JPH0516867Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention is intended for use in armature windings when performing welding, etc. using an inductor generator, especially an inductor generator driven by an engine, etc. By installing the excitation winding in a position where it is less affected by the electromotive force caused by the flowing load current, and rectifying the alternating current voltage generated in the excitation winding and applying it to the field winding, it is possible to create a separately excited generator. This invention relates to an inductor generator that provides drooping characteristics suitable for welding, etc. by providing similar characteristics, and also allows the electromagnetic force generated on the armature to act uniformly.

(Technical Background and Problems) Conventionally, when performing welding by rectifying the AC output from an inductor generator driven by an engine,
A field is applied from another DC power source so that a current with appropriate drooping characteristics flows during short circuits and welding.
So-called external excitation is often used.

However, some types of inductor generators are configured to be self-excited, with an excitation winding superimposed on the slot around which the armature winding is wound to obtain DC power for excitation, and the excitation winding The AC output generated by this is rectified and sent to the field winding. this is,
This is because a separate and independent power source is not required compared to the separately excited case.

However, in the case of the self-excitation type, when a short circuit occurs during welding, etc., the AC voltage generated in the excitation winding decreases due to the influence of the short circuit current flowing through the armature winding, causing the field There was a problem in that the magnetic flux decreased and the current flowing through the armature winding further decreased, resulting in so-called winding characteristics unsuitable for welding.

Furthermore, due to the nature of an inductor generator driven by an engine, when there is no load, the engine is generally placed in an idling state in which the engine speed is lowered in order to save fuel. Therefore, in an idling state, the output voltage of the inductor generator becomes low, making it difficult to start welding immediately, and it is complicated to start welding after increasing the rotational speed to the rated speed.

Furthermore, in order to allow multiple workers to perform welding work at the same time, multiple independent armature windings are arranged within one field winding on the generator stator, and the output of each armature winding is Each signal is rectified by an independent rectifier to obtain a plurality of independent outputs.

Conventionally, when one person uses 1/2 of the total output, or when two people weld at the same time, for example four armature windings are placed along the inner circumference of the generator stator. Assuming that windings A, B, C, and D are independently wound in that order, 1/2 of the total output is taken out using adjacent armature windings A and B, and the remaining Using armature windings C and D, 1/ of the total output
A wiring method was used to take out 2. In this conventional wiring method, if the outputs of armature windings C and D differ from the outputs of armature windings A and B,
In other words, if the load current flowing through the armature windings A and B differs from the load current flowing through the armature windings C and D, a magnetic imbalance will occur due to armature reaction, and the attractive force applied to the inductor will increase. It had the disadvantage of becoming unbalanced, causing increased vibration and magnetic vibration noise. Further, in the case of a two-pole inductor type generator, the magnetic circuit for the field becomes long, and losses within the iron core due to fluctuations in magnetic flux increase.

(Purpose and structure of the invention) The purpose of the invention is to solve the above problems, and the excitation winding is provided at a position where it is less affected by the electromotive force caused by the load current flowing through the armature winding. In addition, by providing a changeover switch that allows the load current to flow evenly through the armature windings depending on the load used, it is possible to obtain drooping characteristics suitable for welding with a simple configuration, and at the same time to reduce armature reaction. The object of the present invention is to provide an inductor generator that allows the electromagnetic force based on the electromagnetic force to act uniformly. Therefore, the inductor generator of the present invention includes an inductor that is coaxially fixed to a rotating shaft and has magnetic poles formed on its outer peripheral surface, and a cylindrical armature core that is provided facing the magnetic poles of the inductor. , a three-phase armature winding wound around the armature core, an excitation winding provided facing the magnetic pole of the inductor and wound around the armature core, and the three-phase armature winding. and a field winding that applies a field to each of the excitation windings, and each of the three-phase armature winding, the excitation winding, and the field winding constitutes a power generation unit. In an inductor generator configured with four sets, the excitation winding of each set is such that the magnetic flux generated by the armature current flowing through the three-phase armature winding of the set is transmitted through the magnetic poles of the inductor. unlinked,
The three-phase armature winding is wound in a slot different from the slot in which it is wound, and two of the four power generation units are symmetrical to each other with the inductor in between. the output terminals are connected in parallel, and the output terminals are connected in parallel, and each output terminal of the group connected in parallel is It is characterized in that a changeover switch is provided between the terminals to freely connect and disconnect the output terminals. This will be explained below with reference to the drawings.

