Power interruption device

Abstract

The present invention provides a power interruption device capable of preventing unintended activation of a pyrofuse device when it is being disposed of or replaced. [Solution] The power interruption device comprises a pyrofuse device 21, a receiving unit 25, and a control device 22. The pyrofuse device 21 is installed in the power system of the vehicle 10 and is configured to interrupt the power system when an abnormality in the vehicle 10 is detected. The receiving unit 25 receives a signal from outside the vehicle 10 requesting the operation of the pyrofuse device 21. The control device 22 operates the pyrofuse device 21 when the receiving unit 25 receives the above signal.

Description

Technical Field

[0001] The present disclosure relates to a power cut-off device.

Background Art

[0002] As a power cut-off device for a power system, a pyro fuse device (gunpowder type cut-off switch) is known. For example, in Japanese Unexamined Patent Application Publication No. 2023-35315 (Patent Document 1), it is described that in a vehicle, a pyro fuse device is provided in a power line between a battery and a load operated by electric power from the battery, and an electric circuit is cut using the explosive force of gunpowder in the pyro fuse. Thereby, it is said that it is possible to suppress the application of voltage to the power line during a vehicle collision or the like and ensure safety.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the pyro fuse device configured as described above, since the pyro fuse device does not operate unless there is a vehicle collision or the like, when the pyro fuse device or the equipment equipped with the pyro fuse device is discarded or replaced, there is a possibility that the pyro fuse device may operate unintentionally due to malfunction.

[0005] The present disclosure has been made to solve such problems, and an object of the present disclosure is to provide a power cut-off device capable of preventing the unintended driving of a pyro fuse device when the pyro fuse device is discarded or replaced.

Means for Solving the Problems

[0006] The power interruption device of this disclosure comprises a pyrofuse device, a receiving unit, and a control unit. The pyrofuse device is installed in the vehicle's power system and is configured to interrupt the power system when an abnormality in the vehicle is detected. The receiving unit receives a signal from outside the vehicle requesting the pyrofuse device to be driven. The control unit drives the pyrofuse device when the receiving unit receives the signal.

[0007] In the above-described power interruption device, by including a receiver and a control device, it becomes possible, for example, for a user to connect an operating tool from outside the vehicle and arbitrarily drive the pyrofuse device through the receiver via the operating tool. As a result, when disposing of or replacing the pyrofuse device, the user can drive the pyrofuse device as needed, thereby preventing unintended operation of the pyrofuse device.

[0008] The power interruption device may further include a case in which a pyrofuse device is housed. The case may have an opening / closing section, and the control device may drive the pyrofuse device on the condition that the opening / closing section is closed.

[0009] This prevents fragments (such as severed busbars) generated during the operation of the pyrofuse device from scattering outside the case.

[0010] The control device may be configured to drive the pyrofuse device only if there is a fault record indicating that an electrical unit installed in the power system has failed.

[0011] If there is no record of a malfunction in the electrical unit, it is considered unnecessary to activate the pyrofuse device when replacing or disposing of it. This configuration prevents accidental activation of the pyrofuse device by user error when there is no record of a malfunction in the electrical unit. As a result, unintended activation of the pyrofuse device can be prevented.

[0012] The electrical unit may be a charging unit that charges the vehicle's battery using power supplied from an external power source, and the pyro fuse device may be provided in the charging unit.

[0013] Furthermore, the electrical unit may be a battery unit mounted on the vehicle, and the pyro-fuse device may be provided on the battery unit.

[0014] Furthermore, the electrical unit may be a motor drive unit mounted on the vehicle, and the pyro fuse device may be provided on the motor drive unit. [Effects of the Invention]

[0015] The power interruption device of this disclosure can prevent unintended activation of the pyrofuse device when it is being disposed of or replaced. [Brief explanation of the drawing]

[0016] [Figure 1] This diagram shows a schematic configuration of a vehicle equipped with a power interruption device. [Figure 2] This is a diagram showing the configuration of a power interruption device according to this embodiment. [Figure 3] This diagram shows the state after the pyrofuse device has been activated. [Figure 4] This diagram shows the configuration of a charging unit equipped with a pyro-fuse device. [Figure 5] This is a functional block that functionally illustrates the configuration of the control device. [Figure 6] This flowchart shows an example of the procedure for processing performed by the control device. [Modes for carrying out the invention]

[0017] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0018] Here, a case where the power cut-off device of the present disclosure is mounted on a vehicle and the pilot fuse of the power cut-off device is provided in the charging unit will be described as an example.

