JP6107679B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, and more particularly to a vehicle control device including a power supply device that supplies electric power to an electric load of the vehicle.

  In recent years, from the viewpoint of improving the fuel efficiency of a vehicle, an increasing number of vehicles adopt a so-called deceleration regeneration system that reduces the burden on the engine by generating power intensively when the vehicle is decelerated.

  Vehicles that employ a deceleration regeneration system can charge and discharge more rapidly than lead batteries, in addition to the widely used lead batteries, in order to charge large amounts of power generated during deceleration in a short time. In many cases, a simple capacitor is mounted (see, for example, Patent Document 1 below). Thus, by mounting two types of power storage devices having different characteristics, it is possible to secure a sufficiently large charge capacity while recovering the electric power generated during deceleration without waste.

  On the other hand, Patent Document 2 below discloses a vehicle power supply device that is not a combination of a lead battery and a capacitor, but also includes two types of power storage devices. Specifically, the power supply device for a vehicle disclosed in Patent Document 2 includes a lead battery and a lithium ion battery as power storage devices, a connection between the lead battery and an electric load, and a connection between the lithium ion battery and a starter (engine starter). And an intermittent switch. The switch is turned off (opened) when the starter is driven.

  If the switch is turned off when the engine is started, power is supplied to the starter only from the lead battery. At this time, since a large amount of power is consumed by the starter, the voltage of the lead battery is temporarily greatly reduced, but since the connection between the lead battery and the electric load is cut off by the switch off operation, The impact of lead-acid battery voltage drop does not reach electrical loads. The power consumption of the electric load is stably covered by the power supply from the lithium ion battery.

JP 2008-190323 A JP 2011-208599 A

  Here, in the configuration of Patent Document 2, for example, assuming a case where the vehicle is left for a long period of time, the voltage of the lithium ion battery at this time is considered to be reduced by natural discharge. If the engine is started in such a state, the amount of electric power supplied from the lithium ion battery to the electric load is insufficient, and the electric load may possibly malfunction. Of course, it is conceivable that a generator is driven by an engine and power is supplied from the generator to an electric load. However, in Patent Document 2, the generator and the lithium ion battery are always connected. Until the voltage recovers, the generated power is mainly used for charging the lithium ion battery, and eventually the power supplied to the electric load may be insufficient. This becomes more prominent when a capacitor is used instead of a lithium ion battery. That is, in a capacitor with good charge / discharge efficiency, the voltage of the capacitor greatly decreases as the vehicle is left for a long period of time. Therefore, the above situation that the power supplied to the electric load is insufficient when starting the engine is more likely to occur. .

  In addition, in order to execute deceleration regeneration control in which power generation is concentrated when the vehicle decelerates and the generated power is collected in a capacitor with good charge / discharge efficiency, the capacitor voltage is restored to the lead battery voltage as quickly as possible. It is necessary.

  The present invention has been made in view of the circumstances as described above, and can stably supply power to an electric load even when the voltage of the power storage device decreases due to long-term leaving of the vehicle, etc. And it aims at providing the control apparatus of the vehicle which can recover the voltage of an electrical storage apparatus at an early stage.

In order to solve the above-described problems, the present invention provides a vehicle control device including a power supply device that supplies electric power to an electric load of the vehicle, the generator driven by an engine to generate electric power, and the generator A first chargeable / dischargeable power storage device connected to the power generator, a second power storage device connected to the generator and capable of being charged / discharged more rapidly than the first power storage device, the generator, and the second power storage device A first interrupting means capable of interrupting the connection, a connection between the generator and the first power storage device, a second interrupting means capable of interrupting a connection between the generator and the electric load, and the first power storage device. A third on / off means capable of connecting / disconnecting with the second power storage device, a voltage detecting means for detecting the voltage of the second power storage device, an ignition switch detecting means for detecting the operation state of the ignition switch for starting the engine, The first intermittent hand A control means for controlling the second intermittent means and the third intermittent means, wherein the control means detects that the ignition switch is turned on by the ignition switch detecting means, and the voltage detecting means When it is detected that the voltage of the second power storage device is lower than a predetermined threshold, the first intermittent means is in a disconnected state, the second intermittent means is in a connected state, and the third intermittent means is in a connected state And the ignition switch detection means before the voltage detection means detects that the voltage of the second power storage device is greater than or equal to a predetermined reference value greater than the threshold during execution of the on- time charge control and the on-travel charge control. When it is detected that the ignition switch is turned off, the first intermittent means is connected, the second intermittent means is connected, and the first intermittent means is connected. When the charge control at the time of stopping that sets the intermittent means and the voltage detection means detects that the voltage of the second power storage device is equal to or higher than the reference value during the execution of the charge control at the time of stop. It is characterized by selectively executing stop-time discharge suppression control for turning off one intermittent means .

  According to the present invention, when the engine is started in a state where the voltage of the second power storage device has fallen below the threshold value, the first intermittent means is in the disconnected state and the second intermittent means is in the connected state. Therefore, it is prohibited to supply the generated power to the second power storage device having a low voltage (in other words, the power absorption amount is large), and much of the generated power can be supplied to the electric load and the first power storage device. As a result, the power consumption of the electric load can be covered without a shortage, and the malfunction of the electric load can be reliably prevented.

