JPS6074310A - 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 [Technical Field of the Invention] The present invention relates to a circuit breaker for opening and closing an electric circuit, and more particularly to a circuit breaker equipped with a current-carrying contact, an arcing contact, and an arc-blowing coil.

[Technical background of the invention and its problems]

Generally, a circuit breaker uses a fixed contact and a movable contact to open and close the electrical circuit to be opened and closed, but an arc blowing coil that generates a magnetic driving force is used to extend and extinguish the arc generated at the opening 8). In addition, since the contacts are damaged by arcing, two sets of contacts are provided, one for carrying and one for arcing and one for arc generation and interruption.

The conventional circuit breaker will be explained with reference to FIG.

It is equipped with a fixed frame 1 and a movable frame 2, each of which has conductivity, and fixed and movable contacts 3A, sB for arcing and fixed and movable contacts 4A for energization are provided at opposing positions of both frames 1.2, respectively. , 4B are attached with bolts so that they may come into contact or be separated by the rotation of the movable frame 2, and an arc blowing coil 5 is provided on the fixed frame 1 side to connect the fixed side and the movable side. is connected to the electrical circuit to be switched. When the movable side is in contact with the fixed side as shown in Figure 1.

Current flows through each set for arcing and energizing, blowing out the coil 5.
'fr: The circuit is opened through
, 4B are separated first, and then the arc contacts 3A and 3B are moved later by the Wig mechanism 6, and the arc contacts 3A and 3B are separated, and the arc generated at this time is extended toward the arc chute 7 side by the magnetic driving force of the blowing coil 5. This erases the current in the electrical circuit to be opened or closed.

By the way, in the circuit breaker of the conventional configuration mentioned above.

Since the current is always stagnant when energized to the blowing coil 5 for magnetically driving the arc during opening, there are various problems due to not only wasted power consumption but also heat generation.

In other words, 2. Normally, steel is used for the blowout coil 5, but
The resistance value cannot be reduced to zero at room temperature, and for this reason, the current rating of circuit breakers varies from several amps (amperes) to several thousand.
As an example, in the case of a rated current of 5 QOA, the resistance value of the blowing coil 5 is about o, oooi Ω, and the heat generation amount is about 36 W, and the surface temperature of the blowing coil 5 is io o'c.
.

will be able to exceed. Therefore, the heat generated by the blowing coil 5 not only wastes electricity and power, but also puts a thermal load on the surrounding materials and causes them to deteriorate. There were many problems, including the need for protective measures to prevent the adverse effects of heat on the body.

In order to reduce the amount of heat generated by the blowing coil 5 itself, there is an idea of using a coil material with a low resistance value 9 or increasing the cross-sectional area of the coil to lower the resistance value, but this is expensive and increases the coil space and weight. There is a problem with this.

In addition, there is an improvement method in which the blowing coil is placed in a separate circuit, such as a small blowing coil that generates less heat by being excited by the low voltage flow of the control circuit, or a permanent magnet. If the circuit changes, there is a risk of driving the arc in the opposite direction of the arc chute 7.

On the other hand, as a result of the increasing use of diode control devices and variable frequency control as control methods for rotating machines such as vehicles, circuit breakers are not only capable of interrupting large currents flowing through rotating machines. There are increasing demands for the responsibility of interrupting small currents (such as leakage currents in semiconductor control devices) during startup and shutdown. That small current? When breaking, the arc current is small, but the magnetic driving force of the blowing coil is also small, so the arc is not extinguished properly and persists between the contacts, causing magnetic ionization and deteriorating the surrounding insulation, resulting in short circuits and damage to parts. This may cause damage. In addition, in the case of such a small current interruption, if the current interruption is performed after the flow direction is reversed, the arc will not arc shoot because sufficient magnetic flux will not be obtained to cancel out the residual magnetic flux of the magnetic material that is the medium of the blowing magnetic flux. There is a danger of being driven in the opposite direction to 7. In order to eliminate these various problems, it is possible to significantly increase the number of turns of the moving base blowing coil that cuts off small currents as described in mJ, but increasing the number of turns of the coil, which has a limited thickness, will cause problems in terms of space and weight. Not only that, but the problem of heat generation also occurs. There is also a method of attaching a secondary blowing coil inside the arc chute, but this is effective for interrupting large currents, but it is effective for interrupting small currents as mentioned above because the magnetic driving force of the primary blowing coil is originally weak. does not function.

Tsukuki: With conventional circuit breakers, whether for large current or small current, it is important to eliminate wasteful power consumption and reduce heat generation due to changes in cost, space, weight, box, and flow direction. Considering these factors, there were many problems, and it was quite difficult to realize a circuit breaker with low heat generation.

