JP2884548B2 - Power supply and multi-arc welding equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device using a single-turn transformer and a multi-arc welding device.

[Conventional technology]

A conventional multi-arc welding apparatus uses a three-phase transformer 20 having primary and secondary coils 21 and 22 as shown in FIG. To generate a multi-arc between the welding electrode and the workpiece and between the welding electrodes to perform multi-arc welding.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus for performing multi-arc welding with a configuration completely different from the conventional apparatus and a power supply apparatus for the apparatus.

[Means for solving the problem]

The power supply device according to the present invention is a device that generates a voltage necessary to generate a multi-arc, and controls a phase of a three-phase sine wave alternating current to output a voltage of about 100 °
A phase control circuit that outputs only a range of about 180 ° or about 120 ° to about 180 °, and a three-phase coil wound around an iron core, and one end of the three-phase coil receives each output of the phase control circuit. On the other hand, the other ends of the three-phase coils are connected to each other at a reference potential, and are provided with a transformer for extracting a power supply output from each intermediate point of the three-phase coils.

In such a configuration, when the three-phase sine wave alternating current is input to the three-phase coil of the transformer through the phase control circuit, a magnetic flux having a triple frequency drooping characteristic is generated in the iron core of the transformer. . A voltage corresponding to the change in the magnetic flux is generated at each intermediate point of the three-phase coil, and is taken out as a power supply output.

More preferably, the phase control circuit includes only the range of about 120 ° to about 180 ° of the positive and negative half waves of the first phase, and the range of about 0 ° to about 180 ° of the positive and negative half waves of the second phase. Only about 60 ° to about 180 ° out of the positive and negative half-waves of the third phase, while the transformer is configured such that the third phase of the three-phase coil is wound in reverse phase. It is desirable to do so.

In such a configuration, since the magnetic flux generated in the iron core of the transformer is increased as compared to the above, the voltage of the power supply output also increases accordingly.

The multi-arc welding apparatus according to the present invention is basically the same as above, and the phase of the three-phase sine wave alternating current is controlled to about 100 ° to about 180 ° or about 120 ° or more for each of the positive and negative half waves of each phase. About 180 °
A three-phase coil wound around an iron core, and one end of the three-phase coil receives each output of the phase control circuit while the other end of the three-phase coil Has a transformer connected to a common ground terminal, and the material to be welded is connected to the common ground terminal, while three welding rods are respectively connected to the intermediate points of the three-phase coils of the transformer. Further, an arc is generated between each welding rod and the material to be welded and between the welding rods to perform multi-arc welding.

More preferably, the phase control circuit includes only the range of about 120 ° to about 180 ° of the positive and negative half waves of the first phase, and the range of about 0 ° to about 180 ° of the positive and negative half waves of the second phase. And only about 60 ° to about 80 ° of the positive and negative half-waves of the third phase are output, while the transformer is wound in the reverse phase of the third phase of the three-phase coil. It is desirable to do so.

〔Example〕

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

FIG. 1 shows a power supply device and a multi-arc welding device according to an embodiment of the present invention. In the drawing, 1, 2 and 3 denote three-phase AC power terminals, and 4 denotes a phase firing angle of three-phase AC to be supplied. A phase control circuit for controlling, 50 is a single-winding transformer in which three primary coils 5, 6, 7 are wound around its primary iron core, and a secondary output is taken out from the midpoint of each, and 100 is phase control. This is a power supply device including the circuit 4 and the autotransformer 50. Also,
8, 9, 10 are three welding electrodes connected to the respective secondary outputs, 11 is a workpiece to be connected to the neutral terminals of the three primary coils 5, 6, and 7, and 13 is a welding material. An arc between the electrodes 8, 9, 10 and the workpiece 11 and an arc 13 'between the welding electrodes 8, 9, 10 are shown. Here, the arc 13 'does not normally occur at a firing angle of 120 ° or more. Reference numeral 300 denotes a welding portion for performing multi-arc welding.

FIG. 1 (b) shows the details of the phase control circuit 4, in which 20a, 20b and 20c are thyristors, and 21 is a zero cross point detector for detecting a zero cross point of a sine wave of each phase of three-phase AC. , 22a, 22
b and 22c are phase adjusters which receive the output of the zero cross point detector and adjust the firing angles of the thyristors 20a, 20b and 20c of each phase.

FIG. 1 (c) shows another example of the welded portion of the above embodiment,
8,9,10,8 ', 9', 10 'are materials to be welded facing each other and should be welded to each other, 13 is between 8,9,10,8', 9 ', 10' The arc 13 'is an arc between the upper and lower phases of the workpieces. Numeral 14 denotes an inert gas or a flux provided so as to surround a space where an arc is generated, and this is for creating a state where it is not oxidized.

FIG. 2 (a) is a diagram for explaining the ignition control operation by the phase control circuit 4, and FIG.
The following output is shown.

FIGS. 3 (a) and 3 (b) are diagrams for explaining the operation principle of a normal single-wound transformer. Reference numeral 30 denotes a primary coil, from which a secondary output is taken from an intermediate point. Also
Reference numerals 31 and 32 denote the resistance of the upper half and the lower half of the primary coil 30.

