JPH1050194A - Trip gear for breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a trip gear for a breaker, which has sufficient attraction force regardless of the distance of a gap part, and surely cuts off the cable way. SOLUTION: This trip gear for a breaker is provided with its cable way 1, a yoke in a U shape, which is provided with a bottom surface part 3a, side surface parts 3b and 3c extened from both the ends of the bottom surface part, and faced to each other where its cable way is enclosed by the bottom surface part 3a and the side surface parts 3b and 3c, and with a movable iron piece 13 which is attracted in by the yoke magnetized when eddy current flows in the cable way so as to allow the cable way to be cut off. In this case, a attractive part 14 where the smaller distance interspaced from the movable iron piece is more subjected to the smaller area of a gap part through which magnetic fluxes pass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker tripping device for operating a breaker by detecting an overcurrent in a relatively large area.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. FIG. 7 is a sectional view of the tripping device of the breaker.
FIG. 8 is a sectional view of the yoke. 9 and 10 are sectional views of another yoke. FIG. 11 is an explanatory diagram showing the relationship between the suction force of the yoke and the distance of the gap.

As shown in FIG. 7, a tripping device for a breaker includes a bimetal 1 corresponding to an electric circuit, a movable iron piece 2, a yoke 3, and a return spring 4.

[0004] The movable iron piece 2 is a magnetic band-shaped body, has shaft portions 5 on both sides, and has a locking receiving portion 6 for tripping.
And a bimetal interlocking section 7.

The bimetal 1 is a direct heat type bimetal for detecting an overcurrent. The bimetal 1 is disposed to face the movable iron piece 2 and engages with the bimetal interlocking portion 7. When an overcurrent flows, the movable iron piece is bent by heat generation. 2 is driven against the spring force of the return spring 4. The upper end of the bimetal 1 is fixedly connected to the load terminal 8 a as a fixed portion and is electrically and mechanically connected. The lower end of the bimetal 1 is used as an operating portion to lock the bimetal interlocking portion 7 and to be connected to the lead wire 9. .

The yoke 3 has a substantially U-shaped cross section as shown in FIG.
And a side surface 3b, 3c extending from both ends of the bottom surface 3a. The bottom surface 3a and the side surfaces 3b and 3c have substantially the same thickness. The yoke 3 is for detecting overcurrent in a relatively large area. When the overcurrent in a relatively large area flows through the bimetal 1, the return spring 4 is used.
Is a magnetic material that attracts the movable iron piece 2 against the spring force of the magnetic iron.

[0007] The return spring 4 is driven by the spring force to move the movable iron piece 2.
To return in a direction away from the bimetal 1.

Reference numerals 8a and 8b denote load terminals and reference numeral 10 denotes a cradle serving as a latch link to be locked in the locking receiving portion.

The lead wire 9 and the load terminal 8 which are electric paths
When an overcurrent flows through the bimetal 1 through the a and 8b, the bimetal 1 gradually bends in the direction of arrow A, and the movable iron piece 2 is pressed against the bimetal 1 at the bimetal interlocking portion 7. And the movable iron piece 2 rotates counterclockwise B direction against the spring force of the return spring 4 about the shaft portion 5 as an axis,
The cradle 10 is removed from the lock receiving portion 6. When the movable iron piece 2 is tripped and the cradle 10 is tripped, the cradle 10 rotates counterclockwise, and the reversing spring 1
Since 1 is inverted to open the movable contact 12, the electric circuit is cut off.

On the other hand, when an overcurrent in a relatively large area flows through the electric circuit, as shown in FIG. 8, magnetic flux generated around the bimetal 1 by the current flowing through the bimetal 1 causes a gap between the yoke 3 and the movable iron piece 2 and the gap therebetween. It flows through a magnetic path C composed of a portion G. Then, the movable iron piece 2 is instantly sucked into the yoke 3 faster than the bending operation of the bimetal 1 so that the gap G becomes smaller. Due to the suction, the movable iron piece 2 rotates counterclockwise in the direction B around the shaft 5, and the cradle 10 locked on the movable iron piece 2 is pulled off. Then, the movable iron piece 2 is tripped to operate the cradle 10.
When the cradle 10 is tripped, the cradle 10 rotates counterclockwise, and the reversing spring 11 reverses to drive the movable contact 12 so that the electric path is cut off.

