JP3959888B2 - Circuit breaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit breaker for a circuit breaker for wiring or a switch for starting and stopping an electric motor, and overcurrent protection, and more particularly to its assembly structure.
[0002]
[Prior art]
First, an example of a circuit breaker provided with a bridge-type two-contact main circuit contact is shown in FIGS. 7 (a) and 7 (b). In the figure, 1 is a resin-molded main body case comprising a combination of a lower case 1a and an upper cover 1b, 2 is a main circuit terminal on the power supply side corresponding to each phase, 3 is a main circuit terminal on the load side, and 4 is a main circuit terminal on the load side. One fixed contact connected to the conductor of the circuit terminal 2, 5 is the other fixed contact, 6 is a movable contact that bridges the fixed contacts 4 and 5, 7 is a movable contact holder, 7a is a contact spring, 8 Is a cage that guides and supports the movable contact holder 7 in the opening and closing direction, 9 is an arc extinguishing device, 10 is an opening and closing lever that drives the movable contact 6 to the open position, 11 is an opening and closing mechanism that is linked to the opening and closing lever 10, and 12 Is a manual operation handle, 13 is an overcurrent that combines a bimetallic thermal trip device 13a that operates in response to an overload current, and an electromagnetic trip device 13b that operates instantaneously in response to a short circuit current. Trip device, overcurrent Release device 13 is connected to the main circuit interposed in series between the main circuit terminal 3 of the fixed contact 5 and the load side. The operating piece 13c of the overcurrent tripping device 13 is linked to the latch of the opening / closing mechanism 11 via a trip cross bar or the like.
[0003]
The operation of such a circuit breaker is well known. When the operation handle 12 is turned on, the opening / closing lever 10 is retracted, and the movable contact 6 is lifted together with the holder 7 by the urging of the contact spring 7a, and the fixed contact 4 Bridge between 5 and 5. In this closed state, the main circuit current flows from the main circuit terminal 2 on the power source side to the fixed contact 4 → the movable contact 6 → the fixed contact 5 → the overcurrent trip device → the main circuit terminal 3 on the load side. When the operation handle 12 is operated to the OFF position, the opening / closing lever 10 swings clockwise via the opening / closing mechanism 11 to push down the movable contact holder 7. Thereby, the movable contact 6 is separated from the fixed contacts 4 and 5, and the main circuit contact is opened. On the other hand, when an overload current or a short-circuit current flows in the main circuit, the latch of the opening / closing mechanism unit 10 is released by the operation of the overcurrent tripping device 13, whereby the opening / closing lever 10 is rotationally driven to open the movable contact 6. Cut off the main circuit current.
[0004]
[Problems to be solved by the invention]
By the way, the circuit breaker having the above-described conventional structure has the following problems with respect to the change in the specifications regarding the productivity and the rated items of the overcurrent tripping device.
That is, in the assembly line for manufacturing the circuit breaker shown in FIG. 7, the main circuit components, the open / close lever, and the open / close in each subsequent assembly process based on the lower case 1a of the main body case 1 supplied to the assembly line first. The mechanical part and the specified overcurrent tripping device of the specified specifications are assembled in order, and finally the upper cover is attached to complete the product. In addition, the assembled products are subjected to various operation tests in the inspection process, non-accepted products are transferred to the adjustment process, the body case cover is removed, and the internal components are adjusted for positional deviation, adjusted, and After replacing defective parts with good ones, they are reassembled.
[0005]
However, in the assembly structure in which all the parts are sequentially assembled based on the main body case 1 as described above, many assembly processes are required from the introduction of the parts to the completion of the product, and it takes much time for the assembly work. For example, when a product with an urgent delivery date is required, it becomes difficult to handle production. Furthermore, when assembling circuit breakers with various specifications with different rated ranges and operation handles on the same assembly line, the types of assembly parts are increased and the assembly process and work are complicated. In particular, the assembly of the overcurrent trip device and the opening / closing mechanism section requires careful work for assembly because misalignment of the assembly position and poor adjustment greatly affect the switching operation and tripping operation characteristics.
[0006]
In addition, for the assembled product, for example, when there is a request from the user to change the specifications of the overcurrent trip device, the assembled circuit breaker is disassembled and replaced with parts of different specifications and then reassembled. Time-consuming work is required. Furthermore, even if it is necessary to change the specifications of the overcurrent protection function for a circuit breaker that is in operation due to changes in the electrical equipment at the customer's site (there are many such cases), the same as above Since replacement requires disassembly and reassembly of the circuit breaker, it cannot be easily handled by the user.
