Blocking device

Abstract

To provide a breaker capable of improving the reliability of operation.SOLUTION: A breaker 1 includes: a conductive path 2; a pyrotechnic circuit breaker 3; multiple drive circuits 4, 5, 6, and 7 that are connected in parallel to the pyrotechnic circuit breaker 3 to operate the pyrotechnic circuit breaker 3; and a control circuit 8. The control circuit 8 is configured to supply electric power for the drive circuits 4, 5, 6, and 7 to operate the pyrotechnic circuit breaker 3 by setting the output current value and output period individually for the drive circuits 4, 5, 6, and 7 when the operation of the pyrotechnic circuit breaker 3 is required.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a cutoff device used for various vehicle electrical devices.

Background Art

[0002] Hereinafter, a conventional cutoff device will be described. The conventional cutoff device has a pyro fuse and a pyro fuse drive circuit. In particular, the pyro fuse drive circuit is provided with a plurality of current detection units, and by comparing the current values detected by the individual current detection units, a failure determination of the current detection unit and a countermeasure against malfunction suppression of the pyro fuse drive circuit have been carried out.

[0003] Note that, as prior art document information related to the invention of this application, for example, Patent Document 1 is known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional cutoff device, a failure of an individual current detection unit in the pyro fuse drive circuit can be determined and diagnosed, and the pyro fuse drive circuit can continue to operate without using information from the failed current detection unit. On the other hand, when the pyro fuse drive circuit itself cannot be driven normally. There is a problem that the reliability of the operation of the cutoff device may decrease.

[0006] Therefore, an object of the present invention is to improve the operation reliability of the cutoff device.

Means for Solving the Problems

[0007] To achieve the above object, the present invention includes a conductive path, an explosive fuse that can irreversibly cut off the conductive path, a plurality of drive circuits that can supply power to operate the explosive fuse and are connected in parallel to the explosive fuse, and a control circuit that can control the operation of the plurality of drive circuits. The control circuit sets an output current value and an output period individually for the plurality of drive circuits when the operation of the explosive fuse is required, and supplies power for the explosive fuse to operate from the plurality of drive circuits.

Advantages of the Invention

[0008] According to the present invention, a plurality of drive circuits for operating the explosive fuse are provided. Further, since the drive circuits are connected in parallel to the explosive fuse and are redundantly arranged even if some of the drive circuits fail, the explosive fuse can operate with high reliability. Furthermore, the plurality of drive circuits can individually set different values for the output current and the output period of the output current, and the plurality of drive circuits can supply power to the explosive fuse according to the situation. As a result, the operation reliability of the cutoff device can be improved.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] (Embodiment) FIG. 1 is a first circuit block diagram showing the configuration of the cutoff device according to the embodiment of the present invention. The cutoff device 1 includes a conductive path 2, an explosive cutoff device 3, a first drive circuit 4, a second drive circuit 5, a third drive circuit 6, a fourth drive circuit 7 which are a plurality of drive circuits, and a control circuit 8. The explosive cutoff device 3 can irreversibly set the conductive path 2 in a cutoff state. The first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 provided in parallel with the explosive cutoff device 3 can supply power for operating the explosive cutoff device 3. And the control circuit 8 can control the operations of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7.

[0012] When the operation of the explosive cutoff device 3 is necessary, the control circuit 8 supplies power for operating the explosive cutoff device 3 from the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7. Here, the control circuit 8 can control the output current value and the output period individually for the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7.

[0013] With the above configuration and operation, a first drive circuit 4, a second drive circuit 5, a third drive circuit 6, and a fourth drive circuit 7, which are a plurality of drive circuits for operating the pyrotechnic circuit breaker 3, are provided. Further, since the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 are connected in parallel to the pyrotechnic circuit breaker, even if a part of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 fails, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 are in a redundant arrangement. Therefore, the pyrotechnic circuit breaker 3 can operate with high reliability. Further, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can individually control the value of the output current and the output period of the output current, and the value of the output current and the output period of the output current of each of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can be set to different values. In other words, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can supply power to the pyrotechnic circuit breaker 3 according to the situation. As a result, the operation reliability of the cutoff device 1 can be improved.

[0014] The details of the cutoff device 1 will be described below with reference to the second circuit block diagram showing the configuration of the cutoff device in the embodiment of the present invention in FIGS. 1 and 2 and the operation curve diagram of the cutoff device in the embodiment of the present invention in FIG. 3.

[0015] The cutoff device 1 includes a conductive path 2, a pyrotechnic circuit breaker 3, a first drive circuit 4, a second drive circuit 5, a third drive circuit 6, and a fourth drive circuit 7 which are a plurality of drive circuits, and a control circuit 8. The cutoff device 1 is mounted on the vehicle body 10 of the vehicle 9, and the power for operating the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, the fourth drive circuit 7, and the control circuit 8 is supplied by a power source 11.

[0016] In the figure, the power supply 11 is shown as an example mounted on the vehicle body 10, but the power supply 11 may be included in the cutoff device 1. Further, the power supply 11 is a capacitor or a storage battery in which the power supplied from a vehicle battery (not shown) is stored in a boosted state. Alternatively, the power supply 11 is a power supply device including a capacitor or a storage battery. And since immediate responsiveness of operation is important in the cutoff device 1, it is desirable that a capacitor capable of supplying power at a high current density be used for the power supply 11.

[0017] Also, the conductive path 2 is provided to supply power from a vehicle propulsion drive power supply (not shown) to a vehicle propulsion drive load (not shown). And, for example, a current detector 12 capable of detecting the value of the current flowing through the conductive path 2 is provided on the vehicle body 10 or the cutoff device 1. When the control circuit 8 detects an overcurrent by the current detector 12, the control circuit 8 drives the pyrotechnic cutoff device 3 using the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, the fourth drive circuit 7, or a part of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, the fourth drive circuit 7. When the pyrotechnic cutoff device 3 is driven, the conductive path 2 is physically destroyed and becomes an irreversible cutoff state.