As another tripping device for a breaker, as shown in FIG. 9, one of the portions of the movable iron piece 13 facing the yoke 3 is rotatably engaged with the yoke 3. In some cases, a gap G is provided on the other side so that the movable iron piece 13 opens and closes.

Further, as shown in FIG. 10, there is a type in which an opposing piece 3d for enlarging the area of the portion of the yoke 3 opposing the movable iron piece 13 is provided.

[0013]

The above-mentioned FIG.
In a breaker tripping device as shown in FIG.
When the distance of the gap G is large, the suction force is reduced.
That is, when the distance of the gap portion G is large, the magnetic flux density B is in the unsaturated region in the magnetization curve, so that the magnetic flux φ is proportional to the gap cross-sectional area S. However, since the gap cross-sectional area S itself is small, the magnetic flux φ Is small, and as a result, the suction force F represented by the following equation (1) is small.

[0014]

(Equation 1)

Here, μ0 is the magnetic permeability of air. On the other hand, when the movable iron piece 2 or the movable iron piece 13 is drawn and the distance of the gap G is reduced, the suction force increases. That is, when the distance of the gap G is small, the magnetic flux density B
Is in the saturation region of the magnetization curve, so that the magnetic flux φ is a saturated value irrespective of the cross-sectional area S of the gap. Therefore,
The suction force F expressed by the equation (1) increases as the gap section S decreases, and the tripping devices in FIGS. 8 and 9 have a large suction section F because the gap section S is small.

Further, in the breaker tripping device as shown in FIG. 10, even if the distance of the gap G is large, the suction force is relatively large. That is, when the distance of the gap G is large, the magnetic flux density B is in the unsaturated region of the magnetization curve, so that the magnetic flux φ is proportional to the gap cross-sectional area S, but the gap cross-sectional area S is provided with the facing piece 3d. Great for Therefore, the magnetic flux φ is large because the cross-sectional area S of the gap is large, and as a result, the attractive force F represented by the equation (1) is large.

On the other hand, even if the movable iron piece 13 shown in FIG. 10 is drawn and the distance of the gap G is reduced, the suction force does not increase so much. That is, when the distance of the gap G is small, the magnetic flux density B is in a saturation region of the magnetization curve, and thus the magnetic flux φ becomes a saturated value regardless of the gap cross-sectional area S. Therefore, although the suction force F represented by the formula (1) increases as the gap cross-sectional area S decreases, the tripping device in FIG. 10 does not increase so much because the gap cross-section S is large.

As described above, in the trip device having a small gap area S, as shown by a curve C1 in FIG.
When the distance of the gap G is large, the suction force F is inferior, but when the distance of the gap G is small, the suction force F increases. In a tripping device having a large gap area S, as shown by a curve C2 in FIG. 11, the suction force F is large when the distance of the gap G is large, but the suction force is small when the distance of the gap G is small. The force F is inferior.

Therefore, if the area of the gap is increased, the suction force is inferior when the distance of the gap is reduced, and if the area of the gap is reduced, the suction is inferior when the distance of the gap is increased. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object the purpose of having a sufficient suction force irrespective of the distance of the gap portion to reliably cut off the electric circuit. To provide a breaker trip device.

[0021]

According to the present invention, in order to solve the above-mentioned problems, according to the first aspect of the present invention, an electric path is extended from both ends of the bottom surface and the bottom surface and opposed to each other. A U-shaped yoke having a side surface portion and enclosing an electric circuit by a bottom surface portion and a side surface portion, and opposing a tip of a side surface portion of the yoke, is attracted to the yoke excited when an overcurrent flows through the electric circuit, thereby forming an electric circuit. In the tripping device of a breaker having a movable iron piece to be interrupted, a suction unit is provided at a tip of a side portion of the yoke, the gap part area through which a magnetic flux passes decreases as the distance from the movable iron piece decreases. Is what you do.

According to a second aspect of the present invention, the suction portion extends from the tip of the side portion of the yoke at a predetermined angle in the direction of the other side portion and the bottom portion. is there.

According to a third aspect of the present invention, the suction portion is provided at a predetermined angle substantially parallel to the movable iron piece when the movable iron piece is most separated from the yoke. .

