KR101051517B1 - Circuit breaker - Google Patents

Abstract

(assignment)
The arc gas exhaust structure of the circuit breaker improved by reducing the number of parts and the number of assembly processes compared with the conventional structure to reduce the cost, and at the same time ensure high safety.
(Solution)
A circuit breaker in which a main circuit case made of a molded resin comprising a case 2 and a cover 3 is provided with a current interrupting unit, an opening / closing mechanism unit, and an overcurrent trip device, at a power supply side end of the cover 3, The shielding wall part 3b which opened the gas exhaust port 3c through 10) was integrally molded, and the shielding wall part 3b was covered with the gas exhaust port 3c from the outside, and the flexible protective sheet 15 was overlapped. The end of the protective sheet 15 is latched and supported by the cover 3.

Description

Circuit breaker {CIRCUIT BREAKER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker for a circuit breaker, an earth leakage breaker, and the like, and more particularly, to a gas exhaust structure of a main body case which releases arc gas generated in an arc extinguishing chamber to the outside of the case with overcurrent blocking. .

As is well known, the circuit breaker described above includes a main circuit contact mechanism, a arc extinguishing device, a current interrupting part comprising a movable contact and a fixed contact, and an arc extinguishing device in a main body case of a divided structure combining a case and a cover made of a mold resin. And an opening / closing mechanism part and an overcurrent trip device. When the overcurrent trip device operates by detecting an overload current flowing through the main circuit, the switch mechanism trips to open the main circuit contact, and drives an arc generated between the fixed contact and the movable contact to the extinguishing device to limit the current. Shut off.

Next, the structure of the above-mentioned circuit breaker (center pole part of a 3-pole circuit breaker) is shown in FIG. In the figure, 1 is a case 2, a cover 3, and a main body case made of molded resin consisting of a top cover 4 attached to the cover 3, 5 is a power supply side terminal, 6 is a load side terminal, and 7 is a bar. A fixed contactor formed integrally with the power supply terminal 5 made of a conductor, 8 is a movable movable contactor, 9 is a movable contactor holder, and 10 is a grid type extinguishing device arranged along the opening movement path of the movable contactor 8, 11 is an opening / closing mechanism part which consists of a toggle link mechanism connected with the movable contact 8, 12 is an operation handle, and 13 is an overcurrent trip device. In addition, the case 2 and the inside of the cover 3 are partitioned between the pole partition walls and the chamber which accommodates the current interruption part of each pole, and an arc extinguishing apparatus separately.

Moreover, the gas exhaust port 3a corresponding to each pole is opened in the end surface of the power supply terminal side of the cover 3 opposite to the said arc extinguishing apparatus 10, and it generate | occur | produced in the arc extinguishing chamber at the time of overcurrent interruption. The arc gas is released from the arc chamber of the arc extinguishing device 10 to the outside of the case through the gas exhaust port 3a.

In addition, although the circuit breaker shown in figure is drawn in the position which puts the operation handle 12 horizontally upward, when installing the said circuit breaker in half, such as a control panel, the power supply side terminal 5 mentioned above is moved upwards. The circuit breaker is mounted on the supporting rail on the half side and used in the upright position.

By the way, in the state which installed the circuit breaker of the said structure in the half, the said gas exhaust port 3a opens upwards, and the foreign matter and dust which fell from above upwards are the arc-extinguishing chamber inside case inside the gas exhaust port 3a. There is a risk of breaking. Therefore, in the conventional circuit breaker, as shown in FIGS. 6 (a) and 6 (b), the gas vent hole is formed in the plate surface by facing the exhaust port 3a opened in the power supply side end face of the cover 3. It has the flexibility which overlapped the back board 14 so that the back board 14 made of the insulating material which disperse | distributed and drilled 14a and opposed to the extinguishing device 10, and the said gas bleed hole 14a from the outside is covered. The thing of the structure which inserted the lower end part of the protective sheet 15 into the slit-shaped groove | channel formed in the inside of the case 2, and latched and supported it is known (for example, refer patent document 1).

In the above-described configuration, the protective seat 15 functions as a kind of diaphragm type check valve, and normally, the protective seat 15 covers the gas bleed hole 14a which the protective seat 15 drills in the back plate 14, so that the dust in the main body case 1 is prevented. , To prevent foreign objects from invading. On the other hand, when the overcurrent is cut off, the protective sheet 15 is bent to the outside under the wind pressure generated in the arc-extinguishing chamber to open the gas releasing hole 14a of the back plate 14, and the arc gas is discharged to the outside of the case. In addition, this protective sheet 15 is an insulating sheet having a flame retardance, heat resistance and flexibility of 0.5 mm or less in thickness (for example, NOMEX paper: DuPont Daijin Advanced Paper Co., Ltd.) Product name).

