JPH076601Y2 - Circuit and disconnector tripping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a trip device for a circuit breaker or a circuit breaker equipped with a thermal bimetal.

[Conventional technology]

FIG. 3 is a side sectional view showing a conventional tripping device for a circuit breaker and a circuit breaker, FIG. 4 is a sectional view taken along line IV-IV in FIG. 3, and FIG.
It is a perspective view of the operation iron piece part of the figure. 3 to 5, (1) is a base formed of an insulating material, (2) is a cover formed of an insulating material, (3) is a conductive strip, and a fixed contact (4) is provided at one end. A terminal screw (5) for wire connection is attached to the other end. A movable contact (6) has a movable contact (7) which is fixed to and separated from the fixed contact (4) at one end and has a recess (8) of the operating handle (8) at the other end.
supported by a). (9) is a bimetal that is heated by passing current and is curved in the direction of arrow (A), (1)
Reference numeral 0) is a magnetic pole piece which is biased by a current flowing through the bimetal (9), and is an intermediate side (10a) fixed to the bimetal (9) by spot welding and both end sides (10b) connected to both sides thereof. , (10b). Reference numeral (11) is an operating iron piece whose lower end is bent so as to surround the tip of the bimetal (9), and is rotatably supported by its shaft portion (111). (11a) is an operating iron piece (11)
A square hole provided almost in the center of the engaging surface (11
b) is formed. The engaging portion of the trip rod (12) is adapted to engage with the engaging surface (11b). A flexible conductor (13) electrically connects the free end of the bimetal (9) and the movable contactor (6). (14) is an expansion spring for operation, one end of which is locked to the center of the movable contact (6) and the other end of which is locked to the center of the trip rod (12). Reference numeral (15) is a conductive strip, one end of which is fixed to the bimetal (9) and the other end of which is attached with a terminal screw (16) for connecting an electric wire.
Reference numeral (17) is an adjusting screw for changing the amount of engagement between the trip bar (12) and the engaging surface (11b) of the operating iron piece (11) by pressing the conductive strip (15).

The conventional trip device for circuit breakers and circuit breakers is constructed as described above, and when the electric circuit is overloaded, the bimetal (9)
Bends in the direction of the arrow (A) and rotates the operating iron piece (11) counterclockwise about the shaft portion (111). By this rotation, the engagement between the tip end of the trip rod (12) and the engagement surface (11b) of the operating iron piece (11) is released, and the circuit breaker and the circuit breaker are tripped.

Also, when a particularly large current flows due to a short circuit accident in the electric circuit, the electromagnetic action of the current flowing through the bimetal (9) causes a fourth gap between the pole piece (10) and the operating iron piece (11). Magnetic flux is generated as shown by the dotted line in the figure, and in order to attract the operating iron piece (11) to the magnetic pole piece (10) side, the operating iron piece (11) is rotated counterclockwise about the shaft (111),
In the same manner as described above, the circuit and the breaker are tripped. In addition,
In this case, the bimetal (9) is curved at the same time,
Before this, the circuit or the breaker is tripped earlier by this electromagnetic action, and this tripping element is usually called an instantaneous trip element.

[Problems to be solved by the invention]

In the conventional trip device as described above, if the interval shown in FIG. 4 (a) is narrowed, the magnetic flux generated between the pole piece (10) and the operating iron piece (11) is increased, and the tripping by electromagnetic action occurs. The operation can be performed with a slightly lower current, and the smoothing and breaking effect at the time of tripping can be improved smoothly, but the interval of (a) in FIG. 4 is Since it is a moving space for the operating iron piece (11), it cannot be narrowed,
Now, there is a problem that the tripping operation cannot be performed due to electromagnetic action at a slightly lower current.

The present invention has been made in order to solve such a problem, and it is a tripping device for a circuit or a circuit breaker, which can achieve smoothing, breaking, and high breaking effect by making an electromagnetic action at a lower current. The purpose is to provide.

[Means for solving problems]

A trip device for a circuit breaker and a circuit breaker according to the present invention attaches a magnetic pole piece to a bimetal so that the magnetic pole piece is biased in a direction away from the bimetal so that there is a space between the intermediate piece of the magnetic pole piece and the bimetal. A spring is provided.

