JP3046878B2 - 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. 8, the electromagnet device 101 was arranged on the warped side of the bimetal plate 100. The electromagnet device 10
Reference numeral 1 denotes 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.
In addition, since the electromagnet device 101 is arranged on the warp 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]

[Summary of the current detection device of the circuit breaker according to claim 1, a bimetal plate warped in the thickness direction by heating, the bimetal is located on the opposite side of the warp side of the bimetallic plate Electric circuit with current path in the thickness direction of the plate
It has a path conductor having a section, a notch for fitting the electrical path portion of said path conductor and having an opening the disposed opposite the warp side of the bimetal plate to the bimetallic plate in a direction parallel A guide case, a movable magnetic body movably housed in the guide case and positioned on one side of the electric circuit conductor in the notch, and closing the opening of the guide case to interpose the electric circuit conductor. A fixed magnetic body opposed to the movable magnetic body, a return spring housed in the guide case to return and bias the movable magnetic body, and a guide spring along the side surface of the fixed magnetic body in the opening. And a detection piece which is partially movably housed and interlocks with the movable magnetic body.

According to a second aspect of the present invention, there is provided a current detecting device for a circuit breaker.
The guide case has a bottomed cylindrical shape, and the return spring is compressed and interposed between the movable magnetic body and the conductor. The current detection device for a circuit breaker according to claim 3, wherein the guide case has a cylindrical shape having openings at both ends, and one of the openings is closed with the fixed magnetic body, and the other of the openings is more than the other of the openings. A movable magnetic body is movably fitted therein, and the detection piece has a part of the end connected to the movable magnetic body and is hooked on an edge of the opening closed by the fixed magnetic body. The return spring is compressed and interposed between the movable magnetic body and the conductor.

[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 electric circuit, a magnetic flux generated around the electric circuit conductor flows through the fixed magnetic material and the movable magnetic material to attract the movable magnetic material to the fixed magnetic material. The movable magnetic body operates when the spring force becomes larger than the spring force.

In this case, the structure is simple because the magnetic flux generated around the circuit conductor attracts the movable magnetic material, so that the structure is simple. And the movable magnetic body moves parallel to the fixed magnetic body and the conductors of the bimetal plate in parallel with the surface of the bimetal plate, so that the size of the bimetal plate in the thickness direction can be significantly reduced and the size can be reduced. it can. Furthermore, in order to house the movable magnetic body, return spring, detecting piece and fixed magnetic body in the guide case and to insert the conductor into the notch of the guide case, the conductor and the electromagnet device are blocked by caulking or welding. Blocking can be easily performed in comparison.

According to a second aspect of the present invention, the guide case has a bottomed cylindrical shape, and the return spring is compressed and interposed between the movable magnetic body and the conductor. Therefore, in addition to the operation of the first aspect, after the movable magnetic body, the detecting piece, and the return spring are stored in the guide case, the electric circuit conductor is inserted into the cutout portion of the guide case, so that the insertion and assembly can be performed, so that the blocking is further facilitated. become.

According to a third aspect of the present invention, the guide case has a cylindrical shape having openings at both ends, and one of the openings is closed by the fixed magnetic material. The movable magnetic body is movably fitted from the other of the portions, and the detection piece is connected to the movable magnetic body at one end thereof and is connected to the movable magnetic body. Has a hook that hooks on the edge,
Further, since the return spring is compressed and interposed between the movable magnetic body and the electric circuit conductor, the electric circuit conductor is inserted into the notch of the guide case, and the movable magnetic body on which the return spring and the detection piece are mounted is attached to the guide case. It is assembled by inserting the other end of the opening and hooking the hook of the detection piece to the opening to prevent the movable magnetic body from being pulled out, and fixing the fixed magnetic body to one of the openings. It has the same effect.

[0011]

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,
A fixed magnetic body 6, a detecting piece 7, a guide case 8,
It has a return spring 15. The bimetal plate 1 warps in the thickness direction by heating. In the embodiment, the base end of the bimetallic plate 1 is fixed to the bent side of the inner surface of the heater plate 4 which is of an indirectly heated shape and bent into an L-shaped plate by welding.
A gap adjusting screw 5 is provided at the tip end extending from the heater plate 4.
Is provided. 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 are connected to the connecting portion 1 for forming an electric path.
9 and 20, and when a current flows through the heater plate 4 between the connecting portions 19 and 20, the heat generated by the heater plate 4 causes the bimetal plate 1
Is heated, 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 guide case 8 has a thickness of the bimetal plate 1.
Is disposed on the side opposite to the side where the warp direction conductive electrical path conductor 2 which has an opening 22 in a direction parallel to the bimetallic strip 1
It has a notch 23 into which the road is fitted. The guide case 8 of the embodiment is a bottomed rectangular tube having a size that can be inserted between the terminal 9 and the heater plate 4, and has a cutout portion 23 through which the electric circuit conductor 2 passes through the opening 22. Openings 22 on both sides
Is formed in the vicinity of.

