JPH097490A - Short-circuit current detecting device of circuit breaker - Google Patents

Abstract

PURPOSE: To provide a short-circuit current detecting device of a circuit breaker by which machining work of a terminal board is facilitated and an inside diemsion of an apparatus body can be secured large and a height of the apparatus body can be reduced. CONSTITUTION: A load side terminal board 17 is formed in a plate shape, and is placed and arranged on a terminal stand 13b exposed to an outside surface of an apparatus body 10. A terminal separating plate 18 of a magnetic substance is arranged above the load side terminal board 17 in a part between a connecting part of an external circuir and a connecting part of an internal circuit in the load side terminal board 17. A movable plate 42 is inserted into a holding recessed place 11f, and can freely move in the vertical direction, and is energized downward by a return spring 44. When a short-circuit current passes to a main cable way, the terminal separating plate 18 and the movable plate 42 are magnitized by a magnetic field formed around the load side terminal board 17, and the movable plate 42 moves upward, and actuates a trip device by an upward movement of a plunger 43.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short-circuit current detecting device for a circuit breaker which opens a contact device by operating a trip device when a short-circuit current passes.

[0002]

2. Description of the Related Art Generally, in a circuit breaker such as a wiring breaker or an earth leakage breaker, when a short-circuit current flows in a main circuit in which a contact device is inserted, the short-circuit current is detected to activate a trip device. The contact device is thereby opened. That is, a short-circuit current detection device is provided to detect a short-circuit current flowing in the main circuit and operate the trip device. As a short-circuit current detection device of this type, a diagram described in Japanese Patent Laid-Open No. 5-342966 is disclosed. There is a configuration shown in 22.

The short-circuit current detection device shown in the figure has a structure in which a fixed magnetic body 2 and a movable magnetic body 3 are arranged on both sides in the thickness direction of a terminal plate 1 passing through a main electric path, and the movable magnetic body 3 is housed in a case 4. Have Further, a plate portion 5 that rises upward is formed on the terminal plate 1 so as to separate a connection portion with an external circuit from a connection portion with an internal circuit, and is a heater plate that is connected to the terminal plate 1 and heats the bimetal plate 6. Case 4 between 7 and plate 5
Is held. That is, when a short-circuit current flows in the main circuit including the terminal plate 1, the plate portion 5 and the heater plate 7
The magnetic field formed around the electric circuit conductor 8 that connects with the fixed magnetic body 2 and the movable magnetic body 3 is attracted to the fixed magnetic body 2 to move the movable magnetic body 3. The contact device is opened by transmitting it to the trip device.

[0004]

However, in the structure described in the above publication, the plate portion 5 is provided on the terminal plate 1 and the electric circuit conductor 8 is formed so as to be continuous with the heater plate 7. As a result, many bending portions are formed on the terminal board 1, and there is a problem that the work of processing the terminal board 1 is troublesome. Further, since the case 4 is arranged between the plate portion 5 of the terminal plate 1 and the heater plate 7, the internal size of the body is reduced by the thickness of the case 4, and the upper end of the plate portion 5 and the heater plate 7 are reduced. Since the ambient magnetic field of the electric circuit conductor 8 connecting with 7 is used, the fixed magnetic body 2 and the movable magnetic body 3 are arranged relatively above, and it is difficult to reduce the height of the body.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to use a terminal plate having a simple shape with no bent portion, thereby facilitating the working operation and making the terminal plate easy. It is an object of the present invention to provide a short-circuit current detection device for a circuit breaker, which does not require a plate portion, can increase the internal size of the body and can reduce the height of the body.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, a circuit breaker for operating the trip device to open the contact device when a short-circuit current passes through a main circuit passing through the contact device. In a short-circuit current detection device for a container, a flat terminal plate mounted on a terminal block exposed on the outer surface of the container and forming a part of the main electric circuit, and a connection part between an external circuit and an internal circuit in the terminal plate. Between the terminal plate and the terminal plate, which is made of a magnetic material and is arranged at a fixed position on one surface side in the thickness direction of the terminal plate so as to be substantially orthogonal to the terminal plate, and faces a part of the terminal plate with the terminal plate interposed therebetween. A movable plate made of a magnetic material that is arranged so as to be movable in the thickness direction of the terminal plate so that the distance to the terminal isolation plate is variable, and is formed around the terminal plate when a short-circuit current passes through the main circuit. When the movable plate is attracted to the terminal separator by the magnetic field Trip device by movement characterized by actuation.