[0007]
The present invention has been made in view of the above points, and its purpose is to solve the above problems, improve the assembly of the circuit breaker body, improve the productivity of the product, and also change the specification of the rating. An object of the present invention is to provide a circuit breaker having an improved assembly structure so that it can be flexibly accommodated.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a main circuit terminal for each phase, a stationary contact, a movable contact, an arc extinguishing unit, a movable contact switching mechanism, and an overcurrent trip device are provided on the main body case. In the circuit breaker built-in, the switching mechanism unit and the overcurrent trip device are assembled in independent unit cases to form the switching mechanism unit and the overcurrent trip unit, and then each unit is connected to the main circuit. embedded assembly is housed in the main body casing assembled parts Rutotomoni, the opening and closing mechanism unit, and the overcurrent tripping the unit case of the unit, the fixed contact bridge絡形2 contacts scheme, and the terminal together and as for the overcurrent tripping unit bonded directly to the connection terminals of the fixed contacts, and overcurrent tripping device main circuit terminals in the unit case structure To (claim 1).
[0009]
According to such a configuration, the switching mechanism unit and the overcurrent tripping unit are independently assembled in an assembly process different from the assembly of the circuit breaker body, and the parts are adjusted and the operation test is performed in units of the unit. Can do. In the assembly line of the circuit breaker body, it is only necessary to store the already assembled switching mechanism unit and overcurrent trip unit in the case body, which greatly reduces the number of assembly steps for the circuit breaker body and increases product productivity. Improvement can be achieved. In addition, the overcurrent tripping unit can be prepared and prepared in advance with various specifications with different rated currents, so that sudden changes in specifications can be flexibly handled by simply replacing the units.
[0014]
Further, as in the invention described in claim 2, the main body case is provided with a main circuit terminal for each phase, a stationary contact, a movable contact, an arc extinguishing unit, a movable contact opening / closing mechanism, and an overcurrent trip device. In the built-in circuit breaker, the switching mechanism and the overcurrent trip device are assembled in independent unit cases to form the switching mechanism unit and the overcurrent trip unit, and then each unit is replaced with the main circuit component. It is housed and assembled in the assembled main body case, and an insulating contact holder that holds the movable contacts of each phase in a lump is inserted in the space defined between the main body case and each unit case. Guide and support in the contact opening and closing direction .
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples shown in FIGS. In addition, in the figure of each Example, the same code | symbol is attached | subjected to the same member corresponding to FIG. 7, and the description is abbreviate | omitted.
[0016]
[Example 1]
FIG. 1 shows an embodiment of the present invention. In this embodiment, the overcurrent tripping device 13 and the opening / closing mechanism section 11 are assembled in unit cases 14 and 15 as independent resin molded products to constitute an opening / closing mechanism unit and an overcurrent tripping unit. Each unit is housed side by side in the lower case 1a of the main body case 1 incorporating the assembly of the movable contact 6 and the arc extinguishing device 9, and the unit cases 14 and 15 are accommodated in the upper cover 1b of the main body case 1. It becomes the composition covered in common. The unit cases 14 and 15 are clamped and fixed at predetermined positions by, for example, covering the lower case 1a of the main body case 1 with the upper cover 1b and fastening them with bolts.
[0017]
In this embodiment, the fixed contact 5 is integrally formed on the bottom wall portion of the unit case 14, and one end of the fixed contact 5 is connected to the connection terminal of the overcurrent tripping device 13 in the unit case. The main circuit terminal 3 on the load side is directly joined to the other connection terminal of the overcurrent tripping device 13. The operating piece 13c of the overcurrent tripping device 13 passes through a hole opened in the side wall of the unit case 14 and is pulled out to the side, and the opening / closing mechanism unit 11 is passed through the side wall opening of the unit case 15 in the illustrated assembled state. It is linked with the latch. On the other hand, the unit case 15 of the opening / closing mechanism 11 also has a fixed contact 4 connected to the conductor of the main circuit terminal 2 on the power source side inserted in the bottom wall portion, and is integrally incorporated, and is fixed at the assembly position. The contacts 4 and 5 are opposed to the bridge-shaped movable contact 6.