The movable magnetic body 3 is movably housed in the guide case 8 and is located on one side of the electric circuit conductor 2 in the notch 23. The movable magnetic body 3 of the embodiment is formed as an iron flat plate. Further, a concave portion 10 is formed at an edge of the movable magnetic body 3 facing the electric circuit conductor 2, and a spring receiving protrusion 11 is formed in the concave portion 10. The fixed magnetic body 6 is provided in the opening 22 of the guide case 8.
And opposes the movable magnetic body 3 with the circuit conductor 2 interposed therebetween. In the embodiment, a fixing claw 14 which is formed of an iron flat plate having the same thickness as that of the movable magnetic body 3, has a concave portion 12 which fits into the electric circuit conductor 2, and is locked on a locking hole 16 on both sides. Is provided.

The return spring 15 is housed in the guide case 8 and urges the movable magnetic body 3 to return. In the embodiment, a coil spring is used as an example. Both ends of the coil spring are engaged with the electric conductor 2 and the spring receiving protrusions 11 and 24 of the movable magnetic body 3 so that the electric conductor 2 is fixed.
And the movable magnetic body 3 are compressed and interposed. The spring force of the return spring 15 is set to a spring force capable of attracting the movable magnetic body 3 against the return spring 15 when a detection current flows through the electric circuit conductor 2.

The detection piece 7 is partly movably housed in the guide case 8 along the side surface of the fixed magnetic body 6 in the opening 22 and is linked to the movable magnetic body 3. The detection piece 7 of the embodiment is attached to one surface of the movable magnetic body 3, and projects the pressing portion 17 at the tip from the opening 22 to the outside through the space between the inner surface of the guide case 8 and the side surface of the fixed magnetic body 6. To assemble, the movable magnetic body 3 was first inserted into the guide case 8, the pressing portion 17 of the detection piece 7 was projected outside from the opening 22 of the guide case 8, and one end of the return spring 15 was inserted into the recess 10. Thereafter, the notch 23 of the case 8 is fitted into the electric circuit conductor 2, and the other end of the return spring 15 is engaged with the spring receiving projection 24 of the electric circuit conductor 2. Furthermore, the fixed magnetic body 6 is inserted into the case 8 from above the circuit conductor 2, the circuit conductor 2 is fitted into the recess 12, and the claws 14 of the fixed magnetic body 6 are locked in the locking holes 16.

In FIG. 2, reference numeral 25 denotes a trip receiving portion of the trip link which is pushed by the operation of the pushing 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, a magnetic flux generated around the electric circuit conductor 2 flows through the fixed magnetic body 6 and the movable magnetic body 3 to attract the movable magnetic body 3 to the fixed magnetic body 6. When the attraction force becomes larger than the spring force of the return spring 15, 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 circuit conductor 2, and the guide case 8 accommodating the movable magnetic body 3 and the fixed magnetic body 6 is made of a bimetal. Since the movable magnetic body 3 is arranged on the opposite side to the warped side of the plate 1 and operates in parallel with the plate surface of the bimetal plate 1 toward the fixed magnetic body 6 and the electric circuit conductor 2, the thickness of the bimetal plate 1 The size can be significantly reduced and the size can be reduced. Guide case 8
The movable magnetic body 3, the return spring 15, the detecting piece 7 and the fixed magnetic body 6 are accommodated in the
Since the electric circuit conductor 2 is fitted into the conductor, the electric circuit conductor and the electromagnet device can be easily blocked as compared with the case where the electric circuit conductor and the electromagnet device are blocked by caulking or welding.

Further, in this embodiment, since the guide case 8 has a bottomed cylindrical shape and the return spring 15 is compressed and interposed between the movable magnetic body 3 and the conductor 2, the movable magnetic body is attached to the guide case 8. 3. After storing the detecting piece 7 and the return spring 15,
By inserting the electric circuit conductor 2 into the notch 23 of the guide case 8, it is possible to insert and assemble, so that it is easier to block.

