JPH0722047B2 - Electromagnetic actuator - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic actuator using a permanent magnet used in a gas flow interrupting device and the like.

2. Description of the Related Art Conventionally, as a power saving type electromagnetic actuator, a permanent magnet is used to maintain a state, and an electromagnetic coil of a type used only for instantaneous excitation is used. In particular, in recent years, there is a growing demand for the electromagnetic actuator as a gas cutoff valve of a microcomputer gas cutoff device that cuts off gas by using a built-in battery power source in a meter for measuring gas consumption and controlling the gas with a microcomputer. In particular, when interlocking with a gas leak alarm or when monitoring the safe use of gas, a signal indicating the operating state of the electromagnetic actuator is often required.

FIG. 5 shows a conventional example of an electromagnetic actuator capable of extracting a signal of an operating state, in which the south poles of two permanent magnets 1a and 1b are arranged opposite to each other, and the north poles of both permanent magnets 1a and 1b are outwardly directed. U-shaped yoke 4 is disposed in contact with the fixed core 2, the fixed iron core 2 is fixed substantially at the center of the bottom surface of the yoke 4, and the permanent magnets 1a and 1b face each other.
A movable iron core 3 is arranged so that the center of the pole is taken and it can be attracted to the fixed iron core 2, and the permanent magnet 1, the yoke 4, the fixed iron core 2 and the movable iron core 3 are arranged.
Then, the magnetic circuit A is formed by the permanent magnet, and the movable iron core 3 is attracted and held to the fixed iron core 2 on the attracting surface 10. An electromagnetic coil 5 is arranged around the movable iron core 3, and by applying a current, the movable iron core 3 is excited in the direction opposite to the magnetic circuit A by the permanent magnet, and the attraction force on the attraction surface 10 is reduced. Fixed iron core 3
The spring bearing 9 is fixed to the spring bearing 9, and the spring 8 is compressed and disposed between the spring bearing 9 and the permanent magnet 1. As a result of the reduction of the attraction force on the attraction surface 10 due to the current application to the electromagnetic coil 5,
Finally, the reaction force of the spring 8 becomes larger than the attraction force, the movable iron core 3 separates from the attraction surface 10, and the electromagnetic actuator operates. One terminal of the reed switch 7 is arranged near the S pole of the permanent magnet 1b, and the other terminal is arranged near the yoke 4. In the state where the movable iron core 3 is adsorbed and held by the fixed iron core 2, the magnetic circuit A by the permanent magnet is a closed circuit,
The leakage flux to the outside of the yoke 4, the fixed iron core 2 and the movable iron core 3 is relatively small and is not sufficient to magnetize and operate the reed switch 7, so that the reed switch 7 is in an inoperative state. In the operating state in which the movable iron core 3 is separated from the fixed iron core 2, the magnetic circuit A by the permanent magnet does not become a closed circuit, and the leakage magnetic flux is relatively large, and a part of this leakage magnetic flux is a permanent magnet 1b.
Permanent magnet from the N pole through the yoke 4 and reed switch 7.
A magnetic circuit B passing through the reed switch 7 reaching the S pole of 1b is formed. Therefore, the reed switch 7 is magnetized and the reed switch 7 is in the operating state.

As described above, the reed switch 7 can be used to extract the operating or non-operating state of the electromagnetic actuator as an electrical signal.

FIG. 6 shows another conventional example of an electromagnetic actuator in which a U-shaped yoke 4a is disposed so that the bottom surface is in contact with the S pole of the permanent magnet 1, and a flat plate having a hole in the center is in contact with both ends of the yoke 4a. The yoke 4b is arranged, the fixed iron core 2 is arranged in contact with the N pole of the permanent magnet 1, the movable iron core 3 is arranged so as to be attracted to the fixed iron core 2 through the hole of the yoke 4b, The magnet 1, the fixed iron core 2, the movable iron core 3, and the yokes 4b and 4a form a magnetic circuit A by a permanent magnet, and the movable iron core 3 is attracted to and held by the fixed iron core 2 on the attraction surface 10. Electromagnetic coil 5 with movable iron core 3
The movable iron core 3 is excited in the opposite direction to the magnetic circuit A by the permanent magnet by applying a current to the movable iron core 3 to reduce the attraction force on the attraction surface 10, and the movable iron core 3 is moved by the reaction force of the spring 8. The magnetic actuator separates from the adsorption surface 10 and the electromagnetic actuator operates.

