JP2011222414A - Cutoff device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure that a current flowing between the positive and negative poles of a power supply and a load is cut off in the entire overcurrent range.SOLUTION: A cutoff device comprising a fuse, an opening/closing mechanism for opening/closing an electrical path at a connected position, and a movable iron piece which has one of its ends in contact with the opening/closing mechanism provided between a load whose power is fed from a power supply and the power supply. In the cutoff device, the opening/closing mechanism opens the electrical path as the other end of the movable iron piece moves from a first position to a second position according to a magnetic force whose magnitude corresponding to a current flowing in the opening/closing mechanism. The fuse is connected between at least one of the two poles of the power supply and the load, the opening/closing mechanism is connected between one of the two poles of the power supply which does not at least have the fuse connected and the load, and the movable ion piece has the other end thereof moved from the first position to the second position by application of a force of mechanical energy to the movable iron piece generated in conjunction with the blowout of the fuse.

Description

  The present invention relates to a breaker that protects a circuit when an overcurrent accident or a short-circuit accident occurs.

  The power supply circuit that supplies power to the load from the DC power supply is provided with a shut-off device to cut off the current flowing between the positive and negative poles of the DC power supply and the load in the event of an overcurrent or short-circuit accident. Yes.

  FIG. 5 is a diagram for explaining an example of the blocking device.

  In the example shown in FIG. 5, fuses 100 a and 100 b are connected between the positive and negative electrodes of the DC power supply 2 and the load 3. When an overcurrent accident or a short-circuit accident occurs in the load, the fuses 100a and 100b are blown, so that the current flowing between the positive and negative electrodes of the DC power supply 2 and the load is interrupted.

  FIG. 6 is a diagram for explaining another example of the blocking device.

  In the case of the example shown in FIG. 6, a circuit breaker 110 is provided between the positive and negative electrodes of the DC power supply 2 and the load 3. When an overcurrent accident or a short-circuit accident occurs in the load 3, the open / close mechanisms 110 a and 110 b of the circuit breaker 110 are linked to open the electric circuit, so that the current flows between the positive and negative poles of the DC power supply 2 and the load 3. The current is cut off.

  FIG. 7 is a diagram for explaining another example of the blocking device.

  The example shown in FIG. 7 is a blocking device that combines the two examples described above. That is, fuses 100 a and 100 b and a circuit breaker 110 are provided between the positive and negative electrodes of the DC power supply 2 and the load 3.

Japanese Patent No. 3091712 Japanese Patent No. 2513350 Japanese Patent No. 2998934

  In the breaking device using the fuses 100a and 100b shown in FIG. 5, the two fuses 100a and 100b are connected in series in the same closed circuit. For this reason, when an overcurrent accident or a short circuit accident occurs in the load 3, the same current flows through the fuses 100a and 100b. Therefore, theoretically, the fuses 100a and 100b are blown simultaneously.

  However, in reality, the fuses 100a and 100b have individual differences in the fusing characteristics, and therefore only one of the fuses 100a and 100b may be blown. In this case, the load 3 is disconnected from the DC power supply 2 at the pole where the fuse is blown. However, the load 3 remains connected to the DC power source 2 at the pole that has not melted. In other words, current interruption between the positive and negative electrodes of the DC power supply 2 and the load 3 is not guaranteed.

  Therefore, if there is a potential difference between the unfused pole and the ground, there is a problem in that there is a risk of electric shock when the human body touches the charged part.

  Further, in the circuit breaker using the circuit breaker 110 shown in FIG. 6, since the open / close mechanisms 110a and 110b open the electric circuit in conjunction with each other, the current flowing between the positive and negative electrodes of the DC power source 2 and the load 3 is simultaneously interrupted. Is possible.

  However, even if the circuit breaker 110 is within the range of the breaking capacity of the circuit breaker 110, the circuit breaker 110 will be used after the next time if the rated current value is greatly exceeded and the switching mechanism 110a, 110b is interrupted by a large current that is damaged by an arc. There is a problem that a guarantee cannot be secured.

  Further, in the breaking device using the fuses 100a and 100b and the circuit breaker 110 shown in FIG. Depending on how to combine with the breaking characteristics of the circuit breaker 110, the shorter of the breaking times of the fuses 100a and 100b and the circuit breaker 110 cuts off the current.

  FIG. 8 is a diagram showing an example of the relationship between the current value and the interruption time in the interruption device shown in FIG.