According to a second aspect of the present invention, in the first aspect of the present invention, a holding recess into which the movable plate is inserted so as to be movable back and forth is formed on the bottom surface of the terminal block, and the movable plate is biased in a direction away from the terminal plate. A return spring is arranged between the terminal plate and the movable plate. According to a third aspect of the present invention, in the first or second aspect of the present invention, a connection electric wire that connects an electric circuit housed inside the body and an electric circuit outside the body is inserted into the terminal separator. The wire insertion opening is formed.

[0008]

According to the structure of the invention of claim 1, the terminal isolation plate made of a magnetic material is arranged on one surface side in the thickness direction of the terminal board, and the movable plate made of a magnetic material is arranged on the other surface side to allow passage of a short-circuit current. The magnetic field formed around the terminal board is sometimes passed through the terminal board and the movable board to attract the movable board to the terminal board, and the terminal board connects the terminal board to the external circuit. Since the space between the connection part and the connection part with the internal circuit is isolated, the internal space of the body can be widened as compared with the conventional configuration in which the plate part is raised. In addition, since the rising portion is not formed by using the flat terminal plate, it is possible to reduce the height of the body. Moreover, since it is not necessary to provide a bent portion on the terminal plate, the shape of the terminal plate becomes simpler than before, and the work of processing the terminal plate becomes easier.

According to the second aspect of the present invention, since the holding recess is formed in the bottom surface of the terminal block to mount the movable plate,
A case for restricting the moving direction of the movable plate is not necessary, and as a result, it is possible to reduce costs by reducing the number of parts. In addition, since the case is unnecessary, not only the number of parts is reduced, but also when the current flowing in the main circuit contains vibration components of audible frequency, the conventional configuration causes rattling noise due to rattling of the case. However, in the invention of claim 2, since there is no case, a beat noise does not occur.

According to the structure of the third aspect of the present invention, since the electric wire insertion opening is formed in the terminal separator, the electric circuit housed inside the body and the electric circuit outside the body can be connected. Since the electric wire insertion opening through which the connection electric wire for connecting the cable is inserted is formed, the external electric wire can be introduced through the electric wire insertion opening without additional hole processing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 5 and 6, a body 10 comprises a body 11 and a cover 12 each made of synthetic resin, and each end of the body 11 in the longitudinal direction is connected to a power source and a load. Terminal block 13 with screwed terminals to be connected
a and 13b are formed. In this embodiment, an earth leakage breaker used in single-phase three-wire or three-phase three-wire is shown, and each terminal block 1
Terminals for three poles are provided on 3a and 13b. The terminals of the respective poles are insulated from each other by partition walls 11a that partition the two side walls into three sections at both ends in the longitudinal direction of the body 11.

One end of the power source side terminal plate 14 is exposed to the terminal block 13a, and a leg portion of a terminal screw 15a made of a hexagon socket head bolt is inserted into the exposed portion of the power source side terminal plate 14 to allow the leg of the terminal screw 15a to pass through. A terminal nut 15b (see FIG. 1) is screwed into the portion. As shown in FIG. 7, a positioning piece 14a bent downward is formed at the other end of the power source side terminal plate 14, and the other end of the power source side terminal plate 14 is cut and raised to cut off the power source side terminal plate 14. A terminal support piece 14b located below the upper surface of 14 extends from the positioning piece 14a. Also,
The opening 14c is formed in the other end of the power supply side terminal plate 14 by cutting and raising the power supply side terminal plate 14, and the terminal support piece 1 exposed through the opening 14c.
A fixed contact 21 is fixed to the upper surface of 4b. Body 11
A support plate 16 formed in a substantially U-shape that opens upward is disposed on the bottom surface of the terminal support plate 14b. The terminal support plate 14b is mounted on the support plate 16 between both leg pieces of the support plate 16 and is attached to the body 11. It is stored. A positioning protrusion 11b (see FIG. 18) protruding from the bottom surface of the body 11 is inserted into the support piece 16, and the positioning piece 14a provided on the power source side terminal plate 14 is a positioning recess 11c formed in the bottom portion of the body 11. (See FIG. 18). Further, the power supply side terminal plate 14 is fixed to the body 11 by screwing a fixing screw 19 (see FIG. 1) inserted from the lower surface side of the body 11, and the support plate 16 is connected to the body 11 and the power supply side. It is fixed to the body 11 so as to be sandwiched between it and the terminal plate 14.