The electromagnetic actuator shown in FIG. 6 has a simple structure as compared with the electromagnetic actuator shown in FIG. 5, has stable operation, and an expensive permanent magnet may be small in size.

Problems to be Solved by the Invention However, in the electromagnetic actuator of FIG. 6, the S pole side of the permanent magnet 1 is the yokes 4a, 4b and the movable iron core 3 during operation, while the N pole side is the fixed iron core 2 in operation. The fixed iron core 2 and the yoke to which the reed switch 7 representing the operation of the electromagnetic actuator as shown in FIG.
It will not operate unless it is placed between 4a or 4b, or between the fixed iron core 2 and the movable iron core 3. However, since the movable iron core 3 is covered with the electromagnetic coil 5, the reed switch cannot be arranged close to it. Further, since the yoke 4b is close to the fixed iron core 2 and a relatively large amount of magnetic flux is constantly leaked, the reed switch is likely to be always in operation or not to operate at all. It is difficult to determine the arrangement in which the switch will operate. For this reason, there is a problem that it is practically almost impossible to obtain information on the operating and non-operating states of the electromagnetic actuator of FIG. 6 by using the reed switch.

The present invention solves the above-mentioned problems of the conventional example, and an object thereof is to electrically obtain a signal indicating the operating state of an electromagnetic actuator without hindering the operation of the electromagnetic actuator.

Means for Solving the Problems In order to solve the above problems, the present invention provides a magnetic circuit formed by at least a permanent magnet, a fixed iron core, a movable iron core, and a yoke, the magnetic circuit including the permanent magnet, and the movable iron core. An electromagnetic coil arranged to enclose the movable iron core by applying a current, a detecting means for detecting an operating state of the movable iron core, the permanent magnet, the fixed iron core, a detecting means yoke, a detecting means, An electromagnetic actuator having a magnetic circuit formed by the yoke and passing through the detecting means is provided.

Action According to the configuration of the electromagnetic actuator of the present invention, in the non-operating state in which the fixed iron core and the movable iron core are attracted to each other, the magnetism of the permanent magnet formed by the permanent magnet, the fixed iron core, the movable iron core, and the yoke is generated. Since the circuit is a closed circuit, the magnetic flux passing through the magnetic circuit passing through the fixed iron core, the detecting means yoke, the detecting means and the detecting means formed via the yoke is relatively less than the permanent magnet, and the detecting means is Does not work.
On the other hand, in an operating state in which the movable iron core is separated from the fixed iron core, the magnetic circuit generated by the permanent magnet does not become a closed circuit, and thus the magnetic flux generated from the permanent magnet is transferred from the fixed iron core to the movable iron core. Alternatively, a magnetic path that passes through a magnetic gap in air from the fixed iron core to the yoke is formed. At this time, since the detecting means yoke is near the fixed iron core, the magnetic gap of the magnetic circuit passing through the detecting means becomes sufficiently smaller than the magnetic gap of the magnetic circuit of the permanent magnets, and the magnetic flux has a high magnetic resistance. Rather than passing through, it passes through a magnetic circuit that goes through the detection means, which has a lower reluctance. Therefore, since the magnetic flux passing through the magnetic circuit passing through the detecting means is relatively large, the detecting means operates. In this way, the detection means can be used to extract the operating or non-operating state of the electromagnetic actuator as an electric signal.

Embodiment Hereinafter, an electromagnetic actuator according to an embodiment of the present invention will be described with reference to the drawings.

