JPS63146415A - Electromagnetic actuator - Google Patents

Abstract

PURPOSE:To enhance the conversion efficiency of an applying voltage by disposing a regulating yoke rotatable at a fixed core as a center between the core disposed on a permanent magnet and a yoke thereby to reduce the magnetic resistance near the permanent magnet of an electromagnetic coil. CONSTITUTION:A magnetic circuit A in which a magnetic path is formed of a permanent magnet 1, a stationary core 3, a movable core 2, first and second yokes 4a, 4b is formed, and the core 2 is attracted at its attracting surface 9 against the repelling force of a compression spring 7 to the core 3. A magnetic circuit B in which a magnetic path is formed of a regulating yoke 5 rotatable at the core 3 as a center and yokes 4a, 4b is formed of an electromagnetic coil 6. Then, since the directions of the magnetic fluxes of the circuits A, B are reverse on the attracting surface 9, the yoke 5 is rotated at the core 3 as a center thereby to vary the magnetic resistance of a regulating magnetic circuit C, thereby varying the attracting force F of the surface 9.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electromagnetic actuator used in gas cutoff devices, gas cutoff valves for gas appliances, and the like.

BACKGROUND OF THE INVENTION Electromagnetic actuators have been widely used as safety devices for gas appliances. Furthermore, in recent years, there has been an increasing demand for electromagnetic actuators as gas cutoff valves for microcomputer gas cutoff devices that detect abnormal usage or gas leaks and shut off gas. In particular, power-saving self-holding electromagnetic actuators using permanent magnets are becoming increasingly useful in systems using battery power sources, such as gas shutoff devices.

Generally, an electromagnetic actuator has a structure as shown in the conventional example shown in FIG. A permanent magnet 1, a fixed iron core 3 made of magnetic material, a movable iron core 2, a first yoke 4&, and a second yoke 4b1 are arranged to form a magnetic circuit A of annular permanent magnets. The movable iron core 2 is attached to the fixed iron core 3 on the suction surface 9 against the repulsive force fsp of the compression spring 7 which is compressed and arranged between the spring receiver 8 attached to the core 2 and the second yoke 4b. It holds by adsorption. An electromagnetic coil is placed inside the first yoke 4a surrounding the movable iron core 2.
L/6 is arranged, and by applying a current, a magnetic field is generated inside the electromagnetic coil/L/6, and a magnetic circuit B by the electromagnetic coil p is formed in the opposite direction to the magnetic circuit A by the permanent magnet 1.

Its working principle is that when a signal voltage is applied to both ends of the electromagnetic coil/L/6, the magnetic flux # due to the magnetic circuit B by the electromagnetic coil is
Since b is generated on the attracting surface 9 in the opposite direction to the magnetic flux #a caused by the magnetic circuit A of the permanent magnet, the total magnetic flux on the attracting surface 9 -
decreases, and the attraction force r between the movable iron core 2 and the fixed iron core 3 on the attraction surface 9 decreases with the applied voltage value V, and the attraction force r falls below the repulsive force fsp of the compression spring. At this time, the movable iron core 2 is no longer able to maintain the suction/holding state on the suction surface 9 and leaves the suction surface 9, causing the electromagnetic actuator to operate. The operating voltage value Vact at this time is the most important characteristic value that determines the operating characteristics of the electromagnetic actuator.

The relationship between the above applied voltage value V and magnetic flux -a, my, a, and the applied voltage V, attraction force F, and repulsive force of the compression spring fsp17
) relationships are shown in Figures 4 and 5, respectively.

Problems to be Solved by the Invention However, in the conventional configuration, the magnetic resistance of the magnetic circuit B caused by the electromagnetic coil/I/6 is particularly large in the part of the permanent magnet 1, and therefore, the magnetic resistance applied to the electromagnetic coil/L/6 is particularly large. The magnetic field generated by the current was not effectively converted into magnetic flux -b by the magnetic circuit B, and the change in the attraction force F with respect to the change in the voltage value V applied to the electromagnetic coil/1/6 was small. For example, in order to obtain a certain operating voltage value Vact, the repulsive force fsp of the compression spring must be set high, and there is a high risk that the electromagnetic actuator will malfunction due to external vibrations. Conversely, if the repulsive force fsp of the compression spring is set low to improve earthquake resistance, the operating voltage Vact will increase. When used as an actuator for a device that aims to ensure maintenance-free operation, it places a heavy burden on the power source such as a battery, which impairs the operational reliability of the device as a whole.

