JP5845698B2 - Circuit breaker - Google Patents

Description

  The present invention relates to a circuit breaker for wiring breakers, earth leakage breakers, and the like, and more particularly to a housing assembly structure of a main body case containing functional parts such as a current breaker and an opening / closing mechanism.

  As is well known, the circuit breaker mentioned above opens and closes the movable contact by operating the handle, and when an abnormal current (overcurrent) flows through the main circuit, the open / close mechanism is tripped to move the movable contact. Is opened and abnormal current is cut off. Here, the stationary contact corresponding to each phase of the main circuit, the movable contact held by the contact holder, the arc extinguishing device, the opening / closing mechanism for opening / closing the movable contact, its tripping mechanism, and the operation linked to the opening / closing mechanism The handle and various functional parts of the overcurrent detection device are incorporated in a main body case made of mold resin.

  On the other hand, when overcurrent is interrupted by the above circuit breaker, the metal melt and soot evaporated by the heat of the arc generated between the fixed / movable contacts of the main circuit scatters to the surroundings, opening and closing mechanism and tripping If it adheres to the movable part of the mechanism, there is a problem that its opening / closing operation and function are impaired.

  Therefore, as a countermeasure for the above problem, the main body case of the circuit breaker has a box-shaped lower case, a middle cover formed on the upper surface of the lower case by forming a recess partitioned by a partition wall in the center, and a middle An assembly structure that consists of a three-divided housing divided into a top cover that covers the upper surface of the cover, and that distributes and mounts each functional component to be incorporated into the lower case and middle cover as described below. The circuit breaker which becomes is known (for example, refer to Patent Document 1).

  In this circuit breaker, the lower case of the housing houses the current interrupting unit, the arc extinguishing device, and the overcurrent detection device, and the middle cover includes the operation handle, toggle link mechanism, and assembly of the trip mechanism. The opening / closing mechanism unit is housed to isolate the opening / closing mechanism unit from the current interrupting unit and the arc extinguishing device housed in the lower case. Further, the toggle link of the opening / closing mechanism unit passes through the bottom partition of the middle cover and is connected to the contact holder of the movable contact housed in the lower case.

  Next, an assembly structure of a conventional product corresponding to Patent Document 1 is shown in FIGS. 9 to 13, taking a three-pole type circuit breaker applied to a three-phase circuit as an example. First, in FIGS. 9 and 10, 1 is a main body case having a three-part structure of a lower case 2, a middle cover 3 and a top cover 4, 5 is a stationary contact formed integrally with a power supply terminal 5a, and 6 is a load. The side terminal, 7 is a movable contact facing the fixed contact 5, 8 is a rotary contact holder that holds the movable contact 7 in a swingable manner, 9 is an arc extinguishing device, and 10 is a toggle link mechanism 11. An opening / closing mechanism unit 14, which is an assembly combining the tripping mechanism 12 and the operation handle 13, is an overcurrent detection device, and includes a stationary contact 5, a movable contact 7, a contact holder 8, an arc extinguishing device 9, and an overload detection device. The current detection device 14 is accommodated and disposed at the bottom of the lower case 2, and the opening / closing mechanism unit 10 is a recess defined in the middle of the middle cover 3, separated from the current interrupting portion and arc extinguishing device 9 accommodated in the lower case 2. It is mounted and placed at 3a .

  Here, the assembly structure and the operation of the opening / closing mechanism unit 10 are described in detail in Patent Document 1. That is, in FIG. 9, the handle lever 13a of the operation handle 13 is pivotally supported by the assembly frame 10a of the opening / closing mechanism unit 10 in a swingable manner. The assembly frame 10a is connected to a latch 11a constituting a toggle link mechanism 11, a toggle link 11b composed of an upper link and a lower link spanned between the latch 11a and the contact holder 8, and a toggle link 11b. An open / close spring 11c stretched between a pin (toggle pin) and the operation handle 13, a trip cross bar 12a constituting a tripping mechanism 12 of the toggle link mechanism 11, and the latch 11a connected to the trip cross bar 12a. Each component such as a latch receiver 12b that is locked in the locked position is assembled. In the assembled state where the opening / closing mechanism unit 10 is mounted on the middle cover 3 and mounted on the lower case 2 as shown in FIG. 9, the lower link of the toggle link 11b penetrates the bottom partition wall 3b of the middle cover 3. It is connected to the contact holder 8 through the provided slit-shaped through hole.

