JPS5811087B2 - Denjisha Yakuuchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnet device, and particularly to an electromagnet device suitable for use in a circuit breaker or the like.

In a conventional electromagnet device, as shown in FIG. 1, an electromagnetic coil 2 and a non-magnetic guide tube 3 are inserted and fixed into a yoke 1, and a movable iron core 4 is inserted into the guide tube 3.

A stopper 6 is provided at the lower end of the yoke 1 via a support fitting 5 to contact the lower surface of the movable core 4 in the open position.

Normally, at least one of the support fitting 5 and the stopper 6 is made of non-magnetic metal.

A non-magnetic pole plate 7 is fixed to the upper end of the movable iron core 4, and a knocking rod 8 is provided at the upper part of the pole plate 7 to penetrate through the yoke 1 and take out an output.

The roller 9 is an output transmission part and has a gap g1 between it and the knocking rod 8.

Now, when a voltage is applied to the electromagnetic coil 2, a current flows through it, and as shown in FIG. When the movement reaction force A due to its own weight is exceeded, the movable iron core 4 strokes upward by the gap g1 and collides with the roller 9.

Therefore, the operational reaction force W1 of the electromagnet device is created by adding the operational reaction force A at the roller 9 to the operational reaction force A due to its own weight, and B
However, when the current in the electromagnetic coil 2 increases and the electromagnetic attractive force M exceeds this operational reaction force 8, the movable iron core 4 further strokes.

By the way, when such an electromagnet device is used as a closing device for a circuit breaker, the reaction force at point B is usually smaller than the maximum reaction force, and the reaction force at point B is overcome. Even if the coil current that generates the electromagnetic attraction force M for The output of the electromagnetic device has not reached a sufficient value.

Therefore, depending on the value of the reaction force applied in the latter half of the stroke of the movable core 4, even if the movable system obtains kinetic energy in the shaded area F shown in FIG. 2, this kinetic energy may be sufficient to overcome the drag energy in the shaded area G. If you do not exceed this, you will not be able to get a complete stroke.

In particular, when applied to a circuit breaker with a short circuit current exceeding 40 KA, the solid contact contacts the movable core 4 in the latter half of its stroke, but the maximum reaction force considering the electromagnetic repulsion force at this time is the reaction force at point B. This can be up to 10 times more difficult, making a complete stroke even more difficult.

Therefore, conventional electromagnet devices are designed to ignore the operational reaction force at the beginning of the stroke and overcome the maximum reaction force, but the coil current that flows when the movable core 4 is started is
Since this is only about 25 to 40% of the coil's steady current, it cannot be solved unless the design has sufficient margin, making the electromagnet device large and requiring a large-capacity coil power supply, which is uneconomical. .

It has also been proposed to provide an electromagnet or a permanent magnet that attracts and holds the movable iron core in its open position, and to use this attraction and holding force to apply an operational reaction force at the beginning of the stroke of the movable iron core (for example, Japanese Utility Model Publication No. 39-32599 issue,
(Refer to Utility Model Publication No. 39-32598).

However, this electromagnet device requires an expensive attracting and holding electromagnet or permanent magnet in addition to the main electromagnet, making the device expensive.

In addition, the attraction and holding force of the movable iron core by the electromagnets and permanent magnets for attraction and holding only works when the holding air gap on the lower surface of the movable iron core is very small, that is, at the very beginning of the movement of the movable iron core, and the knocking rod is attached to the roller. By the time the stroke reaches the position where the reaction force due to the load can be obtained by collision, the force has become almost zero.

Therefore, there is a problem in that the suction holding force and the load on the roller cannot be applied simultaneously as a reaction force, and the load on the roller cannot be effectively used as a reaction force.

An object of the present invention is to eliminate the drawbacks of the prior art and provide a small, lightweight, and inexpensive electromagnetic device.

To achieve this objective, the present invention provides a main movable iron core (first
A second movable core for applying a reaction force is provided separately from the movable core), and this second movable core is opposed to the yoke through a gap shorter than the full stroke of the first movable core. , at the beginning of the stroke until the second movable core collides with the yoke, the first and second movable cores move upward together due to the magnetic attraction between these two movable cores; By configuring the movable core to separate the second movable core and move upward independently, the movement due to the weight of the first movable core can be achieved with a simple structure of simply providing an inexpensive second movable core. In addition to the reaction force, a large operational reaction force can be applied only at the beginning of the stroke, including the magnetic attraction between the first and second movable cores, the weight of the second movable core, and the operational reaction force due to the roller load. It is characterized by the following.

An embodiment of the present invention will be described below with reference to FIG.

The configuration of the yoke 1, electromagnetic coil 2, guide cylinder 3, movable iron core 4, pole plate 7, knocking rod 8, and roller 9 is as follows.
Although it is similar to the conventional electromagnetic device shown in the figure, the following magnetic attraction device is provided in order to apply an operational reaction force only at the beginning of the stroke of the movable core 4.