On the other hand, the load side terminal plate 17 is mounted on the terminal block 13b.
One end of the terminal is exposed, and like the power-side terminal board 14, the load-side terminal board 17 has a terminal screw 15a made of a hexagon socket head bolt and a terminal nut 15b screwed to the leg of the terminal screw 15a at the one end. It is provided. Further, the load side terminal plate 17 is fixed to the body 11 by screwing a fixing screw 19 inserted from the lower surface side of the body 11.

Power source side terminal plate 14 and load side terminal plate 17
As shown in FIG. 1, the terminal blocks 13a and 13b on which is mounted are formed with holding grooves 11d that are opened upward and outward of the body 10 so as to receive the terminal nuts 15b. A lid 15c made of sheet metal is detachably attached near the opening on the outer side of the body 10. That is, the holding groove 11d is formed in a shape that prevents the terminal nut 15b from rotating, and when the lid 15c is mounted, the body 1
The terminal nut 15b is prevented from dropping from 0.

One end of a substantially U-shaped heater plate 22 in one plane is connected to the other end of the load side terminal plate 17. Here, the load side terminal plate 17 and the heater plate 22 are arranged so as to be substantially orthogonal to each other. Further, one end of an indirectly heated bimetal plate 41 that is heated by the heat generated by the heater plate 22 is fixed to the other end of the heater plate 22, and the electric conductors 23a, One ends of 23b and 23c (see FIG. 8) are connected. The intermediate portions of the electric circuit conductors 23a, 23b, 23c are inserted into the leakage current detecting device 30, and the other end is connected to one end of the movable contact 25 via the braided wire 24. The movable contact 26 is provided at the other end of the movable contact 25 together with the fixed contact 21 described above, which constitutes a contact device. That is, between the power source side terminal plate 14 and the load side terminal plate 17, a contact device including a fixed contact 21 and a movable contact 26, a movable contact 25, a braided wire 24, and electric circuit conductors 23 a, 23.
A main electric path is formed which passes through b and 23c and the heater plate 22.

By the way, the heater plate 22 and the load side terminal plate 1
7, a terminal separating plate 18 made of a magnetic material and having an exhaust hole is formed between the side wall of the body 11 and the partition wall 11a, and the partition wall 11a. They are held between each other (mounting grooves 11e are formed on the side walls of the body 11 and the facing surfaces of the partition walls 11a, and both side portions of the terminal separating plate 18 are inserted into the mounting grooves 11e). Immediately below the terminal separating plate 18 with the load side terminal plate 17 interposed therebetween, a movable plate 42 formed of a magnetic material in a substantially U-shape that is open upward is disposed. As shown in FIGS. 2 and 3, the movable plate 42 is inserted into the holding recess 11f opening on the upper surface of the terminal block 13b at a portion corresponding to the mounting groove 11e, and is vertically movable in the holding recess 11f. Has become. FIG.
As shown in FIG. 5, a plunger 43 extended upward is caulked and fixed to the movable plate 42, and the movable plate 42 is a spring force of a return spring 44 formed of a coil spring sandwiched between the movable plate 42 and the load side terminal plate 17. Is urged downward by. A notch is formed in the side portion of the load side terminal plate 17 at a portion where the tip surfaces of both leg pieces of the movable plate 42 and the lower end surface of the terminal separating plate 18 face each other. That is, the tip surfaces of both leg pieces of the movable plate 42 and the lower end surface of the terminal separating plate 18 directly face each other.

Therefore, when a current of several tens of times or more of the rated current, such as a short-circuit current, flows in the main circuit, the terminal separating plate 18 is magnetized by the magnetic field formed around the heater plate 22, and the movable plate is moved. 42 is attracted to the terminal separator plate 18 against the spring force of the return spring 44. That is, when the short circuit current flows in the main circuit, the movable plate 42 and the plunger 43 move upward. Further, when an overcurrent of several times the rated current flows in the main circuit, the bimetal plate 41 is heated by the heat generated by the heater plate 22, and the bimetal plate 41 is heated.
The upper end portion of is curved in a direction away from the heater plate 22. A push screw 45 is screwed onto the upper end portion of the bimetal plate 41 so that the screwing amount of the push screw 45 can be adjusted.

