JPH0328043B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a self-holding solenoid activated by instantaneous energization.

BACKGROUND ART A conventional self-holding solenoid of this type has a fixed yoke 2 on the outside of an electromagnetic coil 1, as shown in FIG.
A movable core 3 is slidably provided inside the electromagnetic coil 1, and a permanent magnet 5 is installed so that the movable core 3 is self-adsorbed and held in a state in which it is in contact with the fixed core 4.
are fixed opposite to each other at symmetrical positions inside the fixed yoke 2, and when an instantaneous current is applied to the electromagnetic coil 1 so that a magnetic flux is generated in the opposite direction to the direction of the magnetic flux of the permanent magnet 5, the permanent magnet 5 The force holding the movable core 3 on the fixed yoke 2 decreased, and the force of the spring 6 caused the movable core 3 to separate from the fixed yoke 2. (For example, Japanese Utility Model Publication No. 59-23369) Problems to be Solved by the Invention However, in the above configuration, since the amount of magnetic flux of the opposing permanent magnets 5 is almost equal on the left and right sides, the seventh
As shown in the figure and FIG. 8, when the movable core 3 and the fixed core 4 are in contact with each other and are in an adsorbed and held state, the force with which the movable core 3 is attracted by the left and right permanent magnets 5 is almost the same, and the movable core 3 is pulled in the lateral direction. The direction of inclination is not constant.
Therefore, the contact points between the movable core 3 and the fixed core 4 are also not constant. The problem is that the contact point between the movable core 3 and the fixed core 4, that is, the state of the attraction surface, is not constant, so the attraction and holding force is not constant, and the current that flows through the electromagnetic coil 1 and causes the movable core 3 to separate varies each time. It had a point.

The present invention solves such conventional problems,
The purpose is to stabilize the suction and holding force of the self-holding solenoid and reduce variations in operating characteristics.

Means for Solving the Problems In order to solve the above problems, the self-holding solenoid of the present invention includes an electromagnetic coil, a substantially symmetrical fixed yoke on the outside of the electromagnetic coil, and a sliding yoke on the inside of the electromagnetic coil. A movable iron core that is freely movable, and permanent magnets with different magnetic forces that are fixed oppositely in substantially symmetrical positions between the inner surface of the fixed yoke and the movable iron core, or an electromagnetic coil and the electromagnetic core. a substantially symmetrical fixed yoke outside the coil; a movable iron core slidably provided inside the electromagnetic coil;
A permanent magnet is fixed to one side between the inner surface of the fixed yoke and the movable iron core.

Effects According to the present invention, with the above-described configuration, the direction in which the movable core is attracted by the permanent magnet and tilts is constant, and the attraction location where the movable core comes into contact is also stabilized, so that the attraction and holding force by the permanent magnet is also stabilized. This reduces the variation in operating characteristics.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

In Figures 1 and 2, 1 is an electromagnetic coil,
A substantially symmetrical fixed yoke 2 is placed on the outside of this electromagnetic coil 1.
is installed. Furthermore, a movable core 3 is inserted and slidable inside the electromagnetic coil 1, and a fixed core 4 is fixed inside the electromagnetic coil 1 and inside the fixed yoke 2 so that the end face of the movable core 3 comes into contact with the movable core 3. has been done. Furthermore, a permanent magnet 5 is fixed to one side between the inner surface of the fixed yoke 2 and the movable iron core 3. In this embodiment, the S pole of the permanent magnet 5 was adhesively fixed to the inner wall surface of the fixed yoke 2. Further, the spring 6 is configured so that a spring reaction force acts in the direction in which the movable iron core 3 is removed from the electromagnetic coil 1. 7 is a caulking plate made of brass plate.

