JPH0241846Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The invention uses permanent magnets in movable members such that at least one side faces the other, and the distance between these members is a certain distance. This relates to a magnetic circuit configured to attract at the following times and repel at a certain distance or more.

[Prior art]

Conventionally, this type of magnetic circuit had the disadvantage that two magnetic circuits were required for attraction and repulsion, making the device large and heavy, and requiring time and effort to assemble. .

[Purpose of invention]

The purpose of the present invention is to provide a magnetic circuit that is small and lightweight and can reduce the number of work steps by having both attraction and repulsion functions in one magnetic circuit.

[Structure of the idea]

The magnetic circuit according to the present invention is provided in movable members such that at least one side faces the other, the magnetization direction being perpendicular to the opposing surface on the opposing surface side of the one member. a first permanent magnet is arranged so that the second permanent magnet faces the opposite surface of the other member, and a second permanent magnet is arranged so that the same polarity as the first permanent magnet faces,
and a magnetic yoke is brought into contact with the opposing surface of the second permanent magnet and the first permanent magnet.
It is characterized by having both attraction and repulsion effects depending on the distance between the permanent magnet and the magnetic yoke.

[Principle and operation of the invention]

Next, the principle and operation of the present invention will be explained with reference to the drawings.

Referring to FIG. 1, only the basic magnetic circuit of the present invention is shown with members omitted, and first and second permanent magnets are connected via a magnetic yoke 3 so that the magnetization directions M are opposite to each other. 1 and 2 are arranged so that the poles of the opposing surfaces 1a and 2a are the same (1a and 2a are N poles or S poles), and the magnetic yoke 3
is brought into contact with the second permanent magnet 2, and the magnetic yoke 3 and the first permanent magnet 1 have a distance a. According to this structure, when the distance a is less than a certain distance a ₀ , the first permanent magnet 1 and the magnetic yoke 3 exhibit an adsorption effect, and when the distance a is more than a certain distance a ₀ , the first permanent magnet The magnetic yoke 3 exhibits a repulsive effect. Next, with reference to FIG. 2, the function and operating principle of the magnetic circuit according to the present invention will be explained.

Referring to FIG. 2, an example is shown in which the opposing surfaces 1a and 2a of the first and second permanent magnets 1 and 2 are N poles, and FIG. When the distance a from the permanent magnet 1 to the permanent magnet 1 is a ₁ longer than the above certain distance a ₀ (a ₁ > a ₀ ), Fig. 2 b shows a certain distance.
An example is shown in which a ₂ is shorter than a ₀ (a ₂ < a ₀ ).

In FIG. 2a, the magnetic yoke 3 is magnetically induced by the second permanent magnet 2, so that the surface 3a facing the facing surface 2a of the second permanent magnet 2 is the S pole, and the facing surface of the first permanent magnet 1 is the S pole. The surface 3b facing 1a is magnetized to the north pole. Therefore, as shown in the figure, the lines of magnetic force 4 collide with each other and exhibit a repulsive effect.

On the other hand, in FIG. 2b, similar to FIG. 2a, the surface 3a of the magnetic yoke 3 facing the second permanent magnet 2 is magnetized to the S pole due to magnetic induction by the second permanent magnet 2. Since the distance a between the magnetic yoke 3 and the first permanent magnet 1 is short a ₂ (a ₂ <a ₀ ), the surface 3b of the magnetic yoke 3 facing the first permanent magnet 1 is also It is magnetized to the S pole by magnetic induction by the magnet 1, and as a result, the lines of magnetic force 4 enter the magnetic yoke 3, as shown in the figure, and exhibit an attraction effect.

Figure 3 is a diagram showing the relationship between the distance a between the magnetic yoke 3 and the first permanent magnet 1, and the strength of attraction and repulsion forces; when the distance a is greater than or equal to _{0, the repulsion force is greater, and when the distance a is less than or equal to a 0 ,} the attraction force is greater. It represents the action of force.

[Example of idea]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 shows a cross-sectional view of an embodiment of only the magnetic circuit according to the present invention, in which rare earth cobalt magnets are used for the first and second permanent magnets 1 and 2, and the opposing surfaces 1a, The pole of 2a is the N pole, and the first and second permanent magnets 1 and 2 and the magnetic yoke 3 have a ring shape with the same inner diameter and outer diameter, and the outer diameter φd ₁ = φ20 mm and the inner diameter φd ₂ = φ10mm and the first
The thickness w 1 and _{w 2} of the second permanent magnets 1 and ₂ are 4 mm.
It is. In a magnetic circuit having such a structure, the present inventor investigated the attraction and repulsion effects by varying the distance a between the magnetic yoke 3 and the first permanent magnet 1, and found that when the distance a was 0.35 mm or less It was confirmed that it exhibits an adsorption effect, and above that it exhibits a repulsion effect.

FIG. 5 is a diagram showing an application example of the magnetic circuit according to the present invention, in which a first permanent magnet 1 is disposed on one (moving) member 5 of the members that open and close the door, and the other (fixed) member 6 An example in which a second permanent magnet 2 and a magnetic yoke 3 are arranged is shown.

The application of the magnetic circuit according to the present invention is not only for opening and closing doors, but also for tick boxes, desk drawers, etc.
Needless to say, it can be applied to various things.

[Effect of idea]

As mentioned above, the magnetic circuit according to the present invention has 1
Since it combines the functions of both attraction and repulsion with a single magnetic circuit, the device can be made smaller and lighter, the number of assembly steps can be greatly improved, it is economical, and its application fields are wide-ranging.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the basic magnetic circuit of the present invention, Fig. 2 is a diagram for explaining the operating principle of the magnetic circuit, and Fig. 3 is a diagram showing the distance between the magnetic yoke and the first permanent magnet. A diagram showing the relationship between the strength of attractive force and repulsive force, FIG. 4 is a sectional view showing the structure of an embodiment of the magnetic circuit according to the present invention, and FIG. 5 shows an example of the application of the magnetic circuit according to the present invention. FIG. 1, 2...Permanent magnet, 3...Magnetic yoke.

Claims (1)

[Scope of utility model registration request] In a magnetic circuit provided in a movable member such that at least one of the members faces the other, a first permanent magnet is provided on the opposing surface side of the one member such that the direction of magnetization is perpendicular to the opposing surface. A magnet is disposed on the opposing surface side of the other member,
a second permanent magnet so that the same polarity as the first permanent magnet is opposite to the first permanent magnet;
1. A magnetic circuit comprising: a permanent magnet, and a magnetic yoke is brought into contact with a surface facing the first permanent magnet and the second permanent magnet.