[0018] The first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 are provided connected in parallel to the pyrotechnic cutoff device 3. And the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 are each capable of supplying power for operating a single pyrotechnic cutoff device 3.

[0019] The control circuit 8 can control the operations of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7. The control circuit 8 supplies power for operating the pyrotechnic cutoff device 3 from the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 when the operation of the pyrotechnic cutoff device 3 such as at the time of overcurrent detection as described above is necessary. Here, the control circuit 8 can control the output current value and the output period individually with respect to the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7.

[0020] The pyrotechnic cut-off device 3 is provided for maintaining the safety of the vehicle 9. For this reason, even if a part of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 falls into a failure state, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 are redundantly arranged. Therefore, the pyrotechnic cut-off device 3 can operate with high reliability. The first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 have substantially the same characteristics. In other words, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 are drive devices for the pyrotechnic cut-off device 3 having the same power capacity and capable of outputting the same voltage and the same current. And when all of the cut-off devices 1 are in a sound state and the power supply 11 is sound, after the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 perform substantially the same operation, the first current I1 can be supplied to the pyrotechnic cut-off device 3 as the sum from the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7.

[0021] For example, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can operate with substantially the same period of power output. Also, for example, even when the periods of power output of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 are different, it is sufficient if the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 have a period of overlapping power output. Thereby, it is sufficient if the first current I1 can be supplied to the pyrotechnic cut-off device 3 as the sum from the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7.

[0022] Here, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can individually control the value of the output current and the output period of the output current, and the values of the output currents of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 and the output periods of the output currents can be set to different values. In other words, when not satisfying the condition that all of the cutoff devices 1 are in a sound state and the power supply 11 is in a sound state, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can supply power to the pyrotechnic cutoff device 3 according to the situation. As a result, it becomes possible to improve the operation reliability of the cutoff device 1.

[0023] It is preferable that each of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 has a first power supply circuit 4A, a second power supply circuit 5A, a third power supply circuit 6A, and a fourth power supply circuit 7A capable of setting the output current and the output voltage. Also, it is preferable that each of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 has a first switch 4B, a second switch 5B, a third switch 6B, and a fourth switch 7B capable of switching between a cutoff state and a connection state. And it is preferable that the first power supply circuit 4A and the first switch 4B are connected in series. Similarly, it is preferable that the second power supply circuit 5A and the second switch 5B, the third power supply circuit 6A and the third switch 6B, and the fourth power supply circuit 7A and the fourth switch 7B are connected in series.

[0024] Although Figure 1 shows a simplified connection diagram, strictly speaking, as shown in Figure 2, the pyrotechnic circuit breaker 3 is provided with an ignition resistor 3C. The power supply from the first drive circuit 4 to the pyrotechnic circuit breaker 3 is executed by supplying a constant current from the first power supply circuit 4A of the constant current power supply through the first switch 4B to the ignition resistor 3C connected to the first node 3A and the second node 3B. Here, the first node 3A is connected as the high potential side and the second node 3B is connected as the low potential side. More precisely, the first switch 4B is provided with a high potential switch 4H connected to the first node 3A and a low potential switch 4L connected to the second node 3B, and the high potential switch 4H and the low potential switch 4L are controlled by the control circuit 8 so as to execute the same operation simultaneously. Alternatively, the high potential switch 4H and the low potential switch 4L are controlled by the control circuit 8 so as to be in a connected state or an open state at different timings. Also, here an example is shown in which the high potential switch 4H and the low potential switch 4L are individually provided on the high potential side and the low potential side, but a form in which only one of the high potential switch 4H and the low potential switch 4L is provided may also be acceptable.

[0025] Similarly, the constant currents supplied from the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A of the constant current power supply are supplied to the ignition resistor 3C connected to the first node 3A and the second node 3B through the second switch 5B, the third switch 6B, and the fourth switch 7B. The second switch 5B, the third switch 6B, and the fourth switch 7B are provided with a high potential switch (not shown) connected to the first node 3A and a low potential switch (not shown) connected to the second node 3B, and the high potential switch (not shown) and the low potential switch (not shown) are controlled by the control circuit 8 so as to execute the same operation simultaneously. Similarly, a form in which only one of the high potential switch (not shown) and the low potential switch (not shown) is provided without individually providing the high potential switch (not shown) and the low potential switch (not shown) on the high potential side and the low potential side may also be acceptable.

[0026] Here, when the operation of the pyrotechnic cut-off device 3 is not necessary, specifically, it may be immediately after the start of the vehicle 9 when the vehicle 9 is not in propulsion drive, during a stop when the propulsion drive of the vehicle 9 has stopped after startup, or even when the vehicle 9 is in propulsion drive (while traveling). Naturally, it may also be immediately before the start / stop of the vehicle 9. Further, the fault diagnosis and voltage detection may be executed singly or periodically at predetermined intervals.

[0027] Then, the fault diagnosis of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 by the control circuit 8 may be executed as follows.

[0028] For example, the determination may be executed based on the potential difference generated in the pyrotechnic cut-off device 3 when a weak current or the like is supplied from the first drive circuit 4 to the pyrotechnic cut-off device 3. Then, in sequence, the fault determination may also be executed for the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 in the same manner.

[0029] Also, for example, the control circuit 8 activates the first power supply circuit 4A to make it possible to output a weak current at a level where the pyrotechnic cut-off device 3 does not operate, and based on the potential difference generated in the pyrotechnic cut-off device 3 when the first switch 4B is opened and closed, the fault determination of the first drive circuit 4 including the first power supply circuit 4A and the first switch 4B may be executed. Then, in sequence, the fault determination may also be executed for the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 in the same manner.