[Patent Document]

Patent Document 1: Japanese Patent Application Laid-Open No. 8-321244

By the way, in the conventional circuit breaker provided with the said arc gas exhaust structure in the main body case, since the opening part of the cover 3 which communicates with the extinguishing device 10 is covered with the back board 14 of a separate component, the number of parts As a result, the assembly labor is increased, resulting in high cost. In addition, since the back board 14 and the protective sheet 15 are assembled and held on the case 2 side of the main body case 1, the back board 14 and the protection sheet 15 are held at the assembly step of attaching the cover 3 to the case 2. The operation | work which confirms and adjusts the fitting position of 14 and the cover 3 is required.

In addition, when the pressure of the arc gas generated in the arc chamber is increased with the interruption of a large current such as a short circuit current, the back plate 14 inserted into and supported in the engaging groove of the case 2 falls out of the groove and together with the arc gas. There is a risk of trouble being called out of the case and flying away.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to solve the above problems, and to reduce the number of parts and assembly labor compared to the conventional structure, to reduce the cost, and to improve the safety of the circuit breaker. It is to provide the arc gas exhaust structure of the.

In order to achieve the above object, according to the present invention, in a circuit breaker equipped with a main circuit contact, an arc extinguishing device, an opening / closing mechanism part, and an overcurrent trip device in a main body case made of a molded resin consisting of a case and a cover,

On the power supply side end of the cover of the main body case, a shielding wall portion which opens the gas exhaust port communicating with the extinguishing device is integrally formed, and the shielding wall portion is covered with the gas exhaust port from the outside, and then the flexible protective sheet is laminated. The end portion of the protective sheet is held by the cover of the main body case (claim 1), and is specifically configured in the same manner as in the following description.

(1) The shielding wall portion of the cover extends so that its tip side enters the case inside the main body case and is assembled (claim 2).

(2) On both left and right sides of the protective sheet, a female support piece protruding laterally from the lower end thereof is formed, and the support piece is inserted into the engaging groove provided in the gap partition of the cover of the main body case and held. (Claim 3).

(3) The upper edge of the said protective sheet is fixed to the upper edge of the shielding wall part formed in the cover of the main body case, and it is set as the engaging protrusion (claim 4).

According to the said structure, the shielding wall part which opened the gas exhaust opening was integrally shape | molded with the cover of a main body case, and compared with the conventional structure which assembled the back board of the separate component which perforated the gas drainage hole in the board surface in the main body case, the parts of a main body case The number of products and the number of assembly processes are reduced, and the cost of a product can be reduced. In addition, the shielding wall portion integrally formed with the cover can be secured without high risk of accidentally falling off due to the wind pressure of the arc gas.

In addition, the protective sheet, which prevents dust and foreign matter from entering the main body case from the exhaust port of the shielding wall, overlaps with the shielding wall and is held by the cover, thereby protecting the protective sheet in the assembly step before attaching the cover of the main body case to the case. It can be assembled at a predetermined position. This improves the assembly workability as compared with the conventional structure in which the protective sheet is held on the case side.

1 (a) is a sectional view of a power supply side end of a circuit breaker having an arc gas exhaust structure according to the present invention; (b) is an enlarged view of portion B of FIG. 1 (a)
Fig. 2 is a front view of the arc gas exhaust structure as seen in the direction of arrow P in Fig. 1, (a) is a state in which a protective sheet is mounted, and (b) is a state in which a protective sheet is removed.
FIG. 3 is an explanatory diagram of a procedure of assembling work of the protective sheet shown in FIG. 2. FIG.
4 is an exploded perspective view of the entire circuit breaker showing a state before the cover of the body case corresponding to the configuration of FIG. 1 is coupled to the case;
Fig. 5 is a cross-sectional view of a circuit breaker for wiring that is an object of the present invention.
Fig. 6 is a view showing an arc gas exhaust structure provided in a conventional circuit breaker, (a) is a sectional view of the side of the power supply side end portion of the circuit breaker, (b) is a back plate and a protective sheet provided in (a). A perspective view showing the structure.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on the Example shown to FIGS. 1 is a cross-sectional view of a circuit breaker showing an arc gas exhaust structure provided at the power supply side end of the main body case, and FIG. 2 is a front view of the shielding wall portion seen from the arrow P direction of FIG. 1, and (a) is a protective sheet. (B) is a figure which shows the state which carried out the protection sheet, FIG. 3 is explanatory drawing of the mounting procedure of a protection sheet, FIG. 4 is the whole circuit breaker which shows the state before joining the cover of a main body case to a case. Is an exploded perspective view, in which members corresponding to FIGS. 5 and 6 are denoted by the same reference numerals and description thereof will be omitted.

