JP5808038B2 - Circuit breaker with abnormal overheat detection structure - Google Patents

Description

The present invention detects abnormal overheating of a terminal to which a circuit breaker and an electric wire are connected, and prevents abnormality of the terminal that prevents the circuit breaker from being burnt out and spreading to construction materials and peripheral devices around the circuit breaker. The present invention relates to a circuit breaker having an overheat detection structure.

As is well known, the circuit breaker is interposed in the electric circuit, and when an accident current such as an overcurrent, a short circuit current, or a leakage current in the electric circuit is detected and a predetermined operating condition is met, the electric circuit is electrically connected. It shuts off and operates to cut off the power supply to the load side.

The circuit breaker is provided with a connection terminal that allows repeated electrical connection with an external circuit. In a circuit breaker that is installed on a distribution board such as a distribution board for a house or a control panel and is connected to a power line of an external circuit drawn into the panel, the power line and the circuit are installed at the construction site where the distribution board is installed. The terminal on the power supply side of the circuit breaker is connected. At this time, the connection between the power supply line and the connection terminal on the power supply side of the circuit breaker is inadequate, or regular maintenance (such as terminal tightening confirmation) is incomplete and used for a long time. If continued, abnormal overheating may occur in the terminal portion.

As a cause of abnormal overheating of the terminal to which the electric wire is connected in the circuit breaker, there is an increase in contact resistance between the electric wire and the terminal due to forgetting to tighten the terminal screw or loosening of the terminal screw due to long-term use. In addition, it may be assumed that the contact surface between the power source line and the connection terminal of the circuit breaker is oxidized, heat is generated due to the increase in contact resistance due to the creep of the electric wire or the presence of foreign matter.

Also, the reason for abnormal overheating of the parts other than the connection part between the power line and the connection terminal part is due to internal resistance due to wear and drop of contacts in the circuit breaker, oxidization, and the presence of foreign matter with ageing. Heat generation due to the increase can be assumed.

If such an abnormal overheating condition continues, the components that make up the circuit breaker will burn out, and the circuit breaker itself will burn out. There is concern about the spread of fire to peripherals and peripheral equipment.

However, ordinary circuit breakers do not have a function to detect these abnormal overheating, and measures are taken to check connection during construction and to perform periodic maintenance inspections to prevent abnormal overheating. It was. Although these preventive measures are effective in preventing abnormal overheating, abnormal overheating may continue until the next maintenance inspection in terms of suppressing abnormal overheating once generated. Concerns about the occurrence of burnout accidents and fire spreads associated with general use have not been completely eliminated.

Therefore, a circuit with an overheat prevention device having a function of detecting these abnormal overheats and shutting off the power supply to the load side and preventing a burnout accident due to the abnormal overheat when the abnormal overheat occurs. A circuit breaker is disclosed. (Patent Document 1, Patent Document 2)

In patent document 1, the following is disclosed as what detects abnormal overheating. Bimetal plates 25 and 26 for overheat detection are fixed to the power supply side terminal and the load side terminal of the circuit breaker, and a transmission plate that is displaced following the displacement of the bimetal plate is suspended between the two bimetal plates. In addition, the operation rod that is normally locked to the transmission plate is moved by tripping the circuit breaker by releasing the locking relationship with the transmission plate due to the displacement of the transmission plate when overheated. It is to be prepared. In addition, when the engagement relationship between the transmission plate and the actuating rod is released and the actuating rod is operated, the operation rod is projected outside the circuit breaker to display the operation and press the actuating rod. Thus, an overheat prevention device that enables resetting of the circuit breaker is added to a general circuit breaker.

In patent document 2, it was made in view of the mechanical structure in the above-mentioned patent document 1, and abnormal overheating is detected electrically, and it is interrupted by an electrical signal output when the abnormal overheating is detected. What drives a tripping device that opens the contact of the container is disclosed.

Specifically, the mechanical operation disclosed in Patent Document 1 is made in view of the fact that it cannot be applied unless the internal mechanism of the circuit breaker is changed. In addition, the circuit breaker in the power supply system can be centrally managed, and can be used for overheating protection of other devices such as an electromagnetic switch provided in the same circuit.

