VEHICLE INTERRUPTION DEVICE

Abstract

A vehicle interrupting device is provided that enables a switch to be operated in a manner that improves its durability. An interrupting device (1) includes a first switch (33A) configured to switch a current path (11) between a conductive state and an interrupted state, the current path serving as a pathway for transmitting current supplied by a power supply unit (10). The interrupting device (1) includes a control unit (15) configured to perform deterioration determination processing, comparing a resistance value (R) and a resistance threshold value (Th1) of the first switch (33A).The control unit (15) determines that the first switch (33A) is in a deteriorated condition when the resistance value (R) is greater than or equal to the resistance threshold value (Th1) and notifies an external unit of the deteriorated condition.

Description

[0001] The present disclosure relates to a vehicle interrupt device. TECHNICAL BACKGROUND

[0002] Patent Document No. 1 discloses a power supply device that supplies a load with power stored in a battery by performing on / off control of a semiconductor switch by a semiconductor switch driving unit. PREVIOUSLY KNOWN TECHNICAL DOCUMENTSPATENT DOCUMENTS Patent Document No. 1: JP 2017 - 188 983 A Patent Document No. 2: JP 2017 - 225 307 A Patent Document No. 3: JP 2009 - 011 040 A OVERVIEW OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0003] As the output power of a power supply increases, the value of current flowing from the power supply to a load along a current path increases. Furthermore, the load on a switch or circuit breaker along the current path may increase, raising concerns that the switch or circuit breaker contacts are susceptible to wear. Therefore, there is an increased need to determine whether wear on the switch or circuit breaker contacts has increased and to operate the switch or circuit breaker based on the determination result.For example, there is a known method in which the upper limit of the number of opening / closing operations of the switch or circuit breaker is set in advance, and whether the switch or circuit breaker meets the performance requirements is determined by comparing the number of opening / closing operations of the switch or circuit breaker with the upper limit. However, in this method, a situation may arise in which it is determined that the switch or circuit breaker no longer meets the performance requirements when the number of opening / closing operations reaches the upper limit, even though the wear of the contacts of the switch or circuit breaker has not increased and the performance requirements are still met (that is, the switch is in a usable state).For this reason, there is a need for a method of operating a switch or circuit breaker in such a way that their longevity is improved.

[0004] The present disclosure has been made in view of the circumstances described above, and an object thereof is to provide a vehicle breaker device that enables a switch to be operated in a form in which its durability is improved. MEANS TO SOLVE THE TASK

[0005] A vehicle interrupt device according to the present disclosure is a vehicle interruption device comprising a switch configured to switch a current path between a conductive state and an interrupted state, the current path serving as a path for transmitting current originating from a power supply unit, wherein the interruption device comprises a control unit configured to perform deterioration determination processing in which a resistance value and a resistance threshold value of the switch are compared with each other, and the control unit determines that the switch is in a degraded condition when the resistance value is greater than or equal to the resistance threshold and notifies an external unit of the degraded condition. EFFECT OF THE INVENTION

[0006] According to the present disclosure, a switch can be operated in a form in which durability is improved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a circuit diagram illustrating a vehicle power supply system including a vehicle interrupting device according to Embodiment 1. Fig. 2 is a flowchart showing an example of control executed by a control unit of the vehicle interruption device according to Embodiment 1. Fig. Figure 3 is a graph showing temporal changes in the resistance value of a first switch. Fig. 4 is a circuit diagram showing positions where a voltage detection unit is connected to a low-potential side current path according to another embodiment. EMBODIMENTS OF THE INVENTION Description of embodiments of the present disclosure

[0007] First, aspects of the present disclosure are cited and described.

[0008] A vehicle interrupt device according to the present disclosure is

[0009] [1] A vehicle interruption device having a switch configured to switch a current path between a conductive state and an interruption state, the current path serving as a path to transfer current from a power supply unit. The interruption device has a control unit configured to perform a deterioration determination process in which a resistance value and a resistance threshold value of the switch are compared with each other. The control unit determines that the switch is in a deteriorated state when the resistance value is greater than or equal to the resistance threshold value, and notifies an external unit of the deteriorated state.

