base current Nbz) setting device 34 are connected to the relay cable 17. When the set time T2 elapses and timer TR performs time amplification, timer contact TBb
Since relays IY and 2Y are reset by opening, timer TA becomes activated again, and at the same time relay contact 2Y
a opens and relay contact 2Yb closes, so that the second
The first remote control regulator 11 replaces the remote control regulator 12
pulse current (I, 1) setter 31 and base current (Ib
l) The setting device 32 is connected to the relay cable 17 again, and the timer Tll is reset.

The external control device 5 repeats the above operation and returns the timer to 0. , T6, and T2, the pulse current (rp+) and base current (Ibl) setting signals from the first remote control regulator 11 and the pulse current (Tp) from the second remote control regulator 12 are □) and base current (I
The setting signals b□) are alternately switched and input to the waveform control device 29 built in the TIG welding power source 1.

When the start switch 8 is turned off, all the circuits of the external control device 5 are reset.

When performing welding with a current waveform as a medium-frequency superimposed low-frequency pulse, in FIG. Set the medium frequency pulse frequency (pulse period T.).

Then, use the pulse time setting knob 6 and base time setting knob 7 of the external control device 5 to set the pulse period TI of the low frequency pulse.
, set each time of the base period T2, and use the pulse voltage i setting knob 13 and base current setting knob 14 of the first remote control regulator 41 to set the pulse current 1 pl and base current Ibl of the period T, and set the pulse current 1pl and base current Ibl of the second remote control regulator 12. The pulse current Ip□ and base current 1bl for the T2 period are set using the pulse current setting knob 15 and base current setting knob 16, respectively (I.

>Ip□, Ibl>1bz).

Then, when the start switch 8 of the external control device 5 is set to "man", the above-mentioned repeated operation of the external control device 5 causes the current setting signals of Ipl and Ibl to be set in the T8 period, and ■2□, The current setting signals Tb2 are each input to the waveform control device 29 in the TIG welding power source 1, and the waveform control device 29 outputs the input Ipl, Ibl and ■2 at the setting frequency (pulse period T.) of the medium frequency pulse. Since the waveform control device is configured by alternately switching the current setting signals ゜ and Ib2, the output current waveform is controlled to become a medium frequency superimposed low frequency pulse as shown in FIG.

In FIG. 2, if the output current is taken out by the switching circuit 27 without reversing the polarity, the current waveform becomes a DC medium-frequency superimposed low-frequency pulse. If the polarity is reversed and extracted at a constant AC frequency lower than the frequency of the frequency pulse, the current waveform becomes a low frequency pulse with an AC medium frequency superimposed.

Here, each time of T + , T 2 and Ipl, ■
, 1.1p2, and rbz can be arbitrarily and independently set using their respective setting knobs.If necessary, by setting Ip□-Ib2 or Ipl-1bl, the low-frequency pulse It is also possible to superimpose medium frequency pulses only during the pulse period or only during the base period.

Note that in this embodiment, the control device for the TIG welding power source and the TIG welding power source incorporating the waveform control device for medium frequency pulses are configured separately, but they may be configured as one. Needless to say.

Further, Ipl and 12□ or Ibl and 15□ may be shared by one knob.

Furthermore, if the start switch 8 of the external control device 5 is turned off, the first remote control regulator 11 can be turned off by the TIG welding power source I.
It can perform normal medium frequency pulse control as a remote controller.

Note that although the circuit example in FIG. 3 is an example in which the external control device 5 is constructed using a timer and a relay, reliability and durability can be further improved by using a circuit using semiconductor elements.

〔Effect of the invention〕

According to the present invention, by simply combining an external control device and the first and second remote control regulators with a TIG welding power source that has a built-in waveform control device for medium frequency pulses, the output current waveform can be controlled by heat input control for low frequency pulses. It is possible to create a medium-frequency pulse superimposed low-frequency pulse that has both the action and the arc concentration improvement effect of medium-frequency pulses, and the existing power source for medium-frequency pulses can be used as a welding power source. It is economical and does not require a special power source.

[Brief explanation of the drawing]

Fig. 1 is a connection diagram showing the overall configuration of an embodiment of the present invention, Fig. 2 is a block diagram of the TIG welding power source 1, Fig. 3 is a circuit diagram of the external control device 5, Fig. 4 is a low frequency pulse, FIG. 3 is a current waveform diagram showing the relationship between medium frequency pulses and medium frequency pulse superimposed low frequency pulses. 3 4 1... TIG welding power source, 2... Medium frequency pulse frequency setting knob, 5... External control device, 6... Pulse time setting knob, 7... Base time setting knob, 11.
...First remote control adjuster, 12...Second remote control adjuster, ]3.15...Pulse current setting knob, 14.1
6...Base current setting knob, 29...Waveform control device for medium frequency pulse.

Claims (1)

[Claims] 1. A TIG welding power source with a built-in waveform control device for medium-frequency pulses, first and second remote controllers that can set the pulse current and base current separately, and each of the pulse period and base period of the low-frequency pulse. The time can be set, and the pulse current and base current setting signal from the first remote control regulator are applied during the pulse period, and the pulse current and base current setting signal from the second remote control regulator are applied during the base period. A control device that repeatedly operates so as to be input to a waveform control device built in the TIG welding power source is combined, and a pulse current setting signal input in the pulse period and base period is input by the waveform control device built in the TIG welding power source. This is a TIG welding power source in which the base current setting signal and the base current setting signal are alternately switched at the setting frequency of the medium frequency pulse to obtain a waveform control signal, and the output current waveform is a low frequency pulse superimposed with the medium frequency pulse by this waveform control signal. Control device.