JPH10208909A - Current limiter employing ptc element and circuit breaker equipped with current limiter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small current limiter excellent in maintainability in which the power loss is reduced in a steady state, and a small circuit breaker excellent in maintainability in which breaking capacity is enhanced. SOLUTION: The current limiter 10 comprises a thin planar PTC element plate 11 sandwiched by upper and lower terminal plates 12, 13, a heat sink 14 applied tightly to the terminal plate 12 in order to absorb heat generated from the PTC element plate 11, and a heat dissipator 16 with a large number of fins 16a mounted on the heat sink 14 through an insulation plate 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current limiting device for protecting a power distribution system or power equipment disposed in a power distribution system or the like from an excessive current such as a short-circuit current flowing in a power distribution system or the like. The present invention relates to a circuit breaker having a current limiter, and more particularly to a current limiter using a PTC element and a circuit breaker having the current limiter.

[0002]

2. Description of the Related Art Conventionally, in order to protect a distribution circuit from an overcurrent such as a short-circuit current or an overload current, a wiring circuit breaker provided with an opening / closing mechanism, a trip device, an overcurrent detection device, and the like in the distribution circuit. (Molded Case Circuit Breakers (MCC
B), which is hereinafter referred to as MCCB), and automatically cuts off the power distribution circuit when a short-circuit current or an overload current flows through the power distribution circuit. This MCCB
Is to perform a pulling-out operation to draw an operation characteristic curve as shown in FIG.

In FIG. 14 (the vertical axis in FIG. 14 represents a logarithmic scale), 100% of the rated current In (1.0 I
In the steady region where n) flows, this MCCB does not perform the pulling-off operation, and is 125% (1.25%) of the rated current In.
In the overcurrent region of (In) to 1000% (10In), the MCCB performs the pulling-off operation within 120 minutes to 10 seconds, and in the short circuit region longer than that, within approximately 0.02 seconds (one cycle at 50 Hz). MCCB indicates that a pull-off operation is performed. Note that the maximum current that can flow through the MCCB is determined by the contact point, the electrode structure, and the like, and is determined as the breaking capacity of the MCCB.

[0004] In order to increase the breaking capacity of this circuit breaker, a circuit breaker for wiring provided with some current limiting device such as an electromagnetic repulsion mechanism, a current limiting fuse, and a current limiting element has come into practical use. A circuit breaker provided with an electromagnetic repulsion mechanism has been proposed, for example, in Japanese Patent Application Laid-Open No. 3-102724. FIG. 15 shows a configuration of an electromagnetic repulsion mechanism proposed in the above-mentioned Japanese Patent Application Laid-Open No. 3-102724.

[0005] In FIG. 15, a fixed contact 2 fixed to one end of a fixed conductor 1 is provided, and a conductor 1 b having the fixed contact 2 is a conductor 1 connecting the terminal 7 and the connection conductor 6.
It stands substantially perpendicular to a. The connection conductor 6 is fixed on the terminal 8 of the circuit breaker (not shown). One end of the movable contact 3 is provided with a movable contact 4 facing the fixed contact 2, and a shunt 5 is fixed to the other end of the movable contact 3 and connected to a terminal 7.
A pin 3 for supporting the movable contact 3 is provided below the movable contact 3.
The pressure contact spring 3b is mounted on the pin 3a to urge the movable contact 3 toward the fixed conductor 1. An arc extinguishing grid 9 for extinguishing the arc is disposed above these two contacts 2 and 4.

When an overcurrent flows due to a short circuit accident or the like in the electromagnetic repulsion mechanism configured as described above, an electromagnetic repulsion force acting between the movable contact 4 and the fixed contact 2 or between the movable contact 3 and the fixed conductor 1. Are repelled against the urging force of the pressure contact spring 3b, the movable contact 4 and the fixed contact 2 are separated from each other,
An arc A is generated in between. At this time, since the current I ₁ flowing through the bottom conductor portion 1a of the fixed conductor 1 and the arc A are currents in different directions, the arc A is driven to the arc extinguishing grid 9 side. As described above, when the arc A is driven toward the arc-extinguishing grid 9, the arc length increases, and the arc A is cooled by the arc-extinguishing grid 9, so that the arc voltage also increases.
As a result, the obtained high arc voltage has the same effect as inserting a high resistance in the electric circuit, and the overcurrent is limited and suppressed, that is, the current is limited.

[0007]

However, in the circuit breaker provided with the above-described electromagnetic repulsion mechanism, the arc A generated between the contacts 4 and 2 is driven toward the arc-extinguishing grid 9 to reduce the arc length. In order to increase the arc voltage by increasing the arc voltage by cooling the arc by the arc-extinguishing grid 9, the arc-extinguishing grid 9 must be formed large. There is a problem that the vessel becomes large.

On the other hand, in a circuit breaker provided with a current-limiting fuse, once the current-limiting operation is performed, the current-limiting fuse is blown. Therefore, the blown current-limiting fuse must be replaced. The problem of badness arises. Further, a circuit breaker provided with a current limiting element such as a resistance element causes a problem that power loss is increased due to a resistance voltage drop in a steady region where a rated current flows, and an overload current flows. In the overcurrent region, FIG.
As is apparent, a problem arises in that the cutoff time is prolonged due to the reduction of the overload current.

Here, as one of the resistance elements, when the temperature of the element rises and reaches a predetermined temperature (resistance transition temperature or phase transition temperature, hereinafter referred to as resistance transition temperature), the resistance value sharply increases. Devices with an increasing positive temperature coefficient of resistance (PTC (Positive Temperature Coefficient)
A thermistor (hereinafter referred to as a PTC element) is known.
Therefore, the present invention has a low resistance state in a steady region where a rated current flows and an overcurrent region where an overload current flows, and reaches a resistance transition temperature in a short circuit region where a short circuit current flows and the resistance value rapidly increases. If a PTC element whose resistance value increases is used as a current limiting element, the power loss is small in a steady state region, has a characteristic that does not affect the operating characteristics of the circuit breaker in an overcurrent region, and has a characteristic in a short circuit region. It is based on the knowledge that a current limiting effect will occur due to a sudden increase in resistance, and it is possible to obtain a current limiter that is small and has excellent maintainability with reduced power loss at steady state. An object of the present invention is to obtain a small circuit breaker having a current limiting device and having an increased breaking capacity and excellent in maintainability.

[0010]

SUMMARY OF THE INVENTION The present invention provides a PTC element having a positive temperature coefficient of resistance, which has a resistance value that rapidly increases when a predetermined resistance transition temperature is reached. When an overcurrent such as a short-circuit current flows, the temperature of the PTC element rises, and when the temperature reaches a predetermined resistance transition temperature, the resistance value rapidly increases, and a PTC element that suppresses the overcurrent is used. In order to solve the above-mentioned problem, in the invention according to claim 1, the PTC element is formed in a thin plate shape, and one end of the thin plate-shaped plane is connected to the power supply side of the electric circuit. A thin PTC element plate whose other end is connected to the load side of the electric circuit, and a heat generated in the thin PTC element plate which is disposed in contact with the thin PTC element plate to absorb the heat. Storage made of heat storage material that stores heat If, in that a heat radiator made of good thermal conductive material for dissipating heat stored in the heat is disposed in contact with the heat accumulator in the heat accumulator.

Thus, the PTC element is formed in a thin plate shape,
By connecting one end of this thin plate-shaped plane to the power supply side of the electric circuit and connecting the other end of this thin plate-shaped plane to the load side of the electric circuit, the energizing direction of the thin PTC element plate becomes the thickness direction, In a state in which the rated current flows in a steady state, the conduction resistance decreases and the power loss decreases. Also, in the overcurrent region where the overload current exceeding the rated current flows,
When the PTC element plate generates heat due to the Joule heat, the generated heat is conducted to the heat accumulator.

Thus, even if an overload current flows through the PTC element plate for a long time and the PTC element plate generates heat, this heat is successively absorbed by the regenerator and the heat absorbed by the regenerator is radiator. As a result, the PTC element plate can be prevented from reaching the resistance transition temperature.

On the other hand, when a short-circuit current flows through an electric circuit, an excessive current flows within a short time of 0.02 seconds or less at maximum, so that the electric energy applied to the PTC element plate becomes Joule heat, and the temperature of the PTC element plate increases. Rises sharply. Then, the PTC element plate reaches the resistance transition temperature, the resistance value increases rapidly, and the short-circuit current is suppressed (current limit), and the short-circuit current decreases.

According to the second aspect of the present invention, a terminal plate having one end connected to the power supply side of the electric circuit is provided on one surface of the thin PTC element plate,
The other surface of the element plate is provided with a terminal plate having one end connected to the load side of the electric circuit. By connecting the thin plate-like PTC element plate to each terminal plate in this way, the direction of current supply to the thin plate-like PTC element plate becomes its thickness direction, and the current-flow resistance in a steady state decreases, thereby reducing power loss.

According to the third aspect of the present invention, the heat accumulator is configured to hermetically seal a low melting point metal filled in a metal container, and the heat dissipator includes a number of heat dissipating fins. That's what I did. When the heat accumulator is configured as described above, when the thin PTC element plate generates heat, the low melting point metal filled in the heat accumulator is melted, and the heat generated by the PTC element plate is stored by the heat of fusion. . By utilizing the heat of fusion, the volume of the regenerator can be smaller than that made of a single metal (eg, copper), and the current limiter can be downsized. Further, since the heat radiator has a large number of heat radiation fins, the heat absorbed by the heat accumulator can be released more efficiently than the heat radiation fins.