A trip device 50 is provided at the center of the body 11.
Is stored. A general trip device 50 is used, but a brief description will be given. In the trip device 50, as shown in FIG. 18, the latch link 52, the latch plate 53,
The cradle 54 and the handle 55 are attached to the shafts 52a and 5 respectively.
It is pivotally attached to the metal frame 51 at 3a, 54a and 55a. In addition, the movable contactor 2 having one pole at the center of the three poles
5 and cradle 54 are links 56a and 56b, respectively.
Is pivoted at one end and the other ends of both links 56a and 56b are pivotally attached to each other. That is, the cradle 54 and the movable contact 25 are connected to each other via both the links 56a and 56b. A latch return spring 57 composed of a torsion coil spring is attached to the shaft 51a fixed to the frame 51,
Each one end of the latch return spring 57 has a latch link 5
2 and the latch plate 53. Here, the latch return spring 57 urges the latch plate 53 clockwise around the shaft 53a in FIG. Further, a handle return spring 58, which is a tension spring, is attached between the handle 55 and the shaft pin 56 that pivotally mounts the links 56a and 56b.

The movable contact 25 is held so as to be swingable in the plane of FIG. 18 with respect to the interlocking body 59 made of synthetic resin, and a contact pressure formed by a coil spring is provided between the movable contactor 25 and the interlocking body 59. The spring 46 is retained. The contact pressure spring 46 urges the movable contact 25 in a direction to apply contact pressure when the movable contact 26 is closed with respect to the fixed contact 21, and is movable when the movable contact 26 is opened with respect to the fixed contact 21. The movable contact 25 is biased in a direction in which the contact 26 is separated from the fixed contact 21. The interlocking body 59 has a shaft portion 59a rotatably supported by the body 11, and holds all the movable contacts 25 of three poles. Therefore, in conjunction with the opening / closing operation of the one-pole movable contact 25, the other two-pole movable contact 25 similarly opens / closes.

On the other hand, an interlocking bar 47 is supported on the body 11 so as to extend over three poles, and the interlocking bar 47 has the above-mentioned plungers 43 moved upward as shown in FIG. Sometimes the plunger 43 pushes the interlocking bar 47.
18 is provided with three kick pieces 47a that rotate counterclockwise in FIG. Also, bimetal plate 4
When 1 is bent, it is pushed by the push screw 45 screwed into the bimetal plate 41 to rotate the interlocking bar 47 counterclockwise in FIG. 18 around the bearing portion.
b is projected. Further, the interlocking bar 47 is provided with a set cylinder portion 47c into which a set piece 52b protruding from the latch link 52 is inserted.

The above-mentioned handle 55 projects from the upper surface of the body 10 so as to be able to rise and fall, and when it is tilted to the left end side as shown in FIG. 18, the movable contact 26 is brought into contact with the fixed contact 21 to close it. In this state, the set piece 52b of the latch link 52 is inserted into the set tube portion 47c of the interlocking bar 47. At this time, since the latch plate 53 is locked by the cradle 54, the force for rotating the latch plate 53 clockwise about the shaft 53a by the spring force of the latch return spring 57 becomes small. In addition, the latch link 52 is the latch return spring 5
The spring force of 7 tries to rotate counterclockwise around the shaft 52a, but it stops at the position of FIG. 18 by contacting the upper edge of the latch plate 53. That is, in the state of FIG. 18, the latch plate 53 is kept in contact with the latch link 52. The cradle 54 is also locked to the latch plate 53 to prevent rotation around the shaft 54a. At this time, the spring force of the handle return spring 58 acts in a direction in which the links 56a and 56b are developed in a straight line, and the movable contact 25 is pushed downward. That is, the movable contact 26 is kept at a position where it contacts the fixed contact 21.

On the other hand, when the handle 55 is tilted to the right end side as shown in FIG. 19 with the cradle 54 engaged with the latch plate 53, the upper end of the handle return spring 58 causes the link 56b to be pivotally attached to the cradle 54. The links 56a and 56b are bent in a V shape and move the movable contact 25 upward because they move to the right. That is,
The movable contact 26 separates from the fixed contact 21 and opens.

By the way, the cradle 54 is attached to the latch plate 53.
Is engaged, the interlocking bar 47 causes the body 11 to move.
Assuming that it rotates counterclockwise around the pivotal support portion, the setting piece 52b of the latch link 52 is pressed by the inner surface of the setting tube portion 47c of the interlocking bar 47 and moves downward as shown in FIG. That is, the latch plate 53 is the latch link 5
2, the latch plate 53 is rotated clockwise because the force that tries to rotate the latch plate 53 clockwise around the shaft 53a is released, and the latch plate 53 rotates clockwise. At this time, cradle 5
4 and the latch plate 53 are disengaged, and the cradle 54
Can freely rotate, the spring force of the handle return spring 58 bends the links 56a and 56b,
The movable contact 25 is pulled up. That is, the movable contact 26 separates from the fixed contact 21 and opens. Such an operation is generally called a trip operation.

