JP4928307B2 - Circuit breaker - Google Patents

Description

The present invention relates to a circuit breaker, and more particularly to a tripping device in a thermal-electromagnetic circuit breaker.

A conventional tripping device for a circuit breaker includes a tripping device for a circuit breaker as shown in FIG. The circuit breaker is a circuit breaker having an opening / closing mechanism that interlocks the ON / OFF operation of the operation handle with the opening / closing operation of the contact and opens the contact by the operation of a thermal-electromagnetic tripping device. is there. The opening / closing mechanism is provided with a latch mechanism portion that is tripped by the operation of the tripping device. Normally, the latch mechanism is a tripping mechanism in which a part of an arm member provided with a spring member for biasing the contactor to an ON position or an OFF position is driven to be pulled by an operation of the tripping device. It latches on the latch part provided in a member, and it is provided so that the latch of the latch part of the said trip member and a part of said arm member may be released at the time of trip. The tripping device is a thermal-electromagnetic type comprising a bimetal device that performs long-time tripping, and an electromagnetic tripping device that includes an electromagnetic element such as a fixed iron core and a movable iron piece that performs instantaneous tripping. Tripping device.

When an overcurrent such as an overload current or a short-circuit current flows through the electric circuit to which the circuit breaker is connected, in an area where the circuit breaker is overloaded with respect to the rated current, the Joule heat due to the overload current causes When the bimetal is overheated and curved in a predetermined direction, the bimetal device acts on the opening / closing mechanism, and the long-time tripping by the bimetal device is performed by pulling off the latch mechanism. Further, in a region where a short circuit occurs with respect to the rated current of the circuit breaker, the movable iron piece is attracted to the fixed iron core by the electromagnetic force generated by the short circuit current, thereby acting on the opening / closing mechanism and the latch The mechanism is tripped and instantaneous tripping is performed using an electromagnetic tripping device.

The tripping device 105 in the circuit breaker shown in FIG. 8 is held rotatably so as to constitute a latch part of an electromagnetic frame 1054 that is a fixed iron core, an electromagnetic iron piece 1053 that is a movable iron piece, and an opening / closing mechanism part. The tripping member 1051 is included.

The electromagnetic frame 1054 is provided so as to constitute a magnetic circuit with the electromagnetic iron piece 1053, and a bimetal 1055 as a conductor is disposed so as to penetrate the magnetic circuit. The electromagnetic frame 1054 substantially omits the bimetal 1055. It is formed to surround.

The electromagnetic iron piece 1053 is fixed to the tripping member 1051 by screwing and operates integrally with the tripping member 1051. That is, when the electromagnetic iron piece is attracted to the electromagnetic frame by an electromagnetic force generated by the short-circuit current in a region where the short circuit with respect to the rated current of the circuit breaker is operated, the tripping is performed together with the electromagnetic iron piece. The member 1051 is also integrated so as to start rotating in the direction in which the electromagnetic iron piece is attracted to the electromagnetic frame.

The trip member 1051 is provided with a trip portion 1052 and a trip action portion for tripping the latch portion by the action of the latch portion 1052 and the bimetal on one side from the rotating shaft 10512 portion, and the trip member 1051 on the other side. There is provided a biasing spring engaging portion that engages with a biasing spring (not shown) for biasing the tripping member 1051 in a direction to keep the latching portion 1052 latched, that is, in a direction to widen the gap of the magnetic circuit. Normally, when the circuit breaker is in an ON state, the latch of the latch unit 1052 is maintained.

JP-A-2005-353440 FIG.

Recently, as a function of a circuit breaker incorporated in a distribution board, it is desired to have a function of protecting a relatively small short circuit (cord short circuit) that occurs on the load side of the outlet circuit. However, the conventional tripping device has the following problems.

In the region of a comparatively small short circuit (cord short circuit) as described above, the electromagnetic force generated by the short circuit current is smaller than the normal short circuit current. Therefore, the force (attraction force) by which the electromagnetic iron pieces are attracted to the electromagnetic frame is weak, and the electromagnetic tripping device may not be driven sufficiently.