 Next, the operation will be described.

In the present embodiment, the energization of the three-phase coils 5, 6, and 7 of the transformer 50 from the three-phase AC power supplies 1, 2, and 3 is controlled by the phase controller 4, and as shown in FIG. The coils 5, 6, and 7 have a phase angle of 100 ° to 18 of the AC sine waveform X, Y, Z of each phase.
The energization is performed only within the range of 0 ° (c and f for X, b and e for Y, and a and d for Z), and other times the coils are open.

When energization is sequentially repeated to the three-phase coils 5, 6, 7 in this manner, a magnetic flux having a triple frequency drooping characteristic as shown in FIG. 2 (b) is induced in the iron core, Since the secondary output of the single-turn transformer 50 is taken out from the intermediate point between the primary coils 5, 6, and 7, each of the welding electrodes 8, 9, and 10 has the drooping characteristics shown in FIG. Each of the sawtooth waves has a flow, and a triple frequency arc current flows as a whole. In the case of a large capacity, as shown in FIG. 4 (c), the center member 14, which is the material to be welded, is grounded, and the secondary output of the transformer 50 is connected between the central member 14 and the three materials 8, 9, 10 (see FIG. Fig. 4 (a)
Are added, the three arcs 13 are generated at the same time, and multi-arc welding is performed. Here, also in FIG. 4 (c), the space where the arc is generated is surrounded by the inert gas or the flux.
At this time, the following effects can be obtained.

In this embodiment, a single winding transformer is used. As shown in FIGS. 3 (a) and 3 (b), when a current of 10A flows through the primary winding, a secondary output taken from the middle point is applied to the primary winding. Is designed to provide a current of 20 A, so that the no-load voltage can be reduced to about 1/2 of the conventional value. Further, since a single-winding transformer having no secondary winding is used, a significant reduction in size and weight can be achieved.

As shown in the second embodiment of FIG. 4, the fourth welding electrode 12 connected to the neutral terminal is connected to three welding rods 8,
By arranging in the middle of 9,10 (FIG. 4 (a) is arranged outside for simplicity of illustration), 8,9,10 and 11
A total of 9 arcs can be generated between 8, 9, 10 and 8, 9, 10, and 12 to perform welding, and very powerful multi-arc welding can be performed.

Since the power supply used in the present invention has a drooping characteristic as described above, a leakage magnetic flux type device generally used to obtain the drooping characteristic or a saturable type as shown in FIG. There is no need to use the reactor L or the like, and there is no accompanying loss or reduction in power factor.

In addition, the frequency obtained is three times as large as the total of the three welding electrodes.
Only 3 is required, making it very small and lightweight. Further, since the structure of the transformer is simple and small and lightweight, the manufacturing cost can be greatly reduced.

In contrast to the conventional multi-arc welding apparatus using the three-phase transformer 20 shown in FIG. 5, the present invention uses a single-winding transformer, so the weight is 30% and the price is only 1/4, which is safe and easy to handle. It is simple, does not require technical skills, and is easy to automate.

By appropriately adjusting the firing angle of the one-phase AC sinusoidal waveform back and forth around 120 degrees, the arc intensity can be greatly adjusted.

In other words, by performing automatic control by a computer, finer adjustment than the conventional commercial frequency becomes possible,
Great welding stability can be obtained.

Also, since the arc is small and lightweight and the arc is stable, it can be mounted on a robot to perform arc welding of a large thick plate. That is, with the same weight,
Double welding ability can be demonstrated.

By directly attaching to the robot, a straight-type welding rod can be used without wire swinging, and welding or overlaying can be performed with a super-steel or a large-diameter welding rod.

Since the welding capacity is greatly improved, a thick welding rod or a thick flux-cored wire can be used even with the same KVA.

As shown in the third embodiment of FIG.
If a secondary winding 18 is further provided on 50 and a voltage is applied to the welding wire 24 using this to resistance-heat the wire 24, the secondary output is a triple-frequency sawtooth wave, so that the heating effect is obtained. Since it is large and does not cause uneven heating, it is possible to perform good quality and stable MIG welding with little spatter, and it is possible to obtain overlays 27 and 23 by welding or thermal spraying as shown in the multi-arc welding a section.

If the power supply of the present invention is used for all welding including submerged welding, electroslag welding, and thermal spraying, welding and thermal spraying with few defective portions such as entanglement and pinholes can be efficiently performed by various actions of high frequency sawtooth wave electromagnetic force. You can get it.

FIG. 8 (a) shows a fourth embodiment of the present invention, which is one of the three phases in the first embodiment, in this case the third one.
The phases are reversed, and for each of the positive and negative half-waves of the 1,2,3 phases, the respective firing ranges are 120 ° -180 °, 0 ° -180
And the resulting waveform is a 60-cycle sawtooth wave having a large wave height as shown in FIG. 8 (b), and the three-phase equilibrium is slightly distorted, but the arc welding energy is Be more powerful. However, when securing a three-phase equilibrium and performing larger welding, each phase to be reversed should be 1
It is preferable to use nine electrodes of three types, namely, two phases, two phases, and three phases.