(Embodiment of the invention) Fig. 1 is a sectional view of an embodiment of an inductor generator according to the invention, and Fig. 2 shows a configuration of an embodiment in which the inductor generator according to the invention is used in an engine welder. Fig. 3 shows an embodiment of the configuration of the armature winding section and rectifier circuit section shown in Fig. 2, which are switched by a changeover switch according to the usage of the load, and Fig. 4 explains the inductor generator according to the present invention. An explanatory diagram, FIG. 5 shows an explanatory diagram illustrating a conventional inductor generator.

In the figure, 1 is an inductor, 2 is an armature core, 3 is a field winding, 4, 5, and 6 are excitation windings, 7 is an inductor generator, 8 is an engine, 9 is a battery, and 10 is a current detection 11 is a delay circuit, 12 is an armature winding section, 1
3 represents a rectifier circuit section, and 14 and 15 represent output terminals.

Before explaining one embodiment of the present invention, the windings and slots of a conventional inductor generator will be explained using FIG.

FIG. 5A shows an overview of the inductor, armature winding, excitation winding, and field winding of a conventional three-phase inductor generator.

In the figure, reference numeral 1 denotes an inductor, which rotates in the direction of the arrow by an engine or the like, and is made of a magnetic material such as iron.

2 in the figure is an armature core, and in this example, three-phase (U, V, and W phases) armature windings u, v, and w.
A slot for winding the field winding 3 and a slot for winding the field winding 3 that provides a DC field are provided. 3-phase armature winding, e.g. armature winding w
An excitation winding 4 for self-excitation is provided superimposed on the slot for winding.

In the inductor generator configured in this way, the magnetic flux generated by energizing the field winding 3 circulates through the magnetic poles of the armature core 2 and the inductor 1. is driven in the direction of the arrow by an engine or the like, the magnetic poles of armature core 2 and inductor 1
The magnetic resistance between the magnetic poles provided on the
Out-of-phase voltages in the form of three-phase alternating current voltages are generated in the three-phase armature windings u, v and w, respectively. At this time, an alternating current voltage is also generated in the excitation winding 4 wound in the same slot as the armature winding w, and this voltage is rectified and supplied to the field winding 3 in a so-called self-excitation type. It is structured as follows.

For this reason, for example, when a short circuit occurs when rectifying and welding the three-phase AC voltage generated in the three-phase armature windings u, v, and w, the armature windings u, v
A short circuit current flows through and w, the magnetic flux decreases due to armature reaction, and the alternating current voltage generated in the excitation winding 4, which is wound in the same slot as the armature winding w, decreases, causing the field winding 3 to There is a problem in that the supplied current decreases, and the current at the time of short circuit decreases as shown in the characteristic shown in FIG. 5B.

Therefore, in the present invention, the short-circuit current is reduced between the armature windings u and v by appropriately adjusting the pole pitch of the inductor without winding the excitation winding in the slot in which the armature winding is wound. A unique slot is newly provided at a position where the winding wire for self-excitation is wound in a position where it is less affected by the armature reaction even if the winding current flows through the windings 1 and 2. Further, if necessary, the first excitation winding is wound in the unique slot, and the excitation winding shown in FIG. 2 is further wound in another slot.
By using the voltage generated in the second excitation winding to increase the output voltage during idling, welding etc. can be started immediately from the idling state. Further, the armature reaction is operated so as to balance the imbalance of electromagnetic force caused by the armature reaction as much as possible. The present invention will be explained below.

In FIG. 4A, numerals 1 to 3 are the same as or equivalent to those shown in FIG. 1, so their explanation will be omitted.