[0030] Furthermore, for example, the control circuit 8 activates a test power supply (not shown) provided in parallel connection with the first power supply circuit 4A to the first drive circuit 4 to make it possible to output a weak current at a level where the pyrotechnic cut-off device 3 does not operate, and based on the potential difference generated in the pyrotechnic cut-off device 3 when the first switch 4B is opened and closed, the fault determination of the first drive circuit 4 including the first power supply circuit 4A and the first switch 4B may be executed. Then, in sequence, the fault determination may also be executed for the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 in the same manner.

[0031] After the control circuit 8 executes the diagnosis of faults in the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7, when the control circuit 8 determines that there are no abnormalities or faults in the voltages of all the drive circuits of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, the fourth drive circuit 7 and the power supply 11, the control circuit 8 executes or prepares to execute the following control and operations.

[0032] The control circuit 8 controls the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 so that the first current I1 can be supplied to the pyrotechnic circuit breaker 3. The first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 may each be controlled by the control circuit 8 so that one-fourth of the first current I1 can be output. More specifically, the control circuit 8 controls the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A so that one-fourth of the first current I1 can be output, and at the same time controls the first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B to be connectable.

[0033] Then, when the operation of the pyrotechnic circuit breaker 3 is required, power is supplied to the pyrotechnic circuit breaker 3 at the first current value I1 for the first period T1. Then, the pyrotechnic circuit breaker 3 is driven with a local blasting operation or the like by the ignition resistor 3C, and the conductive path 2 becomes an irreversible cut-off state due to physical destruction.

[0034] In other words, when the control circuit 8 detects an overcurrent state in which the current detector 12 exceeds a predetermined current at the time of 0 in FIG. 3 or detects accident information of the vehicle 9, the control circuit 8 sets the first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B to the connected state. The control circuit 8 causes the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A to output one-fourth of the first current I1 respectively, and supplies the first current value I1 to the squib 3 over the first period T1. Here, the first period T1 may be set as the period during which the first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B are in the connected state, or may be set as the period during which the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A perform an operation capable of supplying the first current I1.

[0035] As a result, when the operation of the squib 3 becomes necessary when it is determined by the control circuit 8 that there are no abnormalities or failures in all the drive circuits, the cutoff device 1, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 share an equal output current and supply the first current I1 to the squib 3 over the first period T1. In other words, when the output of current is required, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can perform stable redundant execution, and the operation reliability of the cutoff device 1 can be improved.

[0036] The first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B may be mechanical switches such as relays or semiconductor switches such as field effect transistors (hereinafter referred to as FETs). Also, as described above, a constant current power supply is preferably mainly used for the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A.

[0037] The first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 may each have a first power supply circuit 4A, a second power supply circuit 5A, a third power supply circuit 6A, and a fourth power supply circuit 7A capable of setting the output current and output voltage. Further, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 may each have a first switch 4B, a second switch 5B, a third switch 6B, and a fourth switch 7B capable of switching between a cutoff state and a connection state. Furthermore, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 may each have a first supply path 4D, a second supply path 5D, a third supply path 6D, and a fourth supply path 7D, which are paths for supplying power from the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A to the squib cut-off device 3. And the first power supply circuit 4A and the first switch 4B may be connected in series. Similarly, the second power supply circuit 5A and the second switch 5B, the third power supply circuit 6A and the third switch 6B, and the fourth power supply circuit 7A and the fourth switch 7B may be connected in series.

[0038] Although a simplified connection diagram is shown in FIG. 1, strictly speaking, as shown in FIG. 2, the squib cut-off device 3 is provided with an ignition resistor 3C. And the power supply from the first drive circuit 4 to the squib cut-off device 3 is executed by supplying the constant current supplied from the first power supply circuit 4A of the constant current power supply to the ignition resistor 3C connected to the first node 3A and the second node 3B through the first switch 4B. Here, the first node 3A is connected as the high potential side and the second node 3B is connected as the low potential side. More strictly, the first switch 4B is provided with a high potential switch 4H connected to the first node 3A and a low potential switch 4L connected to the second node 3B, and the high potential switch 4H and the low potential switch 4L are controlled by the control circuit 8 so as to execute the same operation at the same time. Alternatively, the high potential switch 4H and the low potential switch 4L are controlled by the control circuit 8 so as to be in a connected state or an open state at different timings. Also, here, an example in which the high potential switch 4H and the low potential switch 4L are individually provided on the high potential side and the low potential side is shown, but a form in which only one of the high potential switch 4H and the low potential switch 4L is provided may be used.

[0039] Similarly, the constant current supplied from the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A of the constant current power supply is supplied to the ignition resistor 3C connected to the first node 3A and the second node 3B through the second switch 5B, the third switch 6B, and the fourth switch 7B. And, the second switch 5B, the third switch 6B, and the fourth switch 7B are provided with a high-potential switch (not shown) connected to the first node 3A and a low-potential switch (not shown) connected to the second node 3B, and the high-potential switch (not shown) and the low-potential switch (not shown) are controlled by the control circuit 8 so as to execute the same operation at the same time. Similarly, it may be in a form in which only one of the high-potential switch (not shown) and the low-potential switch (not shown) is provided without separately providing the high-potential switch (not shown) and the low-potential switch (not shown) on the high-potential side and the low-potential side.

[0040] Further, each of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 may have a first power supply terminal 4C, a second power supply terminal 5C, a third power supply terminal 6C, and a fourth power supply terminal 7C for receiving power supply necessary for the operations of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 from the power supply 11.

