JPH026064A - Engine-driven welding machine with ac power source - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [J Previous Study] A welding current supply circuit that supplies welding current to the welding output section, and an auxiliary current supply circuit that rectifies an alternating voltage and supplies auxiliary current to the welding output section. In addition to providing
Regarding an engine-driven welding device with an AC power supply having an AC power supply circuit for supplying power to an AC load, a current transformer having a magnetic core is interposed between the auxiliary current supply circuit and the AC power supply circuit, and the engine is powered on when there is no load. Configured to remain idle.

[Industrial application field]

The present invention relates to an engine-driven welding device with an AC power source in which the engine is controlled to be in an idle state when either the AC load or the welding load is in a no-load state.

In the engine-driven welding device as described above.

It is desirable to control the engine to idle during no-load conditions to reduce noise and conserve fuel.

[Conventional technology]

l8 A type of alternating current that can also supply alternating current to general alternating current loads in an engine-driven generator that supplies direct current,
Engine-driven welding equipment with a current source is known.

For example, Utility Model Application Publication No. 13736 of 1988 has been published regarding a configuration for controlling the engine to an idle state when there is no welding load or AC load in this type of engine-driven welding apparatus.

FIG. 4 shows a conventional configuration disclosed in the official gazette. The code 1 in the figure is the main winding of the engine drive generator, and 2 is the field:? ! 5 wires, 3 is a rectifier circuit that supplies welding current, 4 is a welding output section, 5 is a general AC load output section 56
7 is a current transformer, which is composed of an induction detection line connected to both the welding current output line and the AC power supply current output line, 7 is a current detector, and 8 is a solenoid that controls the engine. It represents switching between an idle state and a high-speed operation state.

In FIG. 4, when welding is performed, direct current is transmitted from the rectifier circuit 3 through the welding current output line 9 to the welding output section 4.
supplied to Further, an alternating current is supplied to the general alternating current load output section 5 through an output line 10 for the alternating current power supply current.

Since the above-mentioned welding current is rectified by the rectifier circuit 3, the relevant? The alternating current includes a ripple component, and when welding work is started, an alternating current is supplied to the current detector 7 via the current transformer 6. Further, when power is supplied to a general AC load, an alternating current is similarly supplied to the current detector 7 via the current transformer 6. For these reasons, when no alternating current is supplied to the current detector 7 (including when the current is below the dark value), it is assumed that there is no load, and the solenoid 8 switches the fuel supply device to η'411.
1L, let the engine idle.

In the configuration shown in FIG. 4, regarding the current transformer 6, the induction detection wire 11 is wound around several turns around both the welding current output line 9 and the AC power supply current output line lO. It adopts a hanging shape, and is characterized by its simple structure.

[Problem to be solved by the invention]

When using the above-mentioned conventional method, the following points need to be fully considered. That is.

(1) As the welding output increases, the welding current output line 9
becomes thicker. For example, in the case of 140 (A) class, 14
In the case of 280 (A) class, a wire with a diameter of 22 [mm2] or more is required.For this reason, if an insulating layer is provided on the above wire, the diameter will be considerably large. Become something.

As a result, the shape of the current transformer 6 itself tends to become considerably larger.

(2) Furthermore, since the induction detection line 11 is wound around the output lines 9 and 10, the detection sensitivity is inferior to that of a normal current transformer having a magnetic core.

(3) Furthermore, generally, the lead wire from the induction detection wire 11 shown in FIG. 4 to the current detector 7 is kept short.

In addition, since the layout dimensions from the current detector 7 to the solenoid 8 are kept small, the output lines 9 and 10 are
It becomes necessary to route it to the vicinity of the position where the solenoid 8 is present. For this reason, as mentioned above, the output wire 9 with a large wire diameter is
The routing route tends to be long.

On the other hand, the inventors of the present invention first rectified the alternating voltage generated by a generator in an engine-driven welding device using a rectifier circuit including a water leak, and supplied a welding current using the thyristor. We propose a configuration to control this.

In the case of this configuration, if an attempt is made to control the welding current by phase control using the thyristor, when the welding current is throttled down, a period of zero current is likely to occur due to the phase control. It is necessary to prevent the arc from disappearing undesirably.

It is proposed to supply an auxiliary current together with the above welding current.

An object of the present invention is to provide a configuration that controls the engine to be in an idle state when there is no load, while taking the above-mentioned conventional configuration into consideration.

[Means to solve the problem]

FIG. 1 shows a basic configuration diagram of the present invention. The code 1 in the figure is the main winding of the generator driven by the engine I2, l-1
is the AC power supply winding, and 2 is the field winding.

3-1 is a first rectifier circuit including a thyristor, 3-2 is a second rectifier circuit, 4 is a welding output section, 5-I is each single-phase AC load output section, 5-2 is a three-phase AC load Output section, 6 is a current transformer, 7 is a current detector.

8 represents a solenoid, 12 an engine, 13 a welding current supply circuit, 14 an auxiliary current supply circuit, and 15 an AC power supply circuit.

The first rectifier circuit 3-1 includes a thyristor, and is configured so that the magnitude of the welding current can be controlled by controlling the gate of the thyristor, as shown by the waveform a in the figure.

The second rectifier circuit 3-2 is a rectifier circuit that does not include a Nyristor, and supplies an auxiliary current as shown in the waveform shown in the figure.

In the case shown in FIG. 2, the AC power supply winding 1-1 is provided as a winding separate from the main winding 1. The current transformer 6 is
It has an annular magnetic core 16, and a secondary winding 17 is wound on the magnetic core IG.

A line forming the auxiliary current supply circuit 14 and a line forming the AC power supply circuit 15 pass through the center of the magnetic core 16 .