According to the present invention, the terminal plate and the regenerator are integrally formed to form a terminal plate that also serves as a regenerator, and the integrally formed terminal that also serves as a regenerator. That is, the plates are connected to both surfaces of the thin PTC element plate. By integrally forming the terminal plate and the heat accumulator in this manner, even if the terminal plate and the heat accumulator have the same volume as those formed separately, the overall thickness can be reduced. This makes it possible to reduce the size of this type of current limiter.

According to the fifth aspect of the present invention, the terminal plate, the heat storage device, and the heat radiator are integrally formed to form a terminal plate that is also used as the heat storage device and the heat radiator. The terminal plate that also serves as a heat storage unit and a radiator
That is, it is connected to at least one surface of the TC element plate. By integrally forming the terminal plate, the heat accumulator, and the heat radiator in this way, the overall thickness is further reduced even if the terminal plate, the heat accumulator, and the heat radiator are formed separately from each other. Therefore, this type of current limiter can be further miniaturized.

According to a sixth aspect of the present invention, the thin-film PTC element plate, the terminal plate, the heat accumulator, and the heat radiator are formed so that their respective planar shapes become the same square shape, respectively. The whole is formed in a substantially prismatic shape. When the current limiting device is formed in a substantially prismatic shape as a whole, space saving can be achieved when the current limiting devices are arranged in three phases and connected to a connection terminal of an MCCB (breaker).

In the seventh aspect of the present invention, the thin-film PTC element plate, the terminal plate, the heat accumulator, and the heat radiator are formed so that their respective planar shapes are circular with the same diameter, and the current is limited. The entire vessel was formed in a substantially cylindrical shape. Generally, since the PTC element plate is manufactured in a circular shape,
If this type of current limiter is formed in a substantially cylindrical shape, this type of current limiter can be manufactured at low cost and can be easily manufactured.

According to the present invention, the above-mentioned PTC element is formed in the shape of a half-width cylinder having a U-shaped cross section to form a half-width cylindrical PTC element body, and the outer surface of the half-width cylindrical PTC element body is tightly closed. And an outer terminal body having a U-shaped cross section and being electrically connected to the same half-width cylindrical PTC element body and having a protruding portion in the longitudinal direction thereof, and a half-width cylindrical PTC element body. A heat storage material that is tightly fixed to the surface and is electrically connected to the half-width cylindrical PTC element body to absorb and store heat generated in the half-width cylindrical PTC element body and has a protruding portion in a longitudinal direction thereof. An inner terminal body also serving as a regenerator, and a radiator made of a good heat conducting material that is tightly fixed to the inner terminal body also serving as a regenerator and radiates heat stored in the inner terminal body also serving as the regenerator. That you have.

As described above, the PTC element is formed in a half-width cylindrical shape having a U-shaped cross section to form a half-width cylindrical PTC element body. When the terminal body is fixed and the inner terminal body also serving as a heat storage material made of a heat storage material is fixed to the inner surface of the half-width cylindrical PTC element body, current flows in a direction perpendicular to the U-shaped cross section of the half-width cylindrical PTC element body. Therefore, in a state where the rated current flows in a steady state, the conduction resistance decreases and the power loss decreases.

Further, the heat generated by the PTC element body is conducted from the three surfaces of the inner terminal body which also serves as a heat accumulator.
It is possible to efficiently absorb the heat of the heated PTC element body. For this reason, even if an overload current flows through the PTC element for a long time and the PTC element generates heat, this heat is successively absorbed by the inner terminal that also serves as a regenerator and is transferred to the inner terminal that also serves as a regenerator. Since the absorbed heat is released from the radiator, the PTC element can be prevented from reaching the resistance transition temperature even if an overload current in the overcurrent region flows through the PTC element.

According to the ninth aspect of the invention, one of the outer terminal body and the protrusion of the heat storage and inner terminal is connected to the power supply side of the electric circuit, and the other is connected to the load side of the electric circuit. In addition, the inner terminal body also serving as a heat storage unit is configured by hermetically sealing a low melting point metal filled in a metal container, and the radiator is provided with a large number of radiating fins.

By connecting the PTC element body to the outer terminal body and the regenerator / inner terminal in this way, the direction of conduction of the PTC element body is perpendicular to the U-shaped cross section, and the conduction resistance is reduced. It becomes possible. Also, if the low-melting-point metal is hermetically sealed to form an inner terminal that also serves as a heat storage device,
When the PTC element generates heat, the low-melting-point metal filled in the heat storage internal terminal is melted, and the heat generated by the PTC element due to the heat of fusion is stored. By utilizing the heat of fusion, the volume of the regenerator can be smaller than that made of a single metal (eg, copper), and the current limiter can be downsized. Further, since the heat radiator has a large number of heat radiation fins, the heat absorbed by the heat accumulator can be released more efficiently than the heat radiation fins.

According to a tenth aspect of the present invention, the above-mentioned PTC element is formed into a cylindrical shape to form a cylindrical PTC element body, and the PTC element is tightly fixed to an inner surface of the cylindrical PTC element body. A cylindrical inner terminal body electrically connected to the element body and having a protruding portion in the longitudinal direction; and a cylindrical PTC element body which is tightly fixed to the outer surface of the cylindrical PTC element body and electrically connected to the cylindrical PTC element body. A cylindrical regenerator made of a heat storage material that is connected and absorbs heat generated in the cylindrical PTC element body and stores the heat, and is tightly fixed to the cylindrical regenerator and electrically connected to the cylindrical regenerator In addition, the heat storage device of the present invention includes a heat-dissipating heat stored in the cylindrical heat accumulator and a cylindrical heat dissipating outer terminal body made of a good heat conductive material having a protruding portion in a longitudinal direction thereof.

As described above, the PTC element is formed in a cylindrical shape to form a cylindrical PTC element body, and a cylindrical inner terminal body is fixed to the inner surface of the cylindrical PTC element body, and the cylindrical PTC element body is formed.
When a cylindrical heat storage unit and an outer terminal body also serving as a cylindrical heat radiator are fixed to the outer surface of the C element body, current flows in the radial direction with respect to the cross section of the cylindrical PTC element body, so that the rated current in a steady state is reduced. In a flowing state, the current-carrying resistance is reduced and the power loss is reduced.

Further, since the heat generated by the PTC element is conducted to the outer cylindrical heat storage unit from the entire circumferential surface, it is possible to efficiently absorb the heat of the generated PTC element. . Therefore, even if an overload current flows through the PTC element for a long time and the PTC element generates heat,
This heat is successively absorbed by the cylindrical heat accumulator, and the heat absorbed by the cylindrical heat accumulator is released from the outer terminal body also serving as the cylindrical heat radiator. , The PTC element body can be prevented from reaching the resistance transition temperature.

According to the eleventh aspect of the present invention, either one of the outer terminal body serving as the cylindrical heat radiator and the protrusion of the cylindrical inner terminal body is connected to the power supply side of the electric circuit,
The other end is connected to the load side of the electric circuit, and the cylindrical regenerator is configured by sealing the low melting point metal filled in the metal container, and is connected to the outer surface of the outer terminal body also serving as the cylindrical heat radiator. That is, a large number of heat radiation fins are provided.

By connecting the cylindrical PTC element body to the outer terminal body and the regenerator / inner terminal in this way, current flows in a radial direction with respect to the cross section of the cylindrical PTC element body. When the current flows, the conduction resistance decreases and the power loss decreases. Further, if the low-melting-point metal is sealed to form a cylindrical regenerator, when the PTC element generates heat, the low-melting-point metal filled in the regenerator melts, and the heat of fusion causes the PTC element to generate heat. The stored heat is stored. By utilizing the heat of fusion,
The volume of the heat accumulator can be made smaller than that made of a single metal (for example, copper), and the current limiter can be downsized. In addition, since the outer terminal body also serving as a cylindrical heat radiator has a large number of heat radiating fins on its outer surface, the heat absorbed by the heat accumulator can be released more efficiently than the heat radiating fin.

According to the twelfth aspect of the present invention, the above-mentioned PTC element is formed in a plate shape to form a plurality of PTC element plates, and has a protruding portion in the longitudinal direction and a triangular cross section in the height direction. Provided at least one projection part,
A lower terminal body made of a heat storage material that absorbs and stores heat generated in the PTC element plate, and a groove having a triangular cross section that has a protrusion in the longitudinal direction and that fits into the protrusion of the lower terminal body. An upper terminal body that is provided at least one in the height direction and is made of a heat storage material that absorbs heat generated in the PTC element plate and stores the heat; and heat that is provided above the upper terminal body and is stored in the upper terminal body. A heat dissipating body made of a good heat conductive material for dissipating heat, and a groove having a triangular cross section of the upper terminal body which fits into the inclined surface of the triangular protruding section of the lower terminal body. The PTC element plate is narrowly attached to the inclined surface.

As described above, the PTC element is formed in a plate shape,
A TC element plate between the inclined surface of the triangular cross-sectional projection of the lower terminal body and the inclined surface of the triangular groove of the upper terminal body fitted in the triangular groove of the same cross-section; When it is narrow, power is supplied in the thickness direction of the cross section of the PTC element plate, so that the current flow resistance is reduced and the power loss is reduced when the rated current flows in a steady state.

