JPH0226771B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an AC electromagnet used in electrical equipment such as electromagnetic relays.

Conventionally, when designing AC electromagnets, a spring method has been adopted as the return method. Therefore, the load characteristics become linear, and the attraction force of the electromagnet needs to be increased, resulting in a problem that the power consumption of the electromagnetic coil inevitably increases.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks and provide an AC electromagnet with reduced power consumption.

The AC electromagnet of the present invention is characterized in that it utilizes the magnetic force of a permanent magnet for return in order to achieve the above object.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

FIG. 1 is a perspective view of an AC electromagnet showing an embodiment of the present invention.

In FIG. 1, reference numerals 1a and 1b are U-shaped iron cores, which are connected by resin 2. As shown in FIG. The resin 2 magnetically isolates the iron cores 1a and 1b from each other. Notches 3a, 3b are provided in the U-shaped central sides of the iron cores 1a, 1b, and permanent magnets 4a, 4b are provided.
is installed. If only the above iron core portion is illustrated, it will be as shown in FIG. 2.

In FIG. 1, reference numeral 5 denotes an excitation coil that is wound across both of the iron cores 1a and 1b via a spool 6, and only the part where the excitation coil 5 is wound around the iron core shown in FIG. 2 is shown. Then, the partially cutaway perspective view of FIG. 3 is obtained.

Furthermore, in FIG. 1, 7a and 7b are armatures, the armature 7a corresponds to both U-shaped tips 8a1 and 8a2 of the iron core 1a, and the armature 7b corresponds to both U-shaped tips 8b1 and 8b2 of the iron core 1b, respectively. It is being constructed. Also Amachiyua 7
a and 7b are connected by resin 9 and are magnetically shielded. A permanent magnet 10 supported by resin 9 is placed between armatures 7a and 7b.
are provided facing the U-shaped tips 8b1 and 8b2 of the iron core 1b. If only the armatures 7a and 7b connected by the resin 9 are taken out and illustrated, the result will be as shown in FIG. 4. Conversely, the excitation coil 5 shown in FIG. 3, the armature 7a shown in FIG.
7b and the permanent magnet 10 are combined to complete the AC electromagnet shown in FIG.

Next, the operation of the AC electromagnet configured as described above will be explained.

First, the operation and characteristics of the magnetic circuit composed of the iron core 1b including the permanent magnet 4b, the armature 7b, and the excitation coil 5 will be described.

Now, as shown in FIG. 5, S of the permanent magnet 4b
Assume that the pole is on the left and the N pole is on the right. When the excitation coil 5 is in a non-excited state, the magnetic flux generated by the permanent magnet 4b passes through the inside of the iron core 1b, so that the magnetic flux flows through the iron core 1b.
It will not leak outside. Therefore, the armature 7b is not affected by the attractive force due to the magnetic flux of the permanent magnet. However, when a current flows through the exciting coil 5 and the right tip 8b1 of the iron core 1b becomes the north pole and the left tip 8b2 becomes the south pole, the magnetic flux generated in the exciting coil 5 flows from left to right inside the iron core 1b. The direction of the magnetic flux produced by this excitation coil 5 is opposite to the magnetic flux of the permanent magnet 4b within the iron core 1b. Therefore, the magnetic resistance within the iron core increases due to excitation, and the magnetic flux of the permanent magnet 4b, which passed through the inside of the iron core before excitation, passes through the armature 7b. This permanent magnet 4
Due to b, the magnetic flux passing through the armature 7b flows from right to left, and is in the same direction as the magnetic flux caused by the excitation coil 5. Therefore, the magnetic flux flowing through the armature 7b is the magnetic flux due to the excitation coil 5 and the permanent magnetic flux 4b.
It is the sum of the magnetic flux due to

When the excitation direction by the excitation coil 5 is reversed in the next half cycle and the right tip 8b1 of the iron core 1b becomes the S pole and the left tip 8b2 becomes the N pole, the direction of the magnetic flux passing through the iron core 1b becomes from right to left, and is permanently The direction is the same as the direction of the magnetic flux generated by the magnet 4b. Since the maximum amount of magnetic flux passing through the iron core 1b is constant, the magnetic flux generated by the excitation coil 5 quickly saturates at a small value. Therefore, the magnetic flux flowing through the armature 7b is also very small. As a result, as shown in FIG. 6, the magnetic flux φ2 flowing through the armature 7b becomes asymmetric in positive and negative directions, biased toward the positive side (N pole side), even though the excitation current I is a sinusoidal alternating current.

On the other hand, the magnetic circuit composed of the iron core 1a including the permanent magnet 4a, the armature 7a, and the excitation coil 5 is also similar to the above, except that the phase is shifted by 180 degrees due to the polarity of the permanent magnet 4a being opposite to that of 4b. With this operation, the magnetic flux φ1 shown in FIG. 6 flows through the armature 7a.

Next, the operation including the permanent magnet 10 for return will be explained.

Figure 7 shows amateurs 7a and 7 when not energized.
The position of b is shown. It is assumed that the N pole of the permanent magnet 10 is on the right and the S pole is on the left. In the non-excited state, the magnetic flux φm of the permanent magnet 10 passes through the air gap to the iron core 1.
This magnetic force creates an attractive force between the permanent magnet 10 and the tip 8b1 of the iron core 1b, which returns the armatures 7a and 7b to the return position, that is, the second armature. Hold it in the position shown in Figure 7.

