JPH0381288B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnet that energizes an electric winding to generate a mechanical attractive force so that a movable core moves toward and away from a fixed core.

[Conventional technology]

Conventionally, an electromagnet that generates a mechanical attraction force by energizing an electric winding so that a movable core moves toward and away from a fixed core is shown in FIG. 7 and FIG. 6, which is a partial configuration diagram of FIG. 7, for example. As shown, a columnar fixed core 1, a yoke 2 to which the fixed core 1 is fixed, and a columnar movable core 6 whose magnetic pole surface 5 approaches and separates from the magnetic pole surface 3 of the fixed core 1 through a gap 4. and fixed core 1,
It consists of a magnetic path formed by the yoke 2, the movable iron core 6, and the gap 4, an electric winding 8 that excites this magnetic path by being energized, and a spring 12 connected to the movable iron core 6. One of the magnetic pole surfaces 3 of 1 and the magnetic pole surface 5 of the movable iron core 6 is formed into a substantially truncated conical recess 9, and the other magnetic pole surface is formed into a recess 9.
The convex portion 10 is formed into a substantially truncated conical shape that approximately fits into the convex portion 10.

It is almost impossible to perform a rigorous analytical approach to the design and manufacture of electromagnets that generate the required stroke and attraction force with a given power, and conventionally, the so-called index is calculated by dividing the parallel root of the required attraction force by the stroke length. The void density was assumed based on the number of voids, and design and manufacturing were carried out based on accumulated empirical values.

[Problem that the invention seeks to solve]

For this reason, the above-mentioned conventional device suffers from the presence of leakage magnetic flux.
There was a problem in that the attractive force characteristics were not always good due to saturation development of the magnetic material.

Therefore, the present invention was proposed in order to solve the above-mentioned problems, and an object of the present invention is to provide an electromagnet with good attractive force characteristics.

[Means for solving problems]

The present inventor studied the conventional devices shown in FIGS. 6 and 7.

Here, the attractive force F between the fixed iron core 1 and the movable iron core 6 acts in the direction of arrow 11 due to the excitation of the magnetic path,
As is well known, its size is expressed by the following equation.

F=(μπr _a h/x ² sinα・cosα) U ² _... (1) where, ; Side surface 10a of convex portion 10 and column axis 6 of movable iron core 6
Angle between a and the orthogonal plane 6b Now, regarding 1/(sinα・cosα) on the right side of equation (1), if you perform numerical calculations for angles of α of 40° or more, the results are shown in the graph of Figure 8. get.

It is clear from FIG. 8 that the suction force increases significantly when α is greater than or equal to 70 degrees and less than 90 degrees.

Next, a plunger electromagnet according to the present invention shown in FIG. 3rd when measured at 3.0mm
As shown in the figure, the height h of the convex part 10 is adjusted to the movable distance of the movable core 6 so that the convex part 10 is slightly inserted into the concave part 9 when the movable core 6 is farthest from the fixed core 1. x = 3.2 slightly higher than 3.0mm
The suction force increased by approximately 25% in mm.

The present invention was established based on the above-mentioned knowledge, and includes a columnar fixed core, a yoke to which the fixed core is fixed, and a magnetic pole surface that approaches and separates from the magnetic pole surface of the fixed core through a gap. It consists of a columnar movable core, a magnetic path formed by the fixed core, a yoke, a movable core, and a gap, and an electric winding that excites the magnetic path when energized. and an improved electromagnet in which one of the magnetic pole surfaces of the movable iron core is formed into a substantially truncated conical concave portion, and the other magnetic pole surface is formed into a substantially truncated conical convex portion that approximately fits into the concave portion. and an inclination angle α between the side surface of the convex portion and a plane perpendicular to the column axis of the movable iron core is formed to be 70 degrees or more and 90 degrees or less, and when the movable iron core is farthest from the fixed iron core, This electromagnet is characterized in that the height h of the convex portion is formed so that the convex portion is slightly inserted into the concave portion.

[Effect]

According to the present invention, since the inclination angle α between the side surface of the convex portion and the plane orthogonal to the column axis of the movable iron core is formed to be 70 degrees or more and 90 degrees or less, the suction force is increased by the above equation (1), and the movable iron core is movable. Since the height h of the protrusion is formed so that the protrusion is slightly inserted into the recess when the iron core is farthest apart from the fixed iron core, the suction force is further increased.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments with reference to the drawings.

FIG. 1 is a partial cross-sectional view of one embodiment of the present invention. Although the configuration is common to the conventional device shown in FIG. 6, it differs in the following points.

Side surface 10a of convex portion 10 and column shaft 6a of movable iron core 6
The inclination angle α with respect to the plane 6b orthogonal to the plane 6b is formed to be 70 degrees or more and 90 degrees or less.

Although the air vent portion 13 is provided, it may not be provided.

Furthermore, the height h of the convex portion 10 is formed so that the convex portion 10 is slightly inserted into the concave portion 9 when the movable iron core 6 is farthest apart from the fixed iron core 1.

That is, in this embodiment, the height h of the convex portion 10 is made slightly higher than the movable distance x of the movable iron core 6.

In addition, the dotted line illustration shows the adsorption state of the fixed iron core 1 and the movable iron core 6 when x=0.

In the second embodiment shown in FIG. 2, the tip of the convex portion 10 and the concave portion 9 are configured to be in direct contact with each other.

In the embodiments shown in FIGS. 4 and 5, the inclination angle α is 90
It was configured once.

Note that it is preferable that the fixed core 1 and the movable core 6 be formed in a cylindrical shape, but they may be formed in a cylindrical shape.
It is preferable that both the recess 9 and the convex part 10 have a truncated cone shape, but they do not need to be strictly truncated cones, and may be formed approximately in the shape of a truncated cone.

〔Effect of the invention〕

As explained above, the present invention has the effect of increasing the suction force, particularly the initial suction force of the stroke.

[Brief explanation of drawings]

FIG. 1 is a partial configuration diagram of the first embodiment of the present invention,
FIG. 2 is a partial configuration diagram of the second embodiment of the present invention, FIG. 3 is a suction force characteristic graph of the embodiment of FIG. 1, and FIG.
Figure 5 is a partial configuration diagram of the third embodiment of the present invention, Figure 5 is a partial configuration diagram of the fourth embodiment of the invention, Figure 6 is a partial explanatory diagram of a conventional device, and Figure 7 is the same as in Figure 6. FIG. 8 is a block diagram of the conventional device, and is a graph of the suction force characteristics of the conventional device shown in FIG. DESCRIPTION OF SYMBOLS 1... Fixed iron core, 2... Yoke, 3, 5... Magnetic pole surface, 4... Gap, 6... Movable core, 8... Electric winding, 9... Concave part, 10... Convex part, 10a ……side.

Claims (1)

[Scope of Claims] 1. A columnar fixed core, a yoke to which the fixed core is fixed, a columnar movable core whose magnetic pole surface approaches and separates from the magnetic pole surface of the fixed core through a gap, and a yoke to which the fixed core is fixed. It consists of a magnetic path formed by a fixed iron core, a yoke, a movable iron core, and a gap, and an electric winding that excites the magnetic path when energized. In an electromagnet in which one of the magnetic pole surfaces is formed in a substantially truncated conical recess and the other magnetic pole surface is formed in a substantially truncated conical recess that approximately fits into the recess, the side surface of the convex portion and the movable iron core. An inclination angle α with a plane orthogonal to the column axis is formed to be 70 degrees or more and 90 degrees or less, so that the convex portion is slightly inserted into the concave portion when the movable core is farthest from the fixed core. An electromagnet characterized in that the convex portion has a height h.