JPH0810945Y2 - Electromagnetic solenoid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an electromagnetic solenoid without a fixed iron core.

[Prior Art] In a conventional electromagnetic solenoid, a fixed iron core fixed to a predetermined portion of a yoke and fitted from one end into a hollow of an electromagnetic coil is provided, and a movable iron core having a tip portion facing the fixed iron core is provided. It is movably arranged in the hollow of the coil and configured so that the movable iron core is attracted to the fixed iron core by electromagnetic force, and the attracting surfaces of the fixed iron core and the movable iron core are formed into a flat surface or a conical surface.

Further, as shown in FIG. 3, a movable iron core 12 is arranged in the hollow of the electromagnetic coil 11, and a yoke 13 which is externally mounted on the electromagnetic coil 11 is provided.
It has been proposed that the portion of the movable iron core 12 facing the tip of the movable iron core 12 is bent so as to project to the outside, and the tip of the movable iron core is inserted into the inside of the protruding portion 14 (Actual Kosho).
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[Problems to be solved by the invention] However, in the case where the yoke is provided with the fixed iron core, the stroke of the movable iron core cannot be increased, and not only a large attracting force cannot be obtained. It takes a lot of man-hours to install and the production is troublesome. In addition, when a part of the yoke is projected to the outside, there is an advantage that it is not necessary to provide a fixed iron core, but the structure of the yoke itself becomes complicated, and there is a disadvantage that the yoke drawing process is required and the number of steps is increased. Therefore, as shown in the attraction force characteristic curve of FIG. 2B, a large attraction force was not obtained at the target stroke value.

In consideration of such a point, the present invention eliminates the fixed iron core, and is capable of obtaining a large suction force with a simple structure.

[Means for Solving the Problem] Therefore, a small-diameter portion is provided at the tip of the movable iron core, and a hole for inserting the small-diameter portion by the movement of the movable iron core is provided at a position facing the tip of the movable iron core of the yoke. ing.

[Operation] Therefore, when the movable iron core is not sucked,
The gap between the small diameter portion at the tip and the yoke is kept small, reducing the magnetic resistance due to the operation of the electromagnetic coil, and when the small diameter portion is inserted into the hole of the yoke by suction, suction is performed according to the shape and size of the small diameter portion. The force becomes almost constant, and the stepped portion of the movable iron core is attracted to the inner surface of the yoke to generate a large attraction force.

[Embodiment] An embodiment shown in this figure will be described.

Reference numeral 1 denotes an electromagnetic coil wound around a winding frame 2, in which a movable iron core 4 is arranged in a hollow portion 3 of the winding frame 2 so as to be movable in the axial direction. 5 is a small-diameter portion provided at the tip of the movable iron core 4, 6 is a step portion for providing the small-diameter portion, 7 is a U-shaped yoke that is mounted on the electromagnetic coil 1, and is located at a position facing the small-diameter portion 5 of the movable iron core 4. A hole 8 into which the small diameter portion 5 is inserted is provided. 9 is a movable iron core 4
This is a hole for inserting.

When the electromagnetic coil 1 is not operating, the tip of the movable iron core 4 is separated from the yoke 7, and the tip of the small diameter portion 5 and the yoke 7 are separated.
The holes 8 of the above are held in a state of being close to each other or slightly inserted.

When the electromagnetic coil 1 is energized, the movable iron core 4 is sucked and moved through the small diameter portion 5 close to the yoke, and the small diameter portion 5 of the movable iron core is inserted into the hole 8. Therefore, after the magnetic resistance is rapidly reduced at the beginning of the suction, the change in the magnetic resistance is reduced, and as shown by the characteristic curve a in FIG. 2, the suction force is largely changed and then becomes almost constant. The inner surface of the yoke 7 is attracted and abutted to generate a large suction force.

[Effects of the Invention] As described above, according to the present invention, the small-diameter portion is provided at the tip of the movable core that is movably arranged in the hollow of the coil, and the small-diameter portion is provided by the movement of the movable core at a position facing the movable core tip of the yoke. Since the hole for inserting the magnet is provided, the tip of the small diameter part of the movable iron core and the yoke are close to each other, so that the movable iron core can be smoothly moved by the suction action of the electromagnetic coil, and reliable operation can be obtained, and the stroke can be increased. In addition, there is no need to attach a fixed iron core as a separate component, the shape of the yoke can remain flat, processing and assembly are extremely easy, inexpensive and suitable for mass production, uniform suction characteristics are obtained, and quality is stable. There is an effect that can be made.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 is a suction force characteristic curve diagram, and FIG. 3 is a side sectional view showing a conventional example. 1 is an electromagnetic coil, 2 is a winding frame, 3 is a hollow part, 4 is a movable iron core, 5 is a small diameter part, 6 is a step part, 7 is a yoke, and 8 is a hole.

Claims (1)

[Scope of utility model registration request] 1. A hollow electromagnetic coil, a yoke mounted on the electromagnetic coil, and a movable iron core movably arranged in the hollow and having a small diameter portion at its tip, and opposed to the movable iron core tip of the yoke. An electromagnetic solenoid characterized in that a hole for inserting a small-diameter portion by the movement of the movable iron core is provided at a position to be moved.