JPS6168823A - 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] [Industrial Field of Application 1] This invention relates to a circuit breaker, and in particular? I! ! This invention is directed to improving the interrupting performance of a circuit 12g7i equipped with an edge 1 force closed external wave.

[Conventional technology 1 circuit! In order to cut off a large current without any trouble with a l'i device, it is necessary to quickly and quickly catch the arc that occurs between the contacts.
It is necessary to be attracted to the arc device and receive a cooling effect. Conventionally, in order to attract this arc to the arc extinguishing device, the conductor arrangement of the contact device was considered so that Fleming's left-hand law force acting on the arc was directed toward the arc extinguishing device, or U-shaped notches were used. A large number of metal plates having a diameter of 1.5 mm were placed opposite the arc so that the electromagnetic force caused by the arc current attracted the arc into the U-shaped cut. In addition, between the arc extinguishing device and the base side of the movable contact device, a barrier having a slit 1- is constructed by a part of the closure jacket made of a molded insulator or by a separate member, and the slit is movable in the longitudinal direction. SuJ
The arm of the contact rod moves to cover the rain space with R411.
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However, in mechanical switchgear devices, especially molded circuit breakers, the electric circuit is interrupted by rotating or moving the movable contact device in parallel, but normally the movable contact device is a movable contact device that extends from the base of the movable contact device into the arc extinguishing chamber. Since the device is installed at the tip of the bowl of the rod, it is not possible to provide a complete partition between the arc extinguishing chamber and the part housing the base of the movable contact device. That is, at least an opening necessary for the penetration and opening/closing movement of the movable contact rod is necessary.

In addition, in conventional circuit breakers, the thickness of the sleeve 1- in the direction from the movable contact toward the base of the movable contact rod is usually 1 to 1.
It was extremely thin, about 2 mm. Particularly when the slit is constructed from a separate member, a plate-shaped insulator is often manufactured by press working, and the plate thickness in this case is generally thin.

[Problems to be Solved by the Invention] Since conventional circuit breakers have the above-mentioned configuration, arc gas flows into the base of the movable contact device, reducing the breaking ability and preventing input/output after breaking. There was a problem that the insulation between the terminals deteriorated.

In particular, when an arc occurs between the contacts, the internal pressure of the arc extinguishing chamber increases as the interrupting power increases, so the above-mentioned problems become more noticeable when a large amount of power is interrupted.

This invention was created to solve the above problems, and aims to provide a circuit breaker with improved breaking performance by preventing backflow of arc gas within the circuit breaker. .

[Means for solving the problem 1 - In the circuit breaker of the present invention, the arc extinguisher and other circuit parts are connected to each other in order to prevent the arc gas generated in the arc extinguisher from flowing back into other circuit parts as much as possible. Provide an insulating barrier to separate the Then, a slit is formed in this insulator barrier so that the movable contact rod can move by a predetermined distance, and this slit has a length along the length of the arm of the movable contact rod to prevent backflow of arc gas. It is formed long enough to be considerably prevented. .

[Function 1] In the present invention, the dimension along the length of the arm of the contact rod of the slit is formed to be sufficiently long, so that the fluid resistance at that portion increases to prevent the backflow of arc gas.

Embodiments In the present invention, as in conventional circuit breakers, an insulating barrier is provided between the arc extinguisher and the base of the movable contact rod. This insulating barrier is intended to isolate the arc extinguisher from other circuit parts and prevent arc gas from flowing back as much as possible, and the present invention is directed to improvements in this insulating barrier.

A slit is formed in the insulating material barrier to allow a predetermined movement of the movable contact rod. If we consider the backflow of arc gas from a hydrodynamic perspective, it is better that the fluid resistance of this slit portion be as large as possible.

According to experiments, it has been found that the following three conditions need to be satisfied in order to increase the fluid resistance of the slit portion.

■ The width of the movable contact rod and slit should be as narrow as possible, and the value obtained by subtracting the cross-sectional area of the movable contact rod from the area of the slit should be as small as possible.

