JPH0643992U - Circuit breaker - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a circuit breaker that simplifies the arc extinguishing structure, reduces the number of parts and the number of assembly steps, and can be manufactured at low cost. [Arrangement] An arc suction plate having a commutation portion 22c of the arc, which is formed by a magnetic material in a U-shape by a facing piece 22a and a connecting piece 22b so as to attract the arc A generated between both contacts 4 and 6. 22 is provided in the accommodating space 1a of the case 1, and the exhaust plate 21 mounted on the gas discharge passage 1b of the case 1 is made of a metal material and is a commutation part of the first commutation part 21b and the arc suction plate 22 that are close to the contact point A second commutation part 21c was formed adjacent to 22c.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a circuit breaker having a simplified arc extinguishing structure.

[0002]

[Prior art]

 As a general circuit breaker having an arc extinguishing structure, there is one having a structure shown in FIG. In the figure, 1 is a case made of an insulating material such as plastic that forms a housing together with a cover, and has a box-like shape with an opening on one side, and accommodates the members described below. This figure shows the case 1 without the cover that covers the opening. 3 is a fixed contactor having a fixed contact 4, 5 is a movable contactor having a movable contact 6, 7 is a handle, and 8 is a handle 7 that operates the handle 7 to open and close the fixed contacts 4 and 6. An opening / closing mechanism section 8 including a is an abnormal current detecting means that acts on the opening / closing mechanism section 8 to perform a trip operation when an abnormal current flows.

Further, the case 1 has a housing space 1a for housing the contacts 4, 6 and gas discharge paths 1b, 1b for communicating the housing space 1a with the outside. Further, as shown in FIG. 6, exhaust plates 21, 21 made of heat-resistant resin or metal plate material having a plurality of gas exhaust holes 21a, 21a, are arranged in the gas discharge paths 1b, 1b.

An arc extinguishing device 30, which is a general arc extinguishing structure, includes a well-known grid 31 and grid holders 32, 32 for holding them. That is, as shown in FIG. 7, the grid 31 is made of an iron plate and has a U-shaped groove, and an appropriate number of the grids 31 are overlapped and held by the grid holders 32, 32. Such an arc extinguishing device 30 attracts and extends the arc when both contacts 4 and 6 are opened and an arc is generated, and is divided and cooled by the grids 31, 31 and. The arc is cut off by increasing the arc voltage.

Further, the above-mentioned exhaust plate 21 has its exhaust holes 21a, 21a, ─ of arc gas so that the inter-electrode short circuit does not occur when the arc gas containing ionized ions is discharged to the outside of the circuit breaker. Squeeze the flow.

[0006]

[Problems to be solved by the device]

 The above-mentioned conventional circuit breaker has a complicated arc extinguishing device consisting of a plurality of grids and two grid holders, that is, an arc extinguishing structure, which is one of the obstacles in reducing the cost of the entire circuit breaker. ing.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a circuit breaker that can be manufactured at low cost by simplifying an arc extinguishing structure to reduce the number of parts and assembly steps. To provide.

[0008]

[Means for Solving the Problems]

 In order to solve such a problem, the circuit breaker according to claim 1 has a fixed contact having a fixed contact, a movable contact having a movable contact, and a fixed and movable opening / closing operation of the movable contact by a handle operation. An opening / closing mechanism section including a handle, a case made of an insulating material for accommodating and arranging at least each of the above-mentioned components, and having a gas discharge passage for communicating the accommodation space for accommodating both contacts with the outside, and a gas discharge passage. In a circuit breaker equipped with an exhaust plate with a gas exhaust hole, which is formed in a U shape with a facing piece and a connecting piece made of a magnetic material so as to attract the arc generated between the two contacts. In addition, an arc suction plate having an arc commutation portion is provided in the accommodation space, and the exhaust plate is made of a metal material and is close to the contact point of the first commutation portion and the commutation portion of the arc suction plate. Configuration with the second commutation part It is.

A circuit breaker according to a second aspect of the present invention includes a fixed contactor having a fixed contact, a movable contactor having a movable contact point, and a handle for performing fixed and opening / closing operations of the movable contact by a handle operation. An opening / closing mechanism portion including the above, at least the respective members described above are accommodated and arranged, and a case made of an insulating material having a gas discharge passage that communicates the accommodation space that accommodates both contacts with the outside, and the case are provided in the gas discharge passage. A circuit breaker having an exhaust plate having a gas exhaust hole, and two gas exhaust passages are provided in the disposing direction of both contacts, and each exhaust plate is made of a metal material and close to the contact. And a second commutation section that is close to each other.

