JPS6164034A - Overcurrent detector of circuit breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to improvements in overcurrent detection devices for circuit breakers such as wiring breakers, circuit protectors, current limiters, and switches.

(Background of the Invention) Conventionally, circuit breakers for wiring can be roughly divided into two types based on their operating principles: a thermal tripping mechanism that uses a bimetal to trip the gate due to a sustained overcurrent, and an electromagnetic type tripping mechanism for overcurrent detection. It incorporates an overcurrent detection device consisting of an electromagnetic tripping mechanism that uses a coil to attract the movable iron core due to overcurrent, and an opening/closing mechanism that instantly disconnects using the operating handle, allowing for shutoff operations depending on the situation. It is configured to be carried out.

As such a circuit breaker, one shown in FIG. 6, for example, is known.

In the same figure, a power supply side terminal 22 and a load side terminal 23 are arranged on a base 21, and between these, an opening/closing mechanism AIfi consisting of a link □ structure 24 and a handle 25 is provided, and below this, a bimetal 26 Thermal type tripping using g! j, a structure 27 is provided, and an electromagnetic coil 28, two movable iron pieces, a fixed iron core 30, and a movable iron core 31 are arranged side by side.
An electromagnetic type tripping mechanism 32 consisting of the following is provided. A fixed contact 33 and a movable contact 34 are disposed facing each other between the electromagnetic tripping mechanism 32 and the power supply side terminal 22. Further, below these, an arc extinguishing device 35 is disposed for extinguishing the arc when the arc is cut off.

The movable core 31 is designed to be attracted to the fixed core 30 when the electromagnetic coil 28 is excited when an overcurrent is applied. The movable contact 34 is inserted into the inserted insertion hole and engaged with the movable contact 34 by a knob 31b provided at the tip of the outer shaft 31a, thereby separating the movable contact 34 from the fixed contact 33.

Further, one end of the link mechanism 24 of the opening/closing mechanism A is engaged with a trip plate 36 to constitute a latch mechanism, thereby suppressing rotation of the link mechanism 24. This trip plate 36 is configured to be able to interlock with the bimetal 26 and the two movable iron pieces separately, so that the bimetal 26 is deformed when an overcurrent is applied, or the movable iron core 31 attracted by the electromagnetic coil 28 is connected to the movable iron piece. It is configured to rotate by pressing 29. When the trip plate 36 rotates, the latch R1fX is released, the link mechanism 24 is operated, and the movable contact 34 is separated from the fixed contact 33.

However, the conventional wiring circuit breaker as described above had the following drawbacks.

That is, when an overcurrent is applied, it is required to forcibly open the movable contact 34 and release the latch mechanism to maintain the forcibly opened movable contact 34 in the released state. Then, the suction operation of one movable iron core 31 presses the movable iron piece 26 via the electromagnetic part inner shaft 31c interlocked with this, and rotates the trip plate 36 above it, thereby releasing the latch mechanism. At the same time, the movable iron core 31
It is adapted to engage with the movable contact 34 via b. Therefore, if the movable core 31 forcibly opens the movable contact 34 first, the power to the electromagnetic coil 28 is cut off, the attractive force of the movable core 31 is lost, and the movable contact 34 returns to the fixed contact state. Since the movable contact 34 will come into contact with the child 33, the movable contact 34 must be opened after the latch mechanism supporting the movable contact 34 is released to prevent the movable contact 34 from returning. can't do it. Therefore, in the conventional type, the movable iron core 31 connects the movable contact 3 through the knob 31b.
4 so that the latch mechanism can be removed before engaging.
The gap X provided between the knob 31b of the movable iron core 31 and the movable contact 34 is the gap between the movable iron piece 26 and the trip plate 36.
It is the sum of the amount of play between y, the amount of play in the iron piece (26), the amount of BU (y), and the amount of latch mechanism tripping (2). In particular, a considerable amount of play is required in consideration of variations in component dimensions up to the latch part, and therefore the distance until the movable iron core 31 engages with the movable contact piece 34 is very large. It has become. Therefore, in the conventional overcurrent detection device, the response time until forced opening increases, which is a problem.

