JP2022049446A - Overcurrent switch and circuit breaker with overcurrent switch - Google Patents

Abstract

To provide an overcurrent switch that can save time and labor for assembly adjustment.SOLUTION: An overcurrent switch 14 includes that opens a contact via an opening/closing mechanism 7 when contacts 3 and 4 are placed in a current path to detect a current in the current path and an overcurrent flows includes a heater 10 connected to the flow path, and a temperature-sensitive operation mechanism component 5 heated by the heater. The temperature-sensitive operation mechanism component has a built-in temperature-sensitive ferrite 19 manufactured by controlling the Curie temperature, and the temperature-sensitive ferrite changes to a non-magnetic material when the temperature reaches the Curie temperature due to the heat generated by the heater due to the overcurrent of the current path, and the temperature-sensitive operation mechanism component transmits the mechanical operation to the opening/closing mechanism to open the contact.SELECTED DRAWING: Figure 3

Description

The present invention relates to an overcurrent switch and a circuit breaker including the overcurrent switch.

Circuit breakers such as circuit breakers for wiring and leakage breakers are equipped with an opening / closing mechanism that opens and closes contacts placed in the current path by turning the operation handle on and off, and overcurrent (overcurrent) in the current path. When a short-circuit current or instantaneous operating current flows through the temperature-sensitive operating mechanism that interlocks the opening / closing mechanism so that the contact is open when (overload current) flows, the contact It has an overcurrent switch by magnetic force that interlocks the opening / closing mechanism so that it is in the open state.

As an overcurrent switch, for example, a switch incorporated in a circuit breaker of Patent Documents 1 and 2 is known.
For example, the circuit breaker of Patent Document 1 is provided with a thermal-electromagnetic temperature-sensitive operation mechanism, and when an overload current flows in the current path, the bimetal is curved by Joule heat generated by the overload current. The trip lever rotates to open the opening / closing mechanism (long-term operation). Further, when a short-circuit current or an instantaneous operating current flows in the current path, the armature of the electromagnet instantly moves to the fixed iron core side and the trip lever rotates to open the opening / closing mechanism (instantaneous operation).

Further, for example, the completely electromagnetic temperature-sensitive operation mechanism portion in the circuit breaker of Patent Document 2 is sealed with a fixed iron core in which a movable iron core, braking oil, and a braking spring are sealed in a non-magnetic pipe-shaped pot. An oil dash pot is used. When the overload current flows, the movable core overcomes the braking spring and approaches the fixed core, the electromagnetic force of the electromagnet increases, the armature linked to the trip lever is attracted to the fixed core, and the trip lever rotates. To open the opening / closing mechanism (long-term operation). Further, when a short-circuit current flows, the electromagnetic force of the electromagnet is further increased, so that the armature is instantly attracted to the fixed iron core, and the trip lever is instantaneously rotated to open the opening / closing mechanism (instantaneous operation).

Japanese Unexamined Patent Publication No. 2008-210742 Japanese Unexamined Patent Publication No. 2010-176906

However, in the thermal-electromagnetic temperature sensitive operation mechanism unit shown in Patent Document 1, the operating temperature of the bimetal in the long-time operation is easily affected by the disturbance temperature depending on the variation of the bimetal and the mounting state, and the operating temperature is adjusted. The problem is that it takes time and effort.
Further, in the oil dashpot of the completely electromagnetic overcurrent switch shown in Patent Document 2, it is necessary to carefully design the material, material size and assembly accuracy in order to set the operating temperature and correct the assembly accuracy. Therefore, the oil dash pot of the temperature-sensitive operation mechanism must be assembled inside the circuit breaker with high accuracy, and there is a problem that adjustment requires time and labor.
Therefore, the present invention has been made to solve the above-mentioned conventional problems, and provides an overcurrent switch capable of reducing time and labor for assembly adjustment and a circuit breaker provided with the overcurrent switch. To do.

In order to achieve the above object, in the overcurrent switch according to one aspect of the present invention, a contact is arranged in the current path, and when the current in the current path is detected and the overcurrent flows, the overcurrent switch is passed through the opening / closing mechanism unit. It is an overcurrent switch that opens the contact, and includes a heater connected to the current path and a temperature-sensitive operating mechanism component that is heated by the heater, and the temperature-sensitive operating mechanism component controls the curie temperature. The temperature-sensitive ferrite manufactured is built-in, and the temperature-sensitive ferrite changes to a non-magnetic material when it reaches the Curie temperature due to the heat generated by the heater due to the flow of overcurrent in the current path, and the temperature-sensitive operation mechanism parts become The mechanical operation is transmitted to the opening / closing mechanism unit to open the contact.
Further, the circuit breaker according to one aspect of the present invention includes the above-mentioned overcurrent switch.