In the figure, 5 is a first excitation winding for self-excitation, which is related to the present invention. The excitation winding 5 is wound in a slot provided independently from the slot in which the armature winding is wound. Therefore, even if the armature winding u,
Even if a short circuit current flows through v and w, the output voltage generated in the excitation winding 5 hardly decreases, and a predetermined direct current can be supplied to the field winding 3.
For this reason, the drooping characteristic of the inductor generator of the present invention becomes a substantially constant current characteristic regardless of the voltage when a short circuit current flows, as shown in FIG. 4B, and is suitable for welding.

In addition, in the case where the inductor generator of the present invention is used as an engine welder and the engine is kept in an idling state during no load to save fuel, the excitation winding 5 for self-excitation or a separately provided The voltage generated in the first excitation winding 5 and the second excitation winding 5 are rectified and the voltage generated in the first excitation winding 5 and the second excitation winding 6 are rectified.
A current is supplied to the field winding 3 in a superimposed manner with the excitation winding 6 of the field winding 3, and the output voltage is increased to a predetermined voltage, for example, approximately 45 volts, which is a voltage suitable for starting welding. Make it weldable.

FIG. 1 shows a sectional view of one embodiment of the present invention, and shows the case of a three-phase, four-pole inductor generator provided with a dedicated slot for housing an excitation winding for self-excitation.

In the figure, 1 to 3, 5, and 6 correspond to those in FIG. 4, and u ₁ to u ₄ , v ₁ to v ₄ and w ₁ to w ₄
correspond to u, v, and w in FIG. 4, respectively.

The armature windings u ₁ , v ₁ and w ₁ are wound at positions opposite to the armature windings u ₃ , v ₃ and w ₃ across the inductor 1, and the armature windings u ₂ , v ₂ and
W ₂ is wound at a position facing the armature windings u ₄ , v ₄ and w ₄ with the inductor 1 in between.

As the convex part of the inductor 1 rotates to the right, the magnetic flux interlinking with the three-phase armature windings, for example, u ₁ , v ₁ , w ₁ and the magnetic flux interlinking with the excitation windings 5 and 6 change. generate alternating current voltage. That is, by passing a DC current through the field winding 3, the armature core 2 and the inductor 1
A magnetomotive force corresponding to the product of the number of turns of the field winding 3 and the current is applied between the magnetomotive force and the value obtained by dividing the magnetomotive force by, for example, the magnetic resistance of the wound magnetic pole part of the excitation winding 5. It becomes magnetic flux. Therefore, for example, the excitation winding 5
The voltage generated is generated as the above-mentioned alternating current voltage when the magnetic resistance changes between the armature core 2 and the inductor 1 when the inductor 1 rotates. The alternating current output voltage generated in the excitation winding 5 is rectified and supplied to the field winding 3 in a self-excited form.

The first excitation winding 5 is an armature winding u ₁ , v ₁ or
Since it is wound in a separate slot located away from w ₁ , even if a short circuit current flows through armature windings u ₁ , v ₁ or w ₁ during welding, it will not be affected by the armature reaction. A predetermined output voltage is generated almost unaffected by the decrease in magnetic flux linkage. Therefore, the undesired drooping characteristic that occurs in the conventional self-excitation explained using FIG. 5 is avoided.
It is possible to obtain a material having drooping characteristics shown in FIG. 4B, which is suitable for welding and the like and is similar to that in the case of separately excited.

Further, the excitation winding 6 shown in FIG. 2 is provided to immediately start welding when the inductor generator driven by the engine is in an idling state. That is, a DC voltage obtained by rectifying the AC voltage generated in the excitation winding 6 based on a signal indicating that the engine is in an idling state is applied to the field winding 3, and the first excitation voltage is applied to the field winding 3. Winding 5
so that the direct current from the source is superimposed and supplied.
That is, the output voltages from the armature windings u ₁ , v ₁ , and w ₁ , which decrease during idling, are forcibly increased to a voltage at which welding is possible, for example, 45 volts. Therefore, there is no inconvenience that ignition of welding or the like is started after waiting for example 3 seconds to increase the engine speed from an idling state to the rated speed, unlike in the conventional case.

