JP2016195055A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an assembly structure of a circuit breaker improved so that a through current transformer, fitted to a main circuit conductor to be laid in the body case by simple snap-fit coupling, can be fixed and supported while being positioned at a predetermined assembly position.SOLUTION: In a circuit breaker including a main circuit conductor 7 laid in the body case, and a through current transformer 9 into which the main circuit conductor 7 is fitted as a primary conductor, where a contact is opened when the overcurrent state of an electrical path is detected based on the output signal from the through current transformer 9, a resin holder 12 for holding the main circuit conductor 7 is provided in the body case, a tab-shaped engagement protrusion 9d is provided on the enclosure resin case 9c of the through current transformer 9, the through current transformer 9 is fitted in the main circuit conductor 7, and while fitting the main circuit conductor 7 in the conductor holding groove 12b of the holder 12, the engagement protrusion 9d is hooked to the engagement hole 12d of the holder 12 thus fixing the through current transformer 9 to a predetermined assembly position.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to an electronic circuit breaker, and more specifically, a main circuit conductor laid between main circuit terminals via a contact inside a main body case, and a through-type current transformer fitted and arranged in the main circuit conductor. Related to the assembly support structure.

  As is well known, circuit breakers for wiring include thermal-electromagnetic, fully electromagnetic, and electronic types depending on the trip system. In this electronic circuit breaker, a current transformer that measures the current flowing in the circuit is built in the main body case of the circuit breaker, and then the secondary output of this current transformer is sent to the electronic control circuit and the current flowing in the circuit When an overcurrent flows through the electric circuit, the electronic control circuit outputs a trip command to the contact opening / closing mechanism to open the electric circuit (see, for example, Patent Document 1).

  Next, an example of a simplified assembly structure of the electronic circuit breaker is shown in FIG.

  In FIG. 4, 1 is a main body case made of a mold resin made up of a box-shaped case 1 a and an upper cover 1 b, 2 is a power supply side terminal, 3 is a load side terminal, and 4 is integrally connected to the power supply side terminal 2. A fixed contact arranged on the bottom side, 5 is a movable contact having a movable contact facing the fixed contact 4a of the fixed contact 4, 6 is an arc extinguishing grid of an arc extinguishing device, 7 is a flexible connecting conductor 8 at one end. The main circuit conductor 9 connected and laid between the movable contact 5 and the load side terminal 3 is inserted into the intermediate portion of the main circuit conductor 7 by using the main circuit conductor 7 as a primary conductor. This is a through-type current transformer that measures the current flow. Further, 10 schematically shown in the drawing is a contact opening / closing mechanism disposed on the inner upper side of the main body case 1, and 11 is an electronic control circuit. The operation and function of the circuit breaker configured as described above is also described in detail in the above-mentioned Patent Document 1.

  4 represents one pole. For example, in a circuit breaker applied to a three-phase circuit, U, V. Between the main circuit terminals corresponding to the W phases, the stationary contact 4, the movable contact 5, the main circuit conductor 7, and the through-type current transformer 9 are accommodated and arranged in the body case 1 side by side.

  In addition, this type of circuit breaker is used in the circuit breaker illustrated in FIG. 4 in order to share the assembly parts in accordance with the product lineup with the earth leakage circuit breaker and to reduce the size and size. The intermediate portion of the circuit conductor 7 is bent into a Z shape as shown in the figure, and the through-type current transformer 9 is inserted and disposed in the bending position in the bent portion.

  Next, the detailed assembly structure of the main circuit conductor 7 and the feedthrough current transformer 9 is shown in FIGS. That is, the main circuit conductor 7 is a flat copper bar conductor, and the bar conductor is inserted into the divided conductors 7a, 7b, 7c in advance in order to insert the through-type current transformer 9 in the Z-shaped bent portion formed in the middle. Z-shaped bending is performed by inserting a through-type current transformer 9 into an intermediate divided conductor 7b that is divided and extending in the vertical direction, and joining the divided conductors 7a, 7b, and 7c by brazing or the like. Part (see FIG. 5).