In the invention according to claim 4, the electric circuit includes:
A U-shaped yoke extending from both ends of the bottom surface and the bottom surface and facing each other and having a U-shaped yoke surrounding the electric circuit by the bottom surface and the side surface; In a breaker trip device having a movable iron piece that is attracted by a yoke excited when a current flows and interrupts an electric circuit, a tip of one side of the yoke extends in a direction substantially parallel to a bottom surface toward another side surface. The provided opposing piece is provided, and on the movable iron piece,
It is characterized in that a movable iron piece side suction section is provided in which the smaller the distance from the opposing piece, the smaller the area of the gap through which the magnetic flux passes.

According to a fifth aspect of the present invention, when the movable iron piece is closed by the yoke, the movable iron piece side suction portion has a predetermined angle with respect to the opposing piece.

According to a sixth aspect of the present invention, the movable iron piece side suction portion is provided at a predetermined angle which is substantially parallel to the opposing piece when the movable iron piece is most separated from the yoke. It is a feature.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a breaker trip device according to the present invention will be described with reference to FIGS. 1 to 3, and a second embodiment will be described with reference to FIGS.

[First Embodiment] FIG. 1 is a perspective view of a device for tripping a breaker. FIG. 2 is a cross-sectional view of the breaker tripping device with the movable iron piece opened. FIG. 3 is a sectional view of the breaker trip device in a state where the movable iron piece is closed. In FIGS. 1 to 3, the same reference numerals are given to the same portions as those of the breaker tripping device described in the above-described conventional technique, and the detailed description of the same portions will be omitted.

The breaker tripping device according to the present embodiment shown in FIG. 1 is different from the breaker tripping device described in the above-mentioned prior art and has the following features.

That is, the suction piece 14 is formed by bending the opposing piece 3d of the breaker tripping device described with reference to FIG. 10 in the prior art at a predetermined angle toward the bottom surface 3a.

As shown in FIG. 2, when the movable iron piece 13 is most separated from the yoke 3, the suction section 14 is substantially parallel to the yoke facing surface 13a of the movable iron piece 13. The entire opposing surface 14 has a gap area S1 through which the magnetic flux φ passes. On the other hand, as shown in FIG. 3, when the movable iron piece 13 is sucked by the yoke 3 and the distance of the gap G is reduced, the suction part 14 forms a predetermined angle with the movable iron piece 13 and the suction part 14 Tip 14 of
a is apart from the movable iron piece 13, and the base end 14 b is
Close to 3. Since the magnetic flux φ has a property of passing through a small gap portion, in this state, the magnetic flux φ passes through the base end portion 14b. Therefore, the gap area S2 is a small area near the base end 14b of the facing surface of the suction section 14, and is smaller than the gap area S1.

Strictly speaking, if the movable iron piece 13 is slightly separated from the opened state, the yoke-facing surface 13a and the facing surface of the suction portion 14 have a certain angle, and the distal end portion 14a and the movable iron piece 13 Distance between the base end portion 14b and the movable iron piece 1
3, but since the distance between the movable iron piece 13 and the suction portion 14 as a whole is large, the influence of the fixed angle is small.

Next, the operation of the circuit breaker tripping device constructed as described above will be described. First, when an overcurrent in a relatively large area flows through the electric circuit, a magnetic flux generated around the bimetal 1 by the current flowing through the bimetal 1 flows through the magnetic path C including the yoke 3, the movable iron piece 13, and the gap G between them. Then, the movable iron piece 13 is instantaneously sucked into the yoke 3 faster than the bending operation of the bimetal 1 so that the gap G becomes smaller.

At this time, when the movable iron piece 13 is separated from the suction portion 14 of the yoke 3 and the distance of the gap is large, the suction force F is large because the gap area S1 is large. Is attracted and the moving iron piece 1
When 3 is close to the suction unit 14 and the distance of the gap is reduced, the gap area S2 is reduced and the suction force F is increased.

Therefore, even if the movable iron piece 13 is separated from the suction part 14 of the yoke 3, or if the movable iron piece 13 is close to the suction part 14 of the yoke 3, the suction force F is large, and the electric circuit can be reliably and quickly performed. Can be shut off.

[Second Embodiment] FIG. 4 is a perspective view of a device for tripping a breaker. FIG. 5 is a sectional view of the breaker trip device in a state where the movable iron piece is opened. FIG. 6 is a sectional view showing a state in which the movable iron piece of the breaker trip device is closed. 4 to 6, the same reference numerals are given to the same parts as those of the breaker tripping device described in the above-described conventional technique, and the detailed description of the same parts will be omitted.

