JPH03196505A - Monostable electromagnet - Google Patents

Abstract

PURPOSE:To apply a monostable electromagnet to deviated spring load without requiring a working spring by fixing one magnetic pole of a permanent magnet approximately parallel with the direction of movement of an armature and installing a magnetic pole plate oppositely faced to the other magnetic pole to another side of the yoke. CONSTITUTION:Permanent magnets 4 are fixed at another end section 8 of a yoke l and arranged near a contacting and separating section 7, and magnetic pole plates 11 oppositely faced to the permanent magnets 4 are mounted to an armature 3. Consequently, magnetic flux PHI1 flows through the magnetic pole plates 11, the armature 3, the yoke 1 and an auxiliary yoke 9 by the magnetizing force of the permanent magnets 4, but force attracting the armature 3 in the return direction does not work approximately because a magnetic circuit is formed in loose coupling. When magnetic flux PHI2 is overlapped to magnetic flux PHI3 generated by exciting a coil 2, attraction force to the operation side of the armature 3 can be increased by magnetic flux PHI2, thus reducing the power consumption of the coil 2, then augmenting attraction force with approach to a magnetic pole N of the magnetic pole plates 21. Accordingly, a monostable electromagnet can be applied to deviated spring load without requiring a working spring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a monostable electromagnet that is applied to electromagnetic contactors, electromagnetic relays, etc. for switching on and off three-phase motors.

[Conventional technology]

Conventional monostable electromagnets of this type have generally been so-called non-polar electromagnets that do not include a permanent magnet in their magnetic circuits, such as clapper-type electromagnets. This non-polar type! Although magnets are low-cost, only the magnetic flux generated by the coil can be used to drive the armature, so it is necessary to increase power consumption in order to obtain a certain range of attractive force.

On the other hand, in recent years, polarized IT magnet devices in which a permanent magnet is included in the magnetic circuit have been proposed in order to reduce the power consumption of electromagnets (for example, Japanese Patent Publication No. 17333/1983, Japanese Utility Model Publication No. 58
-10327).

[Problem to be solved by the invention]

The monostable electromagnet disclosed in Japanese Patent Publication No. 62-17333 can use the magnetic flux of the permanent magnet for the driving force of the armature, so it can consume less power than the non-polar type when obtaining a certain range of attractive force. However, because of its bistable electromagnetic structure, it was unsuitable for uneven spring loads such as those used in electromagnetic contactors used on boats.

In addition, the monostable Nfi 1 stone of Utility Model Publication No. 58-10327 has characteristics intermediate between the non-polar type and the polar type conventional example, that is, it is polar, so it can achieve low power consumption, and unlike the conventional example, it is asymmetric. Because it is a magnetic circuit, it has characteristics suitable for uneven spring loads.

However, since the magnetic flux of the permanent magnet flows in a closed loop on the return side of the armature, the force in the return direction becomes extremely large, and therefore an operating spring is required to bias the armature toward the operating side in alignment with the spring load. It had drawbacks such as:

It is therefore an object of the present invention to provide a polarized monostable electromagnet that can be applied with a biased spring load without the need for actuation springs.

[Means to solve the problem]

This invention is monostable! The magnet includes a yoke, an armature having a connecting/separating part that can be connected to and connected to the yoke, and a coil that is wound around at least one of the yoke and the armature and attracts the armature to the yoke by excitation.

In a monostable electromagnet comprising a permanent magnet disposed near a contact/separation portion of the armature and whose magnetization direction is substantially parallel to the moving direction of the armature, one magnetic pole of the permanent magnet is connected to the yoke and the armature. It is characterized in that a magnetic pole plate fixed to one side and facing the magnetic winding of the other is provided on the other of the yoke and the armature.

[Effect]

According to the monostable electromagnet of the present invention, when the coil is excited, the contact/separation portion of the armature operates so as to be attracted to the yoke. In this case, the magnetic flux generated by the excitation of the coil can form a closed magnetic path by the yoke and armature without including a permanent magnet. Furthermore, the magnetic flux generated by the permanent magnet can be superimposed on the magnetic flux generated by the coil, and since an attractive force acts between the permanent magnet and the magnetic pole plate, the attractive force of the armature can be increased, and power consumption can therefore be reduced. On the other hand, in the return position 1 of the armature, the magnetic flux of the permanent magnet does not form a closed loop.
Since the magnetic flux of the permanent magnet hardly acts in the return direction of the armature, it can be applied to a biased spring load without requiring a conventional operating spring, and an attractive force characteristic that easily matches the spring load can be obtained.

