JP2000222994A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage of a case, and also reduce the cross directional dimension by arranging each circuit breaker part, in which the electromagnetic force by the current flowing in both contacts develops the electromagnetic repulsion for resisting the spring pressure, in parallel with three phases, and arranging the circuit breaker part of an intermediate layer while being displaced in a direction for reducing the electromagnetic force of the circuit-breaker part of other phases. SOLUTION: Each movable contact 501 provided under each movable contact carrier 500R, 500S, 500T of three-phase of the RST phase structure pushes each fixed contact 401 of each fixed contact carrier 400R, 400S, 400T. A circuit breaker part, in which the electromagnetic force by the current flowing in both the contacts 501, 401 develops the electromagnetic repulsion force for resisting the spring pressure, is arranged in parallel with the three-phase of the RST phase structure with an equal space. A circuit breaker part of the S phase as an intermediate phase is arranged while being displaced to a position for forming a triangle, and a handle for switching the movable contact is provided over the movable contact carrier 500S. With this structure, cross directional dimension can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is installed in a switchboard or the like, and can cut off a short-circuit current flowing to a load when a short-circuit fault occurs.
This is a circuit breaker related to an arrangement of a breaking portion including a movable contact and a fixed contact of the circuit breaker that can break a circuit even in a normal state.

[0002]

2. Description of the Related Art Circuit breakers are used for transmission and distribution lines and substation buses.
This switch is used to automatically shut off the circuit when a short-circuit fault occurs in equipment or the like, and is used to open and close the circuit in normal times. Circuit breakers are mainly used side by side on switchboards, etc.
Since the installation area increases as the number increases, a narrow and small circuit breaker capable of reducing the installation area is required.

FIGS. 6 and 7 show the structure of a conventional circuit breaker.
The phase circuit breaker will be described. Fixed contact stand 400,
The movable contact stand 500 includes an opening / closing mechanism 600 for opening and closing the movable contact stand 500, a handle 100 for operating the opening / closing mechanism 600 from outside, a cover 200 for accommodating these, and a case 300. The fixed contact stand 400 and the movable contact stand 500 are provided one set for each phase. The fixed contact stand 400 and the movable contact stand 500 are respectively a fixed contact 401 and a movable contact stand 500 provided on the fixed contact stand 400.
And the movable contact 501 provided in the above.

The circuit is opened and closed by connecting and disconnecting the fixed contact 401 and the movable contact 501. The R-phase fixed contact block 400R, the S-phase fixed contact block 400S, and the T-phase fixed contact block 400T of each phase are installed at the same distance from the surface on which the handle 100 is mounted. Movable contact block 500 for each phase
Is also the same as the position of each phase fixed contact block.

[0005] The direction in which the phases are arranged is determined by the handle 10
It is installed at equal intervals in parallel with the plane to which the “0” is attached.
The terminal blocks 450R, 450S, 450T for tightening the electric wires provided on the fixed contact block 500 of each phase are
It is installed at the same distance from the surface where 0 is attached. FIG.
Then, the left side of the figure is the power supply side, and the right side is the load side.

The circuit is normally opened by operating the handle 100, driving the opening / closing mechanism 600, lifting the movable contact base 500, and pulling the movable contact 501 from the fixed contact 401. At this time, the fixed contact 401 and the movable contact 5
01, the magnetic plate drives the cooling plate 70
It is designed to extinguish the arc by leading to 0.

When a short-circuit accident occurs and a short-circuit current flows, the fixed contact 401 of the fixed contact stand 400 and the movable contact stand 5
The movable contact table 500 is instantaneously driven by using the electromagnetic repulsion of the current flowing through the movable contact 501 of the movable contact 501. At the same time, the trip device 110 operates the opening / closing mechanism unit 600 to hold the movable contact table 500 at the open position, and the open is completed. Also in this case, the arc generated between the fixed contact 401 and the movable contact 501 is guided to the cooling plate 700 by magnetic driving to extinguish the arc.