In order to return the latch plate 53 and the cradle 54 from the disengaged state to the engaged state as shown in FIG. 20, the handle 55 may be tilted to the right end side. At this time, the cradle 54 is provided with the pressing pin 5 provided on the handle 55.
When pressed by 5b, it rotates clockwise around the shaft 54a, and the latch link 52 is pressed by the handle 55 and rotates counterclockwise around the shaft 52a. That is, if the handle 55 is tilted to the right end side sufficiently, as shown in FIG.
The cradle 54 engages with the latch plate 53, and the movable contact 26 returns to the state in which the fixed contact 21 is opened.
To close the movable contact 26 with respect to the fixed contact 21,
After that, the handle 55 may be tilted to the left end side.

In the trip operation as described above, the plunger 43 moves upward due to the short circuit current and the interlocking bar 47 is moved.
The kick piece 47a is pushed up, or the overcurrent causes the bimetal plate 41 to bend and the push screw 45 to push the pushing piece 47a.
This is performed either when the user presses b, when the earth leakage current detection device 30 operates as described later, or when the trip operation confirmation button 48 provided on the cover 12 is pressed. The trip operation confirmation button 48 is held by the cover 12, and the inclined surface 48a formed at the lower end of the trip operation confirmation button 4
When 8 moves downward, the interlocking bar 47 is rotated counterclockwise around the pivot position. Further, the trip operation confirmation button 48 is biased upward by a button return spring 49 composed of a coil spring, and the upper surface of the trip operation confirmation button 48 stops at a position slightly lower than the upper surface of the cover 12.

An arc extinguishing device 60 is provided on the power source side terminal plate 14. The arc extinguishing device 60 is composed of an insulating frame 61 made of synthetic resin and a magnetic yoke 62 mounted on the insulating frame 61. The yoke 62 is the power supply side terminal plate 1
It is located above the upper surface of No. 4 and is formed in a generally U-shape that is open downward. In addition, a plurality of grid pieces 62a are formed from the two leg pieces so as to form a gap on the side edges of the two leg pieces of the yoke 62 near the terminal screw 15a so that the arc gas can pass through while shielding the arc. Is extended, and the left front opening of the yoke 62 in FIG. 7 is covered by the grid pieces 62a of both leg pieces. That is, the grid pieces 62a are alternately extended from the respective leg pieces in a zigzag manner in the vertical direction, and are separated from each other in the thickness direction of the grid pieces 62a to form gaps between the grid pieces 62a.

As described above, the terminal support piece 14b provided with the fixed contact 21 on the power source side terminal plate 14 is extended from the positioning piece 14a provided at the right end of the power source side terminal plate 14 and is also connected to the power source side terminal plate 14. Because it is located below
A magnetic field generated by a current flowing through the power source side terminal plate 14 through the terminal support piece 14b, the positioning piece 14a and the mounting portion of the terminal screw 15a when the fixed contact 21 and the movable contact 26 are opened to generate an arc. The electromagnetic force acts between the arc and the arc, and the arc is extended in the direction of the terminal screw 15a. Further, above the power source side terminal plate 14, the magnetic field passes through the inside of the yoke 62, so that the electromagnetic force for traveling the arc in the opposite direction does not act. Here, the insulating frame 61 has not only the function of positioning the yoke 62 but also the function of efficiently extinguishing the arc without releasing the pressure applied by the arc gas. The body 10 is provided with an exhaust plate 63 for allowing the arc gas to escape to the outside of the body 10 at a portion corresponding to between the arc extinguishing device 60 and the terminal screw 15a.

Next, the leakage current detecting device 30 will be described. The leakage current detector 30 drives the trip device 50 by determining that it is an abnormal current when an unbalanced current flows in the main circuit, and as shown in FIGS. 8 to 11, the circuit conductors 23a, 23b. , 23c for rotating the main body 31 having the zero-phase current transformer 32 for detecting the flow of the unbalanced current and the interlocking bar 47 in the counterclockwise direction in FIG. 18 when the unbalanced current is detected. And a drive unit 33 having a solenoid 34.