  On the other hand, as shown in FIG. 11A, the lower case 2 of the main body case 1 has three internal spaces extending between the power source side and the load side through the pole interval wall 2a. The electrode chambers are partitioned into pole chambers, each of which has a fixed contact 5 corresponding to each pole of the main circuit (three-phase), a movable contact 7 held in a rotary contact holder 8, an eraser The arc device 9 and the overcurrent detection device 14 are accommodated (see FIG. 10).

  Further, as shown in FIG. 12, the contact holder 8 has a structure in which the holder portions 8a arranged side by side corresponding to each pole are connected by a shaft portion 8b. The contact holder 8 is as follows. And incorporated in the lower case 2. That is, a U-shaped bearing groove 2b into which the shaft portion 8b of the contact holder 8 is fitted is formed in the pole spacing wall 2a of the lower case 2 shown in FIG. After carrying the contact holder 8 across the bridge, the contact piece 15 having the shape shown in FIG. 11B is fitted into the bearing groove 2b of the pole interval wall 2a from above to rotate the contact holder 8. I am trying to hold it freely.

  On the other hand, a recess 3a partitioned by a partition as described above is defined at the center of the middle cover 3, and the opening / closing mechanism unit 10 having the assembly structure described above is mounted on the recess 3a. (See FIGS. 9 and 10). FIG. 13 is an external view of the opening / closing mechanism unit 10. In addition, in the recesses 3c defined on the left and right sides of the middle cover 3 across the mounting portion of the opening / closing mechanism unit 10, interior accessories such as auxiliary switches, alarm switches, voltage trip devices, undervoltage trip devices ( An undervoltage trip device 16 is shown in FIG. 14 as an example of an interior accessory.

  The undervoltage trip device 16 is a device for tripping the circuit breaker when the circuit voltage drops below a specified value. The case 16a including an electromagnet mechanism excited by the circuit voltage is shown in FIG. Further, an actuator 16b protruding toward the trip cross bar 12a of the tripping mechanism 12 and a reset lever 16c interlocking with the actuator 16b are provided. 14 and 15 show the positions of the actuator 16b and the reset lever 16c of the undervoltage trip device corresponding to each of the circuit breaker ON, TRIP, and RESET states.

  Further, after the circuit breaker trips in response to the operation of the undervoltage trip device 16, the undervoltage trip device 16 is returned to the reset state at the same time when the operation handle 13 is operated to reset the circuit breaker. As the operating means to be operated, as shown in FIG. 10, the handle lever 13a of the operation handle 13 is provided with a reset operation lever 17 protruding outward from its side wall and facing the tip of the reset lever 16c of the undervoltage trip device 16. Provided. As shown in FIG. 13, the reset operation lever 17 is made of a separate part from the handle lever 13a, and an engagement hole in which a projecting engagement pin 17a provided on the rear surface is drilled in the handle lever 13a. 13a-1 is press-fitted and fixed.

  Next, the trip operation and reset operation of the undervoltage trip device 16 will be described with reference to FIGS. FIG. 15A shows an ON state of the circuit breaker, and the reset operation lever 17 coupled to the handle lever 13a of the operation handle 13 is spaced apart to the side of the reset lever 16c of the undervoltage trip device. doing. In this state, when the circuit voltage falls below a specified value and the actuator 16b of the undervoltage trip device releases the trip mechanism 12 of the switching mechanism and the circuit breaker trips as shown in FIG. The lever 16c moves to the TRIP position and stops at this position. Thereafter, when the operation handle 13 is tilted to the RESET position so as to reset the circuit breaker, the reset operation lever 17 fixed to the operation handle 13 is moved to the reset lever 16c of the undervoltage trip device 16 as shown in FIG. Press to the right. As a result, the undervoltage trip device 16 returns to the reset state, the actuator 16b comes off from the trip mechanism 12 of the opening / closing mechanism unit 10, and the toggle link mechanism 11 also returns to the reset state.