[0041] When the operation of the squib cut-off device 3 is not necessary, the control circuit 8 can perform diagnosis of normality or failure of the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A and the first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7, and voltage detection of the voltage supplied to the first power supply terminal 4C, the second power supply terminal 5C, the third power supply terminal 6C, and the fourth power supply terminal 7C.

[0042] Here, when the operation of the pyrotechnic cut-off device 3 is not necessary, specifically, it may be immediately after the start of the vehicle 9 when the vehicle 9 is not in propulsion drive, during the stop of the vehicle 9 after startup and during propulsion drive stop, or even when the vehicle 9 is in propulsion drive (while running). Naturally, it may also be immediately before the start / stop of the vehicle 9. Further, the fault diagnosis and voltage detection may be executed singly or periodically at predetermined intervals.

[0043] Then, the fault diagnosis of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 by the control circuit 8 may be executed as follows.

[0044] For example, the determination may be executed based on the potential difference generated in the pyrotechnic cut-off device 3 when a weak current or the like is supplied from the first drive circuit 4 to the pyrotechnic cut-off device 3. Then, in sequence, the fault determination may also be executed for the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 in the same manner.

[0045] For example, the control circuit 8 activates the first power supply circuit 4A to make it possible to output a weak current at a level where the pyrotechnic cut-off device 3 does not operate, and based on the potential difference generated in the pyrotechnic cut-off device 3 when the first switch 4B is opened and closed, the fault determination for the first power supply circuit 4A, or the fault determination for the first switch 4B, or the fault determination for the first drive circuit 4 including the first power supply circuit 4A and the first switch 4B, and further, the fault determination for the first drive circuit 4 including the first power supply circuit 4A, the first switch 4B, and the first supply path 4D may be executed. Then, in sequence, the fault determination may also be executed for the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 in the same manner.

[0046] Furthermore, for example, the control circuit 8 activates a test power supply (not shown) provided in parallel connection with the first power supply circuit 4A to the first drive circuit 4 to make it possible to output a weak current at a level where the pyrotechnic cut-off device 3 does not operate, and based on the potential difference generated in the pyrotechnic cut-off device 3 when the first switch 4B is opened and closed, the fault determination for the first drive circuit 4 including the first power supply circuit 4A and the first switch 4B may be executed. Then, in sequence, the fault determination may also be executed for the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 in the same manner.

[0047] Further, the control circuit 8 executes detection of the voltages supplied to the first power supply terminal 4C, the second power supply terminal 5C, the third power supply terminal 6C, and the fourth power supply terminal 7C, and determination as to whether the detected voltages are normal values. In other words, the control circuit 8 determines whether the power supply 11 is outputting a normal voltage. For example, the control circuit 8 stores the first voltage V1 as a preset value, and may determine that the power supply 11 is in a normal state when the voltages of the first power supply terminal 4C, the second power supply terminal 5C, the third power supply terminal 6C, and the fourth power supply terminal 7C are higher than the first voltage V1. Detection of the voltages supplied to the first power supply terminal 4C, the second power supply terminal 5C, the third power supply terminal 6C, and the fourth power supply terminal 7C may be performed at the first power supply terminal 4C, the second power supply terminal 5C, the third power supply terminal 6C, and the fourth power supply terminal 7C. Alternatively, detection of the voltages supplied to the first power supply terminal 4C, the second power supply terminal 5C, the third power supply terminal 6C, and the fourth power supply terminal 7C may be performed at the power supply terminal 11A of the power supply 11.

[0048] Here, either the determination for the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 or the determination for the voltages of the first power supply terminal 4C, the second power supply terminal 5C, the third power supply terminal 6C, and the fourth power supply terminal 7C may be executed first or simultaneously.

[0049] After the control circuit 8 executes diagnosis of a failure in the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7, and after the control circuit 8 executes determination of the voltages of the first power supply terminal 4C, the second power supply terminal 5C, the third power supply terminal 6C, and the fourth power supply terminal 7C, when the control circuit 8 determines that there are no abnormalities or failures in all of the drive circuits of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 and the voltage of the power supply 11, the control circuit 8 executes or prepares to execute the following control and operations.

[0050] The control circuit 8 controls the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 so that the first current I1 can be supplied to the pyrotechnic circuit breaker 3. The first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 may each be controlled by the control circuit 8 so that one-fourth of the first current I1 can be output. More specifically, the control circuit 8 controls the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A so that one-fourth of the first current I1 can be output, and at the same time controls the first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B to be connectable.

[0051] Then, when the operation of the pyrotechnic circuit breaker 3 is required, power is supplied to the pyrotechnic circuit breaker 3 at the first current value I1 for the first period T1. Then, the pyrotechnic circuit breaker 3 is driven by the ignition resistor 3C with a local blasting operation or the like, and the conductive path 2 becomes an irreversible cutoff state due to physical destruction.

[0052] In other words, when the current detector 12 detects an overcurrent state in which the predetermined current is exceeded at the time of 0 in FIG. 3 or when the control circuit 8 detects accident information of the vehicle 9, the control circuit 8 connects the first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B, and the control circuit 8 causes the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A to output one-fourth of the first current I1 respectively, and supplies the first current value I1 to the pyrotechnic circuit breaker 3 for the first period T1. Here, the first period T1 may be set as the period during which the first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B are in the connected state, or may be set as the period during which the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A perform an operation capable of supplying the first current I1.

[0053] As a result, when the operation of the explosive actuator 3 becomes necessary when it is determined by the control circuit 8 that there are no abnormalities or failures in all the drive circuits, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 of the cutoff device 1 share the output current equally and supply the first current I1 to the explosive actuator 3 over the first period T1. In other words, when the output of current is required, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can perform stable redundant execution, and it becomes possible to improve the operation reliability of the cutoff device 1.

