JP3997664B2 - Circuit breaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit breaker for wiring, or a circuit breaker for starting / stopping an electric motor, a motor breaker for overcurrent protection, and the like, and more particularly to an assembly structure of a main body case.
[0002]
[Prior art]
First, an example of a circuit breaker for a three-phase circuit provided with a bridge-type two-contact main circuit contactor is shown in FIG. In the figure, 1 is a resin-molded main body case having a three-part structure of a lower case 1a, an upper cover 1b, and an intermediate case 1c, 2 is a main circuit terminal on the power supply side corresponding to each phase, and 3 is a load side The main circuit terminal 4 is one fixed contact connected to the conductor of the main circuit terminal 2, 5 is the other fixed contact, 6 is a movable contact that bridges the fixed contacts 4 and 5, and 7 is a movable contact holder. 7a is a contact spring, 8 is a cage for guiding and supporting the movable contact holder 7 in the opening and closing direction, 9 is an arc extinguishing plate, 10 is an opening / closing lever for driving the movable contact 6, and 11 is a toggle type including the opening / closing lever 10. Contact opening / closing mechanism, 12 is a manual operation handle, 13 is an electromagnetic trip device 13a that operates instantaneously in response to a short-circuit current, etc. Overcurrent pulling combined with device 13b A and device, the overcurrent tripping device 13 is 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 contact opening / closing mechanism 11 via a trip cross bar and a latch receiver.
[0003]
Here, a contact mechanism for each phase and an arc extinguishing plate are incorporated side by side in the lower case 1a of the main body case 1, and each phase is insulated by a phase interval wall (barrier) integrally formed in the case. Isolated. Further, the upper cover 1b is also integrally formed with phase interval walls at the front and rear ends thereof to insulate and isolate the main circuit terminals 2 of each phase. Further, the intermediate case 1c is equipped with an opening / closing mechanism 11 and an overcurrent tripping device 13, and is assembled on the lower case 1a in a stacking manner.
[0004]
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 , 5 is closed. 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 13 → the main circuit terminal 3 on the load side. Further, when the operation handle 12 is reversed and moved to the OFF position, the contact opening / closing mechanism 11 drives the opening / closing lever 10 clockwise 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 through the main circuit, the latch of the contact opening / closing mechanism 10 is released by the operation of the overcurrent tripping device 13, whereby the opening / closing lever 10 opens the movable contact 6 in the opening direction. Drive to cut off main circuit current.
[0005]
[Problems to be solved by the invention]
As described above, the main body case 1 of the circuit breaker assembled in three parts, ie, the lower case 1a, the upper cover 1b, and the intermediate case 1c, can be assembled in a manner that can be adapted to the automatic assembly method by the robot, It is required to have an assembly structure that can ensure robustness and that can ensure the inter-layer dielectric strength defined by the standard between the main circuit terminals of each phase.
[0006]
In this regard, in the above-described conventional main body case 1, the above-described components are assembled in advance for each of the lower case 1a, the upper cover 1b, and the intermediate case 1c, and then each of the upper cover 1b and the intermediate case 1c is mounted on the lower case 1a. It is an assembly structure in which components are overlapped and screwed together, and each division case is not provided with positioning / holding means for setting a predetermined assembly position of the combination division case. For this reason, in the assembly process, the alignment work when the intermediate case 1c and the upper cover 1b are sequentially stacked on the lower case 1a is troublesome, and at the stage before screw fastening, it is stacked vertically during transfer between processes. There is also a possibility that the combined divided cases may move relative to each other. Also, if there is a gap between the end face of the phase interval wall and the mating part that overlaps it in the assembled state of the main body case due to dimensional errors, assembly errors, etc. of the split case, the required insulation creepage distance between the phases of the main circuit terminals will be There is also a problem that it cannot be secured.
[0007]
The present invention has been made in view of the above points, and the object of the present invention is to solve the above-mentioned problems, to improve the assemblability and robustness, and to ensure sufficient insulation between the phases of the main circuit terminals. An object of the present invention is to provide a circuit breaker having an improved assembly structure.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a main circuit terminal of each phase, a fixed, a movable contact, an arc extinguishing unit, a contact opening / closing mechanism, and an overcurrent trip device are provided on a main body case which is a resin molded product. A circuit breaker constructed by incorporating the main body case into a lower case incorporating contacts and arc extinguishing parts for each phase, and a power supply side and load side main circuit for each phase arranged separately at the front and rear ends of the case Comprising an assembly of an intermediate case mounted with a terminal lead-out part, a contact opening / closing mechanism part, an overcurrent tripping device and fitted on the lower case, and an upper cover covering the intermediate case; and between the lower case and the intermediate case, and the intermediate case and to form the interphase wall between the upper cover those to partition the phases, as well as integrally forming the phase spacing wall to said top cover, The lower part The phase interval wall formed integrally with the scan, together with the tip of the interphase wall of the upper cover on the upper surface of the intermediate case is fitted, and forms a pocket-like receptacle which end faces of the longitudinal side of the main body case is closed A concave groove portion in which the phase spacing wall of the lower case fits is formed on the lower surface side of the intermediate case (Claim 1), and the embodiment can be configured as follows.