JP 2005-228669 A

By the way, the conventional circuit breaker having the above-described casing structure has the following problems in its assemblability.
(1) As a structure for rotatably supporting the contact holder 8 accommodated in the lower case 2 of the main body case 1 as shown in FIGS. 11A and 11B, the pole interval wall 2a of the lower case 2 is used. An opening / closing mechanism unit 10 is mounted on the lower case 2 after a separate bearing piece 15 is fitted from above into the bearing groove 2b formed to support the shaft portion 8b of the contact holder 8 in a pivotal manner. The middle cover 3 is attached. For this reason, the number of parts and the number of assembling steps increase and the cost increases.
(2) In the assembly process of the circuit breaker, the ON / OFF / RESET operation of the operation handle 13 is performed at the assembly stage where the toggle link 11b is connected between the toggle link mechanism 11 of the switching mechanism unit 10 and the contact holder 8. In conjunction with this, it is checked whether the contact holder 8 and the movable contact 7 are correctly responsive.

  In this regard, in the conventional assembly structure, the middle cover 3 is mounted on the lower case 2 and accommodated in the lower case 2 when the toggle link mechanism 11 of the opening / closing mechanism unit 10 is coupled to the contact holder 8. The movable parts such as the movable contact 7 and the contact holder 8 arranged are covered with a middle cover 3. For this reason, it is difficult to visually confirm the operation status of the movable parts accommodated in the lower case 2 when confirming the operation of the opening / closing mechanism described above.

  In addition, when the top cover 4 is put on the middle cover 3 on which the switching mechanism unit 10 is mounted in the circuit breaker assembly process, the reset operation lever 17 (see FIG. 5) is fixed to the handle lever 13a of the operation handle 13 and protrudes to the side. 10)), the mounting position of the reset operation lever 17 shifts or drops off from the operation handle 13 frequently occurs, causing the assembly workability to deteriorate. .

  The present invention has been made in view of the above points, and its object is to solve the above-mentioned problems, reduce the number of parts, improve the assembly workability, and further, the internal state of the lower case with the cover removed in the assembly process. It is an object of the present invention to provide a circuit breaker having an improved housing assembly structure so that the checking operation of the opening / closing mechanism and the contact operation can be performed while visually checking.

In order to achieve the above object, according to the present invention, a main body case having a two-part structure of a lower case and a cover and whose inner space is partitioned into a plurality of poles via a pole interval wall is provided for each pole. A corresponding stationary contact, a movable contact held by a rotating contact holder facing the stationary contact, and a current interrupting unit comprising an arc extinguishing device;
An open / close mechanism unit comprising an assembly of an operation handle, a toggle link mechanism, and a tripping mechanism thereof, wherein the toggle link is connected to the contact holder, and a circuit breaker equipped with an overcurrent detection device,
In the case where the current interruption part and the overcurrent detection device are accommodated in the lower case and the cover is formed with a recess for accommodating the interior accessories arranged side by side on the operation handle,
Fitted into the right and left side edges to be integrally formed and independent parts, bearings groove of the contact holder the bearing portion is formed notch in pole pitch wall of the lower case of the base plate bearing portion for supporting said contact holder A holder bearing member that is installed only on the center pole, and the opening / closing mechanism unit is mounted on the holder bearing member and fixed to the lower case, and the toggle link mechanism of the opening / closing mechanism unit is connected to the contactor. The holder is connected to the center pole holder (claim 1).

  The base plate of the holder bearing member includes a bottom partition wall and an upright partition wall that isolates the switching mechanism unit from the contact holder of the current interrupting unit and the arc extinguishing device, and the bottom partition wall includes a toggle of the switching mechanism unit. A slit hole through which the link mechanism is passed is formed (claim 2).

  Further, the bearing portion formed on the side edge of the holder bearing member carries a reset operation lever that is fixed to the outer surface of the handle lever of the operation handle and resets the interior accessory stored in the cover of the main body case. An arcuate guide wall portion that guides and supports the swing path is formed.