In addition, in order to achieve high-performance breaking, it is necessary to provide a larger forced opening distance between the movable contact and the fixed contact.However, in the conventional configuration, the movable iron core and As the gap between the contacts increases,
Since the opening distance, which is the distance the movable contact moves after engaging the movable iron core, is relatively reduced, it is difficult to increase the forced opening distance beyond a certain level, and this is also a big problem. It had become.

(Object of the Invention) An object of the present invention is to solve the above-mentioned drawbacks of the prior art, shorten the response time until forced opening of the movable contact when overcurrent is applied, and reduce the forced opening of the movable contact at that time. An object of the present invention is to provide a high-performance overcurrent detection device for a circuit breaker with an expanded opening distance.

(Features of the invention) The circuit of the present invention! The overcurrent detection device for the 7i device includes a fixed iron core and a movable iron core provided within the electromagnetic coil, and a movable iron piece that is attracted to the fixed iron core and releases the latch mechanism between the fixed iron core and the latch mechanism. In addition, by adopting a configuration in which a minute gap is formed between the engaging portion of the movable iron core and the movable contact, the latch mechanism is released and the movable contact is opened simultaneously and independently, and the movable contact This shortens the response time to forced opening and increases the strong v1 opening distance of the movable contact.

(Embodiment of the Invention) An embodiment of the overcurrent detection device according to the present invention as described above will be specifically described with reference to FIGS. 1 to 5.

In FIG. 1, a power supply side terminal 2 and a load side terminal 3 are arranged on a base 1, and an opening/closing mechanism A consisting of a link mechanism 4 and a handle 5 is provided between these terminals. Below this opening/closing mechanism A, a thermal type tripping mechanism 7 using a bimetal 6 is provided, and an electromagnetic type tripping mechanism 7 consisting of an electromagnetic coil 8, a movable iron piece 9, a fixed iron core 10, and a movable iron core 11 is arranged side by side. A removal mechanism 12 is provided respectively. A fixed contact 13 and a movable contact 14 are disposed facing each other between the electromagnetic tripping mechanism 12 and the power source terminal 2. Further, below these, an arc extinguishing device 15 is disposed for extinguishing the arc when the arc is cut off.

The movable iron piece 9 is configured to be attracted to the fixed iron core 10 and rotate counterclockwise in the figure when an overcurrent is applied, and a trip plate 17 that forms a latch mechanism with the link mechanism 4 is provided at the upper end of the movable iron piece 9. , engages with one movable iron piece in a counterclockwise direction, and the latch mechanism is released at that time.

A knob 11b is provided at the tip of the outer shaft 11a of the flexible 8 iron core 11 inserted into the insertion hole of the movable contact 14, and the gap X between the knob 11b and the movable contact 14 is only a small amount of play. When the movable core 11 is attracted to the fixed core 10, the movable core 11 and the movable contact 14 immediately engage, and the knob 11b presses the movable contact 14. is configured to separate from the fixed contact 13.

- Also, the upper end 14a of the movable contactor 14 is connected to a guide 14b formed in an arc shape on the side surface of the base 1, as shown in FIG.
It is slidably inserted inside. And link mechanism 4
When the power is turned on, the movable contact 1
4 is biased towards the fixed contact 13 by a main spring 16 provided between its upper part and the base, centering on the connection part 14c with the link mechanism 4. Further, when the link mechanism 4 moves to the closing position, the connecting portion with the link mechanism 4 becomes free, and the movable contact 14 is biased in the disconnecting direction by the main spring 16 around the upper end 14a. It looks like this.

On the other hand, the link mechanism 4 constitutes a latch mechanism together with the trip plate 17, thereby suppressing the rotation of the link mechanism 4. This trip plate 17 is separately linked to the bimetal 6 and the movable iron piece 9, and is configured to rotate when either of the latter is activated. When the trip plate 17 rotates, the latch mechanism is disengaged and the link mechanism 4 is moved to the cutoff position.