[0009]
(1) An outer wall is bulged on the side wall of the intermediate case, and the outer wall is sandwiched between the side wall of the upper cover and the side wall of the lower case.
(2) The upper case and the lower case surround the intermediate case, and the side walls of the upper cover and the lower case are faced up and down to assemble the main body case (Claim 3 ).
(3) interphase walls formed in the upper cover, and a socket formed in the intermediate casing is formed by overhanging the front and rear from the end face of the body case (claim 4).
[0010]
According to the above configuration , in the assembly process of the circuit breaker, when the intermediate case is fitted over the lower case, the upper edge of the phase spacing wall of the lower case is formed in the concave groove formed on the bottom side of the intermediate case. It is fitted and held in the assembly position. Subsequently, when the upper cover is attached onto the intermediate case from above, the leading end of the phase interval wall of the upper cover is fitted into the receiving port formed on the upper surface side of the intermediate case and is positioned and held. This makes it easy to align the divided cases in the assembly process, and when the divided cases are overlapped, the phase spacing walls of the lower case and the upper cover are fitted into the grooves of the intermediate case to the assembled position. Since they are constrained to each other, the rigidity of the main body case is increased and the body case becomes more robust, and there is no possibility of shifting from the assembly position during transfer between assembly processes. In addition, since the end of the phase spacing wall overlaps with the receptacle and concave groove of the intermediate case, which is the counterpart component, it absorbs some dimensional errors and maintains the necessary insulation creepage distance between the main circuit terminals of each phase. High insulation can be secured.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below based on the examples shown in FIGS. In addition, in the figure of each Example, the same code | symbol is attached | subjected to the member corresponding to FIG. 5, and the detailed description is abbreviate | omitted.
[0012]
In FIG. 1, 1a is a lower case, 1b is an upper cover, and 1c is an intermediate case. Although not shown, the lower case 1a has an assembly of a movable contact 6 and an arc extinguishing plate 9 as described in FIG. (See FIG. 5) is incorporated, and the power supply side and load side main circuit lead-out terminals 2 and 3, the contact opening / closing mechanism 11, and the overcurrent tripping device 13 are mounted on the intermediate case 1c.
[0013]
Here, the lower case 1a is integrally formed with a rib-like phase interval wall 1a-1 standing up from the bottom of the case so as to partition each phase. In addition, 1a-2 is a vent hole which leads to the arc extinguishing chamber opened at the front and rear end faces of the case. In addition, a phase interval wall 1b-1 is formed in the front and rear regions inside the upper cover 1b, and the front and rear ends of the phase interval wall 1b-1 protrude from the end face of the cover. A window hole 1b-2 is opened on the upper surface of the cover so that the upper end of the contact opening / closing mechanism 11 protrudes.
[0014]
On the other hand, on the upper surface side of the intermediate case 1c, a pocket-shaped receiving port 1c-1 is formed into which the tip of the phase interval wall 1b-1 of the upper surface cover 1b is fitted in the assembled state of the main body case 1 shown in FIG. As shown in the drawing, the receiving end 1c is closed at the front end, and projects from the end surface of the case in accordance with the protruding dimension of the phase interval wall 1b-1 of the upper cover 1b. Further, a concave groove 1c-3 into which the upper edge of the phase spacing wall 1a-1 of the lower case 1a is fitted is formed on the lower surface side along the longitudinal direction. Furthermore, an outer wall portion 1c-4 corresponding to the shape of the notch portion 1a-3 of the lower case 1a and the notch portion 1b-3 of the upper cover 1b is bulged and formed on the rear side (load side) side wall. In the assembled state shown in Fig. 3, the outer wall portion 1c-4 of the intermediate cover 1c is entangled with the side walls of the lower case 1a and the upper cover 1b to form a flat side wall surface of the main body case 1. In FIG. 1, 1c-5 is a terminal block of the main circuit terminal, and the terminal conductor and terminal screw shown in FIG.
[0015]
In the circuit breaker assembling process, first, the intermediate case 1c is fitted to the lower case 1b from above, and is stacked at a fixed position. As a result, the upper edge of the phase spacing wall 1a-1 of the lower case 1a is fitted into the concave groove 1c-3 of the intermediate case 1c, and the two are coupled. Next, the upper cover 1b is attached from above, and the phase interval wall 1b-1 is fitted into the receiving port 1c-1 of the intermediate case 1c to be restrained at a predetermined assembly position. As a result, the assembled state shown in FIG. 3 is obtained. In addition, between the upper cover 1b and the lower case 1a is fixed with a fastening screw (not shown) from the assembled state of FIG.