(Embodiment) A first embodiment of the present invention will be explained based on FIGS. 1 to 3. That is, this monostable electromagnet has a yoke
, a coil 2 , an armature 3 , and a permanent magnet 4 .

The yoke 1 is formed by bending a flat plate into a substantially U-shape.

The coil 2 is wound around one piece of the yoke l. The armature 3 has a pivot portion 5 that is magnetically coupled to the plate end surface of one end portion 6 of the yoke I, and also has a contact/separation portion 7 that approaches and separates from the plate end surface of the other end portion 8 of the yoke I by swinging. The contact/separation portion 7 is attracted to the yoke 1 by the excitation of the coil 2.

When not energized, it returns to the return position by a return spring (not shown) or the like. Note that a known hinge means is used as the pivot means for the one end portion 6 and the pivot portion 5.

The permanent magnet 4 is fixed to the other end 8 of the yoke 1 and
The armature 3 is provided with a magnetic pole plate facing the permanent magnet 4. That is, a pair of permanent magnets 4 are used as an example, and magnetic poles S are magnetically coupled and fixed to both ends of an auxiliary yoke 9, and a hole lO is formed in the center part, and the permanent magnets 4 are fitted to the other end 8 of the yoke 1. There is. Further, the magnetization direction of the permanent magnet 4 is approximately parallel to the moving direction of the contact/separation portion 7. Further, the magnetic pole plate 11 is integrally formed with the armature 3, and is bent into a double shape so that it comes into contact with or comes closest to the magnetic pole N, with the contact portion 7 in contact with the other end portion 8 of the yoke 1.

According to this embodiment, as shown in FIG. 3 (al), when the electromagnet is in the returned state, the magnetic flux Φ1 is transmitted by the magnetizing force of the permanent magnet 4 via the magnetic pole plate 11, the armature 3, the yoke 1, and the auxiliary yoke 9. However, since the magnetic circuit is loosely coupled, the force that attracts the armature 3 in the return direction hardly acts.

On the other hand, a part of the magnetic flux Φ2 is transmitted to the magnetic pole plate 11, the armature 3,
The magnetic flux Φ2 flows through the auxiliary yoke 9, but since the magnetic circuit is loosely coupled, the force that attracts the armature 3 in the return direction hardly acts;
A force is applied that attracts the to the operating side. Therefore, the force that attracts the armature 3 in the return direction is hardly applied, so
It can be applied to biased spring loads without requiring a conventional operating spring.

Next, when the coil 2 is energized, the armature 3 operates around the pivot portion 5 of the armature 3 so that the contact/separation portion 7 is attracted to the other end portion 8 of the yoke 1. As shown in FIG. 3 fbl, the magnetic flux Φ3 generated by the excitation of the coil 2 is configured to flow in the opposite direction to the aforementioned magnetic flux Φ.
Yoke 1 and armature 3 without permanent magnet 4
The magnetic flux Φ2 generated by the permanent magnet 4 and the magnetic flux Φ3 generated by excitation of the coil 2 flow through a closed magnetic path due to the magnetic flux Φ2 generated by the permanent magnet 4.
It will be superimposed on Therefore, as the magnetomotive force of the coil 2 increases, the attractive force generated between the yoke l and the armature 3 increases, and the magnetic flux Φ2 of the permanent magnet 4 can increase the attractive force toward the operating side of the armature 3.
Power consumption of the coil 2 can be reduced. Furthermore, as the magnetic pole plate 11 approaches the magnetic pole N, the attractive force of the magnetic pole plate 11 increases,
Contributes to the suction force of armature 3.

Furthermore, by attaching the permanent magnet 4 to the other end 8 of the yoke l, the magnetic flux obtained from the permanent magnet 4 increases, thereby increasing the attractive force, thereby further reducing power consumption.

Next, when the current t flowing through the coil 2 is cut off, the armature 3 returns to the state shown in FIG. 3 Fa+ by a return spring (not shown) or the like.