In addition, since the third intermittent means is connected, the power charged in the first power storage device is supplied to the second power storage device and the second power storage device is charged. Thus, the voltage of the second power storage device can be recovered immediately after the engine is started with the voltage of the second power storage device lowered. In addition, at that time, since the generated power is supplied to the first power storage device, the voltage of the first power storage device does not drop rapidly, and the deterioration of the first power storage device is also suppressed.
Further, according to the present invention, when the engine is stopped before the voltage of the second power storage device recovers to a reference value or more during execution of the traveling charge control, the first intermittent means is connected, Since the intermittent means is in the connected state and the third intermittent means is in the disconnected state, the power charged in the first power storage device is supplied to the second power storage device through the first intermittent means and the second intermittent means in the connected state, 2 Charging of the power storage device is continued after the engine is stopped. Then, when the voltage of the second power storage device is restored by this charging, it is not necessary to execute the above charging control when the engine is started next time. Therefore, the power generated by the generator is connected to the first connected state. It becomes possible to supply to the 2nd electrical storage apparatus which can be rapidly charged through an interruption means. This makes it possible to perform decelerating regenerative control that collects power and collects the generated power when the vehicle decelerates, reducing the burden on the engine in driving scenes other than during deceleration and effectively improving fuel efficiency. It will be possible to improve from the next driving cycle.
Furthermore, according to the present invention, when the voltage of the second power storage device recovers to a reference value or more during execution of the stop-time charge control, the first intermittent means is turned off, so that the second power storage device is charged. The generated electric power is prevented from flowing to the generator or the converter as a dark current while the engine is stopped. Therefore, the voltage drop of the second power storage device while the engine is stopped is suppressed.

  In the vehicle control apparatus of the present invention, preferably, a converter for stepping down the electric power charged in the second power storage device and supplying it to the electric load, and the second power storage device and the electric load are provided. A step-down line connected via the converter; and a bypass line connecting the second power storage device and the electrical load without going through the converter. The second intermittent means is provided in the bypass line. And when the voltage detection means detects that the voltage of the second power storage device is greater than or equal to a predetermined reference value greater than the threshold value during execution of the traveling charge control, The process shifts to normal control in which the first intermittent means is in the connected state, the second intermittent means is in the disconnected state, and the third intermittent means is in the disconnected state.

  According to this configuration, when the voltage of the second power storage device recovers to a reference value or more during execution of the traveling charge control, the first intermittent means is connected, the second intermittent means is disconnected, and the third intermittent means Therefore, the electric power charged in the second power storage device is stepped down by the converter through the step-down line and then supplied to the electric load. Moreover, the electric power generated by the generator is supplied to the second power storage device that can be rapidly charged through the first intermittent means in the connected state. On the other hand, the supply of power from the first power storage device to the second power storage device is stopped. This makes it possible to perform decelerating regenerative control that collects power and collects the generated power when the vehicle decelerates, reducing the burden on the engine in driving scenes other than during deceleration and effectively improving fuel efficiency. It is possible to improve from the current driving cycle (the period from the start of operation of the engine to the end of operation).

  In the vehicle control apparatus of the present invention, it is preferable that the control means is configured to perform the first intermittent operation when the ignition switch detecting means detects that the ignition switch is turned off during the execution of the normal control. The process proceeds to stop discharge suppression control in which the means is shut off.

  According to this configuration, when the engine is stopped during the execution of the normal control, the first intermittent means is turned off, so that the power charged in the second power storage device is generated as a dark current while the engine is stopped. It is prevented from flowing into the machine and the converter. Therefore, the voltage drop of the second power storage device while the engine is stopped is suppressed.

  In the vehicle control device of the present invention, preferably, the vehicle control device further includes a charging line that connects the first power storage device and the second power storage device, and the third interrupting means is provided in series with the resistor in the charging line. Yes.

  According to this configuration, during the execution of the traveling charge control, when power is supplied from the first power storage device to the second power storage device through the third intermittent means in the connected state and the second power storage device is charged, The amount of current is suppressed to a low level by the presence of resistance. For this reason, the voltage of the first power storage device is more reliably suppressed from rapidly decreasing.

  In the vehicle control device of the present invention, preferably, the power supply line connecting the generator and the second power storage device, and the electric power charged in the second power storage device are stepped down and supplied to the electric load. Converter, a bypass line for connecting the generator, the first power storage device and the electrical load, and connecting the second power storage device and the electrical load without going through the converter, and the second power storage A step-down line connecting the device, the first power storage device and the electric load via the converter, a point of the step-down line closer to the second power storage device than the converter, and the power supply line closer to the second power storage device A charging line for connecting a point to the charging line, wherein the first interrupting means is provided on the generator side of the power supply line with respect to the charging line and the second interrupting means is provided on the bypass line. The third disconnecting means is provided in the charging line.

  According to this configuration, during the execution of the traveling charge control, when power is supplied from the first power storage device to the second power storage device through the third intermittent means in the connected state and the second power storage device is charged, Electric power is supplied from the first power storage device to the second power storage device via the converter.

  In the vehicle control apparatus according to the present invention, preferably, the converter boosts a voltage with respect to power flowing in a direction opposite to the flow of power when the power is stepped down.

  According to this configuration, during the execution of the traveling charge control, when power is supplied from the first power storage device to the second power storage device through the third intermittent means in the connected state and the second power storage device is charged, Since the boosted power is supplied to the second power storage device, the voltage of the second power storage device can be recovered in a shorter time compared to a case where power that is not boosted is supplied.

  According to the present invention, even when the voltage of the power storage device decreases due to, for example, the vehicle being left for a long time, the power can be stably supplied to the electric load, and the voltage of the power storage device can be recovered early. There is provided a control device for a vehicle including a possible power supply device.

