JPS59158506A - Electromagnet - Google Patents

Abstract

PURPOSE:To avoid the vibration noise, heat generation and consumption of electric power and obtain a simple composition by providing a permanent magnet which can attract a movable core against the force of a recovering spring and a current control circuit which supply an electromagnet coil a pulse current whose polarity is changed in accordance with the operation of a switch. CONSTITUTION:A permanent magnet 9, which can attract a movable core 4 against the expansion force of a recovering spring 5, is provided to a pole head of an electromagnet core 2. When a main contact 13 is closed, an auxiliary contact 14a is opened and a charging current i1 is applied to an electromagnet coil 1 to charge a capacitor 21 and the flux, whose direction is the same as that of the permanent magnet 9, is induced in the electromagnet core 2 and the movable core 4 is attracted by the permanent magnet 9. The charging current i1 is gradually reduced according to the charge of the capacitor 21 but the movable core 4 is kept to be attracted even after the charging current i1 becomes null. When the closing contact 13 is opened, the auxiliary contact 14a is closed accordingly and the charge stored in the capacitor 21 is discharged and the discharge current i2 flows through the electromagnet coil 1, the auxiliary contact 14a, a diode 22 and a variable resistor 23 and the original state is recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electromagnet device constituting a device, such as an electromagnetic contactor or breaker, which opens and closes an electric circuit using electromagnetic force.

[Technical background of the invention]

As shown in Fig. 1, this type of electromagnet device has a bar-shaped electromagnet core 2 wrapped around an electromagnet coil 1, which is attached to the center inside an electromagnetic yoke 3 bent into a U-shape. A movable core 4 is integrated with the electromagnetic coil 1 and whose free end approaches and separates from the pole head of the electromagnetic core 2 is supported so as to be tiltable. A return spring 5 is provided that applies torque to the movable iron core 4. In addition, a movable contact (not shown) such as a vacuum switch 7 is disposed in a direction intersecting the free end of the arm 6, and the movable shaft 7a and the free end of the arm are connected to the wipe spring 8. The movable shaft 7a is coupled through the movable shaft 7a in such a manner that the movable shaft 7a can be pushed up.

Further, this electromagnet device has a current control circuit shown in FIG.

That is, a rectifier 12 is connected to a power source 11, and an electromagnetic coil 1 is connected between the output terminals of the rectifier 12 via a closing contact 13 and a current limiting resistor 15. A delay operation contact 14 which closes with a delay with respect to the movable shaft 7a is connected to the electromagnetic filter 1, and a surge suppressor circuit consisting of a resistor 16 and a capacitor 17 connected in series L- is connected in parallel to the electromagnetic filter 1.

The operation of this electromagnet device will be explained below.

First, when the closing contact 13 is closed, the output voltage of the rectifier 12 is applied to both ends of the electromagnet coil 10 via the closing contact 13 and the delay operation contact 14, so that the closing current determined by the internal resistance and inductance of the electromagnet filter 1 is As the electromagnetic core 2 is magnetized, the movable core 4 is attracted to the pole head of the electromagnetic core 2. At the time of this attraction, the upper left end of the electromagnetic iron 3 bent into a U-shape, as shown in the drawing, is also close to the movable iron core 4 to form a closed magnetic path. Furthermore, when the movable core 4 is attracted to the electromagnetic core 2, the arm 6 also rotates in the direction of arrow A in conjunction with the electromagnetic core 2, pushing the movable shaft 7a upward in the drawing via the wipe spring 8. .

Then, the vacuum switch 7 is closed and a closing operation is performed. At this time, the wipe spring 8 serves to apply appropriate contact pressure to the internal contacts.

When the closing operation is completed in this way, the delayed operation contact 14 is opened, and from this point on, a holding current is applied to the electromagnetic coil 1 through the closing contact 13 and the resistor 15 to maintain the movable iron core 4 in the attracted state. continues to be supplied.

Thus, when VC is turned on, a large current sufficient to attract the movable core 4, which is far from the electromagnet core 2, flows through the electromagnet coil SE1, but once the movable core 4 has been attracted, a smaller current is sufficient. For this reason, the resistor 15 is interposed to suppress the current value to a low value, thereby reducing power consumption.

Next, during a so-called return operation in which the vacuum switch 7 is opened, the closing contact 13 is opened and the current flowing through the electromagnetic coil is cut off. Therefore, the magnetic flux of the electromagnet core 2 also disappears, and the movable core 4 is returned to its original position σ away from the pole head of the electromagnet core 2 by the return spring 5. At this time, the arm 6 moves in conjunction with the movable iron core 2 in the direction of the arrow B in Fig. 1, and the movable shaft 7a is pulled down to the lower blade in the figure. .

By the way, when opening the closing contact 13, the electromagnetic coil 1
Since a surge voltage having an extremely large peak value compared to the normal circuit voltage is generated across the circuit, this voltage is suppressed to a low level by a surge suppressor circuit consisting of a resistor 16 and a capacitor 7, and the contact 13 and the electromagnetic coil Protect 1.

