Current breaker

Abstract

[Problem] To provide a current breaker with which it is possible to interrupt supply of electric power to an electric apparatus more quickly than before, and prevent electric leakage, electric shock, and the like more quickly than before. [Solution] A current breaker 100 comprises: an igniter 10, which is an example of a breaking force source; a cutting chamber 20 that has a top part 20c, a side part 20d, and a bottom part 20e and also has an accommodation space; a rod-form moving member 40 that can move in one direction within the cutting chamber 20; and a control unit 24 that drives the igniter 10 when an abnormality is detected. The igniter 10 includes: an ignition part 11 provided inside the igniter 10, the ignition part 11 including an ignition agent that generates flame by igniting and burning during operation, and a semiconductor bridge device that ignites the ignition agent; and a pair of terminal pins 12, 12 connected to the ignition part 11. The igniter 10 is held on the upper wall of the cutting chamber 20 so that the generated flame can be discharged toward the moving member 40 positioned below. The igniter 10 takes 300 μs or less from application of current to ignition of the ignition agent.

Description

Current interrupter

[0001] The present invention relates to a current interruption device that interrupts the supply of current to an electrical device.

[0002] For example, in the event of an accident or malfunction in an electric vehicle or the like, it is known to provide a current interruption device that interrupts the supply of power to electrical equipment in order to prevent leakage current and electric shock resulting from the accident or malfunction. For example, Patent Document 1 below discloses an electric circuit interruption device equipped with an igniter having a bridge wire (resistor) that connects the base ends of a pair of conductive pins, and an ignition charge that is contained in an igniter cup in contact with the bridge wire. Nichrome wire or the like is generally used for the bridge wire.

[0003] In the current interruption device disclosed in the above-mentioned Patent Document 1, when a predetermined current is applied to the bridge wire, the bridge wire reaches the ignition temperature of the ignition charge filled in the igniter cup, and the ignition charge ignites. This causes the igniter cup to break and be released, releasing a thrust force outside the igniter cup. The projectile that has gained this thrust cuts the bus bar of the current interrupter, thereby interrupting the current.

[0004] Japanese Patent Application Laid-Open No. 2023-59018

[0005] Igniters that use bridge wires such as nichrome wire take approximately 800 μs (microseconds) from the application of current to the ignition of the ignition charge, but there is a demand for current interruption devices that can more quickly cut off the supply of power to electrical equipment and more quickly prevent leakage and electric shock in the unlikely event of an accident or malfunction in an electric vehicle.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a current interruption device that can interrupt the supply of power to electrical equipment more quickly than conventional devices and prevent electrical leakage, electric shock, and the like more quickly than conventional devices.

[0007] (1) The current interruption device of the present invention is characterized by comprising: a housing having a top, a bottom, and a side and containing an internal storage space; an igniter provided on the top of the housing, the time from application of current to ignition of an ignition charge being 300 μs or less; a movable member disposed within the housing and movable within the storage space by energy received directly or indirectly from the activated igniter; and a current supply path that is a conductor that penetrates the side of the housing, is installed within the storage space, and forms part of an electric circuit, and can be cut off by the movable member that moves upon activation.

[0008] (2) From another viewpoint, the current interruption device according to the present invention may be characterized by comprising: a housing having a top portion, a bottom portion, and a side portion and containing an internal storage space; an ignition unit including an ignition charge and a semiconductor bridge device for igniting the ignition charge, an igniter provided on the top portion of the housing; a movable member disposed within the housing and movable within the storage space by energy received directly or indirectly from the activated igniter; and a current supply path that is a conductor that penetrates the side portion of the housing, is installed within the storage space, and forms part of an electric circuit, and can be cut off by the movable member that moves upon activation.

[0009] According to the present invention, it is possible to provide a current interruption device that can interrupt the supply of power to an electrical device more quickly than before and prevent leakage of electricity, electric shock, and the like more quickly than before.

[0010] 1 is a cross-sectional view showing a current interruption device according to an embodiment of the present invention;

[0023] FIG. 2 is a view showing a state in which the current supply path of FIG.

[0011] A current interruption device according to an embodiment of the present invention will now be described with reference to the drawings. The current interruption device according to the present embodiment is used, for example, in a vehicle (e.g., an electric vehicle using a large current) equipped with an electrical circuit having an electrical device and a current supply source that supplies current to the electrical device. When an abnormality such as an accident (collision) or a malfunction (one example of an abnormality in the external environment of the current interruption device according to the present embodiment) is detected in the vehicle, the device interrupts the current supply from the current supply source to the electrical device. Note that, in the present invention, the current supply source is not particularly limited, and examples include current supply sources that generate electricity from Li-ion batteries, Li-Po batteries, fuel cells, hydrogen fuel, gasoline, natural gas, sunlight, etc., or generators. Furthermore, in the present invention, a circuit abnormality refers to, for example, a short circuit, overcurrent, overvoltage, abnormal heat, or the like occurring in the circuit.

[0012] As shown in Figure 1, the current interruption device 100 of this embodiment includes an igniter 10, which is an example of a destructive force source (power source), a cutting chamber 20 (housing) having a top portion 20c, a side portion 20d, and a bottom portion 20e and having an accommodation space (internal space), a rod-shaped moving member 40 that can move in one direction (downward in Figure 1) within the cutting chamber 20, and a control unit 24 that drives the igniter 10 when an abnormality such as an accident (collision) or malfunction is detected in a vehicle or the like.