[0019] FIG. 1 is a diagram showing a schematic configuration of a vehicle 10 on which the power cut-off device according to the present embodiment is mounted. In the present embodiment, the vehicle 10 is an electric vehicle capable of traveling using electric power stored in a battery, for example, a BEV (Battery Electric Vehicle), but may be a PHEV (Plug-in Hybrid Electric Vehicle) equipped with an engine separately, etc.

[0020] Referring to FIG. 1, the vehicle 10 includes a battery 30, a charging port 40, a drive device 50, tires 60, a charging unit 70, and a power cut-off device.

[0021] The battery 30 is a rechargeable power storage device, for example, a lithium-ion secondary battery. The battery 30 stores electric power for traveling and can output the stored electric power to the drive device 50. Further, the battery 30 can store electric power supplied from an external power source (hereinafter referred to as "external power source") outside the vehicle connected to the charging port 40 and electric power regenerated by a motor (not shown) of the drive device 50 when the vehicle 10 brakes, etc.

[0022] The charging port 40 is configured to be able to connect a connector of a charging cable of an external power source (not shown), and outputs the electric power supplied from the external power source to the charging port 40 through the charging cable to the charging unit 70. The charging port 40 may be one on the vehicle 10 or may be two or more. Further, the charging port 40 may include a lid.

[0023] The charging unit 70 includes a boost converter 72 and a power cutoff device. The boost converter 72 boosts the voltage of the power input from the charging port 40 (power supplied from an external power source) to the battery 30 if the voltage of the power input from the charging port 40 is lower than the voltage of the battery 30. For example, if the voltage of the battery 30 is 800V and the voltage of the power supplied from the external power source is 400V, the boost converter 72 boosts the 400V power supplied from the external power source to 800V and supplies it to the battery 30. The boost converter 72 is composed of, for example, a DC / DC converter having an isolation transformer.

[0024] The power interruption device is a device capable of interrupting the electrical circuit (charging circuit) between the charging port 40 and the battery 30, and consists of a pyrofuse device 21, a control device 22, a ground fault detection device 23, and a receiving unit 25. In this embodiment, the pyrofuse device 21, the control device 22, and the ground fault detection device 23 are provided in the charging unit 70, and the charging power from the external power supply supplied to the battery 30 can be interrupted by the pyrofuse device 21.

[0025] In Figure 1, the pyrofuse device 21 is located in the circuit between the charging port 40 and the boost converter 72, but it may also be located in the circuit between the boost converter 72 and the battery 30. Similarly, the ground fault detection device 23 is located in the circuit between the boost converter 72 and the battery 30, but it may also be located in the circuit between the charging port 40 and the boost converter 72. Furthermore, the control device 22 and the ground fault detection device 23 may be located outside the charging unit 70.

[0026] The receiving unit 25 can communicate with an external operating tool 80 and receive various signals from the operating tool 80. The operating tool 80 is, for example, a scan tool or fault diagnosis tool used by dealers, and can acquire the status of the vehicle 10 and make various settings on the vehicle 10. In this embodiment, the user (dealer) can request the operation of the pyrofuse device 21 from the operating tool 80. The receiving unit 25 may also be provided within the charging unit 70 together with the control device 22, etc. Details of the power cutoff device will be described later.

[0027] The drive unit 50 is a device for driving the vehicle 10 and is composed of, for example, a motor and an inverter. The drive unit 50 converts the DC power supplied from the battery 30 into AC power using the inverter and drives the motor (AC motor). The tires 60 rotate by receiving the driving force of the motor of the drive unit 50, causing the vehicle 10 to move. When the vehicle 10 is braking or driving downhill, the motor of the drive unit 50 generates regenerative power by receiving the rotational force of the tires 60, and the battery 30 is charged.

[0028] In recent years, in vehicles like vehicle 10, which can charge their onboard batteries using an external power source, there has been a growing demand for rapid charging to shorten charging times. Rapid charging charges the battery with high voltage and high current, and if the voltage of the external power source is lower than the battery voltage, the power supplied from the external power source is boosted and supplied to the battery. In this vehicle 10, a charging unit 70 is provided on the charging path, which is the power line connecting the charging port 40 to the battery 30, and the charging power supplied from the external power source through the charging port 40 is boosted by the charging unit 70 to charge the battery 30.