Determining the operating voltage Vact as described above is important in determining the matching between the device and the electromagnetic actuator. However, due to variations in the magnetic properties of the permanent magnet 6, movable iron core 2, fixed iron core 3, first yoke 4a, second yoke 4b, etc., and variations in the dimensions and surface conditions of each component, the magnetism caused by the permanent magnet 1 Circuit A and electromagnetic coil /L/
Since the magnetic resistance of the magnetic circuit B due to the electromagnetic actuator 6 varies, it is difficult to estimate the operating voltage Vact before assembling the electromagnetic actuator. For this reason, in the assembly manufacturing process, several types of compression springs 7 with different repulsive forces are prepared, and if the measured value of the operating voltage Vact deviates from the standard value, the compression spring 7 is replaced with another compression spring 7 with a different repulsive force. By doing so, the operating voltage Vact was managed. However, when the above construction method is used, the storage space for the compression spring 7 becomes large,
There is a problem in that the manufacturing cost increases because the number of man-hours required to replace the compression spring 7 increases.

At the same time, since it is impossible to finely adjust the operating voltage Vact after assembly, it is difficult to match the device with other devices.

As shown above, the conventional configuration has the following problems.

B. The conversion efficiency of the applied voltage V was poor, making it difficult to achieve both energy saving and earthquake resistance.

Since the opening 1 operating voltage Vact' is adjusted by replacing the compression spring 7, the manufacturing cost is high.

C. Since the operating voltage Vact cannot be adjusted after manufacturing,
It was difficult to match the equipment.

The present invention solves the above conventional problems and provides an electromagnetic actuator whose operating voltage can be changed and finely adjusted.

Means for Solving the Problems In order to solve the above problems, the present invention provides a magnetic circuit A using the permanent magnets, which is formed of a permanent magnet, a fixed iron core made of a magnetic material, a movable iron core, and a yoke; a compression spring attached to the movable iron core and compressed between the yoke; an electromagnetic coil disposed surrounding the movable iron core and exciting the movable iron core by applying a current; A magnetic circuit B formed by the electromagnetic coil arranged between the yokes and formed by the fixed iron core, the movable iron core, and the yoke.
and an adjustment magnetic circuit formed by the permanent magnet, the fixed iron core, and the yoke, and an adjustment made of a magnetic material that can change the magnetic flux of the adjustment magnetic circuit by rotating around the fixed iron core. This constitutes an electromagnetic actuator equipped with a yoke.

According to the structure of the present invention, the magnetic circuit B made of the electromagnetic coil passes through the adjustment yoke made of a magnetic material with low magnetic resistance rather than passing through the air with high magnetic resistance avoiding the permanent magnet with high magnetic resistance from the yoke. Since the coil is directed toward the fixed iron core, the magnetic resistance of the magnetic circuit formed by the electromagnetic coil is small, and the magnetic field generated by the current applied to the electromagnetic coil is effectively converted into magnetic flux by the magnetic circuit formed by the electromagnetic coil p. Therefore, the change in the adsorption force between the fixed iron core and the movable iron core is large in response to a change in the voltage value applied to the electromagnetic coil.
Since a low operating voltage can be obtained even if the repulsive force of the compression spring is weak, it is easy to achieve both energy saving and earthquake resistance.

Further, according to the configuration of the present invention, the magnetic flux by the permanent magnet is distributed from the fixed iron core to the magnetic circuit by the permanent magnet passing through the movable iron core and the adjusting magnetic circuit passing through the adjusting yoke, and the adjusting yoke is connected to the fixed iron core. By rotating around the iron core, the magnetic resistance of the adjusting magnetic circuit is changed, and the ratio of the magnetic flux passing through the magnetic circuit by the permanent magnet to the magnetic flux passing through the adjusting magnetic circuit is changed, and the fixed iron core and the adjusting magnetic circuit are changed. Since the magnetic flux passing through the attraction surface with the movable iron core is changed, it is possible to change the attraction force.

Therefore, it is possible to change the operating voltage without changing the repulsive force of the compression spring, and it is also possible to finely adjust the operating voltage even after the electromagnetic actuator is assembled.