The electromagnetic actuator of one embodiment of the present invention has a structure as shown in FIG. 1 or 2. A U-shaped yoke 4a is arranged in contact with the S pole of the permanent magnet 1 at the bottom, a flat plate yoke 4a having a hole in the center is arranged in contact with the yoke 4a, and is connected to the N pole of the permanent magnet 1. The fixed iron core 2 is arranged, the movable iron core 3 is arranged so as to be capable of adsorbing the fixed iron core 2 through the hole of the yoke 4b,
Permanent magnet 1, fixed iron core 2, movable iron core 3, yokes 4a, 4b
Then, the magnetic circuit A is formed by the permanent magnet 1, and the movable iron core 3 is attracted to and held by the fixed iron core 2 on the attraction surface 10. An electromagnetic coil 5 is arranged surrounding the movable iron core 3, and by applying a current, the movable iron core 3 is excited in the direction opposite to the magnetic circuit A by the permanent magnet 1 to reduce the attracting force on the attracting surface 10 and the spring 8 The movable iron core 3 is separated from the attracting surface 10 by the reaction force of, and the electromagnetic actuator operates. FIG. 1 is a diagram showing a state where the electromagnetic actuator is not operating, and FIG. 2 is a diagram showing a state where the electromagnetic actuator is operating. A reed switch yoke 6 is arranged near the fixed iron core 2, and a reed switch 7 is provided between the reed switch yoke 6 and the yoke 4b.
Is provided, the permanent magnet 1, the fixed iron core 2, the reed switch yoke 6, the reed switch 7, and the yokes 4a, 4a.
A magnetic circuit B passing through b and the reed switch is formed.

As shown in FIG. 1, in a non-operating state of the electromagnetic actuator in which the fixed iron core 2 and the movable iron core 3 are attracted, the magnetic circuit A by the permanent magnet 1 is a closed circuit, so that the reed switch 7 is turned on. The magnetic flux passing through the passing magnetic circuit B is relatively small and the reed switch 7 does not operate. On the other hand, in the operating state in which the movable iron core 3 is separated from the fixed iron core 2 as shown in FIG. 2, the magnetic circuit A by the permanent magnet 1 does not become a closed circuit, so the magnetic flux generated from the permanent magnet 1 is fixed. A magnetic path that passes through the magnetic gap in the air is formed from the iron core 2 to the movable iron core 3 or from the fixed iron core 2 to the yoke 4a. At this time, since the reed switch yoke 6 is in the vicinity of the fixed iron core 2, the magnetic gap of the magnetic circuit B passing through the reed switch 7 becomes sufficiently smaller than the magnetic gap of the magnetic circuit A by the permanent magnet 1, and the magnetic flux has a magnetic resistance. Rather than passing through high air, it passes through a magnetic circuit through a reed switch with a lower reluctance. Therefore, the reed switch 7
Since the magnetic flux passing through the magnetic circuit B passing through is relatively large, the reed switch 7 operates as shown in FIG. In this way, the reed switch 7 can be used to extract the operating or non-operating state of the electromagnetic actuator as an electric signal.

Next, an electromagnetic actuator of another embodiment of the present invention is shown in FIG. The same parts as those of the electromagnetic actuator shown in FIG. 1 or 2 are designated by the same reference numerals, detailed description thereof will be omitted, and different parts will be mainly described. As shown in FIG. 3, the reed switch yoke 6a is arranged near the fixed iron core 2, the reed switch yoke 6b is arranged near the reed switch yoke 6a, and the yoke 4b is extended. The reed switch yoke 6c is arranged in a shape, the reed switch 7 is arranged between the reed switch yoke 6b and the reed switch yoke 6c, the permanent magnet 1 is used, the fixed iron core 2, the reed switch yoke 6a, Reed switch yoke 6b,
Reed switch 7, reed switch yoke 6c, yoke
A magnetic circuit passing through the reed switches via 4a and 4b is formed. With the configuration of the electromagnetic actuator as shown in FIG. 3, the reed switch 7 can be used to extract the operating or non-operating state of the electromagnetic actuator as an electric signal as in the electromagnetic actuator of FIG.