[Purpose of the invention]

This invention was made in view of the above circumstances.

When the pole is closed, electricity is applied without going through the blowout coil.

There is no wasted frost, power consumption, or heat generation in the blow-out coil.

Only when arc blowing force is required during opening operation, circuit current flows to the blowing coil to ensure reliable interruption.Moreover, since the blowing coil is not energized during closing, the heat of the blowing coil is reduced. The purpose is to significantly reduce the load so that less expensive coil materials can be used.

[Summary of the invention]

In the circuit breaker of the present invention, a fixed contact for energizing and a fixed contact for earthing are provided on a fixed frame in a state where they are electrically insulated from each other, and the fixed contact for energizing is connected to an electrical circuit to be opened or closed. Directly, while in parallel, the arc fixed contact is connected via a blowing coil, and when the pole is closed, circuit 1 current flows only from the energizing contact side with low resistance, without going through the blowing coil. After the energizing contact is separated by the opening operation, a circuit current flows through the arcing contact to the blowing coil, and a magnetic driving force necessary and sufficient for arc blowing is generated in the correct direction.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 2 to 4. Components in the drawings that have the same configuration as those in FIG. 1 are designated by the same reference numerals at the same locations in the drawings to simplify the explanation. Here, the fixed frame l is made of a conductive metal material as in the conventional case, and in order to electrically insulate the arc fixed contact 3A and the energizing fixed contact 4A from each other, the energizing fixed contact 4A is connected to the fixed frame J. An L-shaped insulating plate 8 is interposed between them, and the fastening is fixed by an insulating 7Ir bolt 9. Furthermore, the arc fixed contact 3A is connected to the terminal 11 of the circuit, and in parallel with this, the arc fixed contact 3A is connected to one end of the blowing coil 5C via the b1 constant frame 1. The other end is connected to the 911i terminal 11 of the electrical circuit to be opened and closed, which has the same potential as the energizing fixed contact 4A.

Nao, for example, in a circuit breaker of about 1500V-600A,
Is the potential at both ends of the blowing coil 5C 1? Insulating plate 8 and insulating bolt 9 may have low insulating performance.

To explain the operation of the circuit breaker with the above-mentioned configuration, first of all, when the circuit breaker is completely closed as shown in Figure 2, most of the circuit current flows due to the resistance of the blowing coil 5C, which has a low resistance. Current contact 4A.

4B, and the arc contact 3A, s B side route where the blowing coil 5C is located has 11
It doesn't flow at all. Therefore, the current value of the blowing coil 5C is very low, and hardly any heat is generated.

For example, circuit current I = 60OA, arc contact 3A, 3
The total of the contact resistance ra of B and the contact resistance rc of the current-carrying contacts 4A and 4B is about 25 μΩ.

If the resistance r of the blowing coil is ≠0.0005Ω, the current 11 flowing through the blowing coil 5C is as follows.

=, about 2 7.3 A, and the heat generation of the blowing coil 5C at this time is 0.3
It's only 72W.

In addition, if the resistance value of the blowing coil 5C is increased, the current will be further increased.
The flow of the current decreases and the amount of heat generated can be reduced, but if the amount of heat is as low as mentioned above, there will be no adverse effect on the surroundings, so there is no need for it, and at the time of primary opening (2. Since a capacitance that can withstand current is required, a resistance value of about the above-mentioned value is appropriate.

Next, when the movable frame 2 is driven to perform an opening operation without wiping, first the energizing contacts 4A and 4B are separated as shown in FIG. 3, but the arc contact 3 has a large wipe amount. Man.

3B maintains contact. At this point, the energizing contact 4A,
Since the gap between the arc contacts 4B creates a large resistance, one circuit current flows through the arc contacts 3A, JB and the blowing coil 5C.

Incidentally, at this time, since the potential difference between the energizing contacts 4A, 4B is small, no arc occurs.

As the opening operation progresses, the arc contacts sA and 3B are also completely separated as shown in FIG.

An arc will occur during that time, but has that arc already passed?
The magnetic driving force of the blowout coil 5C in the d state leads it to the arc chute 7 and erases it, as in the conventional case, thereby completing the interruption.

In addition, even when the direction of the circuit current changes forward or reverse due to the vehicle's current flow or regeneration, such as in a DC circuit breaker used in a vehicle, the blowing coil that is excited by the current in its (b) path The relationship between the magnetic flux direction of 5C and the current direction of the arc never changes, and the arc is always driven toward the arc chute 7 side.