If the electromagnetic trip device is not driven sufficiently, the latch portion of the trip member cannot be removed, the contact cannot be separated, and the electric circuit cannot be interrupted.

As a condition for tripping the latch portion of the tripping member, the suction force needs to be larger than the force that prevents the latch portion of the opening / closing mechanism from being tripped. That is, there are two forces that prevent the latch part from being tripped: a force for releasing the latch of the latch part (engagement force) and a force for biasing the tripping member by the biasing spring (biasing force). For this reason, it is necessary that the attractive force be larger than the resultant force at the position where the electromagnetic trip device acts on the trip member.

For example, as a solution for reducing the magnitude of the short-circuit current at which the tripping device starts to be driven so that the tripping operation can be performed in a relatively small short-circuit (cord short-circuit) region, the biasing spring is applied. In order to overcome the resultant force of the force and the engagement force, in order to increase the magnetic flux penetrating the magnetic circuit, it is necessary to increase the cross-sectional area of the magnetic circuit, that is, the thickness of the members used for the electromagnetic frame and the movable iron piece. As a result, the tripping device may be increased in size, which in turn may increase the size of the circuit breaker body. Therefore, the thickness of the members used for the electromagnetic frame and the movable iron piece is increased. It was not realistic to respond.

In order to solve such problems, the present invention provides a circuit breaker that can reliably operate even in a relatively small short-circuit (cord short-circuit) region without increasing the size of the circuit breaker body. It is for the purpose.

In order to solve the above-described problems, in the first aspect of the invention, the ON / OFF operation of the operation handle is interlocked with the opening / closing operation of the contact, and the contact is made by the operation of the thermal-electromagnetic trip device. In the circuit breaker having an opening / closing mechanism for separating the child, the latch mechanism portion provided in the opening / closing mechanism to be tripped by the operation of the tripping device is configured such that the latch mechanism portion is moved by the electromagnetic tripping device. A circuit breaker is provided that is biased in a latching direction.

As a result, the latch mechanism portion is biased in the direction in which the latch mechanism portion is latched by the electromagnetic trip device. When the drive starts, the biasing force of the latch mechanism in the latching direction is released, and then the movable iron piece is attracted to the fixed iron core to release the latch. That is, the electromagnetic tripping device is a first stage for releasing the biasing direction of the latch mechanism in the latching direction, and an electromagnetic tripping device acts on the latch mechanism to release the latch. The stage has a step-like role during driving, so that the movable iron piece has a free running distance, reduces the tripping load, and latches even with electromagnetic force generated by a relatively small current. Since it is configured so that the force when acting on the mechanism is sufficient, the drive start current of the electromagnetic trip device can be reduced, and it is a small but relatively small short (cord short) region It is possible to provide a circuit breaker that can reliably operate.

Further, the latch mechanism and the electromagnetic trip device are rotatably held by a body constituting a circuit breaker,
The electromagnetic trip device provides a circuit breaker characterized in that it is biased by an elastic member in a direction in which the latch mechanism is latched.

As a result, the latch mechanism and the electromagnetic trip device can be urged in a direction in which the latch mechanism is latched by a single elastic body, thereby reducing the number of parts and improving productivity. It can be carried out.

In addition, the latch mechanism and the electromagnetic tripping device are provided in the body constituting the circuit breaker.
The circuit breaker may be configured by holding the rotation centers of the latch mechanism and the electromagnetic trip device substantially the same.

Accordingly, by making the respective rotation centers of the latch mechanism portion and the electromagnetic tripping device substantially coincide with each other, the attractive force can be effectively utilized and the tripping operation can be performed efficiently.

According to the present invention, it is possible to provide a circuit breaker that can reliably operate even in a relatively small short circuit (cord short circuit) region without increasing the size of the circuit breaker body.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the internal structure of the circuit breaker when the power terminal side is the left side. In FIG. 1, an L phase is arranged on the front side and an N phase (not shown) is arranged on the far side.

The circuit breaker is composed of a case 100 and a cover 200. A cover is provided for each of the L phase and the N phase, and FIG. 1 shows a state in which the L phase side cover is removed.