As a configuration for detecting abnormal overheating, a temperature-sensitive element whose electrical output changes corresponding to the temperature of the wire connection terminal, and detecting the abnormal overheating by comparing the electrical output of the temperature-sensitive element with a normal level And a determination circuit.

Examples of the temperature sensing element include a thermistor, a thermocouple using a thermoelectromotive force, an infrared sensor for detecting radiant heat, and the temperature sensing element is arranged near the terminal of the mold case as an arrangement form of the temperature sensing element. The temperature sensor unit is configured to be embedded and disposed on a resin-molded insulating support independent of the mold case, and the temperature sensor unit is integrated using the mounting groove of the interelectrode barrier. A form attached to the mold case, a form in which the temperature sensor unit is formed in a plate shape so that it can be mounted between the back surface of the mold case and the board surface, a terminal used to insulate the circuit breaker terminal part The temperature sensor is embedded in an insulator, such as a ceramic with high thermal conductivity, attached to the cover, inserted into a hole provided in the insulation support of the temperature sensor unit, and long by a spring. Resiliently held so as to be movable in a direction, such as in the form of contacting the distal end of the insulator is disclosed breaker terminals.

Japanese Utility Model Publication No. 56-25156 JP 62-8419 A

As disclosed in Patent Document 1 and Patent Document 2, it is possible to add a function for detecting abnormal overheating to a normal circuit breaker. However, in Patent Document 1, in order to add a function for detecting abnormal overheating, it is necessary to separately provide a space for arranging a mechanical mechanism for detecting abnormal overheating on the entire back surface side of the circuit breaker. In addition, the circuit breaker is greatly modified, such as the external shape of the circuit breaker changes significantly. In addition, in Patent Document 2, it is necessary to separately provide a unit including a temperature sensor such as a temperature sensing element and a determination circuit and to attach the unit to a circuit breaker when arranging an electrical device. Because there are many parts, and it is necessary to introduce it as a temperature measurement system, it is complicated to add functions.

In any case, it functions as a single function for detecting abnormal overheating. Considering the recent trend of circuit breakers, it is possible to maintain or improve the electrical safety performance while saving the space of the circuit breaker, that is, maintain the current breaker performance while reducing the external size of the circuit breaker. Although improvement is required, there is a problem that it is not realistic to add a function of detecting abnormal overheating related to electrical safety in addition to these to constitute a circuit breaker.

Therefore, the present invention has been made in view of the above problems, and by performing a simple modification in a normal circuit breaker, a function of detecting abnormal overheating that the circuit breaker does not have can be easily added. An object of the present invention is to provide an abnormal overheat detection structure for a circuit breaker that can improve the current interruption performance that the circuit breaker originally has.

An abnormal overheat detection structure of a circuit breaker according to the present invention is configured to solve the above-described problem, and a fixed contact that turns on and off a power circuit on a power source side and an electric circuit on a load side inside the container body. And an opening / closing mechanism for driving the movable contact to open and close, and detecting an abnormal current flowing in the electric circuit to act on the latch of the opening / closing mechanism to cause the opening / closing mechanism to be tripped. A trip device for opening the contact and an arc space from which arc gas generated when the contact is driven to open by the action of the trip device are provided. A circuit breaker provided by exposing a connection terminal portion connected to the electric circuit inside the container body and connected to an external power supply conductor, wherein a bimetal for overheating detection for detecting overheating in the connection terminal portion, Configure the connection terminals The conductor is fixed to the inner side of the container and exposed to the arc space in the vicinity of the contact, and is engaged with the bimetal for overheating detection and interlocks when the bimetal is bent, It is preferable to provide an abnormal overheat detection structure for a circuit breaker characterized by providing an interlocking member that acts on the latch.

According to such a configuration, the bimetal for overheat detection is fixed to the inside of the body of the conductor constituting the connection terminal portion and disposed in the arc space originally provided in the circuit breaker, and the overheat detection is performed. Since the interlocking member that engages and interlocks with the bimetal is also disposed inside the container body, a function of detecting overheating can be added without changing the outer shape of the circuit breaker body. In addition, since the overheating detection bimetal is disposed so as to be exposed to the arc space in the vicinity of the contact, the arc gas generated in the arc space is cooled by the overheating detection bimetal, and the interruption capability can be improved.