FIGS. 3 and 4 show this current detecting device applied to a three-pole circuit breaker having a leakage detecting section. Reference numeral 26 denotes a trip link serving also as an interlocking bar having a press receiving portion 25, which performs a trip operation in conjunction with the opening / closing mechanism. The pressing portion 17 operates the pressing receiving portion 25 by pushing up. Reference numeral 28 denotes a bimetal pressure receiving portion provided on the trip link 26. Reference numeral 29 denotes a latch piece of the latch link 30, which 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. Reference numeral 32 denotes a terminal screw screwed into the terminal screw hole 21, and reference numeral 50 denotes a flexible electric wire of an electric path passing through the zero-phase current transformer 31. Other configurations of the earth leakage breaker are known (for example, Japanese Patent Application Laid-Open No. 62-163238), and therefore, the details thereof are omitted.

FIGS. 5 and 6 show a second embodiment of the present invention.
This will be described below. That is, in the current detection device of this circuit breaker, the movable magnetic body 3 rotates with respect to the fixed magnetic body 6. In the first embodiment, the movable magnetic body 3 has one end of the edge of the movable magnetic body 3 facing the fixed magnetic body 6 as a rotation center 33 approaching the fixed magnetic body 6, and the rotation center 3
An arcuate edge 34 is formed on the side opposite to the edge with a radius of curvature centered at 3. The guide case 8 has an arc-shaped edge 3 centered on the rotation center 33 of the movable magnetic body 3 at the bottom.
An arc-shaped sliding surface 35 having a radius of curvature substantially equal to the radius of curvature of 4 is formed so that the arc-shaped edge 34 can slide on the arc-shaped sliding surface 35 when the movable magnetic body 3 rotates. The detection piece 7 has a responsive portion 51 formed by bending an end portion.
1 is mounted on the upper surface of the movable magnetic body 3, and the intermediate portion is fixed magnetic body 6.
The pressing portion 17 at the tip projects out of the case 8 along the side surface of the case 8.

Therefore, when an abnormal current flows through the conductor 2, the movable magnetic body 3 is attracted to the fixed magnetic body 6, and the movable magnetic body 3 rotates about the rotation center 33 in contact with the fixed magnetic body 6. The arcuate edge 34 is attracted to the fixed magnetic body 6 while sliding on the arcuate sliding surface 35. At the same time, the response section 51 of the detection piece 7 performs a detection operation. According to this embodiment, as compared with the first embodiment, the gap is substantially on only one side, so that the sensitivity can be increased. Others are the same as the first embodiment.

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, the guide case 8 is a cylindrical shape having openings 22 and 22 'at both ends, and the opening 22 is closed by the fixed magnetic body 6 and movable from the opening 22'. The magnetic member 3 is movably fitted, and the detection piece 7 has a part of an end connected to the movable magnetic member 3 and a hook portion hooked to an edge of the opening 22 closed by the fixed magnetic member 6. 39 and a return spring 1
Numeral 5 is interposed between the movable magnetic body 3 and the circuit conductor 2 by compression.

In the embodiment, a notch 23 for fitting the electric circuit conductor 2 is formed on the side of the guide case 8 other than the openings 22, 22 '. The fixed magnetic body 6 is fixed by locking the locking projection 35 in the locking hole 36 of the guide case 8. Further, holding pieces 37 extending on both sides of the base end of the detection piece 7 are cutout recesses 38 formed on both sides of the movable magnetic body 3.
The detection piece 7 is connected to the movable magnetic body 3 by being held by the
And the locking portion 39 protrudes outward from the opening 22 on the insertion side of the fixed magnetic body 6, and locks the locking portion 39 to an edge of the opening 22 to return the return spring of the movable magnetic body 3. 15, the movable magnetic body 3 is prevented from being pulled out of the guide case 8. The circuit conductor 2 is formed by welding a connection piece 40 formed integrally with an end of the terminal 9 on a connection piece 41 of a bent one end of a flat inverted U-shaped heater plate 4. The notch 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.

According to this embodiment, the electric circuit conductor 2 is fitted into the notch 23 of the guide case 8 and the movable magnetic body 3 on which the return spring 15 and the detecting piece 7 are mounted is connected to the opening 2 of the guide case 8.
Since the movable magnetic body 3 is prevented from being pulled out by inserting the hooks 39 of the detection piece 7 into the opening 22 by inserting from the 2 'and the fixed magnetic body 6 is fixed to the opening 22, it is assembled. In addition, the bimetal plate 1 and the guide case 8 constituting the electromagnet can be easily formed into blocks.

In each of the above-described embodiments, the trip link 26 is pivotally supported below the free end (point of action) of the bimetal plate 1, and the movable magnetic body 3 moves upward.
When the trip link 26 is operated in the direction approaching the free end, but the trip link 26 is pivotally supported above the action point of the bimetal plate 1, that is, on the side opposite to the base end portion from the free end of the bimetal plate 1, 3 may be arranged on the free end side of the bimetal plate 1 so as to move downward toward the base end side of the bimetal plate 1.

