JPS6049527A - 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] [Technical field of invention] This invention relates to a circuit breaker.

[Prior Art] Figures 1 to 3 are cross-sectional views showing conventional circuit breakers.
Each shows a different operating state.

(1) is a cover 1 (2) is a base, and the cover (1) and the paste (2) constitute a container (3). (4) is a fixed contact, and one end of its fixed conductor (5) has a fixed contact (8
), and the other end is a terminal portion to be connected to an external conductor (not shown). A movable contact (7) has a movable contact (8) at one end of a movable conductor (8) opposite to a fixed contact (6). (1o) is a J moving contact device,
(11) is a movable arm, which is fixed to the cross spar (12) and is configured to be opened and closed when each pole is spaced. (13
) is an arc extinguishing chamber in which an arc extinguishing plate (14) is held by a side plate (15). (16) is a toggle link mechanism, which is composed of a lower link (17) and a lower link (18).

One end of the upper ring (17) is connected to the fredle (18), and the other end is connected to one end of the lower link (18), respectively.
(21). Drinks (18
) is the other end of the movable arm (1) of the movable contact device (lO).
1). (22) is the raising/lowering operation/handle, (23) is the operating spring, and the toggle link mechanism (16)
(2+) and the operating handle (22). (24) and (25) are thermal and electromagnetic trip mechanisms, respectively, and when activated, the trip bar (28) is rotated counterclockwise by a bimetal (26) and a movable iron core (27), respectively. ing. (29) is a latch whose one end is engaged with the trip bar (28) and the other end is engaged with the fredle (18).

If the operating handle (22) is tilted to the closing position with the fredle (18) locked to the latch (28), the toggle link mechanism (16) will extend and the shaft (21) will be locked to the fredle (19) and movable. The contact (9) is joined to the fixed contact (6).

This state is shown in FIG.

Next, when the operation handle (22) is tilted to the closing position, the toggle link mechanism (16) is bent to separate the movable contact (8) from the fixed contact (6), and the movable child arm (11) moves toward the fredl shaft (30). ). This state is shown in FIG. Furthermore, if an overcurrent flows through the circuit in the closed state shown in FIG.
8) is disengaged, the frettle (19) rotates clockwise around the frettle shaft (30), and the stopper shaft (31) rotates clockwise around the frettle shaft (30).
). Fredl (18) and Shichilink (17)
Since the connecting point exceeds the line of action of the operating spring (23), the toggle link mechanism (16) is bent by the spring force of the operating spring (23), and each pole is interlocked by the crossbar (12) to perform automatic shutoff. . This state is shown in FIG.

Next, we will explain the behavior of the arc that occurs when the circuit breaker interrupts the current.

Now, when the Uf moving contact (8) and the fixed contact (6) are in contact, the power is transferred from the power supply side to the fixed conductor (
5), is supplied to the load side via the fixed contact (8), the movable contact (8), and the i'f dynamic conductor (8) in sequence. If a large current such as a short circuit current flows through this circuit in this state,
As mentioned above, the rM moving contact (8) is the fixed contact (6).
separated from At this time, J- marked fixed and movable contacts (
An arc (32) is generated between the fixed and movable contacts (8) and (9), and an arc voltage is generated between the fixed and movable contacts (8) and (9). This arc voltage increases as the separation distance of the movable contact (9) from the fixed contact (6) increases, and at the same time, the arc (32) is attracted toward the arc extinguishing plate (14) by magnetic force. Due to elongation, it rises further.

In this way, the arc current reaches a current zero point and the arc (32) is extinguished, completing the interruption. During such instant operation, a large amount of energy is generated between the movable contact (8) and the fixed contact (8) by the arc (32) within a short period of time, ie, within a few milliseconds. Therefore, the temperature of the gas in the container (3) rises and the pressure also rises rapidly, but this high-temperature, high-pressure gas
The outlet (33) formed in the side wall on the power supply side of
released into the atmosphere.

In the operation of the circuit breaker as described above, the arc resistance R is generally given by the following formula. That is, R-ρ □ However, R: Arc resistance (Ω) ρ: Arc resistivity (Ω・cm) Sentence: Arc length cm) S: Arc cross-sectional area (C♂) However, in general, large currents of several KA or more In a short arc (32) with a large arc length of 50 mm or less, the arc space is occupied by metal particles. Moreover, this release of metal particles occurs in a direction perpendicular to the contact surface. In addition, the released metal particles have a temperature close to the boiling point of the metal at the contact point at the time of release, and as soon as they are injected into the arc space, they are heated to high temperature and high pressure by being injected with electrical energy. Ru.