The overheat detection bimetal may be configured by providing a plurality of holes through which arc gas permeates on a surface facing the movable contact.

According to such a configuration, the contact area between the arc gas generated in the arc space and the bimetal for overheating detection is increased, the cooling efficiency is improved, the arc gas can be easily escaped from the arc space, and the interruption capability is further improved. Can be improved.

The overheat detection bimetal may be configured by forming a yoke from the bimetal toward the movable contact.

According to such a configuration, the arc generated between the fixed contact and the movable contact can be efficiently drawn toward the overmetal detection bimetal by the yoke. That is, by providing the bimetal for detecting overheating also serving as the arc extinguishing device, the generated arc is extended and the arc voltage is increased, so that the arc can be easily extinguished and the interruption capability can be improved.

The arc space is provided with an arc extinguishing device that is pivotally supported by rotating the bimetal for detecting overheating, and is engaged with the arc extinguishing device so that the latch of the opening / closing mechanism portion is engaged. An abnormal overheat detection structure for a circuit breaker may be provided by providing an interlocking member that acts.

According to such a configuration, it is possible to add a part of the function of detecting abnormal overheating by using an arc extinguishing device that quickly extinguishes the arc generated in the arc space. A function to detect overheating without changing can be added. Moreover, since the arc extinguishing device is used, it is possible to add a function of detecting abnormal overheating while maintaining the interruption capability.

The arc extinguishing device is provided with a grid that divides the arc, and an arc extinguishing wall that supports the grid,
The arc extinguishing device may be configured by integrally forming the arc extinguishing device and the bimetal by supporting the overheating detection bimetal on an arc extinguishing wall.

According to such a configuration, since the arc extinguishing device and the bimetal are integrally formed, there is no need to support the arc extinguishing device, and a function of detecting abnormal overheating can be added with a simpler configuration.

The overheat detection bimetal is fixed so as to substantially surround the fixed contact in the vicinity of the fixed contact of the fixed contact, and a part of the overheat detection bimetal is engaged with the interlocking member. An abnormal overheating structure of the circuit breaker may be provided.

According to such a configuration, the bimetal for detecting overheating can be used as a traveling plate for arc generated in the arc space and a cooling plate for arc gas, and in addition to the structure using the yoke, the consumption of contacts can be suppressed. it can. The yoke may be formed integrally with the overheat detecting bimetal so as to have a function as an arc traveling plate and a function as a yoke. Further, a separate member may be fixed to a part of the bimetal for detecting overheating, and the separate plate may be engaged with the interlocking plate. By using a separate member, the workability of the bimetal for detecting overheat is improved, and by forming the separate member with a heat-resistant member such as ceramic, corrosion resistance and insulation against arc gas can be improved.

As described above, according to the present invention, it is possible to easily add a function of detecting abnormal overheating that the circuit breaker does not have by performing a simple modification in a normal circuit breaker, and the circuit breaker is inherently It is possible to provide an abnormal overheat detection structure for a circuit breaker that can improve the current interrupting performance.

The block diagram of the abnormal overheat detection structure of the circuit breaker which shows 1st embodiment of this invention is shown. The principal part enlarged view in 1st embodiment is shown. The principal part enlarged view in 2nd embodiment is shown. The principal part enlarged view in 3rd embodiment is shown. The principal part enlarged view in 4th embodiment is shown. The figure which shows the operation | movement in 4th embodiment is shown. The figure which shows the modification in 5th embodiment is shown. The principal part enlarged view in 6th embodiment is shown. The structure which detects the abnormal overheating of the terminal part in a prior art example is shown.

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

(First embodiment)
FIG. 1 shows an internal configuration diagram of a circuit breaker 100 according to the present embodiment. First, the basic structure of the circuit breaker 100 according to the present embodiment will be described.

The circuit breaker 100 is configured such that the outer shell is covered with vessel bodies 101 and 102 each made of a molded case. The container body 101 is a base to which components in the circuit breaker are attached and fixed, and the container body 102 is a cover that covers the main components by covering the base body. A terminal portion connected to an external conductor is exposed from the outer shell.