  The through-type current transformer 9 has a structure in which a secondary winding 9b (toroidal coil) is wound around an annular core 9a and then accommodated in an annular outer resin case 9c (see FIG. 6).

  In addition, in place of the through-type current transformer 9, when an earth leakage circuit breaker is configured by inserting and arranging a zero-phase current transformer in the main circuit conductor 7 laid in the body case, For the main circuit conductor 7 of each pole (U, V, W phase in three phases) laid on the center, the bent part of the main circuit conductor (U, W phase) arranged on the left and right sides is brought close to the center pole (V phase) Then, the zero-phase current transformer is inserted and arranged in a horizontal posture so as to surround the main circuit conductor 7 of each pole.

Japanese Unexamined Patent Publication No. 7-212217

  By the way, in the assembly structure of the circuit breaker for wiring in which the through-type current transformer 9 is inserted and arranged in the main circuit conductor 7 as shown in FIG. 4, the through-type current transformer 9 is secured in order to ensure the assemblability and reliability of the product. Must be fixed at the predetermined assembly position and fixedly supported on the main circuit conductor 7 or the main body case 1 or the like. That is, since the output end of the secondary winding (thin wire) of the feedthrough current transformer 9 is connected to the printed board of the electronic control circuit 11, if the position shifts from a predetermined position, the current transformer 9 There is a possibility that unnecessary force is applied to the secondary winding and the connection lead is broken.

  In this respect, conventionally, the through-type current transformer 9 is molded integrally with the divided conductor 7b (see FIG. 5) of the main circuit conductor 7. Alternatively, as disclosed in FIG. 1 of Patent Document 1, the main body of the current transformer (10) is integrally formed with a resin current transformer holder (22), and the main body case ( 14) is incorporated at a predetermined position.

  However, in order to integrate the through-type current transformer 9 with the main circuit conductor 7 or the current transformer holder as described above, a resin molding process is required in the product assembly line. In addition, the manufacturing cost increases.

  The present invention has been made in view of the above points, and its object is to eliminate equipment and processes by the conventional resin molding method, and to apply a simple insertion and snap-fit coupling to the main circuit conductor and the main circuit conductor. It is an object of the present invention to provide an improved circuit breaker assembly structure that can be fixedly supported by positioning each component of a through-type current transformer inserted into a predetermined assembly position.

In order to achieve the above object, according to the present invention, a main circuit conductor laid between a power supply side terminal and a load side terminal of each pole through a contact inside the main body case, and the main circuit conductor as a primary Equipped with a through-type current transformer that is inserted into the main circuit conductor connected to the load side terminal as a conductor, and the contact is opened when an overcurrent state of the circuit is detected based on the output signal of the through-type current transformer. In the circuit breaker that opens the circuit by pole operation,
A resin holder for holding the main circuit conductor of each pole is housed inside the main body case, and a tab-shaped engaging protrusion is provided on the outer resin case of the through-type current transformer so that the through-type The current transformer is inserted into the main circuit conductor and the main circuit conductor is held by the holder, and the engaging projection is hooked on the holder to fix the through-type current transformer at a predetermined assembly position. 1) It can be specifically configured in the following manner.
(1) In the above configuration, a pair of left and right tab-like engagement protrusions are provided in the surrounding resin case of the through-type current transformer, and an engagement hole is formed in the wall surface of the holder so as to face the engagement protrusions. Then, at the time of assembly, the engaging protrusion is inserted into the engaging hole of the holder, and the through-type current transformer is latched and fixed at a predetermined assembly position (Claim 2).
(3) In the above configuration, the main circuit conductor is a bar conductor whose middle portion is bent in a Z-shape, and a through-type current transformer is inserted and disposed in a horizontal posture at a bent portion of the bar conductor, while the holder Is a resin member having an L-shaped cross section, and a conductor holding groove is formed in the bottom wall portion to receive the main circuit conductor leading to the load side terminal, and a through-type current transformer is formed in the wall portion standing up from the rear end of the bottom wall portion. An engagement hole for engaging the engagement protrusion of the container is formed (claim 3).

  According to the above assembly structure, when assembling the main circuit conductor and the through-type current transformer fitted into the main circuit conductor in the body case in the assembly process of the circuit breaker, The main circuit conductor of each pole is fitted and held in the resin holder, and the tab-like engagement protrusion provided on the outer resin case of the through-type current transformer is inserted into the engagement hole formed in the wall surface of the holder. By stopping (snap-fit connection), the main circuit conductor and the through-type current transformer can be fixedly supported at a predetermined assembly position by a simple assembly operation, eliminating the resin molding process required for the conventional assembly structure. As a result, the assembly of the product can be improved and the manufacturing cost can be reduced.

It is a figure showing the assembly structure of the main circuit conductor of the circuit breaker for wiring by the Example of this invention, a penetration type current transformer, and a holder, (a) is a sectional side view, (b) is P in (a). It is a perspective view of a part. It is a perspective view of the temporary assembly state which inserted the penetration type current transformer in the main circuit conductor in FIG. It is a disassembled perspective view explaining the assembly process which positions and supports the temporary assembly of FIG. 2 to a holder. It is sectional drawing by the side view of the whole conventional circuit breaker for wiring. It is a perspective view showing the temporary assembly state of the main circuit conductor and penetration type current transformer in FIG. FIG. 6 is a perspective sectional view of the through-type current transformer in FIG. 5.

  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. 4, and the description is abbreviate | omitted.

  In FIG. 1, a main circuit conductor 7 that is a flat bar conductor bent in a Z shape in the middle of the wiring path, and a through-type current transformer 9 that is inserted into the bent portion of the main circuit conductor 7 in a lateral posture are as follows: Each component is positioned and held at a predetermined assembly position using the resin holder 12 having the following structure as an assembly base, and the detailed assembly structure and assembly procedure will be described below.

  First, the main circuit conductor 7 is formed with a Z-shaped bent portion by combining the divided conductors 7a, 7b, and 7c as in FIG. Further, with respect to the through-type current transformer 9 that is fitted and arranged in the divided conductor 7b extending in the vertical direction corresponding to the bent portion of the main circuit conductor 7, the peripheral surface of the surrounding resin case 9c (see FIG. 6) A pair of left and right tab-like engagement protrusions 9d are integrally formed so as to protrude from the back toward the rear, and a square hole 9d-1 is opened on the plate surface of the engagement protrusion 9d.

  On the other hand, a holder 12 for positioning and holding the main circuit conductor 7 and the through-type current transformer 9 at a predetermined assembly position is a resin member having an L-shaped cross section as shown in the figure, and a load side terminal is provided on the bottom wall portion 12a. 3 (see FIG. 4), a conductor holding groove 12b into which the divided conductor 7c of the main circuit conductor 7 is inserted is formed, and a wall-type current transformer is formed on the wall surface of the wall portion 12c rising from the rear end of the bottom wall portion 12a. An engagement hole 12d into which the engagement protrusion 9d is inserted is formed, and a wedge-shaped taper-shaped hook that snap-fits to the square hole 9d-1 of the engagement protrusion 9d is formed on the inner surface of the engagement hole 12d. A pawl 12d-1 is formed. In addition, a conductor through hole 12e connected to the conductor holding groove 12b is formed in the base portion of the wall portion 12c.

  Next, the assembly procedure of the main circuit conductor 7 and the through-type current transformer 9 will be described. First, with respect to the main circuit conductor 7 having a three-divided structure of divided conductors 7a, 7b and 7c as shown in FIG. Then, the divided conductors 7a to 7c are joined to each other and temporarily assembled, and in the subsequent process, the temporary assembly is assembled to the holder 12 as shown in FIG. At this time, the through-type current transformer 9 in which the divided conductor 7c of the main circuit conductor 7 is inserted into the conductor holding groove 12b formed in the bottom wall portion 12a of the holder 12 from the front and is inserted into the main circuit conductor 7 in the same process. Then, a pair of left and right tab-like engagement protrusions 9d protruding rearward from the surrounding resin case are pushed into the engagement holes 12d formed in the wall 12c of the holder 12, and the corners of the tab-like engagement protrusions 9d are The through-type current transformer 9 is snap-fit coupled to the holder 12 by engaging the hole 9d-1 with a latching claw 12d-1 formed on the inner wall surface of the engagement hole 12d. After assembling the main circuit conductor 7 and the through-type current transformer 9 corresponding to each of the three-phase poles in the holder 12 in the same assembly procedure as described above, this assembly is assembled to the main body case 1 shown in FIG. The holder 12 is assembled inside and fixed inside the main body case 1.

  The holder 12 shown in FIG. 3 is made for three poles. The bottom wall portion 12a and the wall portion 12c of the holder 12 have conductor holding grooves 12b corresponding to the U, V, and W phase poles. Although the engagement holes 12d of the through-type current transformer 9 are formed side by side on the left and right, the holder 12 may have a divided structure corresponding to each pole individually.

  As is apparent from the above description, according to the assembly structure of the present invention, the resin holder 12 incorporated in the main body case is used as an assembly member, and the main circuit conductor 7 of each pole and the main circuit conductor 7 are connected thereto. By inserting and inserting the tab-like engaging protrusions of the inserted through-type current transformer 9, the main circuit conductor 7 and the through-type current transformer 9 are fixedly supported at a predetermined assembly position, and the through-type current transformer 9 It is possible to reliably prevent coil disconnection accidents caused by unnecessary displacement.

  As a result, the through-type current transformer 9 loosely fitted to the main circuit conductor 7 does not require an assembling process by a resin mold which is troublesome as in the prior art. The product can be fixedly supported to improve the assembling property, shorten the assembling time, and improve the productivity of the product.

DESCRIPTION OF SYMBOLS 1 Main body case 2 Power supply side terminal 3 Load side terminal 4 Fixed contact 5 Movable contact 7 Main circuit conductor 7a-7c Split conductor 9 Through-type current transformer 9c Enclosed resin case 9d Tab-shaped engagement protrusion 12 Holder 12a Bottom Wall portion 12b Conductor holding groove 12c Wall portion 12d Engagement hole

Claims (3)

A main circuit conductor laid between the power-side terminal and the load-side terminal of each pole via a contact inside the main body case, and the main circuit conductor serving as a primary conductor to be inserted into the main circuit conductor connected to the load-side terminal. In the circuit breaker for wiring that opens the circuit by opening the contact when the overcurrent state of the circuit is detected based on the output signal of the through-type current transformer,
A resin holder for holding the main circuit conductor of each pole is housed inside the main body case, and a tab-shaped engaging protrusion is provided on the outer resin case of the through-type current transformer so that the through-type The through-type current transformer is fixed at a predetermined assembly position by fitting the current projection into the main circuit conductor and holding the main circuit conductor in the holder, and the engagement protrusion is hooked on the holder. Wiring circuit breaker.   2. The circuit breaker according to claim 1, wherein a pair of left and right tab-like engagement protrusions are provided on the outer resin case of the through-type current transformer, and the wall surface of the holder is engaged with the engagement protrusions. A breaker for wiring, wherein a hole is formed, and the engaging protrusion is inserted into an engaging hole of a holder at the time of assembling, and the through-type current transformer is latched and fixed at a predetermined assembling position.   The circuit breaker according to claim 1 or 2, wherein the main circuit conductor is a bar conductor whose middle portion is bent in a Z-shape, and a through-type current transformer is fitted in a horizontal posture at a bent portion of the bar conductor. On the other hand, the holder is a resin member having an L-shaped cross section, and the bottom wall portion is formed with a conductor holding groove into which the main circuit conductor leading to the load side terminal is fitted, and the wall stands up from the rear end of the bottom wall portion The circuit breaker for wiring is characterized in that an engagement hole for engaging an engagement protrusion of the through-type current transformer is formed in the part.

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