Further, the heat generated by the PTC element plate is made up of the heat storage material on both sides of the PTC element plate, and is conducted to both lower terminals from both sides of the PTC element plate. It becomes possible to absorb well. For this reason, even if an overload current flows through the PTC element plate for a long time and the PTC element plate generates heat, this heat is successively absorbed by the upper and lower terminals and also absorbed by the upper terminals. Since heat is radiated from the heat radiator, it is possible to prevent the PTC element plate from reaching the resistance transition temperature even if an overload current in the overcurrent region flows through the PTC element plate.

According to the thirteenth aspect, one of the protruding portions of the upper terminal body and the lower terminal body is connected to the power supply side of the electric circuit, and the other is connected to the load side of the electric circuit. The upper terminal body and the lower terminal body are configured by hermetically sealing a low melting point metal filled in a metal container, and are provided with a large number of radiating fins on the outer surface of the radiator.

As described above, if the upper and lower terminals are formed by sealing the low-melting-point metal with the low-melting-point metal, the low-melting-point metal filled in the two terminals is melted when the PTC element plate generates heat. The heat generated by the PTC element plate due to the heat is stored. By utilizing the heat of fusion, the volume of both terminal bodies can be made smaller than that made of a single metal (for example, copper), and the current limiter can be downsized. Further, since a large number of radiating fins are provided on the upper outer surface of the upper terminal body, the heat absorbed by the upper terminal body is released more efficiently than the radiating fins.

In the fourteenth aspect of the present invention, the above-mentioned PTC element uses a cristobalite-based ceramic having a small ordinary-temperature resistivity and a large resistance increase with respect to the ordinary-temperature resistivity. Since the cristobalite-based ceramics have a small ordinary temperature resistivity, the current supplied to the electric circuit at normal time flows through the PTC element without power loss. In addition, since the cristobalite-based ceramics have a large increase in resistance with respect to the normal temperature resistivity, when an overcurrent such as a short-circuit current flows through the element, the resistance value rapidly increases. Can be reliably flow-limited.

Further, according to the present invention, when an overcurrent such as a short-circuit current flows in the electric circuit, the temperature rises, and when the temperature reaches a predetermined resistance transition temperature, the resistance value rapidly increases to suppress this overcurrent. A circuit breaker provided with a current limiter using a PTC element in which a current limiter using a PTC element is connected to a power supply side thereof. PT when overload current flows in the area
The C element should not reach the resistance transition temperature,
When a short-circuit current flows through an electric circuit, the PTC element reaches a resistance transition temperature to suppress the short-circuit current. With this configuration, when the electric circuit is short-circuited and a short-circuit current flows through the circuit breaker, the current limiter suppresses (short-circuits) the short-circuit current. Can be greatly improved.

According to a sixteenth aspect of the present invention, the current limiter according to the fifteenth aspect is the current limiter according to any one of the first to fourteenth aspects. When the current limiter according to any one of claims 1 to 14 is connected to this circuit breaker and used, the current limiting effect is large, so that a circuit breaker excellent in breaking capacity can be obtained.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 is a perspective view schematically showing a current limiter using a PTC element according to a first embodiment of the present invention. Generally, the resistance value of a resistance element decreases in proportion to its cross-sectional area, and decreases in inverse proportion to its length.Therefore, when using a material having resistivity at a low resistance, increase the surface area and increase the surface area. It is necessary to shorten the length.

Therefore, as shown in FIG. 1, in the current limiter 10 of the first embodiment, an upper terminal plate 12 and a lower terminal plate 13 are connected to upper and lower surfaces of a PTC element plate 11 formed in a thin plate shape.
A regenerator 14 for absorbing heat generated when the PTC element plate 11 generates heat is connected to the upper portion of the upper terminal plate 12 in close contact with the terminal plate 12, and a radiator is provided on the upper portion of the regenerator 14 via an insulating plate 15. 16 is provided.

Here, the PT for forming the PTC element plate 11 is
As the C element, the room temperature resistivity ρ (for example, ρ = 0.1Ω)
Cm) is small, and the rate of increase in resistance with respect to the normal temperature resistivity (for example, 4000 times the normal temperature resistivity ρ) is large,
In addition, it is preferable to use a cristobalite-based ceramic having a resistance transition temperature (Tc) of about 200 to 240 ° C. P made of this cristobalite ceramic
The TC element has a temperature (° C.)-Resistivity (ρ) characteristic as shown in FIG.
When the resistance transition temperature (Tc) is reached, the resistivity (ρ) becomes the maximum (ρmax). In the first embodiment, the PT made of the cristobalite-based ceramic is used.
The C element is formed in a thin plate shape to form a PTC element plate 11. A PTC element made of cristobalite-based ceramics is used in another embodiment of the present invention described later.

As the PTC element, other than cristobalite ceramics, Cr ₂ O ₃ or Al ₂ O ₃
V ₂ O ₃ based ceramics obtained by solid solution of lead titanate (PBT
iO ₃ ) ceramics, bismuth titanate (BiTi)
O ₃ ) ceramics or solid solutions thereof may be used. Further, it can be formed of a synthetic resin made of a polyethylene-carbon composite material or a polyolefin-carbon composite material.

Each of the terminal plates 12 and 13 is formed of a metal such as copper, aluminum, stainless steel or the like having good conductivity and good heat conductivity in a strip shape. Then, these two terminal plates 12 and 13 are sandwiched in the thickness direction of the PTC element plate 11 so that a current flows in the thickness direction of the PTC element plate 11, and are bonded, brazed or welded with a conductive adhesive. And is integrated with the PTC element plate 11. In this way, the terminal plates 12, 13 are PT
When connected to the C element plate 11, the thin PTC element plate 11
Is conducted in the thickness direction, so that even if a current flows through the PTC element plate 11, the conduction resistance is reduced and the power loss is reduced. In addition, these two terminal boards 12, 13
At each end, mounting holes 12a and 13a are provided.

As shown in FIG. 2, the regenerator 14 includes a metal container 14a made of a metal having good thermal conductivity, such as copper, aluminum, and stainless steel, and a low melting point sealed in the metal container 14a. Metal (e.g., metal having a low melting point (e.g., 130 to 150 [deg.] C.) such as a lead-tin alloy or solder) 14b
It consists of. The heat storage unit 14 is fixed to at least one of the terminal plates 12 and 13 by bonding with an adhesive, brazing, welding, or the like (FIG. 1 shows an example in which the heat storage unit 14 is disposed on the terminal plate 12 side). ) To be integrated with both terminal boards 12 and 13. Therefore, PTC
The element plate 11, the terminal plates 12, 13 and the regenerator 14 are integrated.

As a result, an overload current in the overcurrent region flows through the PTC element plate 11, and the Joule heat causes P
When the TC element plate 11 generates heat, the generated heat is conducted to the regenerator 14. Then, it is sealed in the metal container 14a,
The filled low melting point metal 14b absorbs this heat and melts when it reaches its melting point. Thereby, the PTC element plate 11
Even if the overload current flows for a long time and the PTC element plate 11 generates heat, this heat is successively generated by the low melting point metal 14b.
, The PTC element plate 11 can be prevented from reaching the resistance transition temperature (Tc = 200 to 240 ° C.), and does not affect the operation of an MCCB (circuit breaker) described later.

The heat dissipating body 16 is composed of a heat dissipating fin in which a plurality of fins 16a are integrally formed on a plate made of aluminum alloy having good thermal conductivity. In order to electrically insulate the heat radiator 16 from the heat accumulator 14, it is integrally fixed to the upper portion of the heat accumulator 14 via an insulating plate 15 having good heat resistance. Thereby, the heat generated from the PTC element plate 11 stored in the heat storage device 14 is released from the radiator 16 into the outside air.

FIG. 4 is a front view showing the outer shape of the MCCB (circuit breaker) 100.
Is a main contact connected to an electric circuit (not shown), a switching mechanism for opening and closing the main contact, an arc-extinguishing chamber for extinguishing an arc generated when the main contact is opened, and a switching mechanism for overload current or short-circuit current. A release device for releasing the main contact and releasing the main contact, an operation switch 101 for operating the opening / closing mechanism to put the main contact into the electric circuit, and a power supply side for connecting the MCCB (circuit breaker) 100 to the electric circuit on the power supply side Terminals 102X, 102Y,
102Z and a load-side terminal for connecting an MCCB (circuit breaker) 100 (not shown) to an electric circuit on the load side.

Then, the mounting holes 13a, 13a, 1 of the terminals 13, 13, 13 of the current limiting devices 10, 10, 10 are set.
3a is connected to the power supply side terminals 102X and 102 of the MCCB 100.
Y, 102Z, respectively, and screw them in. The mounting holes 12a, 12a, 12a of the terminals 12, 12, 12 of the respective current limiters 10, 10, 10 are connected to the electric wires X, Y, Z on the power supply side.
, And the screws X, Y, Z on the power supply side and the MCCB 100 are connected to the respective current limiters 10,
They are connected via 10, 10. On the other hand, each load-side electric wire is connected to a load-side terminal (not shown) for each phase. Thereby, MCCB (breaker) 1 provided with current limiter 10 for each phase
00 will be connected to the electric circuit.

Next, the operation of the MCCB (breaker) 100 having the current limiting device 10 for each phase connected as described above will be described. First, the operation in a normal state (the steady region in FIG. 14) will be described. When the operation switch 101 is operated to operate the opening / closing mechanism and the main contact is turned on, the power of the power supply (not shown) is reduced by the current limiter 10 and the MCCB 100. , And a rated current (In in FIG. 14) flows through this electric circuit. At this time, the current limiter 1
Since the resistance value of the PTC element plate 11 of 0 is small, power is supplied to the load without power loss.