■ The dimension of the slit along the length of the movable contact rod should be as large as possible.

■ Arc gas passing through the slit becomes turbulent.

In conventional circuit breakers, the above (D) is considered, but (2 and (3)) are not considered.

Therefore, in the embodiment described below, the circuit breaker is constructed taking into consideration the conditions (1) and (2) above.

1 to 7 are diagrams showing an embodiment of the present invention.

In particular, FIG. 2 is a plan view with a portion of the molded cover of the closure envelope of the three-wall circuit breaker removed, and FIG. 3 is a cross-sectional view along the line [-11 of FIG. FIG. 4 is a sectional side view of a central pole provided with a mechanism, and FIG. 4 is a sectional side view of a main part of a pole without an opening/closing mechanism. 5, 6, and 7 are a front view, a side view, and a rear view, respectively, of the molded member constituting the above-mentioned insulating barrier.

Moreover, FIG. 1 is a perspective view of the main part near the characteristic part of this embodiment. Hereinafter, one embodiment of the present invention will be described with reference to the above-mentioned FIGS. 1 to 7.

In FIGS. 2 and 3, the closure housing for accommodating a circuit breaker is formed from a molded base 1 and a molded cover 2 of molded insulation. The interior of the mold base 1 and the mold cover 2 is divided into three chambers by two different polarity insulating partition walls 1a (one of the gastric insulating partition walls 1a is not shown), and each room contains a multipolar insulating partition wall 1a. The main components are stored here.

External connection terminals 3, 3- are provided at both ends of the mold base 1.
is provided. One end of the fixed terminal conductor 4 constituting the fixed contact device 61 is connected to the external connection terminal 3, and the other end is folded back to form a fixed contact rod 5. A fixed contact 6 is provided on the upper surface of the fixed contact rod 5.
is provided. As a movable contact device, a movable contact rod 7 is provided substantially parallel to the fixed contact rod 5, and a movable contact 8 is provided at the tip thereof so as to face the fixed contact 6. Further, the movable contact rod 7 is rotatably supported by a contact holder 10 via a shaft 9. An insulating opening/closing movement arm 11 that connects the multipolar contact holders 10 so as to operate together is rotatably supported by a fixed frame 12, and is operated to an open position or a closed position by an opening/closing operation mechanism. As an opening/closing operation mechanism, the toggle link 13 has one end connected to the contacts 1 to holder 10 by a shaft 9, and the other end connected to one end of another toggle link 15 by a toggle link shaft 14. In addition, the other end of the toggle link 15 is connected to the trip lever 1.
6. The opening/closing lever 17 has a bifurcated notch (not shown) at its lower end, is rotatably engaged with a protrusion (not shown) provided on the fixed frame 12, and has an operating handle 18 attached to its upper end. be done. The operating spring 19 is installed between the installation pin 20 provided on the opening/closing lever 17 and the toggle link shaft 14 to form an opening/closing toggle link shaft structure.

One end of the trip lever 16 is releasably engaged with a book bin 21a provided on the hook 21.

The trip member 22 for multipolar interlocking is rotatably supported by the fixed frame member by a rotary support plate 22a integrally equipped with an engaging claw 22b. The engaging claw 22b is the engaging projection piece 21 of the hook 21 which is also rotatably supported on the fixed frame member.
b. One end of the contact spring 23 is possible! P7I so as to contact the contact rod 7,
The other end is installed so as to come into contact with the contact holder 10, and the movable contact rod 7 is always biased in the closing direction.

The flexible conductor 24 has one end connected to the movable contact piece 7 and the other end connected to the relay connection terminal 26 via the connection member 25 . The relay connection terminal 26 is connected to one end of a heater 27 and a bimetal 28 that are integrally formed. The other end of the heater 27, which is bent and extends upward, is connected to the external connection terminal 3- via the flexible conductor 29 and the conductive terminal 30. An adjustment screw 31 is provided at the upper end of the bimetal 28 so as to face the trim member 22. TfXt! 1'f
A U-shaped fixed core member 32 of the tripping electromagnet is formed to surround the bimetal 28 and the heater 27, and a movable iron piece 33 is rotatably provided opposite the legs of the fixed core member 32. . A movable iron piece return spring 50 is installed between the movable iron piece 33 and the fixed iron core member 32.