Furthermore, if the circuit breaker has the above-mentioned configuration, the blowing coil 5
The current flowing through C is very small when the circuit is closed (usually within 0.1 seconds), and the rated current flows only during the opening operation (usually within 0.1 seconds) and during reverse closing, so the blowing coil 5C The heat generation h1 is extremely small both in absolute value and in terms of time, and it is possible to make the coil itself from an inexpensive material with a slightly higher υ resistance than the conventional one, or to make the coil curve thinner to obtain the required blowing force. Even if the number of turns is increased, there is no problem and it becomes possible to realize a small, lightweight and inexpensive device. Further, since unnecessary heat generation in the blowing coil 5C is eliminated, there is no adverse thermal effect on surrounding materials and other peripheral devices, and the setting and design of these materials is also facilitated. Furthermore, even in the case of small-scale flow interruption, it is possible to create a blowout coil that is small, lightweight, and has a large number of turns, so that the interruption performance can be improved.

Note that the present invention is not limited to the above-mentioned embodiments; for example, in FIG. And insulation? The fixing frame J itself can be made of an insulating material, and the arc fixed contact 3A and the blowing coil 5C can be fastened together with ordinary bolts without using the bolt 9. Wiring may be provided between them.

Moreover, FIGS. 5(a) and 5(b) show modified examples of the arc contact in the circuit breaker of the present invention, in which the arc movable contact sB' has a contact surface with respect to the arc fixed contact 3A. The structure has an insulating part 3C in a part of the
When both contacts are fully inserted as shown in a),
Since the movable contact 3B' is connected to the single contact 3A at the insulating part 3d, no current flows there, and as shown in FIG. 5(b), the p synchronized contact When aB' is tilted, its conductive portion comes into contact with the fixed contact 3A. With this, no current is passed through the blowing coil 5C when the pole is closed, and only during the opening operation, the blowing coil 5C is cut off by moving 8 meters.

〔Effect of the invention〕

Since this invention is made as described above, a circuit current flows through the blowing coil only during the opening operation that requires arc blowing force, and almost no current flows through the blowing coil at other times, so that the heat load on the blowing coil is reduced. It is extremely practical as it can reduce the cost of the coil material, make it smaller in diameter and make it lighter in weight, and can also greatly reduce the amount of heat generated due to wasted knowledge and force consumption, eliminating the negative effects on JJ products. The effect will be great.

[Brief explanation of the drawing]

Figure 1 is a side view showing the schematic configuration of a conventional circuit breaker;
The figure is a side view of a schematic configuration showing one embodiment of the present invention, and FIG.
Figure 47 is also an explanatory diagram of the state when the contact is open, Figure 5 (a)
(b) is a diagram illustrating the operation of a companion example of the arc contactor in the same embodiment. l...Fixed frame, 2...Movable frame, JA・
... Fixed contact for arc, 3B, sB'... Movable contact for 7-ri 1, 3C... Insulation part, 4A... Fixed contact for current, 4B... Movable contact for current, 5,5C...
Blowing coil, 6... Wipe mechanism, 7... Arc chute, 8... Insulating plate, 9... Definitely delt, 10...
・Conductive material, 11...terminal. Elderly person agent Patent attorney Rin Ushiki Hiko Figure 1 Figure 2

Claims (1)

[Scope of Claims] (1) In a circuit breaker comprising a fixed and movable contact for energization, a fixed and movable contact for arc, and an arc blowing coil, the fixed contact for energization and the fixed arc contact The energizing fixed contact is connected directly to the electrical circuit to be opened and closed, while the arcing fixed contact is connected to an arc blowing coil in parallel with the energizing fixed contact. A circuit breaker characterized in that the circuit breaker is configured by being connected through the circuit breaker. (2) The current-carrying fixed contact is fixed to the conductive fixed frame on which the arcing fixed contact is supported, with an insulating plate interposed and an insulating bolt. The circuit breaker according to item 1. (31 A fixed contact for current-carrying has an insulating phase part in part. A patent characterized in that the insulating material part is joined and fixed with bolts to a conductive fixed frame on which the fixed contact for arcing is supported. The circuit breaker according to claim 1. (4+ The circuit breaker according to claim 1, characterized in that the energizing and arcing fixed contacts are each fixed to an insulating fixed frame. (5) The fixed and movable arc contacts are characterized in that at least one of them has an insulating part on a part of the contact surface, allowing complete electrical conduction between the two only when the wipe is activated. A circuit breaker according to any one of claims 1 to 4.