JPS6348167B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an AC electromagnet used in electromagnetic relays and the like.

FIG. 9 shows a conventional AC electromagnet. In this figure, 10 is a U-shaped iron core around which an excitation coil 11 is wound, and 12 is an amateur.
is hinge-supported by one magnetic pole portion 10a of the iron core 10, and the return spring 1 is activated by energizing the excitation coil 11.
3 and is attracted to the other magnetic pole portion 10b. The magnetic pole portion 10b of the iron core 10 is divided into two parts, and a shade coil 14 is provided on one side. FIG. 10 shows the waveforms of the excitation current I and magnetic flux φ of the electromagnet. As can be seen from this figure, in the conventional AC electromagnet, by providing the darkening coil 14, a phase difference is created between the magnetic fluxes φ ₁ and φ ₂ flowing through the darkening portion and the non-shading portion of the magnetic pole portion 10b. ,
When the magnetic flux on one side becomes zero, the magnetic flux on the other side maintains the attractive force between the iron core 10 and the armature 12, thereby preventing the occurrence of whirring.

In the above configuration, the iron core 1
The flatness of the magnetic pole portion 10b of the coil 1 must be strictly regulated.
4 is caulked and fixed to the iron core 10, so the magnetic pole part 10b has an appropriate flatness in relation to the distortion that occurs at that time.
As a result, it takes time to set the flatness of the magnetic pole portion 10b, resulting in high cost. Further, if dust such as iron powder or resin adheres to the magnetic pole portion 10b during use, the phase difference between the magnetic fluxes φ ₁ and φ ₂ decreases, causing whirring. In addition, when used as an electromagnet in a small and thin electromagnetic relay, the rise in temperature inside the relay will greatly affect the characteristics, so the heat generated by the bear coil 14 will also be affected by the relay, similar to the heat generated by the excitation coil 11, etc. This must be considered as a factor in the rise in temperature.

In addition, as another measure to prevent whirring, it is known to use a diode 15 as shown in Fig. 11 and rectify the excitation current I as shown in Fig. 12. There is a risk that the diode 15 will be destroyed, the rectification function will be lost, and a hum will occur.

This invention has been made from the above-mentioned viewpoint, and an object of the present invention is to provide an AC electromagnet that eliminates the need for a dark coil and a diode, prevents the generation of buzzing, suppresses heat generation, realizes cost reduction, and reduces power consumption. It is an object.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a front view of an AC electromagnet according to an embodiment of the present invention. In this front view and the plan view of FIG. 2, 20 is an excitation coil wound around a spool 21, 22 is a yoke, and The yoke 22 has a pair of opposing magnetic pole portions 23a and 23b and is arranged to surround the excitation coil 20. The width of one magnetic pole portion 23a is narrower than that of the other magnetic pole portion 23b. Reference numeral 24 denotes an armature that is swingably supported by a hinge in a recess 26 of the yoke 22 within the hollow portion 25 of the excitation coil 20, that is, the spool 21. As shown in FIGS. 3 and 4, the armature 24 is magnetically isolated from each other by a synthetic resin 27, and is mechanically coupled to a pair of magnetic materials 28, which are attracted to one magnetic pole portion 23b of the yoke 22. 29, and a permanent magnet 30 embedded in a part of one magnetic material 28. Further, a permanent magnet 31 for return that attracts the magnetic material 28 on the side of the permanent magnet 30 to the other magnetic pole part 23a of the yoke 22 is connected to a magnetic circuit 32 between the magnetic pole part 23a of the yoke 22 and the hinge part (recessed part) 26. Inside, along with this magnetic circuit 32, there is a permanent magnet 30 on the armature 24 side.
are arranged so as to face each other with the same polarity.

Next, the operation of the above configuration will be described. Now, the first
As shown in FIG. 3, it is assumed that the N poles of the permanent magnets 30 and 31 are on the top and the S poles are on the bottom. When the coil 20 is not energized, the armature 24 is
The magnetic flux φ ₁ generated by the permanent magnet 30 of the magnetic material 2
8, so the magnetic material 2
There is no leakage to the outside of the armature 24, and the armature 24 is not affected by the attractive force caused by the magnetic flux _φ1 of the permanent magnet 30 at all. Further, the inside of the magnetic material 28 is almost saturated with the magnetic flux φ ₁ generated by the permanent magnet 30, but the magnetic flux φ ₂ of the permanent magnet 31 continues to flow through the magnetic material 28 until the inside of the magnetic material 28 reaches the saturated state. By passing through, the upper end 33a of the magnetic material 28 is attracted and held by the magnetic pole part 23a of the yoke 22, and the armature 24 is held at the return position.

Next, consider the case where an exciting current is passed through the coil 20. When the upper end 33a of the magnetic material 28 becomes the S pole and the lower end 33b becomes the N pole by excitation of the coil 20, the magnetic flux φ ₃ generated by the coil 20 and the magnetic flux of the permanent magnet 29 are mixed inside the magnetic material 28. The flow direction with φ ₁ is the same direction from top to bottom, but since the inside of the magnetic material 28 is almost saturated with the magnetic flux of the permanent magnet 30, the magnetic flux generated by coil excitation flows into the magnetic material 28. It is almost impossible to pass inside.
On the other hand, the upper end 33a of the magnetic material 28 is the N pole,
When the lower end 33b becomes the S pole, the coil 20
The generated magnetic flux flows inside the magnetic material 28 from top to bottom. Until the coil 20 is energized,
The magnetic flux of the permanent magnet 30 was flowing from top to bottom in the magnetic material 28, but due to the magnetization, the magnetic resistance inside the magnetic material 28 increased, and the magnetic flux of the permanent magnet 30 was generated by the excitation coil. It follows the magnetic flux φ ₃ . That is, coil 2
When 0 is excited, most of the magnetic poles generated at the upper end 33a of the magnetic material 28 become N poles, and are opposite to the polarity N of the permanent magnet 31 on the yoke 22 side with the same polarity. As a result, a repulsive force acts between the upper end portion 33a of the magnetic material 28 and the magnetic pole portion 23a of the yoke 22,
At the same time, the upper ends 33a, 34 of both magnetic materials 28, 29
The armature 24 rotates to the right in FIG. 1 due to an attractive force acting between the armature a and the other magnetic pole portion 23b of the yoke 22.