The body is provided with a power supply terminal 101 and a load terminal 102, and a movable contact 1031 provided with a movable contact 1031a is paired with the movable contact 1031a in an energizing path from the power supply terminal 101 to the load terminal 102. An opening / closing mechanism 104 including a contact device 103 including a fixed contact 1032 having a fixed contact 1032a facing to each other, a handle member 1041 for opening or closing the contact device 103, and an overload in an electric circuit. When an electric current is generated, an electromagnetic tripping device comprising a thermal tripping device a105a using a bimetal device that acts on the switching mechanism 104 to open the movable contact 1031a and a movable iron piece 1053 fixed iron core 1054. A tripping device 105 composed of the device b105b is provided.

The opening / closing mechanism 104 is provided with a latch mechanism portion that is tripped by the operation of the tripping device 105. The latch mechanism is normally driven by a part of the arm member 1043 provided with a spring member for biasing the movable contact 1031 to the ON position or OFF position by the operation of the trip device. The tripping member 1051 is latched by a latch portion, and at the time of tripping, the latch portion of the tripping member and a part of the arm member 1043 are unlatched.

A handle member 1041 is rotatably supported via a pin 1042 in the case 100. The handle member 1041 has an arm portion 1041a extending downward in the figure, and a movable contact latch provided at one end thereof. The movable contact 1031 is rotatably supported by the portion 1041b.

In addition, an arm 1043 is rotatably supported on the case 100 via a pin 1044, and a tripping member 1051 is also rotatably supported via a pin 1056. The trip member 1051 is provided with a latch portion 1052 for engaging a part of the arm 1043. When the arm 1043 is engaged with the trip member 1051, the contact device 103 is operated by operating the handle member. The opening operation and the closing operation are configured to be possible.

The arm 1043 and the movable contact 1031 are provided with spring member latching portions 1045a and 1045b, and a spring member 1045 made of a tension spring is hooked and biased so that they are attracted to each other. In the handle member 1041 and the movable contact 1031 constituting the link at 1041b, the line connecting the spring member locking portion 1045b of the movable contact 1031 and the pin 1042 which is the rotation center of the handle member 1041 is a dead line, and the ON state At this time, the movable contact locking portion 1041b is disposed so as to cross the dead line to the load terminal side in the drawing. In FIG. 1, the movable contactor 1031 maintains the illustrated posture in the ON state. The handle member 1041 is provided with a handle rotation angle restricting portion 1041c that comes into contact with the case 100 so as to define the upper limit of the rotation angle.

The handle member 1041 and the movable contact 1031 form a link by the 1041b. In FIG. 1, the movable contact 1031 receives a rotational force counterclockwise by the restoring force of the spring member 1045, and the handle member 1041 receives a rotational force counterclockwise. The movable contact 1031 is kept in the ON state (closed state) so as to receive a rotational force in the clockwise direction and press against the fixed contact 1032. Next, the case where it is made to operate from this state to an open state is demonstrated.

In FIG. 1, when the handle member 1041 is rotated to the right (clockwise), the arm 1041a is rotated to the left (clockwise) using the pin 1042 as a rotation screw, and the handle member 1041, the movable contact 1031, When the movable contact locking part 1041b crosses the dead line of the link composed of the above, the action of the spring member 1045 on the movable contact 1031 is reversed, and the movable contact 1031 rotates the movable contact locking part 1041b at the center of rotation. As shown in FIG. 2, the counter contact 1032 is urged in the counterclockwise direction to open the contact (FIG. 2 OFF state).

Next, a case where the tripping device 105 is activated due to an overcurrent flowing through the electric circuit will be described. First, in an area where the circuit breaker is overloaded with respect to the rated current, the bimetal device 1055 constituting a part of the electric circuit provided in the case 100 in FIG. Deflection in the direction away from the tripping member 1051 with the middle and upper end as a fulcrum, is engaged with an adjustment screw 10515 for adjusting the operating time provided in the tripping member 1051, and the tripping member 1051 rotates the pin 1056 As a center, the arm 1043 rotates in a direction in which the latch amount in the latch portion 1052 decreases.