This is true for other armature windings u ₂ , v ₂ , w ₂
The same holds true for armature windings u ₄ , v ₄ , and w ₄ .

FIG. 2 shows an example configuration in which the inductor generator according to the present invention is used in an engine welder. The wire is wrapped. The armature winding portion 12 will be described in detail in FIG. 3, which will be explained later.

When the inductor 1 is driven by the engine 8, a three-phase AC voltage is generated in the three-phase armature windings u, v, and w. In the illustrated case, current is supplied from the battery 9 to the field winding 3 via a diode so that the voltage rises correctly even when there is no residual magnetism in the armature core 2 or the like. After starting, the DC voltage obtained by rectifying the AC voltage generated in the first excitation winding 5 becomes higher than the battery voltage, so no current is supplied from the battery 9.

The three-phase AC voltage generated in the three-phase armature windings u, v, and w is rectified into three-phase double-wave rectification by the current circuit section 13 and converted into a DC voltage, and then output to the output terminals 14, 1.
5 to the illustrated welding rod and the base material.
The current supplied to the welding rod is passed through a current transformer (CT)
and is input to the current detector 10. The current detector 10 sends out a signal when the load current is not flowing, for example, to activate the solenoid shown so that the engine 8 is in an idling state, and also activates the solenoid shown through the delay circuit 11 to close the contact. The AC voltage generated from the second excitation winding 6 is supplied to the rectifier, and the rectified DC current is supplied to the field winding 3 in a superimposed manner.

By doing so, when there is no load, for example, when the engine 8 is in a standby state where no welding is being performed, the engine 8 is placed in an idling state to save fuel, and the direct current voltage, for example 45 volts, allows immediate welding even in an idling state. Since the generator output voltage is maintained at , there is no need to once raise the engine 8 to the rated speed and wait until sufficient voltage is generated for welding.

In addition, the delay circuit 11 is configured so that the current from the excitation winding 6 is supplied to the field winding 3 in a superimposed manner while the inductor 1 is still rotating at a relatively high speed at the time of idling transition. It plays a role in preventing excessive current flowing into the circuit. Vibration caused by the inrush of the excessive current and excessively increased generator output voltage may cause insulation deterioration of the field winding 3 or armature winding, etc., and the generator may make momentary loud noises. This is provided to prevent this from occurring. That is, when the illustrated solenoid operates based on the signal detected by the current detector 10 to reduce the amount of fuel supplied to the engine 8, for example,
That is, when operation is started to bring the engine into an idling state, the inductor 1 does not slow down until some time passes due to the inertia of the engine 8 or the inductor 1, but the delay circuit 11 causes the inductor 1 to slow down. The superimposed current is supplied to the field winding 3 after a delay of sufficient time, for example, 2 seconds.

FIG. 3 shows an embodiment of the configuration of the armature winding section and the rectifier circuit section of FIG. 2, which are switched by a changeover switch depending on the usage of the load. The armature windings u ₁ , v ₁ , w ₁ in the same figure are wound at opposite positions to the armature windings u ₃ , v ₃ , w ₃ with the inductor 1 in between, as shown in FIG. 1. , armature windings u ₂ , v ₂ , w ₂ are wound at positions opposite to armature windings u ₄ , v ₄ , w ₄ with the inductor 1 in between. A rectifier circuit that performs three-phase full-wave rectification is provided corresponding to each armature winding, and the negative terminals of the rectifier circuits are connected to each other and output terminal 1.
5 or 15'. On the other hand, on the positive side, armature windings u ₁ , v ₁ , w ₁ and armature windings u ₃ ,
It is connected to v ₃ and w ₃ and connected to the output terminal 14. armature winding u ₂ , v ₂ , w ₂ and armature winding u ₄ ,
The positive terminal sides of v ₄ and w ₄ are connected to each other, and the output terminal 1
4' or the output terminal 14 via a changeover switch 16.