1 is a circuit diagram showing an electrical configuration of a vehicle including a power supply device according to an embodiment of the present invention. It is a block diagram which shows the control system of the said power supply device. It is a flowchart which shows the specific procedure of the control performed at the time of engine starting and a stop. It is explanatory drawing which shows the flow of electricity implement | achieved when control (charge control at the time of driving | running | working) of step S4-S6 in FIG. 3 is performed. It is explanatory drawing which shows the flow of electricity implement | achieved when control (normal control) of step S9-S11 in FIG. 3 is performed. It is explanatory drawing which shows the flow of electricity implement | achieved when control (charge control at the time of stop) of step S15-S17 in FIG. 3 is performed. It is a figure for demonstrating the modification of the said embodiment.

(1) Overall Configuration of Vehicle FIG. 1 is a circuit diagram showing an electrical configuration of a vehicle equipped with a power supply device according to an embodiment of the present invention (control in step S13 in FIG. 3 (stop discharge suppression control). (It is also an explanatory diagram in case that is executed). The vehicle shown in this figure is connected to an alternator 1 that generates power by generating power from a diesel engine (hereinafter also simply referred to as an engine) that is not shown in the engine room, and is electrically connected to the alternator 1. The battery 2 and the capacitor 3 that store the generated power, the DC / DC converter 4 that steps down the power generated by the alternator 1, the electric load 5 that includes various electrical components that consume power, and the engine that is driven when the engine is started. And a starter 6 for cranking the engine. The alternator 1 corresponds to a “generator” in the claims, the battery 2 corresponds to a “first power storage device” in the claims, and the capacitor 3 corresponds to a “second power storage device” in the claims. The DC / DC converter 4 corresponds to a “converter” in the claims.

  The alternator 1 generates power by rotating a rotor that rotates in conjunction with the output shaft of an engine in a magnetic field. The alternator 1 has a range of up to 25 V depending on the increase or decrease of the current applied to the field coil that generates the magnetic field. It is possible to adjust the generated power. The alternator 1 also includes a rectifier (not shown) that converts the generated AC power into DC power. That is, the electric power generated by the alternator 1 is converted into direct current by this rectifier and then transmitted to each part.

  The battery 2 is a lead storage battery having a nominal voltage of 12 V, which is a common power storage device for vehicles. Since such a battery 2 stores electrical energy by a chemical reaction, it is not suitable for rapid charge / discharge, but it has a characteristic that it can store a relatively large amount of power because it easily secures a charge capacity. There is.

  The capacitor 3 has a large capacity by connecting a plurality of electric double layer capacitors (EDLC), and can be charged up to 25V. Unlike the battery 2, the capacitor 3 stores electricity by physical adsorption of electrolyte ions, and therefore has a characteristic that it can be charged / discharged relatively quickly and has a low internal resistance.

  The DC / DC converter 4 is of a switching type in which a voltage is changed by ON / OFF (switching operation) of a built-in switching element. In the present embodiment, the DC / DC converter 4 is configured to switch the voltage of power supplied from the alternator 1 or the capacitor 3 side to the electric load 5 or the battery 2 side (that is, from the left side to the right side in the figure) by a switching operation. It has a function to step down the voltage, but other functions such as a function to allow power supply in the opposite direction (that is, from the right side to the left side in the figure) and to increase the voltage are provided. Not done.

  The alternator 1 and the capacitor 3 are connected to each other via a first power supply line 7 (corresponding to a “power supply line” in the claims). A second line (corresponding to a “step-down line” in the claims) 8 branches from the first line 7, and a DC / DC converter 4 is interposed in the middle of the second line 8. A third line 9 branches from the second line 8, and the battery 2 and the second line 8 are connected to each other via the third line 9. A fourth line 10 branches from the third line 9, and the starter 6 and the battery 2 are connected to each other via the fourth line 10.

  A capacitor cutoff relay 12 for interrupting the connection between the alternator 1 and the capacitor 3 is provided at a portion between the branch point of the first line 7 and the second line 8 and the capacitor 3. The capacitor cutoff relay 12 corresponds to the “first interrupting means” in the claims, and is in an on state (closed: connected state) that permits power supply from the alternator 1 to the capacitor 3 and in an off state that shuts off the power supply. It is possible to switch to (open: shut-off state).

  Further, a bypass line 11 branches from the first line 7 in parallel with the second line 8, and this bypass line 11 is connected to the middle part of the second line 8 located on the output side of the DC / DC converter 4. Has been. That is, the bypass line 11 connects the alternator 1 and the electric load 5 without using the DC / DC converter 4 and connects the battery 2 and the capacitor 3 without using the DC / DC converter 4. In order to intermittently connect these connections, the bypass line 11 is provided with a bypass relay 13. The bypass relay 13 corresponds to the “second intermittent means” in the claims, and is in an on state (closed: connected state) that permits power feeding through the bypass line 11 (bypassing the DC / DC converter 4), It is possible to switch to an off state (open: cut-off state) that cuts off the power supply.

  The electric load 5 includes an electric power steering mechanism 21 (hereinafter abbreviated as EPAS) for assisting a steering operation by a driver with a driving force of an electric motor or the like, an air conditioner 22, an audio 23, and the like. Yes. The electric loads such as the EPAS 21, the air conditioner 22, and the audio 23 are supplied to the first line via the second line 8 provided with the DC / DC converter 4 or the bypass line 11 provided with no DC / DC converter 4. 7 is connected.