The bimetal 1055 arranged so that the high expansion side of the material becomes the movable iron piece 1053 side is gradually bent toward the electromagnetic frame 1054 due to the bending characteristics of the bimetal 1055 due to heat, and comes into contact with the tip of the adjustment screw 10515 of the tripping member 1051. .

The bimetal 1055 in contact with the tip of the adjusting screw 10515 is further curved, and the tripping member 1051 starts to rotate with the pressing force in contact with the movable iron piece 1053. As the tripping member 1051 rotates, the engagement amount of the latch portion 1052 gradually decreases. Finally, the engagement is disengaged, the balance of the link of the opening / closing mechanism portion is lost, and the contact device 103 is opened. To do.

FIG. 7 shows that the tripping member 1051 is rotated together with the movable iron piece 1053 by the pressing force due to the bending of the bimetal 1055, and the arm 105 that keeps the closed state of the circuit breaker and the tripping member 1051 is pulled. Indicates the state at the moment of removal.

When the rotation proceeds and the latch is released, the arm 1043 rotates counterclockwise in FIG. 2 with the pin 1044 as the center of rotation.

Accordingly, the spring member locking portion 1045a also rotates counterclockwise, and when the spring member locking portion 1045b crosses the line connecting the spring member locking portion 1045b and the movable contact locking portion 1041b, the spring member for the movable contact 1031 The action of 1045 is reversed, and the movable contact 1031 receives a force in the counterclockwise direction with the movable contact locking portion 1045b as the center of rotation in the drawing, and performs the opening operation, that is, the trip operation from the fixed contact 1032 ( Fig. 3 Trip state).

Next, in order to re-engage the arm 1043, which has been unlatched by the trip operation, and the tripping member 1051, that is, to perform a reset operation, the handle member 1041 is once rotated clockwise (OFF direction) in FIG. Then, the arm 1041a of the handle member 1041 is pressed by the operating force against the protrusion 1043a provided in the vicinity of the pin 1044 that is the rotation center of the arm 1043, whereby the arm is rotated counterclockwise in FIG. Is rotated as a pin 1044, and the engaging portion of the arm 1043 is raised to the position of the latch portion 1052 of the tripping member to engage with each other.

Next, the electromagnetic trip device 105b that operates in a region where a short circuit occurs with respect to the rated current of the circuit breaker will be described in detail with reference to FIG.

An electromagnetic trip device 105b is provided in the vicinity of a tripping member 1051 that is configured to be rotatable on a rotating shaft 1056 provided at one end and that constitutes a latch portion, and in the vicinity of a bimetal 1055 that is a conductor. In this case, a movable iron piece 1053 acting on the tripping member 1051 by electromagnetic force and an electromagnetic frame 1054 having a movable iron piece adsorbing portion 10541 for sucking and adsorbing the movable iron piece 1053 are configured. The dismounting member 1051 is disposed so as to be rotatable about the rotation axis.

An engaging portion 1053 that acts on the tripping member 1051 is provided at the tip of the movable iron piece 1053.

The trip member 1051 is first provided with a portion in which a latch portion 1052 is formed from the rotation shaft 1056 so that the movable iron piece 1053 is brought into contact with the electromagnetic frame 1054 and the contact portion is provided on the extension. A formed portion is provided. In addition, the tripping member 1051 is elastic to act to urge the tripping member 1051 in a direction that hinders the tripping operation by the tripping device, that is, the direction opposite to the direction in which the movable iron piece 1053 is attracted to the electromagnetic frame 1054. A tripping member spring 10514 formed of a member is provided.

The tripping member spring 10514 is formed of a winding spring, one end is held by a holding portion provided in the case, and the other end is hung on the movable iron piece 1053. The tripping member spring 10514 acts on the movable iron piece 1053 so as to urge the movable iron piece 1053 in the direction of the tripping member 1051 with the tripping member turning shaft as a turning center.