A fixed contact 110 and a movable contact 120 for turning on and off the power supply side electric circuit and the load side electric circuit are disposed inside the container body, and an opening / closing mechanism unit 140 for driving the contacts to open and close. And detecting an abnormal current flowing in the electric circuit to act on the latch of the opening / closing mechanism 140 to perform a tripping operation of the opening / closing mechanism 140 to drive the fixed contact 110 and the movable contact 120 open. A tripping device unit 160 and an arc space 103 from which arc gas generated when the contactor is driven to open by the action of the tripping device unit 160 are provided. The container body 102 is formed with an arc gas discharge hole 1021 for discharging the arc gas discharged into the arc space 103 to the outside.

A connection terminal 1102 connected to the power source side conductor 201 is provided at one end of the fixed contact 110 so as to be exposed to the outside of the device body. The connection terminal 1102 is connected to the power source side conductor 201 by a terminal screw 1103. The connection terminal 1102 can be fixed and removed. The fixed contact 110 is bent along the inner wall of the container body 101 and extends into the container body 101, and a fixed contact 1101 is fixed to one end on the inner side.

A movable contact 120 is provided opposite to the fixed contact 1101 so that a movable contact 1201 is disposed. The movable contact 120 is held by an opening / closing mechanism 140 and is driven to open and close with the fixed contact 110. It is done.

The opening / closing mechanism unit 140 links the ON / OFF operation of the operation handle 150 with the opening / closing operation of the contactor, and when the tripping device 160 is activated, the tripping device 160 acts on the latch of the opening / closing mechanism unit 140. Thus, the tripping operation of the opening / closing mechanism is performed, and the contact is driven to open.

The opening / closing mechanism 140 includes a link 141 pivotally supported by the operation handle 150, a roller shaft 142 provided on the link 141, and a cross bar 143 common to each pole on which the roller shaft 142 abuts. The crossbar 143 reciprocally drives the movable contact 120 in the direction in which the movable contact 120 is pressed in the direction of the fixed contact 110 and the direction in which the movable contact 120 moves away from the fixed contact 110. A support plate 143 that regulates the movement trajectory of the roller shaft 142 by sliding the roller shaft 142 provided on the link 141 supported by the rotation shaft 151, and a latch portion that engages with the support plate 143. In the normal state, the rotation of the support plate 143 is restricted by the latch portion, while the support plate 143 and the trip bar are released. Is support plate 143 when it is provided with a trip bar 144 a part of which is journalled for rotation about said pivot shaft 151.

The movable contact 120 forms a part of the electric circuit in the body and detects an accident current such as an overcurrent or a short-circuit current generated in the electric circuit, thereby contacting the trip bar 144 and A tripping device 160 that rotates the trip bar 144 to release the engagement between the support plate 143 and the trip bar 144 is connected. As shown in FIG. 1, the tripping device 160 uses a bimetal displacement that is heated and bent by Joule heat generated by an overcurrent flow, and the coil is formed by forming an electric circuit in a coil shape. A device that detects an overcurrent by driving an iron piece by using an electromagnetic force generated by an overcurrent flowing in the circuit is well known. Normally, an electromagnet device for detecting a short-circuit current and performing an instantaneous trip operation is provided in the trip device, but is omitted for simplicity and is shown in FIG.

Further, the trip device 160 is connected to a load side terminal plate 130 on which a connection terminal 1302 to which the load side conductor 202 is connected is formed to form an electric circuit from the power source side to the load side in the circuit breaker. Yes.

Next, a configuration for realizing a function of detecting overheating in the connection terminal 1102 will be described. A bimetal 170 for detecting overheating is provided inside the container. In this embodiment, in order to detect abnormal overheating in the connection terminal 1102, the overheat detection bimetal 170 is fixedly attached in the vicinity of the connection terminal portion 1102. The bimetal 170 for detecting overheating is attached by crimping one end thereof in the vicinity of the connection terminal portion 1102 of the fixed contact 110 (fixed portion 171 in FIG. 1). In addition to the caulking, the attachment may be performed by various methods such as spot welding or pressure bonding. The other end of the bimetal 170 is provided along the vicinity of the inner wall of the vessel 102 and is exposed to the arc space 103.

