JPH0540697Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a generator for arc welding, and more particularly to an improvement of a rotating field type generator for welding.

[Prior Art] In general, welding work sites require power supplies for power tools and lighting in addition to the welding power source. Therefore, in this type of site, a rotating field type welding generator is used as a welding generator that also serves as a commercial frequency alternating current generator.

The above-mentioned welding generator can be made into a single unit by wrapping a welding power source winding in addition to the AC power source winding that is wound around the armature of a conventional rotating field type AC generator. It is configured so that both commercial frequency AC power and welding power can be obtained from the generator. In addition, the generator described above has the ability to generate power from both power sources and has a simple configuration, so it has become popular in recent years due to its advantages such as the ability to use production equipment for general rotating field alternating current generators as is for mass production. This is something that is just beginning.

[The problem that the idea aims to solve]

However, conventionally, this type of generator was originally designed for commercial frequency AC power generation, and due to structural constraints to obtain this commercial frequency output, the frequency of the welding power source was also 60Hz. Or 50Hz
becomes. Therefore, even if this is converted to direct current using a rectifier, single-phase full-wave rectified output has the disadvantage that current pulsations are large and the arc tends to become unstable. Also, even when using multiphase full-wave rectified output,
The voltage recovery characteristics, which will be described later and are essential for arc stability, become poor.

That is, to explain this type of conventional example with drawings, Fig. 1 shows an example of a conventional rotating field type welding generator, and Fig. 2 shows an oscilloscope showing the voltage recovery characteristics of the generator of Fig. 1. In the graph, FIG. 3 is also a wiring diagram.

an armature core 2 having an armature groove 1 on its inner diameter surface;
The rotating shaft 5 is inserted into the inner diameter part of the armature core 2.
The rotor core 3, which is fixedly attached to the rotor core 3 and equipped with the field winding 4, is exactly the same as that of a normal rotating field type AC generator, so the armature groove 1 is connected to the commercial frequency AC power source. A welding power source winding and a welding power source winding (both not shown) are wound together. For the field winding 4, a separately excitation type is shown in FIG. 3, but a self excitation type is also adopted. FIG. 2 is an oscillograph showing the voltage recovery characteristics of this conventional generator. The vertical axis represents the terminal voltage e, and the horizontal axis represents time t. The AC output is converted to DC output by the main rectifier 11. Under this condition, the voltage recovery curve A shows that the initial value of the voltage S at the time of short circuit is 20 at the output terminal 12 immediately after the voltage S suddenly becomes unloaded.
It is expressed as a voltage value E of about (V). In this case, the higher the voltage value E at the initial point, the more sufficient the voltage recovery from fluctuations in the arc voltage that occur frequently during welding work, and the more stable the arc can be generated. Voltage value E that can maintain this arc stably
Normally, 30 (V) or more is required, but in a conventional rotating field type welding generator, the transformer type reactor 1
If there is no external additional device such as 3, the voltage value E is 20
(V) It becomes less than that. This is because the voltage recovery characteristics of the generator against instantaneous changes in arc voltage are poor, causing arc cuts and making it impossible to perform good welding work. Therefore, in order to prevent this arc cut, if a large-scale external additional device such as a transformer type reactor 13 or a single-wound type reactor inserted between the main rectifier 11 and the output terminal 12 is installed as shown in FIG. Contrary to the above-mentioned advantages, there are problems such as an overall increase in weight and an increase in costs.

Therefore, in view of the above problems, the present invention eliminates the need for large-scale external additional equipment such as a transformer type reactor, has good voltage recovery characteristics, is less likely to cause arc cut, and provides stable arc generation for welding. The purpose of the present invention is to provide a rotating field type generator that can significantly improve the working efficiency of the generator.

[Means and actions to solve the problem]

The present invention was made to achieve the above object, and is a rotating field type equipped with a winding for a commercial frequency AC power source that outputs power at a commercial frequency, and a winding for a welding power source for extracting welding output. In a welding generator, a plurality of rotor grooves are formed in the polar arc of each magnetic pole head of the rotor, and a high-frequency power supply winding is wound around the armature core. A high-frequency electromotive force is induced in the high-frequency power source winding due to a change in reactance, and after rectifying the high-frequency electromotive force, the welding output obtained by rectifying the electromotive force of the welding power source winding has a mutual The output voltages are superimposed so that they are added to each other.

〔Example〕

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

FIG. 4 shows a front view of the main part of the present invention, and the inner peripheral part of the armature core 2 has a large number of armature grooves 1 when viewed from the front.
and salient pole portions are provided around the periphery, and each armature groove 1 extends in the axial direction when viewed from the side. A winding for a commercial frequency AC power source and a winding for a welding power source (both not shown) are wound together in this armature groove 1. As in the past, output is taken out from the commercial frequency AC power supply winding as a power source for power tools and the like. Further, a rotary shaft 5 is inserted into the core of the armature core 2 in the axial direction, and a rotor core 3 is rotatable by forming a gap 6 between the rotary shaft 5 and the armature core 2. is permanently installed.
A field winding 4 is wound around the rotor core 3 in the same manner as in the prior art, and a two-pole field is formed by supplying an exciting current to the field winding 4. A large number of rotor grooves 8 are provided around the outer periphery of the polar arc of each magnetic pole head of the rotor core 3 so that the rotor grooves 8 and the salient pole portions 7 have approximately the same width when viewed from the front. Each rotor groove 8 extends in the axial direction when viewed from the side. Between each rotor groove 8, salient pole portions 7 having approximately the same width as the rotor groove 8 are formed in a residual manner by maintaining the original polar arc. Further, the armature core 2
In the armature groove 1, the change in air gap length due to the presence of the rotor groove 8 and the salient pole portions 7 formed in the rotor core 3, that is, the pulsation of magnetic flux, is determined by the number of salient pole portions 7 and the rotor core 3. In order to induce a high frequency electromotive force proportional to the product of the rotation speed and the rotation speed, high frequency power supply windings 9a, 9b, 9c and 9d having appropriate winding pitches are wound at intervals.