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

An electromagnetic actuator according to an embodiment of the present invention has a structure as shown in FIG. Permanent magnet 1, fixed iron core 3 made of magnetic material, movable iron core 2, first yoke 4a, second yoke 4b
are arranged to form an annular magnetic circuit A of the permanent magnet 1, and the magnetic circuit A of the permanent magnet compresses and disposes the spring receiver 8 attached to the movable iron core 2 and the second yoke 4b. The movable iron core 2 is suctioned and held by the fixed iron core 3 on the suction surface 9 with the suction force F against the repulsive force f@p of the compression spring 7. An electromagnetic coil/I/6 is arranged inside the first yoke 4a surrounding the movable iron core 2, and by applying a current, a magnetic field is generated inside the electromagnetic coil/L/6, and the movable iron core 2 , by an electromagnetic coil/I/6 that passes through an adjustment yoke 6 made of magnetic material that is arranged surrounding the fixed iron core a1 and is rotatable around the fixed iron core 3, the first yoke 4a, and the second yoke 4b. A ring-shaped magnetic circuit B is formed. The magnetic circuit B formed by this electromagnetic coil is in the opposite direction to the magnetic circuit A formed by the permanent magnet 1 on the attraction surface 9 . At the same time, the adjustment yoke 5 is moved by the permanent magnet 1 to the fixed iron core 3,
An adjustment magnetic circuit C passing through the adjustment yoke 5 and the first yoke 4a is formed. An example of the shape of the adjustment yoke 5 is shown in FIG. 2 and FIG.
Since the magnetic flux -b caused by the permanent magnet 1 is generated on the attraction surface 9 in the opposite direction to the magnetic flux #a caused by the magnetic circuit A of the permanent magnet 1, the attraction surface 9
The total magnetic flux at is decreased, and the attraction force F is decreased with the applied voltage value V. When the attraction force F is lower than the repulsive force fsp of the compression spring 7, the movable iron core 2 is moved to the attraction surface 9. The suction holding state cannot be maintained, the suction surface 9 is detached, and the electromagnetic actuator is activated.

The applied voltage V at this time is set as the operating voltage Vact.

The relationship between the above applied voltage value V and the magnetic fluxes ·a, ·b, and the relationship between the applied voltage V, the attraction force F, and the repulsive force fsp of the compression spring are shown in FIGS. 4 and 5, respectively.

According to FIG. 4, in the present invention, since the adjustment yoke 5 is used to reduce the magnetic resistance near the permanent magnet 1 of the magnetic circuit B by the electromagnetic coil, the magnetic flux by the magnetic circuit B by the electromagnetic coil with respect to the change in the applied voltage V - It can be seen that the change in b is large, indicating that the electrodynamic energy conversion efficiency is high.

Furthermore, according to FIG. 5, since the adjustment yoke 5 is used in the present invention, the change in the adsorption force F with respect to the change in the applied voltage V is large. In this case, the operating voltage Vact is the conventional example Vac.
e' can be significantly reduced, which is an advantageous characteristic for energy saving.For example, when the operating voltage is set to the same as that of the conventional example, the repulsive force of the compression spring can be made smaller than that of the conventional example, which improves earthquake resistance. It can be seen that the results are improved.

On the other hand, the magnetic flux -M due to the permanent magnet is adjusted by the adjustment yoke 5.
g is distributed from the fixed iron core 3 to the magnetic flux -a caused by the magnetic circuit A of the permanent magnet that passes through the movable iron core 2, and the magnetic flux -〇 caused by the adjustment magnetic circuit C that passes through the adjustment yoke 5. By rotating around 3, the magnetic resistance of the adjustment magnetic circuit C is changed, the ratio between -a and -C is changed, and the magnetic flux -a passing through the attraction surface 9 is changed, thereby changing the attraction force F. Is possible.

Therefore, it is possible to change the operating voltage Vact without changing the repulsive force fsp of the compression spring 7.

For example, when using the adjustment yoke 5 shown in FIG. 2 or another example of adjustment yoke 5a, the first yoke 4
Adjustment yoke 50 angle θ with respect to a and magnetic flux -a, #c, #
The relationship between Mg, the relationship between the angle θ of the adjustment yoke 5 and the attraction force F, and the relationship between the angle θ and the operating voltage Vact are shown in FIGS. 6, 7, and 8, respectively. However, the angle θ is 90°
shown in the range.