[0010] The vehicle circuit breaker according to [1] above can use the resistance value of the switch as an indicator for estimating the state of the switch. This makes it possible to determine, in a form suitable for the switch, whether the switch is in a deteriorated state or not, thereby easily improving the longevity of the switch. Furthermore, this configuration notifies an external unit of the deteriorated state, and therefore the external unit can easily take measures appropriate to the state of the switch. Here, the deteriorated state refers to a state in which the switch is worn compared to its state when originally provided in the circuit breaker, and its performance in switching the current path between the conductive state and the interrupted state is reduced.

[0011] [2] In the vehicle interruption device according to [1] above, the resistance value can be based on a potential difference between two sides of the switch when the switch is turned on and current flows through the current path, as well as on the current flowing through the current path.

[0012] The vehicle interruption device according to [2] above is configured to determine that the switch is in the deteriorated state when the resistance value, which is based on the potential difference between two sides of the switch when the switch is turned on and current flows through the current path, as well as on the current flowing through the current path, is greater than or equal to the threshold value. This makes it possible to determine in a manner suitable for the state of the switch whether the switch is in the deteriorated state, and thus the switch can be operated in a form in which its durability is improved.

[0013] [3] The vehicle disconnect device according to [2] above may further include a second switch configured to switch the current path between the conductive state and the disconnected state. For example, as a result of executing switching control in which the switch is turned on after the second switch, energization of the current path begins or a current of the current path increases. The control unit may execute deterioration determination processing in which the resistance value is compared with the resistance threshold value while the switching control is being executed.

[0014] In the vehicle circuit breaker according to [3] above, during switching control, the switch is turned on after the second switch, and therefore, an inrush current is likely to flow through the switch. Accordingly, the contacts of the switch are susceptible to wear (deterioration). According to this configuration, during switching control in which the contacts of the switch are susceptible to wear, the deterioration of the switch can be determined.

[0015] [4] In the vehicle interruption device according to [3] above, the current path may include a high-potential side current path and a low-potential side current path having a lower potential than the high-potential side current path. The second switch may be provided on one current path among the high-potential side current path and the low-potential side current path, and the switch may be provided on the other current path among the high-potential side current path and the low-potential side current path. The interruption device may further include a resistor and a third switch connected in series with the resistor, and has a parallel switching path in which the resistor and the third switch are connected in parallel with the switch.The switching control may be a control in which the energization of the current path is started by turning on the second switch and the third switch while the switch is off, and thereafter the switch is turned on while the second switch remains on.

[0016] In the vehicle circuit breaker according to [4] above, by energizing the current path in advance by turning on the second switch and the third switch, it is possible to cause current to flow through the current path while simultaneously suppressing an excessive increase in the peak value of the current flowing through the third switch through the resistance. After that, the switch is turned on while the second switch remains on. Accordingly, it is possible to suppress the peak of the inrush current flowing through the switch.

[0017] [5] In the vehicle circuit breaker according to [4] above, the control unit can detect a voltage between two terminals of the switch.

[0018] In the vehicle interruption device according to [5] above, it is possible to measure the resistance value of the switch in question more accurately.

[0019] [6] In the vehicle interruption device according to any one of [2] to [5] above, the control unit may execute the deterioration determination processing in which the resistance value is compared with the resistance threshold value when a magnitude of the current flowing through the current path is equal to or greater than a current threshold value.

[0020] The vehicle interruption device according to [6] above is arranged to compare the current flowing through the current path with the current threshold value, and it is therefore possible, for example, to narrow down the states of the current used to detect the resistance value to a state suitable for detecting the resistance value, thereby increasing the credibility of the calculated resistance value. Example 1 Design of the interruption device

[0021] A vehicle power supply system 100 as shown in Fig. 1 is a power supply system adapted to be installed in a vehicle, and includes a power supply unit 10 and an interrupter 1. The interrupter 1 includes a current path 11, a system main relay 33, a current detection unit 38, a voltage detection unit 39, and a control unit 15. The vehicle power supply system 100 has a configuration in which a load 35 can be supplied with power from the power supply unit 10 via the current path 11, which serves as a path through which power is transferred between the power supply unit 10 and the load 35.