  Furthermore, the electrical load 5 of the present embodiment includes a PTC heater 25 and a glow plug 26 in addition to the electrical load such as the EPAS 21 described above. The PTC heater 25 is a heater for heating the room by energization heating, and the glow plug 26 is a heater for warming the combustion chamber of the engine by energization heating when the engine (diesel engine in this embodiment) is cold started. is there. Although the glow plug 26 is connected to the battery 2 in parallel with the starter 6, the PTC heater 25 operates stably even at a maximum of 25 V, and is thus arranged on the alternator 1 and capacitor 3 side with respect to the DC / DC converter 4. Has been.

  In addition to the above, in the present embodiment, a charging line 14 that connects the battery 2 and the capacitor 3 is provided. The charging line 14 is interposed between a point on the third line 9 and a point closer to the capacitor 3 than the capacitor cutoff relay 12 in the first line 7. In addition, a charging relay 15 for connecting and disconnecting the battery 2 and the capacitor 3 to the charging line 14 is provided in series with the resistor 16. The charging relay 15 corresponds to the “third intermittent means” in the claims. The charging relay 15 is in an on state (closed: connected state) in which power supply from the battery 2 to the capacitor 3 through the charging line 14 is permitted, and the power supply is performed. It is possible to switch to an off state (open: cut-off state) for blocking.

(2) Control System FIG. 2 is a block diagram showing a control system of the vehicle power supply device of this embodiment. As shown in this figure, the alternator 1, the DC / DC converter 4, the starter 6, the capacitor cutoff relay 12, the bypass relay 13, the charging relay 15, the electric load 5 (EPAS 21, air conditioner 22, audio 23,. The component is connected to the controller 30 via various signal lines, and is controlled based on a command from the controller 30. The controller 30 is a microcomputer including a conventionally known CPU, ROM, RAM, and the like, and corresponds to “control means” in the claims.

  The controller 30 is connected to various sensors provided in the vehicle via signal lines. Specifically, the vehicle of this embodiment is provided with a voltage sensor SN1, an operation state detection means SN2, an ignition switch sensor SN3, and other switch detection means SN4, and information detected by these sensors is a controller. 30 are sequentially input.

  As shown in FIG. 1, the voltage sensor SN1 is a sensor that detects the voltage of the capacitor 3 (capacitor voltage), and corresponds to “voltage detection means” in the claims.

  The driving state detection means SN2 is a generic term for sensors that detect physical quantities related to the state of the vehicle or engine. For example, a vehicle speed sensor that detects the traveling speed of the vehicle, an engine rotation speed sensor that detects the rotation speed of the engine, and an accelerator pedal. And an accelerator / brake sensor that detects an operation amount or an operation force of the brake pedal. Based on the input information from the driving state detection means SN2, the controller 30 can obtain information such as whether the vehicle is decelerating or accelerating and the degree of deceleration / acceleration.

  The ignition switch sensor SN3 is a sensor for detecting an operation state of an unillustrated ignition switch operated by a driver when starting or stopping the engine, and corresponds to “ignition switch detection means” in the claims. .

  The other switch detection means SN4 is a generic term for sensors that detect operation states of switches other than the ignition switch, and includes, for example, sensors that detect operation states of operation switches such as an air conditioner and an audio.

  Based on the input information from each of the sensors SN1 to SN4, the controller 30 generates power generated by the alternator 1, a step-down operation by the DC / DC converter 4, driving / stopping the electric load 5 and the starter 6, relays 12, 13 , 15 on / off operation and the like are controlled. Hereinafter, a specific example of the control operation by the controller 30 will be described in detail.

(3) Control operation The vehicle power supply device of the present embodiment can execute so-called deceleration regeneration control in which power generation is concentrated when the vehicle is decelerated. For this reason, during traveling of the vehicle, each part of the power supply device is controlled by the controller 30 as follows.

  At the time of deceleration of the vehicle, power generation by the alternator 1 is actively performed, and generated power of 25 V at maximum is generated. The electric power generated by the alternator 1 is stepped down to 12V by the DC / DC converter 4 and then supplied to the electric load 5. Further, surplus power exceeding the power consumption in the electric load 5 is supplied to the capacitor 3 and charged. Since the capacitor 3 can be rapidly charged as already described, surplus power is efficiently recovered by the capacitor 3. However, when the capacitor 3 is already in a fully charged state (25 V), the capacitor 3 cannot be charged any more, so surplus power is sent to charge the battery 2.

  On the other hand, in a driving scene other than when the vehicle is decelerating, power generation by the alternator 1 is suppressed as much as possible in order to reduce the resistance applied from the alternator 1 to the engine. For example, when power generation by the alternator 1 is not performed, power consumption in the electric load 5 is mainly provided by charging power of the capacitor 3. In other words, the maximum 25 V power charged in the capacitor 3 is stepped down to 12 V by the DC / DC converter 4 and then supplied to the electric load 5. However, when the capacitor voltage is not sufficiently high, or when the power consumption at the electric load 5 is relatively large, the power consumption at the electric load 5 cannot be covered only by the charging power of the capacitor 3. Therefore, in such a case, the power generation by the alternator 1 is performed to the minimum necessary, and the power generated by the alternator 1 is used, and the power discharged from the battery 2 is also used as necessary. . By such control, the charging power of the capacitor 3 while the vehicle is traveling is always kept above a certain level. In the present embodiment, charging / discharging of the capacitor 3 is controlled so that the capacitor voltage falls within the range of 12 to 25V.