[0016]
As can be seen from the above description, according to the assembly structure of the illustrated embodiment, the three divided cases of the lower case 1a, the upper cover 1b, and the intermediate case 1c interlace with each other to hold a predetermined assembly position. The positioning and assembling between the divided cases are improved, and the rigidity of the main body case in the assembled state is increased. Further, the phase interval walls 1a-1 and 1b-1 separating the phases are fitted in the receiving port 1c-1 and the recessed groove 1c-3 of the intermediate case 1b in the assembled state, and the wall surfaces thereof are left and right. Therefore, the effective insulation creepage distance between adjacent main circuit terminals is increased, and high interphase dielectric strength can be ensured. In this case, the insulation creepage distance between the phases is further increased by projecting the phase interval wall 1b-1 and the end 1c-2 of the receiving port from the end surface of the main body case 1 back and forth as in the illustrated example. .
[0017]
FIG. 2 shows an application example. In this example, priority is given to the interphase insulation of the main circuit terminal lead-out portion, and the receptacle 1c-1 of the phase interval wall formed on the upper surface side of the intermediate case 1c is a terminal block 1c--. It is limited to the area surrounding 5. Although not shown, the length dimension of the phase interval wall of the upper cover 1b is also set in accordance with the length size of the receiving port 1c-1 in FIG.
[0018]
FIG. 4 is a diagram showing an assembled state of a further different application example. In this embodiment, the intermediate case is surrounded by the lower case 1a and the upper cover 1b and incorporated therein, and the side walls of the lower case 1a and the upper cover 1b along the straight abutting surface A as shown in the figure. The end faces are overlapped. That is, the outer wall 1c-4 bulging from the side wall of the intermediate case 1c described in FIG. 1, the notch 1a-3 of the lower case 1a, and the notch 1b-3 of the upper cover 1b are not formed. The structure is similar to that of FIG.
[0019]
【The invention's effect】
As described above, according to the configuration of the present invention, the main body case to be a resin molded product is divided into three parts, a lower case, an upper cover, and an intermediate case, and each part of the circuit breaker is incorporated. The phase spacing wall is integrally formed on the cover , the phase spacing wall is integrally formed on the lower case, the tip of the phase spacing wall of the upper cover is fitted on the upper surface side of the intermediate case , and In the assembly process of the circuit breaker, the lower case is formed by forming a pocket-shaped receiving port whose end face is closed, and forming a concave groove portion into which the phase spacing wall of the lower case fits on the lower surface side of the intermediate case. Phase spacing walls between the intermediate case and between the upper cover and the intermediate case are fitted into the recessed groove and the receiving port, respectively, and are restrained and held at the assembly position. Therefore, the positioning of each divided case in the assembly process can be easily performed, the rigidity of the main body case in the assembled state is increased, and the insulation creepage distance between the main circuit terminals of each phase is increased, thereby improving the insulation. Effects such as improvement can be obtained.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a circuit breaker body case showing a configuration of an embodiment of the present invention. FIG. 2 is a perspective view of a configuration of an intermediate case according to an application embodiment of the present invention. FIG. 4 is an external view showing the assembly state of the main body case according to still another application embodiment of the present invention. FIG. 5 is an assembly example of a conventional bridge type two-contact circuit breaker. Structure [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body case 1a Lower case 1a-1 Phase space | interval wall 1b Upper cover 1b-1 Phase space | interval wall 1c Intermediate | middle case 1c-1 Receptacle 1c-3 Groove | groove 2, 3 Main circuit terminal 6 Movable contact 9 Arc-extinguishing plate 11 Contact opening / closing mechanism 13 Overcurrent trip device

Claims (4)

A circuit breaker configured by incorporating a main circuit terminal of each phase, a fixed, movable contact, an arc extinguishing unit, a contact opening / closing mechanism, and an overcurrent trip device in a main body case to be a resin molded product, There is a lower case incorporating contacts and arc extinguishing parts for each phase, and the power supply side, load side main circuit terminal lead-out part, contact switching mechanism, An intermediate case mounted on the lower case and mounted on the lower case, and an upper cover covering the intermediate case, and between the lower case and the intermediate case, and the intermediate case In what made the phase interval wall between the upper cover and partition each phase,
The phase interval wall is integrally formed with the upper cover , the phase interval wall is integrally formed with the lower case, the top end of the phase interval wall of the upper cover is fitted on the upper surface side of the intermediate case , and the longitudinal direction of the main body case to form a pocket-like receptacle in which an end face of the side is closed, the circuit breaker, characterized in that the formation of the said Mari fit groove portion fitting the phase spacing walls of the lower case to the lower surface of the intermediate case. 2. The circuit breaker according to claim 1, wherein an outer wall portion is formed to bulge on the side wall of the intermediate case, and the outer wall portion is sandwiched between the side wall of the upper cover and the side wall of the lower case. 2. The circuit breaker according to claim 1, wherein the upper case and the lower case surround the intermediate case, and the body case is assembled by vertically butting the end faces of the upper cover side wall and the lower case side wall. Circuit breaker. 2. The circuit breaker according to claim 1, wherein a phase interval wall and a receiving port formed between the upper cover and the intermediate case are formed so as to protrude forward and backward from an end surface of the main body case.

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