[0010]

[Action]

 According to the structure of claim 1, the arc generated when the fixed and movable contacts are opened is attracted and extended by the arc suction plate, and the arc leg has the first commutation portion of the exhaust plate. And is divided by the second commutation portion of the exhaust plate and the commutation portion of the arc suction plate, and further cooled by the exhaust plate and the arc suction plate to increase the arc voltage.

According to the second aspect of the invention, the arc generated when both the fixed and movable contacts are opened is attracted and extended by the exhaust plate so that the arc leg has two legs. It can be transferred to the first commutation part of the exhaust plate, whereby it can be divided between the second commutation parts of both exhaust plates and can be cooled by the exhaust plate to increase the arc voltage.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The members having the same basic functions as those of the conventional one are designated by the same reference numerals.

Reference numeral 1 denotes a case, which is made of an insulating material such as phenol resin and is formed into a box shape having an opening on one side, and forms a housing together with an outside cover. FIG. 1 shows a state in which a cover for closing the opening of the case 1 is removed. The case 1 has a handle opening 1c formed on an upper wall surface thereof, and a fixed contact mounting portion 1d, a terminal plate mounting portion 1e and the like formed on the left and right side walls so as to be cut out from the opening end surface. The upper and lower walls and left and right side walls are not of uniform thickness, and the inner wall side should be designed appropriately with consideration given to the placement, fixing, positioning, etc. of the members to be housed, and the outer wall side with consideration of the attachment of terminal parts. Below the inside of the wall of Case 1, there is an accommodation space (space where fixed and movable contacts operate) 1a, which will be described later, and a thick part of Case 1 is used for fixing the cover. It has pilot holes 1f, 1f, for tapping screws and gas discharge paths 1b, 1b for communicating the accommodation space 1a with the outside. The case 1, that is, the housing, accommodates and arranges each member described later.

Reference numeral 3 denotes a fixed contact, which has a length extending from the inside to the outside of the case 1 when the fixed contact is attached to the fixed contact attachment portion 1d and is bent and formed. The fixed contact 3 has a fixed contact 4 fixed to one end located on the inner side of the case 1, and the other end on the outer side also serves as a terminal plate. Therefore, the terminal screw 23 is screwed.

Reference numeral 5 denotes a movable contact, which has a fixed contact 4 and a movable contact 6 for contacting and separating operation fixedly attached to one end located below, and the other end on the upper side rotatably supported by a handle described later. A spring bearing 5b of a reversing spring is provided in the middle part.

Reference numeral 7 denotes a handle, which is interlocked with the movable contactor 5 in cooperation with an opening / closing mechanism portion described later. The handle 7 has a lower rotation fulcrum 7a supported by the case 1, an upper operation portion 7b protruding from the handle opening 1c, and a cradle pressing portion 7c described later in the middle. The movable contact 5 is rotatably supported.

Reference numeral 8 denotes an opening / closing mechanism portion including the handle 7, which opens and closes the fixed and movable contacts 4 and 6 by operating the handle 7, and performs a trip operation when an abnormal current detecting means described later is activated. The opening / closing mechanism section 8 includes a cradle 9, a frame 10 supporting the cradle 9, a reversing spring 11 and the like. The frame 10 is supported by the case 1, and is formed by bending a rotation support portion 10a of the cradle 9 and a bimetal support piece 10b described later.

The cradle 9 has a substantially V-shape, one end of which is rotatably supported by the rotation supporting portion 10 a of the frame 10, and the other end of which is a locked portion which is locked by an abnormal current detecting means described later. 9a, a spring bearing 9b of a reversing spring and a pressed portion 9c corresponding to the pressing portion 7c of the handle 7 are provided in the middle portion. The reversing spring 11 has a coil shape, and is compressed and suspended between the movable contact 5 and the spring receivers 5b and 9b of the cradle 9. Therefore, the reversing spring 11 constantly biases the cradle 9 in the counterclockwise direction and biases the movable contact 5 in the contact contact direction or the contact open direction depending on the positions of the handle 7 and the cradle 9.