  As described above, in this embodiment, power is supplied mainly from the alternator 1 to the electric load 5 through the DC / DC converter 4 when the vehicle is decelerated, and from the capacitor 3 through the DC / DC converter 4 except when the vehicle is decelerated. Electric power is supplied to the load 5. For this reason, during traveling of the vehicle, in principle, power feeding through the bypass line 11 is not performed, and the capacitor 3 is not disconnected from the first line 7. For this reason, as shown in FIG. 5, the bypass relay 13 is always maintained in the disconnected state, and the capacitor disconnecting relay 12 is always maintained in the connected state.

  However, when the engine is started after the vehicle has been left for a long time, it is assumed that the capacitor voltage is greatly reduced due to the spontaneous discharge of the capacitor 3. Under such circumstances, when the normal relay operation described above is executed (that is, when the bypass relay 13 is turned off and the capacitor cutoff relay 12 is turned on), the following problems occur.

  If the engine is started while the capacitor voltage is greatly reduced and the capacitor cutoff relay 12 is kept connected, even if power generation by the alternator 1 is started immediately thereafter, the generated power is naturally low in voltage. Since power is supplied to the capacitor 3, almost no power is supplied from the alternator 1 to the electric load 5. For this reason, until the capacitor 3 is fully charged and its voltage recovers (for example, until it reaches 12 V or more) (about 15 to 60 seconds), most of the power consumption in the electric load 5 is the battery 2. It will be covered by the discharge power from. At this time, since the voltage of the battery 2 (battery voltage) decreases with the large current consumption when the starter 6 is driven, the power supplied from the battery 2 to the electric load 5 must be reduced. Under such circumstances, when an electric load with relatively high power consumption, such as an EPAS (Electric Power Steering Mechanism) 21, for example, operates, the battery voltage supplied to each electric load further decreases. In the worst case, a malfunction or malfunction may occur, and the voltage of the power supplied to the controller 30 may be lower than the necessary minimum voltage (the lower limit voltage necessary for normal operation of the microcomputer). There is.

  Therefore, in order to prevent such a problem, in the present embodiment, the following control is performed when the engine is started and stopped.

  FIG. 3 is a flowchart showing a specific procedure of control performed by the controller 30 when the engine is started and stopped.

  That is, in step S1, the controller 30 determines whether or not the ignition switch has been turned on based on the input information from the ignition switch sensor SN3 (that is, whether or not the driver has performed an operation to start the engine). As a result, in the case of YES, the controller 30 starts the engine by driving the starter 6 in step S2.

  Next, in step S3, the controller 30 determines whether or not the capacitor voltage is less than 8 V (corresponding to a “predetermined threshold” in the claims) based on input information from the voltage sensor SN1. Here, the state in which the capacitor voltage is less than 8 V is a state in which the capacitor voltage is greatly reduced (a state in which the voltage is lower than the battery voltage) due to the vehicle being left for a long period of time.

  As a result, in the case of YES, in Steps S4 to S6, the controller 30 executes running charge control in which the capacitor disconnecting relay 12 is disconnected, the bypass relay 13 is connected, and the charging relay 15 is connected. In step S7, the controller 30 applies current to the field coil of the alternator 1 to cause the alternator 1 to generate power. However, the alternator 1 generates electricity at 12 V in order to protect the electric load 5 and the battery 2 during execution of the on-running charging control.

  When the running charging control is executed, as shown in FIG. 4, the electric power generated by the alternator 1 passes through the bypass relay 13 in a connected state (that is, bypasses the DC / DC converter 4) and the electric load 5. And supplied to the battery 2. On the other hand, since the capacitor cutoff relay 12 is in the cutoff state, the power generated by the alternator 1 is not supplied to the capacitor 3. Further, since the charging relay 15 is in a connected state, a current flows from the battery 2 to the capacitor 3 via the charging line 14, and the capacitor 3 is charged by the battery 2. At this time, since the generated power is supplied to the battery 2 by the alternator 1, a sudden drop in the battery voltage is also suppressed.

  Next, in step S8, the controller 30 determines whether or not the capacitor voltage has become equal to or higher than 12V (corresponding to the “predetermined reference value” in the claims) in accordance with the execution of the running charge control. In the case of NO, the process proceeds to step S9, and in the case of NO, the process proceeds to step S14. Here, the state where the capacitor voltage is 12 V or more is a state where the capacitor voltage is recovered to the battery voltage.

  In Steps S9 to S11, the controller 30 executes normal control in which the capacitor cutoff relay 12 is in the connected state, the bypass relay 13 is in the disconnected state, and the charging relay 15 is in the disconnected state.

  When this normal control is executed, as shown in FIG. 5, electric power is supplied from the capacitor 3 to the electric load 5 through the DC / DC converter 4 except when the vehicle is decelerating. Electric power is supplied to the electric load 5 through the DC converter 4. The alternator 1 returns to normal regenerative power generation of 25 V at the maximum during execution of this normal control. In this normal control, the current flows from the battery 2 to the capacitor 3 via the charging line 14, that is, the charging of the capacitor 3 by the battery 2 is stopped.

  Next, in step S12, the controller 30 determines whether or not the ignition switch has been turned off based on the input information from the ignition switch sensor SN3 (that is, whether or not the driver has performed an operation to stop the engine). As a result, in the case of YES, the controller 30 executes stop-time discharge suppression control that sets the capacitor cutoff relay 12 in the cutoff state in step S13.