According to the overcurrent switch according to the present invention and the circuit breaker provided with the overcurrent switch, it is possible to reduce the time and labor for manufacturing assembly adjustment.

It is sectional drawing of the 1-pole part which shows the circuit breaker provided with the overcurrent switch of 1st Embodiment which concerns on this invention. It is a perspective view of the triode product of the circuit breaker provided with the overcurrent switch of 1st Embodiment which concerns on this invention. It is a figure which shows that the rated current flows through the coil-shaped heater of the overcurrent switch of 1st Embodiment, and the temperature sensitive operation mechanism component is in an initial state. It is a figure which shows that any one of the overload current, the short-term operation current, and the instantaneous operation current flows through the coil-shaped heater of the overcurrent switch of 1st Embodiment, and the temperature sensitive operation mechanism component is in an operating state. It is a figure which shows the overcurrent switch of 1st Embodiment provided with the temperature sensitive operation mechanism component which can adjust the time extension time. It is a figure which shows that the rated current flows through the coil-shaped heater of the overcurrent switch of 2nd Embodiment, and the temperature sensitive operation mechanism component is in an initial state. It is a figure which shows that any of the overload current, the short-term operation current, and the instantaneous operation current flows through the coil-shaped heater of the overcurrent switch of the 2nd Embodiment, and the temperature sensitive operation mechanism component is in an operating state. It is a figure which shows the initial state of the temperature sensitive operation mechanism component of 3rd Embodiment in which a heater has a flat plate shape. It is a figure which shows that the temperature sensitive operation mechanism component of 3rd Embodiment is in an operating state.

Next, an embodiment according to the present invention will be described with reference to the drawings. In the description of the drawings below, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the plane dimensions, the ratio of the thickness of each layer, etc. are different from the actual ones. Therefore, the specific thickness and dimensions should be determined in consideration of the following explanation. In addition, it goes without saying that parts having different dimensional relationships and ratios are included between the drawings.

Further, the embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention describes the material, shape, structure, and arrangement of constituent parts. Etc. are not specified as the following. The technical idea of the present invention may be modified in various ways within the technical scope specified by the claims described in the claims.

[First Embodiment]
First, the first embodiment according to the present invention will be described with reference to FIGS. 1 to 4.
FIG. 1 shows a cross-sectional view of a circuit breaker 1, in which a fixed contact 3, a movable contact 4, an arc extinguishing device (not shown), and a temperature-sensitive operation mechanism component 5 are contained in a unit case 2 made of a molded resin. , A trip mechanism unit 6 and an opening / closing mechanism unit 7. Further, FIG. 2 is a perspective view of the circuit breaker 1 having a three-pole cross-sectional structure of FIG.
As shown in FIG. 1, the fixed contact 3 is connected to a power supply side terminal 8 and has a fixed contact 3a on one side surface.
The load-side terminal 11 is connected to one end of a coil-shaped heater 10 arranged on the outer periphery of the cylindrical case 16 of the temperature-sensitive operation mechanism component 5, which will be described later, and the other end of the coil-shaped heater 10 is load-side conductive. It is connected to the member 9. The load-side conductive member 9 is connected to the movable contact 4 by a conduction wire (not shown). The movable contact 4 includes a movable contact 4a that contacts the fixed contact 3a.

The opening / closing mechanism 7 opens the movable contact 4a of the movable contact 4 from the fixed contact 3a of the fixed contact 3 or causes the movable contact 4a to close the fixed contact 3a. The opening / closing mechanism 7 closes the movable contact 4a of the movable contact 4 to the fixed contact 3a of the fixed contact 3 when the handle 12 is in the on position of the solid line position in FIG. 1, and causes the power supply side terminal 8 and the load to be closed. Energize between the side terminal 11 and the side terminal 11. Further, when the opening / closing mechanism 7 moves the handle 12 from the on position to the off position indicated by the two-dot chain line, the movable contact 4a of the movable contact 4 is opened from the fixed contact 3a of the fixed contact 3 to open the pole, and the power supply is supplied. The side terminal 8 and the load side terminal 11 are de-energized. Further, when the trip operation is transmitted from the trip mechanism unit 6, the opening / closing mechanism unit 7 opens the movable contact 4a of the movable contact 4 from the fixed contact 3a of the fixed contact 3 to open the pole with the power supply side terminal 8 and the load. The space between the side terminal 11 and the side terminal 11 is de-energized.