In other words, a second movable core different from the movable core 4 (first movable core)
A movable iron core 10 is provided so as to be movable using a non-magnetic stopper 6 as a guide.

The second movable core 10 is in contact with the lower surface of the first movable core 4 at its open position, and has a gap g2 larger than the gap g1 between the second movable core 10 and the lower surface of the yoke 1.

In the electromagnet device configured in this way, when a voltage is applied to the electromagnetic coil 2, a current flows through it and a magnetic flux Φ as shown by the dotted line is generated, and the first movable iron core 4 and the second movable iron core 10 An electromagnetic attractive force acts between the second movable core 10 and the second movable core 10, but by appropriately designing the second movable core and the gap g2, this electromagnetic attracting force can be made sufficiently larger than the weight of the second movable core 10.

Therefore, as shown in FIG. 4, as the coil current increases, the electromagnetic attractive force M that overcomes the operational reaction force A' due to the weight of the first and second movable iron cores 4°10 and the knocking rod 8 increases. 1 and 2nd movable iron cores 4, 10 and yoke 1
These movable members 4, 8, 10 stroke by the gap g1 and collide with the roller 9.

Here, since the operational reaction force at the roller 9 is added and the operational reaction force W of the electromagnet device reaches point B', the coil current increases until it overcomes this, and the electromagnetic attraction force due to this current causes the movable member 4, 8 and 10 further stroke together by g2-g1.

Here, since g2=0, the operational reaction force W of the electromagnet device
In addition to the operational reaction force due to the weight of the movable member and the operational reaction force on the rollers, there is also an operational reaction force due to the attraction force of the attached magnetic attraction device, that is, the first movable iron core 4 and the second movable iron core 10. The electromagnetic attractive force acting between the two points is further applied, increasing from point B' to point C.

Therefore, the coil current further increases, and when the electromagnetic attraction force M of the first movable core 4 exceeds this operational reaction force at point C, the first movable core 4 is separated from the second movable core 10 and becomes independent. However, along with this stroke, the electromagnetic attractive force between the first and second movable cores 4 and 10 rapidly decreases.

In FIG. 4, the curve W2 represents the operational reaction force due to the added magnetic attraction device, that is, the operational reaction force due to the own weight of the second movable core 10, and the electromagnetic force between the first and second movable cores 4, 10. It shows the action reaction force plus the attraction force (acts as action reaction force).

As described above, the first movable iron core 4 starts to operate with sufficient output, and the operational reaction force decreases rapidly at the beginning of the stroke, so the movable system strokes with a large kinetic energy as shown by the shaded area F'. The drag energy shown by the shaded area G' at the top also becomes smaller, allowing the maximum reaction force to be easily overcome and a complete stroke to be made.

As explained above, according to the present invention, the second movable core for applying an operational reaction force is provided below the yoke and faces the yoke with a gap shorter than the entire stroke of the first movable core. , at the beginning of the stroke until the second movable core collides with the yoke, the first and second movable cores move together due to the magnetic attraction between these two movable cores, and after that, the first and second movable cores move together. Since the iron core is configured to separate from the second movable iron core and move upward independently, the simple structure of simply providing an inexpensive second movable iron core eliminates the movement reaction caused by the weight of the first movable iron core. In addition to the force, the magnetic attraction force between the first movable core and the second movable core, the second
It is possible to apply a large reaction force, which is the weight of the movable iron core and the reaction force due to the load on the rollers, only at the initial stage of the stroke.

As a result, the movable core can be activated after sufficiently increasing its output, improving efficiency and making it possible to manufacture an electromagnetic device that is small, lightweight, and inexpensive.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a conventional electromagnet device, Fig. 2 is a characteristic diagram showing its acting force, Fig. 3 is a longitudinal sectional view of an electromagnet device showing an embodiment of the present invention, and Fig. 4 is its action. It is a characteristic diagram showing force. Explanation of symbols: 1... Yoke, 2... Electromagnetic coil, 4... First movable iron core, 6...
...Stopper, 8...Knocking rod, 9.
...Roller, 10...Second movable iron core.

Claims (1)

[Claims] 1 a yoke, an electromagnetic coil attached to the yoke,
In an electromagnet device including a first movable core that is attracted upward by the energization of the electromagnetic coil, the yoke and The second one for applying opposing motion reaction force.
A movable core is provided, and at the beginning of the stroke until the second movable core collides with the yoke, the first and second movable cores move upward together due to the magnetic attraction between the two movable cores. However, after that, the first movable core is configured to pull out the second movable core and move upward independently, and the weight of the second movable core and the gap between the first movable core and the second movable core are An electromagnet device characterized in that an operation reaction force due to a magnetic attraction force is applied only at the initial stage of a stroke.