  When the stop-time discharge suppression control is executed, the capacitor 3 is disconnected from the alternator 1, the battery 2, the DC / DC converter 4, the electrical load 5, the starter 6, and the PTC heater 25 as shown in FIG. Therefore, it is avoided that dark current flows from the capacitor 3 to these devices while the engine is stopped. Therefore, it is possible to suppress the capacitor voltage from decreasing while the engine is stopped.

  If the answer is NO in step S3, the controller 30 proceeds to step S9 and immediately executes normal control. If NO in step S12, the process returns to step S9 to continue normal control.

  On the other hand, if it is determined as NO in step S8 and the process proceeds to step S14, the controller 30 determines whether or not the ignition switch is turned off based on the input information from the ignition switch sensor SN3 in step S14 (that is, the driver). If YES, the process proceeds to step S15. If NO, the process returns to step S4 to continue the charge control during travel.

  In Steps S15 to S17, the controller 30 performs charge control at stop when the capacitor cutoff relay 12 is in the connected state, the bypass relay 13 is in the connected state, and the charging relay 15 is in the disconnected state.

  When the stop-time charging control is executed, as shown in FIG. 6, the power charged in the battery 2 is supplied to the capacitor 3 through the bypass relay 13 and the capacitor cutoff relay 12 in the connected state, and the capacitor 3 It is charged by the battery 2.

  Next, in step S18, the controller 30 determines whether or not the capacitor voltage has become equal to or higher than 12V (corresponding to the “predetermined reference value” in the claims) in accordance with the execution of the stop-time charge control. In this case, the process proceeds to step S13, and the stop-time discharge suppression control for turning off the capacitor disconnect relay 12 is executed. If NO, the process returns to step S15 and the stop-time charge control is continued.

(4) Operation As described above, in the present embodiment, a vehicle control device including a power supply device that supplies electric power to the electric load 5 of the vehicle includes an alternator 1 that is driven by an engine to generate electric power, and the alternator 1 described above. A connected chargeable / dischargeable battery 2, a capacitor 3 connected to the alternator 1 and capable of charging / discharging more rapidly than the battery 2, and a capacitor cutoff relay capable of intermittently connecting the alternator 1 and the capacitor 3. 12, a bypass relay 13 that can intermittently connect the alternator 1 and the battery 2, and a connection between the alternator 1 and the electrical load 5, and a charge relay 15 that can intermittently connect the battery 2 and the capacitor 3. , The operation state of the voltage sensor SN1 for detecting the capacitor voltage and the ignition switch for starting the engine is detected. An ignition switch sensor SN3 to be output, and a controller 30 for controlling the capacitor cutoff relay 12, the bypass relay 13, and the charging relay 15. The controller 30 is turned on by the ignition switch sensor SN3. Is detected and the voltage sensor SN1 detects that the capacitor voltage is less than 8V (YES in step S3), the capacitor disconnect relay 12 is disconnected, the bypass relay 13 is connected, The charge control at the time of travel which makes the charge relay 15 a connection state is performed (step S4-S6, FIG. 4).

  According to this configuration, when the engine is started with the capacitor voltage lowered to less than 8 V, the capacitor cutoff relay 12 is set to the cutoff state and the bypass relay 13 is set to the connected state. Therefore, the electric power generated by the alternator 1 is a voltage. Supply to the low capacitor (in other words, the power absorption amount is large) is prohibited, and much of the generated power can be supplied to the electric load 5 and the battery 2. Thereby, the power consumption in the electric load 5 can be covered without shortage, and malfunction of the electric load 5 can be reliably prevented from occurring.

  At the same time, since the charging relay 15 is connected, the power charged in the battery 2 is supplied to the capacitor 3 and the capacitor 3 is charged. As a result, the capacitor voltage can be recovered immediately after the engine is started with the capacitor voltage lowered. In addition, since the generated power is supplied to the battery 2 at that time, the battery voltage does not drop rapidly, and the deterioration of the battery 2 is also suppressed.

  In this way, the power generated by the alternator 1 is prohibited from flowing to the capacitor 3 and allowed to flow to the electric load 5 and the battery 2, and the power consumption of the electric load 5 is reduced by the generated power of the alternator 1. Since the battery can be covered, the battery 2 can be reduced in size, and the vehicle power supply device can be mounted on a small vehicle.

  In the present embodiment, the DC / DC converter 4 for reducing the power charged in the capacitor 3 and supplying it to the electric load 5, and the capacitor 3 and the electric load 5 are connected to the DC / DC converter 4. And a bypass line 11 for connecting the capacitor 3 and the electric load 5 without the DC / DC converter 4, and the bypass relay 13 is connected to the bypass line 11. When the voltage sensor SN1 detects that the capacitor voltage is 12 V or more during execution of the traveling charge control (YES in step S8), the controller 30 is provided with the capacitor cutoff relay. 12 is normally connected, the bypass relay 13 is disconnected, and the charging relay 15 is disconnected. Shifts control (step S9 to S11, FIG. 5).

  According to this configuration, when the capacitor voltage recovers to 12 V or more during the running charge control, the capacitor disconnecting relay 12 is in the connected state, the bypass relay 13 is in the disconnected state, and the charging relay 15 is in the disconnected state. The electric power charged in the capacitor 3 is stepped down by the DC / DC converter 4 through the second line 8 and then supplied to the electric load 5. Further, the electric power generated by the alternator 1 is supplied to the capacitor 3 that can be rapidly charged through the connected capacitor cutoff relay 12. On the other hand, the supply of power from the battery 2 to the capacitor 3 is stopped. This makes it possible to perform decelerating regenerative control that collects power and collects the generated power when the vehicle decelerates, reducing the burden on the engine in driving scenes other than during deceleration and effectively improving fuel efficiency. Improvements are possible from the current driving cycle.