[0054] The first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B may be mechanical switches such as relays or semiconductor switches such as field effect transistors (hereinafter referred to as FETs). Also, as described above, constant current power supplies are preferably mainly used for the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A.

[0055] Here, the second drive circuit group 15Y may be provided in parallel connection to the explosive actuator 3 with respect to the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7. And the second drive circuit group 15Y does not perform failure diagnosis. Here, the second drive circuit group 15Y is provided with a drive circuit (not shown) or a plurality of drive circuits (not shown) connected in parallel.

[0056] In other words, this is a configuration in which it is not necessarily required to perform failure diagnosis on all of the plurality of drive circuits connected in parallel to the explosive actuator 3. As a result, it becomes possible to improve the operation reliability of the cutoff device 1 by performing failure diagnosis only on a part of the drive circuits that require operation among the entire drive circuits.

[0057] In addition, any plurality of drive circuits may be assigned to the first drive circuit group 15X and the second drive circuit group 15Y described above. In FIG. 1, an embodiment is shown in which the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 are assigned to the first drive circuit group 15X. However, it is not limited to the four drive circuits assigned to the first drive circuit group 15X. For example, a plurality of drive circuits determined to be normal after failure diagnosis, or a part of a plurality of drive circuits determined to be normal after failure diagnosis, may be assigned to the first drive circuit group 15X.

[0058] Here, when a drive circuit in a failed state is detected in the failure diagnosis of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 by the control circuit 8, the control circuit 8 performs the following operations. For example, when the control circuit 8 diagnoses and determines that the first drive circuit 4 is in a failed state, the control circuit 8 sets the first drive circuit 4 as a failed drive circuit and controls the first switch 4B to be in an off state or the first power supply circuit 4A not to operate and not to output current. Then, the control circuit 8 may control the normal second drive circuit 5, third drive circuit 6, and fourth drive circuit 7 to be normal drive circuits and operable so that the squib cut-off device 3 can operate. Alternatively, it may be controlled so that the squib cut-off device 3 can operate by making any one of the normal second drive circuit 5, third drive circuit 6, and fourth drive circuit 7 operable.

[0059] Here, for example, the control circuit 8 controls the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 so that the second current I2 can be supplied to the squib cut-off device 3. The second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 may each be controlled by the control circuit 8 to be in a state where one-third of the second current I2 can be output. More specifically, the control circuit 8 controls the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A so that one-third of the second current I2 can be output respectively, and at the same time controls the second switch 5B, the third switch 6B, and the fourth switch 7B to be in a connectable state.

[0060] Then, when the operation of the pyrotechnic circuit breaker 3 is required, power is supplied to the pyrotechnic circuit breaker 3 at a second current value I2 for a second period T2. In other words, when the current detector 12 detects an overcurrent state in which the current exceeds a predetermined current at the time of 0 in FIG. 3 or when accident information of the vehicle 9 is detected, the control circuit 8 connects the second switch 5B, the third switch 6B, and the fourth switch 7B, and the control circuit 8 outputs one-third of the second current I2 to the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A respectively, and supplies the first current I1 to the pyrotechnic circuit breaker 3 over the second period T2. Here, the second period T2 may be set as the period during which the second switch 5B, the third switch 6B, and the fourth switch 7B are in the connected state, or may be set as the period during which the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A execute an operation capable of supplying the second current I2.

[0061] Here, as shown in FIG. 3, the second current I2 is a current value smaller than the first current I1, and it is desirable that the second period T2 be longer than the first period T1. When supplying the first current I1 described above, one-fourth of the first current I1 is output to the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A respectively. The value of one-fourth of the first current I1 at this time is desirably approximately the upper limit or a value close to the upper limit of the individual outputtable currents of the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A. And the value of one-third of the second current I2 output by each of the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 is also approximately a value close to the individual outputtable currents of the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A. And in order to supplement that the second current I2 is a current value smaller than the first current I1 and approximately three-fourths of I1, power is supplied to the pyrotechnic circuit breaker 3 over a second period T2 longer than the first period T1. And the operation of the pyrotechnic circuit breaker 3 is surely executed.

[0062] As a result, when the control circuit 8 determines that there is an abnormality or a fault in the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 of the cutoff device 1 need to operate the squib 3, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 that can operate normally share the output current equally and supply the second current I2 to the squib 3 over the second period T2. In other words, when the output of current is required, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can execute stable redundancy by operating the operable drive circuits, and the operation reliability of the cutoff device 1 can be improved.

[0063] Separately from the above, after the control circuit 8 executes the determination on the voltages of the first power supply terminal 4C, the second power supply terminal 5C, the third power supply terminal 6C, and the fourth power supply terminal 7C, if an abnormality in the voltage of the power supply 11 is detected, the control circuit 8 executes the following operations. For example, the control circuit 8 stores the first voltage V1 as a preset value, and when the voltages supplied to the first power supply terminal 4C, the second power supply terminal 5C, the third power supply terminal 6C, and the fourth power supply terminal 7C are lower than the first voltage V1, it determines that the power supply 11 is in an abnormal state. Although the control circuit 8 operates all of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7, it executes the following control.

[0064] The control circuit 8 controls the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 so that the third current I3 can be supplied to the squib 3. The first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 may each be controlled by the control circuit 8 to be in a state where one-fourth of the third current I3 can be output. More specifically, the control circuit 8 controls the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A so that one-fourth of the third current I3 can be output respectively, and at the same time controls the first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B to be in a connectable state.