  As shown in FIG. 8, in the overcurrent range exceeding the rated current value, in the range where the current value is small, the circuit breaker 110 has a cutoff time shorter than that of the fuses 100a and 100b. Cut off. Moreover, since the interruption time of the fuses 100a and 100b is set shorter than that of the circuit breaker 110 in the range where the current value is large, the fuses 100a and 100b interrupt the current.

  At this time, if the intersection between the fusing characteristics of the fuses 100a and 100b and the breaking characteristic of the circuit breaker 110 is set to be equal to or less than a specified current value that guarantees the repeated use of the circuit breaker 110, the current range in which the repeated use of the circuit breaker 110 is not guaranteed. This current is interrupted by the fuses 100a and 100b.

  Therefore, since the fuses 100a and 100b cut off the current exceeding the specified current value that guarantees repeated use of the circuit breaker 110, the switching mechanisms 110a and 110b are not damaged. In the current range where the circuit breaker 110 cuts off the current, the circuit breaker 110 cuts off the current flowing between the positive and negative poles of the DC power supply 2 and the load 3 in an interlocking manner. The current between the two can be reliably interrupted.

  However, in the current range where the fuses 100a and 100b cut off the current, even if an overcurrent occurs, the circuit breaker 110 does not cut off the current, and the open / close mechanisms 110a and 110b remain closed.

  Therefore, as in the case of the interruption device shown in FIG. 5, the interruption of the current between the positive and negative poles of the DC power supply 2 and the load 3 is not guaranteed due to individual differences in the fusing characteristics of the fuses 100a and 100b.

  An object of this invention is to provide the interruption | blocking apparatus which makes it possible to interrupt | block reliably the electric current which flows between the positive / negative poles of a power supply, and load in all the overcurrent ranges.

In order to achieve the above object, a circuit breaker according to the present invention includes a fuse, an opening / closing mechanism that opens and closes an electric circuit at a connected position, and a movable iron piece having one end abutting against the opening / closing mechanism, and is supplied with power from a power source. As the other end of the movable iron piece is moved from the first position to the second position by a magnetic force corresponding to the current flowing through the opening / closing mechanism, the opening / closing mechanism is In the circuit breaker that opens the circuit,
The fuse is connected between at least one of the poles of the power source and the load;
The opening / closing mechanism is connected between at least the pole to which the fuse is not connected, and the load, of both poles of the power source,
The movable iron piece is moved from the first position to the second position when a force by mechanical energy generated in conjunction with the fusing of the fuse is applied to the movable iron piece.

  Since the present invention is configured as described above, the current flowing between the positive and negative poles of the power source and the load is cut off even in the current range where the fuse blows the current.

  Therefore, in all overcurrent ranges, it is possible to reliably cut off the current flowing between the positive and negative poles of the power supply and the load.

It is a figure which shows the structure of one Embodiment of the electric power feeding circuit to which the interruption | blocking apparatus of this invention is applied. It is a figure for demonstrating the operation | movement principle of the circuit breaker shown in FIG. 1, (a) is a figure which shows the state which the opening / closing mechanism does not open | release an electric circuit, (b) is the opening / closing mechanism opening the electric circuit. It is a figure which shows a state. It is a figure for demonstrating the structure of the interlocking | linkage part shown in FIG. It is a figure for demonstrating the operation | movement which the interlocking | linkage part shown in FIG.1 and FIG.3 moves the other end of a movable iron piece in response to interruption | blocking of a fuse. It is a figure for demonstrating an example of a cutoff device. It is a figure for demonstrating the other example of the interruption | blocking apparatus. It is a figure for demonstrating the other example of the interruption | blocking apparatus. It is a figure which shows an example of the relationship between the electric current and interruption | blocking time in the interruption | blocking apparatus shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of an embodiment of a power feeding circuit to which a blocking device of the present invention is applied.

  As shown in FIG. 1, the power supply circuit according to the present embodiment includes a cutoff device 1, a DC power supply 2, and a load 3.

  The circuit breaker 1 is provided between the DC power source 2 and the load 3, and includes a fuse unit 10 and a circuit breaker 20. In FIG. 1, the fuse portion 10 is provided between the positive electrode of the DC power supply 2 and the load 3 on the load 3 side of the circuit breaker 20. The position where the fuse unit 10 is provided is not limited to this, and may be between the negative electrode of the DC power supply 2 and the load 3, or may be closer to the DC power supply 2 than the circuit breaker 20.