[0022] The power supply unit 10 is a battery capable of supplying power to the load 35. For example, a composite battery or the like formed by a plurality of cells connected in series, such as lead-acid batteries, lithium-ion batteries, nickel-metal hydride batteries, or the like, can be used as the power supply unit 10.

[0023] The current path 11 includes a high-potential side current path 17 and a low-potential side current path 20. The high-potential side current path 17 is electrically connected to a high-potential side terminal of the power supply unit 10. The output voltage of the power supply unit 10 is applied to the high-potential side current path 17. The low-potential side current path 20 is electrically connected to a low-potential side terminal of the power supply unit 10. The low-potential side current path 20 has a lower potential than the high-potential side current path 17. The output voltage of the power supply unit 10 corresponds to the potential difference between the high-potential side terminal and the low-potential side terminal. The current path 11 is a path for transmitting current originating from the power supply unit 10 to the load 35. A fuse F is provided along the current path 17.The fuse F disconnects the high-potential side current path 17 when an excessive current flows through the high-potential side current path 17.

[0024] In the present disclosure, "electrically connected" preferably refers to a configuration in which objects to be connected are connected in a state in which the objects are conductively connected (a state in which current can flow through them), so that the potentials of the two objects are equal. However, the present disclosure is not limited to this configuration. For example, "electrically connected" may also refer to a configuration in which objects to be connected are connected in a state in which the objects can be conductively connected, while an electrical component is arranged between the two objects.

[0025] The load 35 is electrically connected to the high-potential side current path 17 and the low-potential side current path 20. The load 35 is an on-vehicle electronic component, and examples include products such as an electric motor component, an ECU, and an ADAS target component. Current output from the high-potential side terminal of the power supply unit 10 flows through the high-potential side current path 17, the load 35, the low-potential side current path 20, and the low-potential side terminal of the power supply unit 10, in that order.

[0026] The system main relay 33 is provided so as to be arranged on the high-potential side current path 17 and the low-potential side current path 20, respectively, between the power supply unit 10 and the load 35. The system main relay 33 includes a first switch 33A, a second switch 33B, and a parallel switching path 33C serving as a switch. Each of the first switch 33A and the second switch 33B is a relay switch having contacts that are physically switched between, for example, a state in which they are in contact with each other and a state in which they are spaced apart from each other. The parallel switching path 33C includes a resistor 33D and a third switch 33E connected in series with the resistor 33D. The third switch 33E is a relay switch having the same configuration as the first switch 33A and the second switch 33B. The third switch 33E is a so-called precharge relay.

[0027] The first switch 33A is provided on the low-potential side current path 20. The second switch 33B is provided opposite the power supply unit 10 on the high-potential side current path 17, with the fuse F interposed therebetween. The resistor 33D and the third switch 33E of the parallel switching path 33C are electrically connected to the low-potential side current path 20 so as to be parallel to the first switch 33A. The first switch 33A, the second switch 33B, and the third switch 33E are controlled by a predetermined control device C (hereinafter also referred to as control device C) to switch between an on-state and an off-state.By switching between the on and off states, the first switch 33A, the second switch 33B and the third switch 33E switch the current path 11 between a conductive state and an interrupted state.

[0028] The current detection unit 38 is provided such that it is arranged closer to the power supply unit 10 than the first switch 33A on the low-potential side current path 20. The current detection unit 38 includes, for example, a resistor and a differential amplifier and is configured to be capable of outputting, as the current value A, a value (specifically, an analog voltage corresponding to a value of the current flowing through the low-potential side current path 20) indicative of a current flowing through the low-potential side current path 20. That is, the current detection unit 38 detects, as the current value A, the state of the current flowing through the current path 11.

[0029] The voltage detection unit 39 is configured, for example, as a voltage detection circuit and is configured to be able to output a voltage value V corresponding to a potential difference between a terminal of the first switch 33A on the power supply unit 10 side and a terminal thereof on the load 35 side. That is, the voltage detection unit 39 detects the voltage state of the voltage of the current path 11 as the voltage value V. In other words, the voltage detection unit 39 detects, as the voltage value V, the potential difference between the terminals on both sides of the switch 33A, that is, the power supply unit 10 side and the load 35 side (the two sides are a side where the first switch 33A is supplied with power and a side where it outputs power).