The feature of the breaker tripping device of this embodiment shown in FIG. 1 which is different from that of the breaker tripping device described in the above prior art is as follows.

That is, the substantially central portion of the movable iron piece 13 of the breaker tripping device described with reference to FIG. 10 in the prior art is bent at a predetermined angle to the yoke 3 side so that the movable iron piece side suction portion 15 is formed. This is the configuration.

The opposing surface 15a of the movable iron one-side suction unit 15 is
As shown in FIG. 5, when the movable iron piece 13 is separated from the yoke 3, it is parallel to the facing surface 3e of the facing piece 3d, and in this state, the entire surface of the facing surface 15a is a gap portion through which the magnetic flux φ passes. The area becomes S3. On the other hand, as shown in FIG. 6, the movable iron piece 13 is attracted to the yoke 3 and the gap G
Is smaller, the opposing surface 15a of the movable iron piece side suction part 15 and the opposing surface 3e of the opposing piece 3d form a predetermined angle, and the opposing surface 15a at the distal end 3f of the opposing piece 3d. The distance to the opposing surface 3e is larger than the distance between the opposing surface 15a and the opposing surface 3e at the base end 3g. Since the magnetic flux φ has the property of passing through a small gap, the magnetic flux φ passes through the base end 3g in this state. Accordingly, the gap area S4 is a small area of a part of the facing surface 15a facing the base end 3g, and is smaller than the gap area S3.

Next, the operation of the circuit breaker tripping device constructed as described above will be described. First, when an overcurrent in a relatively large area flows through the electric circuit, a magnetic flux generated around the bimetal 1 by the current flowing through the bimetal 1 flows through the magnetic path C including the yoke 3, the movable iron piece 13, and the gap G between them. Then, the movable iron piece 13 is instantaneously sucked into the yoke 3 faster than the bending operation of the bimetal 1 so that the gap G becomes smaller.

At this time, when the movable iron piece side suction portion 15 of the movable iron piece 13 is separated from the opposing piece 3d of the yoke 3 and the distance of the gap portion is large, the suction force F becomes large because the gap portion area S3 is large. When the movable iron piece 13 is attracted and the movable iron piece side suction portion 15 of the movable iron piece 13 is close to the opposing piece 3d, and the distance of the gap portion is reduced, the gap portion area S4 becomes smaller and the suction force F Is big.

Therefore, even if the movable iron piece 13 is separated from the opposing piece 3d of the yoke 3, or if the movable iron piece 13 is close to the opposing piece 3d of the yoke 3, the attraction force F is large, and the electric circuit can be reliably and quickly performed. Can be shut off.

[0043]

Since the breaker tripping device of the present invention is constructed as described above, in the first aspect of the present invention, the distance between the movable iron piece and the tip of the side surface of the yoke is small. In other words, since the suction part where the gap area through which the magnetic flux passes becomes smaller, the gap part area is large when the distance between the suction part and the movable iron piece is large, so the suction force is large, while the suction part and the movable part are movable. When the distance from the iron piece is short, the gap area is small, and therefore the suction force is large, so that a breaker that has a sufficient suction force regardless of the distance between the suction part and the movable iron piece and reliably shuts off the electric circuit. The present invention has an effect that a trip device can be provided.

According to the second aspect of the present invention, the suction portion extends from the front end of the side surface of the yoke at a predetermined angle in the direction of the other side surface and the bottom surface. When the distance from the movable iron piece is large, the gap area is large, and thus the suction force is large. On the other hand, when the distance between the suction part and the movable iron piece is small, the gap area is small and, therefore, the suction force is large. This has the effect of providing a breaker trip device that has a sufficient suction force irrespective of the distance between the suction unit and the movable iron piece, and reliably shuts off the electric circuit.

According to the third aspect of the present invention, the suction portion is provided at a predetermined angle substantially parallel to the movable iron piece when the movable iron piece is most separated from the yoke. It is the maximum when it is opened most, and it is possible to provide a breaker tripping device having a larger suction force.