The trip mechanism unit 6 transmits the trip operation to the opening / closing mechanism unit 7 when the plunger operation transmission component 13 operates due to the swing of the temperature-sensitive operation mechanism component 5. The overcurrent switch 14 according to the present invention is composed of the temperature-sensitive operation mechanism component 5, the trip mechanism unit 6, the coil-shaped heater 10, and the plunger operation transmission component 13.

As shown in FIG. 3, the temperature-sensitive operation mechanism component 5 includes a magnet fixing base 17, a permanent magnet 18, a temperature-sensitive ferrite 19, a plunger 20, and a coil spring 21 arranged inside the cylindrical case 16.
The cylindrical case 16 has an opening formed at one end in the longitudinal direction and a through hole 16b through which the plunger 20 passes at the other end in the longitudinal direction.
The magnet fixing base 17 is fixed to the opening at one end of the cylindrical case 16 in the longitudinal direction together with the magnet fixing base 17 and the permanent magnet 18 by magnetic adsorption or adhesion, and is fixed to one end side inside the cylindrical case 16. ..

The temperature-sensitive ferrite 19 is arranged adjacent to the permanent magnet 18 so as to be movable in the longitudinal direction inside the cylindrical case 16. The temperature-sensitive ferritic 19 is a soft magnetic material when the temperature is lower than the Curie temperature, and is a ferrite-based magnetic material having a property of changing to a non-magnetic material when heated above the Curie temperature.
The Curie temperature of the temperature-sensitive ferrite 19 is such that when an overload current (for example, 200% A or more of the rated current) flows through the coiled heater 10 and heat is generated, the temperature-sensitive ferrite 19 is a temperature-sensitive operation mechanism component due to heat conduction. It is set to the temperature of the temperature-sensitive ferrite 19 when 5 operates.

The plunger 20 is fixed to the temperature-sensitive ferrite 19 and is movably arranged inside the cylindrical case 16 in the longitudinal direction.
The coil spring 21 is contracted by being magnetically attracted by the permanent magnet 18 when the temperature-sensitive ferrite 19 is in a soft magnetic state.
When the temperature-sensitive ferrite 19 receives heat from the coil-shaped heater 10 and becomes a non-magnetic state, the coil spring 21 is not affected by the magnetic attraction by the permanent magnet 18 and is in a stretched state.
The plunger operation transmission component 13 has a fulcrum 13a, and transmits the expansion and contraction of the coil spring 21 due to the soft magnetic state and the non-magnetic state of the temperature-sensitive ferrite 19 to the trip mechanism portion 6.

Next, the operation of the overcurrent switch 14 and the circuit breaker 1 of the present embodiment will be described with reference to FIGS. 1 to 4.
In the circuit breaker 1, the opening / closing mechanism portion 7 closes the movable contact 4a of the movable contact 4 and the fixed contact 3a of the fixed contact 3 with the handle 12 in the on position (solid line position in FIG. 1), and the power supply side terminal operates. It is assumed that the rated current flows through the energization path between the 8 and the load side terminal 11 to make the energization state.

At this time, the temperature-sensitive ferrite 19 of the temperature-sensitive operation mechanism component 5 is a soft magnetic material because a temperature lower than the Curie temperature is thermally conducted from the coil-shaped heater 10 through which the rated current is flowing. Therefore, in the initial state of the temperature-sensitive operation mechanism component 5, as shown in FIG. 3, the temperature-sensitive ferrite 19 in the state of a soft magnetic material is magnetically attracted by the permanent magnet 18. The plunger 20 fixed to the temperature-sensitive ferrite 19 does not rotate the plunger operation transmission component 13, and does not transmit the force of the coil spring 21 to the trip mechanism portion 6 via the plunger operation transmission component 13.