The fixed contact block 400 and the movable contact block 5 of each phase
00 is installed at the same distance from the surface on which the handle 100 is mounted. Furthermore, they are arranged so that the direction in which the phases are arranged is parallel to the surface on which the handle 100 is mounted. In this case, the movable contact block 500 of each phase
R, 500S, and 500T have a positional relationship as shown in FIG.

[0009]

## EQU1 ## IR = sin (ωt + θR)

[0010]

## EQU2 ## IS = sin (ωt + θS)

[0011]

## EQU3 ## Assume that currents IR, IS, and IT expressed by IT = sin (ωt + θT) flow. θ
R, θS, and θT are phases of each current, and ω is an angular frequency. In this case, assuming that the current path is infinitely long and assuming that the electromagnetic force acting in the right direction in FIG. 8 is positive, the electromagnetic force between the phases acting on the movable contact table 500 of each phase from the other phase is:

[0012]

FR = −fRS−fRT = μ / 2πγ [−si
n (ωt + θR) sin (ωt + θS)-／ sin
(Ωt + θR) sin (ωt + θT)]

[0013]

FS = fST−fRS = μ / 2πγ [sin
(Ωt + θS) sin (ωt + θT) −sin (ωt +
θR) sin (ωt + θS)]

[0014]

FT = fST−fRT = μ / 2πγ [1 / 2s
in (ωt + θR) sin (ωt + θT) + sin (ω
t + θS) sin (ωt + θT)]. Here, μ is the magnetic permeability of the medium in the space, and r is the distance between the phases. If the interphase distance r is a unit length, the medium is air, and the current flowing in the R, S, and T phases is symmetric, and the phases are 0, 2π / 3, 4π / 3, and the frequency is 50 Hz, the electromagnetic force acting on each phase is As shown in FIG.

FIG. 9 shows that in the structure of the conventional circuit breaker, the R-phase movable contact block 500R is turned rightward,
0T indicates that a force is applied leftward and that the S-phase movable contact stand 500S is alternately applied left and right. This electromagnetic force also acts on the fixed contact stand 400 corresponding to each phase.

[0016]

In the conventional structure, when the distance between the phases is shortened to reduce the width of the circuit breaker in order to reduce the installation area, the fixed contact block of each phase is inversely proportional to the distance between the phases. There is a problem that the electromagnetic force acting laterally on the movable contact stand 400 and the movable contact stand 500 becomes large, and the strength of the fixed contact stand 400, the case 200 supporting the movable contact stand 500, and the like must be increased. Further, the use of the interphase electromagnetic force as the driving force for the opening operation of the movable contact stand 500 has not been considered.

An object of the present invention is to provide a circuit breaker in which not only the case 200 is easily damaged but also the width direction is narrowed.

[0018]

To achieve the above object, according to the first aspect of the present invention, a movable contact presses a fixed contact by a spring pressure, and an electromagnetic force by a current flowing through both contacts resists the spring pressure. Circuit breakers in which three-phase interrupters are arranged in parallel with each other, wherein the intermediate-phase interrupters are shifted in the direction in which the electromagnetic force of the other-phase interrupters decreases. In the bowl.

According to a second aspect of the present invention, there is provided the circuit breaker as set forth in the first aspect, wherein the interrupting portion of the intermediate phase is shifted to a position forming a triangle with the interrupting portions of the other phases.

According to a third aspect of the present invention, there is provided a handle for operating an opening / closing mechanism for opening / closing the movable contact, and the intermediate-phase interrupting portion is shifted to a position on the handle side so as not to be parallel to the other-phase interrupting portion. The circuit breaker according to claim 1, wherein the circuit breaker is arranged in a position.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a first embodiment of the present invention.
The positional relationship of the movable contact block 500 in the case of a three-phase circuit breaker is shown. From the right in the figure, the R-phase movable contact block 500
R and S phase movable contact block 500S, T phase movable contact block 500T
Are arranged in this order. Each movable contact base 500 is provided with a movable contact 501. Although not shown, handle 1
00 is located above the S-phase movable contact stand 500S. An R-phase fixed contact block 400R, an S-phase fixed contact block 400S, and a T-phase fixed contact block 400T are arranged corresponding to each phase movable contact block. A fixed contact 401 is provided on each phase fixed contact stand.

