JPH0226326B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to circuits and disconnectors,
In particular, the present invention relates to a circuit breaker with improved current-limiting performance during a break.

[Conventional technology]

Figures 8 to 13 are, for example,
FIG. 8 is a plan view showing one conventional example, FIG. 9 is a sectional view taken along the line - in FIG. 8, and FIG. Figures 8 and 9 are schematic explanatory diagrams of the behavior of metal particles in circuit breakers, Figure 11 is a partial longitudinal sectional view showing another conventional example, and Figures 12 and 13 are FIG. 3 is a perspective view showing a pressure reflector attached to the fixed conductor and the movable conductor shown in the figure.

In FIGS. 8 and 9, the enclosure 1 is made of an insulator, forms the outer frame of the opening/closing device, and is provided with a discharge port 101. The fixed contact 2 includes a fixed conductor 201 fixed to the enclosure 1 and a fixed contact 202 attached to one end of the fixed conductor 201.
It is composed of. The movable contact 3 opens and closes with respect to the fixed contact 2, and includes a movable conductor 301 that opens and closes with respect to the fixed conductor 201, and a movable conductor 301 that is attached to one end of the movable conductor 301 opposite to the fixed contact 202. It is composed of a contact point 302. The operating mechanism section 4 operates to open and close the movable contact 3. The arc extinguishing plate 5 extinguishes the arc that occurs when the movable contact 302 separates from the fixed contact 202. The pressure reflectors 6 and 7 are each made of the above-mentioned high resistance material, and each has a fixed contact 20.
2. Move the fixed conductors 20 so that the movable contacts 302 protrude and face the arc A.
1. Attached to the movable conductor 301.

Now, when the movable contact 302 and the fixed contact 202 are closed, the current flows from the fixed conductor 201 to the fixed contact 2.
02→movable contact 302→movable conductor 301, the current flows from the current side to the load side. In this state, when a large current such as a short-circuit current flows through this circuit, the operating mechanism section 4 operates to move the movable contact 302 to the fixed contact 2.
Release from 02. At this time, an arc A is generated between the fixed contact 202 and the movable contact 302. In this arc A, as shown in Fig. 10,
The metal particles are reflected by the pressure reflectors 6 and 7,
The arc space becomes under high pressure, so that the arc is effectively cooled and extinguished.

In FIG. 10, a pair of conductors 8 and 9 are a pair of metal cylindrical general conductors facing each other, and conductor 8 is an anode, and conductor 9 is a cathode.
Further, the X planes of each of the conductors 8 and 9 are opposing surfaces that become contact surfaces when the conductors 8 and 9 come into contact, and the Y planes of each of the conductors 8 and 9 are electrical The figure shows the conductor surface which is the contact surface. Moreover, the pressure reflectors 6 and 7 are attached to the conductors 8 and 9 facing the arc A so that the X planes, which are the opposing surfaces of the conductors 8 and 9, respectively, protrude. Of course X
Even if the surface is made of a contact member, the behavior of the metal particles is exactly the same. That is, the pressure values in the spaces Q and Q cannot be higher than the pressure value in the space of the arc A itself, but at least they are overwhelmingly higher than in the case where the pressure reflectors 6 and 7 are not provided. Show value. Therefore, the surrounding spaces Q, Q with a considerably high pressure generated by the pressure reflectors 6, 7
gives a force that suppresses the expansion of the space of arc A, "squeezing" arc A into a narrow space. In other words, the flow rates m, m'o, o' of metal particles a, c, etc. emitted from the X plane, which is the opposing surface, are squeezed into the arc space and confined. Therefore, the metal particles a and c emitted from the X plane are effectively injected into the arc space. As a result, the large amount of effectively injected metal particles a, c removes a large amount of energy from the arc space, which is incomparable with conventional devices, and thus significantly cools the arc space. Therefore, the resistivity ρ, that is, the arc resistance R, is significantly increased, and the arc voltage is significantly increased.

Furthermore, the pressure reflectors 6 and 7 are
If it is installed near the contact surface of the fixed contact 202 and the movable contact 302 as shown in FIG. 9 and FIG. 9, that is, near the periphery of the This prevents A from moving and also limits the size of the legs of arc A. Therefore, the generation of the metal particles a, c can be concentrated on the X plane, and the arc cross-sectional area S can also be reduced, so that the effective injection of the metal particles a, c into the arc space can be further promoted. Therefore, cooling of the arc space, increase in arc resistivity ρ, and increase in arc resistance R can be further promoted, and the arc voltage can be further increased.

In FIGS. 11 to 13, the same parts as in FIG. 9 are designated by the same reference numerals. The pressure reflectors 6 and 7 have a fixed contact 202 and a movable contact 3, respectively.
02 to the arc extinguishing plate 5 direction, each fixed conductor 20
1. Straight grooves 601 and 701 are provided that expose the movable conductor 301 and have a width wider than that of the fixed contact 202 and the movable contact 302.

Next, this operation will be explained. Now, the movable contact 302
When the movable contact 30 opens from the fixed contact 202, the movable contact 30
An arc A is generated between the fixed contact 202 and the fixed contact 202. Since this arc A is attracted by the arc extinguishing plate 5 made of magnetic material, the legs of the arc A are connected to the grooves 601 and 701.
The arc A travels in a straight line in the direction of the arc extinguishing plate 5, and as shown in FIG. 8, the arc A expands and the arc voltage increases, and at the same time, the arc A directly touches the arc extinguishing plate 5 and is rapidly divided and cooled. Also in this case, the grooves 601, 70
1 is wider than the width of the fixed contact 202 and the movable contact 302, the grooves 601 and 70 of the legs of the arc A
After commutation into 1, the cross-sectional area is large and the arc resistance is small. Therefore, even if the circuit current is large, the legs of the arc A easily commutate within the grooves 601 and 701, and the arc A is rapidly divided and cooled.
Furthermore, since the legs of the arc A travel within the grooves 601 and 701, wear and tear on the fixed contact 202 and the movable contact 302 can be reduced.

[Problem that the invention seeks to solve]

In the conventional circuit breakers and disconnectors as described above, the pressure reflectors 6 and 7 are made of high resistance materials such as copper nickel, copper manganese, iron carbon, iron nickel, iron chromium, iron, etc. with a specific resistance of 10 ^-5 to 10. Since the pressure reflectors 6 and 7 are made of high-resistance metal at the ^-4 Ω・cm level, they have no electrical insulation, and arcs that occur during short circuits can cause arcs to touch their surfaces. There was a problem that it was not possible to improve the current limiting performance when the current was interrupted.

This invention was made to solve this problem by providing an insulating material made of heat-resistant synthetic resin powder containing inorganic fine particles that generate arc-extinguishing gas around at least the contact points of the conductor. , metal particles can be forcibly injected into the arc space,
The purpose of the present invention is to obtain a circuit breaker that can improve current-limiting performance when the breaker breaks.

[Means for solving problems]

The circuit breakers and disconnectors according to the present invention are provided with an insulating material made of heat-resistant synthetic resin powder containing inorganic fine particles that generate arc-extinguishing gas around at least the contacts of the conductor.

[Effect]

In this invention, the heat-resistant synthetic resin powder becomes a gaseous body due to the internal oxidation mechanism of the inorganic fine particles in the insulating material when shriveling occurs, and the cooling effect of the arc-extinguishing gas generated from the inorganic fine particles or the liberated moisture causes The arc-extinguishing effect is further strengthened.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings. FIG. 1 is a plan sectional view showing one embodiment of a circuit breaker according to the present invention, FIG. 2 is a side sectional view taken along the line - of FIG. 1, and FIG. FIG. 3 is a schematic explanatory diagram of the behavior of metal particles in the circuit and disconnector shown in the figure. In the drawings, 1 to 5 and A are the same as those in FIGS. 8 to 10, so explanations thereof will be omitted. 6A and 7A are insulating materials attached in the form of plates to the opposite surfaces of the fixed conductor 201 and the movable conductor 301, respectively, so as to face the arc A around the entire circumference of each contact 202 and 302, and are made of insulating material such as hydrated alumina. It is composed of an insulating layer made of heat-resistant synthetic resin powder containing inorganic fine particles that generate arc gas.

Now, when the movable contact 302 and the fixed contact 202 are closed, the current flows from the fixed conductor 201 to the fixed contact 2.
02→movable contact 302→movable conductor 301 from the power supply side to the load side. When a large current such as a short-circuit current flows through this circuit in this state, the operating mechanism section 4 operates to separate the movable contact 302 from the fixed contact 202. At this time, an arc A is generated between the fixed contact 202 and the movable contact 302. In this arc A, as shown in FIG. 3, metal particles are reflected by the insulating materials 6A and 7A, and the arc space becomes high pressure, so that the arc is effectively cooled and extinguished.

When the insulating materials 6A, 7A are provided around the entire circumference of each contact 202, 302 in this way, each contact 202, 302
The metal particles behave in the following manner, which will be explained below with reference to FIG.