On the other end side of the bimetal 170, an interlocking member 180 that is engaged with the bimetal 170 and interlocks with the bending of the bimetal is disposed. The interlock member 180 has a hole 181 into which a part of the bimetal 170 is inserted so that the bimetal 170 can be interlocked with the bimetal 170 when the bimetal 170 is bent from the initial position or when the bimetal 170 returns from the bent position to the initial position. Provided and engaged with the bimetal 170 via the hole 181. While the interlocking member 180 is engaged with the bimetal 170, the interlocking member 180 is engaged with the trip bar 144 on the other end side of the interlocking member 180 so as to abut against the trip bar 144 when the bimetal 170 is deflected and displaced. A portion 182 is provided.

The interlocking member 180 is formed of an elongated member made of an insulating material, and may be provided independently for each pole, or may be configured to be common to each pole similarly to a trip bar. In the case where each pole is common, for example, an engagement portion with a trip bar is provided in the width direction of the container, and an arm is provided from the engagement portion along the wall of the container to the bimetal for detecting overheat. The base may be provided with a hole extending to engage with each of the bimetals for detecting overheat, and the interlocking member may be provided in a substantially U shape as a whole. Accordingly, the arrangement and operation of the opening / closing mechanism are not obstructed, and the size of the container can be reduced because the peripheral portion of the inner wall of the container is used.

As a result, in the case where abnormal heat generation occurs due to, for example, contact resistance increasing over time in the connection terminal 1102, the heat generation of the connection terminal portion 1102 is transmitted to the overheating detection bimetal 170, whereby the bimetal 170 is In the same manner as when the interlocking member 180 rotates the trip bar 144 in accordance with the displacement and the tripping device 160 operates, the support plate 143 and the trip bar 144 are disengaged, Since the movable contact 120 operates so as to be separated from the fixed contact 110, the current flowing through the electric circuit can be interrupted, and the continuation of abnormal heat generation is prevented.

After the current is cut off, when the overheating of the terminal portion subsides, the overheating detection bimetal returns from the bent state to the position before the bending. For this reason, the effect on the trip bar 144 is that when the overheat detecting bimetal 170 is bent in the left direction in FIG. 1 due to overheating, the trip bar 144 is pressed and returned to the position before the overheat is cured and bent. In some cases (right side direction in FIG. 1), the engaging portion is biased so as not to act on the trip bar 144. Thereby, even when there is no abnormal heating, when an accident current occurs in the electric circuit, the tripping operation by the tripping device 160 is performed without being hindered.

The interlocking means between the interlocking member 180 and the bimetal 170 may be configured so that the bimetal engages with a notch formed by notching a part of the interlocking member, in addition to the means by the hole 181. You may comprise using connection members, such as a link and a spring, which connect these members.

Next, the case where the movable contact 120 is separated from the fixed contact 110 and the arc gas is discharged to the arc space 103 in the first embodiment will be described with reference to FIG.

When an accident current such as an overcurrent or a short-circuit current, particularly a short-circuit current, occurs in the electric circuit, an instantaneous trip operation is performed by the trip device, and the fixed contact 110 and the movable contact 120 are separated. At this time, an arc (electric arc) may be generated between the contacts, and arc gas is released into the arc space 103. Although it is necessary to discharge the arc gas appropriately outside the circuit breaker body, it is preferable to cool the arc gas in order to extinguish the arc at an early stage.

In this embodiment, since the bimetal 170 for detecting overheating is disposed in the vicinity of the arc gas discharge hole 1021 of the vessel 102, the bimetal has when the arc gas discharged to the arc space 102 touches the bimetal 170. A cooling effect corresponding to the heat capacity can be obtained, and when the arc gas is discharged from the arc gas discharge hole 1021 to the outside of the container, the gas temperature can be lowered and discharged. As a result, the arc in the arc space 102 is effectively extinguished, and compared with the case where the discharged arc gas is discharged as it is outside the body, the influence of the arc gas outside the body (stains the surroundings or burns the surroundings). Concern) can be reduced.

Moreover, in this embodiment, although the bimetal for overheat detection showed the form bent at the time of overheat detection in the direction of the arrow a in FIG. 2, depending on the structure of the opening / closing mechanism which the trip device 160 acts on, the arrow b It is assumed that the bimetal for overheating detection acts in the direction by bending when overheating is detected.
For this reason, it is preferable that the configuration of the engaging portion between the interlocking member 180 and the trip bar 144 is changed, and the configuration is selectively used according to the direction of action of the trip bar 144 of the opening / closing mechanism.