The present invention having the above configuration has the following effects.

First, when performing a cutoff operation from a closed state as shown in FIG. 1, the handle 5 is moved in the cutoff direction, which is to the left in the figure, as shown in FIG. When the handle 5 is moved, the link machine 11N! 4 moves to the cut-off position, the tip of the link mechanism 4 comes off from the trip plate 17, and the link mechanism 4 moves to the cut-off position. As a result, the movable contact 14 is rotated around the main spring 1 with the upper [14a as the center].
6 in the breaking direction and separates from the fixed contact 13, thereby performing breaking. FIG. 4 is a schematic diagram of FIG. 3.

Next, in this example, sustained overcurrent or excessive current,
When the bimetal 6 or the movable iron piece 9 is activated by a short-circuit current, the trip plate 17 interlocked with these rotates in the direction of releasing the latch mechanism, and the tip of the link mechanism 4 is released. becomes tripped in a very short time as shown in FIG. In particular, when the electromagnetic plunger operates and the movable iron piece 9 is attracted to the fixed iron core 10, the trip plate 17 immediately rotates counterclockwise and the latch mechanism is released. Compared to the latch release operation in the conventional configuration, this operation requires fewer members and there is no play between the members, resulting in a significant reduction in time.

At the same time, when the movable iron core 11 is attracted and moves by a small amount of play X, the knob 11b engages and presses the movable contact 14, and moves the movable contact 14 away from the fixed contact 13. They are separated and cut off.

In this way, since the movable contactor 14 can be moved by the movable J iron core 11 independently and almost simultaneously with the release of the link mechanism 4 by the operation of the movable iron piece 9, the latter operation is performed after the former operation as in the conventional case. The cut-off time can be significantly shortened compared to the case where this was done. Furthermore, since the gap X between the movable iron core 11 and the movable contact 14 is minute, the distance over which the former moves the latter when they engage is relatively expanded. Since the forced separation distance is expanded, the breaking performance can be greatly improved.

(Effects of the Invention) As explained above, according to the overcurrent detection device of the present invention, when an overcurrent is applied, the movable contact can be opened independently and simultaneously with the release of the link mechanism. , it is possible to provide a circuit breaker with high breaking performance in which the breaking time is significantly shortened and the forced opening distance is sufficiently expanded.

[Brief explanation of the drawing]

1 to 5 are diagrams showing one embodiment of the overcurrent detection device according to the present invention, respectively, in which FIG. 1 is a side view showing a closed state, FIG. 2 is a schematic diagram thereof, and FIG. 3 is a cut-off state. 4 is a schematic diagram thereof, FIG. 5 is a side view showing a trip state, and FIG. 6 is a side view showing a conventional overcurrent detection device in a closed state. 1...Base, 2...Power supply Ill@child, 3...
Load side terminal, 4... Link mechanism, 5... Handle,
6... Bimetal, 7... Thermal type tripping mechanism, 8
... Electromagnetic coil, 9 ... Flexible iron piece, 1o ... Fixed iron core, 11 ... Movable iron core, 11a ... Outer shaft, 11b
...knob, 12...electromagnetic type removal mechanism, 13...
- Fixed contact, 14... Movable contact, 15... Arc extinguisher, 16... Main spring, 17... Trip plate.

Claims (1)

[Scope of Claims] A latch mechanism that is released by the action of an electromagnetic coil that is excited when an overcurrent is applied, a link mechanism that moves a movable contact from a closed position to a cutoff position by releasing this latch mechanism, and the electromagnetic coil. a movable iron core that moves due to the excitation of the
An overcurrent detection device for a circuit breaker comprising a movable contact that engages with the movable core and is forcibly separated from the fixed contact as the movable core moves, wherein the electromagnetic coil includes a fixed core and a movable core. A movable iron piece is provided between the fixed core and the latch mechanism to release the latch mechanism by being attracted to the fixed core, and a minute gap is provided between the engaging portion of the movable core and the movable contact. An overcurrent detection device for a circuit breaker, characterized in that: