JP3383137B2 - Circuit breaker - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker or an earth leakage breaker in which a trip device, an opening / closing mechanism, a terminal device and the like are housed in a housing made of a synthetic resin material.

[0002]

2. Description of the Related Art FIG. 8 is a side view showing a conventional molded case type circuit breaker. In the figure, 1 is a movable contactor, 2 is a movable contact fixed to one end of the movable contactor 3,
Is a fixed contact which comes into contact with the movable contact 2 by the rotation of the movable contact 1, 4 is a fixed contact to which the fixed contact 3 is fixed, 5
Is a power source side terminal portion connected to one end of the fixed contactor 4. 6 is an arc extinguishing chamber, 6a is an arc extinguishing plate for cooling and extinguishing the arc generated between the movable contact 2 and the fixed contact 3, and 6a.
Reference numeral b is an arc-extinguishing side plate that holds the arc-extinguishing plate 6a. Reference numeral 7 is an opening / closing mechanism for rotating the movable contact 1, 8 is a handle for manually operating the opening / closing mechanism 7, 9 is a tripping device, and 10 is a load side terminal. Reference numeral 101 denotes a housing that houses the above-described components, and includes a cover 11 and a base 12 formed of a synthetic resin material. 13 is an exhaust hole,
The housing 101 is provided near the power supply side terminal portion 5.

Next, the operation will be described. First, the power source side terminal portion 5 is connected to the power source and the load side terminal portion 10 is connected to the load. When the handle 8 is operated, the movable contact 2 and the fixed contact 3 are brought into contact with or separated from each other by the rotation of the movable contactor via the opening / closing mechanism 7. By this contact or separation, power is supplied to or cut off from the load. In addition,
In the contact state, the movable contact 2 is pressed against the fixed contact 3 with a predetermined contact pressure in order to ensure reliability of energization. In this state, if an overcurrent occurs in the load side circuit, the trip device 9 detects this overcurrent and opens / closes the opening / closing mechanism section 7.
The movable contact 2 is separated from the fixed contact 3 by the rotation of the movable contactor 1 via. When the movable contact 2 is separated from the fixed contact 3, an arc is generated between the contacts 2 and 3. The arc voltage for generating this arc increases as the distance that the movable contact 2 separates from the fixed contact 3 increases, and further increases when the arc is attracted by the magnetic force toward the arc extinguishing plate 6 and extends. To do. The extended arc is extinguished by the arc extinguishing plate 6 and the interruption is completed. In this case, when a large current such as a short-circuit current is cut off, a large amount of energy may be generated by the arc within a short time, that is, within a few milliseconds.
This large amount of energy rapidly increases in temperature in the housing 101,
High-pressure gas (hereinafter referred to as arc gas) becomes exhaust hole 1
3, but most of the components inside the housing 101 are exposed to this arc gas.

[0004]

In the conventional circuit breaker as described above, when a large current such as a short circuit current is cut off,
The arc gas of large energy generated by the generated arc,
The movable contact 1, the fixed contact 4, its contacts 2, 3 or the metal material such as the arc extinguishing plate 6 is melted, and the synthetic resin material such as the cover 11, the base 12, the arc extinguishing side plate 6b is decomposed. Moreover, since the pressure inside the circuit breaker rapidly rises at the same time as the arc is generated, the free carbon generated from these metal vapors, droplets or synthetic resin material diffuses to the inside of the casing 101. This may be vapor-deposited, adhered, or accumulated inside the housing 101, and the insulation resistance value in the circuit breaker may be greatly reduced partially. Further, if there is a communication hole formed in the partition wall between adjacent poles inside the housing 101, dielectric breakdown between the poles may occur through the communication hole as a path. Further, if the visibility in the direction of the tripping device is large from the space in which the arc is generated, the melted material due to the arc easily passes through, and the insulation resistance value between the power source side terminal portion 5 and the load side terminal portion 10 after interruption is also high. May be significantly reduced. The decrease of these insulation resistance values is slight if the opening and closing of the normal current value has no effect on insulation, but as the current value to be interrupted increases, the decrease becomes more remarkable as the number of interruptions increases, A short circuit accident may occur inside the breaker.

The present invention has been made in order to solve the above problems, and in particular, has a high breaking capacity and safety by suppressing insulation deterioration after breaking a large current. The purpose is to obtain a circuit breaker with high performance.

[0006]

In a circuit breaker according to the present invention, a circuit breaker in which a trip device, an opening / closing mechanism portion, a terminal device, and the like are housed in a housing formed of a synthetic resin material is adjacent to each other. The inner circumference of the communication hole formed in the partition wall between the electrodes and the main circuit conductor of the above-mentioned housing.
A rough surface member made of a foam material made of an insulating material is installed on the inner circumference of the portion formed on the.

Further, in a circuit breaker in which a trip device, an opening / closing mechanism portion, a terminal device, etc. are housed in a casing made of a synthetic resin material, an insulating material foam is formed on the outer surface of the trip device or the opening / closing mechanism portion. The rough surface member formed of the material is installed.

[0008] Furthermore, the rough surface member is one that is configured to be supported affixed to a support member formed of an insulating sheet.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. FIG. 1 shows a multipole circuit breaker according to an embodiment of the present invention. In the figure, reference numeral 101 denotes a housing that houses a trip device, an opening / closing mechanism portion, a terminal device (not shown), and the like, and includes a cover 11 and a base 12 formed of a synthetic resin material. 11a and 12a are partition walls formed between adjacent poles, 14 is a trip bar of the trip device, 11b is a communication hole formed in the partition wall 11a, and the trip bar 14 is connected to the trip device of each pole. It is what makes me. Reference numeral 15 denotes a rough surface member, and in the case of this embodiment, as shown in FIGS.
Is attached to the inner periphery of the communication hole 11b formed in the partition wall 11a, and the rough surface member 15b is attached to the edge of the partition wall 12a on the base 12 side. The rough surface members 15a and 15b are formed of a foam material made of an insulating material, for example, a foam material having a base material of polyethylene resin, polystyrene resin, polypropylene resin, or silicon resin,
It is formed in a plate shape having elasticity such that it can be easily bent. Although foamed rubber having chloroprene rubber as a base material is used depending on the portion to be installed, among various foamed materials, a foamed material having a silicon resin as a base material is most suitable.
The bubble volume fraction of the foam material varies depending on the foam material or the place of installation, but 3% to 80% can be used.

In the circuit breaker constructed as described above, when a large current such as a short-circuit current flows, the trip device detects it and rotates the trip bar 14 to trip the opening / closing mechanism section. The arc gas of a large amount of energy generated at the time of this trip fills the casing 101 for each pole, but if there is a pressure difference between the poles, the arc gas will pass through the communication hole 11b formed in the partition wall 11a to the other pole. It may flow. At this time, since the communication hole 11b has a small clearance dimension with the trip bar 14 due to the installation of the rough surface member 15, the amount of arc gas flowing into the communication hole 11b is suppressed. Even if the melt or carbon adheres and deposits by flowing in, the creepage distance between the adjacent poles is substantially increased by the rough surface member 15, so the insulation deterioration between the poles is small.
The same effect can be obtained by installing the rough surface member 15 as shown in FIGS. 3 (a) and 3 (b). That is, the rough surface member 15a
Is attached to the inlet surface of the communication hole 11b formed in the partition wall 11a, and the rough surface member 15b is attached to the side surface of the partition wall 12a of the base 12 facing the communication hole 11b. In this case, the rough surface members 15a and 15b may be attached to the surface on the opposite side of the drawing.

Embodiment 2. In the first embodiment, the rough surface member 15 is provided on the inner circumference of the communication hole 11b formed in the partition wall 11a, but the rough surface member 15 is provided at the intermediate portion for each pole. Good. That is, FIG. 4 is installed in the portion of the movable contactor 1, and in the figure, the cover 11 and the base 12 show only a part broken in the vertical direction. On the side of the movable contact 2 of the movable contact 1, there are a fixed contact 4, an arc extinguishing chamber, a power source side terminal portion, and the like. Further, on the opposite side (left side in the figure), there are an opening / closing mechanism section, a trip device, a load side terminal section, etc., but they are not shown. The rough surface member 15a is attached to the inner periphery of the cover 11 in a band shape, and the rough surface member 15b is attached to the inner periphery of the base 12 in a band shape at a position corresponding to the rough surface member 15a. With the above structure, even if the arc gas generated at the movable contact 2 flows into the opening / closing mechanism or the trip device side, the cover 11
Also, there is little deterioration of insulation inside the base 12, and the problem of current leakage between the power supply side terminal portion and the load side terminal portion can be solved. Note that the rough surface member 15a or 15b can be easily attached at low cost by providing an adhesive layer that can be adhered to the cover 11 and the base 12 on one surface of the rough surface member.

Embodiment 3. Further, in the above-described first and second embodiments, the case where the rough surface member 15 is installed on the inner circumference of the housing 101 is shown.
It may be installed on the outer surface of the component housed in. That is, FIG.
6 and FIG. 6 show the rough surface member 15 installed in the zero-phase current transformer portion of the earth leakage breaker. In the figure, 9 is a trip device, 10 is a load side terminal portion, 11 is a cover, 12 is a base, 14 is a trip bar, and 16 is a zero-phase current transformer for detecting electric leakage. Reference numeral 17 is a primary conductor of the main circuit, and the primary conductors 17a, 17b, 17c of the respective poles are locally approached and concentrated to pass through the zero-phase current transformer 16. 9a, 9b,
Reference numeral 9c is a trip device for each pole. In this way, the primary conductors 17a, 17b, 17c of each pole are closely approached and concentrated, and various parts are densely packed, so that communication holes or spaces communicating between the poles are formed at various places. The rough surface member 15 in this configuration is installed in the same manner as that shown in the first and second embodiments. That is, 15c is a rough surface member installed on the outer periphery of the zero-phase current transformer 16, and the rough surface member 15c divided into several pieces is attached. Reference numeral 15d is a rough surface member installed between the outer periphery of the case 19 accommodating the electronic circuit portion 18 and the cover 11. The rough surface member has a large elasticity even if the bubble volume fraction is small, such as foamed rubber made of chloroprene rubber. May be suitable. In addition to the above, the primary conductor 1
If there is a space in the vicinity of 7a, 17b, 17c, between the trip device 9 and the zero-phase current transformer 16, a rough surface member having an appropriate size is installed corresponding to the space. For example, as in the case of the rough surface member 15e, the rough surface member 15d may be placed so as to be superposed. In addition, 20 is a rough surface member to which a supporting member is attached, which will be described in the fourth embodiment.

Embodiment 4. In the configurations shown in FIGS. 5 and 6, reference numeral 20 denotes a rough surface member which is affixed to and supported by a support member, and is inserted and installed in the gap between the trip device 9 and the zero-phase current transformer 16, for example.
The rough surface member 20 is formed as shown in FIG.
That is, 20a is a supporting member, which is formed of a synthetic resin sheet or an insulating thin plate such as fish paper. Reference numerals 15f, 15g, and 15h denote rough surface members, which are bent and attached for installation on both surfaces of the support member 20a. By inserting this rough surface member 20 into the gap, the passage of the arc gas is suppressed, and even if it passes, the creepage distance is substantially increased, so that the insulation deterioration is reduced. Like the rough surface member according to this embodiment, the configuration in which the rough surface member is attached to the insulating thin plate and installed can also be applied to the rough surface member 15 in the first, second or third embodiment.

[0014]

Since the present invention is constructed as described above, it has the following effects.

By installing a rough surface member formed of a foam material made of an insulating material that penetrates through the inner periphery of the communication hole formed in the partition wall between adjacent poles, insulation between the poles is maintained even after a large current is cut off. It is possible to obtain a safe circuit breaker with high breaking performance that suppresses the deterioration of performance.

Further, among the housing, the inner periphery of the housing portion is formed so as to surround the main circuit conductor, by providing the roughened surface member formed of an insulating material made of foamed material, a large current It is possible to prevent the dielectric breakdown between the opened terminals after breaking, and also to divide the flow of the arc gas, so that a circuit breaker with stable operation performance can be obtained.

Furthermore, by installing the trip unit or roughened member formed of an insulating material made of foamed material outside <br/> surface of the opening and closing Organization, suppressing a decrease in insulation performance between adjacent components , High circuit breaking performance and safe circuit breaker can be obtained.

[0018] Furthermore, the rough surface member, der being supported by vignetting affixed to a support member formed of an insulating sheet
Therefore, the assemblability is improved, and since it can be applied to a complicated shape portion, a highly safe circuit breaker with enhanced insulation performance can be obtained.

[Brief description of drawings]

FIG. 1 is a side sectional view of a circuit breaker according to a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a main part of the first embodiment .

FIG. 3 is an enlarged perspective view of a main part of the first embodiment .

FIG. 4 is an enlarged perspective view of a main part of a circuit breaker according to a second embodiment of the present invention .

FIG. 5 is a side sectional view showing a part of the circuit breaker according to the third and fourth embodiments of the present invention .

FIG. 6 is a plan view showing a part of the circuit breaker according to the third and fourth embodiments of the present invention .

7 is a perspective view showing the structure of a rough surface member.

FIG. 8 is a side sectional view of a conventional circuit breaker.

[Explanation of symbols]

5 power supply side terminal part, 7 opening / closing mechanism part, 9 tripping device,
10 load side terminal portion, 11 cover, 11a partition wall, 1
1b communication hole, 12 base, 15, 20 rough surface member,
101 housing.

Continuation of the front page (56) Reference JP 58-181229 (JP, A) JP 59-75515 (JP, A) JP 58-181236 (JP, A) JP 58-181250 (JP , A) Actual development 60-57039 (JP, U) Actual development 59-69468 (JP, U) Actual development 59-86617 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) H01H 73/06 H01H 71/02

Claims (3)

(57) [Claims] 1. A circuit breaker in which a trip device, an opening / closing mechanism, a terminal device, etc. are housed in a housing made of a synthetic resin material, and an inner periphery of a communication hole formed in a partition wall between adjacent poles. And of the above housing, so as to surround the main circuit conductor.
A circuit breaker characterized in that a rough surface member formed of a foam material made of an insulating material is installed on the inner periphery of the housing in the portion formed in. 2. A circuit breaker in which a trip device, an opening / closing mechanism part, a terminal device, etc. are housed in a housing made of a synthetic resin material, the outer surface of the trip device or the opening / closing mechanism part. A circuit breaker in which a rough surface member made of a foam material made of an insulating material is installed in the. Wherein said roughened surface member, according to claim 1 or circuit breaker of claim 2 wherein, characterized in that it is supported affixed to a support member formed of an insulating sheet.