C action] When welding is started in the welding output section 4, the DC current rectified by the first rectifier circuit 3-1 is supplied as a welding current. At this time, if the welding current is narrowed down by controlling one thyristor, the welding current may have a period of zero current, as shown in the shaded waveform in waveform a in Figure 1. In this case, the welding output section 4, the arc is easily extinguished.For this reason, in the configuration shown in 1, an auxiliary current as shown in the waveform shown in the drawing is supplied to the welding output section 4 from the second rectifier circuit 3-2 which does not have a thyristor, This prevents the arc from disappearing.

When a load is connected to the three-phase AC load output section 5-2 or when a load is connected to the single-phase AC load output section 5-1, power is supplied to the load from the AC power supply winding 1-1. be exposed.

In the case shown in FIG. 1, when welding work is started in the welding output section 4 or an alternating current load is connected, an alternating magnetic field is generated in the magnetic core 16 of the current transformer 6, and the secondary winding 17 An alternating current is supplied to the current detector 7 via. When the no-load state occurs, the alternating current detected by the current detector 7 becomes less than the dark value, and the solenoid 8 is RJ controlled to put the engine I2 in the idle state.

In addition, the control by this solenoid 8 is 1 example.

In gasoline engines, this is done by forcibly reducing the opening degree of the throttle, and in diesel engines, this is done by forcibly moving the control rank to the side of reduced fuel consumption. Of course, when the load condition is reached, the engine 12 is switched to a high speed operation condition.

In the case shown in FIG. 1, an auxiliary current of about 2 (A) to 15 (A) is generally sufficient, and the auxiliary current supply circuit 14
A line with a small diameter is sufficient for forming the line. For this reason, even if the line is routed to the location where the current transformer 6 is installed, it does not pose much of a problem. Further, the annular magnetic core 16 can be made small. Furthermore, since the 6n air core 16 is used, the detection sensitivity is increased.

〔Example〕

FIG. 2 shows the configuration of an embodiment of the present invention, which includes two welding output sections (distinguished as A system and B system).
An engine-driven welding device is shown having a. The symbols in the figure correspond to those in FIG. 1, and those with A represent the A system, and those with B represent the B system. Also 26.
27 is a switch that switches in conjunction with each other; 9, for example,
It is composed of a two-pole long-stage switch, and allows the A system and B system to be operated in parallel if necessary.

In the case shown in FIG. 2, (i) the line of the A-system auxiliary current supply circuit 14A, (i
i) Line of auxiliary current supply circuit 14B of B system, (ii
i) and the lines of the AC power supply circuit 15 are coupled.

As a result, (i) when welding current is supplied in A system.

(ii) When supplying welding current in system B, (iii)
When the single-phase AC load output section is on, or (iv) when the three-phase AC load output section is on, the engine is placed in an idle state.

FIG. 3 shows another embodiment of the invention. The symbols in the figure correspond to those in FIG. The case shown in FIG. 3 differs from the case shown in FIG. 2 in that it has independent windings for supplying auxiliary current, that is, auxiliary current supply windings 18A and 18B.

In terms of operation, the embodiment shown in FIG. 3 may be considered to be substantially identical to that shown in FIG.

In addition, in FIGS. 1 to 3, the rectified current in the auxiliary current supply circuit 14 (14A, 14B) is shown to be coupled to the magnetic core 16 of the current transformer 6, but if necessary, the rectified current may be The previous alternating current may be coupled to the magnetic core 16.

〔Effect of the invention〕

As explained above, according to the present invention, the start of welding is detected based on the auxiliary current, so it is sufficient that the wire intersecting the magnetic core of the current transformer has a small wire diameter, and the wire can be routed relatively easily. Furthermore, since a current transformer having a magnetic core is used, detection sensitivity is increased.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the basic configuration of the present invention, FIG. 2 is a configuration diagram of one embodiment of the present invention, FIG. 3 is a diagram showing another embodiment of the present invention, and FIG. 4 is a conventional configuration. In the figure, l is the main winding of the engine drive generator, 11 is the AC power supply winding, 2 is the field winding, 3-1 is the first rectifier circuit, 3
-2 is a second rectifier circuit, 4 is a welding output section, 5-1 is a single-phase AC load output section, 5-2 is a three-phase AC load output section, 6 is a current transformer, 7 is a current detector, 8 12 is a solenoid, 12 is an engine, 13 is a welding current supply circuit, and 14 is an auxiliary current supply circuit. 15 represents an AC power supply circuit, and 16 represents a magnetic core. Patent Applicant Sawafuji Electric Co., Ltd. (1 other person) Representative Patent Attorney Hiroshi Mori 1) (3 others) Example [I] Part 2 Figure 1/ Implementation I91 [11]

Claims (1)

[Claims] A welding device comprises an engine and a generator driven by the engine, and the alternating voltage generated by the generator is rectified by a first rectifier circuit including a thyristor and then sent to a welding output section. In an engine-driven welding device with an AC power source, which is equipped with a welding current supply circuit that supplies welding current and an AC power supply circuit that supplies AC power to a load from the AC power supply supplied by the generator, an engine-driven welding device that does not include a thyristor an auxiliary current supply circuit that rectifies the alternating voltage using a second rectifier circuit and supplies an auxiliary current to the welding output section; a line that constitutes the auxiliary current supply circuit; and a line that constitutes the AC power supply circuit. and a current transformer having a magnetic core that is electromagnetically engaged with each other, and a current detector that detects the output of the current transformer, and based on the detection result by the current detector,
An engine-driven welding device with an AC power source, characterized in that the engine is controlled to switch between an idle state and a high-speed operating state.