  In the present embodiment, the controller 30 operates the ignition switch to be turned off by the ignition switch sensor SN3 before the voltage sensor SN1 detects that the capacitor voltage is 12 V or more during execution of the running charge control. If it is detected (YES in step S14), the control proceeds to stop-time charging control in which the capacitor disconnecting relay 12 is connected, the bypass relay 13 is connected, and the charging relay 15 is disconnected ( Steps S15 to S17, FIG. 6).

  According to this configuration, when the engine is stopped before the capacitor voltage is recovered to 12 V or more during the running charge control, the capacitor cutoff relay 12 is connected, the bypass relay 13 is connected, 15 is in the cut-off state, the electric power charged in the battery 2 is supplied to the capacitor 3 through the connected capacitor cut-off relay 12 and the bypass relay 13, and the capacitor 3 is continuously charged even after the engine is stopped. When the capacitor voltage is restored by this charging, it is not necessary to execute the above-described charging control when the engine is started next time, so that the generated power in the alternator 1 is rapidly supplied through the connected capacitor cutoff relay 12. It becomes possible to supply to the chargeable capacitor 3. This makes it possible to perform decelerating regenerative control that collects power and collects the generated power when the vehicle decelerates, reducing the burden on the engine in driving scenes other than during deceleration and effectively improving fuel efficiency. It will be possible to improve from the next driving cycle.

  In the present embodiment, the controller 30 detects that the ignition switch is turned off by the ignition switch sensor SN3 during execution of the normal control (YES in step S12), the capacitor cutoff relay 12 The process proceeds to the stop-time discharge suppression control in which the operation is stopped (step S13, FIG. 1).

  According to this configuration, when the engine is stopped during the execution of the normal control, the capacitor cutoff relay 12 is turned off, so that the electric power charged in the capacitor 3 becomes a dark current while the engine is stopped. It is possible to prevent the DC / DC converter 4 from flowing. As a result, a decrease in the capacitor voltage while the engine is stopped is suppressed.

  In the present embodiment, the controller 30 detects the capacitor cutoff relay when the voltage sensor SN1 detects that the capacitor voltage is 12 V or more during execution of the stop-time charge control (YES in step S18). Then, the process proceeds to stop-time discharge suppression control in which 12 is shut off (step S13).

  According to this configuration, when the capacitor voltage recovers to 12 V or more during execution of the stop-time charge control, the capacitor cutoff relay 12 is turned off, so that the power charged in the capacitor 3 is darkened while the engine is stopped. Current flowing through the alternator 1 and the DC / DC converter 4 is prevented. As a result, a decrease in the capacitor voltage while the engine is stopped is suppressed.

  In the present embodiment, a charging line 14 that connects the battery 2 and the capacitor 3 is further provided, and the charging relay 15 is provided in series with the resistor 16 in the charging line 14.

  According to this configuration, when power is supplied from the battery 2 to the capacitor 3 through the connected charging relay 15 and the capacitor 3 is charged during the running charge control, the current amount of the resistor 16 is reduced. Suppressed by its presence. As a result, the battery voltage is more reliably suppressed from rapidly decreasing.

(5) Modification FIG. 7 shows a modification of the above embodiment. In this modification, the arrangement of the charging line 14 is different from that in FIG. That is, in the above embodiment, the charging line 14 is interposed between the point on the third line 9 and the point closer to the capacitor 3 than the capacitor cutoff relay 12 in the first line 7. On the other hand, in this modification, the charging line 14 is closer to the capacitor 3 than the DC / DC converter 4 in the second line 8 and is closer to the capacitor 3 than the capacitor cutoff relay 12 in the first line 7. It is interposed between.

  According to this configuration, as shown in FIG. 7, during the execution of the running charge control, when power is supplied from the battery 2 to the capacitor 3 through the connected charging relay 15 and the capacitor 3 is charged, Electric power is supplied from the battery 2 to the capacitor 3 via the DC / DC converter 4 (see FIG. 4).

  In this case, the DC / DC converter 4 has a function of stepping down the voltage of electric power supplied from the alternator 1 or the capacitor 3 side to the electric load 5 or the battery 2 side (that is, from the left side to the right side in the figure) by a switching operation. , Has a function of permitting the supply of electric power in the opposite direction (that is, from the right side to the left side in the figure).

  Further, the DC / DC converter 4 boosts the voltage with respect to the power flowing in the opposite direction (that is, from the right side to the left side in the figure) when the power is stepped down (that is, from the left side to the right side in the figure). It may have a function.

  Then, as shown in FIG. 7, during the running charge control, the voltage is boosted when power is supplied from the battery 2 to the capacitor 3 through the connected charging relay 15 to charge the capacitor 3. Since the electric power is supplied to the capacitor 3, the capacitor voltage can be recovered in a short time compared to the case where the electric power not boosted is supplied.

  In the above-described embodiment, the capacitor 3 including a plurality of electric double layer capacitors (EDLC) is used as the power storage device (second power storage device described in the claims) that can be charged and discharged more rapidly than the battery 2. It is also possible to use a power storage device other than the capacitor 3 as the second power storage device. One example is a lithium ion capacitor. Unlike the electric double layer capacitor, the lithium ion capacitor further improves the energy density by using a carbon-based material capable of electrochemically occluding lithium ions as the negative electrode. It is also called a hybrid capacitor because the charge / discharge principle is different (a chemical reaction is used in combination).