The arc extinguishing chamber 34 is partitioned to accommodate an arc extinguishing device 35. The arc extinguishing device 35 is constructed by distributing arc extinguishing grids 36 in which notches 36 are formed at intervals. Further, the arc extinguishing chamber 34 is provided with an exhaust port 37 in the end wall of the closed envelope.

The insulator barrier 38 is provided to partition the arc extinguishing chamber 34 from the room 51 that accommodates the movable contact mounting neck section, and the arm section of the movable contact suspension rod 7 passes through the slit formed in the insulator barrier A738. What is the configuration that allows rotational movement?

J3, the arm portion of the movable contact suspension rod 7 is formed into a plate shape, and the movable contact 8 is provided on the lower short side surface of this arm portion. That is, the arm portion of the movable contact suspension rod 7 is arranged to be perpendicular to the contact surface of the movable contactor 8.

Then, the movable e-contact suspension rod 7 is rotated in the vertical direction in FIG. 1, so that the long side surface of the arm portion of the movable contact suspension rod 7 is rotated so as to face the wall surface of the slit.

Next, the structure of the insulator barrier 38 will be described in detail with reference to FIGS. 1 and 5 to 7.

The insulator barrier 38 includes a pair of left and right insulator molded members 39.
It is formed by combining 39-.

The three molded members include a base 39a, a recess 41 for holding the fixed contact suspension 5, a slit surface 42 forming a slit in which the movable contact suspension 7 performs interlocking, and an arc extinguishing device 35. Notch in arc extinguishing grid 36? A partition wall 43 that butts and engages with the legs forming the F7I36-, and a partition wall 44 that engages with the partition walls of various storage grooves are formed. The base portion 39a is abutted against the base portion of the molded member 39' and is coupled with a screw. For this purpose, a screw through hole 40 is formed in the base portion 39a. Furthermore, a recess 42a is formed in the side surface 42 of the slit portion. This recess 42
The role of a is to generate turbulence in the arc passing through the slit, thereby increasing the fluid resistance of the slit portion. Note that the slit portion is formed so that the length along the length direction of the arm portion of the movable contact suspension rod 7 is sufficiently longer than that of a conventional insulating material barrier. The length of the slit portion is formed to be longer than the thickness of the movable contact suspension rod 7, for example.

It should be noted that the molded member 39' is also constructed in substantially the same manner as the three molded members described above, so a description thereof will be omitted.

The fixed contact suspension rod 5 and the movable contact suspension rod 7 are sandwiched from both sides by molded members 39 and 39' as described above, and the fixed contact suspension rod 5 is
The insulator barrier 38 is installed and fixed by inserting the base 39a between the terminal conductor 4 and the fixed terminal conductor 4 and coupling them together with screws. In this embodiment, the central pole with the opening/closing operation mechanism is provided with an arc extinguishing chamber 34 and a chamber 5 accommodating the base of the movable contact device by means of an insulating barrier 38 as shown in FIG.
1 is not completely partitioned due to the storage space in the closing groove, but in the case where there is no mechanism for opening and closing, there is a lower part 9 of the protruding partition wall 2a provided on the mold cover 2, as shown in FIG. =: and insulator Paris! By abutting the upper ends of 38, the arc extinguishing chamber 34 and the chamber 51 that accommodates the base of the movable contact device are almost completely partitioned off.

In the circuit breaker of the embodiment described above, the insulator barrier 3
The slit 8 is slightly wider than the plate thickness of the movable contact suspension rod 7, and is formed sufficiently large in the length direction of the arm of the contact suspension rod 7, so that the arc gas in the slit portion is Fluid resistance becomes sufficiently large. Therefore, it is possible to effectively prevent the arc gas generated at the time of interruption from flowing back into other circuit parts through the slit portion of the insulating barrier 38. Therefore, improving the breaking performance of the circuit breaker,
Moreover, deterioration of the insulation between the input and output terminals 3-3- of the circuit breaker can be prevented.