That is, the pressure value in the space Q cannot be higher than the pressure value in the space of the arc A itself, but at least it shows an overwhelmingly higher value than in the case where the insulating materials 6A and 7A are not provided. Therefore, the surrounding space Q, which has a considerably high pressure created by the insulating materials 6A and 7A, provides a force that suppresses the expansion of the space of the arc A, and "squeezes" the arc A into a narrow space. In other words, the streamlines m, o of metal particles a, c, etc. emitted from the X plane, which is the opposing surface, are squeezed into the arc space and confined.
Therefore, the metal particles a and c emitted from the X plane are effectively injected into the arc space. As a result, the large amount of effectively injected metal particles a, c removes a large amount of energy from the arc space, which is incomparable with conventional devices, and thus significantly cools the arc space. Therefore, the resistivity ρ, that is, the arc resistance R, is significantly increased, and the arc voltage is significantly increased.

The insulating materials 6A and 7A in the above embodiments are, for example, made by adding hydrated alumina, aluminum hydroxide, etc. to heat-resistant synthetic resin powder made of a matrix of epoxy resin, polyimide resin, polyester resin, hismaleimide triazine resin, etc. In this way, an inorganic material with excellent arc-extinguishing properties is mixed or formed on the surface layer.

By using a synthetic resin composition composed of such a substance as the insulating materials 6A and 7A, the heat-resistant synthetic resin becomes hydrocarbon gas, water vapor, etc. due to the internal oxidation mechanism of the hydrated alumina added when a large current is applied. Since it is a gas mainly composed of carbide and does not cause carbonization on the surface or inside, it becomes difficult to form an electric path due to carbide. Further, the arc-extinguishing action of the arc-extinguishing device is further strengthened by the cooling action of the arc-extinguishing gas generated from the arc-extinguishing substance such as hydrated alumina used for the insulating materials 6A and 7A, or the moisture released. In this case, the amount of hydrated alumina added to the insulating materials 6A and 7A is suitably in the range of 20 to 60 weight percent from the viewpoint of adjusting the amount of gas generated during processing of the insulation coating. Furthermore, since the legs of arc A are difficult to expand to the Y surface, the contact points 202 and 302 are generally provided on this Y surface.
This has the advantage that it becomes difficult for the arc foot to directly touch the junction between the conductor 201 and the conductor 201, 301, and as a result, there is no risk of the contact falling off.

FIGS. 4 and 5 show other embodiments of the insulating materials 6A and 7A. In this embodiment, the conductors 201 and 301 are covered by taping or coating to form insulating materials 6B and 7B. Grooves 601, 701 are formed in parts of the insulating materials 6B, 7B to expose the surfaces of the conductors 201, 301 in the direction from the contacts 202, 302 toward the arc-extinguishing plate 5, as shown in FIGS. 6 and 7. If provided, the legs of the arc A run in the grooves 601, 701 and are cooled by touching the arc extinguishing plate 5, thereby further improving the arc cutting performance. Note that this groove may be provided in one of the insulating materials 6B, 7B, or several grooves may be provided. Furthermore, this groove may be provided in the insulating materials 6A and 7A shown in FIGS. 1 and 2.

〔Effect of the invention〕

As described above, according to the present invention, metal particles can be forcibly injected into the arc space by providing an insulating material on the conductor so as to surround the contact, so it is possible to forcibly inject metal particles into the arc space. It has the effect of providing excellent arc resistance and safe circuit connection and disconnection.

[Brief explanation of drawings]

FIG. 1 is a plan sectional view showing an embodiment of the circuit breaker according to the present invention, FIG. 2 is a side sectional view taken along the line - in FIG. 1, and FIG. A schematic explanatory diagram of the behavior of metal particles in circuit breakers and disconnectors, Fig. 4 is a side view showing another example of the insulating material, Fig. 5 is a bottom view of Fig. 4, and Fig. 6 is a diagram showing the behavior of the insulating material. 7 is a bottom view of FIG. 6, FIG. 8 is a plan view of a conventional example, FIG. 9 is a sectional view taken along the line - of FIG. 8, and FIG. 10 is a side view showing another embodiment. is a schematic explanatory diagram of the behavior of metal particles in the circuit breakers shown in FIGS. 8 and 9, FIG. 11 is a partial longitudinal sectional view showing another conventional example, and FIGS. 12 and 13 are 1
2 is a perspective view showing a pressure reflector attached to the fixed conductor and the movable conductor shown in FIG. 1. FIG. In the figure, 2 is a fixed contact, 201 is a fixed conductor, 202 is a fixed contact, 3 is a movable contact, 301
is a movable conductor, 302 is a movable contact, 6A, 6B, 7
A and 7B are insulating materials. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. In a circuit or disconnector having at least one pair of electrical contacts that open and close and are constituted by a conductor and a contact, an arc-extinguishing gas is provided around at least the contact of the conductor. 1. A circuit switch or breaker characterized by being provided with an insulating material made of heat-resistant synthetic resin powder containing inorganic fine particles that generate . 2. The circuit breaker or circuit breaker according to claim 1, characterized in that the conductor is coated with an insulating material.