Reference numeral 12 is an abnormal current detecting means, which acts on the opening / closing mechanism 8 to perform a trip operation when an abnormal current flows in the electric path. The abnormal current detection means 12 is composed of a bimetal 13, a suction piece 14, a locking piece 15, an elastic piece 16, and the like. The base end of the bimetal 13 is fixed to the by-metal support piece 10b of the frame 10, the base end of the elastic piece 16 is fixed to the tip end, and the suction piece 14 is held in the middle part. The attracting piece 14 is a U-shaped magnetic plate material. The locking piece 15 has a long plate shape made of a magnetic plate material, and has a locking portion for locking the locked portion 9a of the cradle 9 at an appropriate position, and the base end is fixed to the tip of the elastic piece 16. It In this case, the locking piece 15 is located so as to face the end surface of the suction piece 14.

In the abnormal current detection means 12, when an overcurrent flows through the bimetal 13 and it is deformed, the locking piece 15 also moves accordingly, and a short-circuit current flows through the bimetal 13, causing a large magnetic flux in the adsorption piece 14. When flows, the locking piece 15 is immediately attracted to the end surface of the suction piece 14 and moves. That is, when an abnormal current such as an overcurrent or a short-circuit current flows in the electric circuit, the locked portion 9a of the cradle 9 is released from the locking portion of the locking piece 15 in order to perform trip operation.

Next, the arc extinguishing structure which is the main part of the present invention will be described. The arc extinguishing structure of the present invention mainly comprises an exhaust plate and an arc suction plate.

The exhaust plates 21, 21 are made of a metallic material, and as shown in FIG. 2, have an appropriate number of exhaust holes 21 a, 21 a, and are bent upward and downward toward the accommodation space 1 a. A first commutation section 21b, 21b and a second commutation section 21c, 21c that are connected in series are formed. The exhaust plates 21, 21 are mounted near the inner ends of the gas discharge paths 1b, 1b with the commutation parts 21b, 21c facing inward. The exhaust plates 21 and 21 are set so that the first commutation portions 21b and 21b are close to the contacts 4 and 6 in the open position. The second commutation parts 21c, 21c are set in association with an arc suction plate described later.

As shown in FIG. 2, the arc suction plate 22 is made of a magnetic material and is formed into a U-shape by the facing pieces 22a and 22a and the connecting piece 22b so as to attract the arc generated between the contacts 4 and 6. At the same time, the connecting piece 22b is extended to form arc commutation portions 22c, 22c. The arc suction plate 22 is located between the two exhaust plates 21 and 21 and is disposed in the accommodation space 1a. The commutation parts 22c, 22c are set to be close to each other in relation to the second commutation parts 21c, 21c of the exhaust plates 21, 21.

Reference numeral 24 denotes a terminal plate, and the terminal plate 24 and the bimetal 13 and the bimetal 13 and the movable contact 5 are electrically connected by a braided wire (not shown).

Next, the operation of the arc extinguishing structure will be described with reference to FIG. It should be noted that the trip operation when an abnormal current flows in the electric circuit is brought about by the abnormal current detection means 12, but it is omitted because it is not a main part of the present invention.

Immediately after the trip operation, as shown in (a), an arc A is generated between the contacts 4 and 6. This arc A is attracted and extended by the arc suction plate 22 as shown in (b), and its legs are extended from both contacts 4, 6 to the first of the exhaust plates 21, 21 so that the arc length is shortened. It is transferred to the commutation part 21b, so that it is divided between the second commutation parts 21c, 21c of the exhaust plates 21, 21 and the commutation part 22c of the arc suction plate 22, and the exhaust plates 21, 21 and the arc suction part are separated. It can be cooled by the plate 22 to increase the arc voltage. At this time, the arc gas containing ionized ions is discharged to the outside of the circuit breaker through the exhaust plates 21 and 21, but the exhaust holes 21a and 21a of the exhaust plates 21 and 21 flow into the arc gas flow. Since it is narrowed down, it is possible to prevent external short circuit between poles.

[0027] This one has an arc extinguishing structure formed by a simple shape arc suction plate and exhaust plate in place of a grid holder and a plurality of grids like the conventional arc extinguishing device, so that the number of parts and the number of assembling steps are reduced. Can be reduced.