According to the said structure, there can exist the following effect.
In other words, the holder bearing member made as an independent part has a bottom partition wall and an upright that isolates the opening / closing mechanism unit mounted on the holder bearing member from the contact holder and arc extinguishing device housed in the lower case of the main body case. A partition wall, a pair of bearing portions projecting from the left and right edges of the bottom partition wall, and a guide wall portion for guiding and supporting a reset operation lever attached to the operation handle are integrally formed. This
(1) In the assembled state of the circuit breaker in which the opening / closing mechanism unit is mounted on the holder bearing member and assembled on the center pole of the lower case and the cover is attached to the lower case, the partition wall of the holder bearing member is separated. The opening / closing mechanism unit is separated from the current interrupting unit and the arc extinguishing device accommodated in the lower case. As a result, the body case is simplified compared to the conventional structure to reduce the cost of parts, and the metal melt generated in the current interrupting part due to the arc heat when the overcurrent current is interrupted is opened / closed or tripped. Can be prevented from adhering to the movable part.
(2) In addition, the operation check operation of the switching mechanism and contact mechanism performed in the circuit breaker assembly process is performed with the contact holder, movable contact, etc. housed in the lower case with the cover of the main body case removed. It is possible to check the operation by operating the operation handle while visually checking the movable part. Thereby, the workability of the operation check can be greatly improved as compared with the conventional structure.
(3) Furthermore, the bearing portion of the holder bearing member is formed with a guide wall portion that guides and supports the reset operation lever that is fixed to the side wall surface of the handle lever of the operation handle, facing the interior accessory housed in the cover. As a result, when attaching the cover to the lower case of the main body case in the assembly process of the circuit breaker, prevent the assembly troubles that the internal partition wall of the cover hits and the mounting position of the reset operation lever shifts or falls off Can do.

It is a disassembled perspective view of the main components of the circuit breaker by the Example of this invention. FIG. 2 is a side cross-sectional view illustrating an assembly structure of a circuit breaker corresponding to FIG. 1. FIGS. 2A and 2B are assembly views of the opening / closing mechanism unit in FIG. 1, in which FIG. 1A is an assembled state in which the opening / closing mechanism unit is mounted on a holder bearing member, and FIG. It is a block diagram of the holder bearing member in FIG. 1, Comprising: (a), (b) is an external appearance perspective view and a side view, respectively. It is an overhead view showing the state which attached the holder bearing member to the lower case in FIG. FIG. 2 is a perspective sectional view taken along the line AA of the cover in FIG. 1. It is a perspective sectional view in alignment with arrow BB of the cover in FIG. It is a bird's-eye view showing the state where the interior accessory was stored in the cover of the main body case. It is side view sectional drawing showing the assembly structure of the conventional circuit breaker (circuit breaker for wiring). FIG. 10 is an exploded perspective view of FIG. 9. It is a block diagram of the lower case in FIG. 10, (a) is an overhead view of the state which attached the bearing piece of the contactor holder to the lower case, (b) is an expanded perspective view of a bearing piece. It is an external appearance perspective view of the contact holder in FIG. FIG. 11 is an assembly structure diagram of the opening / closing mechanism unit in FIG. 10. It is a side view of the interior accessory (undervoltage trip device) accommodated in the middle cover of FIG. It is operation | movement explanatory drawing of the undervoltage trip apparatus shown in FIG. 14, Comprising: (a), (b), (c) shows each state of ON, TRIP, and RESET each linked | related with the switching mechanism unit of a circuit breaker. FIG.

Hereinafter, embodiments of the present invention will be described based on the examples shown in FIGS. In addition, in the figure of an Example, the same code | symbol is attached | subjected to the same member corresponding to FIG. 9, and the description is abbreviate | omitted.
The circuit breaker of the illustrated embodiment has basically the same configuration as the conventional circuit breaker shown in FIG. 9, but the support structure of the main body case 1 and the opening / closing mechanism unit 10 mounted on the main body case 1 is the same. Different from conventional ones.

