JPS6345726Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic device for a small electromagnetic circuit breaker for protecting a circuit, generally called a circuit protector, and more particularly to a device having a voltage coil and a current coil.

A conventional electromagnetic circuit breaker having a voltage coil and a current coil has a voltage coil 1 as shown in FIG.
and current coil 2 are arranged coaxially, and a common armature 3
The movable contact 6 is separated from the fixed contact 5 by the trip cutoff mechanism 4.
To explain each part in more detail, the voltage coil 1 is wound around a cylindrical winding frame 7 made of non-magnetic synthetic resin, and is connected to voltage terminals 8 and 9. The current coil 2 is similarly wound around a cylindrical winding frame 10 made of non-magnetic synthetic resin, one end of which is connected to the current terminal 11, and the other end connected to a conductive movable arm 13 using a flexible copper braid 12. It is connected to the. Since the arm 13 is provided with a movable contact 6, the other end of the current coil 2 is connected to the other current terminal 14 when the pair of contacts 5 and 6 are on.

A delay magnetic core 15 is arranged at the center of the voltage coil 1 and the current coil 2 to delay the operation of the electromagnet to attract the armature 3. This delay magnetic core 15 is generally called a delay tube, and includes a bottomed cylindrical body 16 made of non-magnetic brass,
A fixed core 17 serving as a magnetic pole is inserted into the upper part of the cylindrical body 16, and when the current coil 2 is not attracting, the fixed core 17 is located at the lower part of the cylindrical body 16, separated from the fixed coil 1, and is attracted by the current coil 2. A movable core 18 that sometimes moves to contact the fixed core 17, a coil spring 19 that biases the movable core 18 downward, and silicone oil injected into the cylindrical body 16 to apply braking to the movable core 18. It consists of a viscous liquid 20. In order to reduce the delay time of the tripping operation based on the voltage coil 1, the fixed core 17 is connected to the voltage coil 1.
It is inserted so that it approximately corresponds to the length of the solenoid. That is, the fixed core 17 is arranged to serve as the magnetic core of the voltage coil 1. Furthermore, the movable core 18 is disposed below so as not to be substantially responsive to the voltage coil 1.

Reference numeral 21 denotes a frame made of a magnetic material, which is formed in an L-shape as shown in FIG.
has a hole 22 through which the delay magnetic core 15 is inserted, the rising portion 21b of which is formed along the side surfaces of the current coils 1 and 2, and the armature 3 is rotatably attached to the upper end thereof. Supporting part 2
It has 1c. Attachment of the armature 3 to the frame body 21 is achieved by supporting the shaft 23 at the support portion 21c and rotatably mounting the armature 3 on the shaft 23. The armature 3 is biased clockwise in FIG. 1 by a torsion spring 24 wound around a shaft 23. However, when the portion 3a of the armature 3 hits the frame 21, the separated position shown in FIG. 1 is determined. One end 3b of the armature 3 on the left side of the shaft 23 is movable from the separated position shown in FIG. 1 to the upper end of the fixed core 17, that is, the magnetic pole 17a,
When the armature 3 is attracted to the magnetic pole 17a while the trip cutoff mechanism 4 is kept on, the right end 3c of the armature 3 hits the trip cutoff mechanism 4, resulting in a tripping operation.

The trip cutoff mechanism 4 includes a movable arm 13 coupled to a fixed shaft 25, a spring 26 that biases the arm 13 counterclockwise, a link 27 coupled to the arm 13, and a U-shaped link coupled to the link 27. 28, cam 2 supported by link 28
9. A rotatable shear pin 30 provided on the link 28 and with which the cam 29 selectively engages, a striker bar 31 fixed to the pin 30 and struck by the armature 3, and rotatably supported on the shaft 32. and comprises a handle 33 connected to link 28. Note that 34 is an insulating plate and 35 is a case. This type of trip cutoff mechanism 4 is known, for example, from Japanese Utility Model Application No. 52-8169.

The circuit breaker configured as shown in FIG.
Generally, it is connected to an electrical circuit as shown in FIG.
That is, the voltage coil 1 is connected in parallel to the electric circuit, the current coil 2 is connected in series to the circuit, and the contacts 5 and 6 are turned off in the event of overvoltage and overcurrent.