The main body 31 is composed of a printed wiring board on which a zero-phase current transformer 32 and an electronic component 35 constituting an electronic circuit unit for detecting an unbalanced current by the secondary output of the zero-phase current transformer 32 are mounted. The circuit board 36 is formed by being mounted in the sensor case 37. The sensor case 37 is composed of a case body 37a and a case cover 37b. By engaging a coupling claw 38a protruding from the case body 37a with a coupling hole 38b provided in the case cover 37b in a concavo-convex manner, the sensor body 37a and the case cover 37b are connected to each other. Are combined. The zero-phase current transformer 32 is resin-molded and has a positioning protrusion 32a on the outer peripheral portion, and by engaging the positioning protrusion 32a with a positioning notch 37e on the peripheral portion of the opening window 37d formed in the case cover 37b, Sensor case 3
The positioning with respect to 7 is made. Similar to the case cover 37b, an opening window 37c is formed in the case body 37a, and an opening window 36a is also formed in the circuit board 36.
These opening windows 36a, 37c, 37d are the zero-phase current transformer 3
It is formed coaxially with the second opening.

The electric circuit conductors 23a, 23b, 23c are inserted through the opening windows 36a, 37c, 37d, and as shown in FIG. 8, the electric circuit conductors 23a, 23b, 23c are bent in a substantially U shape. It In addition, a pair of insulating separators 81, 82 made of synthetic resin are attached to the sensor case 37 so that the electric circuit conductors 23a, 23b, 23c do not come into contact with each other at the portion inserted into the zero-phase current transformer 32. To be done. Each of the insulating separators 81 and 82 is integrally provided with main plates 81a and 82a facing the outer surface of the sensor case 37 and separating pieces 81b and 82b that are inserted into the zero-phase current transformer 32. Each main piece 8
Mounting protrusions 81c and 82c having a bulged tip are provided on the surface of the la and 82a facing the sensor case 37, and the mounting pins 81c and 82c are press-fitted into the mounting holes 37h provided in the sensor case 37. Thus, the insulating separators 81 and 82 are fixed to the sensor case 37. The separation piece 81b of the insulating separation body 81 is formed in a cross-sectional shape in which a pair of U-shapes are back-to-back and a narrow slit 81d is formed therebetween. The separating piece 82b of the insulating separating body 82 is formed in a substantially U-shaped cross section that is open downward, and has a shape in which a protruding piece 82d that is inserted into the slit 81d of the separating piece 81b is provided on the upper surface of the central piece of the U-shape. It is formed. That is, the two insulating separators 81 and 82 are positioned by the engagement of the slit 81d and the protruding piece 82d. Also, the separation piece 8
Inside each U-shaped part of 1b, 82b, each electric circuit conductor 23
By arranging a, 23b, and 23c, respectively, the electric circuit conductors 23a, 23b, and 23c are insulated from each other.

By the way, as shown in FIGS. 12 and 13, a storage recess 37i is formed on the inner surface of the case body 37a, and two magnetic shield plates 85a made of a magnetic material plate are formed in the storage recess 37i. 85b is arranged. As shown in FIGS. 14 and 15, the magnetic shield plates 85a and 85b are
Insulation plate 8 made of synthetic resin fitted into the case body 37a
6 and the case body 37a. Insulation plate 8
The engaging claw 8 is provided on the surface of the case 6 facing the case body 37a.
The insulating plate 86 is held by the case body 37a by engaging the engaging claws 86a with the engaging holes 37j formed in the case body 37a so as to project from the 6a. Positioning portions 85c are formed on the lower edges of the magnetic shield plates 85a and 85b by cutting and raising to prevent the magnetic shield plates 85a and 85b from being displaced from each other, and to be positioned in the positioning notches 86b provided on the insulating plate 86. By matching the portions 85c, the magnetic shield plates 85a,
The displacement of 85b is prevented. Further, the reverse assembling prevention notches 85d and 86d are formed at the upper and lower edges of the magnetic shield plates 85a and 85b and the insulating plate 86, respectively, and the reverse assembling preventing projections 37k provided on the inner surface of the case body 37a are prevented from being reverse assembling. By matching the notches 85d and 86d, the magnetic shield plates 85a and 85b with respect to the case body 37a
And the reverse assembly of the insulating plate 86 is prevented. Also, the insulating plate 8
6 is a cylindrical portion 86c inserted into the central hole of the zero-phase current transformer 32.
Is provided in the magnetic shield plates 85a, 85b and the insulating plate 86 coaxially with the central hole of the zero-phase current transformer 32.
5e and 86e are formed.