Here, if an overload current (1.25 to 10 In in FIG. 14) flows to the load side of the electric circuit for some reason (overcurrent region in FIG. 14), the current limiter 10
PTC element plate 11 has a rated current (In) of 1.25 to
10 times overload current flows, and the Joule heat causes PT
The C element plate 11 generates heat. Then, the generated heat is conducted to the regenerator 14 to be stored. Then, as shown in FIG. 2, the low melting point metal 14b sealed and filled in the metal container 14a absorbs this heat and melts when reaching its melting point. Further, the heat stored in the heat storage device 14 is thermally conducted to the radiator 16 and released to the outside through the fins 16a.

As a result, even if an overload current flows through the PTC element plate 11 for a long time and the PTC element plate 11 generates heat, this heat is sequentially converted into heat of fusion of the low melting point metal 14b. The plate 11 has a resistance transition temperature (Tc =
(200-240 ° C.). At this time, M
When an overload current of 1.25 to 10 times the rated current (In) continuously flows through the CCB 100 for a long time, as shown in FIG. 14, a predetermined time (10 Seconds to 120 minutes), the MCC
The tripping device of B100 is operated to release the switching mechanism and trip the main contact, and the load side is cut off from the power supply so that no overload current flows in the electric circuit.

On the other hand, when a short circuit accident occurs on the load side of the electric circuit and a short circuit current flows (short circuit area in FIG. 14), an excessive short circuit current flows through the PTC element plate 11 of the current limiter 10. The PTC element plate 11 by the Joule heat
Generates heat. Then, the heat generated causes the PTC element plate 11
Reaches the resistance transition temperature (Tc = 200 to 240 ° C.), the resistivity (ρ) of the PTC element plate 11 becomes the maximum value (ρma).
x), and the PTC element plate 11 starts the operation of suppressing (current limiting) the short-circuit current. Then, for 0.02 seconds (50H
Within one cycle in the case of z), the opening operation of the main contact of the MCCB 100 ends, the load side is cut off from the power supply, and no short-circuit current flows in the electric circuit.

As described above, in the first embodiment, the PTC element plate 11 is formed in a thin plate shape, and the mounting hole 12a connected to the electric path on the power supply side is formed on one surface of the thin PTC element plate 11. The terminal plate 12 provided with
Since the terminal plate 13 having the mounting hole 13a connected to the electric circuit on the load side is fixed to the other surface of the C element plate 11, the direction of conduction of the thin PTC element plate 11 is in the thickness direction. In a state where the rated current flows in a steady state, the current-carrying resistance is reduced and the power loss is reduced.

When an overload current equal to or higher than the rated current flows, the PTC element plate 11 generates heat due to the Joule heat, and the generated heat is conducted to the regenerator 14. Thus, even if an overload current flows through the PTC element plate 11 for a long time and the PTC element plate 11 generates heat, the heat is successively absorbed by the regenerator 14 and the heat absorbed by the regenerator 14 is radiated. Since the PTC element plate 11 is released from the body 16, the PTC element plate 11 can be prevented from reaching the resistance transition temperature (Tc).

On the other hand, when a short-circuit current flows in the electric circuit, P
The TC element plate 11 generates heat by Joule heat caused by the short-circuit current. Then, the PTC element plate 11 reaches the resistance transition temperature, the resistance value of the PTC element plate 11 increases rapidly, and the short-circuit current is suppressed (current limiting), and the short-circuit current decreases. For this reason, by connecting the PTC element plate 11 to the MCCB 100 (see FIG. 4), the breaking capacity of the MCCB 100 is increased, so that even if a small capacity MCCB 100 is used, the same blocking effect as when using the large capacity MCCB 100 is used. Can be achieved, and the installation cost of the circuit breaker can be significantly reduced.

The regenerator 14 may be made of a metal having a large heat capacity, such as copper, tin, or lead. in this case,
The configuration of the heat storage device 14 is simplified, and the heat storage device 14 can be manufactured at low cost.

In the first embodiment described above, P
The two terminal plates 12 and 13 are connected to the upper and lower surfaces of the TC element plate 11, and a regenerator 14 for absorbing heat when the PTC element plate 11 generates heat is closely attached to the upper terminal plate 12 above the upper terminal plate 12. An example has been described in which a structure is adopted in which a radiator 16 is disposed above the regenerator 14 via an insulating plate 15 while being connected. However, the current limiter of the present invention has a structure other than that of the first embodiment described above. Also, various structures can be adopted. Hereinafter, various modifications of the current limiter of the first embodiment will be described.

Modification 1 FIG. 5 is a perspective view schematically showing a first modification of the current limiting device using the PTC element of the present invention. PTC of the first modification of FIG.
The current limiter 20 using the element has an upper terminal plate 22 made of a heat storage material, which is also used as a heat storage device, is fixed to the upper portion of the PTC element plate 21 by bonding, brazing or welding with a conductive adhesive. A lower terminal plate 23 also serving as a heat storage unit having the same configuration as that of the lower terminal 22 is fixed to the lower part of the PTC element plate 21 by bonding, brazing, or welding with a conductive adhesive.

Each of the terminal plates 22 and 23 also serving as a heat storage unit is provided in a metal container such as copper, aluminum or stainless steel having good conductivity and good heat conductivity in a low melting point metal (for example, as in the first embodiment described above). , Lead-tin alloy or solder etc.)
To form a hermetic seal. The terminal plates 22 and 23 also serving as regenerators are formed so as to extend from the PTC element plate 21, respectively.
At each end of 23, mounting holes 22a and 23a are provided.

A radiator 25 having a large number of radiating fins 25a is fixed to an upper portion of the upper terminal plate 22 also serving as a heat storage unit via an insulating plate 24 having good heat resistance. The radiator 2
Numeral 5 is made of an aluminum alloy having good thermal conductivity, and the upper terminal plate 22 also serving as a heat storage unit and the insulating plate 24, and the insulating plate 24 and the radiator 25 are integrally fixed by an adhesive.

As described above, in the first modification, the upper terminal plate 22 or the lower terminal plate 23 also serving as a regenerator, which is filled with a low melting point metal and is hermetically formed, as in the first embodiment described above. Even if the terminal plate 12 and the regenerator 14 have the same volume as those formed separately, the current limiter can be formed by extending the PTC element plate 21 to form the terminal plates 22 and 23 also serving as regenerators. Since the entire thickness of the device 20 can be reduced, this type of current limiting device 2
0 can be formed small. In addition, since the terminal plates 22 and 23 also serving as heat storage units are fixed to both surfaces of the PTC element plate 21, the heat released from the heated PTC element plate 21 can be efficiently absorbed. In addition, the heat storage material terminal plates 22 and 23 made of a heat storage material may be made of a metal body having a large heat capacity made of copper, tin, lead or the like. In this case, the production of the terminal plates 22 and 23 also serving as a heat storage device is facilitated, and the production is possible at low cost.

Modification 2 FIG. 6 is a perspective view schematically showing a second modification of the current limiting device using the PTC element of the present invention. PTC of the second modification of FIG.
The current limiter 30 using the element has a large number of radiating fins 3
An upper terminal plate 32 also serving as a heat accumulator and a radiator, which is provided with a heat storage material provided with 2b, is fixed to the upper portion of the PTC element plate 31 by bonding, brazing or welding with a conductive adhesive, and is fixed to the lower portion of the PTC element plate 31. The lower terminal plate 33 is fixed by bonding using an electrically conductive adhesive, brazing or welding. The outer surface of the upper terminal plate 32, which is also used as a heat storage unit and a radiator, is coated with an insulating film made of a material having good heat dissipation.

The heat storage material and the upper terminal plate 32, which also serves as a heat radiator, are made of an aluminum alloy having good heat conductivity and good conductivity, and have a low melting point metal (for example, in the above embodiment). 1 (made of a lead-tin alloy or solder, etc.) to form a hermetic seal.
The lower terminal plate 33 is formed of a metal having good conductivity and good heat conductivity, such as copper, aluminum, and stainless steel. Further, mounting holes 32a, 33a are provided at the ends of the terminal plates 32, 33, respectively.

As described above, in the second modification, the upper end plate 32 is provided with a large number of heat dissipating fins 32b in the upper portion, and a low-melting point metal is filled in the inside thereof to form a sealed heat storage unit and a heat dissipating body. This makes it possible to obtain a current limiter 30 that is smaller than the first modification. In addition, the heat storage device made of heat storage material and the terminal plate 3 also serving as a heat radiator
2 may be made of a metal body having a large heat capacity, such as copper, tin, or lead. In this case, the terminal plate 22, which also serves as a heat storage device,
23 can be easily manufactured and can be manufactured at low cost.

Third Modification FIG. 7 is a perspective view schematically showing a third modification of the current limiting device using the PTC element of the present invention. PTC of the third modification of FIG.
The current limiting device 40 using the element is configured such that an upper terminal plate 42 made of a heat storage material and also serving as a heat storage device is fixed to the upper portion of the PTC element plate 41 by bonding, brazing or welding with a conductive adhesive, and the heat storage device is also used. The lower terminal plate 43 also serving as a regenerator having the same configuration as the upper terminal plate 42 of the PTC element plate 4
1 is fixed to the lower portion by bonding with a conductive adhesive, brazing or welding.