If the contacts (e) and (9) are exposed to such conditions for a long time, the contacts (8) and (9) may melt. For this reason, as shown in FIGS. 4(A) and 4(B), an arc runner (34) is disposed on the rear side of the contact fixing position on the fixed conductor (5). This is done by quickly moving the leg of the arc (32) generated between the contacts (8) and (9) on the fixed contact (6) side to the arc runner (34). ) whose main purpose is to protect the

However, in the case of item 2, even if the arc (32) is dislocated to the arc runner (34), it is difficult to completely separate from the fixed contact (6), and the arc current at the time of this dislocation is as shown in Fig. 4 (B). As shown by the arrow, the current flows from the base end of the fixed conductor (5) bypassing the fixed contact (6) side to the arc runner (34), so that the fixed contact (6) is overheated due to the passage of the current, and therefore the fixed contact (6) is overheated. There was a drawback that the contact point (8) was easily worn out.

[Summary of the Invention] This invention was made in order to eliminate the drawbacks of the conventional ones as described above. It is an object of the present invention to provide a circuit breaker which can suppress wear of contacts and improve breaking performance by forming a shape with a fixed piece and further forming a bent protrusion on the conductor. .

[Embodiment of the Invention] Fig. 5 and Figs. 6 (A) to (C) show the configuration of main parts in an example of a circuit breaker according to the present invention, and are the same as Figs. 1 to 4. The parts are marked with regression and their explanations are omitted.

In the figure, (51) is a fixed contact, and the fixed conductor (51) is a fixed contact.
2) and a fixed contact (6). This fixed conductor (5
The distal end side (520) of the fixed conductor (52) is bent into a substantially U-shape with an opening on the conductor main surface side, and the distal end of the vertical piece (520a) on the load side of the fixed conductor (52) is connected to the contact fixing piece (520). 521
) is extended toward the power supply side. (53) is the power supply side vertical piece (520) of the approximately U-shaped tip (520).
b) is a protrusion bent on the fixed conductor (52) located at the upper end, and is for transferring the leg of the arc (32) from the fixed contact (6) to the power source side.

(54) is a pressure reflector made of a high-resistance material having a higher resistivity than the fixed conductor (52), and the fixed conductor (54) surrounds the surrounding conductor portion of the fixed contact (6).
52). High-resistance materials include, for example, organic or inorganic insulators or leakage-resistant metals such as nickel, iron, copper-nickel, copper-manganese, iron-nickel, iron-chromium, etc. provided in a manner. As shown in FIG. 6, a pressure reflector (55) having the same structure as above is also provided on the IJ hinge conductor (8) side.

Next, the operation of the above configuration will be explained.

The opening/closing operations by the fixed and movable contacts (51) and (?) are the same as those of the prior art, and will not be described further.

With the opening operation of the moving contact (7), an arc (32) is generated between the contacts (I() and (9)) as shown in FIG. 6(A). When the arc (32) is attracted by the magnetic force of the arc extinguishing plate (14) and begins to expand, the top of the bent protrusion (53) formed on the fixed conductor (52) is heated and the arc (32) 6 (B
'), it moves from the fixed contact (6) to the protrusion (53) side, and then - (
The arc moves to the slope (53a) on the power supply side of the first protrusion (53), is further extended, and then extinguished.

In other words, the legs of the arc (32) are
) side, the arc (32) receives a driving force from the current in the direction shown by the arrow i in FIG. It is extended in a curved shape between the slope (538) of 53) and the b1 moving contact (9) side. Therefore, the arc length (the sentence mentioned above) becomes long, and becomes [2 or discontinuously distorted]. Moreover, the shape of the conductor is such that the arc current does not pass through the fixed contact (6) when the arc (32) moves to the bending protrusion (53), and the legs of the arc (32) are connected to the bending protrusion (53).
3) by moving to the slope (53a) of arc (
32) is quickly and completely separated from the fixed contact (6) side, so that the wear and tear of the fixed contact (6) etc. can be suppressed as much as possible.