[0030] The control unit 15 is configured, for example, as a microcomputer composed of a CPU, a ROM, a RAM, and a non-volatile memory, or the like, and includes a storage unit 15D. The control unit 15 includes a resistance value calculation unit 15A, a deterioration detection unit 15B, and a notification function unit 15C. The resistance value calculation unit 15A is configured to receive inputs of the current value A and the voltage value V from the current detection unit 38 and the voltage detection unit 39, respectively, and calculates and detects a resistance value R based on these values. For example, the resistance value R is obtained by dividing the voltage value V by the current value A. Based on the voltage value V from the voltage detection unit 39, the control unit 15 detects the voltage between the two terminals of the first switch 33A.

[0031] The deterioration detection unit 15B is configured to be capable of executing deterioration determination processing in which the resistance value R calculated by the resistance value calculation unit 15A is compared with a resistance threshold value Th1 stored in the storage unit 15D of the control unit 15. The deterioration detection unit 15B is configured to be capable of outputting a deterioration signal Sd when it is determined in the deterioration determination processing that the resistance value R is greater than or equal to the resistance threshold value Th1. The deterioration signal Sd is output when the first switch 33A is in a deteriorated state. That is, when the resistance value R is greater than or equal to the resistance threshold value Th1, the control unit 15 determines that the first switch 33A is in the deteriorated state.If it is determined in the deterioration determination processing that the magnitude of the resistance value R is smaller than the resistance threshold value Th1, the deterioration detection unit 15B does not output the deterioration signal Sd. In this case, the control unit 15 determines that the first switch 33A is not in the deteriorated state.

[0032] The notification function unit 15C is constituted by, for example, a communication device and is configured to perform notification by transmitting information to an external device (not shown) such as a battery management system (BMS) based on the deterioration signal Sd input from the deterioration detection unit 15B. Control in the control unit

[0033] Next, an example of control executed by the control unit 15 will be described with reference to Fig. 2 and so on. For example, when an ignition switch in a vehicle in which the vehicle power supply system 100 is installed is turned off, the first switch 33A and the second switch 33B of the system main relay 33, as well as the third switch 33E of the parallel switching path 33C, remain off. The current path 11 is now in an open state in which the supply of power from the power supply unit 10 to the load 35 is interrupted.

[0034] From this state, step S1 is first executed, which turns on the ignition switch. Next, when the processing proceeds to step S2, a power-on signal Son (see Fig. 1) is output from the control device C, and switching control is performed in which the first switch 33A, the second switch 33B, and the third switch 33E are turned on based on the turn-on signal Son. Specifically, in the switching control, the second switch 33B, the third switch 33E, and the first switch 33A are turned on in this order based on the turn-on signal Son output from the control device C. In other words, the switching control is control in which energization of the current path 11 is started by turning on the second switch 33B and the third switch 33E while the first switch 33A is off, and then the first switch 33A is turned on while the second switch 33B and the third switch 33E remain on. That is, the first switch 33A is turned on after the second switch 33B.It should be noted that the timing at which the turn-on signal Son is output from the control device C to the switches can be changed in various ways. That is, the control device C is capable of executing control other than switching control.

[0035] For example, the timings at which the second switch 33B, the third switch 33E, and the first switch 33A are turned on can be staggered by staggering the timings at which the turn-on signal Son is output from the controller C to the second switch 33B, the third switch 33E, and the first switch 33A, respectively. Note that the energization of the current path 11 begins when the second switch 33B and the third switch 33E have been turned on. Since the resistor 33D is connected in series with the third switch 33E, a current begins to flow through the current path 11 such that its magnitude gradually increases.

[0036] In addition, when the first switch 33A is turned on, the current path 11 enters a conductive state, allowing the load 35 to be supplied with power from the power supply unit 10. When the first switch 33A is turned on, an inrush current immediately flows through the first switch 33A. At this time, a current surge occurs, in which the current value A flowing through the current path 11 increases rapidly. Thus, as a result of the execution of the switching control, energization of the current path begins, or a current of the current path 11 increases. The inrush current continues to flow for a predetermined short time after the first switch 33A is turned on. After the predetermined short time has elapsed, the current flowing through the first switch 33A has stabilized to remain within a predetermined range lower than the magnitude of the inrush current.In this way, the first switch 33A is switched on and a current flows through the current path 11.