Further, a mechanism that reverses the direction in which the bimetal for overheat detection bends when overheat is detected may be provided so that the tripping device 160 acts on the opening / closing mechanism in either direction of arrows a and b in FIG. You may comprise as follows. As a reversing mechanism, for example, a rod-shaped member having a substantially central portion pivotally supported is provided. When the interlocking member 180 abuts on one end of the rod-shaped member, the other end is opposite to the direction in which the corresponding contact acts. What is displaced in the direction may be provided.

(Second embodiment)
Next, the abnormal overheat detection structure in the second embodiment will be described with reference to FIG.
In the second embodiment, in the bimetal 170 for overheating detection in the first embodiment, the current flowing through the electric path through the holes 172a, 172b,. A plurality are provided.

Since the bimetal 170 is provided with a plurality of holes through which arc gas permeates, the contact area between the arc gas generated in the arc space and the bimetal for overheat detection increases, and heat exchange between the arc gas and the bimetal is facilitated. As a result, the cooling efficiency can be improved, the arc gas can be easily released from the arc space, and the interruption capability can be further improved.

(Third embodiment)
Next, the abnormal overheat detection structure in the third embodiment will be described with reference to FIG.
In the third embodiment, a yoke 173 is formed from the vicinity of the fixing portion 171 toward the movable contact 120 in the overheat detection bimetal 170 in the first embodiment.

As shown in FIG. 4, the yoke 173 does not interfere with the movement of the movable contact 120 when the movable contact 120 is driven to open from the fixed contact 110 to the movable contact 120 from the side surface in the vicinity of the fixing portion 171 of the bimetal 170. The yoke pieces 173a and 173b are formed to extend in the direction. Further, when the arc generated between the fixed contact 1101 and the movable contact 1201 moves in the direction of the yoke by electromagnetic force, the center of the magnetic circuit constituted by the yoke 173 is the center of the fixed contact 1101 so that the arc is easily extended. The center is provided so as to be offset from the center, and the center when the arc is attracted to the inside of the yoke is configured to be offset from the center of the fixed contact 1101.

As a result, the arc generated between the stationary contact 110 and the movable contact 120 can be efficiently drawn toward the overmetal detection bimetal 170 by the yoke 173. When the arc is extended and the arc voltage is increased, the arc voltage is easily extinguished, and the function of detecting abnormal overheating can be provided while improving the interruption capability.

(Fourth embodiment)
Next, the abnormal overheat detection structure in the fourth embodiment will be described with reference to FIGS.
In the fourth embodiment, a der ion grid type arc extinguishing device 190 is provided in the arc space 103 of the circuit breaker 100, and the bimetal 170B for detecting abnormal overheating is fixed to the arc extinguishing device 190 so as to be integrally formed. Thus, the bending displacement of the bimetal 170B for detecting abnormal overheating is transmitted to the interlocking member 180.

The bimetal 170B for detecting abnormal overheating in the present embodiment is similar to the arc space 103 in the vicinity of the inner wall of the vessel 102 from the portion fixed by the fixing portion 171 to the bimetal 170 for detecting overheating in the first embodiment. In the same manner that the fixed contact 110 extends from the connection terminal portion 1102 along the inner wall of the container body, the fixed contact 110 is exposed from the portion fixed by the fixing portion 171. It is comprised so that it may extend along the inside of a container along 110. FIG.

In the extended end portion, fitting pieces 170B1 and 170B2 are formed so as to protrude in the same manner as the attachment method for fitting and fixing the grid 191 in the arc extinguishing device 190 to the arc extinguishing walls 193a and 193b. As a result, when the bimetal 170B for detecting abnormal overheating causes a bending displacement, the arc extinguishing device 190 performs a rotational movement with the fixing portion 171 as a substantially rotational center along with the displacement. An engaging portion 192 that engages with the hole 181 of the interlocking member 180 is formed at the end of the arc extinguishing device 190 on the container 102 side. A contact action is performed on 144.