In addition, as shown in the wiring diagram of FIG. 6, this high frequency power supply winding has a series circuit consisting of 9a and 9b,
They are connected in parallel to the series circuit consisting of 9c and 9d via the superimposed output rectifier 11a, and are connected to the output terminal 12 of the welding power source winding 10 as a parallel circuit. Therefore, the high-frequency power output from the superimposed output rectifier 11a can be superimposed on the welding power output from the main rectifier 11 that rectifies the output from the welding power supply winding 10 so as to be added to each other. The field winding 4 is shown in FIG. 6 as being supplied with excitation current from a variable excitation power source for convenience, but as an excitation power source, in addition to external excitation, a winding for commercial frequency AC power supply Of course, it is also possible to adopt a self-excitation method which has been widely used in the past, such as supplying excitation current to the output via an automatic voltage regulator.

Based on the above configuration and wiring diagram, the rotating field type welding generator of the present invention has a voltage The recovery characteristics become as shown in the oscilloscope shown in FIG. That is, when the vertical axis represents the terminal voltage e and the horizontal axis represents the time t, the voltage recovery curve B immediately after the drop in the short circuit voltage S is on the conventional voltage recovery curve A, with the rotor groove 8 and the salient pole portion 7
As a result of the superimposition of the high-frequency electromotive force obtained from the change in reactance due to
(V) appears on the output terminal 12 side shown in FIG. 6 as a voltage value E exceeding (V). In this way, the voltage recovery curve B appears higher than the conventional voltage recovery curve A, so that it is possible to weld with a higher voltage recovery curve B overall. Therefore, good welding characteristics due to stable arc can be maintained.

In addition, since the rotating field type welding generator according to this invention clearly has two poles for the commercial frequency AC power supply winding and the welding power supply winding, for example, the rotor core 3 can be rotated at 3600 (rpm) or By rotating at 3000 (rpm), an output of 60 (Hz) or 50 (Hz) can be obtained. Therefore, it is possible to reliably maintain the original function as a rotating field type welding generator.

[Effect of idea]

As explained above, this idea is based on the rotor core 3.
A rotor groove 8 is formed on the polar arc surface of the magnetic pole head,
In addition, the armature groove 1 has high frequency power supply windings 9a to 9.
By additionally winding d, the basic structure of the conventional rotating field type power generation system is not changed, and while the manufacturing advantages of its simple structure are maintained, large-scale external additional equipment is not required. The high-frequency electromotive force of the high-frequency power source winding is superimposed on the welding output output from the welding power source winding, resulting in a high voltage recovery curve, which results in stable arc generation. This has the effect of greatly improving welding efficiency.

[Brief explanation of the drawing]

Figure 1 is a front view of the main parts of a conventional rotating field type welding generator, Figure 2 is an oscillograph showing the voltage recovery characteristics of the generator in Figure 1, and Figure 3 is the connection of the generator. Figure 4 is a front view of the main parts of the rotating field type welding generator according to the present invention, Figure 5 is an oscillograph showing the voltage recovery characteristics according to the embodiment of the present invention, and Figure 6 is the power generation according to the present invention. It is a wiring diagram of the machine. 1... Armature groove, 2... Armature core, 3... Rotor core, 4... Field winding, 5... Rotating shaft, 6...
...Gap, 7...Salient pole portion, 8...Rotor groove, 9a~
9d...Winding for high frequency power supply.

Claims (1)

[Claims for Utility Model Registration] An armature core having a circular hollow, and rotation that is fitted into the circular hollow of the armature core to form a gap between the inner periphery of the armature core. a rotor, a winding for a commercial frequency AC power source that outputs a commercial frequency current, and a winding for a welding power source for taking out a welding output, which are wound around the circumference of the armature core. In the field-type welding generator, a large number of rotor grooves are arranged around the outer periphery of the polar arc of each magnetic pole of the rotor so that the rotor groove and the salient pole part have approximately the same width when viewed from the front. and the rotor groove extends in the axial direction when viewed from the side, while a large number of armature grooves and salient pole portions are provided around the inner periphery of the armature core when viewed from the front; and the armature groove extends in the axial direction when viewed from the side, so as to output a high frequency voltage in response to changes in pulsation of magnetic flux generated by rotation of the rotor.
A high frequency power winding is wound in the armature groove, a superimposed output rectifier for rectifying the high frequency output is connected to the high frequency power winding, and a main rectifier for rectifying the output of the welding power source winding. A rotating field type welding generator, characterized in that an output terminal of the rectifier for superimposed output is connected to an output terminal of the rectifier for superimposed output so that their respective outputs add to each other.