Furthermore, an electromagnetic actuator of another embodiment of the present invention is shown in FIG. The same parts as those of the electromagnetic actuator shown in FIG. 1 or 2 are designated by the same reference numerals, detailed description thereof will be omitted, and different parts will be mainly described. Forming a reed switch yoke 6d having a magnetic body and having a male screw 11,
A female screw portion 12 is provided on a part of the non-magnetic coil bobbin 5a,
The magnetic gap of the magnetic circuit B passing through the reed switch 7 can be changed by inserting the reed switch yoke 6d therein and rotating the reed switch yoke 6d to move the position of the reed switch yoke 6d.
As a result, variations in the total magnetic flux of the permanent magnet 1 and variations in the moving value of the reed switch 7 can be absorbed, and the operation of the reed switch 7 can be stabilized. Therefore, the reed switch 7 is used to activate and deactivate the electromagnetic actuator. The operating state can be reliably taken out as an electric signal.

Effects of the Invention As described above, according to the present invention, since the reed switch yoke is provided and the magnetic circuit passing through the reed switch is provided, the following effects can be expected.

(B) Where it was difficult to obtain information on the operating and non-operating states of the electromagnetic actuator using a reed switch, a fixed iron core and a yoke were inserted between the permanent magnets in the magnetizing direction of the permanent magnet. Information on the operating or non-operating state of the electromagnetic actuator having the arranged structure can be easily taken out as an electric signal by using a reed switch.

(B) By appropriately setting the shape of the reed switch yoke, restrictions on the location of the reed switch can be relatively reduced.

(C) By moving the position of the reed switch yoke, variations in the total magnetic flux of the permanent magnets and variations in the reed switch impression value are absorbed, and the reed switch is used to activate and deactivate the electromagnetic actuator. Can be reliably taken out as an electric signal.

[Brief description of drawings]

FIG. 1 is a cross-sectional view in which a main part of an electromagnetic actuator showing one embodiment of the present invention is cut away, FIG. 2 is a cross-sectional view in which a main part showing an operating state of the electromagnetic actuator in FIG. 1 is cut out, and FIG. FIG. 4 is a sectional view of a notch of an essential part of an electromagnetic actuator showing another embodiment of the present invention, FIG. 4 is a sectional view of an electromagnetic actuator showing another embodiment of the present invention, and FIGS. 5 and 6 are conventional electromagnetic actuators. FIG. 3 is a cutaway sectional view of a main part of FIG. 1 ... Permanent magnet, 2 ... Fixed iron core, 3 ... Movable iron core, 4
...... Yoke, 5 ... Electromagnetic coil, 6 ... Reed switch yoke, 7 ... Reed switch, A ... Magnetic circuit with permanent magnet, B ... Magnetic circuit passing through reed switch.

Claims (3)

[Claims] 1. A magnetic circuit formed by at least a permanent magnet, a fixed iron core, a movable iron core, and a yoke, and a magnetic circuit formed by encasing the movable iron core. The movable iron core is excited by applying a current. An electromagnetic coil for detaching the movable iron core from the fixed iron core; a detecting means for detecting an operating state of the movable iron core; the permanent magnet, the fixed iron core, a detecting means yoke, the detecting means, and the yoke. An electromagnetic actuator having a magnetic circuit formed by the above-mentioned detection means. 2. A fixed iron core and a yoke are arranged so as to sandwich the permanent magnet in the magnetizing direction of the permanent magnet, and a detection means yoke is arranged in the immediate vicinity of the fixed iron core. The electromagnetic actuator according to claim 1, wherein the detecting means is provided between the detecting means yoke and the detecting means yoke. 3. The electromagnetic actuator according to claim 1, wherein the magnetic gap of the magnetic circuit passing through the detecting means can be changed by moving the position of the detecting means yoke.