JPH07223074A - Brushless synchronous generator for welding commonly used as ac power source - Google Patents

Abstract

PURPOSE:To supply the stable output to an AC power source and a welding power source by detecting the welding current by a current transformer, and supplying the current to the field winding of an exciter through a rectifier by the signal to generate the exciting output corresponding to the welding output. CONSTITUTION:The voltage is generated in the exciter winding 6 commonly used as an AC power source by the rotation of a rotor 19, and the voltage is generated in the armature winding 9 of the exciter to flow the current. This current is rectified by a rectifier 15, and the current flows in the field winding 8 to generate the magnetic flux. Then, the voltage is generated through the crossing of the armature winding 16 for welding of a stator 17 with the exciter winding 6 commonly used as the AC power source. The welding current during the welding operation is detected by a current transformer 4, and the output is limited by a control circuit 12. The voltage from an open-delta winding 18 is applied to the field winding 7 of the exciter, and the exciting output corresponding to the welding output is generated to the open-delta winding. This constitution supplies the stable welding current to the welding terminal through a rectifier 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC power supply / welding for automatically controlling a welding power supply and an AC power supply such as an electric tool or lighting in a state of being connected to a welding excitation winding and an AC power supply / excitation winding. Brushless synchronous generator.

[0002]

2. Description of the Related Art Conventionally, as an engine-driven generator used for assembling steel frames at a construction site, a welding power source, a generator that uses an AC power source alone as a power source for electric tools, lighting, etc. AC generators and welding generators, which are covered by a single generator, are used, and in recent years, many combined use generators have been used. However, the AC power supply needs a constant excitation current to compensate the excitation current so as to have a constant voltage characteristic and to obtain stable arc performance as the welding power supply. A device described in Japanese Utility Model Laid-Open No. 61-138400 has been proposed as a moving excitation switching device in this dual-purpose machine. In the welding machine of this device, a relay or the like is generated every time an arc break occurs during welding work. It was switched to the AC power supply by the switching device.

[0003]

Such a generator, which serves as both a general-purpose AC power source and a welding power source, is equipped with two exciting circuits, and can be used as an automatic excitation switching device with a changeover switch or the like depending on the purpose of use. , Each excitation circuit was switched, but whenever the arc was cut during welding, it was switched to the AC side, and the arc performance was poor. An object of the present invention is to provide a brushless synchronous generator for AC power supply / welding that eliminates arc breakage during welding work and obtains stable arc performance. The present invention provides a brushless synchronous generator for AC power supply and welding, which has a simple structure and high reliability.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and a welding armature winding and a welding exciting winding are wound around a stator, and the welding exciting winding is provided. Is connected in series in a delta connection form with three windings wound at equal intervals of about 1/3 of the field pole pitch to form an open delta connection with the terminals open, while the stator is The excitation winding for AC power supply is also wound around, and the output winding of the excitation winding for welding and the excitation winding for AC power supply and the excitation power supply are independent of each other, and the zero-phase current output from the open delta connection is Connected to the exciter machine field winding via a rectifier,
The output of the alternating-current power supply / excitation winding is connected to both ends of the excitation-machine field winding through a rectifier and a control circuit, and the exciter-armature winding, field winding, and rectifier are arranged in the rotor section. However, a current transformer that detects the welding current as a signal for driving the control circuit is provided on the output side of the armature winding for welding, and the signal of this current transformer causes the control circuit to operate when the welding operation is stopped. The above object can be achieved by a constitution characterized in that a stable output is supplied to the AC power source and the welding power source.

[0005]

According to the brushless synchronous generator for AC power supply / welding of the present invention, based on the above configuration, the welding current during the welding operation is detected by the current transformer, and the detection signal is used to control the exciting current control coil for the AC power supply / excitation winding. Current is supplied to the exciter machine field winding through the rectifier by limiting the output and the open delta connection, the exciter machine armature winding is excited, the current is sent to the field winding, and the welding output is matched. The excitation output is generated, and stable welding output is obtained. When an AC power supply is used, the output of the control circuit is controlled to have a constant voltage characteristic, and a current is supplied to the field winding of the exciter machine. As described above, the welding work is smoothly performed in the state where the welding excitation power supply and the AC excitation power supply are connected.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment for automatically controlling the welding power source and the AC power source of the brushless synchronous generator for welding which also serves as an AC power source of the present invention.