The upper terminal plate 42 also serving as a regenerator and the lower terminal plate 43 serving also as a regenerator have a low melting point metal (for example, copper, aluminum, stainless steel, etc.) having good conductivity and good heat conductivity. As in the first embodiment described above, a hermetic seal is formed by filling with a lead-tin alloy or solder. Further, mounting holes 42a, 43a are provided at the ends of the terminal plates 42, 43, respectively.

A radiator 46 having a large number of radiating fins 46a is fixed to the upper portion of the upper terminal plate 42 also serving as a regenerator via an insulating plate 44 having good heat resistance, and a lower terminal plate 43 also serving as a regenerator. A heat radiator 47 having a large number of radiating fins 47a is fixed to an upper portion thereof via an insulating plate 45 having good heat resistance. The radiators 46 and 47 are formed of an aluminum alloy having good thermal conductivity, and the upper terminal plate 42 and the insulating plate 44, the lower terminal plate 43 and the insulating plate 45, and the insulating plate 44 and the radiator 46, the insulating plate The radiator 45 and the radiator 47 are integrally fixed by an adhesive.

As described above, in the third modification,
Each terminal plate 42 also serving as a heat storage device is provided on both surfaces of the PTC element plate 41,
43, and these terminal plates 42, 43
Since the heat radiators 46 and 47 are fixed to the upper and lower portions of the PTC element plate 41, the heat released from the heated PTC element plate 41 can be efficiently absorbed, and the absorbed heat can be efficiently transmitted from the heat radiators 46 and 47. Be able to release.

Note that the upper terminal plate 42 and the lower terminal plate 43, which are also made of a heat storage material and also serve as a heat storage device, may be made of a metal body having a large heat capacity, such as copper, tin, or lead. In this case, the production of each of the terminal plates 42 and 43 also serving as a heat storage device becomes easy, and the production can be performed at low cost.

Modification 4 In Embodiment 1 and Modifications 1, 2, and 3 described above, for example, in Embodiment 1, PTC element plate 11, terminal plates 12, 13, heat storage unit 14, insulating plate 15, and heat radiation The body 16 is formed into a substantially prismatic body (only the terminal plates 12 and 13 protrude from the substantially prismatic body) as a whole of the current limiter 10 in the form of a square having substantially the same shape as the PTC element plate 11. Was explained, but in general, PTC
Since the element plate is manufactured in a circular shape, if the entire current limiter is formed in a substantially cylindrical shape, this type of current limiter can be manufactured at low cost and can be easily manufactured.

Therefore, in the fourth modification, the entire current limiter is formed in a substantially columnar shape by using a PTC element plate manufactured in a circular shape. FIG. 8 is a perspective view schematically showing a fourth modification of the current limiter using the PTC element of the present invention.
The current limiter 50 using the PTC element of the fourth modification of FIG.
Thin PTC element plate 51 having a circular planar shape
An upper terminal plate 52 made of a heat storage material formed in a circular shape and also serving as a heat storage device is fixed to the upper portion by bonding, brazing, or welding with a conductive adhesive. Further, a lower terminal plate 53 having a circular planar shape is fixed to a lower portion of a thin PTC element plate 51 having a circular planar shape by bonding, brazing, or welding with a conductive adhesive. .

Upper terminal plate 5 made of heat storage material and also serving as a heat storage device
Reference numeral 2 denotes a low-melting-point metal (for example, a lead-tin alloy or a solder as in the first embodiment described above) in a container made of a metal such as copper, aluminum, and stainless steel having good conductivity and good heat conductivity. ) To form a hermetic seal.
The lower terminal plate 53 is formed of a metal having good conductivity and good heat conductivity, such as copper, aluminum, and stainless steel. In addition, connection portions (not shown) are provided at the respective ends of the terminal plates 52 and 53.

A heat radiator 55 having a large number of radiating fins 55a and having a circular planar shape is provided on an upper portion of the upper terminal plate 52 also serving as a heat storage device. An insulating plate 54 having a circular shape with good heat resistance is provided. Is fixed through. The heat radiator 55 is formed of an aluminum alloy having good thermal conductivity, and the upper terminal plate 52 and the insulating plate 54, and the insulating plate 54 and the heat radiator 55 are integrally fixed by an adhesive. With this configuration, the current limiter 50 as a whole is formed in a substantially columnar body.

As described above, when the entire current limiter 50 is formed in a substantially columnar body, the PT having a circular planar shape is manufactured.
Since it becomes possible to use the C element plate without processing it, this type of current limiter can be manufactured at low cost and can be easily manufactured.

The upper terminal plate 52 also serving as a heat storage device made of a heat storage material may be made of a metal body having a large heat capacity, such as copper, tin, or lead. In this case, the production of the upper terminal plate 52 also serving as a heat storage device is facilitated, and the production can be performed at low cost.

When a current limiting device is formed by using a PTC element plate having a square or circular planar shape,
As shown in FIG. 9, the arrangement of each component can be variously modified. FIG. 9A shows an example of the arrangement shown in FIGS. 1 and 8. If the insulating plate 15 or 54 is omitted from the current limiter having the arrangement shown in FIGS. 1 and 8, the arrangement shown in FIG. It becomes a sink. Further, when another radiator 16 or 55 is further added to the lower part of the current limiter having the arrangement shown in FIG. 9A, a current limiter having the arrangement shown in FIG. 9C is obtained. Further, when the insulating plate 15 or 54 is omitted from the current limiter having the configuration shown in FIG. 9C, the current limiter has the configuration shown in FIG. 9D.

Embodiment 2 FIG. 10 is a perspective view schematically showing a current limiter using a PTC element according to a second embodiment of the present invention. The current limiter 60 using the PTC element of the second embodiment shown in FIG.
We use what we did. As the PTC element, a cristobalite-based cerax is preferable as in the first embodiment described above.

A semi-cylindrical outer terminal body 63 having a U-shaped cross section and having a protruding portion 63a in the longitudinal direction is fixed to the outer surface of the semi-cylindrical PTC element body 61 by bonding, brazing or welding with an adhesive. Then, the PTC element body 61 and the outer terminal body 63 are electrically connected. The outer terminal body 63 is made of copper,
It is made of a metal having good conductivity and good heat conductivity, such as aluminum and stainless steel. The projection 63a is provided with a mounting hole 63b.

An inner terminal body 62 made of a heat storage material and having a protruding portion 62a in the longitudinal direction and also serving as a heat storage device is fixed to the inner surface of the half-width cylindrical PTC element body 61 by bonding, brazing or welding with an adhesive. , PTC element body 61 and inner terminal body 62 also serving as a heat storage device are electrically and thermally connected.
The inner terminal body 62 also serving as a heat storage material made of a heat storage material is provided in a container made of a metal such as copper, aluminum, and stainless steel, which has good conductivity and good heat conductivity, in a low melting point metal (for example,
As in the first embodiment described above, a lead-tin alloy or a solder or the like is filled) to form a hermetic seal in a prismatic shape. The projection 62a is provided with a mounting hole 62b.

A radiator 65 having a plurality of radiating fins 65a is fixed to an upper portion of the inner terminal body 62 also serving as a heat storage unit via an insulating plate 64 having good heat resistance. In this case, the inner terminal body 62 also serving as a heat storage unit and the insulating plate 64 are fixed with an adhesive, and the insulating plate 64 and the radiator 65 are also fixed with an adhesive. The heat radiator 65 is formed of an aluminum alloy having good thermal conductivity.

In the current limiter 60 of the second embodiment, the half-width cylindrical PTC element body 61 is connected to the half-width cylindrical outer terminal body 63 and the prism-shaped inner terminal 62 which also serves as a regenerator. The direction of current supply to the PTC element 61 is PTC element 6
1 are perpendicular to the section. for that reason,
The current-carrying resistance of the PTC element body 61 can be reduced. Further, since the low-melting-point metal is hermetically sealed in the inner terminal body 62 also serving as a heat storage device, when the PTC element 61 generates heat, the low-melting-point metal filled in the inner terminal body 62 also serving as a heat storage device is used. Is melted, and the heat generated by the PTC element body 62 due to the heat of fusion is stored. Further, since the heat dissipating body 65 includes a large number of heat dissipating fins 65a, the heat absorbed by the inner terminal body 62 also serving as a heat accumulator is released more efficiently than the heat dissipating fin 65a.

The mounting holes 63 b, 63 of the three current limiting devices 60, 60, 60 of the second embodiment configured as described above.
b and 63b are the MCs described in the first embodiment.
Power supply side terminal 102 of CB (breaker) 100 (see FIG. 4)
X, 102Y, and 102Z, respectively, and screwed, and the mounting holes 62 of the three current limiters 60, 60, 60
b, 62b, and 62b are respectively attached to the electric wires X, Y, and Z on the power supply side and screwed, so that the electric wires X, Y, and Z on the power supply side and the MCCB (circuit breaker) 100
0, 60, and 60. Thereby, MCCB (breaker) 100 provided with current limiter 60 for each phase is connected to the electric circuit. The MCCB (circuit breaker) 100
Are the same as those in the first embodiment described above, and the description thereof is omitted.

As described above, in the second embodiment, the PTC element is formed in the shape of a half-width cylinder having a U-shaped cross section to form the half-width cylindrical PTC element body 61. The outer terminal body 63 having a U-shaped cross section and a half-angle cylindrical shape on the surface.
When the inner terminal body 62 made of a heat storage material and also serving as a heat storage material is fixed to the inner surface of the half-sized cylindrical PTC element body 61, Since the power is supplied, the current-carrying resistance is reduced and the power loss is reduced in a state where the rated current in the steady state flows.