The bimetal plate 1 is of the indirectly heated type using the heater plate 4. However, the bimetallic plate 1 may be of the indirectly heated type which passes current, or the bimetal plate 1 may be replaced with a conductive plate. It may be a direct heat type that allows only current to flow. Further, the electric circuit conductor 2 is connected to the bimetal plate 1 via the heater plate 4, but may be directly connected to the bimetal plate 1.

[0028]

According to the current detecting device for a circuit breaker of the first aspect, the structure is simple because the magnetic flux generated around the circuit conductor attracts the movable magnetic body, and the structure is simple. Since the guide case containing the magnetic material is arranged on the opposite side of the warped side of the bimetal plate and the movable magnetic material moves parallel to the plate surface of the bimetal plate toward the fixed magnetic material and the electric circuit conductor, the plate of the bimetal plate The size in the thickness direction can be significantly reduced, and downsizing can be achieved. Furthermore, in order to house the movable magnetic body, return spring, detecting piece and fixed magnetic body in the guide case and to insert the conductor into the notch of the guide case, the conductor and the electromagnet device are blocked by caulking or welding. There is an effect that blocking can be easily performed in comparison.

According to a second aspect of the present invention, the guide case has a bottomed cylindrical shape, and the return spring is compressed and interposed between the movable magnetic body and the conductor. Therefore, in addition to the effect of the first aspect, after the movable magnetic body, the detecting piece and the return spring are stored in the guide case, the electric circuit conductor is inserted into the cutout portion of the guide case, so that the insertion and assembly can be performed, so that the blocking is further facilitated. become.

According to a third aspect of the present invention, the guide case has a cylindrical shape having openings at both ends, and one of the openings is closed by the fixed magnetic material. The movable magnetic body is movably fitted from the other of the portions, and the detection piece is connected to the movable magnetic body at one end thereof and is connected to the movable magnetic body. Has a hook that hooks on the edge,
Further, since the return spring is compressed and interposed between the movable magnetic body and the electric circuit conductor, the electric circuit conductor is inserted into the notch of the guide case, and the movable magnetic body on which the return spring and the detection piece are mounted is attached to the guide case. It is assembled by inserting the other end of the opening and hooking the hook of the detection piece to the opening to prevent the movable magnetic body from being pulled out, and fixing the fixed magnetic body to one of the openings. It has the same effect.

[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 a sectional view of the assembled state.

FIG. 7 is an exploded perspective view of the third embodiment.

FIG. 8 is a perspective view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bimetal board 2 Circuit conductor 3 Movable magnetic body 6 Fixed magnetic body 7 Detecting piece 8 Guide case 15 Return spring 22 Opening 23 Notch

──────────────────────────────────────────────────続 き Continuation of the front page (56) References: JP-A 53-89575 (JP, U) JP-A 37-15359 (JP, Y1) JP-A 41-20359 (JP, Y1) JP-A 47- 42294 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 73/48 H01H 71/40

Claims (3)

(57) [Claims] 1. A path portion having a bimetal plate warped in the thickness direction, the warpage side and position to the current path in the thickness direction of the bimetal plate on an opposite side of the bimetallic plate by heating
A path conductor having a guide with a notch for fitting the electrical path portion of said path conductor and having an opening the disposed opposite the warp side of the bimetal plate to the bimetallic plate in a direction parallel A case, a movable magnetic body movably housed in the guide case and positioned on one side of the electric circuit conductor in the notch, and closing the opening of the guide case to interpose the electric circuit conductor. A fixed magnetic body opposed to the movable magnetic body, a return spring housed in the guide case for returning and biasing the movable magnetic body, and a return spring in the guide case along a side surface of the fixed magnetic body in the opening. A current detecting device for a circuit breaker, comprising: a detecting portion that is movably housed and is linked to the movable magnetic body. 2. The current detecting device for a circuit breaker according to claim 1, wherein said guide case is a bottomed cylindrical shape, and said return spring is compression-interposed between said movable magnetic body and said electric circuit conductor. 3. The guide case has a cylindrical shape having openings at both ends. One of the openings is closed by the fixed magnetic body, and the movable magnetic body is movably fitted from the other of the openings. The detection piece has a hook portion that connects the end of the part to the movable magnetic body and hooks on an edge of the opening that is closed by the fixed magnetic body; 2. The current detecting device for a circuit breaker according to claim 1, wherein a spring is compressionly interposed between the movable magnetic body and the conductor.