JPS58186912A - Electro-magnet apparatus - Google Patents

Abstract

PURPOSE:To reduce a cost through application of a low cost permanent magnet and to carry out fine adjustment of attracting force by respectively arranging the edge of armature where coil is provided at the gap formed at the edge of both yokes and by reducing magnetism of permanent magnet of Alnico system. CONSTITUTION:A is a cheap permanent magnet such as a ferrite magnet, while B is an expensive permanent magnet such as Alnico magnet which can easily be reduced in magnetism. Both permanent magnets are arranged in parallel so that the N and S poles are set in the same direction. The linear first yoke 1 is set in contact with the one end while the U-shaped second yoke 2 with the other end, and the edge of U-shaped armature 3 is movably set in the gap between the edges of both yokes. 4 is an excitation coil. Even when reverse field is applied to permanent magnets with the straight line L considered as operating point, both magnets are not reduced in magnetism even after the reverse field is eliminated. However, when a reverse field is applied with the straight line M considered as the operating point, since a reverse field is applied in such a manner that the straight line M exceeds the bonding point of the curve B, a value of magnetic flux density of permanent magnet B is reduced to BB'.

Description

[Detailed description of the invention] The present invention relates to a polarized electromagnet device.

Conventionally, for polarized electromagnets that need to be demagnetized, permanent magnets such as alnico-based magnets that are easy to demagnetize have been used, but alnico-based permanent magnets are expensive, so they have a big disadvantage in terms of cost. There were drawbacks. In addition, in polarized electromagnets using permanent magnets, due to variations in magnetomotive force of the permanent magnets and variations in permeance of the magnetic circuit, v
The attraction force of the a-electromagnet is not stable, and for this reason, the performance of relays and renoids using polar electromagnets cannot be obtained.

The present invention aims to improve the above-mentioned drawbacks, reduce costs by using inexpensive permanent magnets, and provide an electromagnet device that can use fine p4 adjustment of the attractive force.

Next, embodiments of the present invention will be described with reference to the drawings.

The first diagram shows an embodiment of the present invention. In the diagram, M is an inexpensive permanent magnet such as a 7-piece light magnet, and B is an expensive but easily demagnetized permanent magnet such as an alnico magnet. Both permanent magnets are arranged parallel to each other so that N and S& are in the same direction, and furthermore, one end face has a linear first yoke 11 and the other end face has a U-shaped second yoke. The ends of the U-shaped armatures 3 are movably arranged in the gap between the ends of both yokes. Excitation coils from four companies are shown.

Next, a method for demagnetizing the permanent magnet used in this electromagnet device will be described.

FIG. 2 shows the demagnetization curves of ferrite permanent magnet B and alnico permanent magnet B. The demagnetization curve of permanent magnet B is
It has a gentle slope compared to , and the value of magnetic flux density is smaller than that of alnico permanent magnet. Even if a reverse magnetic field is applied to the permanent magnet so that the operating point is straight, if the opposite magnetic field is removed, both permanent magnets will not be demagnetized.

But straight! ! When a reverse magnetic field is applied so that y is the operating point, the M straight line passes through the bending point of curve B and the reverse magnetic field is applied, so the value of magnetic flux density for permanent magnet BK is - in the figure. It is demagnetized.

As a result, the magnetic flux densities of the permanent magnets BA and B become B and -', and two permanent magnets, BA and SA, are used.

Figure 3 shows the relationship between the stroke and the suction force. In Figure 1, the armature is moved at both ends by 1°2.
．． The relationship between the attraction force and the stroke can be determined by the degree of demagnetization of the alnico thread permanent magnet explained earlier in 1.1. According to the present invention, the attraction force can be finely adjusted compared to the case where only permanent magnet B is used for demagnetization as shown in Fig. 3. can be done. Furthermore, since the permanent magnet B is more expensive than the permanent magnet M, a structure composed of only the permanent magnet B also has the effect of being able to be manufactured at a low cost as a whole.

In the above embodiments, alnico permanent magnets and ferrite permanent magnets have been described, but it is needless to say that other permanent magnets having the above-mentioned properties can be similarly implemented.

[Brief explanation of drawings]

Fig. M1 shows the electromagnet device of the present invention, Fig. 2 shows demagnetization curves of alnico permanent magnets and ferrite permanent magnets, and Fig. 3 shows stroke and attraction force characteristics. A, B...Permanent magnet, 1.2...Yoke, 3...
Amateur, 4... Coil patent creator

Claims (1)

[Claims] Alnico permanent magnets and ferrite permanent magnets are mutually N,
Eight poles are arranged in parallel so that they have the same polarity, first and second yokes are brought into contact with the end faces of the permanent magnet, respectively, and an empty portion is formed by the ends of both the yokes. An electromagnet device characterized in that an armature arm provided with a coil is disposed at each end, and an alnico permanent magnet is demagnetized.