[0065] Then, when the operation of the pyrotechnic cut-off device 3 is necessary, power is supplied to the pyrotechnic cut-off device 3 at a third current value I3 for a third period T3. In other words, when the current detector 12 detects an overcurrent state in which the current exceeds a predetermined current at the time of 0 in FIG. 3 or when accident information of the vehicle 9 is detected, the control circuit 8 sets the first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B to the connected state, and the control circuit 8 causes the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A to output one-fourth of the third current I3 respectively, and supplies the third current I3 to the pyrotechnic cut-off device 3 over the third period T3. Here, the third period T3 may be set as the period during which the first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B are in the connected state, or may be set as the period during which the second power supply circuit 5A, the first power supply circuit 4A, the third power supply circuit 6A, and the fourth power supply circuit 7A execute an operation capable of supplying the third current I3.

[0066] Here, as shown in FIG. 3, it is desirable that the third current I3 is a current value smaller than the first current I1, and the third period T3 is a period longer than the first period T1. Since the voltage of the power supply 11 is in an abnormal state and there is a possibility that the power for supplying the first current I1 is insufficient, the third current I3 is suppressed to a current value smaller than the first current I1 in order to suppress the output power. When supplying the first current I1 described above, the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A output one-fourth of the first current I1 respectively. The value of one-fourth of the first current I1 at this time is generally the upper limit or a value close to the upper limit of the individual outputtable currents of the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A.

[0067] In order to supply the third current I3 thereto, the value of one-fourth of the third current I3 output by each of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 is lower than the value of one-fourth of the first current I1. And the value of one-fourth of the third current I3 is a value lower than the upper limit of the individual outputtable currents of the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A or a value close to the upper limit. For example, the value of one-fourth of the third current I3 is a low value set by multiplying a predetermined coefficient of 1.0 or less with respect to the upper limit of the outputtable current of each of the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A. As described above, when supplying the first current I1 to the squib cut-off device 3 and when supplying the third current I3 to the squib cut-off device 3, the individual output currents of the first power supply circuit 4A, the second power supply circuit 5A, the third power supply circuit 6A, and the fourth power supply circuit 7A are controlled by the control circuit 8 as different values.

[0068] And, in order to compensate for the fact that the third current I3 has a smaller current value than the first current I1, power is supplied to the squib cut-off device 3 over a third period T3 that is longer than the first period T1. And the operation of the squib cut-off device 3 is surely executed.

[0069] Thereby, when it is determined by the control circuit 8 that there is an abnormality in the voltage of the power supply 11 and the operation of the squib cut-off device 3 becomes necessary, the interruption device 1 causes the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 to bear equal output currents, and supplies the third current I3 to the squib cut-off device 3 over the third period T3. In other words, when the output of current is required, the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can operate all the drive circuits with less power than normal even when the voltage of the power supply 11 is low, enabling stable redundant execution and improving the operation reliability of the interruption device 1.

[0070] Here, as for the relationship between the second period T2 at the second current value I2 and the third period T3 at the third current value I3 described above, the third current value I3 may be a current value larger than the second current value I2, or the third current value I3 may be a current value smaller than the second current value I2. Furthermore, the third period T3 may be set shorter than the second period T2, or the third period T3 may be set longer than the second period T2.

[0071] As described above, both the second current I2 supplied to the pyrotechnic circuit breaker 3 when a part of the drive circuit fails and the third current I3 supplied to the pyrotechnic circuit breaker 3 when the power supply 11 has a voltage shortage are smaller than the first current I1. However, the value of the second current I2 varies depending on the number of failures of the drive circuit, and the value of the third current I3 varies depending on the degree of voltage drop of the power supply 11. Therefore, the values of the second current I2 and the third current I3 do not maintain a constant magnitude relationship. And as the value of the second current I2 or the third current I3 decreases, the value of the second period T2 or the third period T3 increases. In other words, the control circuit 8 controls the operations of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 so that the integrated value of the current supplied to the pyrotechnic circuit breaker 3 is maintained, such as the energy value obtained by the product of the square value of the current and the period.

[0072] Also, the control circuit 8 determines that the power supply 11 is in an abnormal state according to the voltages supplied to the first power supply terminal 4C, the second power supply terminal 5C, the third power supply terminal 6C, and the fourth power supply terminal 7C. The first voltage V1 used as the criterion for determination may be set to be equal to or higher than the voltage value at which the first switch 4B, the second switch 5B, the third switch 6B, the fourth switch 7B, and the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can operate. Also, the voltage at which the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can operate is higher than the voltage at which the first switch 4B, the second switch 5B, the third switch 6B, and the fourth switch 7B can operate, especially when power conversion operations are involved. Therefore, the first voltage V1 used as the criterion for determination may be set to be equal to or higher than the voltage value at which the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can operate.

[0073] Furthermore, a current detector 12 capable of detecting the load current flowing through the conductive path 2 may be provided and used as a function for transmitting a trigger for operating the pyrotechnic circuit breaker 3.

[0074] As described above, the pyrotechnic circuit breaker 3 executes a cutoff operation in response to the power supplied from each drive circuit according to an instruction from the control circuit 8 in response to an abnormal situation such as detection of overcurrent or detection of a collision in the vehicle 9. Here, for example, when the control circuit 8 determines that the load current flowing through the conductive path 2 has exceeded the overcurrent threshold value, the control circuit 8 may determine that the operation of the pyrotechnic circuit breaker 3 is necessary, and the pyrotechnic circuit breaker 3 may execute the cutoff operation.

[0075] This makes it possible to improve the operation reliability of the cutoff device 1. When the above overcurrent energization is determined, the control circuit 8 instructs the execution of the cutoff operation.

[0076] Also, when a drive circuit in a failed state is detected in the failure diagnosis of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 by the control circuit 8, the control circuit 8 may execute the following operations. When the control circuit 8 diagnoses and determines that the first drive circuit 4 is in a failed state, the control circuit 8 controls the first switch 4B to be in an open state or the first power supply circuit 4A not to operate and not to output current. Then, the control circuit 8 may be controlled by the control circuit 8 so that the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 can each output one-fourth of the first current I1 to the pyrotechnic circuit breaker 3.