  The circuit breaker 20 includes an opening / closing mechanism 21 and a movable iron piece 22.

  The switching mechanism 21 is connected between the positive electrode of the DC power source 2 and the load 3, connected to the negative electrode of the DC power source 2 and the load 3, and includes a movable contact 21-1 and a fixed contact 21-2. The current flowing between the DC power source 2 and the load 3 uses the movable contact 21-1 and the fixed contact 21-2 as an electric circuit, and the switching mechanism 21 separates the movable contact 21-1 and the fixed contact 21-2. To open the circuit. When the switching mechanism 21 opens the electric circuit, the current flowing between the positive electrode of the DC power source 2 and the load 3 or the current flowing between the negative electrode of the DC power source 2 and the load 3 is cut off.

  The movable iron piece 22 is provided corresponding to one opening / closing mechanism 21, and has one end abutting on the opening / closing mechanism 21 and the other end movable. Hereinafter, with respect to the movable iron piece 22, the one in contact with the opening / closing mechanism 21 is referred to as “one end of the movable iron piece 22”, and the movable one is referred to as “the other end of the movable iron piece 22”.

  2A and 2B are diagrams for explaining the operating principle of the circuit breaker 20 shown in FIG. 1. FIG. 2A is a view showing a state where the open / close mechanism 21 does not open the electric circuit, and FIG. It is a figure which shows the state which has open | released the electric circuit. In FIG. 2, only the components necessary for explanation are shown among the components of the circuit breaker 20.

  As shown in FIG. 2, the circuit breaker 20 shown in FIG. 1 includes a cylinder 23, a movable iron core 24, a spring 25, and a pole plate 26 in addition to the opening / closing mechanism 21 and the movable iron piece 22 described above. Corresponding to the opening / closing mechanism 21 is provided. A coil (not shown) is wound around the cylinder 23, and a current that flows between the positive electrode of the DC power source 2 and the load 3 or a current that flows between the negative electrode of the DC power source 2 and the load 3 is used. Passes through this coil via a movable contact 21-1 and a fixed contact 21-2.

  When the current flowing between the DC power source 2 and the load 3 is equal to or less than the rated current value, the other end of the movable iron piece 22 is located away from the electrode plate 26 as shown in FIG. Hereinafter, this position is referred to as a first position. The movable iron core 24 is located away from the electrode plate 26 by the spring 25. At this time, the opening / closing mechanism 21 does not open the electric circuit, and the current is not interrupted.

  When the current flowing between the DC power source 2 and the load 3 exceeds the rated current value, the movable iron core 24 starts moving in the direction of the electrode plate 26 by the magnetic force corresponding to the current flowing through the coil described above. To do. Then, when the movable iron core 24 reaches the electrode plate 26, the magnetic force increases rapidly, and the movable iron piece 22 is attracted to the electrode plate 26 as shown in FIG. Hereinafter, the position of the other end of the movable iron piece 22 when the movable iron piece 22 is attracted to the electrode plate 26 is referred to as a second position.

  As the other end of the movable iron piece 22 moves from the first position to the second position, the movable contact 21-1 and the fixed contact 21-2 are pulled apart. Thereby, the electric circuit is opened, and the current flowing between the positive electrode of the DC power supply 2 and the load 3 or the current flowing between the negative electrode of the DC power supply 2 and the load 3 is cut off.

  When a short circuit occurs, a current having a very large current value flows in the above-described coil, thereby generating a strong magnetic force. In this case, the movable iron piece 22 is instantaneously attracted to the electrode plate 26 without waiting for the movement of the movable iron core 24.

  As described above, the circuit breaker 20 of the present embodiment is similar to the conventionally used circuit breaker, as the other end of the movable iron piece 22 moves from the first position to the second position. Is a general circuit breaker that opens the circuit. However, in the present embodiment, the other end of the movable iron piece 22 is not moved from the first position to the second position by the magnetic force, but the other end of the movable iron piece 22 is moved by the operation in conjunction with the fuse portion 10. Move from the first position to the second position. Details of this operation will be described later.

  Referring to FIG. 1 again, the fuse part 10 includes a fuse 11 and an interlocking part 12.

  The fuse 11 is connected between the positive electrode of the DC power source 2 and the load 3 and is blown when the energy due to the current flowing between the positive electrode of the DC power source 2 and the load 3 reaches a predetermined fusing energy. As a result, the current flowing between the positive electrode of the DC power supply 2 and the load 3 is cut off.