That is, when the bimetal 170B bends from the initial position or returns from the bent position to the initial position, the interlocking member 180 moves following those displacements, and as a result, the interlocking member 180 moves to the trip bar. 144 can be brought into abutment action.

In the arc extinguishing device 190, the derion grid may be omitted.

(Fifth embodiment)
Next, the abnormal overheat detection structure in the fifth embodiment will be described with reference to FIG.
In the fifth embodiment, the bimetal 170B for detecting abnormal overheating in the fourth embodiment is formed separately from the arc extinguishing device 190. Also in this embodiment, the arc extinguishing device 190C shown in the figure can receive the displacement of the bimetal 170C for detecting abnormal overheating and transmit it to the interlocking member 180, and the interlocking member 180 and the arc extinguishing device 190C can be transmitted. The engaging part is the same.

In the present embodiment, the arc extinguishing device 190C is pivotally supported in the body, and the bimetal 170C for detecting abnormal overheating is disposed close to the lower side in the drawing of the arc extinguishing device 190C. When the bimetal is bent, the displacement is transmitted to the arc-extinguishing device 190C, and the arc-extinguishing device 190C rotates around the shaft support portion. As a result of the rotation of the arc extinguishing device 190C, the interlocking member 180 abuts on the trip bar 144 as in the fourth embodiment.

The interlocking member 180 is configured to be biased by a latch or a spring to the side opposite to the bending direction when the overheating detection bimetal is overheated, and the arc-extinguishing device 190C is always arranged at a predetermined position. I work like that. Further, while omitting these latches and springs, the clearance of the engagement between the interlocking member and the overheat detection bimetal is appropriately adjusted so that the arc extinguishing device 190C is placed at a predetermined position by the overheat detection bimetal. You may comprise.

(Sixth embodiment)
Next, the abnormal overheat detection structure in the sixth embodiment will be described with reference to FIG.
In the sixth embodiment, the bimetal 170 for detecting abnormal overheating in the first embodiment is fixed to the fixed contact in the vicinity of the fixed contact 1101 of the fixed contact 110 so as to substantially surround the fixed contact 1101. The extending member 170D1 extending with the engaging portion 192b engaged with the interlocking plate 180 is fixed to one end.

The extension member 170D1 is formed of a heat-resistant member such as ceramic in addition to the iron material, thereby improving the corrosion resistance and insulation against arc gas.

The bimetal for detecting overheating in this embodiment is a structure that is used as a traveling plate for arc generated in the arc space and a cooling plate for arc gas, which is fixed in the vicinity of the fixed contact. Thereby, in addition to the structure using the said yoke, consumption of a contact can be suppressed.

The yoke may be formed integrally with the overheat detection bimetal so as to have a function as an arc traveling plate and a function as a yoke. Instead of using the first extending member 170D1, One end of the overheating detection bimetal 171D itself may be extended.

The circuit breaker having an abnormal heating detection function according to the present invention includes a bimetal on which the temperature of the external wire terminal acts, and when the temperature of the external wire connection terminal becomes abnormally high, the bimetal acts on the mechanism portion. Compared to the conventional breaker, the contactor is driven open, so it is easy to add a bimetal that acts on the temperature of the external wire connection terminal and a member that interlocks the bending displacement caused by the heat of the bimetal with the opening and closing mechanism. With a simple modification, a circuit breaker having an abnormal overheat detection function can be provided at low cost.

In addition, since the bimetal on which the temperature of the external wire connection terminal acts can be provided independently for each pole regardless of the number of poles of the circuit breaker, there is no problem in ensuring insulation between the poles, and The abnormal overheat detection function can be provided for all the poles.

In addition, the interlocking member that interlocks the bimetal curve with the opening / closing mechanism may be provided for each pole, or may be configured as one member in the circuit breaker across a plurality of poles. Since the interlocking member can be formed of an insulator made of a resin such as plastic, even if it is formed of a single member across a plurality of poles, there is no problem in securing insulation between the poles.

In addition, in circuit breakers used in power distribution devices such as distribution boards, the arrangement of the connection terminals on the power supply side to connect external wires and the connection terminals to be connected to the internal equipment side is almost fixed. The connection terminals to be connected have almost no opportunity to remove them after tightening the terminal screws with a certain standard by the manufacturer of the distribution device, so the terminal temperature is only at the connection terminals to which the external wires are connected. A bimetal for detecting abnormal overheating may be provided.