The heat generated by the PTC element body 61 is conducted from the three surfaces of the inner terminal body 62 also serving as a heat accumulator, so that the heat of the heated PTC element body 61 can be efficiently absorbed. Becomes Therefore, the PTC element body 61
Even if an overload current in the overcurrent region flows for a long time and the PTC element body 61 generates heat, this heat is successively absorbed by the inner terminal body 62 also serving as a regenerator and the inner terminal body 62 also serving as a regenerator. Since the heat absorbed by the PTC element 61 is released from the heat radiator 65, the PTC element 61 can be prevented from reaching the resistance transition temperature even if an overload current in the overcurrent region flows through the PTC element 61.

On the other hand, when a short-circuit current flows through the PTC element 61 of the current limiter 60, the PTC element 61 generates heat due to the Joule heat. Then, when the PTC element 61 reaches the resistance transition temperature (Tc = 200 to 240 ° C.) due to this heat generation, the resistivity (ρ) of the PTC element 61 becomes the maximum value (ρm).
ax), and the PTC element 61 suppresses (limits current) the short-circuit current.

The inner terminal body 62 made of a heat storage material and also serving as a heat storage device may be made of a metal body having a large heat capacity, such as copper, tin, or lead. In this case, the manufacturing of the inner terminal body 62 also serving as a heat storage device is facilitated, and the manufacturing can be performed at low cost.

Third Embodiment FIG. 11 is a perspective view schematically showing a third embodiment of a current limiter using a PTC element of the present invention. The current limiting device 70 using the PTC element of the third embodiment shown in FIG. 11 uses a PTC element formed in a cylindrical shape to form a cylindrical PTC element body 71. As the PTC element, a cristobalite-based ceramic is preferable as in the first and second embodiments described above.

On the inner surface of the cylindrical PTC element 71, a cylindrical inner terminal 73 having a projection 73a in the longitudinal direction is provided.
Are fixed by bonding, brazing or welding with an adhesive, and the cylindrical PTC element body 71 and the cylindrical inner terminal body 73 are electrically connected. The inner terminal body 73 is made of copper,
A metal having good conductivity such as aluminum or stainless steel is formed in a columnar shape. The projection 73a is provided with a mounting hole 73b.

A cylindrical heat storage 72 made of a heat storage material is fixed to the outer surface of the cylindrical PTC element 71 by bonding, brazing or welding with an adhesive. The cylindrical heat accumulator 72 made of the heat accumulating material uses the same low melting point alloy as in the first embodiment described above.
It is filled and sealed in a container made of metal having good thermal conductivity and good conductivity such as stainless steel.

The outer surface of the cylindrical heat accumulator 72 is provided with a cylindrical heat radiator outer terminal 74 having a protruding portion 74b in the longitudinal direction and made of a material having good thermal conductivity, which is bonded and brazed with an adhesive. Or it is fixed by welding. A large number of radiating fins 74a are formed on the outer surface of the outer terminal body 74, which also serves as a cylindrical radiator. The projection 74b is provided with a mounting hole 74c. The outer terminal body 74 also serving as a cylindrical heat radiator is formed of an aluminum alloy having good thermal conductivity, and an outer surface thereof is covered with an insulator.

The mounting holes 73 b, 73 of the three current limiting devices 70, 70, 70 of the third embodiment having the above-described configuration are described.
b, 73b are the MCs described in the first embodiment.
Power supply side terminal 102 of CB (breaker) 100 (see FIG. 4)
X, 102Y, and 102Z, respectively, and screwed to fix the mounting holes 74 of the three current limiters 70, 70, 70.
By attaching the screws c, 74c, 74c to the electric wires X, Y, Z on the power supply side and screwing them, the electric wires X, Y, Z on the power supply side and the MCCB (breaker) 100
0, 70, 70. Thereby, MCCB (breaker) 100 provided with current limiter 70 for each phase is connected to the electric circuit. The MCCB (circuit breaker) 100
Are the same as those in the first embodiment described above, and the description thereof is omitted.

The current limiting device 70 according to the third embodiment having the above-described configuration has a cylindrical PTC element in which the PTC element is formed in a cylindrical shape.
A cylindrical inner terminal body 73 is fixed to the inner surface of the cylindrical PTC element body 71 and a cylindrical PT
Since the cylindrical regenerator 72 and the outer terminal body 73 also serving as a cylindrical heat radiator are fixed to the outer surface of the C element body 71, electricity is supplied radially to the cross section of the cylindrical PTC element body 71.
Therefore, in a state where the rated current flows in a steady state, the conduction resistance decreases and the power loss decreases.

Further, since the heat generated by the PTC element body 71 is conducted from the entire circumferential surface to the cylindrical regenerator 72 on the outside thereof, the heat of the heated PTC element body 71 can be efficiently absorbed. It becomes possible. Therefore, even if an overload current in the overcurrent region flows through the PTC element body 71 for a long time and the PTC element body 71 generates heat, this heat is successively absorbed by the cylindrical heat storage 72 and the cylindrical heat storage Since the heat absorbed by the PTC element 72 is radiated from the outer terminal body 74 having a plurality of radiating fins 74a on its outer surface and also serving as a cylindrical heat radiator, even if an overload current flows through the PTC element body 71, the PTC element body 71 can be prevented from reaching the resistance transition temperature.

On the other hand, when a short-circuit current flows through the PTC element 71 of the current limiter 70, the PTC element 71 generates heat due to the Joule heat. Then, when the PTC element 71 reaches the resistance transition temperature (Tc = 200 to 240 ° C.) due to this heat generation, the resistivity (ρ) of the PTC element 71 becomes the maximum value (ρm).
ax), and the PTC element body 71 suppresses (limits current) the short-circuit current.

The cylindrical regenerator 72 made of a heat storage material may be made of a metal having a large heat capacity, such as copper, tin, or lead. In this case, the manufacture of the cylindrical regenerator 72 is facilitated, and the manufacture is possible at low cost.

Fourth Embodiment FIG. 12 is a perspective view schematically showing a current limiter using a PTC element according to a fourth embodiment of the present invention. A current limiter 80 using the PTC element of the second embodiment shown in FIG.
Two TC element plates 81 and 82 are used. As the PTC element, a cristobalite-based cerax is preferable as in the first embodiment described above.

Each of the PTC element plates 81 and 82 has a protruding portion 83a in the longitudinal direction and a lower portion also serving as a regenerator made of a heat storage material having a protruding portion 83b protruding in a height direction in a triangular cross section in the center. Adhesion with an adhesive, brazing or welding is fixed to both inclined surfaces of the projecting portion 83b of the terminal body 83,
The PTC element bodies 81 and 82 and the lower terminal body 83 are electrically and thermally connected. The lower terminal body 83 also serving as a heat storage unit is provided with a low melting point metal (for example, a lead-tin alloy or a solder as in the first embodiment) in a container made of a metal such as copper, aluminum, and stainless steel. Filled and sealed. The projection 83a is provided with a mounting hole 83c.

A heat storage material provided with a protruding portion 84a in the longitudinal direction at the upper portion of the lower terminal body 83 to which the PTC element plates 81 and 82 are fixed, and a groove 84b having a triangular cross section in the center in the height direction. An upper terminal body 84 also serving as a regenerator is provided. With the PTC element plates 81 and 82 interposed between both inclined surfaces of the groove portion 84b having a triangular cross section of the upper terminal body 84, the lower terminal body 83 and the upper terminal body 84 are bonded, brazed or welded with an adhesive. The upper terminal body 84 and the lower terminal body 83 are electrically and thermally connected. Upper terminal body 8 made of this heat storage material and also serving as a heat storage device.
In a container 4 made of a metal such as copper, aluminum or stainless steel having good conductivity and good heat conductivity, a low-melting point metal (for example, a lead-tin alloy or a solder ) Is sealed.
The projection 84a is provided with a mounting hole 84c.

After the lower terminal body 83 and the upper terminal body 84 are fixed, the periphery thereof is covered with an insulating sheet (not shown) having good heat resistance with an adhesive. A heat dissipator 85 having a plurality of heat dissipating fins 85a is fixed to the upper part of the upper terminal 84 also serving as a heat accumulator, which is covered with an insulating sheet, with an adhesive. The radiator 85 is made of an aluminum alloy having good thermal conductivity.

The current limiter 80 of the fourth embodiment is a heat accumulator made of a heat accumulator made of a plate-shaped PTC element plate 81, 82 and a projection 82b having a triangular cross section in the height direction at the center. An upper terminal also serving as a heat storage device, which is fixed to both surfaces of the inclined surface of the projecting portion 83b of the lower terminal body 83, and has a groove portion 84b having a triangular cross section in the center in the center thereof. A body 84 is provided, and these two terminal bodies 8 are provided.
3 and 84 are integrally fixed, so that the PTC element plate 8
1, 82 is the thickness direction.

Therefore, it is possible to reduce the conduction resistance of the PTC element plates 81 and 82 when the area of the plane of the current limiter 80 is constant. Further, since the low-melting-point metal is hermetically sealed in the interior of both terminal bodies 83 and 84, when the PTC element plates 81 and 82 generate heat, the two terminal bodies 83 and 84 also function as heat storage units. The low-melting point metal filled in the PTC melts, and the heat of fusion causes the PTC to melt.
The element plates 81 and 82 store the generated heat.
Further, since the heat dissipating body 85 has a large number of heat dissipating fins 85a, the heat absorbed by the upper terminal body 84, which also serves as a heat accumulator, is released more efficiently than the heat dissipating fins 85a.

