JP3126489B2 - Circuit breaker current detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current detecting device for a circuit breaker.

[0002]

2. Description of the Related Art Conventional examples (for example, JP-A-62-163238)
As shown in FIG. 11, an electromagnet device 101 was arranged on a warped side of a bimetal plate 100. Electromagnet device 1
01 is a coil 102, a yoke 103, a plunger 104
And a return spring 105.

[0003]

However, in the current detecting device of the circuit breaker, the structure of the electromagnet device 101 is complicated, and the bimetal plate 100 is long in the plate thickness direction.
Moreover, since the electromagnet device 101 is arranged on the warped side of the bimetal plate 100 and requires a space for warping the bimetal plate 100, there is a disadvantage that the overall size of the bimetal plate 100 in the plate thickness direction becomes large.

Some electromagnet devices operate in a direction perpendicular to the bimetal plate, but a space for operation is required, and the size of the electromagnet device is increased. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a circuit breaker current detecting device which has a simple structure and can be reduced in size.

[0005]

According to a first aspect of the present invention, a current detecting device for a circuit breaker includes a bimetal plate warped in a thickness direction by heating, and a bimetal plate located on a side opposite to the warped side of the bimetal plate. A circuit conductor having an electric circuit portion having a current path in the thickness direction of the plate, and a magnetic flux generated by a current flowing through the electric circuit portion of the electric circuit conductor arranged on the side opposite to the warped side of the bimetal plate, and a movable magnetic member linearly moves in parallel to the plate surface of the bimetal plate, the movable magnetic
Facing the conductive body via the electric circuit conductor, and
A fixed magnetic body that attracts the movable magnetic body, a return spring that returns and urges the movable magnetic body, and a notch through which the electric circuit conductor passes.
Having the movable magnetic body slidably supported and fixed
And a case for fixing the magnetic body .

According to a second aspect of the present invention, there is provided a current detecting device for a circuit breaker.
In claim 1 , the movable magnetic body and the fixed magnetic body each have a concave portion at the opposing edge thereof, and the electric circuit conductor is disposed substantially at the center of a gap of the concave portion.
The current detecting device for a circuit breaker according to claim 3 is provided by heating.
Bimetal plate warped in the thickness direction and in front of this bimetal plate
The thickness direction of the bimetal plate located on the side opposite to the warp side
A circuit conductor having a circuit section having a current path in
An inverted U-shaped fixed magnetic body provided on a road conductor,
An L-shape attached along part of the outer surface of the magnetic body
A hinge portion at one end adjacent to one end of the fixed magnetic body.
A support piece provided with a guide portion at the other end and a hinge portion
The proximal end is pivotally supported and the distal end is in contact with the other end of the fixed magnetic body.
A movable magnetic body opposing so that it can be separated
A base end portion is pivotally supported by the distal end portion, and a distal end portion is the guide portion.
The detection piece slidably guided by the
A return spring that urges return to a position away from the fixed magnetic body
It is provided with .

[0007]

According to the current detecting device for a circuit breaker of the present invention, when an overcurrent flows in the electric circuit, the bimetal plate is heated, so that the bimetal plate operates to warp. When an abnormal current such as a short-circuit current flows in the circuit, the movable magnetic body is attracted by magnetic flux generated around the circuit conductor, but when the attractive force becomes larger than the spring force of the return spring, the movable magnetic body is moved. Operate.

[0008] In this case, a simple structure for the configuration for sucking more movable magnetic body fixed magnetic body magnetic flux <br/> occurring around the path conductors, the suction force of the magnetic efficiency movable magnetic body
The sensitivity can be increased and increased. Movable magnetic material and fixed magnet
Since the movable body moves parallel to the surface of the bimetal plate and the movable body moves parallel to the surface of the bimetal plate, the size of the bimetal plate in the thickness direction can be significantly reduced, and the size can be reduced. it can. According to the current detection device for a circuit breaker of claim 2, in claim 1 , the movable magnetic body and the fixed magnetic body each have a concave portion on the opposite edge thereof, and the electric circuit conductor is substantially the same as the gap of the concave portion. Since it is arranged at the center, in addition to the function of claim 1 , leakage magnetic flux that does not pass through the movable magnetic body and the fixed magnetic body can be eliminated, so that the magnetic efficiency can be further improved and the attractive force of the movable magnetic body can be increased. , High sensitivity.