[Action]

In this invention, the electromagnetic action of the current flowing through the bimetal causes the magnetic pole pieces to be attracted to the side of the operating iron piece against the spring so that the mutual spacing is narrowed to start the operation of the operating iron piece, and the resistance to the operation of the operating iron piece When the static friction changes to the dynamic friction and decreases, the operating iron piece is operated by the restoring force of the spring and the suction force of both.

〔Example〕

FIG. 1 is a side view of a trip device portion according to an embodiment of the present invention,
FIG. 2 is a sectional view taken along the line II-II in FIG. In FIGS. 1 and 2, (10A) is a letter-shaped pole piece, (18)
Is fixed to the bimetal (9) at one end and the pole piece (10
A leaf spring fixed to the inner surface of the intermediate side (10a) of (A) supports the magnetic pole piece (10A) so that it can elastically move toward the operating iron piece (11). It should be noted that, except for the above, it is exactly the same as the conventional device.

In the trip device for a circuit breaker and a circuit breaker configured as described above, the operation caused by the electromagnetic action of the current flowing through the bimetal (9) is first shown in FIG. Magnetic flux is generated as shown by the dotted line inside,
An attractive force is generated between the pole piece (10A) and the operating iron piece (11). At this time, since the operating iron piece (11) has a large resistance to operation, first the magnetic pole piece (10A) is resisted against the leaf spring (18) to the second position.
As shown in the figure (b), move to the operating iron piece (11) side. Therefore, the pole piece (10A) is first moved in accordance with the current flowing through the bimetal (9), and as a result, the gap between the two is larger than that shown in FIG. ), It becomes narrower as shown in (b), and a larger suction force is generated. When the current value exceeds a certain value, the attraction force becomes larger than the resistance of the operating iron piece (11) and the operating iron piece (11)
Works. The resistance to the operation of the operating iron piece (11) is the resistance generated by static friction until the operation starts,
Once the operation is started, static friction changes to dynamic friction, and in general dynamic friction has a smaller value than static friction.
When 1) starts operating, the restoring force of the leaf spring (18), which was elastically deformed by the movement of the magnetic pole piece (10A) until then, is between the magnetic pole piece (10A) and the operating iron piece (11). The actuating iron piece (11) is actuated by the suction force of (1), and the trip rod (12) is tripped from its engaging portion (11b) to activate the circuit and the circuit breaker.

Therefore, as compared with the conventional one, when the tripping operation caused by the electromagnetic action is started, the distance between the magnetic pole piece (10A) and the operating iron piece (11) is as described above (a) to (b). Since it becomes small, it operates at a smaller current value.

[Effect of device]

As described above, the present invention has a simple structure in which the magnetic pole piece is attached to the bimetal so as to be elastically movable in the direction of the actuating iron piece. It has the effect of smoothing and improving the cutting effect.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a trip device portion according to an embodiment of the present invention,
FIG. 2 is a sectional view taken along the line II-II in FIG. 1, in which (a) shows an initial state, (b) shows a state in the middle of operation, and (c) shows a completed state. FIG. 3 is a side sectional view showing a circuit breaker and a circuit breaker by a conventional trip device, FIG. 4 is a sectional view taken along line IV-IV in FIG. 3, and FIG. 5 is a perspective view of an operating iron piece portion in FIG. It is a figure. In the figure, (9) is a bimetal, (10A) is a pole piece,
(10a) is the middle side, (10b) is the end side, (11) is the operating iron piece,
(12) is a trip rod, and (18) is a leaf spring. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Scope of utility model registration request] 1. An operating iron piece which is rotatably supported and whose trip bar is locked so as to be disengaged by the rotation, and the operating iron piece which is provided in parallel with the operating iron piece and is heated by a passing current. A bimetal that rotates the operating iron piece when curved in the same direction as the rotation, a character-shaped intermediate side is located on the curved side of the bimetal, and both shape-shaped end sides are on both sides of the bimetal. Character-shaped magnetic pole pieces facing each other at a predetermined distance from the operating iron piece, and the magnetic pole pieces are biased in a direction away from the bimetal so that a space is provided between the intermediate side of the magnetic pole piece and the bimetal. A trip device for a circuit breaker or a circuit breaker, comprising: a spring for attaching the magnetic pole piece to the bimetal in a closed state. 2. A circuit as claimed in claim 1, wherein the spring is a leaf spring, one end of which is fixed to a bimetal and the other end of which is fixed to the inner surface of the middle side of the pole piece. Trip device.