When an overload current (long-term operating current) flows in the energizing path between the power supply side terminal 8 and the load side terminal 11, a temperature higher than the Curie temperature is thermally conducted from the coiled heater 10, so that the temperature-sensitive ferrite 19 is used. Changes with a non-magnetic material. Due to the heat capacity of all the components of the temperature-sensitive operation mechanism component 5, the temperature-sensitive ferrite 19 has a time delay until it reaches the Curie temperature. This time extension time is the same as the long-time operation, and an overload current (long-time operation current) flows in the energization path, and the long-time operation time can be set by setting the heat capacity of the temperature-sensitive operation mechanism component 5.

The plunger 20 is moved in a direction away from the permanent magnet 18 by the stretching force of the coil spring 21 whose magnetic adsorption with the permanent magnet 18 is released by the temperature-sensitive ferrite 19 changed to a non-magnetic material. Swing of the operating mechanism component 5). At the same time, since the plunger 20 rotates the plunger motion transmission component 13 around the fulcrum 13a, the swing motion of the temperature sensitive motion mechanism component 5 is transmitted to the trip mechanism unit 6.

In the trip mechanism portion 6, the swing of the temperature-sensitive operation mechanism component 5 is transmitted via the plunger operation transmission component 13, so that the movable contact 4a of the movable contact 4 of the opening / closing mechanism portion 7 is fixed to the fixed contact of the contact 3. Open pole operation is performed from 3a (long-term operation). As a result, the circuit breaker 1 is in a trip state in which the power supply side terminal 8 and the load side terminal 11 are in a non-energized state.
When a short-circuit current (short-circuit operating current, instantaneous operating current) flows in the energizing path between the power supply side terminal 8 and the load side terminal 11, fast operation cannot be expected in the operation by heat conduction. 5 operates using a magnetic field generated from the coiled heater 10. A large magnetic field is generated by the short-circuit current and the coiled heater 10, and the temperature-sensitive ferrite 19 which is a soft magnetic material performs magnetic inversion.

Since the magnetic attraction of the temperature-sensitive ferrite 19 that is magnetically inverted is reduced with respect to the permanent magnet 18, the elongating force of the coil spring 21 acts to move the temperature-sensitive ferrite 19 in a direction away from the permanent magnet 18. At the same time, since the plunger 20 rotates the plunger motion transmission component 13 around the fulcrum 13a, the swing motion of the temperature sensitive motion mechanism component 5 is transmitted to the trip mechanism unit 6.
The trip mechanism unit 6 opens the movable contact 4a of the movable contact 4 of the opening / closing mechanism 7 from the fixed contact 3a of the fixed contact 3 by transmitting the operation (short-term operating current, instantaneous operation). As a result, the circuit breaker 1 is in a trip state in which the power supply side terminal 8 and the load side terminal 11 are in a non-energized state.

Next, the action and effect of this embodiment will be described.
The temperature-sensitive ferrite 19 incorporated in the temperature-sensitive operating mechanism component 5 of the present embodiment can be manufactured with an accuracy of 1 ° C. ± 3 ° C. with a resolution of -10 to 130 ° C. It is easier to set the operating temperature compared to the bimetal operating temperature used in the current switch. Even in the time setting for long-term operation, the bimetal product had heat conduction leakage to other parts, but the temperature-sensitive operation mechanism component 5 has less heat conduction leakage and depends on the heat capacity of the entire component. It is also easy to set the delay time for long-term operation.

Further, since the overcurrent switch 14 of the present embodiment does not need to be assembled with high precision unlike the electromagnet with an oil dashpot used in the conventional completely electromagnetic overcurrent switch, the assembly adjustment of the circuit breaker 1 is performed. It is possible to reduce time and labor.
Further, the time extension time of the temperature-sensitive operation mechanism component 5 of the present embodiment changes the heat capacity by changing the calorific value of the coil-shaped heater 10 and the thickness and size of the cylindrical case 16 and the magnet fixing base 17. You can adjust it freely just by yourself.

What is shown in FIG. 5 shows a first embodiment in which the time extension time of the temperature sensitive operation mechanism component 5 shown in FIGS. 3 and 4 can be adjusted.
In FIG. 5, the outer circumference of the temperature-sensitive operation mechanism component 5 on the upper side is covered with a tubular heat capacity adjusting cap 23.
A cap support portion 24 provided inside the unit case 2 is arranged above the temperature-sensitive operation mechanism component 5. The adjusting screw B is screwed into the cap support portion 24, and the lower end of the adjusting screw B is fixed to the top portion 23a of the heat capacity adjusting cap 23.
When the screwing amount of the adjusting screw B is changed, the heat capacity of the temperature-sensitive operation mechanism component 5 is increased or decreased by the heat capacity adjusting cap 23, and the heat transfer coefficient from the coiled heater 10 to the temperature-sensitive ferrite 19 is changed. It is possible to adjust the time of a certain long-time operation.
It should be noted that the operation is possible even if the vertical positions of the temperature-sensitive ferrite 19 and the permanent magnet 18 of the first embodiment are exchanged.