The electromagnetic frame 1054 and the movable iron piece 1053 are arranged so as to surround the conductor bimetal 1055. When a short-circuit current is generated, the movable iron piece 1053 is attracted to the fixed iron core 1054 by the electromagnetic force generated by the current flowing through the bimetal. By being driven, the tripping member 1051 rotates about the rotation shaft 1056.

In a normal state, the movable iron piece 1053 is urged in a direction in which a gap is provided in a magnetic circuit composed of the movable iron piece 1053 and the electromagnetic frame 1054 by the urging force of the tripping member spring 10514. The tripping member 1051 is urged by the movable iron piece 1053 in a direction in which the tripping member 1051 is engaged with the opening / closing mechanism by a latch. That is, the tripping member spring 10514 is provided so as to urge the movable iron piece 1053 clockwise in the figure, and to urge the tripping member 1051 clockwise in the figure via the movable iron piece 1053. .

When a short-circuit current flows through the bimetal 1055, an attractive force acts between the movable iron piece 1053 and the electromagnetic frame 1054 by a magnetic circuit formed by the electromagnetic frame 1054 and the movable iron piece 1053 due to the electromagnetic force generated by the current flowing through the bimetal. First, the movable iron piece 1053 starts rotating in the direction of the electromagnetic frame 1054 around the rotation axis of the tripping member 1051 against the urging force of the tripping member spring 10514.

At this time, the movable iron piece 1053 rotates so that one end of the tripping member spring 10514 hung on the movable iron piece 1053 is also compressed. Since the other end of the tripping member spring 10514 is held by the holding portion of the case, when the movable iron piece 1053 starts to rotate, the attraction force due to the electromagnetic force is the moment by the tripping member spring. It is only necessary to obtain a size that can overcome the above. That is, since the movable iron piece 1053 does not have a structure that is integrally attached to the tripping member as in the prior art, the electromagnetic force required at the initial stage of suction can be small. Further, since the tripping member 1051 has a structure that is biased in the latching direction via the movable iron piece 1053, when the movable iron piece 1053 is sucked, a force that biases the tripping member 1051 in the latching direction. Will disappear.

Next, FIG. 5 shows a state at the moment when the rotation of the movable iron piece 1053 advances and the tip of the movable iron piece 1053 comes into contact with the contact portion of the tripping member 1051.

From this stage, the tripping member 1051 starts to rotate with the movable iron piece 1053 in contact therewith. As the tripping member 1051 rotates, the engagement amount of the latch portion 1052 gradually decreases. Finally, the engagement is disengaged, the balance of the link of the opening / closing mechanism portion is lost, and the contact device 103 is opened. To do.

FIG. 6 shows a state at the moment when the tripping member 1051 rotated together with the movable iron piece 1053 trips the latch portion 1052 with the arm. The movable iron piece 1053 is finally attracted to the movable iron piece adsorbing portion 10541 of the electromagnetic frame 1054 after releasing the engagement of the latch portion 1052. When the contact device 103 is opened, the current flowing through the conductor disappears and the electromagnetic force disappears. The movable iron piece 1053 is again biased by the force of the tripping member spring 10514 in the direction in which the air gap in the magnetic circuit increases. The movable iron piece 1053 abuts on the tripping member 1051, and the tripping member 1051 is also urged in the same direction to be in a trip position.

Now, in the operation of the tripping device described above, it has been explained that the tripping member spring does not act on the tripping member while the movable iron piece is attracted to the electromagnetic frame and rotates. In the conventional tripping device, since the movable iron piece is integrated with the tripping member by screwing or the like, the movable iron piece and the tripping member do not have an initial gap (free running distance), and the tripping member is made of the movable iron piece. In addition, since the impact force (impact force) was not expected, and the tripping member spring load and engagement force were applied to the movable iron piece, the magnitude of the short-circuit current at which the movable iron piece started to drive was large. When trying to reduce the magnitude of the short-circuit current that starts driving, the cross-sectional area of the magnetic circuit, that is, the electromagnetic frame and the movable frame, is increased in order to increase the magnetic flux that penetrates the magnetic circuit so as to overcome the biasing force and engagement force of the tripping member spring. It was necessary to increase the thickness of the member used for the iron piece, which could increase the size of the tripping device.