[Problems with background technology]

In such a conventional electromagnet device, since a pulsating current flows through the electromagnet coil and the attraction force to the movable core 4 fluctuates, collisions between the electromagnet cores 2 and \\ are repeated and vibration noise is generated. there were.

Furthermore, when the vacuum switch 7 is held in the closed state, a holding current continues to flow through the resistor 15, generating Joule heat and causing power loss, which is uneconomical.

On the other hand, a surge suppressor circuit is an essential element, which complicates the configuration of the device.

In addition, in order to keep the vibration noise, heat generation, and power loss as mentioned above low, there are some systems that use a mechanism to mechanically latch the movable core 4 at the end of the closing operation, but this method is not suitable. However, there was a drawback that a new trip coil, etc. was required, making the structure more complicated.

[Objective of the Invention] The present invention was made to eliminate the drawbacks of the conventional ones in terms of construction, and to provide an electromagnet device that can prevent vibration noise, heat generation, and waste of power, and can simplify the configuration. purpose.

[Summary of the invention]

In order to achieve this object, the electromagnet device of the present invention includes an electromagnetic core, an electromagnetic filter wound around the electromagnetic core, and a movable core supported so as to be able to move toward and away from the pole head of the electromagnetic core. , a return spring that applies a force in the direction of separating the movable iron core from the pole head of the electromagnet core; The present invention is characterized by a configuration including a permanent magnet that can be attracted against the force of the return spring, and a current control circuit that supplies a lasing current in different directions to the electromagnetic coil in response to a switch operation. Zuru.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 3 is a side view showing the structure of an electromagnet device according to the present invention, in which the same reference numerals as in FIG. 1 indicate the same elements. The difference from FIG. 1 is that a permanent magnet 9 is provided at the pole head of the electromagnetic core 2 to attract the movable core 4 against the tension of the return spring 5.

Moreover, FIG. 4 shows the configuration of a current control circuit that supplies an operating current to the electromagnetic coil 1 of this contact operating section, and the power supply 11.
A closing contact 1 is connected between the output terminals of the rectifier 12 connected to
3. The electromagnetic coil 1 and the capacitor 21 are connected in series in this order, and the closing contact 13 and the reverse operation '1 are connected at both ends of the series circuit of the electromagnetic coil 1 and the capacitor 21.
A discharge circuit including a filter auxiliary contact (normally closed contact) 14a, a diode 22, and a variable resistor 23 connected in series is connected in parallel.

The operation of the electromagnet device constructed as described above will be explained below with reference to the time charts shown in FIGS. 5 and 6.

First, the strength of the permanent magnet 9, the distance between the movable iron core 4 and the permanent magnet 9, and the strength of the return spring 5 are appropriately selected or adjusted so as to satisfy the following conditions.

a) When the movable iron core 4 is returned to its stand, the movable iron core 4 is not attracted by the attractive force of the permanent magnet 9 alone.

b) The movable core 4 is attracted only when a magnetic flux in the same direction as the magnetic flux of the permanent magnet 9 is generated in the electromagnetic core 2.

C) Once the movable iron core 4 has been attracted, the permanent magnet 9 continues to attract the movable iron core 4 only.

d) When a magnetic flux in the opposite direction to the magnetic flux of the permanent magnet 9 is generated in the electromagnet core 2, the movable core 4 is moved by the action of the return spring 5.
will return.

Here, when the closing contact 13 is closed, the auxiliary contact 14a is opened, but due to the closing of the closing contact 13, the capacitor 21 is charged to the polarity shown, and the electromagnetic coil 1 receives the photocurrent 1]. flows. This photoelectric current! 1, magnetic flux is generated in the electromagnetic core 2 in the same direction as the permanent magnet 9, and the movable core 4 is attracted to the permanent magnet 9.

As is well known, the charging current 11 reaches its maximum immediately after closing the closing contact 3, and thereafter gradually decreases as the capacitor 21 is charged until the maximum voltage of the rectifier 12 and the voltage across the capacitor 210 become equal. It becomes zero when

In this case, since the internal resistance of the electromagnetic coil 1 is relatively small, a substantially pulsed current flows through the electromagnetic coil 1.

In this way, even if the photocurrent 11 becomes zero, the movable iron core 4 continues to be attracted by the permanent magnet 9, so that the vacuum switch 7 is maintained in the closed state.

Next, when the closing contact 13 is opened to disconnect the electromagnetic coil 1 from the flow director 2 in order to open the vacuum switch 7, the auxiliary contact 14a closes and the current is stored in the capacitor 21. The discharge current 12 flows through the electromagnet coil 1, the auxiliary contact 14a, the diode 22, and the variable resistor 23.