Further, by providing the recess 42a on the opposing surface of the slit, the arc gas passing through the opposing surface becomes a turbulent flow, increasing fluid resistance, and furthermore, it is possible to enhance the effect of preventing arc scum from flowing back.

In addition, as mentioned above, in the central pole equipped with the opening/closing operation mechanism, although the partition between the arc extinguishing chamber 34 and the chamber 51 that houses the base of the movable contact device is not perfect, the opening/closing operation mechanism has a relatively large fluid resistance. Therefore, it has the function of blocking arc gas and can achieve the desired purpose. However, it is preferable that the arc extinguishing chamber and other circuit parts be completely partitioned off, similar to poles not equipped with an opening/closing operation mechanism.

Further, in the above-described embodiment, a circuit breaker is shown in which the contacts are opened and closed by the rotational movement of the movable contact suspension rod 7, but the present invention is not limited to this, and for example, the movable contact It can also be applied to a circuit breaker in which contacts are opened and closed by reciprocating the hanging rod in the longitudinal direction or in a direction perpendicular to the longitudinal direction.

[Effects of the Invention] As described above, according to the present invention, since the length of the slit in the insulator barrier (the length along the length direction of the arm of the movable contact suspension rod) is formed sufficiently long, the slit The fluid resistance can be increased at the end of the arc, thereby significantly preventing backflow of arc gas. Therefore, the internal pressure in the arc extinguishing chamber can be increased and arc gas can be quickly discharged, and the breaking performance of the circuit breaker can be significantly improved.

4. Brief Description of the Drawings FIG. 1 is a perspective view of essential parts showing the characteristic parts of an embodiment of the present invention. FIG. 2 is a plan view with a portion of the molded cover of the closure envelope of a three-wall circuit breaker according to an embodiment of the present invention removed. FIG. 3 is a sectional view taken along line 1--2 in FIG. 2. FIG. 4 is a sectional side view of the main part of a pole without an opening/closing operation mechanism. FIG. 5, FIG. 6, and FIG. 7 are a front view, a side view, and a rear view, respectively, of a molded member that forms an insulator balano.

In the figure, 1 is a mold base, 2 is a mold cover, 5 is a fixed contact hanger, 6 is a fixed contact, 7 is a movable contact hanger, 8 is a movable contact, 34 is an arc extinguishing chamber, and 35 is an arc extinguisher. ,
38 indicates an insulator barrier.

Claims (4)

[Claims] (1) A circuit breaker that is housed in an insulating closed jacket and opens electrical contacts to interrupt the current when an excessive current flows, the fixed contact constituting one of the electrical contacts; a movable contact constituting the other of the contacts; a movable contact rod in which the movable contact is mounted at a position facing the fixed contact and whose movement opens and closes the electric contact; and the electric contact. an arc extinguishing device provided near the arc gas for cooling arc gas generated when the current is cut off, and a slit that inserts the arm portion of the movable contact rod and allows the movable contact rod to move therein. What is claimed is: 1. A circuit breaker comprising: an insulator barrier formed thereon, wherein the slit has a sufficiently large dimension along the length direction of the arm of the movable contact rod. (2) The slit is formed such that the dimension along the length direction of the arm of the contact rod is at least larger than the plate thickness of the arm of the movable contact rod. circuit breaker. (3) A partition wall extending in the direction of the insulator barrier is formed on the inner wall surface of the insulator closure jacket, and the insulator barrier and the partition wall cooperate to prevent backflow of the arc gas. Claim 1 or 2 characterized by
Circuit breakers as described in section. (4) The circuit breaker according to any one of claims 1 to 3, characterized in that a recess is formed in an inner wall surface of the insulator barrier that constitutes the slit. .