Figure 8 shows amateurs 7a and 7b during excitation.
It shows the position of.

Now, when an excitation current of I is applied to the excitation coil 5,
The composite magnetic flux φ2 of the magnetic flux generated by the exciting current I and the magnetic flux generated by the permanent magnet 4b becomes large when the magnetic flux generated by the exciting current I passes from left to right within the iron core 1b. That is, as shown in FIG. 6, it is biased toward the N pole side. This magnetic flux φ2
Therefore, the tip 8b1 of the iron core 1b becomes the north pole, and the tip 8b2 becomes the south pole. As a result, the N of the permanent magnet 10
The pole and the north pole of the tip 8b1 of the iron core 1b are of the same polarity and repel each other, and the permanent magnet 10 attempts to move from its return position. Therefore, if the distance between the iron core 1b and the armature 7b is made shorter than the distance between the iron core 1b and the armature 7a in advance, the iron core 1
b attracts amateur 7b. At this time, the repulsive force between the permanent magnet 10 and the iron core 1b promotes the attraction of the armature 7b.

On the other hand, when the magnetic flux φ2 shows a large value on the north pole side due to the exciting current I, the magnetic flux φ1 passing through the armature 7a via the iron core 1a due to the exciting current I and the permanent magnet 4a is small as shown in FIG. It is saturated at a value of Therefore, the attraction of the armature during this cycle of the excitation current is mainly achieved by attraction between the iron core 1b and the armature 7b.

However, when the excitation current moves to the next half cycle and the magnetic flux passing through the iron core due to this excitation current moves from right to left, the magnetic flux generated in the iron core 1a and armature 7a is biased toward the S pole side, contrary to the previous half cycle. Since the magnetic flux φ1 is large, amateurs are attracted to iron core 1.
The main ones are a and amateur 7a.

As long as the excitation current continues to flow in this way, the armatures 7a and 7b will remain connected to the iron cores 1a and 1 as shown in FIG.
It is adsorbed and held by b.

The attraction and holding action of the armatures 7a and 7b is such that even if the magnetic flux of one is 0 and the attraction is 0, the magnetic flux of the other armature is not 0 and the attraction force is also not 0. Therefore, one of the armatures is attracted and held during excitation. , no groaning occurs.

When the excitation current is set to 0 and the excitation is released, the magnetic flux φ1,
The attraction force due to φ2 disappears, and the armatures 7a, 7b return to the state shown in FIG. 7 due to the attraction force due to the magnetic flux φm of the permanent magnet 10.

In the above embodiment, the case where the permanent magnet for return is provided on one core side of a pair of iron cores has been described, but as shown in FIG. 9, the permanent magnet for return 1
In addition to 0a, 10b may also be provided. In this way, by providing a pair of permanent magnets for return, the return force can be increased.
Furthermore, the repulsive force of the permanent magnet at the moment of excitation can be strengthened.

As described above, according to the AC electromagnet of the present invention, a notch is provided at the center side of the U-shaped iron core, and a first permanent magnet is fitted into each of the notches, while a first permanent magnet is fitted in the vicinity of at least one of the pair of armatures. Since the second permanent magnet is arranged to face the tip (magnetic pole) of at least one of the pair of iron cores, the magnetic force of the permanent magnet can be used to return the second permanent magnet to the original position. Unlike the spring return type, there is no need to flow a large current during excitation, so power consumption can be reduced.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an AC electromagnet showing an embodiment of the present invention, Fig. 2 is a partial perspective view of the AC electromagnet shown in Fig. 1 with only the iron core taken out, and Fig. 3 is the one shown in Fig. 2. FIG. 4 is a partial perspective view of the AC electromagnet shown in FIG. 1 with only the armature part taken out, and FIG. 5 is a partial perspective view of the embodiment shown in FIG. 1 for explaining excitation characteristics. Part cutaway side view, Figure 6 is a waveform diagram showing exciting current and magnetic flux,
FIG. 7 is a partially cutaway plan view showing the position of the armature when not energized, FIG. 8 is a partially cutaway plan view showing the position of the armature when energized, and FIG. 9 is an AC showing another embodiment of the present invention. FIG. 3 is a partially cutaway plan view of the electromagnet. 1a, 1b... Iron core, 5... Excitation coil, 7
a, 7b... amateur, 8a1, 8a2, 8b
1,8b2... Tip of iron core (magnetic pole), 10...
permanent magnet.

Claims (1)

[Claims] 1. A pair of magnetically isolated U-shaped cores 1
a, 1b, an excitation coil 5 wound around both iron cores 1a, 1b, and the pair of iron cores 1a, 1b.
In an AC electromagnet consisting of a pair of connected armatures 7a, 7b which are provided corresponding to the U-shaped cores 1a, 1b and are magnetically isolated, a notch 3 is provided at the center side of the U-shaped cores 1a, 1b.
a, 3b are provided, and first permanent magnets 4a, 4b are fitted into these notches, respectively, while a second permanent magnet is provided near at least one of the pair of armatures 7a, 7b.
A permanent magnet 10 is provided, and this second permanent magnet 10
An alternating current electromagnet comprising: a magnetic pole portion of at least one of the pair of iron cores 1a, 1b.