[0018]
On the other hand, the contact holder 7 of the movable contact 6 incorporated in the lower case 1a of the main body case 1 is a resin molded product. As shown in FIG. 5, the movable contact 6 of each phase (in the illustrated example, three phases). Are held together with the contact spring 7a and the support frame 7b of the contact spring. Then, as described above, in the assembled state in which the unit cases 14 and 15 are housed in the lower case 1a of the main body case 1, the lower case 1a and the unit cases 14 and 15 are connected to each other as shown in the detailed view of FIG. The contact holder 7 is guided and supported so as to be movable up and down in a pocket-shaped space defined therebetween. Note that the open / close lever 10 protruding from the open / close mechanism 11 at this storage position faces the upper surface of the holder 7. With this configuration, the cage 8 for supporting the holder guide incorporated in the lower case 1a in the conventional structure shown in FIG. 7 becomes unnecessary, and the number of parts and the number of assembling steps can be reduced accordingly.
[0019]
FIG. 2 shows an application example in which the shape of the unit case 14 of the overcurrent tripping unit described above is slightly different from that in FIG. That is, in the configuration of FIG. 1, the peripheral wall of the unit case 14 is stored so as to be completely surrounded by the lower case 1 a, but in the configuration of FIG. 2, the terminal cover for the main circuit terminal 3 on the load side is the unit case 14. The outer peripheral wall of the unit case 14 is overlapped between the lower case 1a and the upper cover 1b of the main body case 1 so as to serve as the outer wall of the circuit breaker case.
[0020]
[Example 2]
Next, an assembly structure of another embodiment of the present invention is shown in FIG. In this embodiment, the overcurrent tripping device 13 and the opening / closing mechanism 11 are assembled in independent unit cases 14 and 15, and each unit case is stored side by side in the lower case 1 a of the main body case 1. However, the upper cover 1b of the main body case 1 is further divided into left and right parts, and the divided covers 11b-1 and 11b-2 are respectively overcurrent tripping devices. 13 unit cases 14 and a unit case 15 of the opening / closing mechanism 11 are attached.
[0021]
And in the assembly state of the solid line which assembled each unit in the main body case 1 from the position of the dotted line in the figure, the divided covers 11b-1 and 11b-2 are connected to the left and right to form an outer cover of the circuit breaker case. ing.
[0022]
In this embodiment, as in the first embodiment, the fixed contacts 4 and 5 and the main circuit terminals 2 and 3 are integrally incorporated in the unit cases 14 and 15, and the movable contacts are assembled in the assembled state. The holder 7 is guided and supported between the lower case 1 and the unit cases 14 and 15 in the opening / closing operation direction of the movable contact 6.
[0023]
According to this configuration, the divided covers 11b-1 and 11b-2 are assembled to the unit cases 14 and 15 in the assembly process of the overcurrent trip unit and the switching mechanism unit different from the assembly process of the circuit breaker body. I can leave. As a result, in the assembly process of the circuit breaker body, the step of assembling the cover after the units are assembled in the lower case 1b of the main body case 1 can be omitted. The mechanism can be protected.
[0024]
Example 3
Then a further different embodiment of the present invention FIG. 4 (a), the shown (b). In this embodiment, the following points are different from the first and second embodiments. That is, the overcurrent tripping unit is attached to the lower case 1a of the main body case 1 so as to be detachable as needed in a cassette type, and an independent dedicated cover 14a is attached to the unit case 14. . Reference numeral 16 denotes a dial for adjusting the rated current of the overcurrent tripping device 13 provided in the dedicated cover 14a.
[0025]
In order to lock and fix the unit case 14 to the lower case 1a when the overcurrent tripping unit is stored and set in the main body case 1 from the dotted line position shown in the figure, for example, an engaging claw is formed on the unit case 14. An engaging groove can be formed in the lower case 1b opposite to this and both can be fixed in a crossing manner. Further, in a state where the overcurrent trip unit is housed and set in the main body case, the load side main circuit terminal 3 built in the lower case 1a of the main body case 1 and the connection terminal of the overcurrent trip device 13 are connected. In this embodiment, a socket-type connector 3a opened upward is formed at the inner end of the main circuit terminal 3 and is inserted into the connection terminal of the overcurrent tripping device 13 so as to face this. The connector pin 13d is formed, and the connector 3a and the connector pin 13d are fitted together at the unit storage position to form a conductive path.