According to a third aspect of the present invention, there is provided the same function as that of the first aspect.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. That is, the current detecting device of the circuit breaker includes a bimetal plate 1, a circuit conductor 2,
And a return spring 15. The bimetal plate 1 warps in the thickness direction by heating. In the embodiment, the base end portion of the bimetal plate 1 is fixed to the bent side of the inner side surface of the heater plate 4 bent into an L-shaped plate by welding, and the distal end portion extended from the heater plate 4. Is provided with a gap adjusting screw 5. The bimetal plate 1 is attached to the heater plate 4 so as to warp in a direction away from the heater plate 4. Then, both ends of the heater plate 4 become connection portions 19 and 20 for forming electric paths, and the heater plate 4 is provided between the connection portions 19 and 20.
When a current flows through the bimetal plate 1, the bimetal plate 1 is heated by the heat generated by the heater plate 4, and the bimetal plate 1 performs a warp operation. The warp operation of the bimetal plate 1 when an overcurrent occurs is defined as a detection operation.

The electric circuit conductor 2 is arranged in the thickness direction of the bimetal plate 1.
In the thickness direction of the bimetal plate 1 located on the side opposite to the side
Has an electric circuit portion having a current path . That is, in the embodiment, the connection portion of the terminal 9 to the heater plate 4 is taken as an embodiment, and the terminal 9 and the electric circuit conductor 2 serving as the connection portion are substantially Z-connected through the plate portion 13 parallel to the bimetal plate 1. It is bent in the shape of a letter, and the bent end portion 18 of the electric circuit conductor 2 is attached to the surface of the connection portion 19 of the heater plate 4 on the side opposite to the bimetal plate 1 by welding. 21 is a terminal screw hole, and 24 is a spring receiving projection (FIG. 2). Therefore, the electric circuit flows through the path of the terminal 9, the plate portion 13, the electric circuit conductor 2, and the connecting portions 19 and 20 of the heater plate 4.

The movable magnetic body 3 is in the thickness direction of the bimetal 1.
Is attracted to the side of the magnetic flux generated by the current flowing in the electrical path portion of the deployed path conductor 2 on the opposite side warped bimetal plate 1
It operates parallel to the plate surface. Movable magnetic body 3 in the embodiment is <br/> formed into an iron flat plate having a thickness which is loosely inserted into a gap corresponding to the length of the path conductors 2 between the plate portion 13 and the heater plate 4 of the terminal 9 I have. Also, the conductor 2 is connected to the movable magnetic body 3.
A fixed magnetic body 6 having a flat iron plate as an example is provided therebetween. Concave portions 10 and 12 are formed on opposing edges of the movable magnetic body 3 and the fixed magnetic body 6, respectively, and a spring receiving protrusion 11 is formed in the concave portion 10. The movable magnetic body 3 has a thin detection piece 7 attached to one side thereof, a front end extending to a rear end side of the fixed magnetic body 6, and a pressing portion 17 formed at the front end by bending. Further, the movable magnetic body 3 and the fixed magnetic body 6
These are housed in a case 8 with the circuit conductors 2 interposed between 0 and 12. The case 8 has a size that can be inserted between the terminal 9 and the heater plate 4.
A notch 23 through which the air flows is formed. The movable magnetic body 3 is movably inserted into the case 8 and the pressing portion 17 is
From the outside. The notch 23 has the conductor 2
And the fixed magnetic body 6 is inserted into the case 8 with the electric circuit conductor 2 interposed therebetween. To fix the fixed magnetic body 6, claws 14 are provided on both sides of the fixed magnetic body 6, and locking holes 16 for locking the claws 14 are formed on both sides of the case 8.

The return spring 15 urges the movable magnetic body 3 to return. In the embodiment, a coil spring is used as an embodiment,
Both ends of the conductor conductor 2 and the spring receiving projections 11 of the movable magnetic body 3
24. The return spring 15 is connected to the conductor 2
The spring force is set to a spring force that can attract the movable magnetic body 3 against the return spring 15 when the detection current flows. FIG.
In the figure, reference numeral 25 denotes a press receiving portion of the trip link pressed by the operation of the pressing portion 17.

According to this embodiment, when an overcurrent flows in the electric circuit, the bimetal plate 1 is heated, so that the bimetal plate 1 operates so as to warp. When an abnormal current such as a short-circuit current flows in the electric circuit, the movable magnetic body 3 is attracted by the magnetic flux generated around the electric circuit conductor 2, and the attractive force is reduced by the return spring 1.
When the spring force exceeds 5, the movable magnetic body 3 operates.