[Second Embodiment]
Next, FIGS. 6 and 7 show the overcurrent switch 51 of the second embodiment.
The overcurrent switch 51 of the second embodiment includes a temperature-sensitive operation mechanism component 53, a trip mechanism unit 6, a coil-shaped heater 54, and a plunger operation transmission component 13.
The temperature-sensitive operation mechanism component 53 includes a columnar case 62 made of a magnetic material, a magnet fixing member 56, a permanent magnet 57, a magnetic yoke 58, a temperature-sensitive ferrite 59, a plunger 60, and a coil spring 61. A coil-shaped heater 54 is wound around and arranged around the coil.
The columnar case 62 is made of a magnetic material having both ends open in the longitudinal direction, and a through hole 63b is formed in the center thereof.

The magnet fixing member 56 is made of a magnetic material, and is fixed by closing the opening at the other end together with the permanent magnet 57, the columnar case 62, and the magnetic yoke 58.
The plunger 60 includes a plunger contact 60a that is fixed to the temperature-sensitive ferrite 59, is movably arranged inside the temperature-sensitive operation mechanism component 53 in the longitudinal direction, and is inserted through the through hole 63b.
The coil spring 61 applies a pressing force to the temperature-sensitive ferrite 59 in a direction away from the permanent magnet 57.

Next, the operation of the circuit breaker 1 provided with the overcurrent switch 51 of the present embodiment will be described.
The temperature-sensitive ferrite 59 of the temperature-sensitive operation mechanism component 53 is connected to the coil-shaped heater 54 through which the rated current is flowing when the rated current is flowing in the energizing path between the power supply side terminal 8 and the load side terminal 11. Since the temperature below the Curie temperature is thermally conducted, it is a soft magnetic material, and it is located at the position shown in FIG. 6 by the magnetic force from the permanent magnet 57 via the columnar case 62 and the magnetic force from the permanent magnet 57 via the magnetic yoke 58. This is the state when the rated current is energized in which the temperature-sensitive ferrite 59 is located.

When the rated current of the temperature-sensitive operation mechanism component 53 is energized, the plunger 60 is housed inside the columnar case 62.
As a result, in the initial state of the temperature-sensitive operation mechanism component 53, the position is maintained by the magnetic field M passing through the permanent magnet 57, the magnet fixing member 56, the columnar case 62, the temperature-sensitive ferrite 59, and the magnetic yoke 58.
Here, when an overload current flows in the energization path between the power supply side terminal 8 and the load side terminal 11, the heat generated by the coiled heater 54 is transferred to the temperature sensitive ferrite 59 via the temperature sensitive operation mechanism component 53. The temperature-sensitive ferrite 59 is transferred and heated to the Curie temperature for a predetermined time extension time to change into a non-magnetic material.

As shown in FIG. 7, in the temperature-sensitive operation mechanism component 53, the temperature-sensitive ferrite 59 changed to a non-magnetic material loses magnetic adsorption, and the stretching force of the coil spring 61 acts to separate it from the magnetic field M due to the permanent magnet 57. Move in the direction of the magnet. At the same time, the plunger 60 moves together with the temperature-sensitive ferrite 59, and the plunger contact 60a passes through the through hole 63b and protrudes to the outside.

The temperature-sensitive operation mechanism component 53 mechanically operates due to the overload current flowing through the coil-shaped heater 54, and the plunger operation transmission component 13 rotates around the fulcrum 13a to operate the trip mechanism portion 6 to open and close. The mechanism unit 7 opens the movable contact 4a of the movable contact 4 from the fixed contact 3a of the fixed contact 3 (long-term operation).

When a short-circuit current (short-circuit operating current, instantaneous operating current) flows in the energizing path between the power supply side terminal 8 and the load side terminal 11, fast operation cannot be expected in the operation by heat conduction, so the temperature-sensitive operation mechanism The component 53 operates using a magnetic field generated from the coiled heater 10. A large magnetic field is generated by the short-circuit current and the coiled heater 10, and the cylindrical case 62 and the magnetic yoke 58 are in a magnetically saturated state.