In the circuit breaker of FIG. 1, the contacts 5 and 6 can be turned on and off by the handle 33, and can also be turned off by the current coil 2 and the voltage coil 1. First, when a relatively small overcurrent is flowing through the current coil 2, the movable core 18, the frame 21, the armature 3, and the fixed core 1
The movable core 18 is attracted to the fixed core 17 by the magnetic path consisting of 7. That is, the spring 19 and the viscous liquid 2
0, the movable core 18 moves toward the fixed core 17 with a delay time, and when it comes into contact with the fixed core 17, the magnetic resistance suddenly decreases, so the magnetomotive force increases, and the magnetic pole 17a It becomes possible to attract the armature 3. Therefore, in the case of a small overcurrent, a trip operation is performed with a delay time, and it does not respond to a short-term overcurrent. Also, when a large current flows through the current coil 2, the movable core 18 moves to the fixed core 17.
A magnetomotive force capable of attracting the armature 3 is generated even when the armature 3 is not in contact with the armature, and the trip operation is performed with substantially no delay.

On the other hand, when a voltage higher than a predetermined value is applied to the voltage coil 1, the fixed core 17, the movable core 18, and the frame 2
1 and the armature 3, the armature 3 is attracted to the magnetic pole 17a and trip-operated. The number of turns of the voltage coil 1 is set so that the armature 3 can be attracted even if the movable core 18 is not attracted to the fixed core 17. By the way, in the magnetic path by the voltage coil 1, the fixed core 17 and the movable core 1
Since there is a gap between the 8 and 8, leakage magnetic flux increases. Therefore, in order to increase the response speed, it was necessary to increase the number of turns of the voltage coil 1. Therefore, the size of the device has increased.

Therefore, an object of the present invention is to provide an electromagnet device that can downsize an electromagnetic circuit breaker having a voltage coil and a current coil.

To achieve the above object, the present invention includes a voltage coil configured to interrupt a circuit in response to a voltage exceeding a predetermined value, and a voltage coil configured to interrupt the circuit in response to a current exceeding a predetermined value. a current coil disposed coaxially adjacent to the voltage coil; a non-magnetic cylindrical body inserted through the centers of the voltage coil and the current coil; and at least a portion of the cylindrical body serving as a magnetic core of the voltage coil. a fixed core inserted into the upper part of the cylindrical body, and a fixed core located at a lower position of the cylindrical body away from the fixed core when not attracted by the current coil, and the fixed core when attracted by the current coil. a movable core formed to contact or be close to the current coil; a magnetic frame provided along the lower part of the current coil and a part of the outer periphery of the voltage and current coil; an armature coupled to the cylindrical body, one end of which is rotatably supported so as to take a position in contact with or close to the upper end of the cylindrical body, and a position away from the upper end of the cylindrical body, and biased so as to maintain the armature in the separated position; The present invention relates to an electromagnetic device for turning off an electromagnetic circuit breaker comprising a magnetic thin plate interposed between the voltage coil and the current coil.

According to the present invention, by inserting a magnetic thin plate between the current coil and the voltage coil, the response characteristics of the electromagnet caused by the voltage coil are enhanced without substantially inhibiting the action of the electromagnet caused by the current coil. becomes possible. In other words, a magnetic path consisting of a fixed core, a magnetic thin plate, a frame, and an armature is formed as the magnetic path of the electromagnet by the voltage coil, and as leakage magnetic flux is reduced, the response characteristics are improved and the response characteristics are the same as before. In this case, it becomes possible to significantly reduce the number of turns of the voltage coil.

Next, FIGS. 4 and 5 showing an electromagnetic circuit breaker according to an embodiment of the present invention will be described. however,
Components denoted by numerals 1 to 35 in FIG. 4 are substantially the same as those denoted by the same numerals in FIG. 1, so their explanation will be omitted. In this embodiment, a magnetic thin plate 36 having a hole 37 is inserted between the voltage coil 1 and the current coil 2. This magnetic thin plate 3
6 is made of a silicon steel plate with a thickness of 0.1 mm, is arranged between the voltage coil winding frame 7 and the current coil winding frame 10, and the cylindrical body 16 is inserted into the hole 37. Since the diameter of the magnetic thin plate 36 is approximately equal to the diameter of the winding frames 7 and 10, its outer peripheral end is close to the frame body 21. Note that the maximum cross-sectional area of the thin plate 36 is set to be significantly smaller than the cross-sectional area of the fixed core 17, for example, set to a fraction of one to several tenths, preferably in the range of 1/3 to 1/50. .