In the above, the case where welding is performed by forming an arc between the base material and the welding rod has been described. For example, as shown in FIG. 9 (a), three round bars are collectively grounded, and 8, 9, and 10 may be applied to perform welding at once. As shown in FIGS. 9 (b), (c) and (d),
It is also possible to weld a deformed object by making use of the characteristics of each phase shown in FIG.

[Effects of the Invention] As described above, in the case of the power supply device according to claim 1 of the present invention,
When the three-phase sine wave alternating current is input to the three-phase coil of the transformer through the phase control circuit, a magnetic flux having a triple frequency drooping characteristic is generated in the iron core of the transformer, and each intermediate portion of the three-phase coil is generated. At the point, a voltage corresponding to the change of the magnetic flux is generated and taken out as a power supply output. That is, the configuration is such that the drooping characteristic required to generate a multi-arc is obtained only by a transformer and a phase control circuit in which a three-phase coil is wound around an iron core without using a three-phase transformer. In addition, the size and weight of the device can be significantly reduced and the cost can be reduced.

In the case of the power supply device according to claim 2 of the present invention, since the magnetic flux generated in the iron core of the transformer is increased as compared with the above, the voltage of the power supply output is also increased accordingly,
The output of the device can be increased.

In the case of the multi-arc welding apparatus according to claim 3 of the present invention, since the multi-arc welding apparatus is configured to perform multi-arc welding based on the power supply output generated by the power supply apparatus of claim 1,
Advantages similar to those of the first aspect are obtained.

In the case of the multi-arc welding apparatus according to claim 4 of the present invention, the multi-arc welding is performed based on the power supply output generated by the power supply apparatus of claim 2, so that the same merits as in claim 2 are obtained. can get.

[Brief description of the drawings]

FIG. 1 is a block diagram of a multi-arc welding apparatus according to one embodiment of the present invention, FIG. 2 is a diagram showing a three-phase input waveform input to the autotransformer 50 and an output waveform having a drooping characteristic, FIG. FIG. 4 shows the principle of operation of a single-wound transformer, FIG. 4 shows a multi-arc welding apparatus according to a second embodiment of the present invention, FIG. 5 shows a conventional three-phase transformer, and FIG. Figure showing an arc welding machine using a saturable reactor of
FIG. 7 is a diagram showing an apparatus for simultaneously performing MIG welding and thermal spraying or multi-arc "a" to a resistance heating apparatus according to a third embodiment of the present invention, and FIG. 8 is a fourth embodiment of the present invention. FIG. 9 is a view showing an example, and FIG. 9 is a view showing an example of welding utilizing these features. In the figure, 1, 2, and 3 are three-phase AC power supply terminals, 100 is a power supply device, 4 is a phase control circuit, 50 is an autotransformer, 5, 6, and 7 are 1
Next coil, 8, 9, and 10 are welding rods, 11 is a base material to be welded, 12 is a welding electrode with neutral potential, 30 is a coil of a single-turn transformer, 3
1 and 32 are resistors, and 20 is a three-phase transformer. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (4)

(57) [Claims] In a power supply device for generating a voltage required to generate a multi-arc, a phase of a three-phase sine wave alternating current is controlled so that about 100 ° to about 180 ° or A phase control circuit that outputs only a range of about 120 ° to about 180 °, a three-phase coil wound around an iron core, and one end of the three-phase coil receives each output of the phase control circuit, A power supply device, comprising: a transformer for connecting the other ends of the three-phase coils to each other to have a reference potential and extracting a power output from each intermediate point of the three-phase coils. 2. The phase control circuit according to claim 1, wherein only the range of about 120 ° to about 180 ° of the positive and negative half waves of the first phase and about 0 ° to about 180 ° of the positive and negative half waves of the second phase. , And only about 60 ° to about 180 ° of the positive and negative half-waves of the third phase are output, while the transformer is configured such that the third phase of the three-phase coil has the opposite phase. The power supply device according to claim 1, wherein the power supply device is wound. 3. A phase control of a three-phase sine wave alternating current, wherein about 100 ° to about 180 ° or about 120 ° to about 180 ° of each of the positive and negative half waves of each phase.
A three-phase coil wound around an iron core, and one end of the three-phase coil receives each output of the phase control circuit while the other end of the three-phase coil Has a transformer connected to a common ground terminal, and the material to be welded is connected to the common ground terminal, while three welding rods are respectively connected to the intermediate points of the three-phase coils of the transformer. A multi-arc welding apparatus characterized in that an arc is generated between each welding rod and a material to be welded and between each welding rod to perform multi-arc welding. 4. The phase control circuit according to claim 1, wherein only the range of about 120 ° to about 180 ° of the positive and negative half waves of the first phase and about 0 ° to about 180 ° of the positive and negative half waves of the second phase. , And only about 60 ° to about 180 ° of the positive and negative half-waves of the third phase are output, while the transformer is configured such that the third phase of the three-phase coil has the opposite phase. The multi-arc welding device according to claim 3, wherein the multi-arc welding device is wound.