That is, in the illustrated embodiment, the shielding wall portion 3b is molded integrally with the cover 3 at the power supply side end of the cover 3 in the gas discharge side of the extinguishing device 10 mounted in the main body case. Moreover, the gas exhaust port 3c which communicates with the arc extinguishing device 10 is opened in the wall surface of the said shielding wall part 3b. In addition, the protective wall 15 is overlapped with the shielding wall portion 3b so as to cover the gas exhaust port 3c from the outside, and then the protective sheet 15 is held by the cover 3. In addition, this protective sheet is an insulating sheet having a thickness of 0.5 mm or less having a flame retardance, heat resistance, and flexibility as described above (for example, NOMEX Paper: DuPont Daijin Advanced Paper Co., Ltd.) It is made of).

Here, the shielding wall part 3b extends so that the front end part (lower end side of illustration) may enter into the inside of the case 2 of the main body case, and extend the side edge of the shielding wall part to the inner wall side of the case 2. It fits in the fitting groove 2b provided, and is made to support it at an assembly position.

On the other hand, the protective sheet 15 is formed with a female support piece 15a (see Figs. 2A and 3) that protrudes along the left and right sides from the lower end portion thereof. The tip is inserted into the engaging groove 3e (see Fig. 2 (b)) provided in the pole partition 3d of the cover 3 from below and supported at a predetermined position. In the illustrated embodiment, the engaging projection 3f (see Figs. 1 and 2) is formed at the upper edge of the shielding wall portion 3b, and the protective sheet (3) is provided on the back side of the engaging projection 3f. Insert the top of 15) to hang. In addition, this protective sheet 15 is supported on the cover 3 by the above procedure by overlapping with the shielding wall part 3b in the step before assembling the cover 3 to the case 2 in the assembly process of a circuit breaker. I can let you do it.

According to the above configuration, in the usual use state in which the circuit breaker is placed in a half with the power supply side end portion of the main body case upward, the gas that the protective sheet 15 superimposed on the shielding wall portion 3b of the cover 3 opens in the shielding wall portion. The exhaust port 3c is closed from the outside to prevent dust and foreign matter from entering the case.

On the other hand, when the overcurrent flowing through the circuit is detected and the circuit breaker trips the current, the protective sheet 15 is deformed to be deflected outward by receiving the gas pressure of the arc gas generated in the extinguishing chamber of the extinguishing device 10. The arc gas is released to the outside through the gap formed between the wall portion 3b and the gas exhaust port 3c. In this case, since the shielding wall part 3b is molded integrally with the cover 3, even if high arc gas pressure is applied with large current interruption, such as a short circuit current, the back board 14 of a conventional structure (refer FIG. 6). There is no risk of falling out of the case by accidentally falling off, so high safety can be ensured. In addition, when generation | occurrence | production and discharge | release of arc gas stop after a current interruption, the protection sheet 15 returns to an original state, and it overlaps with the shielding wall part 3b again, and closes the gas exhaust port 3c.

1: body case
2: case
2b: fitting groove
3: cover
3a: shielding wall part
3c: gas exhaust
3e: Engagement Home
3f: engaging projection
5: Power side terminal
7: fixed contactor
8: operation contactor
10: arc extinguishing device
11: opening and closing mechanism
13: overcurrent trip device
15: protective sheet
15a: support piece

Claims (4)

In a circuit breaker equipped with a main circuit contact, an arc extinguishing device, an opening / closing mechanism part, and an overcurrent trip device in a main body case made of a molded resin consisting of a case and a cover,
The shielding wall part which opened the gas exhaust port which communicated with the said arc-extinguishing apparatus was integrally formed in the power supply side edge part of the cover of a main body case, and the said shielding wall part covered the said gas exhaust port from the outside, overlapping a flexible protective sheet, and then A circuit breaker characterized in that the end portion is held by a cover of a main body case. The method of claim 1,
The shielding wall part extended so that the front end side may enter into the case inside of a main body case, and is assembled. The method of claim 1,
A circuit breaker characterized by forming a female support piece that protrudes laterally from its lower end on both left and right sides of the protective sheet, and inserting the support piece into the engagement groove provided in the gap partition of the cover of the body case. . The method of claim 1,
A circuit breaker characterized in that an engagement protrusion is formed on the upper edge of the shielding wall portion to secure the upper end of the protective sheet.

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