[0077] Here, as described above, the first current I1 is the current supplied to operate the pyrotechnic circuit breaker 3 when all the drive circuits can output normally. At that time, since the drive circuit is composed of the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7 as in the example, each drive circuit is controlled by the control circuit 8 to be able to output one-fourth of the first current I1.

[0078] When the detonator cut-off device 3 needs to operate, a current of one-fourth of the first current I1, which is the same value as the value when the first current value was supplied to the detonator cut-off device 3, may be supplied to the individual drive circuits 5, 6, and 7 that are operable drive circuits over a fourth period T4 that is longer than the first period. Thereby, the interruption device 1 can ensure stable operation reliability by operating the operable drive circuits.

[0079] Alternatively, a fourth current I4 having a value larger than one-fourth of the first current I1, which was the value when the first current value was supplied to the detonator cut-off device 3 when the detonator cut-off device 3 needed to operate, may be supplied to the individual drive circuits 5, 6, and 7 that are operable drive circuits over the first period. Thereby, the interruption device 1 can ensure stable operation reliability by operating the operable drive circuits.

[0080] Furthermore, a fourth current I4 having a value larger than one-fourth of the first current I1, which was the value when the first current value was supplied to the detonator cut-off device 3 when the detonator cut-off device 3 needed to operate, may be supplied to the individual drive circuits 5, 6, and 7 that are operable drive circuits over a fifth period T5 that is longer than the first period. Thereby, the interruption device 1 can ensure stable operation reliability by operating the operable drive circuits.

[0081] Here, furthermore, a current detector 12 capable of detecting the load current flowing through the conductive path 2 and a temperature detector 14 capable of detecting the temperature of the conductive path 2 or the relay 13 connected to the conductive path 2 are provided, and it may be used as a function for transmitting a trigger for operating the detonator cut-off device 3.

[0082] As described above, the pyrotechnic circuit breaker 3 executes a cutoff operation in response to power supplied from each drive circuit according to an instruction from the control circuit 8 in response to abnormal conditions such as detection of overcurrent or detection of a collision in the vehicle 9. Here, for example, temperature information of the conductive path 2 or the relay 13 connected to the conductive path 2 is transmitted from the temperature detector 14 to the control circuit 8. When the load current flowing through the conductive path 2 exceeds the overcurrent threshold value, or when the control circuit 8 determines that the temperature rise in the relay 13 due to overcurrent conduction or malfunction in the load current flowing through the conductive path 2 or the relay 13 has exceeded the threshold value and reached the above temperature value, the control circuit 8 may determine that the operation of the pyrotechnic circuit breaker 3 is necessary, and the pyrotechnic circuit breaker 3 may execute a cutoff operation.

[0083] Further, when the load current flowing through the conductive path 2 exceeds the overcurrent threshold value, and when the control circuit 8 determines that the temperature rise in the relay 13 due to overcurrent conduction or malfunction in the load current flowing through the conductive path 2 or the relay 13 has exceeded the threshold value and reached the above temperature value, the control circuit 8 may determine that the operation of the pyrotechnic circuit breaker 3 is necessary, and the pyrotechnic circuit breaker 3 may execute a cutoff operation. Thereby, it becomes possible to improve the operation reliability of the cutoff device 1.

[0084] Regarding the determination of the above overcurrent conduction and the determination of the temperature rise, when either one is determined, the control circuit 8 instructs the execution regarding the cutoff operation. Alternatively, regarding the determination of the above overcurrent conduction and the determination of the temperature rise, when both are determined, the control circuit 8 instructs the execution regarding the cutoff operation.

[0085] Alternatively, as a condition for not executing the cutoff operation, a case where the control circuit 8 determines an overcurrent due to noise generated at the start of the vehicle 9 may be set.

[0086] In the embodiment described above, an example was shown in which power is supplied to the pyrotechnic circuit breaker 3 with four drive circuits, i.e., the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7, connected in parallel as a plurality of drive circuits. However, the plurality of drive circuits may be arranged with two or more drive circuits connected in parallel, and the present invention is not limited to the state where four drive circuits are connected in parallel.

[0087] Further, in the above description, the control circuit 8 is described as an element that performs all operations related to determination, commands related to control, and execution. Strictly speaking, the control circuit 8 may have an ignition signal output unit 8A for operating the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7, a failure diagnosis unit 8B for performing failure diagnosis on the first drive circuit 4, the second drive circuit 5, the third drive circuit 6, and the fourth drive circuit 7, and the like. Further, the control circuit 8 may further have a storage device (not shown), and the control circuit 8 is not limited to a single element and may be distributed and arranged for each function.

Industrial Applicability

[0088] The cutoff device of the present invention has an effect of improving the operation reliability and is useful in various vehicle electrical devices.

Explanation of Signs

[0089] 1 Cutoff device 2 Conductive path 3 Pyrotechnic circuit breaker 3A First node 3B Second node 3C Ignition resistor 4 First drive circuit 4A First power supply circuit 4B First switch 4C First power supply terminal 4D First supply path 4H High-potential switch 4L Low-potential switch 5 Second drive circuit 5A Second power supply circuit 5B Second switch 5C Second power supply terminal 5D Second supply path 6 Third drive circuit 6A Third power supply circuit 6B Third switch 6C Third power supply terminal 6D Third supply path 7 Fourth drive circuit 7A Fourth power supply circuit 7B Fourth switch 7C Fourth power supply terminal 7D Fourth supply path 8 Control circuit 8A Ignition signal output section 8B Fault diagnosis section 9 Vehicle 10 Vehicle body 11 Power supply 12 Current detector 13 Relay 14 Temperature detector 15X First drive circuit group 15Y Second drive circuit group

Claims

1. A conductive path, An explosive fuse capable of irreversibly shutting off the conductive path, A first drive circuit group capable of supplying power for operating the explosive fuse and having a plurality of drive circuits connected in parallel to the explosive fuse, A control circuit capable of controlling the operation of the plurality of drive circuits, Comprising, When the operation of the explosive fuse is required, the control circuit controls the output current value and the output period for each of the plurality of drive circuits to supply power for the explosive fuse to operate from the first drive circuit group. A cutoff device.