According to the fourth aspect of the present invention, since the movable iron piece is provided with the movable iron piece side suction portion in which the smaller the distance to the opposing piece, the smaller the area of the gap through which the magnetic flux passes, the movable iron piece is provided. When the distance from the movable iron side suction unit is large, the gap area is large, and therefore the suction force is large,
On the other hand, when the distance between the opposing piece and the movable iron piece side suction unit is small, the gap area is small, and therefore the suction force is large,
Therefore, there is an effect that it is possible to provide a breaker tripping device that has a sufficient suction force regardless of the distance between the opposing piece and the movable iron piece side suction section and reliably shuts off the electric circuit.

According to the fifth aspect of the present invention, when the movable iron piece is closed by the yoke, the movable iron piece side suction portion has a predetermined angle with respect to the opposing piece. When the distance from the movable part is large, the gap area is large, and therefore the suction force is large. On the other hand, when the distance between the opposing piece and the movable iron piece side suction part is small, the gap area is small, and the suction force is large. Therefore, it is possible to provide a breaker tripping device that has a sufficient suction force regardless of the distance between the opposing piece and the movable iron piece side suction section and that reliably shuts off the electric circuit.

According to the sixth aspect of the present invention, the movable iron piece side suction portion is provided at a predetermined angle which is substantially parallel to the opposing piece when the movable iron piece is most separated from the yoke. The gap area is maximized when the movable iron piece is separated most, which provides an effect that a breaker tripping device having a larger suction force can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view of a breaker trip device of the present invention.

FIG. 2 is a cross-sectional view of the breaker trip device in a state where a movable iron piece is opened.

FIG. 3 is a sectional view showing a state in which a movable iron piece of a breaker trip device is closed.

FIG. 4 is a perspective view of the breaker tripping device of the present invention.

FIG. 5 is a cross-sectional view of the breaker trip device in a state where a movable iron piece is opened.

FIG. 6 is a sectional view showing a state in which a movable iron piece of a breaker trip device is closed.

FIG. 7 is a sectional view of a tripping device for a breaker;

FIG. 8 is a cross-sectional view of a yoke as an example of the related art.

FIG. 9 is a cross-sectional view of another conventional yoke.

FIG. 10 is a sectional view of another conventional yoke.

FIG. 11 is an explanatory diagram showing a relationship between a suction force of a yoke and a distance of a gap portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric circuit 3 Yoke 3a Bottom part 3b Side part 3c Side part 3d Opposing piece 13 Movable iron piece 14 Suction part 15 Movable iron one side suction part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshihiro Oido 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd.

Claims (6)

[Claims] An electric circuit, a U-shaped yoke extending from both ends of the bottom surface and the bottom surface and having side surfaces facing each other and surrounding the electric circuit by the bottom surface and the side surface, and a tip of the side surface of the yoke And a movable iron piece that is attracted to the yoke that is excited when an overcurrent flows through the electric circuit and that is interrupted by the movable iron piece, thereby cutting off the electric circuit. A breaker tripping device, characterized in that a suction unit is provided in which the smaller the size of the gap, the smaller the area of the gap through which the magnetic flux passes. 2. The breaker trip device according to claim 1, wherein the suction portion extends from the tip of the side portion of the yoke at a predetermined angle in the direction of the other side portion and the bottom portion. 3. The tripping device for a breaker according to claim 2, wherein the suction portion is provided at a predetermined angle substantially parallel to the movable iron piece when the movable iron piece is most separated from the yoke. 4. A U-shaped yoke extending from both ends of the bottom surface and the bottom surface and facing each other, the U-shaped yoke having the bottom surface and the side surface surrounding the electric circuit, and a tip of the side surface of the yoke. And a movable iron piece that is attracted to the yoke that is excited when an overcurrent flows through the electric circuit and that cuts off the electric circuit. An opposing piece extending in the direction of the other side face is provided on the movable iron piece, and the movable iron piece has a movable iron piece side suction portion in which the smaller the distance to the opposing piece, the smaller the gap area through which the magnetic flux passes. Breaker trip device. 5. The tripping device for a breaker according to claim 4, wherein the movable iron piece side suction portion has a predetermined angle with respect to the facing piece when the movable iron piece is closed by the yoke. 6. The breaker according to claim 5, wherein said movable iron piece side suction portion is provided at a predetermined angle which is substantially parallel to the opposing piece when the movable iron piece is most separated from the yoke. Trip device.