In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of this invention.

For example, when abnormal overheating occurs at the connection terminal, current is not flowed by shutting off, so overheating is also subsided. However, when the operation handle is turned on as it is after being shut off, there is a possibility that current flows again and abnormal overheating occurs again.

Therefore, when the abnormal overheat is detected and shut off, the interlocking member is moved by a predetermined sliding amount by the internal unit 102 so that the latch of the trip bar remains released so that the movable contact is not driven again. It is preferable that the interlocking member stays at the moved position even when the bimetal for detecting abnormal overheating is returned from the bent state to the original state by supporting with dynamic resistance. The predetermined sliding resistance is smaller than the force generated when the bimetal that detects the abnormal overheating is bent, and more than the force when the trip lever returns to the original state. Should be provided so as to maintain a large relationship.

In the embodiment, the tripping device has been described as a so-called thermal-electromagnetic type, but may be configured as a complete electromagnetic type. In addition, as for the opening / closing mechanism, a so-called late entry is shown, but it may be configured as a fast entry.

DESCRIPTION OF SYMBOLS 100 Circuit breaker 101 Body 102 Body 103 Arc space 110 Stationary contact 1101 Stationary contact 1102 Connection terminal 1103 Terminal screw 120 Movable contact 1201 Movable contact 130 Load side terminal board 1301 Load side conductor 1302 Connection terminal 1301 Terminal screw 140 Opening and closing Mechanism 141 Link 142 Roller shaft 143 Support plate 144 Crossbar 150 Operation handle 151 Rotating shaft 160 Tripping device 170 Overheating detection bimetal 171 Adhering portion 172 Hole 173 Yoke 180 Interlocking member 181 Hole portion 182 Engaging portion 190 Arc extinguishing device 201 Power supply side conductor 202 Load side conductor

Claims (6)

Inside the body,
An open / close mechanism for driving the fixed contact and the movable contact to open and close the electric circuit on the power source side and the electric circuit on the load side; and
A tripping device for detecting an abnormal current flowing in the electric circuit and acting on a latch of the opening / closing mechanism to perform a tripping operation of the opening / closing mechanism to open the fixed contact and the movable contact;
An arc space from which arc gas generated when the contactor is driven to open by the action of the trip unit is released; and
Outside the body,
A circuit breaker provided by exposing the connection terminal portion connected to the electric circuit inside the body and connected to the external power supply conductor,
A bimetal for overheating detection that detects overheating in the connection terminal portion,
The conductor constituting the connection terminal portion is fixed to the inner side of the container and is exposed to the arc space in the vicinity of the contact,
A circuit breaker having an abnormal overheat detection structure characterized by comprising an interlocking member that engages with the bimetal for detecting overheat and interlocks by receiving the bending of the bimetal and acting on the latch of the opening and closing mechanism part vessel. 2. The circuit breaker having an abnormal overheat detection structure according to claim 1, wherein the overheat detection bimetal is provided with a plurality of holes through which arc gas permeates on a surface facing the movable contact. 3. The circuit having an abnormal overheat detection structure according to claim 1, wherein the overheat detection bimetal is configured by forming a yoke from the bimetal toward the movable contact. 4. Circuit breaker. In the arc space,
An arc extinguishing device that is pivotally supported so as to rotate when the bimetal for detecting overheating abuts is provided,
4. An interlocking member that is engaged with the arc extinguishing device, interlocks in response to rotation of the arc extinguishing device, and acts on a latch of the opening / closing mechanism portion is provided. A circuit breaker having the abnormal overheat detection structure according to any one of the above. The arc extinguishing device is provided with a grid that divides the arc, and an arc extinguishing wall that supports the grid,
5. The circuit breaker having an abnormal overheat detection structure according to claim 4, wherein said overheat detection bimetal is supported by an arc extinguishing wall so that the arc extinguishing device and the bimetal are integrally formed. The overheat detection bimetal is fixed so as to substantially surround the fixed contact in the vicinity of the fixed contact of the fixed contact, and a part of the overheat detection bimetal is engaged with the interlocking member. A circuit breaker having the abnormal overheating structure according to claim 1 or 2.

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