[0037] Then, when processing proceeds to step S3, the control unit 15 determines whether the predetermined short time has elapsed since the current path 11 was switched to the conductive state (since the first switch 33A was turned on). For example, the control unit 15 is provided with a time measuring function and is configured to be able to measure the predetermined short time since the current path 11 was switched to the conductive state. That the current path 11 has been switched to the conductive state can be determined, for example, from the extent to which the current value A changes within a predetermined time (the amount of change of the current value A per unit time). If the control unit 15 determines in step S3 that the predetermined short time has not yet elapsed since the current path 11 was switched to the conductive state (No in step S3), the processing of step S3 is repeated.

[0038] On the other hand, if the control unit 15 determines in step S3 that the predetermined short time has elapsed since the current path 11 switched to the conductive state (Yes in step S3), then processing proceeds to step S4. If processing proceeds to step S4, the control unit 15 determines whether a state continues in which the magnitude of the current value A is within the predetermined range. For example, the control unit 15 is configured to compare the current value A input from the current detection unit 38 with a current threshold value Th2 stored in the storage unit 15D of the control unit 15 and an upper-limit current threshold value Th3 that is greater than the current threshold value Th2.For example, the control unit 15 is configured to be able to determine, using its own time measurement function, whether a state in which the magnitude of the current value A is greater than or equal to the current threshold Th2 and less than the upper-limit current threshold Th3 has continued for a predetermined time (i.e., whether fluctuations in the current flowing through the current path 11 have settled). If the control unit 15 determines in step S4 that the state in which the magnitude of the current value A is greater than or equal to the current threshold Th2 and less than the upper-limit current threshold Th3 has not continued for the predetermined time (No in step S4), then the processing of step S4 is repeated.

[0039] If the control unit 15 determines in step S4 that the state in which the magnitude of the current value A is greater than or equal to the current threshold value Th2 and less than the upper-limit current threshold value Th3 has continued for the predetermined time (Yes in step S4), then the processing proceeds to step S5. If the processing proceeds to step S5, the control unit 15 obtains, in the resistance value calculation unit 15A, the resistance value R based on the current values ​​A and the voltage values ​​V input from the current detection unit 38 and the voltage detection unit 39, respectively. That is, the control unit 15 detects the resistance value R when the magnitude of the current value A flowing through the current path 11 is greater than or equal to the current threshold value Th2. After that, the processing proceeds to step S6.

[0040] If the processing continues with step S6, the control unit 15 in the deterioration detection unit 15B performs deterioration determination processing in which the resistance value R and the resistance threshold value Th1 are compared with each other. The control unit 15 performs deterioration determination processing in which the resistance value R, while the switching control is being performed by the control device C, is compared with the resistance threshold value Th1. For example, if it is determined in the deterioration determination processing that the magnitude of the resistance value R is greater than or equal to the resistance threshold value Th1 (Yes in step S6), then the processing continues with step S7, in which the deterioration signal Sd is output from the deterioration detection unit 15B.

[0041] In contrast, if it is determined in the deterioration determination processing that the magnitude of the resistance value R is smaller than the resistance threshold value Th1 (No in step S6), the deterioration signal Sd is not output. Thus, the control unit 15 executes the deterioration determination processing in which the resistance value R is compared with the resistance threshold value Th1 when the magnitude of the current flowing through the current path 11 is greater than or equal to the current threshold value Th2.Alternatively expressed, the control unit 15 performs a deterioration determination process in which the degree of deterioration of the first switch 33A is determined by comparing the resistance threshold value Th1 with the resistance value R of the first switch 33A, which is based on the voltage value V (the potential difference) between both sides of the first switch 33A when the first switch 33A is turned on and the current flow through the current path 11 and on the current value A flowing through the current path 11.