In this case, the structure is simple because the movable magnetic body 3 is attracted by the magnetic flux generated around the electric circuit conductor 2, and the movable magnetic body 3 is arranged on the side opposite to the warped side of the bimetal plate 1. In addition, since the bimetal plate 1 operates in parallel with the plate surface, the size of the bimetal plate 1 in the plate thickness direction can be significantly reduced, and downsizing can be achieved. FIGS. 3 and 4 show this current detection device applied to a three-pole circuit breaker having a leakage detection unit. 26 is a pressure receiving portion 25
A trip link which also serves as an interlocking bar, is supported by a shaft 27 on the base end side of the free end of the bimetal plate 1, and the pressing portion 17 pushes up the pressing receiving portion 2.
5 is working. Reference numeral 28 denotes a bimetal pressure receiving portion provided on the trip link 26. 29 is a latch link 30
, And operates in conjunction with the rotation of the trip link 26. Numeral 31 denotes a zero-phase current transformer for detecting electric leakage, which is arranged on the warped side of the bimetal plate 1 of the current detecting device. 32 is a terminal screw screwed into the terminal screw hole 21;
Reference numeral 50 denotes a flexible electric wire of an electric circuit passing through the zero-phase current transformer 31. Other configurations of the earth leakage breaker are known (for example,
62-163238), so details are omitted here.

A second embodiment of the present invention will be described with reference to FIG. That is, in the current detecting device of this circuit breaker, the bimetal plate 1 is of the indirect heating type in the first embodiment. That is, the flexible electric wire 33 is connected to the free end of the bimetal plate 1 without connecting the electric circuit to the connection portion 20 of the heater plate 4 of the first embodiment. Therefore, a current flows through the path of the terminal 9, the conductor 2, the heater plate 4, the bimetal plate 1, and the flexible electric wire 33, and the bimetal plate 1 is indirectly heated by the heater plate 4 and is heated by the heat generated by the bimetal plate 1 itself. You. Others are the same as the first embodiment.

As a modification of this embodiment, when the heater plate 4 is formed of a conductive plate, the bimetal plate 1 becomes a direct heat type only by heat generation. A third embodiment of the present invention will be described with reference to FIG. That is, in the current detecting device of this circuit breaker, a notch 23 for fitting the electric circuit conductor 2 is formed on the side of the case 8 having openings 22 and 22 'at both ends, and is fixed from the openings 22 and 22'. The magnetic body 6 and the movable magnetic body 3 are inserted. In this case, the fixed magnetic body 6 is fixed by locking the locking projection 35 to the locking hole 36 of the case 8. In addition, the movable magnetic body 3 holds the holding pieces 37 extending on both sides of the base end of the detection piece 7 in the cutout recesses 38 formed on both sides of the movable magnetic body 3, and presses the tip of the detection piece 7. 17, the locking portion 39 is bent so that the locking portion 39 projects outward from the opening 22 on the insertion side of the fixed magnetic body 6, and the locking portion 39 is locked to the edge of the opening 22. Thus, the movable magnetic body 3 supports the return state by the return spring 15. The circuit conductor 2 is formed by welding a connection piece 41 formed integrally with an end of the terminal 9 with a connection 41 at one bent end of the flat inverted U-shaped heater plate 4 being welded. The part 23 is externally fitted and held. The base end of the bimetal plate 1 is connected to the other end of the heater plate 4 by welding.

When the indirectly heated type is used, an electric circuit is connected to the bimetal connection side of the heater plate 4, and when the indirectly heated type is used, a flexible electric wire of the electric circuit is connected to the free end of the bimetal plate 1. In the case of using a thermal type, the heater plate 4 is changed to a conductive plate in the indirect heating type. Others are the same as the first embodiment. A fourth embodiment of the present invention will be described with reference to FIGS. That is, the current detection device of this circuit breaker
An inverted U-shaped fixed magnetic body 6 is provided on the circuit conductor 2, and an L-shaped support piece 44 is attached to the fixed magnetic body 6. For example, a T-shaped support piece 44 is attached to one end of the support piece 44 adjacent to the end of the fixed magnetic body 6. And a guide part 46 is provided at the other end. The movable magnetic body 3 has a T-shaped hole at the base end 47 that can be rotatably fitted to the hinge part 45, and has a L-shaped rod at the front end for bearing the base end of the detection piece 7 as an example. The tip of the detection piece 7 is slidably guided by the guide part 46, and the pressing part 17 of the detection piece 7 faces the pressure receiving part 25. Further, a return spring 15 is provided between the electric circuit conductor 2 and the movable magnetic body 3. In addition, the connection part 18 of the electric circuit conductor 2 gets over the heater plate 4 and is welded to the bimetal mounting side,
The bimetal plate 1 is disposed on the side of the connecting portion 18 of the heater plate 4. Others are the same as the first embodiment.