This discharge current I2 is the charging current 11 at the time of turning on.
In the electromagnetic core 2, magnetic flux is generated in the opposite direction to the permanent magnet 9, and when the magnetic flux of the permanent magnet 9 is almost canceled, the movable core 4 is affected by the return spring 5 as shown in the figure. return to the original state.

Here, the diode 22 is for flowing the discharge current I2 in a predetermined direction, and may be removed depending on the circuit conditions. Further, the variable resistor 23 prevents the permanent magnet 9 from being demagnetized when an excessive current of 1 VC flows through the electromagnet coil, and the peak value can be appropriately determined by adjusting the resistance value.

By the way, most electromagnetic coils used in this type of electromagnetic device have an inductance of about 1 and a DC resistance of about 1Ω. By using a capacitor with a capacitance of 2000 [μF] for the electromagnet coil 1, it is possible to obtain input current characteristics comparable to those of conventional electromagnet devices.

Figures 5 (a) and (b) show the closing contact 13 and the auxiliary contact 1.
4a, and FIG. 5(C) shows a waveform diagram of the current flowing through the electromagnetic coil 1 in response to these contact operations.

That is, if the closing contact 13 is repeatedly opened and closed as shown in FIGS. As shown in (C), immediately after the closing contact 13, a pulsed charging current 1 flows, and immediately after opening the closing contact 13, a discharge current 12 in the opposite direction flows. Note that, compared to the charging current 11 , the peak value of the discharging current 12 is smaller due to the presence of the variable resistor 23 .

Next, FIG. 6 shows the closing current characteristics of the conventional electromagnet device and the electromagnet device according to the present invention, and the closing time of this type of device is often set to approximately 50 (msec). In the conventional device, as shown by the broken curve A, a current close to the rated value flows when so[m5ec:] has passed.

On the other hand, in the electromagnet device of the present invention, as shown by the solid curve B, the current reaches its maximum at the time when (,50 (:m5ec)) passes, and moreover, the current flows close to the rated value.

In other words, the inductance is 1 [H] and the DC resistance is 50 [H].
By connecting a 2000 CμF) capacitor in series with a 2000 CμF) electromagnetic coil, it is possible to perform the same operation as the conventional device, even if the electromagnetic coil has a slightly different rating. The above-described configuration can be employed in most types of electromagnetic equipment.

〔Effect of the invention〕

As is clear from the above explanation, according to the electromagnet device of the present invention, the movable iron core is attracted by one pulse of current,
In addition, since this movable iron core is continuously attracted by a permanent magnet, vibration and noise at the time of insertion can be reliably prevented, and power can be saved since no holding power is required.

In addition, although conventional devices required a surge suppressor circuit, the electromagnetic device of the present invention does not require this surge suppressor circuit, and the newly added elements can be of low voltage resistance. The configuration is significantly simplified.

On the other hand, compared to devices with conventional mechanical latching mechanisms aimed at power saving, there is no need for tri-lag coils and their adjustment, resulting in a simpler configuration that increases reliability and reduces costs. You can get excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional side view of the configuration of a conventional electromagnet device for a vacuum switch, Fig. 2 is a circuit diagram showing the configuration of a current control circuit of this electromagnet device, and Fig. 3 is an electromagnet according to the present invention. Partially sectional side view of the configuration of one embodiment of the device, No. 4
The figure is a circuit diagram showing the configuration of the current control circuit of the same embodiment.
Figures (a) to (C) are time charts for explaining the action of the same embodiment, and Fig. 6 is an input current characteristic diagram shown together with the conventional device for explaining the action of the same embodiment. . 1... Electromagnetic coil, 2... Electromagnetic core, 3...
Electromagnetic yoke, 4... Movable iron core, 5... Return spring, 6
... Arm, 7... Vacuum switch, 8... Wipe spring, 9... Permanent magnet, 11... Power supply, 12... Rectifier, 13... Closing contact, 14... delayed action contacts,
14. l...Auxiliary contact, 15°16...Resistor, 1
7, 21... Capacitor, 22... Diode,
23...variable resistor. Applicant's agent Kiyoshi Inomata Figure 1 C Figure 2 Figure 5 Darkness → f (sec)

Claims (2)

[Claims] (1) An electromagnetic core, an electromagnetic coil wound around the electromagnetic core, a movable core supported so as to be able to move toward and away from the pole head of the electromagnet core, and a movable core supported at the pole head of the electromagnet core. A return bar that applies a force in a direction to pull the electromagnetic core away from the part is provided on the pole head of the electromagnetic core, and is capable of attracting the movable core that is in contact with the pole head against the force of the return spring. An electromagnet device comprising: a permanent magnet; and a current control circuit that supplies pulsed currents in different directions to the electromagnetic coil in response to switch operations. (2) The current control circuit includes at least a capacitor connected in series with the electromagnetic coil, and charges or discharges the capacitor via the electromagnetic filter to apply pulsed currents in different directions to the electromagnetic filter. An electromagnetic device according to claim 1, characterized in that it is provided with an electromagnetic device.