[0042] When the deterioration signal Sd is input into the notification function unit 15C, next, the notification function unit 15C performs an information transmission to an external device (not shown). That is, the notification function unit 15C of the control unit 15 notifies an external unit of the deteriorated state. In this way, the processing shown in Fig. 2 ends.

[0043] As the switching control is repeatedly performed by the control device C, the frequency of turn-on operations of the first switch 33A increases. This leads to progressive wear and oxidation of the contacts in the first switch 33A, whereby the resistance value R of the first switch 33A gradually increases. The control unit 15 determines the extent of deterioration of the first switch 33A by comparing the resistance threshold value Th1 with the resistance value R, which gradually increases with increasing turn-on frequency.

[0044] For example, when the frequency with which a large inrush current flows through the first switch 33A is high, the amount of temporal increase of the resistance value R of the first switch 33A is larger, as shown by a straight line S1 in Fig. 3. On the other hand, when the frequency with which a large inrush current flows through the first switch 33A is low, the amount of increase over time in the resistance value R of the first switch 33A is smaller, as shown by a straight line S2. T1 denotes the time at which the magnitude of the resistance value R reaches the resistance threshold value Th1 when the frequency with which a large inrush current flows through the first switch 33A is high (straight line S1), and T2 denotes the time at which the magnitude of the resistance value R reaches the resistance threshold value Th1 when the frequency with which a large inrush current flows through the first switch 33A is low (straight line S2). In addition, time T1 is earlier than time T2.

[0045] When the frequency with which a large inrush current flows through the first switch 33A is high (line S1), the magnitude of the resistance value R reaches the resistance threshold value Th1 earlier than when the frequency with which a large inrush current flows through the first switch 33A is low (line S2). That is, the interruption device 1 according to the present disclosure determines the degree of deterioration of the first switch 33A by considering the state of the contacts of the first switch 33A, thereby enabling the first switch 33A to operate in a manner that improves its durability.

[0046] Next, the effects of the present design are illustrated.

[0047] An interruption device 1 includes a first switch 33A configured to switch a current path 11 between a conductive state and an interruption state, the current path 11 serving as a path for transmitting power supplied from a power supply unit 10. The interruption device 1 includes a control unit 15 configured to perform deterioration determination processing in which a resistance value R and a resistance threshold value Th1 of the first switch 33A are compared. The control unit 15 determines that the first switch 33A is in a deteriorated state when the magnitude of the resistance value R is greater than or equal to the resistance threshold value Th1, and notifies an external unit of the deteriorated state.

[0048] The interruption device 1 can use the resistance value R of the first switch 33A as an indicator to estimate the state of the first switch 33A. This makes it possible to determine, in a manner suitable for the first switch 33A, whether the first switch 33A is in a deteriorated state, whereby the durability of the first switch 33A is improved in a simple manner. In addition, this configuration notifies an external unit of the deteriorated state and therefore the external unit can easily take measures appropriate for the state of the first switch 33A. Here, the deteriorated state refers to a state in which the first switch 33A is worn out compared to its state when it was originally provided in the interruption device 1 and its performance in switching the current path 11 between the conductive state and the interruption state is reduced.

[0049] In the interruption device 1, the resistance value R is based on a potential difference between two sides of the first switch 33A when the first switch 33A is turned on and current flows through the current path 11, as well as on the current flowing through the current path 11. This configuration determines that the first switch 33A is in the deteriorated state when the resistance value R, which is based on the potential difference between two sides of the first switch 33A when the first switch 33A is turned on and current flows through the current path 11, as well as on the current flowing through the current path 11, is greater than or equal to the resistance threshold value Th1. This makes it possible to determine in a form suitable for the state of the first switch 33A whether the first switch 33A is in the deteriorated state, and therefore the first switch 33A can be operated in a form in which its durability is improved.

[0050] The interruption device 1 further includes a second switch 33B configured to switch the current path 11 between the conductive state and the interrupted state. As a result of executing switching control in which the first switch 33A is turned on after the second switch 33B, current flow begins or a current increase occurs in the current path 11. The control unit 15 executes deterioration determination processing in which the resistance value R is compared with the resistance threshold value Th1 while the switching control is being executed.