In the above configuration, when the end face of the movable core 3 is in contact with the fixed core 4, the magnetic flux of the permanent magnet 5 passes from the movable core 3 through the fixed core 4, and further passes through the fixed yoke 2 to enter the permanent magnet 4. . At this time, there is a slight clearance between the movable core 3 and the electromagnetic coil 1 for sliding, and the movable core 3
Although it may wobble or tilt due to its clearance, it is always pulled in the direction of the permanent magnet 5, so when it comes into contact with the fixed core 4, the adsorption surface contact position of the movable core 3 is Acts to stabilize. When the movable core 3 is in contact with the fixed core 4, due to the magnetic flux of the permanent magnet 5 described above, the magnetic attraction force between the movable core 3 and the fixed core 4 is greater than the reaction force of the spring 6, and the movable core 3 is held by the fixed iron core 4 by suction. Therefore, when the electromagnetic coil 1 is momentarily energized in a direction that generates a magnetic flux in the opposite direction to the magnetic flux of the permanent magnet 5, it acts to cancel out and reduce the magnetic flux caused by the permanent magnet 5 on the attracting surfaces of the movable iron core 3 and the fixed iron core 4, and as a result, the spring 6 The movable core 3 separates from the fixed core 4 at the time when the reaction force overcomes the attraction surface magnetic force. When the self-holding solenoid is used in equipment, it is desirable that the coil current at which the movable core 3 is detached (=disengagement operating current) be constant with as little variation as possible. However, if the suction abutment surface of the movable iron core 3 is not constant and unstable during contact, as in the conventional example, the magnetic gap on the suction surface will vary each time due to repeated adsorption, and the attractive force will be inversely proportional to the square of the magnetic gap. As a result, the decoupling voltage characteristics vary. However, if the permanent magnet 5 is fixed to only one side of the inner surfaces of the movable core 3 and the fixed yoke 2 as in this embodiment, as described above, the movable core 5
This has the effect that the magnetic gap between the attracting surfaces is constant, and the dispersion of the detachment current characteristics due to repeated operation is small and stable.

Next, another embodiment of the present invention will be described with reference to FIG. The difference in FIG. 3 from the previous embodiment is that an auxiliary yoke 8 is provided at a position approximately symmetrical to the permanent magnet 5 fixed to one side between the inner surface of the fixed yoke 2 and the movable iron core 3. According to this configuration, in addition to the effect that the variation in operating current characteristics is small for the same reason as the embodiments shown in FIGS. 1 and 2,
The magnetic resistance of the magnetic path of the magnetic flux generated by energizing the electromagnetic coil 1 is reduced, which has the effect of enabling operation with low power. In other words, when a magnetic flux in the opposite direction to the magnetic flux of the permanent magnet 5 is generated by energizing the electromagnetic coil 1,
The magnetic flux passes from the fixed iron core 4 to the movable iron core, and then from the fixed yoke 2 to the fixed iron core 4 via the auxiliary yoke 8.
The auxiliary yoke 8 has a much higher magnetic permeability than the permanent magnet 5, and the magnetic resistance of the magnetic path is reduced, making it possible to control the magnetic flux of the permanent magnet 5 with a small coil current. This is because the magnetic flux of the electromagnetic coil 1 which can be canceled out by a certain amount is generated on the attraction surface between the movable iron core 3 and the fixed iron core 4.

Next, still another embodiment of the present invention will be described using FIG. 4. The difference in FIG. 4 from the previous embodiment is that a permanent magnet 5', which is slightly smaller in size, is fixed opposite to the permanent magnet 5 at a position substantially symmetrical to the permanent magnet 5. The magnetic flux of the permanent magnet increases by an amount corresponding to the permanent magnet 5', and a stronger attraction and holding force can be obtained. To the extent that the dimensions of the permanent magnets 5 and 5' are different, the magnetic force that attracts the movable iron core 3 in the lateral direction acts differently on the left and right sides, and as in the previous embodiments, the variation in the operating current characteristics is small and stable. Of course. In this embodiment, even if the dimensions of the permanent magnets 5 and 5' are the same and the magnets are made of materials with different permanent magnet characteristics, the same effect can be obtained.

Next, another embodiment of the present invention will be described with reference to FIG. The difference in FIG. 5 from the previous embodiment is that one of the permanent magnets 5' which are opposed and fixed in substantially symmetrical positions is constituted by an adjacent auxiliary yoke 8', which is similar to the previous embodiment. Due to the permanent magnets 5 and 5', a large amount of permanent magnet magnetic flux acts on the adhesion surfaces of the movable iron core 3 and fixed iron core 4, so one effect is that a strong adsorption self-holding force can be obtained, and the second effect is that the auxiliary yoke 8' acts to reduce the magnetic gap in the magnetic path through which the magnetic flux of the electromagnetic coil 1 passes, reducing magnetic resistance and allowing the movable core 3 to be detached with low power. Third, due to the difference in magnetic force between the left and right permanent magnets 5 and 5', the magnetic force that pulls the movable core 3 in the lateral direction is biased, so the position where the movable core 3 and the fixed core 4 come into contact with the attraction surfaces becomes stable. , the effect is that the variation in operating current characteristics is small.