  The interlocking unit 12 operates in conjunction with the interruption of the fuse 11 to move the other end of the movable iron piece 22-1 of the circuit breaker 20 from the first position to the second position.

  FIG. 3 is a diagram for explaining the configuration of the interlocking unit 12 shown in FIG. FIG. 3 shows a state where the other end of the movable iron piece 22 is not moved from the first position to the second position by the operation of the interlocking unit 12. Moreover, in FIG. 3, only the part required for description among the components of the interruption | blocking apparatus 1 is described.

  As shown in FIG. 3, the interlocking unit 12 shown in FIG. 1 includes a sub fuse 12-1, an elastic body 12-2 that is an energy conversion unit, and a fixing unit 12-3.

  The sub fuse 12-1 is connected in parallel with the fuse 11 between the positive electrode of the DC power supply 2 and the load 3. The sub fuse 12-1 is blown after the fuse 11 is blown. That is, the sub fuse 12-1 is blown in conjunction with the blow of the fuse 11. This can be realized by connecting a resistor (not shown) or the like in series with the sub-fuse 12-1 and adjusting the current flowing into the sub-fuse 12-1.

  The elastic body 12-2 is, for example, a plate spring having an original shape, and one end is fixed to the fixing portion 12-3 using the sub fuse 12-1, and the other end is fixed to the fixing portion 12-3. Directly fixed. Further, as shown in FIG. 3, the elastic body 12-2 is deformed into a shape different from the original plate shape and fixed to the fixing portion 12-3. Therefore, the elastic body 12-2 accumulates elastic energy which is a kind of potential energy in a state where the elastic body 12-2 is fixed to the fixing portion 12-3.

  The operation when an overcurrent accident or a short-circuit accident occurs in the load 3 in the power feeding circuit to which the interrupting device 1 configured as described above is applied will be described below.

  When an overcurrent accident or a short circuit accident occurs in the load 3, the current flowing between the positive electrode of the DC power source 2 and the load 3 increases. When the energy due to this current reaches a predetermined fusing energy, the fuse 11 is blown. As a result, the current flowing between the positive electrode of the DC power supply 2 and the load 3 is cut off.

  And the interlocking | linkage part 12 moves the other end of the movable iron piece 22 of the circuit breaker 20 from a 1st position to a 2nd position by operating in response to interruption | blocking of the fuse 11. FIG.

  FIG. 4 is a view for explaining an operation in which the interlocking portion 12 shown in FIGS. 1 and 3 moves the other end of the movable iron piece 22 in conjunction with the interruption of the fuse 11. In FIG. 4, only the parts necessary for the description are shown among the components of the blocking device 1.

  When the fuse 11 is blown, the current flowing between the positive electrode of the DC power source 2 and the load 3 flows into the sub fuse 12-1 side, and the sub fuse 12-1 is blown.

  When the sub fuse 12-1 is melted, one end of the elastic body 12-2 fixed using the sub fuse 12-1 is separated from the fixing portion 12-3. Thereby, the elastic body 12-2 returns to the original plate shape. That is, the elastic energy accumulated in the elastic body 12-2 due to the deformation of the elastic body 12-2 is converted into kinetic energy by the fusing of the sub fuse 12-1.

  Then, as shown in FIG. 4, the elastic body 12-2 that has returned to its original shape comes into contact with the movable iron piece 22, and the movable iron piece 22 is pushed out toward the electrode plate 26. This is the same movement as the movable iron piece 22 is attracted to the electrode plate 26, and the other end of the movable iron piece 22 moves from the first position to the second position.

  The elastic body 12-2 that has returned to the original plate shape includes a movable iron piece 22 corresponding to the opening / closing mechanism 21 connected between the positive electrode of the DC power source 2 and the load 3, and the negative electrode of the DC power source 2. Both the movable iron pieces 22 corresponding to the opening / closing mechanism 21 connected to the load 3 are brought into contact with each other, and the other ends of both the movable iron pieces 22 are moved from the first position to the second position.

  As a result, the movable contact 21-is connected to both the switching mechanism 21 connected between the positive electrode of the DC power source 2 and the load 3 and the switching mechanism 21 connected between the negative electrode of the DC power source 2 and the load 3. 1 and the fixed contact 21-2 are separated. That is, both the opening / closing mechanisms 21 open the electric circuit, and the current flowing between the positive and negative electrodes of the DC power supply 2 and the load 3 is interrupted.