Since the magnetic yoke 58 is in a magnetically saturated state, the magnetic field M cannot be maintained, the attraction is reduced, and the stretching force of the coil spring 21 acts to move in a direction away from the permanent magnet 57, and at the same time, the plunger 60 moves. , The plunger operation transmission component 13 rotates around the fulcrum 13a to transmit a force to the trip mechanism unit 6. The temperature-sensitive ferrite 59 is also magnetized in a direction away from the magnetic field M by the magnetic field generated from the coiled heater 10.
The trip mechanism unit 6 opens the movable contact 4a of the movable contact 4 of the opening / closing mechanism 7 from the fixed contact 3a of the fixed contact 3 by transmitting the operation (short-term operating current, instantaneous operation). As a result, the circuit breaker 1 is in a trip state in which the power supply side terminal 8 and the load side terminal 11 are in a non-energized state.

In the overcurrent switch 51 of the second embodiment, a short-circuit current (short-circuit operating current, instantaneous operating current) flows through the coiled heater 54, and an induced magnetic field generated around the coiled heater 54 is a temperature-sensitive operating mechanism. Since the instantaneous tripping operation is performed by cutting off the magnetic field M magnetically attracted in the initial state of the component 53, it is possible to simplify the device configuration of the instantaneous tripping operation.
The time extension time of the overcurrent switch 51 of the second embodiment is determined by the calorific value of the coiled heater 54 and the calorific value of the coiled heater 54.
It can be freely adjusted only by changing the thickness and size of the magnet fixing member 56 and the columnar case 62 to change the heat capacity.
Further, the operating sensitivity of the instantaneous tripping operation can be easily adjusted by using a magnetic material or a non-magnetic material for the columnar case 62, the volume of the magnetic yoke 58, the temperature-sensitive ferrite 59 and the plunger 60.
[Third Embodiment]

Next, what is shown in FIGS. 8 and 9 shows the temperature-sensitive operation mechanism component 25 of the third embodiment using the flat plate heater 27. In the temperature-sensitive operation mechanism component 25 of the present embodiment, the flat plate-shaped case heat transfer portion 28 extends outward from the cylindrical case 16 of the temperature-sensitive operation mechanism component 5 of the first embodiment, but the temperature is sensitive. The other internal structure of the operation mechanism component 25 is the same structure as the temperature-sensitive operation mechanism component 5 of the first embodiment. The internal structure of the temperature-sensitive operation mechanism component 25 may be the same as that of the temperature-sensitive operation mechanism component 53 of the second embodiment.

The flat plate heater 27 is connected to a flat surface contact portion 27a to which the case heat transfer portion 28 is surface-contacted and fixed, a first connection portion 27b connected to the load-side conductive member 9, and a load-side terminal 11. The second connection portion 27c and the like are provided.
The temperature-sensitive operation mechanism component 25 of the present embodiment uses the flat plate heater 27 to perform only long-term operation, and adjusts the time of long-term operation by adjusting the calorific value of the flat plate heater 27. Is possible. In addition, in order to add short-term operation and instantaneous operation, a structure called an armature, which is mounted on a conventional overcurrent switch, required for short-term operation and instantaneous operation is required.

The temperature-sensitive operation mechanism component 25 of the present embodiment can be used in place of the bimetal of a thermal-electromagnetic overcurrent switch (for example, Japanese Patent Application Laid-Open No. 2008-210742) using a conventional bimetal. That is, the flat plate heater 27 of the temperature-sensitive operation mechanism component 25 of the present embodiment is arranged between the current paths, and in the conventional device, the plunger 20 (plunger contact 20b) is replaced with the bimetal linked to the trip lever. Place in close proximity to. Then, when an overload current flows in the current path, the plunger 20 rotates the trip lever to perform long-time operation, and when a short-circuit current flows in the current path, the armature of the electromagnet is used as in the conventional device. The trip lever may be instantaneously moved to the fixed iron core side and the trip lever may be rotated to perform the instantaneous pulling operation.