[0029] Furthermore, this vehicle 10 is equipped with a power interruption device to interrupt the current flowing through the charging path from the charging port 40 to the battery 30 in the event of a ground fault or short circuit occurring during charging of the battery 30 by the charging unit 70 (hereinafter referred to as "external charging").

[0030] Figure 2 shows the configuration of a power interruption device according to this embodiment. Referring to Figure 2, the power interruption device 20 is composed of a pyrofuse device 21, a control device 22, a ground fault detection device 23, and a receiving unit 25.

[0031] The pyrofuse device 21 is installed in the charging path from the charging port 40 to the battery 30 and can physically cut the charging path according to a drive signal from the control device 22. Specifically, the pyrofuse device 21 includes a cutting member 24 and a pyrofuse drive circuit (not shown). When the pyrofuse drive circuit receives a drive signal from the control device 22, the cutting member 24 is driven by the pyrofuse drive circuit. The cutting member 24 is ejected towards the charging path by the explosive force of the gunpowder, physically cutting the charging path. The charging path is, for example, a busbar or wiring that constitutes a power line.

[0032] When a ground fault or short circuit in a charging circuit is detected by the ground fault detection device 23, the pyrofuse device 21 is driven by the control device 22, which receives a detection signal from the ground fault detection device 23, and cuts the charging circuit with the cutting member 24.

[0033] Furthermore, when the receiving unit 25 receives a signal from the operating tool 80 outside the vehicle requesting the pyrofuse device 21 to be driven, the control device 22, which receives the request signal from the receiving unit 25, drives the pyrofuse device 21 and cuts the charging circuit with the cutting member 24.

[0034] The ground fault detection device 23 is installed in the charging path from the charging port 40 to the battery 30, and in this example, it is installed in the output circuit of the boost converter 72 within the charging unit 70. The ground fault detection device 23 detects ground faults occurring in the charging path and outputs the detection signal to the control device 22. Various known ground fault detectors can be used in the ground fault detection device 23, for example, by detecting voltage or current changes between two high resistors connected between power lines, or by detecting current balance between power lines, thereby detecting ground faults in the charging path.

[0035] The receiving unit 25 is an interface device for communicating with an external operating tool 80 (Figure 1), and receives signals from the operating tool 80, for example, via CAN (Controller Area Network) communication. In this embodiment, a user of the operating tool 80 (e.g., a dealer) can request the operation of the pyrofuse device 21 from the operating tool 80. When the receiving unit 25 receives the request signal for operation of the pyrofuse device 21 from the operating tool 80, it outputs the received request signal to the control device 22. The communication between the operating tool 80 and the receiving unit 25 may be wired or wireless.

[0036] The control device 22 is composed of a microcontroller 22 and includes a processor, memory (ROM (Read Only Memory) and RAM (Random Access Memory)), signal input / output ports, etc. (none of which are shown). Ground fault detection signals from the ground fault detection device 23 and signals received by the receiving unit 25 from the external operating tool 80 are input through the signal input / output ports, and various processes are executed by the processor according to the program stored in the ROM.

[0037] Figure 3 shows the state after the pyrofuse device 21 has been activated. Referring to Figure 3, in this example, the electrical circuit (charging circuit) at the location where the pyrofuse is placed is composed of a busbar. In response to the drive signal from the control device 22, the explosive is detonated, and the force of the explosion propels the cutting member 24 toward the busbar, cutting the busbar. The cutting member 24 is composed of, for example, a piston-shaped insulating member, and physically cuts the busbar, making it impossible to conduct electricity.

[0038] Figure 4 shows the configuration of a charging unit 70 in which a pyrofuse device 21 is provided. Referring to Figure 4, the charging unit 70 includes a boost device 72 and a case 74. Inside the case 74, together with the boost device 72, the pyrofuse device 21, a control device 22, and a ground fault detection device 23 are housed.

[0039] The case 74 is provided with an opening / closing section 76. The opening / closing section 76 allows for inspection of the inside of the charging unit 70, and for removal of the pyrofuse device 21 from inside the charging unit 70 through the opening / closing section 76 when replacing or disposing of the pyrofuse device 21.

[0040] The case 74 contains high-voltage components (booster 72), and when the pyrofuse device 21 is activated, explosives for ejecting the cutting member 24 toward the busbar explode, and the cutting member 24 is ejected toward the busbar at high speed. Therefore, an interlock is provided for the opening / closing section 76. Specifically, the open / closed state of the opening / closing section 76 is detected, and when the opening / closing section 76 is open, the booster device 72 cannot be energized or operated, and the pyrofuse device 21 cannot be operated.