In the configuration shown in FIG. 4, the voltage coil 1
When a voltage higher than a predetermined value is applied to the fixed core 1
7. A magnetic path consisting of the thin plate 36, the frame 21, and the armature 3 is formed, and the leakage magnetic flux is reduced. Therefore, even if the number of turns of the voltage coil 1 is reduced by about 30%, it will not be the same as the voltage coil 1 in FIG. It becomes possible to perform a similar voltage trip operation. Therefore, it becomes possible to downsize and reduce the cost of the device.

Note that even if the thin plate 36 is provided, the tripping operation by the current coil 2 hardly changes. That is, since the cross-sectional area of the thin plate 36 is much smaller than the cross-sectional area of the fixed core 17, the thin plate 36 can be ignored. To explain this in more detail, when a small current is flowing through the current coil 2, the armature 3 is not attracted immediately, and the movable core 18 is moved to the fixed core 17.
be inhaled when in contact with. Therefore, movable core 1
Even if a closed magnetic path consisting of the movable core 18, the thin plate 36, and the frame 21 is formed before the movable core 8 comes into contact with the fixed core 17, it has almost no relation to the attraction of the armature 3. At the time when the movable core 18 contacts the fixed core 17, since there is a large difference in the cross-sectional area between the fixed core 17 and the thin plate 36, most of the magnetic flux passes through the fixed core 17, and the armature 3 Sudden suction. Even if a large overcurrent flows through the current coil 2, the thin plate 36 can be ignored.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto and can be further modified. For example, the configuration may be such that the viscous liquid 20 for braking the movable core 18, the return spring 19, etc. are omitted. Further, the rising portion 21b of the frame body 21 may be formed in a semicircular shape. Also thin plate 3
6 may be shaped like the bottom surface portion 21a of the frame body 21. In short, it is only necessary to dispose it partially or entirely between the cylindrical body 16 and the frame body 21. Further, the trip cutoff mechanism 4 may be various mechanisms other than those in the embodiment. Further, the length of the fixed core 17 may be about half the length of the voltage coil 1, or
It may also extend into the current coil 2.

[Brief explanation of drawings]

Figure 1 is a partially longitudinal front view of a conventional circuit breaker.
2 is a circuit diagram showing an example of the electrical connection of the circuit breaker shown in FIG. 1; FIG. 3 is a perspective view showing the frame shown in FIG. 1;
FIG. 4 is a partially longitudinal front view showing a circuit breaker according to an embodiment of the present invention, and FIG. 5 is a perspective view showing the thin plate of FIG. 4. In the symbols used in the drawings, 1 is a voltage coil, 2 is a current coil, 3 is an armature, 4 is a trip cutoff mechanism, 16 is a cylindrical body, 17 is a fixed core, 18 is a movable core, and 21 is a movable core. The frame 36 is a magnetic thin plate.

Claims (1)

[Claims for Utility Model Registration] A voltage coil configured to interrupt a circuit in response to a voltage exceeding a predetermined value, and a voltage coil configured to interrupt the circuit in response to a current exceeding a predetermined value, and a current coil arranged coaxially adjacent to the current coil; a non-magnetic cylindrical body inserted through the centers of the voltage coil and the current coil; and at least a portion of the cylindrical body extending from the top of the cylindrical body to serve as a magnetic core of the voltage coil. an inserted fixed core, which is located at a lower position of the cylindrical body away from the fixed core when not attracted by the current coil, and which is located at a lower position of the cylindrical body away from the fixed core when attracted by the current coil; a movable core formed to be in contact or close to each other; a magnetic frame provided along a lower part of the current coil and a part of the outer periphery of the voltage and current coil; and a magnetic frame provided along the upper part of the frame. an armature that is coupled and rotatably supported so that one end of the armature is in contact with or close to the upper end of the cylindrical body and a position that is apart from the upper end of the cylinder, and that is biased so as to maintain the armature in the separated position; An electromagnet device for turning off an electromagnetic circuit breaker, comprising: a magnetic thin plate interposed between the voltage coil and the current coil.