The installation positions of the R-phase movable contact stand 500R and the T-phase movable contact stand 500T are at the same distance from the surface on which the handle 100 is installed, and the S-phase movable contact stand 500S is close to the surface on which the handle 100 is installed. is there. This point is the same as described above for each phase fixed contact block. The spring 600X engaged with the movable contact 501 makes the movable contact 501 a fixed contact 401.
Is pressed. One-phase movable contact 501 and fixed contact 40
The combination with 1 is called a blocking unit.

Each movable contact stand 500R, 500S, 500
The opening operation directions of T are in the upper part of the figure and are all in the same direction. Assuming that an inter-phase distance between the R-phase movable contact stand 500R and the T-phase movable contact stand 500T is r, the R-phase movable contact stand 50R
0R and S-phase movable contact block 500S, S-phase movable contact block 500
They are arranged so that the phase distance between S and the T-phase movable contact stand 500T is equal.

The movable contact block 500 serving as such a breaking section
When the current shown in the formulas (1) to (3) flows through the movable contact block 500 of each phase in the arrangement of the fixed contact block 400 and the fixed contact block 400, and the distance between the phases of each movable contact block 500 is equal in unit length, each movable contact block 2 and 3 show the calculation results of the interphase electromagnetic force acting on the table 500.

FIG. 2 shows an inter-phase electromagnetic force component acting in a direction perpendicular to the opening operation direction of the movable contact stand 500, with the upward direction being positive. FIG. 3 shows an inter-phase electromagnetic force component acting in a direction parallel to the opening operation direction of the movable contact stand 500, with the upward direction being positive. FIG. 2 shows that even if the phase distance between the R-phase movable contact stand 500R and the T-phase movable contact stand 500T is の of that in the conventional example, the R-phase movable contact stand 500R and the T-phase movable contact stand 500T.
The magnitude of the electromagnetic force acting on the S-phase movable contact stand 500S is almost halved.

FIG. 3 shows that an upward electromagnetic force always acts on the S-phase movable contact stand 500S. Further, the electromagnetic force acts on both the R-phase movable contact stand 500R and the T-phase movable contact stand 500T in the vertical direction. Therefore, according to the present embodiment shown in FIG. 1, as shown in FIG. 3, even when the distance between the R-phase and T-phase poles is reduced, the movable contact stand 500 acts in a direction perpendicular to the opening operation direction. Without increasing the electromagnetic force,
It is possible to shorten the phase distance. In addition, as shown in FIG. 3, since the interphase electromagnetic force can be used for the opening operation of each movable contact stand 500, the opening operation can be speeded up.

That is, the spring 600X engaged with the movable contact 501 presses the movable contact 501 against the fixed contact 401, and the electromagnetic force due to the short-circuit current flowing through both contacts is an electromagnetic repulsive force against the spring pressure. In the prior art, the shut-off portions that generate the noise are arranged in parallel in three phases, but in the present invention, the shut-off portions of the intermediate phase, for example, S are shifted in the direction in which the electromagnetic force of the other phases, for example, the cut-off portions of R and T decreases. are doing. In other words, the contact position between the S-phase movable contact 501 and the fixed contact 401 is R-phase and T-contact.
It is arranged so as to be shifted upward from the contact position between the movable contact 501 of the phase and the fixed contact 401. As a result, it becomes difficult to receive the electromagnetic force of the S phase at the contact position of the R phase and the T phase, and it is difficult to vibrate in the direction (lateral) orthogonal to the opening / closing direction of the blocking part of the R phase and the T phase, and the case is damaged. The distance between the contact positions of the R-phase and T-phase movable contacts 501 and the fixed contacts 401 is smaller than the width of the contact position between the S-phase movable contacts 501 and the fixed contacts 401. It has become possible to produce narrow circuit breakers.

It can also be said that the interrupting portion of the intermediate phase S is arranged at a position forming a triangle 500X with the interrupting portions of the other phases R and T. Further, it may be said that a handle 100 for operating the opening / closing mechanism section 600 for opening and closing the movable contact is provided, and the interrupting section of the intermediate phase is arranged at a position on the handle side so as not to be in parallel with the interrupting section of the other phase.