6 and 7 show a state in which the upper ends 33a and 34a of both magnetic materials 28 and 29 are attracted and attracted to the magnetic pole portion 23b of the yoke 22. FIG. In addition, FIG. 8 shows the excitation current I in that case, the magnetic fluxes φ ₄ and φ ₅ passing through the armature 24, and the attractive force F ₄ and
The waveform with _F5 is shown. In the states shown in FIGS. 6 and 7, when the upper ends 33a and 34a of the magnetic materials 28 and 29 are N poles and the lower ends 33b and 34b are S poles, the magnetic material 28 with the permanent magnet 30 and the yoke In the magnetic circuit 35 that passes between the magnetic material 28 and the magnetic material 28, as described above, the magnetic flux φ ₃ generated by the coil 20
, the magnetic resistance inside the magnetic material 28 increases, and the magnetic flux φ ₁ of the permanent magnet 31 follows the magnetic circuit 35 passing through the magnetic material 28, causing the magnetic material 28 and the yoke 22 The magnetic flux φ ₄ flowing between them is the magnetic flux φ ₃ generated by the excitation of the coil 20.
and the magnetic flux φ ₁ generated by the permanent magnet 30.

Next, in the opposite case to the above state, that is, magnetic material 2
When the upper ends 33a and 34a of 8 and 29 are S poles and the lower ends 33b and 34b are N poles, the magnetic flux φ ₃ generated by the coil 20 and the magnetic flux φ ₁ of the permanent magnet 30 flow inside the magnetic material 28. Since the directions are the same from top to bottom, almost no magnetic flux φ ₃ generated by coil excitation can pass through the inside of the magnetic material 28 .

On the other hand, as shown in FIG. 8, the magnetic flux φ ₅ flowing between the other magnetic material 29 and the yoke 22 shows a general alternating current magnetic flux waveform, and has the same frequency as the excitation current waveform. As a result, as shown in FIG. 8, the attractive force F ₅ generated by the magnetic flux φ ₅ passing through one of the magnetic materials 29 is:
The frequency is twice the attractive force F ₄ generated by the magnetic flux φ ₄ passing through the other magnetic material 28, and when F ₅ is zero,
F ₄ is not zero, and conversely, when F ₄ is zero,
_F5 is maximized, and the amateur 24 is sucked and held by the yoke 22 without groaning. In the non-excited state, the magnetic flux φ ₁ of the permanent magnet 30 immediately follows a loop passing through the inside of the magnetic material 28, so
There is no attractive force between the upper end 33a of the yoke 22 and the magnetic pole part 23b of the yoke 22, and the armature 24 is rotated to the left by the magnetic force of the permanent magnet 31 on the yoke 22 side, returning to the state shown in FIG. . In this way, the armature 24 is returned to its original state by the magnetic force of the permanent magnet 31, so power consumption is reduced.

As can be seen from the above description, according to the present invention, an alternating current electromagnet that eliminates the need for a dark coil and a diode, prevents the generation of hum, suppresses heat generation, and realizes cost reduction, as well as reduces power consumption. can be provided.

[Brief explanation of the drawing]

Fig. 1 is a front view of an AC electromagnet according to an embodiment of the present invention, Fig. 2 is a plan view of the electromagnet, Fig. 3 is a sectional view taken along line 3-3 in Fig. 1, and Fig. 4 is a perspective view of the armature. , Figures 5 to 7 are operation explanatory diagrams, and Figure 8
The figure is a waveform diagram of exciting current, magnetic flux, and attractive force. Figure 9 is a partially cutaway side view of a conventional AC electromagnet. Figure 10 is a waveform diagram of its exciting current and magnetic flux. Figure 11 is a waveform diagram of another conventional AC electromagnet. FIG. 12, a partially cutaway side view of the AC electromagnet, is a waveform diagram of its exciting current and magnetic flux. 20... Excitation coil, 22... Yoke, 23
a, 23b...Magnetic pole part, 24...Amateur, 2
5...Hollow part, 26...Hinge part, 28, 29...
...Magnetic material, 30, 31...Permanent magnet, 32...Magnetic circuit.

Claims (1)

[Claims] 1 comprising an excitation coil, a yoke having a pair of opposing magnetic pole parts and arranged to surround the excitation coil, and an armature hingedly supported by the yoke within a hollow part of the excitation coil; The above amateurs are magnetically isolated from each other,
and a pair of magnetic materials that are mechanically coupled and attracted to one magnetic pole portion of the yoke, and a permanent magnet provided on one of the magnetic materials, and at least the magnetic material on the permanent magnet side of the armature is attached to the above-mentioned magnetic material. A return permanent magnet to be attracted to the other magnetic pole part of the yoke is placed in the magnetic circuit between the other magnetic pole part of the yoke and the hinge part, and is placed along this magnetic circuit with the same polarity as the permanent magnet on the armature side. An alternating current electromagnet characterized by being interposed so as to face each other.