On the other hand, the drive portion 33 is connected to the lid portion 37f projecting upward from the case body 37a.
1 is provided. The lid 37f and the sub case 71 are the lid 3
The coupling hole 37g provided in 7f and the coupling claw 71a provided in the sub case 71 are engaged with each other by projections and recesses to couple them. The sub-case 71 accommodates a circuit board 73 on which a test switch 72 for performing an operation test is housed together with the solenoid 34, and a display button 74 protruding from the upper surface of the body 10 when the solenoid 34 is operated is also provided. Further, a slide switch 75 for switching the sensitivity for operating the solenoid 34 with respect to the unbalanced current is mounted on the circuit board 73. The display button 74 is for the solenoid 34
When the plunger 34a is protruding, it can be engaged with the plunger 34a, and in the engaged state, the upper surface of the display button 74 and the upper surface of the body 10 are substantially flush with each other. When the engagement with the plunger 34a is released in the engagement state with the plunger 34a, it is pushed upward by the push-up spring 76 and protrudes from the upper surface of the body 10. Here, the circuit board 73 is integrated with the circuit board 36 when the electronic component 35 is mounted, as shown in FIG.
After mounting the electronic component 35, it is separated at the position of the sewing machine wire 39 as shown in FIG. 17, and the solenoid 34 is mounted after separation.

Further, the circuit board 36 and the circuit board 73 are electrically connected by the connection line 77, and the connection line 77 is connected before the separation at the position of the sewing machine line 39. As shown in FIG. 8, the connection line 77 is drawn from the sensor case 37 to the sub case 71 through a passage opening 78 formed in the vicinity of the coupling part of the sub case 71 to the sensor case 37. That is, the passage opening 78 is formed between the sub case 71 and the notch opened on the side of the sub case 71 in the lid portion 37f, and the connection line 77 connects both circuit boards 36 and 73. However, by separating the sensor case 37 and the sub case 71, the connection wire 77 can be inserted into the wire opening 78. In the circuit board 36, the connecting portion with the connecting wire 77 is the opening 7 for the wiring.
It is provided in the vicinity of 8 so that the connecting line 77 has a substantially shortest length.

The test switch 72 includes a contact piece 72a which constitutes a contact portion and an operation button 7 which projects from the upper surface of the body 10.
2b, when the operation button 72b is pushed into the body 10, a current is passed through the test winding 32b wound around the zero-phase current transformer 32 for one turn, and the secondary output is the same as when the unbalanced current is generated. To the zero-phase current transformer 32. Therefore, if the operation button 72b of the test switch 72 is pressed while the display button 74 is reset so as to be engaged with the plunger 34a,
It is possible to perform a test as to whether or not the leakage current detection device 30 functions normally.

The tip of the plunger 34a of the solenoid 34 is inserted into a hooking groove 47d formed in the interlocking bar 47,
When the plunger 34a is retracted, the plunger 34a
The hooking pin 34b projecting from the tip of a contacts the peripheral edge of the hooking groove 47d to rotate the interlocking bar 47. That is, the interlocking bar 47 is rotated by the retracting of the plunger 34a, and the trip device 50 is operated.

The earth leakage current detecting device 30 constructed as described above is installed in the body 11 with the case body 37a close to the load side terminal plate 17. Therefore, the magnetic field generated around the heater plate 22 is generated by the magnetic shield plates 85a,
Since it is shielded by 85b, the influence of the magnetic field on the zero-phase current transformer 32 and the electronic component 35 mounted on the circuit board 36 can be prevented.

By the way, in the above-mentioned embodiment, the notch-shaped electric wire insertion opening 18a is provided on both sides of the terminal separating plate 18.
Are formed. As shown in FIG. 21, the connection wire 27 can be passed through the wire insertion opening 18a as necessary, and the output from the electric circuit inside the body 10 (for example,
A signal output for leaving the fact that the leakage current is detected by the leakage current detecting device 30) is passed through the connection electric wire 27 to the body 1
It can be sent to the electric circuit outside 0. In other words, by providing such a wire insertion opening 18a in the terminal separating plate 18, it is not necessary to provide a hole for passing the connection electric wire 27 in the body 10, and it is easy to connect the internal circuit and the external circuit. Become.

[0038]

According to the first aspect of the present invention, the magnetic terminal separator is arranged on one side in the thickness direction of the terminal plate, and the magnetic movable plate is arranged on the other side. By passing the magnetic field formed around the plate through the terminal separator and the movable plate, the movable plate is attracted to the terminal separator.
Since the terminal isolation plate separates the connection between the external circuit and the internal circuit on the terminal board, the internal space of the body is wide compared to the conventional configuration in which the plate is raised. There is an advantage that it can be taken. Also, since the rising portion is not formed by using a flat terminal plate,
It is possible to reduce the height of the body, and since it is not necessary to provide a bent portion on the terminal plate, the shape of the terminal plate becomes simpler than before, and the work of processing the terminal plate becomes easier. Play.