FIG. 4 shows another embodiment of the present invention.
3 shows a circuit breaker for three phases. Storage cover 2
00 and the case 300, a fixed contact block 400, a load-side fixed contact block 410, and a movable contact block 50 (not shown).
0, a built-in opening / closing mechanism 600 for opening / closing the movable contact base 500.

Although not shown, the fixed contact block 50 of each phase
0 terminal blocks 450R, 45
A fixed contact block 400 for each phase and a movable contact block 500 are provided in a direction parallel to the planes of OSS and 450T.
00 and the movable contact stand 500 are provided at different distances from the surface provided with the handle.

The surface of the electric wire tightening terminal block 450 is parallel to the surface on which the handle 100 is mounted, and its position is set at a different distance from the surface on which the handle 100 is mounted. According to the present embodiment, it is possible to provide a narrower circuit breaker without changing the phase distance. Furthermore, since the deformation of the fixed contact stand 400 can be reduced, the shape of the fixed contact stand 400 can be simplified.

FIG. 5 shows another embodiment of the present invention.
3 shows a circuit breaker for three phases. Storage cover 2
00 and the case 300, the respective phase units 505 including the fixed contact stand 400 and the movable contact stand 500 and the like are arranged in a straight line, and are arranged so that the arranged direction is perpendicular to the surface on which the handle 100 is attached. According to the present embodiment, it is possible to provide a circuit breaker with a minimum width by arranging the respective phase units 505 on a straight line.

[0034]

As described above, according to the present invention, since the interrupting portion of the intermediate phase S is displaced from the position of the interrupting portions of the other phases R and T, the interrupting portions of the R and T phases are arranged. It becomes hard to receive the electromagnetic force of S phase, it becomes hard to vibrate in the direction perpendicular to the opening and closing direction of the cutoff part of R phase and T phase, and the case etc. becomes hard to be damaged. The width of the circuit breaker can be narrowed by the amount of shifting the S-phase cutoff portion for the inter-phase distance between the positions.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a positional relationship of a breaker of a circuit breaker according to one embodiment of the present invention.

FIG. 2 is a characteristic diagram showing an inter-phase electromagnetic force of a component perpendicular to the opening / closing operation direction acting on each blocking unit in FIG. 1;

FIG. 3 is a characteristic diagram showing an inter-phase electromagnetic force of a component parallel to an opening / closing path operation direction of a movable contact block acting on each blocking unit in FIG. 1;

FIG. 4 is a perspective view showing the appearance of a circuit breaker according to another embodiment of the present invention.

FIG. 5 is a side sectional view showing the appearance of a circuit breaker according to another embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a conventional circuit breaker.

FIG. 7 is a perspective view showing the appearance of a conventional circuit breaker.

FIG. 8 is a schematic diagram showing a positional relationship between movable contact blocks of each phase of a conventional circuit breaker.

FIG. 9 is a characteristic diagram showing the inter-phase electromagnetic force acting on the movable contact stage of each phase.

[Explanation of symbols]

Reference numeral 100: handle, 110: release device, 200: cover, 300: case, 400: fixed contact stand, 401:
Fixed contact, 450: terminal block, 500: movable contact block, 50
1 movable contact, 600 opening / closing mechanism, 700 cooling plate,
505: Phase unit.

Claims (3)

[Claims] The movable contact presses the fixed contact by spring pressure,
The electromagnetic force of the current flowing through both contacts generates an electromagnetic repulsion force that opposes the spring pressure. In this case, three phases are arranged in parallel with each other. A circuit breaker characterized by being displaced in a direction. 2. The circuit breaker according to claim 1, wherein the interrupting portion of the intermediate phase is shifted from the interrupting portion of the other phase at a position forming a triangle. 3. A handle for operating an opening / closing mechanism for opening / closing a movable contact, wherein an interrupting portion of an intermediate phase is displaced to a position on the handle side so as not to be parallel to an interrupting portion of another phase. The circuit breaker according to claim 1.