The mounting holes 84c, 84 of the three current limiting devices 80, 80, 80 according to the fourth embodiment having the above-described configuration are provided.
c and 84c are the MCs described in the first embodiment.
Power supply side terminal 102 of CB (breaker) 100 (see FIG. 4)
X, 102Y, and 102Z, respectively, and screwed to fix the mounting holes 83 of the three current limiters 80, 80, 80.
c, 83c, and 83c are respectively attached to the electric wires X, Y, and Z on the power supply side and screwed, so that the electric wires X, Y, and Z on the power supply side and the MCCB (breaker) 100 are connected to the respective current limiters 8.
0,80,80. Thereby, MCCB (breaker) 100 provided with current limiter 80 for each phase is connected to the electric circuit. The MCCB (circuit breaker) 100
Are the same as those in the first embodiment described above, and the description thereof is omitted.

Modification In the above-described fourth embodiment, an example has been described in which one projection 83b is provided on the lower terminal 83 and one groove 84b that fits into the projection 83b is provided on the upper terminal 84. However, a plurality of protrusions and grooves may be provided. This modification is characterized in that two projections and two grooves are provided as shown in FIG.

FIG. 13 is a perspective view schematically showing a modification of the fourth embodiment. A current limiting device 90 using the PTC element of the modification of FIG. 13 is a PTC element plate 91, 92,
93 and 94 are used. As the PTC element, a cristobalite-based cerax is preferable as in the first embodiment described above.

The PTC element plates 91, 92, 93, 94
The projections 95b, 95c of the lower terminal body 95 also serving as a heat storage device, which is provided with a projection 95a in the longitudinal direction and has two projections 95b, 95c projecting into a triangular cross section in the height direction. Are fixed to both inclined surfaces by bonding, brazing, or welding with an adhesive, and each of the PTC element plates 91, 92, 93, 94 and the lower terminal body 95 are electrically and thermally connected. . The lower terminal body 95 also serving as a heat storage unit is provided with a low-melting-point metal (for example, made of a lead-tin alloy or a solder as in the first embodiment) in a container made of a metal such as copper, aluminum, and stainless steel. Filled and sealed. The projection 95a is provided with a mounting hole 95d.

The PTC element plates 91, 92, 93, 94
An upper terminal body also serving as a heat accumulator, comprising a heat storage material provided with a protrusion 96a in the longitudinal direction and formed with two grooves 96b and 96c having a triangular cross section in the height direction, on the upper part of the lower terminal body 95 to which is fixed. 96 are provided. This upper terminal body 96
The lower terminal body 95 and the upper terminal body 96 are bonded by an adhesive with the PTC element plates 91, 92, 93, 94 interposed between the respective inclined surfaces of the two grooves 96b, 96c having a triangular cross section. The upper terminal body 95 and the lower terminal body 96 are electrically and thermally connected. The upper terminal body 96 made of a heat storage material, which also serves as a heat storage device, is provided in a container made of a metal such as copper, aluminum, and stainless steel having good conductivity and good heat conductivity (for example, the first embodiment described above). (Made of lead-tin alloy or solder, etc.) in the same manner as described above. The projection 96a is provided with a mounting hole 96d.

After the lower terminal body 95 and the upper terminal body 96 are fixed, the periphery thereof is covered with an insulating sheet (not shown) having good heat resistance with an adhesive. A heat radiator 97 having a plurality of heat radiating fins 97a is fixed to an upper portion of the upper terminal body 96 also serving as a heat accumulator, which is covered with an insulating sheet, with an adhesive. The heat radiator 97 is formed of an aluminum alloy having good thermal conductivity.

In the current limiting device 90 of the present modification, as in the fourth embodiment, the direction of conduction of the PTC element plates 91, 92, 93, 94 is the thickness direction. Therefore, when the area of the plane of the current limiter 90 is constant, the PTC element plates 91, 92,
It is possible to further reduce the current-carrying resistance generated in 93 and 94.

The three current limiting devices 90, 90, 90 of the present modified example thus configured have the mounting holes 96d, 96d, 96 respectively.
d is the power supply side terminals 102X, 10 of the MCCB (circuit breaker) 100 (see FIG. 4) described in the first embodiment.
2Y and 102Z, respectively, and screwed, and mounting holes 95d, 95 of three current limiting devices 90, 90, 90
d and 95d are respectively attached to the electric wires X, Y and Z on the power supply side and screwed, so that the electric wires X, Y and Z on the power supply side are attached.
And the MCCB (breaker) 100 are each of the current limiters 90, 90,
90. Thereby, MCCB (breaker) 100 provided with current limiter 90 for each phase is connected to the electric circuit. The operation of the MCCB (circuit breaker) 100 is the same as that of the above-described first embodiment, and a description thereof will be omitted.

As described above, in the present embodiment and its modifications, the PTC element plate 8
1, 82 (or 91, 92, 93, 94), these PTC element plates 81, 82 (or 91, 92, 93, 94) are connected to both terminal plates 83, 84 (or 95, 96), current is supplied in the thickness direction of each PTC element plate, and when a rated current flows in a steady state, the current-carrying resistance is reduced and power loss is reduced.

On the other hand, when a short-circuit current flows through current limiter 80 (or 90), the PTC element plate 8
1, 82 (or 91, 92, 93, 94) generates heat. Then, the PTC element plates 81, 82 are generated by this heat generation.
(Or 91, 92, 93, 94) is the resistance transition temperature (T
c = 200-240 ° C.), the PTC element 81
Has a maximum value (ρmax), and the PTC element plates 81 and 82 (or 91, 92, 93 and 94) suppress (short-circuit) the short-circuit current.

The PTC element plates 81 and 82 (or 9
1, 92, 93, and 94) conduct heat from the two terminals 83 and 84 (or 95 and 96) which also serve as heat accumulators, so that the heat of the heated PTC element 81 can be efficiently absorbed. It is possible to do. Therefore, the overload current in the overcurrent region flows through the PTC element plates 81, 82 (or 91, 92, 93, 94) for a long time, and
TC element plates 81, 82 (or 91, 92, 93, 9)
Even if 4) generates heat, this heat is successively absorbed by the two terminals 83 and 84 (or 95 and 96) also serving as a heat storage device and is also absorbed by the upper terminal member 84 (or 96) also serving as a heat storage device. Since heat is released from the radiator 85 (or 97), the PTC element plates 81, 82 (or 91, 92, 9) are used.
3 and 94), the PTC element plates 81 and 82 (or 91, 92, 93 and 9) even if an overload current in the overcurrent region flows.
4) can be prevented from reaching the resistance transition temperature.

The two terminals 83 and 84 (or 95 and 96) which are also used as a heat storage device made of a heat storage material may be made of a metal material having a large heat capacity such as copper, tin or lead. In this case, the two terminals 83 and 84 (or 95,
96) can be easily manufactured and can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a current limiter using a PTC element according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a heat storage device of FIG.

FIG. 3 is a diagram showing an example of a temperature-resistivity characteristic of a PTC element used in the present invention.

FIG. 4 is a front view showing the outer shape of the circuit breaker of the present invention.

FIG. 5 is a perspective view schematically showing a first modification of the current limiter using the PTC element according to the first embodiment of the present invention.

FIG. 6 is a perspective view schematically showing a second modification of the current limiter using the PTC element according to the first embodiment of the present invention.

FIG. 7 is a perspective view schematically showing a third modification of the current limiter using the PTC element according to the first embodiment of the present invention.

FIG. 8 is a perspective view schematically showing a fourth modification of the current limiter using the PTC element according to the first embodiment of the present invention.

FIG. 9 is a diagram showing a modification of the arrangement configuration of each component in FIGS. 1 and 8;

FIG. 10 is a perspective view schematically showing a current limiter using a PTC element according to a second embodiment of the present invention.

FIG. 11 is a perspective view schematically showing a current limiter using a PTC element according to a third embodiment of the present invention.

FIG. 12 is a perspective view schematically showing a current limiter using a PTC element according to a fourth embodiment of the present invention.

FIG. 13 is a perspective view schematically showing a modification of the current limiter using the PTC element according to the fourth embodiment of the present invention.

FIG. 14 is a diagram showing operating characteristics of an MCCB (circuit breaker).

FIG. 15 is a diagram showing an example of a conventional current limiting device.