According to the second aspect of the present invention, the holding recess is formed on the bottom surface of the terminal block to accommodate the movable plate. Therefore, a case for restricting the moving direction of the movable plate is not required, resulting in Moreover, the cost can be reduced by reducing the number of parts. Also,
Since the case is unnecessary, the number of parts can be reduced, and the beat noise due to the rattling of the case can be eliminated.

According to the third aspect of the present invention, the terminal separating plate is formed with the electric wire insertion opening, so that the electric circuit installed inside the body is connected to the electric circuit outside the body. Since the electric wire insertion opening through which the electric wire is inserted is formed, there is an advantage that the external electric wire can be introduced through the electric wire insertion opening without additional hole processing.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a main part of an embodiment.

FIG. 2 is a cross-sectional view of a main part of the embodiment.

FIG. 3 is a longitudinal sectional view of a main part of the embodiment.

FIG. 4 is an exploded perspective view of a main part of the embodiment.

FIG. 5 is an exploded perspective view of the embodiment.

FIG. 6 is a perspective view of the embodiment.

FIG. 7 is an exploded perspective view of a main part of the embodiment.

FIG. 8 is an exploded perspective view of a main part of the embodiment.

FIG. 9 is an exploded perspective view of a main part of the embodiment.

FIG. 10 is a front view of a main part of the embodiment.

FIG. 11 is a side view of a main part of the embodiment.

FIG. 12 is an exploded perspective view of a main part of the embodiment.

FIG. 13 is an exploded perspective view of a main part of the embodiment.

FIG. 14 is a horizontal sectional view of an essential part of the embodiment.

FIG. 15 is a longitudinal sectional view of a main part of the embodiment.

FIG. 16 is a perspective view showing a mounted state of components on a circuit board used in an example.

FIG. 17 is a rear view showing a state in which the circuit board used in the example is separated after mounting the components.

FIG. 18 is a cross-sectional view of the example in a closed state.

FIG. 19 is a sectional view of the example in an open state.

FIG. 20 is a cross-sectional view showing a state immediately after the trip operation according to the embodiment.

FIG. 21 is a cross-sectional view of a main part showing another example of use of the embodiment.

FIG. 22 is an exploded perspective view showing a conventional example.

[Explanation of symbols]

 10 body 11f holding recess 13a, 13b terminal block 14 power source side terminal plate 17 load side terminal plate 18 terminal separating plate 18a wire insertion opening 21 fixed contact 26 movable contact 27 connecting wire 42 movable plate 44 return spring 50 trip device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuharu Sonoda, Mie Prefecture, Tsu City, Mie Prefecture, No. 564, Handa, Mie No. 1 Mie Kinzoku Kogyo Co., Ltd. Inside the metal industry

Claims (3)

[Claims] 1. A short circuit current detection device for a circuit breaker, which activates a trip device to open a contact device when a short circuit current passes through a main circuit passing through the contact device, in a terminal block exposed on an outer surface of a body. A flat terminal plate that is placed and forms a part of the main circuit, and one surface in the thickness direction of the terminal plate that is substantially orthogonal to the terminal plate between the external circuit connection part and the internal circuit connection part of the terminal plate. Move in the thickness direction of the terminal board so that the distance between the terminal board and the terminal board made of a magnetic material that is placed in a fixed position on the side of the terminal board and the part of the terminal board that faces the terminal board can be varied. A movable plate made of a magnetic material that is freely arranged, and when the movable plate is attracted to the terminal separator by the magnetic field formed around the terminal plate when a short-circuit current passes through the main circuit, the movable plate moves A circuit breaker characterized by the trip device activating. Short-circuit current detection device. 2. A holding recess, into which the movable plate is inserted so that the movable plate can move back and forth, is formed on the bottom surface of the terminal block, and a return spring for urging the movable plate in a direction separating from the terminal plate is provided between the terminal plate and the movable plate. The short-circuit current detection device according to claim 1, wherein the short-circuit current detection device is arranged. 3. The terminal separator has an electric wire insertion opening through which a connecting electric wire for connecting an electric circuit housed inside the body and an electric circuit outside the body is inserted. The short-circuit current detection device for a circuit breaker according to claim 1 or 2.