  That is, in the conventional structure, the main body case 1 has a three-part structure of the lower case 2, the middle cover 3, and the top cover 4. The opening / closing mechanism unit 10 is mounted in the recess of the middle cover 3 and accommodated in the lower case 2. It isolate | separates between a interruption | blocking part and an arc-extinguishing apparatus (refer FIG. 10).

  On the other hand, in the illustrated embodiment, as shown in FIGS. 1 and 2, the main body case 1 is constituted by a two-part structure of the lower case 2 and the cover 19, and the conventional case is placed above the central pole of the lower case 2. The holder bearing member 18 having a structure different from that of the holder bearing piece 15 (see FIG. 11) is mounted, and the opening / closing mechanism unit 10 is mounted on the holder bearing member 18 so as to be between the current interrupting unit and the arc extinguishing device. Next, a detailed structure of the holder bearing member 18 and the cover 19 will be described.

  First, the structure of the holder bearing member 18 is shown in FIGS. That is, the holder bearing member 18 has a structure in which a pair of bearing portions 18a are formed so as to protrude from both the left and right sides of the bottom partition wall 18b, integrally with a base plate having an L-shaped cross section composed of the bottom partition wall 18b and the standing partition wall 18c. Then, as shown in FIG. 5, the bearing portion 18 a is fitted into the bearing groove 2 b formed by notching the pole interval wall 2 a of the lower case 2 from above, and then, as shown in FIGS. 3 (a) and 3 (b). Thus, the opening / closing mechanism unit 10 is mounted on the holder bearing member 18. In this assembled state, the toggle link 11b of the opening / closing mechanism unit 10 is connected to the center pole of the contact holder 8 through the slit hole 18b-1 formed in the bottom partition wall 18b of the holder bearing member 18, and the bottom surface of the lower case 2 is connected. A fastening bolt (not shown) inserted from the side is screwed into a screw seat 10b formed on the frame 10a of the opening / closing mechanism unit 10, and the opening / closing mechanism unit 10 and the holder bearing member 18 are fastened together and fixed to the lower case 2. I am doing so.

In addition, an arcuate guide wall portion that carries a reset operation lever 17 fixed to the lever side surface of the operation handle 13 and guides and supports it along the swing path on the upper edge of the bearing portion 18a of the holder bearing member 18. 18d is formed. The structure and function of the reset operation lever 17 are described in FIGS. Further, the bottom partition wall 18b of the holder bearing member 18 is provided with a slit hole 18b-1 (through the lower arm of the toggle link 11b connecting the opening / closing mechanism unit 10 and the contact holder 8 accommodated in the lower case 2). FIGS. 4 (a) refer) is bored in the left and right bottom partition wall 18 b.

  Next, the structure of the cover 19 that covers the upper surface of the lower case 2 is shown in FIGS. That is, the cover 19 is provided with a top cover 19a on the upper surface, a space 19b surrounding the opening / closing mechanism unit 10 in the center of the cover body, and interior accessories of a circuit breaker on the left and right of the space 19b. A pocket-like recess 19c for accommodating (such as the undervoltage trip device 16 in FIG. 14) is formed, and the void 19b is open downward. In addition, 19d is a leg piece that overlaps the outside of the bearing portion 18a of the holder bearing member 18, and 19e and 19f are partition walls that cover the end surfaces on the power supply side and the load side, respectively. FIG. 8 shows a state in which the undervoltage trip device 16 is loaded as an interior accessory in the pocket-shaped recess 19c of the cover 19 with the cover 19 attached to the lower case 2.

  According to the above assembly structure, the bottom partition 18b, the standing partition 18c, and the cover of the holder bearing member 18 are provided between the contact mechanism of the current interrupter accommodated in the lower case 2 and the arc-extinguishing device 9 and the opening / closing mechanism unit 10. 19 is isolated. Therefore, similar to the conventional circuit breaker shown in FIG. 9, the metal melt and soot generated in the current breaker and the arc extinguishing device due to the arc heat at the time of overcurrent interruption is scattered, and the switching mechanism and tripping It is possible to prevent adhesion to the movable part of the mechanism. Moreover, the main body case 1 has a two-part structure of the lower case 2 and the cover 19, and the main body case 1 is simplified and the parts cost can be reduced as compared with a conventional product having a three-part structure. The holder bearing member 18 is not limited to a resin molded product, and a die-cast product made of a metal material, for example, can also be adopted.