Next, another embodiment of the present invention will be described with reference to FIG. In this example, the arc suction plate in the previous embodiment is omitted and the shape of the exhaust plate is changed. That is, one exhaust plate 21 has its second commutation portion 21c extended so as to be close to the second commutation portion 21c of the other exhaust plate 21. FIG. 4 corresponds to the state of FIG. 3 (c) in the previous embodiment.

Compared with the previous embodiment, this one has a smaller arc extinguishing ability due to the smaller number of arc divisions, but the grid holder and the plurality of grids can be omitted as in the conventional arc extinguishing device. Of course, the arc suction plate can be omitted, and since the arc extinguishing structure is formed only by the exhaust plate, the number of parts and the number of assembly steps can be further reduced.

[0030]

[Effect of device]

 In the circuit breaker according to claim 1, the arc generated when both the fixed and movable contacts are opened is attracted and extended by the arc suction plate, and the leg of the arc has the first commutation portion of the exhaust plate. And is divided by the second commutation part of the exhaust plate and the commutation part of the arc suction plate, and is cooled by the exhaust plate and the arc suction plate, so that the arc voltage can be increased, and thus the arc extinguishing structure can be achieved. This simplifies the process and reduces the number of parts and the number of assembly steps.

In the circuit breaker according to a second aspect of the present invention, the arc generated when both the fixed and movable contacts are opened is attracted and extended by the exhaust plate, and the arc leg has two exhaust plates. It is transferred to the first commutation part, so that it is divided between the second commutation parts of both exhaust plates, and it can be cooled only by the exhaust plates to increase the arc voltage, thus simplifying the arc extinguishing structure and parts. The number of points and the number of assembly steps can be further reduced.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention with a cover removed.

FIG. 2 is an exploded perspective view of a main part thereof.

3 (a) to (c) are explanatory views for explaining the behavior of an arc.

FIG. 4 shows another embodiment of the present invention and is an explanatory view for explaining the behavior of the arc.

FIG. 5 is a side view showing a conventional example without a cover.

FIG. 6 is a perspective view of the exhaust plate.

FIG. 7 is a perspective view of the arc extinguishing device.

[Explanation of symbols]

1 Case 1a Storage space for fixed and movable contacts provided in the case 1b Gas discharge path provided in the case 3 Fixed contact 4 Fixed contact 5 Movable contact 6 Movable contact 7 Handle 8 Open / close mechanism including handle 9 Open / close mechanism Cradle 10 Opening mechanism frame 11 Opening mechanism reversing spring 12 Abnormal current detecting means 13 Bimetal of abnormal current detecting means 14 Adsorption piece of abnormal current detecting means 15 Absorbing piece of abnormal current detecting means 16 Abnormal current detecting means Elastic plate 21 Exhaust plate 21a Exhaust plate exhaust hole 21b Exhaust plate first commutation part 21c Exhaust plate second commutation part 22 Arc suction plate 22a Arc suction plate facing piece 22b Arc suction plate connection piece 22c Arc Commutation part of suction plate A arc

Claims (2)

[Scope of utility model registration request] 1. A fixed contactor having a fixed contact, a movable contactor having a movable contact, an opening / closing mechanism section including a handle for opening and closing the fixed contact and the movable contact by a handle operation, and at least the respective members. While accommodating and arranging,
A circuit breaker provided with a case made of an insulating material having a gas discharge path for communicating the housing space for housing both contacts with the outside, and an exhaust plate having a gas exhaust hole arranged in the gas discharge path. In the above-mentioned, the arc suction plate having a commutation portion of the arc formed by a magnetic material in a U-shape with the facing piece and the connecting piece so as to attract the arc generated between the contact points is provided in the accommodation space, The plate is made of a metal material, and the first commutation portion is close to the contacts and the second commutation portion is close to the commutation portion of the arc suction plate
A circuit breaker that forms a commutation part. 2. A fixed contact having a fixed contact, a movable contact having a movable contact, an opening / closing mechanism section including a handle for opening and closing the fixed contact and the movable contact by operating a handle, and at least the above-mentioned members. While accommodating and arranging,
A circuit breaker provided with a case made of an insulating material having a gas discharge path for communicating the housing space for housing both contacts with the outside, and an exhaust plate having a gas exhaust hole arranged in the gas discharge path. 2. Two gas discharge passages are provided in the arrangement direction of both contacts, each exhaust plate is made of a metal material, and a first commutation portion adjacent to the contact and a second commutation portion adjacent to each other are formed. Circuit breaker characterized by.