[0013] The igniter 10 generates a flame and includes an ignition unit 11 including an ignition charge (not shown) that is provided inside the igniter 10 and ignites and burns to generate a flame when activated, a semiconductor bridge device (not shown) for igniting the ignition charge, and a pair of terminal pins 12, 12 connected to the ignition unit 11. The igniter 10 is held on the upper wall of the cutting chamber 20 so that the generated flame (energy) can be emitted toward the moving member 40 located below. Note that the igniter 10 is preferably one that takes 300 μs or less (e.g., 50 μs to 300 μs) from the application of current to the ignition of the ignition charge; for example, an igniter such as that disclosed in Japanese Patent Publication No. 4746554 or Japanese Patent Publication No. 4848118 can be used.

[0014] The moving member 40 is a rod-shaped member having a pointed tip on the current supply path 30 side, and is made of an insulating material such as synthetic resin.

[0015] When an abnormality such as an accident (crash) or breakdown is detected in a vehicle or the like, a predetermined amount of current flows through the resistor via the pair of terminal pins 12, 12 under the control of the control unit 24. The current flowing through the semiconductor bridge device generates a high-temperature spark with a high power density (for example, higher than 4000 degrees Kelvin in some cases) sufficient to ignite the ignition charge, causing the ignition charge to begin burning. The high-temperature flame produced by the combustion explodes a squib cup (not shown) containing the ignition charge.

[0016] A through hole 20a is provided in the side wall of the cutting chamber 20, and a through hole 20b is provided in another portion of the side wall (in this embodiment, a portion facing the through hole 20a). A current supply path 30 is bridged through these through holes 20a and 20b. The current supply path 30 is a conductor (bus bar) such as a copper plate, and a pair of terminal plates 21 are provided at one end and the other end of the bus bar. Terminals 22 are connected to the pair of terminal plates 21, 21, respectively. One end of the terminal 22 is connected to a storage battery (not shown) or the like of an electric circuit, and the other end of the terminal 22 is connected to an electric device (not shown). The current supply path 30 may be formed of a metal other than copper or may be formed of an alloy of copper and another metal. Examples of metals other than copper contained in the current supply path 30 include manganese (Mn), nickel (Ni), and platinum (Pt).

[0017] In the above-described configuration, when an abnormality such as an accident (collision) or breakdown in a vehicle is detected by an abnormality detection device (not shown), the control unit 24 receives a notification signal from the abnormality detection device and supplies a predetermined amount of current to the pair of terminal pins 12, 12 of the igniter 10. The heat and pressure generated by the activation of the ignition unit 11 push the moving member 40 toward the current supply path 30. As shown in FIG. 2 , the tip of the moving member 40 then damages the central portion of the current supply path 30, cutting the current supply path 30. The moving member 40 then stops after hitting the bottom 20e of the cutting chamber 20. In the present invention, it is preferable that the current supply path 30 that is cut off is the wiring from the positive electrode. Furthermore, in the present embodiment, the current supply path 30 is cut off by directly receiving the flame (energy) of the igniter 10, but the current supply path 30 may be cut off by indirectly receiving the flame (energy) of the igniter 10. For example, one end of a tube may be provided at the tip of the igniter 10, and a movable member may be movably installed at the other end of the tube.

[0018] The current interruption device 100 of this embodiment can achieve the following advantageous effects. Specifically, since the time from application of current to ignition of the ignition charge is 300 μs or less, when an abnormality such as an accident (collision) or malfunction is detected in a vehicle or the like, the control unit 24 activates the igniter 10 as a destructive force source more quickly than conventional devices. The igniter 10 applies heat and pressure (energy) to the moving member 40 in the direction of the current supply path 30. As a result, the tip of the moving member 40, which has moved toward the current supply path 30, can cut off the current supply path 30. This allows the current supply to electrical equipment mounted on a vehicle or the like to be interrupted more quickly than conventional devices, thereby preventing electrical leakage and electric shock more quickly than conventional devices.

[0019] Furthermore, because igniter 10 is capable of ignition with lower energy than conventional devices, it is possible to make the capacitor used in the device used for ignition smaller and to use thinner harnesses. Furthermore, while conventional current breakers mainly use an ignition signal from an airbag ECU (Electronic Control Unit) to ignite the igniter, current breaker device 100 of the present embodiment has the advantage of being able to operate even under conditions in which the airbag ECU does not operate (for example, when the ignition key is OFF), by using igniter 10.

[0020] The current breaker of this embodiment is not limited to use in automobiles, but can also be applied to various devices having electrical circuits, such as aircraft, ships, and electrical appliances.

[0021] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments. The scope of the present invention is indicated by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. Furthermore, the embodiments and modifications of the present invention may be combined as appropriate.

[0022] REFERENCE SIGNS LIST 10 Igniter 11 Igniter portion 12 Terminal pin 20 Cutting chamber 20a, 20b Through hole 20c Top portion 20d Side portion 20e Bottom portion 21 Terminal board 22 Terminal 24 Control portion 30 Current supply path 40 Moving member 100 Current interruption device

Claims

1. A current interruption device, comprising: a housing having a top portion, a bottom portion, and side portions and enclosing an accommodation space therein; an igniter provided on the top portion of the housing, wherein the time from the application of current to the ignition of the ignition charge is 300 μs or less; a moving member disposed within the housing and movable within the accommodation space by energy directly or indirectly received from the actuated igniter; and a conductor that is installed within the accommodation space while passing through the side portion of the housing and forms a part of an electrical circuit, and is a current supply path that can be cut by the moving member that has moved during operation.

2. A current interruption device, comprising: a housing having a top portion, a bottom portion, and side portions and enclosing an accommodation space therein; an ignition portion including an ignition charge and a semiconductor bridge device for igniting the ignition charge, and an igniter provided on the top portion of the housing; a moving member disposed within the housing and movable within the accommodation space by energy directly or indirectly received from the actuated igniter; and a conductor that is installed within the accommodation space while passing through the side portion of the housing and forms a part of an electrical circuit, and is a current supply path that can be cut by the moving member that has moved during operation.

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