  Further, the switching mechanism unit 10 is mounted on the central pole of the lower case 2 on which components such as a contact mechanism and an arc extinguishing device are arranged via a holder bearing member 18, and the toggle link 11 b is connected to the contact holder 8. In the assembly stage of the circuit breaker connected by the operation handle 13 before the cover 19 is attached, the operation handle 13 is operated while visually confirming the movement of the movable parts such as the movable contact 7 and the contact holder 8 arranged in the lower case 2. It is possible to check the opening and closing operation. Thereby, the workability can be greatly improved compared to the case of checking the opening / closing operation in the assembled state in which the lower cover 2 is covered with the middle cover 3 (see FIG. 10) as in the conventional product.

  Further, when the opening / closing mechanism unit 10 is mounted on the holder bearing member 18 and assembled to the lower case 2, the reset operation lever 17 fixed to the lever side surface of the operation handle 13 is formed on the bearing portion 18 a of the holder bearing member 18. It is carried on an arcuate guide wall 18d. Therefore, even if the inner partition wall of the cover 19 hits the reset operation lever 17 when the cover 19 is put on the lower case 2 from this state, the mounting position is shifted or dropped, and the workability of the assembly process is prevented. Can improve.

DESCRIPTION OF SYMBOLS 1 Main body case 2 Lower case 2a Polar space | interval wall 2b Bearing groove 5 Fixed contact 7 Movable contact 8 Contactor holder 8a Holder part 8b Shaft part 9 Arc extinguishing device 10 Opening / closing mechanism unit 11 Toggle link mechanism 12 Tripping mechanism 13 Operation handle 13a Handle lever 14 Overcurrent detection device 16 Interior accessory (Undervoltage trip device)
17 Reset operation lever 18 Holder bearing member 18a Bearing portion 18b Bottom partition wall 18c Standing partition wall 18d Reset operation lever guide wall portion 19 Cover 19b Opening / closing mechanism unit storage space 19d Recess for storing interior accessories

Claims (3)

The main body case, which has a two-part structure of the lower case and the cover, and whose internal space is partitioned into a plurality of poles via a pole interval wall, has a fixed contact corresponding to each pole, facing the fixed contact A movable contactor held in a rotating contactor holder, and a current interrupting unit comprising an arc extinguishing device;
An opening / closing mechanism unit comprising an assembly of an operation handle, a toggle link mechanism, and a tripping mechanism thereof, and connecting the toggle link to the contact holder;
A circuit breaker equipped with an overcurrent detection device,
In the case where the current interruption part and the overcurrent detection device are accommodated in the lower case and the cover is formed with a recess for accommodating the interior accessories arranged side by side on the operation handle,
Fitted into the right and left side edges to be integrally formed and independent parts, bearings groove of the contact holder the bearing portion is formed notch in pole pitch wall of the lower case of the base plate bearing portion for supporting said contact holder A holder bearing member that is installed only on the center pole, and the opening / closing mechanism unit is mounted on the holder bearing member and fixed to the lower case, and the toggle link mechanism of the opening / closing mechanism unit is connected to the contactor. A circuit breaker connected to the center pole holder of the holder.   2. The circuit breaker according to claim 1, wherein the base plate of the holder bearing member includes a bottom partition wall and an upright partition wall that separates the switching mechanism unit from the contact holder of the current interrupting unit and the arc extinguishing device, and A circuit breaker characterized in that a slit hole through which a toggle link mechanism of an opening / closing mechanism unit is passed is formed in a bottom partition wall.   The circuit breaker according to claim 1 or 2, wherein the interior accessory stored in the cover of the main body case is fixed to the outer surface of the handle lever of the operation handle on the bearing portion formed on the side edge of the holder bearing member. A circuit breaker characterized in that an arcuate guide wall portion is formed which carries a reset operating lever to be guided and supported on its swing path.