As shown in Fig. 8, by rotating the adjustment yoke 5,
The operating voltage V without changing the repulsive force fsp of the compression spring 7.
act can be changed, and since the adjustment yoke 5 can be rotated even after the electromagnetic actuator is assembled, it can be seen that fine adjustment of the operating voltage can be easily made.

In the above embodiment, a case has been described in which the inside of the electromagnetic coil/I/6 is used as a guide when the movable iron core 2 moves away, but the electromagnetic coil tv6, the movable iron core 2, and the fixed iron core 3 It is also possible to provide a guide pipe made of a non-magnetic metal material between them to guide the movable iron core 2. In that case, the guide pipe can be located between the fixed iron core 3 and the adjusting yoke 5, or the fixed iron core 3 and the adjusting yoke 6 can be in direct contact.

Effects of the Invention As described above, the following effects can be expected from the present invention.

B. The applied voltage conversion efficiency is high, and it is easy to combine energy saving and earthquake resistance.

Since the operating voltage can be adjusted by rotating the adjustment yoke,
The cost can be reduced compared to the conventional example in which the manufacturing cost increases due to the replacement of the compression spring.

C. Since the operating voltage can be adjusted after manufacturing, it is easy to match with other devices.

[Brief explanation of the drawing]

FIG. 1 is an overall cross-sectional view of an electromagnetic actuator according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of an adjustment yoke according to an embodiment of the present invention, and FIG. 3 is an adjustment according to another embodiment of the present invention. FIG. 4 is an exploded perspective view of the yoke. FIG. 4 is a diagram showing the relationship between applied voltage and magnetic flux according to an embodiment of the present invention and a conventional example. FIG. 5 is a diagram showing the relationship between applied voltage and magnetic flux according to an embodiment of the present invention and a conventional example. FIG. 6 is a diagram showing the relationship between the angle of the adjustment yoke and magnetic flux according to an embodiment of the present invention, and FIG. 7 is a diagram showing the relationship between the angle of the adjustment yoke and the attraction force according to an embodiment of the present invention. 8 is a diagram showing the relationship between the angle of the adjustment yoke and the operating voltage according to an embodiment of the present invention, and FIG. 9 is a general sectional view of a conventional electromagnetic actuator. 1...Permanent magnet, 2...Movable iron core, 3
...Fixed iron core, 4...Yoke (4a,
...1st yoke, 4b...2nd yoke)
, 5... Adjustment yoke, 6... Electromagnetic coil μ, 7... Compression spring, A... Magnetic circuit with permanent magnet, B... ...Magnetic circuit using electromagnetic coil, C... Adjustment magnetic circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person3-
1! It iron 4 1 yoke yoke 2 yoke 8 - spring support 9 - song fa c-vi + * filtration circuit busy - magnetic sail rotation %Al: jru magnetic flux 田楤ふ尀の畷着〃 fsp - compression spring The repulsion! -Permanent magnet i3 diagram Suga present invention 1; can be placed! a-Permanent magnet 1; Magnetic flux due to the feeding circuit! l, - Salt coil - Vact - Operating voltage F - D fsp - Compression spring repulsion force Fig. 4 Fig. 5 Applied voltage V e]it Tsuji V Fig. 6 frl) - Permanent 7 magnet 1: Dwelling gutter Shuhong - Permanent magnet 1: Due to the magnetic circuit, the angle θ Fig. 7 iml! Angle of yoke θ Figure 8 ljXθ of training yoke

Claims (1)

[Claims] A magnetic circuit A by the permanent magnet formed by a permanent magnet, a fixed iron core made of magnetic material, a movable iron core, and a yoke; a compression spring attached to the movable iron core and compressed between the yoke; an electromagnetic coil arranged surrounding the movable iron core and exciting the movable iron core by applying a current; and an electromagnetic coil arranged between the fixed iron core and the yoke, the fixed iron core, the movable iron core, and the yoke. and a magnetic circuit B formed by the electromagnetic coil, an adjusting magnetic circuit formed by the permanent magnet, the fixed iron core, and the yoke, and a magnetic flux of the adjusting magnetic circuit by rotating around the fixed iron core. An electromagnetic actuator with a changeable adjustment yoke made of magnetic material.