[0051] During switching control, the first switch 33A is turned on after the second switch 33B, and therefore, an inrush current is likely to flow through the first switch 33A. Accordingly, the contacts of the first switch 33A are susceptible to wear (deterioration). According to this configuration, the deterioration of the first switch 33A can be determined during switching control in which the contacts of the first switch 33A are susceptible to wear.

[0052] In the interruption device 1, the current path 11 includes a high-potential-side current path 17 and a low-potential-side current path 20 having a lower potential than the high-potential-side current path 17. The second switch 33B is provided on the high-potential-side current path 17, and the first switch 33A is provided on the low-potential-side current path 20. The interruption device 1 further includes a resistor 33D and a third switch 33E connected in series with the resistor 33D, and a parallel switching path 33C on which the resistor 33D and the third switch 33E are connected in parallel with the first switch 33A.The switching control is a control in which the energization of the current path 11 is started by turning on the second switch 33B and the third switch 33E while the first switch 33A is turned off, and then turning on the first switch 33A while the second switch 33B and the third switch 33E remain turned on.

[0053] By starting the current path 11 to be energized in advance by turning on the second switch 33B and the third switch 33E, it is possible to cause a current to flow through the current path 11 and, at the same time, to suppress an excessive increase in the peak value of the current flowing through the third switch 33E through the resistor 33D. After that, the first switch 33A is turned on while the second switch 33B and the third switch 33E remain on. Accordingly, it is possible to suppress the peak of the inrush current flowing through the first switch 33A.

[0054] In the interruption device 1, the control unit 15 detects a voltage between two terminals of the first switch 33A. With this configuration, it is possible to detect the resistance value R of the respective first switch 33A more accurately.

[0055] In the interruption device 1, the control unit 15 performs deterioration determination processing in which the resistance value R is compared with the resistance threshold value Th1 when the magnitude of the current flowing through the current path 11 is greater than or equal to a current threshold value Th2. The interruption device 1 is configured to compare the current flowing through the current path 11 with the current threshold value Th2, and therefore, for example, it is possible to narrow down the states of the current used to detect the resistance value R to a state suitable for detecting the resistance value R, thereby increasing the credibility of the calculated resistance value R. Other embodiments

[0056] It should be understood that the presently disclosed embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is not limited to the presently disclosed embodiments, but is intended to include all modifications that come within the scope of the claims and the meaning and range of equivalents thereof.

[0057] Unlike in Embodiment 1, the positions where the voltage detection unit is connected can be any locations that have the same potential as the terminals on both sides of the first switch. As in Fig.4, the voltage detection unit 39 may be connected, for example, to positions closer to the power supply unit and closer to the load than the positions where the parallel switching path 33C is electrically connected to the low-potential side current path 20.

[0058] Unlike Embodiment 1, the notification function unit may be configured as a display unit, for example, a lamp of a display device, and may be configured to perform notification by displaying. The notification function unit may also be configured as an audio device such as a speaker and may be configured to perform notification using audio.

[0059] Unlike Embodiment 1, the resistance value calculation unit, the deterioration detection unit, and the notification function unit may be separately formed as individual information processing devices (individual microcomputers or the like).

[0060] Unlike Embodiment 1, the second switch may be provided on the low-potential side current path, and the first switch may be provided on the high-potential side current path. In this case, it is preferable that the parallel switching path is also provided on the high-potential side current path.

[0061] Unlike Embodiment 1, the control unit and the control device may be formed as a single microcomputer.

[0062] Unlike Embodiment 1, the deterioration determination processing may be executed after determining that the rate of increase of the current of the current path is less than or equal to a certain value. For example, a change amount Ki of the current of the current path per unit time is determined by Equation 1 below. Ki = | A1-A2 | / ΔT ... (Equation 1), where A1 is the current value A1 currently detected by the current detection unit, A2 is the current value A2 previously detected by the current detection unit, and ΔT is a time periodicity ΔT with which the current detection unit repeatedly detects the current value. The current value A2 may be stored, for example, in the RAM of the control unit. The change amount Ki is a value obtained by dividing the absolute value of the difference between the current value A1 and the current value A2 by the periodicity ΔT.For example, it may be determined that the fluctuations in the current flowing through the current path have settled when a state in which the change amount Ki is smaller than the threshold value stored in the storage unit of the control unit has continued for a predetermined time, and thereafter the resistance value of the first switch may be calculated.