Three-phase welding armature windings 16 (O-U, O-V, O-W) and the welding armature windings 16 are wound around the iron core of the stator 17 of the generator. An open delta winding 18 for exciting a welding power source is wound around the same stator core, and terminals of the open delta winding 18 are designated as A and B. The stator 17 is further wound with an excitation winding 6 that also serves as an AC power source and an excitation machine field winding 7. The open delta winding 18
The exciting currents output from the terminals A and B are supplied to the exciting machine field winding 7 via the variable resistor 14 and the rectifier 5 that adjust the welding current.

Further, a part of the excitation winding 6 also serving as an AC power supply is supplied to the control circuit 12 through the exciter field winding 7, the power supply of the control circuit 12 and the rectifier 11 as a voltage detection of the AC power supply, and is excited. It is output to the machine field winding 7. On the other hand, rotor 19
A field winding 8 and an exciter armature winding 9 are wound around the iron core, and a rectifier 15 is connected in the middle. The windings thus wound are connected as follows.

Reference numeral 3 designates the welding armature winding 16 (OU,
(O-V, O-W) is a rectifier that rectifies the welding output, and a reactor L is interposed between the rectifier and a current transformer 4 that detects a welding current. This rectifier 3
The welding output terminals plus (+) and minus (-) are connected to, the welding rod 1 is connected to the plus terminal, and the base material 2 is connected to the minus terminal. A variable resistor 13 for adjusting the AC power supply output voltage is arranged as a control circuit of the control circuit 12 and is connected between the exciter field winding 7 and the rectifier 5. 1
Reference numeral 0 is an AC power outlet, and reference numeral 15 is a rectifier arranged between the exciter armature winding 9 and the field winding 8 of the rotor 19. Reference numeral 20 is an exciting winding for welding the open delta winding 18.

A brushless synchronous generator for AC power supply / welding of the present invention thus connected will be described with reference to a circuit diagram of an embodiment shown in the drawings. The rotor 19 of the generator is rotationally driven by a drive source such as an engine. This rotor 19
The rotation of the rotor core causes a residual magnetic flux in the rotor core to generate a voltage in the excitation winding 6 which also serves as an AC power source, and the exciter armature winding 9 of the rotor 19 is crossed with this voltage, whereby the exciter armature winding is wound. A voltage is generated on the line 9 and a current flows. This current is rectified by the rectifier 15, and the current flows through the field winding 8,
Magnetic flux is generated, and this is generated by the armature winding 1 for welding the stator 17.
6 (O-U, O-V, O-W) and the excitation winding 6 also serving as an AC power supply are cross-linked to generate a voltage.

Next, when the welding rod 1 and the base material 2 which are respectively connected to the welding output terminals plus and minus are brought into contact with each other and an arc welding operation is performed, this welding current is detected by the current transformer 4 and controlled. The output is limited by the circuit 12, the voltage from the open delta winding 18 is applied to the exciter machine field winding 7 via the variable resistor 14 and the rectifier 5, and the exciting output commensurate with the welding output is opened. A stable welding output is generated in the wire 18, and the welding current is supplied to the welding output terminal through the rectifier 3.

When the base material 2 and the welding rod 1 are separated from each other and the welding work is interrupted, the control circuit 12 operates because there is no signal from the current transformer 4, and the current of the exciting winding 6 that also serves as the AC power source excites the exciter machine. It is supplied to the field winding 7. The control circuit 12 has an output adjusting function. Therefore, an exciting current corresponding to the AC rated output is flowing through the exciter field winding 7, and the load characteristic is maintained at a constant voltage. Further, the tap C is taken out from an appropriate place of the AC power supply / excitation winding 6 and serves as an AC side output excitation power supply.