[0041] In this embodiment, the opening / closing section 76 is provided near the location of the pyrofuse device 21 in order to facilitate the removal of the pyrofuse device 21 from the charging unit 70 through the opening / closing section 76 when replacing or disposing of the pyrofuse device 21. The opening / closing section 76 has sufficient strength to prevent the cutting member 24 ejected when the pyrofuse device 21 is activated from penetrating it. The case 74 may also have the same strength as the opening / closing section 76.

[0042] Figure 5 is a functional block illustrating the configuration of the control device 22. Referring to Figure 5, the control device 22 includes a microcontroller 26, a case status confirmation unit 27a, a fault history confirmation unit 27b, and a signal confirmation unit 27c.

[0043] The case status confirmation unit 27a acquires a signal indicating the open / closed state of the open / closed section 76 provided on the case 74 of the charging unit 70, and confirms the open / closed state of the open / closed section 76. The case status confirmation unit 27a then outputs a signal to the microcontroller 26 that is activated (logically high) when, for example, the open / closed section 76 is in the closed state.

[0044] The fault history confirmation unit 27b acquires information regarding the diagnostics (self-diagnosis) of the charging unit 70. In this embodiment, when a predetermined fault is detected in the charging unit 70, the fault is recorded as a diagnostic. The faults recorded are, for example, faults that require replacement of the charging unit 70. The fault history confirmation unit 27b acquires the fault history of the charging unit 70 recorded by the diagnostics. The fault history confirmation unit 27b then outputs a signal to the microcontroller 26 that is activated (logically high) when there is a fault history of the charging unit 70.

[0045] The signal confirmation unit 27c receives the signal from the external operating tool 80, which is received by the receiving unit 25, from the receiving unit 25. The signal confirmation unit 27c then checks whether the operating tool 80 has requested that the pyrofuse device 21 be driven, and outputs a signal to the microcontroller 26 that is activated (logically high) when the pyrofuse device 21 is requested to be driven.

[0046] When the microcontroller 26 receives a ground fault detection signal from the ground fault detection device 23, it outputs a drive signal to the pyrofuse device 21 to drive the pyrofuse. The microcontroller 26 also receives the above output signals from the case status confirmation unit 27a, the fault history confirmation unit 27b, and the signal confirmation unit 27c, respectively.

[0047] Then, when the signal from the signal confirmation unit 27c is activated, and the signals from the case status confirmation unit 27a and the fault history confirmation unit 27b are also activated, the microcontroller 26 outputs a drive signal to the pyrofuse device 21 to drive the pyrofuse. For example, the microcontroller 26 calculates the logical AND of the signals from the case status confirmation unit 27a, the fault history confirmation unit 27b, and the signal confirmation unit 27c, and outputs a drive signal to the pyrofuse device 21 when the result of that calculation indicates a logical high.

[0048] Thus, in this embodiment, the pyrofuse device 21 can be driven from an external operating tool 80 via the receiving unit 25. When the operating tool 80 requests that the pyrofuse device 21 be driven, the microcontroller 26 drives the pyrofuse device 21 only if the opening / closing part 76 of the case 74 of the charging unit 70 is in the closed state and there is a fault history of the charging unit 70. This prevents the pyrofuse device 21 from operating when the opening / closing part 76 of the case 74 is in the open state, and also prevents the pyrofuse device 21 from being operated by a malfunction of the operating tool 80 even though the charging unit 70 is functioning normally.

[0049] Figure 6 is a flowchart showing an example of the procedure for processing performed by the control device 22. This flowchart shows the pre-processing procedure when disposing of or replacing the pyrofuse device 21. When the operating tool 80 is connected to the vehicle 10 (receiving unit 25) by the user (dealer, etc.) during vehicle maintenance, the series of processes shown in this flowchart are initiated.

[0050] Referring to Figure 6, the control device 22 determines whether the receiving unit 25 has received a signal from the operating tool 80 requesting the operation of the pyrofuse device 21 (step S10). If the receiving unit 25 determines that it has not received the above signal from the operating tool 80 (NO in step S10), the control device 22 proceeds to the end without executing the subsequent series of processes.

[0051] In step S10, if the receiving unit 25 determines that it has received the above signal from the operating tool 80 (YES in step S10), the control device 22 determines whether the opening / closing part 76 of the case 74 of the charging unit 70 is in the closed state (step S20). If it is determined that the opening / closing part 76 is in the open state (NO in step S20), the control device 22 proceeds to the end without executing the subsequent series of processes.