2. The control circuit, When the operation of the explosive fuse is not required, it is possible to execute diagnosis of normality or failure for the plurality of drive circuits, When it is diagnosed that all of the plurality of drive circuits in the first drive circuit group are normal, Thereafter, when the operation of the explosive fuse is required, power is supplied to the explosive fuse at a first current value for a first period. The cutoff device according to claim 1.

3. Each of the plurality of drive circuits, Has a power supply terminal capable of receiving power supply necessary for the operation of the plurality of drive circuits, and can execute switching between supplying and not supplying power to the explosive fuse, The control circuit, When the operation of the explosive fuse is not required, it is possible to execute diagnosis of normality or failure for the plurality of drive circuits and detection of the voltage supplied to the power supply terminal, When it is diagnosed that all of the plurality of drive circuits in the first drive circuit group are normal and it is detected that the voltage supplied to the power supply terminal is equal to or higher than a first voltage value, Thereafter, when the operation of the explosive fuse is required, power is supplied to the explosive fuse at a first current value for a first period. The cutoff device according to claim 1.

4. Each of the plurality of drive circuits, Has a power supply circuit having a power supply terminal capable of receiving power supply necessary for the operation of the plurality of drive circuits, a supply path, and a switch capable of executing switching between supplying and not supplying power to the explosive fuse, The control circuit, When the operation of the explosive fuse is not required, it is possible to execute diagnosis of normality or failure for the power supply circuit, the supply path, and the switch in the plurality of drive circuits and detection of the voltage supplied to the power supply terminal. When it is diagnosed that all of the power supply circuit, the supply path, and the switch in the plurality of drive circuits in the first drive circuit group are normal, and it is detected that the voltage supplied to the power supply terminal is equal to or higher than a first voltage value, subsequently, when the operation of the pyrotechnic cut-off device is necessary, power is supplied to the pyrotechnic cut-off device at a first current value over a first period. The cut-off device according to claim 1.

5. A second drive circuit group connected in parallel with the plurality of drive circuits to the pyrotechnic cut-off device, further comprising, wherein the second drive circuit group does not perform a failure diagnosis. The cut-off device according to claim 3.

6. When there is a failed drive circuit diagnosed as a failure in the first drive circuit group, power output is stopped from the failed drive circuit when the operation of the pyrotechnic cut-off device is necessary, and power is supplied to the pyrotechnic cut-off device from the normal drive circuits diagnosed as normal among the plurality of drive circuits when the operation of the pyrotechnic cut-off device is necessary. The cut-off device according to claim 3.

7. The control circuit, when there is a failed drive circuit diagnosed as a failure in the first drive circuit group, power output is stopped from the failed drive circuit when the operation of the pyrotechnic cut-off device is necessary, and power is supplied to the pyrotechnic cut-off device at a second current value smaller than the first current value over a second period longer than the first period from the normal drive circuits diagnosed as normal among the plurality of drive circuits when the operation of the pyrotechnic cut-off device is necessary. The cut-off device according to claim 3.

8. The control circuit, when it is detected that the voltage supplied to the power supply terminal is a value smaller than the first voltage value, when the operation of the pyrotechnic cut-off device is necessary, power is supplied to the pyrotechnic cut-off device at a third current value smaller than the first current value over a third period longer than the first period. The cut-off device according to claim 3.

9. further comprising a current detector capable of detecting a load current flowing through the conductive path, wherein the current detector is connected to the control circuit, and when the load current rises above a threshold value, the control circuit determines that it is a time when the operation of the pyrotechnic cut-off device is necessary. The cut-off device according to claim 1.

10. a current detector capable of detecting a load current flowing through the conductive path, and a temperature detector capable of detecting the temperature of the conductive path or the temperature of a switch connected to the conductive path, further comprising, wherein both the current detector and the temperature detector are connected to the control circuit. When either the load current or the temperature rises above a threshold value, the control circuit determines that it is time for the pyrotechnic circuit breaker to operate. The interrupting device according to claim 1.

11. A current detector capable of detecting a load current flowing through the conductive path, A temperature detector capable of detecting the temperature of the conductive path or the temperature of a switch connected to the conductive path, further comprising The current detector and the temperature detector are both connected to the control circuit, When both the load current and the temperature rise above a threshold value, the control circuit determines that it is time for the pyrotechnic circuit breaker to operate. The interrupting device according to claim 1.

12. The control circuit When the operation of the pyrotechnic circuit breaker is not required, it is possible to perform diagnosis of normality or failure of the plurality of drive circuits and detection of the voltage supplied to the power supply terminal, When it is diagnosed that all of the plurality of drive circuits are normal and it is detected that the power supply terminal is at a first voltage value or higher, After that, when the operation of the pyrotechnic circuit breaker is required, the plurality of drive circuits execute an operation, and power is supplied to the pyrotechnic circuit breaker at a first current value for a first period. The interrupting device according to claim 3.

13. A second drive circuit group connected in parallel with the first drive circuit group to the pyrotechnic circuit breaker, further comprising The second drive circuit group does not perform a failure diagnosis. The interrupting device according to claim 12.

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