In the present invention, the latch mechanism is urged in the direction in which the latch mechanism is latched by the electromagnetic trip device. When the release device starts driving, the biasing force of the latch mechanism in the latching direction is released, and then the movable iron piece is acted upon by being attracted to the fixed iron core, thereby releasing the latch. That is, the electromagnetic tripping device is a first stage for releasing the biasing direction of the latch mechanism in the latching direction, and an electromagnetic tripping device acts on the latch mechanism to release the latch. The stage has a step-like role during driving, so that the movable iron piece has a free running distance, reduces the tripping load, and latches even with electromagnetic force generated by a relatively small current. Since it is configured so that the force when acting on the mechanism is sufficient, the drive start current of the electromagnetic trip device can be reduced, and it is a small but relatively small short (cord short) region It is possible to provide a circuit breaker that can reliably operate.

In the tripping device of the present invention, the number of parts can be reduced, and further, the tripping member spring 10514 can be prevented from acting on the tripping member 1051 during driving, so that the tripping member 1051 is tripped. Since the force only needs to have a magnitude corresponding to the component force in the trip direction of the engagement force in the latch unit 1052, the magnitude of the short-circuit current for starting driving in the trip device 103 can be further reduced. That is, it is added that there is a secondary effect that it is possible to provide the tripping device 103 capable of improving the protection capability of the electric circuit by reducing the magnitude of the short-circuit current that can be tripped.

The present invention can be applied to a circuit breaker capable of performing a reliable breaking operation even in a relatively small short-circuit (cord protection) region without increasing the size of the vessel. In addition, since it is not necessary to use parts having complicated shapes, it is effective for automation in assembling circuit breakers, and further improvement in productivity can be desired.

The internal structure figure of the circuit breaker of this invention. (ON state) The internal structure figure of the circuit breaker of this invention. (OFF state) The internal structure figure of the circuit breaker of this invention. (TRIP state) FIG. 1 shows the operation of the trip device. FIG. 2 shows the operation of the trip device. FIG. 3 shows the operation of the tripping device. FIG. 4 shows the operation of the tripping device. The example of the structure of the conventional instantaneous tripping device of a circuit breaker is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit breaker 100 Cover 101 Power supply side terminal 102 Load side terminal 103 Contact device 1031a Movable contact 1031 Movable contact 1032a Fixed contact 1032 Fixed contact 104 Opening / closing mechanism part 1041 Handle member 1041a Handle leg part 1041b Movable contact latching part 1041c Handle rotation angle restricting portion 1042 Handle pin 1043 Arm member 1043a Protruding portion 1044 Arm pin 1045 Spring member 1045a Spring member locking portion 1045b Spring member locking portion 105 Tripping device 1051 Tripping member 10512 Turning shaft 10513 Contacting portion 10514 Tripping Member spring 10515 Adjustment screw 1052 Latch part 1053 Electromagnetic iron piece 1054 Electromagnetic frame 10541 Movable iron piece adsorbing part 1055 Bimetal 1056 Tripping member pin

Claims (3)

The operation handle ON / OFF operation is linked to the opening / closing operation of the contact,
In a circuit breaker having an opening / closing mechanism for opening a contact by operation of a thermal-electromagnetic trip device,
A latch mechanism portion provided in the opening / closing mechanism to be tripped by the operation of the tripping device,
The circuit breaker, wherein the electromagnetic trip device biases the latch mechanism in a latching direction.
The latch mechanism and the electromagnetic trip device are rotatably held by a body constituting a circuit breaker,
2. The circuit breaker according to claim 1, wherein the electromagnetic trip device is biased by an elastic member in a direction in which the latch mechanism is latched.
The latch mechanism and the electromagnetic tripping device are provided in the body constituting the circuit breaker.
3. The circuit breaker according to claim 2, wherein the center of rotation of each of the latch mechanism and the electromagnetic trip device is held substantially the same.

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