A fifth embodiment of the present invention will be described with reference to FIG. That is, the current detection device of this circuit breaker
In the first embodiment, the electric circuit conductor 2 is arranged substantially at the center of the gap between the concave portions 10 and 12 of the movable magnetic body 3 and the fixed magnetic body 6. In this case, the case conductor 8 is set so that the conductor 2 is positioned at the center between the concave portions 10 and 12 of the movable magnetic body 2 and the fixed magnetic body 6.
, The depth of the notch 23, the fixed position of the fixed magnetic body 6, and the like.

[0020] The respective embodiments was or is the trip link 26 is rotatably supported by the lower than the free end of the bimetal plate 1 (action point), as the movable magnetic body 3 operates the push-up upwards, approaching the free end When the trip link 26 is pivotally supported above the action point of the bimetal plate 1, that is, on the opposite side of the free end of the bimetal plate 1 from the base end, the movable magnetic body 3 is moved to the bimetal plate 1. 1 and may be configured to move downward toward the base end of the bimetal plate 1.

[0021]

According Effect of the Invention] the current detection device of the circuit breaker according to claim 1, the structure for the configuration for sucking more movable magnetic body fixed magnetic body magnetic flux generated around the path conductors is simple, magnetic High sensitivity that can efficiently increase the attractive force of the movable magnetic material
Can be In addition, since the movable magnetic material and the fixed magnetic material are arranged on the opposite side of the warped side of the bimetal plate and the movable magnetic material operates parallel to the plate surface of the bimetal plate, the size of the bimetal plate in the thickness direction can be significantly reduced. There is an effect that the size can be reduced.

According to a second aspect of the present invention, in the first aspect , the movable magnetic body and the fixed magnetic body each have a concave portion at an opposite edge thereof, and the electric circuit conductor is formed of the concave portion. Because it is located almost in the center of the gap,
In addition to the effect of the first aspect, since the leakage magnetic flux that does not pass through the movable magnetic body and the fixed magnetic body can be eliminated, the magnetic efficiency can be further improved, the attraction force of the movable magnetic body can be increased, and the sensitivity can be increased. According to the circuit breaker current detecting device of the third aspect, the same effect as that of the first aspect is obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a first embodiment of the present invention.

FIG. 2 is a sectional view of the assembled state.

FIG. 3 is a partial cross-sectional side view of the circuit breaker.

FIG. 4 is a partially cutaway plan view of the circuit breaker.

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

FIG. 6 is an exploded perspective view of the third embodiment.

FIG. 7 is a front view of a fourth embodiment.

FIG. 8 is a partial cross-sectional side view of the circuit breaker.

FIG. 9 is a partially cutaway plan view of the circuit breaker.

FIG. 10 is a sectional view of a fifth embodiment.

FIG. 11 is a perspective view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bimetal plate 2 Circuit conductor 3 Movable magnetic body 6 Fixed magnetic body 10, 12 Concavity 15 Return spring

Continuation of the front page (56) References JP-B-63-22007 (JP, B1) JP-B-37-15359 (JP, Y1) JP-B-41-20359 (JP, Y1) JP-B-47-42294 (JP , Y1) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01H 73/48

Claims (3)

(57) [Claims] A bimetal plate warped in a thickness direction by heating, a circuit conductor having a current path portion located on a side opposite to the warped side of the bimetal plate and having a current path in a thickness direction of the bimetal plate; a movable magnetic member linearly moves in parallel with the warps side as disposed opposite plate surface of the bimetal plate is attracted to the magnetic flux generated by current flowing through the electrical path portion of said path conductor of said bimetallic strip, this Movable magnetism
Opposes the body via the conductor, and
It has a fixed magnetic body that draws the moving magnetic body, a return spring that returns and urges the movable magnetic body, and a notch through which the electric circuit conductor passes.
To slidably support the movable magnetic body and
And a case for fixing the body . Wherein said movable magnetic body and the fixed magnetic body has a recess respectively on its opposite edges, said path conductors of the circuit breaker according to claim 1, characterized in that arranged substantially at the center of the gap of the recess Current detector. 3. A bimetal that warps in the thickness direction by heating.
Plate and a side opposite to the warped side of the bimetal plate.
An electric circuit portion having a current path in the thickness direction of the bimetal plate
And a reverse U-shape provided on the circuit conductor
Along the fixed magnetic body and part of the outer surface of this fixed magnetic body
One end of the fixed magnetic body,
Hinge at one end and guide at the other end
The support piece and the hinge part have a base end pivotally supported and a tip end
Movable opposing the other end of the fixed magnetic body so as to be able to approach and separate
A magnetic body and a base end supported by the distal end of the movable magnetic body.
And the tip was slidably guided by the guide.
The detection piece and the movable magnetic body are separated from the fixed magnetic body.
A current detecting device for a circuit breaker, comprising: a return spring for biasing the return to a position .