JPH01286301A - Electromagnet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to electromagnets used in solenoid valves for gas appliances and the like.

[Prior Art] Conventionally, an electromagnet used in a solenoid valve for gas appliances, etc. has a yoke 1 and a yoke 1, as shown in FIG. 5 or 6.
A fixed iron core 2 fixed to the fixed iron core 2, a movable iron core 3 displaceably provided with respect to the fixed iron core 2, and a spring 4 that urges the movable iron core 2 in the direction of arrow 6 so as to be separated from the fixed iron core 2.
is wound around a magnetic path consisting of the yoke l, the fixed iron core 2i3, and the movable iron core 3 via a pobbin 7, and is energized to fix the movable iron core 3 against the biasing force of the spring 4 in the direction of the arrow 6. It consists of an electric winding 5 that is attracted to the iron core 2.

When the fixed iron core 2 and the movable iron core 3 are separated from each other as shown in FIG. 5 or 6, the electric winding 5 is energized and the movable iron core 3 is attracted to the fixed iron core 2 by the action of the induced magnetic flux 8. .

After that, when the applied current is gradually decreased to a predetermined current or less, the magnetic attraction force due to the magnetic flux 8 is
The biasing force in the direction is overcome, the fixed iron core 2 and the movable iron core 3 are released from the adhesion state, and the movable iron core 3 is released and separated from the fixed iron core 2, returning to the state shown in FIG. 5 or 6.

[Problem to be solved by the invention j However, in the conventional device described above, the spring 4 shown in FIG. Therefore, there was a risk that the movable iron core 3 would be displaced in the axial cross-sectional direction due to the special electric current of the suction operation, rotate around the axis, and be attracted to the fixed iron core 2.

For this reason, the attraction surfaces of the fixed core and the movable core are displaced each time the attraction operation is performed, and the magnetic resistance of this portion changes, resulting in the minimum retained ampere-turn after the attraction of the movable core 3 to the fixed core 2,
In other words, the maximum released ampere-turns could vary significantly.

In particular, for high-sensitivity electromagnets, even if a core material with low coercive force is used for the reasons mentioned above, the residual magnetic flux of the core material will cause attraction between the fixed core and the movable core, as well as differences in attraction surface dimensions, surface roughness, etc. There were cases where the movable core was not reliably separated from the fixed core even if the current was gradually reduced to a predetermined value or less.

For this reason, for example, in solenoid valves for gas appliances, there is a problem that the reliability of the so-called fail-safe function, which automatically closes the solenoid valve in the event of an accident in the power supply or solenoid valve control circuit, etc., is significantly impaired. There was a point.

SUMMARY OF THE INVENTION 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 in which a movable core is reliably opened and separated from a fixed core at a predetermined attraction/holding current or less.

[Means for Solving the Problems 1] The present invention includes a yoke, a fixed core fixed to the yoke, a movable core displaceable with respect to the fixed core, and a movable core arranged so as to be separated from the fixed core. The movable core is wound around a magnetic path consisting of a spring that biases the yoke, a fixed core, and a movable core, and is energized to cause the movable core to contact the fixed core against the biasing force of the spring. This electromagnet is an improved electromagnet consisting of an electric winding to be attracted, and is characterized in that one end of the spring is fixed to the movable iron core, and the other end is fixed to the fixed iron core or yoke.

[Function] According to the present invention, one end of the spring is fixed to the movable core, and the other end is fixed to the movable core or the yoke. Rotation is prevented.

Therefore, the adsorption state of the fixed iron to the movable iron core is stabilized, the influence of fluctuations in residual magnetic flux due to hysteresis of the iron core material is eliminated, and the movable iron core is reliably opened and separated from the fixed iron core at a predetermined current or less.

〔Example〕

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

FIG. 1 is a sectional view of a first embodiment of the invention.

This embodiment has the same configuration as the conventional device shown in FIG. 5, but differs in the following points.

One end 4 of the spring 4a shown in FIGS. 3(a) and 3(b)
d is fitted into the hole 3a of the movable iron core 3, and the other end 4c is fitted and fixed into the hole 1b of the yoke 1a.

FIG. 2 is a sectional view of a second embodiment of the invention.

This embodiment has the same structure as the conventional device shown in FIG. 6, but differs in the following points.

One end 4 of the spring 4a shown in FIGS. 3(a) and 3(b)
d was fitted into the hole 3b of the movable iron core 3, and the other end 4c was fitted into the hole 2a of the fixed iron core 2 and fixed.

In the above embodiment, a spring 4b having one end 14f and the other end 4g protruding in the axial cross-sectional direction may be used, as shown in FIGS. 4(a), 4(b), and 4(c).

[Effect of the Invention 1] As explained above, the present invention stabilizes the adsorption state of the fixed iron core to the movable iron core, and the movable iron core is reliably opened and separated from the fixed iron core at a predetermined current or less. This has the effect of significantly increasing the reliability of the so-called fail-safe function, which automatically closes the solenoid valve in the event of an accident with the power supply or the solenoid valve control circuit.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the first embodiment of the present invention, Fig. 2 is a sectional view of the second embodiment of the invention, and Figs.
4(a), (b), and (C) are explanatory views of other springs. FIG. 5 is a sectional view of the conventional device. 7(a) and 7(b), which are sectional views of other conventional devices, are explanatory diagrams of springs constituting the conventional devices of FIGS. 5 and 6. 1...-Yoke 2...Fixed core 3...-Movable core 4a, 4b...Spring 5...-Electric winding applicant Mic Kogyo Co., Ltd.

Claims (1)

[Scope of Claims] A yoke, a fixed core fixed to the yoke, a movable core displaceable with respect to the fixed core, and a movable core that is biased away from the fixed core. A spring, and an electric winding that is wound around a magnetic path consisting of the yoke, a fixed iron core, and a movable iron core, and is energized to attract the movable iron core to the fixed iron core against the biasing force of the spring. An electromagnet comprising the following: One end of the spring is fixed to the movable iron core, and the other end of the spring is fixed to the fixed iron core or the yoke.