[Explanation of symbols]

10: current limiter, 11: PTC element plate, 12: upper terminal plate, 13: lower terminal plate, 14: heat storage device, 16: heat dissipator,
Reference numeral 20: current limiter, 21: PTC element plate, 22: upper terminal plate also serving as a heat storage device, 23: lower terminal plate, 25: radiator, 30
... current limiter, 31 ... PTC element plate, 32 ... upper terminal plate also used as heat storage and radiator, 33 ... lower terminal plate, 40 ... current limiter, 41 ... PTC element plate, 42 ... upper terminal used also as heat storage Plate, 43: Lower terminal plate also serving as a heat storage device, 46, 47: Heat radiator, 50: Current limiting device, 51: PTC element plate, 52: Upper terminal plate also serving as a heat storage device, 53: Lower terminal plate, 55: Heat dissipation body,
Reference numeral 60: current limiter, 61: PTC element body having a half-width cylindrical shape, 62:
Inner terminal body also serving as heat storage unit, 63 ... Semicircular cylindrical outer terminal body, 65 ... Heat radiator, 70 ... Current limiter, 71 ... Cylindrical PTC
Element body, 72: cylindrical heat storage device, 73: cylindrical inner terminal body, 74: outer terminal body also serving as a cylindrical radiator, 80: current limiter, 81, 82: PTC element plate, 83: also serving as a heat storage device Lower terminal body, 84: upper terminal body also serving as a heat storage device, 85: radiator, 90: current limiter, 91, 92, 93, 94: PTC element plate, 95: lower terminal body also serving as a heat storage device, 96 ... Upper terminal body also serving as a heat storage unit, 97. Heat radiator, 100. MCCB (circuit breaker), 101. Operation switch, 102X, 102Y,
102Z: Power supply side terminal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02H 9/02 H02H 9/02 B

Claims (16)

[Claims] 1. A PTC element having a positive temperature coefficient of resistance, whose resistance value increases rapidly when a predetermined resistance transition temperature is reached, is provided in an electric circuit, and an overcurrent such as a short-circuit current flows through the electric circuit, thereby causing the PTC element to have a high resistance. A current limiter using a PTC element that suppresses an overcurrent by rapidly increasing the resistance value when the temperature of the element rises and the temperature reaches the predetermined resistance transition temperature, wherein the PTC element has a thin plate shape. A thin PTC element plate, one end of which is connected to the power supply side of the electric circuit, and the other end of which is connected to the load side of the electric circuit; and A regenerator made of a heat storage material that is disposed in contact with the plate and absorbs heat generated in the thin plate-shaped PTC element plate and stores the heat; and a regenerator that is disposed in contact with the regenerator and stores heat in the regenerator. Radiator made of good heat conductive material that radiates heat And a current limiting device using a PTC element. 2. A thin plate-like PTC element plate having a terminal plate having one end connected to a power supply side of the electric circuit on one surface, and one end formed on the other surface of the thin PTC element plate with the electric circuit. 2. A current limiter using a PTC element according to claim 1, further comprising a terminal plate connected to the load side of the PTC element. 3. The heat storage device according to claim 1, wherein the low-melting point metal filled in a metal container is hermetically sealed, and the radiator includes a plurality of radiating fins. A current limiter using the PTC element according to claim 1. 4. The terminal plate and the heat storage device are integrally formed to form a terminal plate also serving as a heat storage device, and the integrally formed terminal plate also serving as a heat storage device is connected to the thin plate-shaped PTC element plate. 4. A current limiting device using a PTC element according to claim 2, wherein the current limiting device is connected to both surfaces of the current limiting device. 5. The terminal plate, the heat accumulator, and the heat radiator are integrally formed to form a terminal plate which also serves as a heat accumulator and a heat radiator, and the integrally formed heat accumulator and heat radiator are also used. 4. A current limiting device using a PTC element according to claim 2, wherein said terminal plate is connected to at least one surface of said thin PTC element plate. 6. The thin PTC element plate, the terminal plate,
6. The current limiter according to claim 2, wherein each of the heat accumulator and the heat radiator is formed so that each planar shape thereof is the same square shape, and the entire current limiting device is formed in a substantially prismatic shape. A current limiter using the PTC element according to any one of the above. 7. The thin PTC element plate, the terminal plate,
3. The current limiting device according to claim 2, wherein each of the heat accumulator and the heat radiator is formed to have a circular shape having the same diameter, and the entire current limiting device is formed in a substantially columnar shape.
A current limiter using the PTC element according to any one of claims 1 to 5. 8. A PTC element having a positive temperature coefficient of resistance, whose resistance value rapidly increases when a predetermined resistance transition temperature is reached, is provided in an electric circuit, and an overcurrent such as a short-circuit current flows through the electric circuit to cause the PTC element to have a positive temperature coefficient. A current limiter using a PTC element that suppresses an overcurrent by rapidly increasing the resistance value when the temperature of the element rises and the temperature reaches the predetermined resistance transition temperature. A half-width cylindrical PTC element body is formed into a half-width cylindrical PTC element body, and is tightly fixed to an outer surface of the half-width cylindrical PTC element body and is electrically connected to the same half-width cylindrical PTC element body. A semi-cylindrical outer terminal body having a U-shaped cross section provided with a protruding portion in a longitudinal direction, and an outer terminal body tightly fixed to an inner surface of the semi-cylindrical cylindrical PTC element body and electrically connected to the semi-circular cylindrical PTC element body Occurred on the same half-width cylindrical PTC element body An inner terminal body also serving as a heat accumulator, which is made of a heat accumulator and has a protruding portion in the longitudinal direction for absorbing heat and storing the heat; A current limiter using a PTC element, comprising: a heat radiator made of a good heat conductive material that radiates heat stored in the terminal body. 9. One of the outer terminal body and the protruding portion of the regenerator / inner terminal is connected to a power supply side of the electric circuit, and the other is connected to a load side of the electric circuit. 9. The device according to claim 8, wherein the inner terminal body serving also as a container is configured by hermetically sealing a low melting point metal filled in a metal container, and the heat radiator is provided with a large number of heat radiation fins. Current limiter using PTC element. 10. A PTC element having a positive temperature coefficient of resistance, whose resistance value rapidly increases when a predetermined resistance transition temperature is reached, is provided in an electric circuit, and an overcurrent such as a short-circuit current flows through the electric circuit to cause the PTC element to have a positive resistance temperature coefficient. A current limiter using a PTC element that suppresses an overcurrent by rapidly increasing the resistance value when the temperature of the element rises and the temperature reaches the predetermined resistance transition temperature, wherein the PTC element has a cylindrical shape. A cylindrical PTC element body, which is tightly fixed to the inner surface of the cylindrical PTC element body, is electrically connected to the cylindrical PTC element body, and has a protruding portion in the longitudinal direction thereof. A columnar inner terminal body; a cylindrical PTC element which is tightly fixed to an outer surface of the cylindrical PTC element body and is electrically connected to the cylindrical PTC element body;
A cylindrical heat accumulator made of a heat storage material that absorbs heat generated in the C element body and stores the heat; a cylindrical heat accumulator tightly fixed to the cylindrical heat accumulator and electrically connected to the cylindrical heat accumulator; Current limiter using a PTC element characterized by comprising a cylindrical heat radiator and an outer terminal body which is made of a good heat conductive material and has a protrusion in a longitudinal direction of the heat radiator. vessel. 11. One of the outer terminal body serving also as the cylindrical heat radiator and the protruding portion of the cylindrical inner terminal body is connected to the power supply side of the electric circuit, and the other is connected to the load side of the electric circuit. In addition, the cylindrical regenerator is configured by hermetically sealing a low melting point metal filled in a metal container, and has a large number of radiating fins on an outer surface of the outer terminal body also serving as the cylindrical radiator. 2. The method according to claim 1, wherein
0. A current limiting device using the PTC element described in 0. 12. A PTC element having a positive temperature coefficient of resistance, whose resistance value rapidly increases when a predetermined resistance transition temperature is reached, is provided in an electric circuit, and an overcurrent such as a short-circuit current flows through the electric circuit to cause the PTC element to have a positive resistance temperature coefficient. A current limiter using a PTC element that suppresses an overcurrent by rapidly increasing the resistance value when the temperature of the element rises and the temperature reaches the predetermined resistance transition temperature, wherein the PTC element has a plate shape. To form a plurality of PTC element plates, each of which has a protrusion in the longitudinal direction and at least one protrusion having a triangular cross section in the height direction to absorb heat generated in the PTC element plate. A lower terminal body made of a heat storage material for storing heat, and having at least one groove having a triangular cross section in the height direction, the groove having a protrusion in the longitudinal direction thereof and being fitted to the protrusion of the lower terminal. The PTC An upper terminal body made of a heat storage material that absorbs heat generated in the element plate and stores the heat, and a good heat conductive material that is disposed above the upper terminal body and radiates heat stored in the upper terminal body. A heat radiator, between the inclined surface of the triangular cross-sectional projection of the lower terminal body and the inclined surface of the triangular cross-sectional groove of the upper terminal body fitted to the triangular cross-sectional projection. A current limiter using a PTC element, wherein the PTC element plate is narrowly attached. 13. One of the protruding portions of the upper terminal body and the lower terminal body is connected to a power supply side of the electric circuit, and the other is connected to a load side of the electric circuit. The body and the lower terminal body are configured by hermetically sealing a low melting point metal filled in a metal container, and provided with a large number of radiating fins on an outer surface of the radiator. 13. A current limiter using the PTC element according to 12. 14. The CTC element according to claim 1, wherein the PTC element is a cristobalite-based ceramic having a small room temperature resistivity and a large resistance increase with respect to the room temperature resistivity.
A current limiter using the PTC element according to any one of claims 1 to 13. 15. When an overcurrent such as a short-circuit current flows through an electric circuit, the temperature rises, and when the temperature reaches a predetermined resistance transition temperature, the resistance value sharply increases to suppress the overcurrent.
PTC with current limiter using TC element connected to its power supply side
A circuit breaker provided with a current limiting device using an element, wherein when an overload current exceeding a rated current flows through the electric circuit, the PTC element is prevented from reaching the resistance transition temperature and a short-circuit current of When such an overcurrent flows, the PTC element reaches the resistance transition temperature to suppress the overcurrent, and the overcurrent or the overload current continuously flows in the electric circuit for a preset time. And a circuit breaker provided with a current limiter using a PTC element, wherein the overcurrent or the overload current is interrupted. 16. The current limiting device according to claim 15, wherein
A circuit breaker provided with a current limiter using a PTC element, which is the current limiter according to any one of claims 1 to 14.