  In the present embodiment, the configuration in which the switching mechanism 21 is connected between the positive and negative electrodes of the DC power source 2 and the load 3 has been described. Instead of such a configuration, the switching mechanism 21 may be connected only between the pole to which the fuse 11 is not connected and the load 3 among the two poles of the DC power supply 2. However, in this configuration, a circuit breaker having a cut-off time longer than the fusing time of the fuse 11 is used in all overcurrent ranges, or a circuit breaker that does not automatically start cutting off current due to overcurrent is used. It will be necessary. This is because if the circuit breaker performs a breaking operation before the fuse 11, the current flowing between the pole to which the fuse 11 is connected and the load 3 will not be cut off.

  Thus, in the present embodiment, the fuse 11 is connected between one of the two poles of the DC power supply 2 and the load 3, and the switching mechanism 21 is connected to at least the fuse 11 of the two poles of the DC power supply 2. It is connected between the pole that is not connected and the load 3. The movable iron piece 22 is moved from the first position to the second position by applying to the movable iron piece 22 a force by mechanical energy generated in conjunction with the fusing of the fuse 11.

  Therefore, even in the current range in which the fuse 11 blows the current, the current flowing between the positive and negative electrodes of the DC power supply 2 and the load 3 is cut off, and in both the overcurrent ranges, the positive and negative electrodes of the DC power supply 2 and the load 3 It is possible to reliably cut off the current flowing between the two.

  Further, in the present embodiment, since no current is used to link the fusing of the fuse 11 and the circuit breaker 20, there is no risk that the circuit or the like will burn out.

  In addition, in this embodiment, the structure which moves the other end of the movable iron piece 22 by the elastic body 12-2 contacting the movable iron piece 22 was demonstrated. Instead of such a configuration, the other end of the movable iron piece 22 may be moved via an interlocking mechanism that transmits kinetic energy due to the elastic body 12-2 returning to its original shape.

  In the present embodiment, the case where the interrupting device of the present invention is applied to the power feeding circuit that feeds power from the DC power source 2 to the load 3 has been described, but the present invention is not limited to this, and power is fed from the AC power source to the load. The present invention can also be applied to a power feeding circuit.

DESCRIPTION OF SYMBOLS 1 Circuit breaker 2 DC power supply 3 Load 10 Fuse part 11 Fuse 12 Interlocking part 12-1 Sub fuse 12-2 Elastic body 12-3 Fixed part 20 Circuit breaker 21 Opening and closing mechanism 21-1 Movable contact 21-2 Fixed contact 22 Movable iron piece 23 Cylinder 24 Movable iron core 25 Spring 26 Electrode plate

Claims (4)

A fuse, an open / close mechanism that opens and closes an electric circuit at a connected position, and a movable iron piece that is in contact with the open / close mechanism at one end, and is provided between a load fed from a power source and the power source; In the interrupting device in which the opening / closing mechanism opens the electric circuit as the other end of the movable iron piece moves from the first position to the second position with a magnetic force according to the current flowing through the mechanism,
The fuse is connected between at least one of the poles of the power source and the load;
The opening / closing mechanism is connected between at least the pole to which the fuse is not connected, and the load, of both poles of the power source,
The movable iron piece has a breaking device in which the other end moves from the first position to the second position when a force by mechanical energy generated in conjunction with the fusing of the fuse is applied to the movable iron piece. . The shut-off device according to claim 1,
Storing energy in a state where the fuse is not blown, and having an energy conversion unit that converts the stored potential energy into kinetic energy in conjunction with the melting of the fuse,
The movable iron piece is a blocking device in which the other end moves from the first position to the second position when a force by the kinetic energy is applied to the movable iron piece. The shut-off device according to claim 2,
The energy conversion unit is an elastic body that accumulates elastic energy by being deformed from the original shape,
The elastic body is fixed in a deformed state in a state where the fuse is not blown, and returns to its original shape in conjunction with the fusing of the fuse,
The movable iron piece is a blocking device in which the other end moves from the first position to the second position when the elastic body that has returned to its original shape comes into contact with the movable iron piece. The shut-off device according to claim 3,
A sub-fuse that is connected in parallel with the fuse and blows after the fuse is blown;
The elastic body is a breaker that is fixed in a deformed state using the sub-fuse in a state where the fuse is not blown, and returns to its original shape when the sub-fuse is blown.

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