Next, a sixth embodiment of the present invention will be described.
This will be explained using figures. The difference in FIG. 6 from the previous embodiment is that the substantially symmetrical fixed yoke 2' on the outside of the electromagnetic coil 1 is in close contact with permanent magnets 5, 5' of mutually different thickness, which are fixed oppositely in substantially symmetrical positions. According to this structure, a large amount of permanent magnet magnetic flux acts on the attracting surfaces of the movable iron core 3 and the fixed iron core 4 by the permanent magnets 5 and 5', similar to the embodiment shown in FIG. Therefore, a strong adsorption self-holding force is obtained, and the magnetic flux of the electromagnetic coil 1 passes through the magnetic path from fixed iron core 4 → movable iron core 3 → permanent magnet 5' → fixed yoke 2' → fixed iron core 4, Among these, the permanent magnet 5' with low magnetic permeability is thin, so the magnetic gap in this part is relatively small and the magnetic resistance is small, so the electric power applied to the electromagnetic coil 1 is small and the movable iron core can be detached. There is. Of course, regarding the original purpose of reducing variations in operating current characteristics, the left and right permanent magnets 5,
Because of the difference in magnetic force of
This can be achieved by stabilizing the contact position of the suction surface.

Effects of the Invention As described above, the self-holding solenoid of the present invention provides the following effects.

(1) An electromagnetic coil, a substantially symmetrical fixed yoke on the outside of the electromagnetic coil, a movable core that is slidably provided inside the electromagnetic coil, an inner surface of the fixed yoke, and the movable core. An electromagnetic coil, a substantially symmetrical fixed yoke on the outside of the electromagnetic coil, and a fixed yoke that can freely slide on the inside of the electromagnetic coil. Since the structure includes a movable iron core provided in the fixed yoke and a permanent magnet fixed to one side between the inner surface of the fixed yoke and the movable iron core, there is an effect that variations in the operating characteristics of the self-holding solenoid are small.

(2) Since it has a structure in which permanent magnets of different thicknesses are fixed to only one side of the substantially symmetrical fixed yoke or in substantially symmetrical positions, the magnetic resistance of the magnetic path of the electromagnetic coil can be reduced, so it can operate with low power. It has the unique effect of being able to

(3) Due to the above effects, it is possible to use the device stably for a long period of time using a power source with limited power such as battery drive.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a self-holding solenoid according to a first embodiment of the present invention, FIG. 2 is a front sectional view of the self-holding solenoid, and FIGS. 3, 4, 5, and 6 are according to the present invention. 7 and 8 are front sectional views of a conventional self-holding solenoid in the second embodiment. 1... Electromagnetic coil, 2, 2'... Fixed yoke, 3
...Movable iron core, 5,5'...Permanent magnet, 8,8'...
...Auxiliary yoke.

Claims (1)

[Scope of Claims] 1. An electromagnetic coil, a substantially symmetrical fixed yoke outside the electromagnetic coil, a movable iron core slidably provided inside the electromagnetic coil, and an inner surface of the fixed yoke. A self-holding solenoid consisting of permanent magnets with different magnetic forces that are fixed in opposing positions in substantially symmetrical positions between a movable iron core. 2. The self-holding solenoid according to claim 1, wherein the permanent magnets fixed opposite each other in substantially symmetrical positions are composed of permanent magnets having different dimensions. 3. The self-holding solenoid according to claim 1, wherein the permanent magnets fixed oppositely in substantially symmetrical positions are made of permanent magnets of different materials. 4. The self-holding solenoid according to claim 1, wherein one of the permanent magnets that are opposed and fixed in substantially symmetrical positions is constituted by an adjacent auxiliary yoke. 5 The approximately symmetrical fixed yoke outside the electromagnetic coil is
Claim 1, which is configured in close contact with permanent magnets having mutually different thicknesses and fixed oppositely in substantially symmetrical positions.
Self-retaining solenoid as described in section. 6. An electromagnetic coil, a substantially symmetrical fixed yoke on the outside of the electromagnetic coil, a movable iron core that is slidably provided inside the electromagnetic coil, and a space between the inner surface of the fixed yoke and the movable iron core. A self-holding solenoid consisting of a permanent magnet fixed to one side. 7. A self-holding solenoid according to claim 6, wherein an auxiliary yoke is provided at a position substantially symmetrical to a permanent magnet fixed to one side between the inner surface of the fixed yoke and the movable iron core.