[0063] Unlike Embodiment 1, it is possible to employ a configuration in which the third switch is not provided. In this case, the execution of the switching control causes a current surge in which the current value flowing through the current path increases rapidly.

[0064] Unlike Embodiment 1, it is possible to employ a configuration in which table data in which resistance values ​​corresponding to current values ​​and voltage values ​​are defined are stored in advance in the storage unit, and the resistance values ​​corresponding to the current values ​​and the voltage values ​​are extracted from the table data for use.

[0065] Unlike Embodiment 1, it is possible to employ a configuration in which table data in which resistance values ​​corresponding to the number of opening / closing operations of the switch are defined for each switch are stored in advance in the storage unit, and the resistance values ​​corresponding to the number of opening / closing operations of the switch are taken out from the table data for use.

[0066] It is assumed that the maximum value of the inrush current of a switch decreases as the resistance value of the switch increases. Therefore, unlike Embodiment 1, it is possible to adopt a configuration in which table data defining a resistance value corresponding to the maximum value of the inrush current of the switch for each switch is stored in advance in the storage unit, and the resistance value corresponding to the maximum value of the inrush current of the switch is retrieved from the table data for use. LIST OF REFERENCE SYMBOLS 1 interruption device 10 Power supply unit 11 Current path 15 Control unit 15A resistance value calculation unit 15B Deterioration detection unit 15C Notification functional unit 15D storage unit 17 high-potential side current path 20 low-potential current path 33 System main relays 33A first switch (switch) 33B second switch 33C parallel switching path 33D resistance 33E third switch 35 load 38 Current measuring unit 39 Voltage detection unit 100 vehicle power supply system A, A1, A2 current value C predetermined control device F fuse Ki change amount R resistance value Sd deterioration signal Son switch-on signal Th1 resistance threshold Th2 current threshold Th3 upper limit current threshold ΔT periodicity V voltage value QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2017 - 188 983 A

[0002] JP 2017 - 225 307 A

[0002] JP 2009 - 011 040 A

[0002]

Claims

[1] A vehicle interruption device comprising a switch configured to switch a current path between a conductive state and an interrupted state, the current path serving as a path for transmitting current originating from a power supply unit, wherein the interruption device comprises a control unit configured to perform deterioration determination processing in which a resistance value and a resistance threshold value of the switch are compared with each other, and the control unit determines that the switch is in a degraded condition when the resistance value is greater than or equal to the resistance threshold and notifies an external unit of the degraded condition. [2] The vehicle interrupting device according to claim 1, wherein the resistance value is based on a potential difference between two sides of the switch when the switch is turned on and current flows through the current path, and on the current flowing through the current path. [3] Vehicle interruption device according to claim 2, further comprising: a second switch configured to switch the current path between the conductive state and the interrupted state, wherein, as a result of an execution of a switching control in which the switch is switched on after the second switch, an energization of the current path begins or a current of the current path increases and the control unit executes the deterioration determination processing in which the resistance value is compared with the resistance threshold value while the switching control is being executed. [4] Vehicle interruption device according to claim 3, wherein the current path comprises a high-potential side current path and a low-potential side current path having a lower potential than the high-potential side current path, the second switch is provided on one current path of the high-potential side current path and the low-potential side current path, and the switch is provided on the other current path of the high-potential side current path and the low-potential side current path, the interruption device further comprises a resistor and a third switch connected in series with the resistor, and a parallel switching path on which the resistor and the third switch are connected in parallel with the switch, and the switching control is a control in which the energization of the current path is started by turning on the second switch and the third switch while the switch is off, and then the switch is turned on while the second switch remains on. [5] A vehicle interrupting device according to claim 4, wherein the control unit detects a voltage between two terminals of the switch. [6] The vehicle interruption device according to any one of claims 2 to 5, wherein the control unit executes the deterioration determination processing in which the resistance value is compared with the resistance threshold value when a magnitude of the current flowing through the current path is equal to or greater than a current threshold value.

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