The welding brushless synchronous generator also used as an AC power supply of the present invention is generated by the AC power supply / excitation winding 6, and is generated by the open delta winding 18 from the voltage applied to the exciter field winding 7, and is excited. Since the voltage applied to the machine field winding 7 becomes low, the welding output and the AC output can be adjusted even when the welding-side excitation power supply and the AC-side excitation power supply are connected. The welding brushless synchronous generator that also serves as an AC power source according to the present invention has a constant voltage characteristic of the AC power source and a drooping characteristic of the welding power source.
Three different external characteristics are required. In the case of an AC power supply, a constant voltage characteristic can be obtained from the excitation winding 6 also serving as an AC power supply via the control circuit 12. At this time, open delta winding 1
The voltage generated by 8 and applied to the exciter field winding 7 is designed to be lower than the voltage applied to the exciter field winding 7 and lower than the voltage applied to the exciter field winding 7 within the rated output. There is. That is, although it has a shunt winding characteristic, an exciting current is supplied from the open delta winding 18 at the time of a sudden short circuit,
Maintain short circuit current. Further, in the case of a welding power source, the output voltage is reduced by the armature reaction of the generator and the drooping characteristic is obtained by the three-phase reactor.

Therefore, the voltage of the excitation winding 6 that also serves as the AC power source and is supplied to the control circuit 12 drops at the time of arc start,
Arc start is impossible. In the case of a welding power source having a drooping characteristic, a constant stable excitation power source or an excitation power source commensurate with the welding output is required. In this case, the third harmonic generated when a welding current flows through the armature winding 16 for welding. The wave magnetic flux generates a voltage in the open delta winding 18. This voltage has a series winding characteristic, and a stable excitation power supply can be obtained. The variable resistor 13 for adjusting the AC power supply voltage is for ac output of 50 Hz and 60 Hz. By adjusting the variable resistor 13, a 110 V or 220 V power source can be easily obtained.

As described above, according to the welding brushless synchronous generator for AC power supply of the present invention, when the welding power supply is supplied, the welding work is stably performed while being adjusted by the open delta winding 18, and the AC power supply is used. When used, the welding output current is not detected, so that it is adjusted by the control circuit 12 and the current of the electric tool or the like is supplied.

[0016]

With the above structure, the series winding characteristic can be obtained from the open delta winding, and the separately-excited power source such as the dynamo and the battery is not required. In the conventional welding machine, the arc performance is poor because the AC power source is switched to the AC power source by a relay etc. every time an arc breakage occurs during the welding work, but the AC power source / welding brushless synchronous generator of the present invention has an open delta The arc performance is significantly improved by the third harmonic magnetic flux generated by the winding. Therefore, it is possible to provide a highly reliable AC brushless synchronous generator for AC power supply with a simple structure.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment for automatically controlling a welding power source and an AC power source of a brushless synchronous generator for AC power source / welding according to the present invention.

[Simple explanation of symbols]

 1 Welding rod 2 Base material 3 Rectifier 4 Current transformer 5 Rectifier 6 AC power source / excitation winding 7 Exciting machine field winding 8 Field winding 9 Exciter armature winding 10 Outlet 11 Rectifier 12 Control circuit 13 Variable resistance Unit 14 Variable resistor 15 Rectifier 16 Welding armature winding 17 Stator 18 Open delta winding 19 Rotor 20 Welding excitation winding

Claims (1)

[Claims] 1. A stator is wound with a welding armature winding and a welding excitation winding, and the welding excitation winding is wound at equal intervals of about 1/3 of the field magnetic pole pitch. Three windings are connected in series in the form of a delta connection to form an open delta connection with the terminals open, and on the other hand, an exciting winding that also serves as an AC power source is wound around the stator, and an exciting winding for welding and The output winding of the AC power supply / excitation winding and the excitation power supply are independent of each other, and the zero-phase current output from the open delta connection is connected to the exciter field winding via a rectifier, and also serves as the AC power supply. The output of the exciting winding is connected to both ends of the exciting machine field winding through a rectifier and a control circuit, and the exciting machine armature winding, the field winding and the rectifier are arranged in the rotor section, and the control is performed. For welding a current transformer that detects the welding current as a signal to drive the circuit It is provided on the output side of the armature winding, and by the signal of this current transformer, the control circuit is operated when the welding work is stopped, and a stable output is supplied to the AC power source and the welding power source. Brushless synchronous generator for AC power supply and welding.