By the way, at the beginning of the opening, 'I' shown by the arrow i above
As the current flows in the direction of the vertical piece (520), the leg of the second arc (32) is pushed toward the fixed contact (6) until just before it moves to the bending protrusion (53). Initial current limiting is obtained due to the action of trying to hold the current, but especially due to the arc-squeezing action of the pressure reflectors (54) and (55) covered by the surrounding conductor at the second contact point (fi) and (9). In addition, the above-mentioned current limiting property can be ensured.

Of course, this effect can also be achieved even when only one of the pressure reflectors (54) and (55) is provided.

FIG. 8 shows another embodiment of the present invention, in which the surface of the bending protrusion (53) is covered with a magnetic metal layer (81), whereby the legs of the arc (32) are This has the advantage that the conductor (52) can be more easily moved toward the bending protrusion (53), the conductor (52) can be protected, and the generation of molten material can be suppressed. This magnetic metal layer (81
) may be a fixed plate, and the means for forming it may be appropriately selected.

By the way, the bending protrusion (53) in each of the above embodiments may be formed at the position shown in FIG. 9 if the leg of the arc (32) can move from the fixed contact (8) to the power supply side. It can be selected as appropriate, and its shape may be rectangular as long as the fixed conductor (51) is bent.

[Effects of the Invention] As described above, the present invention specifies the shape of the tip end side of the conductor of one of a pair of electric contacts, and further provides a bending protrusion on this conductor that moves the arc leg toward the power source side. By forming this, it is possible to provide a circuit breaker that can improve the breaking performance without suppressing the wear of the contacts.

[Brief explanation of drawings]

Figures 1 to 3 are cross-sectional views of a conventional circuit breaker in different operating states, and Figures 4 (A) and (B) are perspective views of a fixed contact with an arc runner in the conventional circuit breaker, respectively. FIG. 5 is a perspective view showing a fixed contact piece incorporated in an example of the circuit breaker according to the present invention, FIG. 6 (A) to (C), and FIG. FIG. 9 is a sectional view of a fixed contact showing a modified structure of the main part of the present invention. . (3)...container, ridge), (51)...electric contact,
(8), (52)...conductor, (14)...arc-extinguishing plate, (32)...arc: (53)-fist/bending protrusion, (520)...approximately U-shaped Tip, (520a)...
- Vertical piece part, (521)...Contact fixing piece part. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Daikan Addendum Figure 1 2 Procedural amendment (voluntary) Commissioner of the Japan Patent Office 1 Indication of case Japanese Patent Application No. 156708/1982 2 Title of invention Circuit breaker: 3. Representative Hitoshi Katayama of the person making the amendment, Department 5 of Mitsubishi Electric Corporation, ``Claims'' column of the specification to be amended. 6. Contents of amendment A. Description: (1) The scope of claims will be amended as shown in the attached sheet. Claims after separate paper amendment [(1) At least one pair of electrical contacts that are configured of a conductor and a contact fixed thereto and that open and close in a container, and the opening operation of the electrical contact and a plurality of arc-extinguishing plates disposed within the container to extinguish arcs that sometimes occur between the contacts, and a conductor of one of the pair of electrical contacts. A substantially U-shaped cedar whose tip end side is open to the main surface side of the conductor is provided with the tip of the vertical piece on the load side of the tip portion extending toward the power source side as a contact fixing piece part, and the arc at the time of the above-mentioned opening operation is caused by this conductor. A circuit breaker having a bent protrusion for moving the leg from the contact fixing piece to the power supply side. [2] The circuit breaker according to claim 1, wherein the surface of the bent opening is formed of a magnetic metal layer. ” Tokukai Sho GO
-49527(7) 139-

Claims (2)

[Claims] (1) At least one pair of electrical contacts consisting of a conductor and a contact fixed thereto, which open and close within the container, and for extinguishing the arc that occurs between the contacts when the electrical contact opens and closes. a plurality of arc-extinguishing plates arranged in the container, and the tip side of the conductor of one of the pair of 'IIE gas contacts is placed on the main surface side of the conductor. The conductor is formed into an open approximately U-shape, and the tip of the load-side straight piece of the approximately U-shaped tip extends toward the power supply side as a contact fixing piece, so that the arc foot during the above-mentioned opening operation is A circuit breaker formed with a bent protrusion that is moved from the contact fixing piece to the power source side. (2) The circuit breaker according to claim 1, wherein the surface of the bent protrusion is covered with a magnetic metal layer.