[0052] If it is determined in step S20 that the opening / closing section 76 is in the closed state (YES in step S20), the control device 22 acquires the diagnostic history of the charging unit 70 and determines whether or not there is a fault record for the charging unit 70 (step S30). If it is determined that there is no fault record for the charging unit 70 (NO in step S30), the control device 22 proceeds to the end without executing step S40.

[0053] On the other hand, if it is determined in step S30 that there is a fault record for the charging unit 70 (YES in step S30), the control device 22 drives the pyrofuse device 21 in accordance with the drive request for the pyrofuse device 21 from the operating tool 80 (step S40).

[0054] In the above, it is assumed that the pyrofuse device 21 is driven when the receiving unit 25 receives a drive request signal for the pyrofuse device 21 from the operating tool 80, the opening / closing part 76 of the case 74 of the charging unit 70 is in the closed state (YES in step S20), and there is a fault history of the charging unit 70 (YES in step S30). However, either or both of steps S20 and S30 may be omitted.

[0055] In other words, even if the opening / closing part 76 of the case 74 is in the open position, if, for example, the operation of the pyrofuse device 21 is permitted in a space where human entry is prohibited, the processing in step S20 may be omitted. Also, the pyrofuse device 21 may be driven according to the drive request from the operating tool 80, regardless of whether or not there is a fault record of the charging unit 70.

[0056] As described above, in this embodiment, a user (such as a dealer) can connect an operating tool 80 from outside the vehicle 10 and drive the pyrofuse device 21 from the operating tool 80 via the receiving unit 25. As a result, when disposing of or replacing the pyrofuse device 21, the user can drive the pyrofuse device 21 as needed, thereby preventing unintended operation of the pyrofuse device 21.

[0057] [Other embodiments] In the above embodiment, the pyrofuse device 21 is provided in the charging unit 70, but it may also be provided in another high-voltage electrical unit different from the charging unit 70. For example, the pyrofuse device 21 may be provided in the battery unit of the battery 30. Specifically, the pyrofuse device 21 may be provided within the battery unit in the power lines connected to the drive unit 50 or the charging unit 70.

[0058] Alternatively, the pyrofuse device 21 may be provided in the motor drive unit that constitutes the drive unit 50. Specifically, the pyrofuse device 21 may be provided in the motor drive unit on the power line connected to the battery 30.

[0059] Furthermore, in the above embodiment, the pyrofuse device 21 is provided inside the case 74 of the charging unit 70, but a separate case for housing the pyrofuse device 21 may be provided separately from the charging unit 70.

[0060] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The technical scope provided herein is defined by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0061] 10 Vehicle, 20 Power interruption device, 21 Pyro fuse device, 22 Control device, 23 Ground fault detection device, 24 Cutting member, 25 Receiving unit, 26 Microcontroller, 27a Case status confirmation unit, 27b Fault history confirmation unit, 27c Signal confirmation unit, 30 Battery, 40 Charging port, 50 Drive unit, 60 Tires, 70 Charging unit, 72 Booster device, 74 Case, 76 Opening / closing unit, 80 Operating tool.

Claims

1. A pyrofuse device is installed in the vehicle's power system and configured to shut off the power system when an abnormality in the vehicle is detected, A receiving unit that receives a signal from outside the vehicle requesting the operation of the pyrofuse device, A power interruption device comprising: a control device that drives the pyrofuse device when the receiving unit receives the signal.

2. The case further comprises the aforementioned pyrofuse device, The aforementioned case has an opening and closing section, The power interruption device according to claim 1, wherein the control device drives the pyrofuse device on the condition that the opening / closing part is closed.

3. The power interruption device according to claim 1 or 2, wherein the control device drives the pyrofuse device on the condition that there is a fault record indicating that an electrical unit provided in the power system is malfunctioning.

4. The aforementioned electrical unit is a charging unit that charges a battery mounted on the vehicle using power supplied from an external power source. The pyrofuse device is a power interruption device according to claim 3, provided in the charging unit.

5. The aforementioned electrical unit is a battery unit mounted on the vehicle, The pyrofuse device is provided in the battery unit, and is a power interruption device according to claim 3.

6. The aforementioned electrical unit is a motor drive unit mounted on the vehicle, The pyrofuse device is provided in the motor drive unit, as described in claim 3.

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