  In the above embodiment, the case where the present invention is applied to a vehicle equipped with a diesel engine has been described as an example. However, the present invention is naturally applied to a vehicle equipped with an engine other than a diesel engine (for example, a gasoline engine). Can be applied to.

  Further, in the above embodiment, the alternator 1 is used as a generator that generates power by obtaining power from the engine. However, not only power generation but also torque assist (operation for adding torque to the output shaft of the engine) can be performed. A possible electric motor (motor generator) may be used as the generator. That is, the present invention can be applied not only to a conventional vehicle in which only an engine is a power source, but also to a hybrid vehicle using both an engine and an electric motor.

  The resistor 16 may not be provided. Due to the presence of the resistor 16, it is possible to adjust the time required for charging the capacitor 3 during the charge control during travel and the charge control during stop. For example, if the charging time is lengthened, the wire harness constituting the charging line 14 or the like can be made thinner.

  In the stop-time charging control of FIG. 6, the capacitor cutoff relay 12 may be in a cutoff state, the bypass relay 13 may be in a cutoff state, and the charging relay 15 may be in a connected state. Thereby, the electric power charged in the battery 2 is supplied to the capacitor 3 through the charging line 14 through the charging relay 15 in the connected state, and the capacitor 3 is charged by the battery 2. In this case, it is preferable that there is no resistor 16.

1 Alternator (generator)
2 Battery (first power storage device)
3 Capacitor (second power storage device)
4 DC / DC converter (converter)
5 Electric load 6 Starter 7 First line (feed line)
8 Second line (step-down line)
9 Third line 10 Fourth line 11 Bypass line 12 Capacitor cutoff relay (first intermittent means)
13 Bypass relay (second intermittent means)
14 Charging line 15 Charging relay (third intermittent means)
16 resistance 30 controller (control means)
SN1 voltage sensor (voltage detection means)
SN3 ignition switch sensor (ignition switch detection means)

Claims (6)

A vehicle control device including a power supply device that supplies electric power to an electric load of the vehicle,
A generator driven by an engine to generate electricity;
A chargeable / dischargeable first power storage device connected to the generator;
A second power storage device connected to the generator and capable of charging and discharging more rapidly than the first power storage device;
A first intermittent means capable of intermittently connecting the generator and the second power storage device;
A second intermittent means capable of intermittently connecting the generator and the first power storage device and connecting the generator and the electrical load;
A third intermittent means capable of intermittently connecting the first power storage device and the second power storage device;
Voltage detecting means for detecting the voltage of the second power storage device;
An ignition switch detecting means for detecting an operation state of the ignition switch for starting the engine;
Control means for controlling the first intermittent means, the second intermittent means, and the third intermittent means,
The control means includes
When the ignition switch detecting means detects that the ignition switch is turned on, and the voltage detecting means detects that the voltage of the second power storage device is less than a predetermined threshold, the first intermittent means A charge control during traveling, wherein the second intermittent means is connected, the third intermittent means is connected ,
The ignition switch is turned off by the ignition switch detection means before the voltage detection means detects that the voltage of the second power storage device is greater than or equal to a predetermined reference value greater than the threshold value during execution of the running charge control. When it is detected that the first intermittent means is in a connected state, the second intermittent means is in a connected state, and the third intermittent means is in a disconnected state;
Stop discharge suppression control that shuts off the first intermittent means when the voltage detection means detects that the voltage of the second power storage device is equal to or higher than the reference value during execution of the stop charge control. When,
Is selectively executed. The vehicle control apparatus characterized by the above-mentioned. The vehicle control device according to claim 1,
A converter for stepping down the electric power charged in the second power storage device and supplying the electric load to the electric load;
A step-down line that connects the second power storage device and an electrical load via the converter;
A bypass line that connects the second power storage device and the electrical load without going through the converter;
The second intermittent means is provided in the bypass line,
The control means is configured to detect the first intermittent means when the voltage detection means detects that the voltage of the second power storage device is equal to or higher than a predetermined reference value greater than the threshold during execution of the traveling charge control. A control apparatus for a vehicle, wherein the control is shifted to a normal control in which the second intermittent means is disconnected and the third intermittent means is disconnected. The vehicle control device according to claim 2,
When the ignition switch detecting means detects that the ignition switch is turned off during the execution of the normal control, the control means shifts to a stop-time discharge suppression control in which the first intermittent means is cut off. A control apparatus for a vehicle. The vehicle control device according to any one of claims 1 to 3 ,
A charge line connecting the first power storage device and the second power storage device;
The vehicle control device, wherein the charging line is provided with the third intermittent means in series with a resistor. The vehicle control device according to any one of claims 1 to 4 ,
A power supply line connecting the generator and the second power storage device;
A converter for stepping down the electric power charged in the second power storage device and supplying the electric load to the electric load;
A bypass line for connecting the generator to the first power storage device and the electrical load, and connecting the second power storage device and the electrical load without going through the converter;
A step-down line that connects the second power storage device, the first power storage device, and an electrical load via the converter;
A charge line that connects a point closer to the second power storage device than the converter of the step-down line and a point closer to the second power storage device of the power feeding line;
The first intermittent means is provided on the generator side of the power supply line with respect to the charging line, the second intermittent means is provided on the bypass line, and the third intermittent means is provided on the charging line. A control apparatus for a vehicle. The vehicle control device according to claim 5 ,
The above-mentioned converter boosts a voltage with respect to electric power that flows in a direction opposite to the flow of the electric power when the electric power is stepped down.

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