1 Circuit breaker 2 Unit case 3 Fixed contact 3a Fixed contact 4 Movable contact 4a Movable contact 5 Temperature-sensitive operation mechanism parts 6 Trip mechanism 7 Opening and closing mechanism 8 Power supply side terminal 9 Load side conductive member 10 Coil-shaped heater 11 Load side terminal 12 Handle 13 Plunger operation transmission component 13a Support point 14 Overcurrent switch 16 Cylindrical case 16b Through hole 17 Magnet fixing base 18 Permanent magnet 19 Temperature sensitive ferrite 20 Plunger 20b Plunger contact 21 Coil spring 23 Thermal capacity adjustment cap 23a Thermal capacity adjustment Cap top 24 Cap support 25 Temperature-sensitive operation mechanism parts 27 Flat heater 27a Surface contact part 27b First connection part 27c Second connection part 28 Case heat transfer part 51 Overcurrent switch 51 Overcurrent switch 53 Temperature-sensitive operation mechanism parts 54 Coil-shaped heater 56 Magnet fixing member 57 Permanent magnet 58 Magnetic yoke 59 Temperature-sensitive ferrite 60 Plunger 60a Plunger contact 61 Coil spring 62 Cylindrical case 63b Through hole M Magnetic field

Claims (6)

An overcurrent switch in which a contact is arranged in a current path, and when an overcurrent flows by detecting the current in the current path, the contact is opened via an opening / closing mechanism.
A heater connected to the current path and a temperature-sensitive operation mechanism component heated by the heater are provided.
The temperature-sensitive operation mechanism component has a built-in temperature-sensitive ferrite manufactured by controlling the Curie temperature, and the temperature-sensitive ferrite reaches the Curie temperature due to heat generation of the heater due to an overcurrent in the current path. An overcurrent switch that changes to a non-magnetic material, and the temperature-sensitive operation mechanism component transmits a mechanical operation to the opening / closing mechanism portion to open the contact. The heater is a coil-shaped heater arranged on the outer periphery of the temperature-sensitive operation mechanism component.
In the temperature-sensitive operation mechanism component, the temperature-sensitive ferrite changes to a non-magnetic material due to the heat generated by the coiled heater due to the overload current of the current path, and the long-time operation is transmitted to the opening / closing mechanism portion. An induced magnetic field generated in the coil-shaped heater due to a short-circuit current in the current path or an instantaneous operating current acts inside the temperature-sensitive operating mechanism component to enter a magnetically saturated state, so that instantaneous operation is performed in the opening / closing mechanism portion. The overcurrent switch according to claim 1, wherein the overcurrent switch is transmitted. The temperature-sensitive operation mechanism component adjusts the heat capacity of the component containing the temperature-sensitive ferrite and the heat conduction time until the Curie temperature is reached by the coiled heater that reaches the temperature-sensitive ferrite. The overcurrent switch according to claim 2, wherein the time of the long-time operation can be adjusted. The temperature-sensitive operation mechanism component includes a permanent magnet, a plunger, a temperature-sensitive ferrite that is arranged between the permanent magnet and the plunger and is magnetically attracted to the permanent magnet as a magnetic material, and the temperature-sensitive ferrite. An elastic member pressing in the moving direction of the plunger and is arranged.
When an overcurrent flows through the heater and the temperature-sensitive ferrite changes to a non-magnetic material, the plunger fixed to the temperature-sensitive ferrite moves by pressing the elastic member to perform a long-time operation. The overcurrent switch according to claim 1, wherein the overcurrent switch is transmitted to a unit. The temperature-sensitive operation mechanism component is arranged in series in the order of a permanent magnet, a magnetic yoke, the temperature-sensitive ferrite, and a plunger, and an elastic member pressing in the moving direction of the plunger is arranged in the case. And
When an overcurrent flows through the coiled heater and the temperature-sensitive ferrite changes to a non-magnetic material, the plunger fixed to the temperature-sensitive ferrite moves by pressing the elastic member to perform long-term operation. While transmitting to the opening / closing mechanism,
A short-circuit current or an instantaneous operating current flows through the coil-shaped heater, an induced magnetic field is generated in the coil-shaped heater, and a magnetic saturation state is established between the permanent magnet and the temperature-sensitive ferrite, so that the plunger is moved. The overcurrent switch according to claim 2 or 3, wherein the overcurrent switch is moved by pressing the elastic member to transmit an instantaneous operation to the opening / closing mechanism portion. A circuit breaker comprising the overcurrent switch according to any one of claims 1 to 5.

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