The yoke l was formed by bending one component into a substantially U-shape, but it can be formed by an L-shaped yoke and a rod-shaped or plate-shaped yoke
It may be formed into a substantially U-shaped bent shape by caulking or the like. Further, the auxiliary yoke 9 that contacts one pole of the permanent magnet 4 may be formed integrally with the yoke l instead of being a separate member. Furthermore, although the permanent magnet 4 is a pair in the above embodiment, it may be one.

Further, although the magnetic pole S of the permanent magnet 4 is magnetically coupled to the other end portion 8 of the yoke 1, the opposite magnetic pole N may be magnetically coupled.

Furthermore, although the permanent magnet 4 is directly fixed to the yoke 1, it may be fixed via a case that holds the yoke 1, a coil frame around which the coil 2 is wound, or the like (not shown). Also permanent magnet 4
may be a ferrite magnet, a rare earth magnet, or even a plastic magnet.Also, in the above embodiment, the magnetization direction of the permanent magnet 4 was completely parallel to the moving direction of the armature, but even if it is tilted by about 45 degrees, it is almost parallel. is within the range of Further, in the embodiment, the magnetic flux Φ3 flows in the opposite direction to the magnetic flux Φ1, but the magnetic flux Φ3 may flow in the same direction as the magnetic flux Φ1.

A second embodiment of the invention is shown in FIGS. 4 and 5.
That is, this monostable electromagnet is one in which a permanent magnet 4 is fixed to a contact/separation part 7 on the side of an armature 3, a lug 12 is integrally formed on the armature 3, and a permanent magnet 4 is attached to this lug 12. There is.

Further, a magnetic pole plate 11 is attached to the yoke 1. The rest is the same as the first embodiment.

By fixing the permanent magnet 4 to the armature 3 side, the weight of the movable part increases, but by manufacturing it by simultaneous molding with the armature 3, the number of parts can be reduced and assembly efficiency can be improved.

Note that a separate member may be used for the lug 12, and although the permanent magnet 4 is directly fixed to the armature 3,
It is also possible to use a separate member that operates at the same time.

In addition, in this invention, the coil 2 and the permanent magnet 4 may be provided in both the yoke l and the armature 3.

〔Effect of the invention〕

In the monostable electromagnet of the present invention, a permanent magnet whose magnetization direction is approximately parallel to the moving direction of the contact/separate part is arranged near the contact/separate part of the armature, and one magnetic pole of the permanent magnet is attached to one of the yoke and the armature. Since the magnetic pole plate that is fixed and faces the other magnetic pole is provided on the other of the yoke and the armature, the magnetic flux due to excitation of the coil can form a closed magnetic path by the yoke and the armature without including a permanent magnet. can. Furthermore, the magnetic flux generated by the permanent magnet can be superimposed on the magnetic flux generated by the coil, and since an attractive force acts between the permanent magnet and the magnetic pole plate, the attractive force of the armature can be increased, and power consumption can therefore be reduced. On the other hand, at the return position of the armature, the magnetic flux of the permanent magnet does not form a closed loop, and almost no magnetic flux of the permanent magnet acts in the direction of return of the armature. This has the effect of providing suction force characteristics that can be applied to loads and easily match spring loads.

[Brief explanation of drawings]

1 is a perspective view of the first embodiment of the present invention, FIG. 2 is an exploded perspective view thereof, FIG. 3 is an explanatory diagram of the operating state, FIG. 4 is a perspective view of the second embodiment, and FIG. The figure is an explanatory diagram of its operating state. DESCRIPTION OF SYMBOLS 1... Yoke, 2... Coil, 3... Armature, 4... Permanent magnet, 7... Contact/separation part, 11... Magnetic pole board diagram (b)

Claims (1)

[Claims] a yoke, an armature having a contact portion that can move toward and away from the yoke; a coil wound around at least one of the yoke and the armature to attract the armature to the yoke through excitation; In a monostable electromagnet comprising a permanent magnet disposed near a contact/separation part and having a magnetization direction substantially parallel to a moving direction of the armature, one magnetic pole of the permanent magnet is fixed to one of the yoke and the armature. A monostable electromagnet, characterized in that a magnetic pole plate facing the other magnetic pole is provided on the other of the yoke and the armature.