Now, when the inductor generator 7 is used by one person, the changeover switch 16 is turned on. At this time, the load current flows almost evenly through the armature windings u ₁ , v ₁ , w ₁ or the electronic windings u ₄ , v ₄ , w ₄ , and the electromagnetic force caused by the armature reaction is balanced. is maintained.

When the inductor generator 7 is used by two people, the changeover switch 16 is turned off and the load is connected to the output terminals 14, 15 and 14', 15'. At this time, a set of armature windings u ₁ , v ₁ , w ₁ and armature windings u ₃ , v ₃ , w ₃ and armature windings u ₂ ,
Since the set of v ₂ , w ₂ and the armature windings u ₄ , v ₄ , w ₄ are independent, the above-mentioned drooping characteristics can be obtained without being influenced by anything else. Furthermore, armature windings u ₁ , v ₁ , w ₁ and armature windings u ₃ , v ₃ , w ₃ and armature windings u ₂ , v ₂ , w ₂ and armature windings u ₄ , v ₄ ,
Since w ₄ is wound opposite to each other with inductor 1 in between, even if there is a difference in the load current between the two, the electromagnetic force due to armature reaction will be balanced.

The above explanation has been about 4 poles in a 2-output system, but in the case of a 2-output system, 4 x N, and in the case of a 3-output system, 6 x N (N is an integer greater than or equal to 1) poles are used as field windings. By winding the armature so that it is symmetrical and using a changeover switch depending on the usage of the load, it is possible to correct the unbalance of electromagnetic force caused by armature reaction.

Also, as is clear from the above explanation, by using multiple poles, the magnetic circuit is shortened, and the inductor 1 is mechanically shortened.
Even if the iron rotates unbalanced, the loss within the iron core is reduced.

(Effects of the invention) As explained above, according to the invention, the excitation winding is wound in the slot provided at a position where the influence of the armature reaction due to the load current flowing in the armature winding of the inductor generator is small. Since the alternating current voltage generated in the excitation winding is rectified and passed through the field winding to generate a field, drooping characteristics such as those shown in Figure 4B, which are suitable for welding, are obtained. It is possible to obtain predetermined characteristics with a simple configuration.

Further, by appropriately switching the changeover switch according to the operating load, it is possible to suppress the generation of vibrations and magnetic vibration noise. By increasing the number of poles, iron loss can also be reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of one embodiment of an inductor generator according to the present invention, Fig. 2 is a configuration of an embodiment in which the inductor generator according to the present invention is used in an engine welder, and Fig. 3 is a load usage. FIG. 2 shows an example configuration of an armature winding section and a rectifier circuit section which are switched by a changeover switch depending on the mode; FIG. 4 is an explanatory diagram illustrating the inductor generator according to the present invention; FIG. 5 shows an explanatory diagram for explaining a conventional inductor generator. In the figure, 1 is an inductor, 2 is an armature core, 3 is a field winding, 4, 5, and 6 are excitation windings, 7 is an inductor generator, 8 is an engine, 9 is a battery, and 10 is a current detection 11 is a delay circuit, 12 is an armature winding section, 1
3 represents a rectifier circuit section, and 14, 14', 15, and 15' represent output terminals.

Claims (1)

[Claims for Utility Model Registration] An inductor that is coaxially fixed to a rotating shaft and has magnetic poles formed on its outer peripheral surface, a cylindrical armature core that is provided facing the magnetic poles of the inductor, and a three-phase armature winding wound around the armature core; an excitation winding provided facing the magnetic pole of the inductor and wound around the armature core; the three-phase armature winding and the above. The three-phase armature winding, the excitation winding, and the field winding each constitute a power generation unit, and the four sets are provided. In the inductor generator configured, the excitation windings of each set are such that magnetic flux generated by armature current flowing through the three-phase armature windings of the set is interlinked via the magnetic poles of the inductor. Never,
The three-phase armature winding is wound in a slot different from the slot in which it is wound, and two of the four power generation units are symmetrical to each other with the inductor in between. the output terminals are connected in parallel, and the output terminals are connected in parallel, and each output terminal of the group connected in parallel is An inductor generator characterized in that a changeover switch is provided between the terminals to freely connect and disconnect the output terminals.