[0026]
On the other hand, in the upper cover 1b of the main body case 1, a unit insertion hole 1b-3 is opened in advance according to the loading position of the overcurrent tripping unit, and the lower case 1a of the main body case 1 is assembled in the circuit breaker body assembly process. After assembling the opening / closing mechanism unit and the upper cover 1b, the assembly of the overcurrent tripping unit is inserted into the unit insertion hole 1b-3 opened in the upper cover 1b from the dotted line position shown in the figure and stored in place. Like to do.
[0027]
According to such a configuration, it is possible to remove the overcurrent trip unit as needed without disassembling the breaker body even after assembly of the product or at the site of use at the delivery destination. As a result, even if the user requests a change in the rated current specification after product assembly or delivery, it can be handled immediately by simply replacing the overcurrent tripping unit with a different specification.
[0028]
【The invention's effect】
As described above, according to the configuration of the present invention, the switching mechanism unit and the overcurrent tripping unit are individually assembled in an assembly process different from the assembly of the circuit breaker body, and the unit is a unit. Adjustments and operation tests. Therefore, in the breaker body assembly line, it is only necessary to store and set the switching mechanism unit and overcurrent trip unit that have already been assembled and adjusted in the case body, which greatly reduces the number of assembly steps for the breaker body. Product productivity can be improved. Moreover, the overcurrent tripping unit can be prepared and prepared in advance with various specifications with different rated currents, so that it is possible to flexibly respond to the request for changing the specifications by simply replacing the units.
[Brief description of the drawings]
FIG. 1 is a structural cross-sectional view of a circuit breaker corresponding to Embodiment 1 of the present invention. FIG. 2 is a structural cross-sectional view of a circuit breaker representing an application example of Embodiment 1 of the present invention. FIG. 4 is a structural diagram of a circuit breaker corresponding to Example 3 of the present invention, (a) is a top view, and (b) is a longitudinal sectional view. 5 is a front view of the movable contact holder in FIGS. 1 to 4. FIG. 6 is a side view of the movable contact holder in FIG. 5 incorporated in a circuit breaker body. FIG. It is the block diagram of the conventional example of the circuit breaker, (a) is a sectional view of the entire configuration, (b) is an enlarged view of the movable contact holder part in (a) Figure 【Explanation of symbols】
1 Body case 1a Lower case 1b Upper cover 1b-1 Divided cover 1b-2 for overcurrent trip unit Divided cover 1b-3 for opening / closing mechanism unit Insertion hole 2 for overcurrent trip unit 2 Main circuit terminal (power supply side)
3 Main circuit terminal (load side)
3a Connector sockets 4, 5 Fixed contact 6 Movable contact 7 Movable contact holder 9 Arc extinguishing device 11 Opening and closing mechanism 12 Operation handle 13 Overcurrent trip device 13a Thermal trip device 13b Electromagnetic trip device 13d Connector Pin 14 Unit case 14a for overcurrent trip unit Unit cover 15 Unit case for opening / closing mechanism unit

Claims (2)

In a circuit breaker in which a main circuit terminal of each phase, a stationary contact, a movable contact, an arc extinguishing unit, a movable contact switching mechanism, and an overcurrent trip device are incorporated in the main body case, the switching mechanism, and closing mechanism unit incorporates overcurrent tripping device to each separate unit case, and overcurrent tripping on configuring the unit, assembled housed in the body case each unit assembled with the main circuit components Rutotomoni, wherein Each of the switching mechanism unit and the overcurrent trip unit unit case is integrated with each bridge contact type 2-contact type fixed contact and its terminal, and for the overcurrent trip unit, a fixed contact, And a circuit breaker characterized in that the main circuit terminal is directly joined to the connection terminal of the overcurrent trip device in the unit case. In a circuit breaker in which a main circuit terminal of each phase, a stationary contact, a movable contact, an arc extinguishing unit, a movable contact switching mechanism, and an overcurrent trip device are incorporated in the main body case, the switching mechanism, and An overcurrent trip device is assembled in each independent unit case to form an open / close mechanism unit and an overcurrent trip unit, and then each unit is housed and assembled in a main body case assembled with main circuit components. A contact holder made of an insulator that collectively holds the movable contacts is interposed in a space defined between the main body case and each unit case, and is guided and supported in the contact opening / closing direction. Circuit breaker.

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