JP7159805B2 - vehicle power supply controller - Google Patents

Description

TECHNICAL FIELD The present invention relates to a power control device provided in a vehicle having a power generation device that is driven by an engine to generate power.

2. Description of the Related Art Conventionally, vehicles are equipped with a plurality of batteries to supply electric power to various electric devices.

For example, in Patent Document 1, a vehicle is provided in which a large-capacity lithium battery is provided in addition to a lead battery, and electric power can be supplied from the lead battery and the lithium battery to a starter for driving the engine. It is Specifically, in this vehicle, the starter is connected to a switching relay that switches the connection destination of the starter between the lithium battery and the starter. The switching relay and the lead battery are connected, and the switching relay and the lithium battery are connected via a relay provided in the battery. Then, by connecting the starter to the lead battery by the switching relay, power is supplied from the lead battery to the starter, and with the relay provided in the battery closed, the switching relay connects the starter to the lithium battery. By using a battery, power is supplied to the starter from the lithium battery.

Japanese Patent Application Laid-Open No. 2004-190626

A storage battery and various electrical devices mounted on a vehicle must be connected when the engine is started so that these electrical devices can be used immediately upon demand. In other words, it is desired that the relays provided between the storage battery and various electric devices are closed early when the engine is started. However, if the relay operates while the engine is not rotating, the operating noise may be transmitted to the passenger, which may make the passenger feel uncomfortable.

SUMMARY OF THE INVENTION The present invention has been made in view of the circumstances as described above, and is a vehicle power supply control apparatus capable of improving the comfort of the user while appropriately connecting a storage battery to an electric device connected thereto. intended to provide

In order to solve the above-mentioned problems, the present invention includes a storage battery and an electric device that is activated by power supplied from the storage battery, and is driven by an engine to generate power and supply the generated power to the storage battery. a first relay and a second relay arranged in parallel between the power generation device and the storage battery for connecting and disconnecting the power generation device and the storage battery, respectively; a control means for controlling a relay, wherein the first relay is a relay made of a semiconductor and has no contact; the second relay is a mechanical relay having a contact; The electrical resistance between the power generation device and the storage battery, which is connected to the storage battery, is set to be greater than the electrical resistance between the power generation device and the storage battery via the second relay, and the control means includes the first relay and when a request to start the engine is issued while the second relay is open, the first relay is closed before the engine starts cranking, and the engine is cranked. The first relay and the second relay are controlled so that the second relay is closed (Claim 1).

In this configuration, when a request to start the engine is issued, the power generator and the storage battery are first connected with high electrical resistance between them only by the first relay. Therefore, it is possible to start up the electrical equipment provided in the power generation device while avoiding an excessively high inrush current from flowing through the electrical equipment. In addition, the first relay is closed before cranking starts, that is, before the engine starts rotating, so that the generator can generate power as cranking starts. The electrical equipment may be activated before the electrical equipment is powered by the power generator. Therefore, it is possible to appropriately determine the failure of the electrical device in a state in which the electrical device is supplied with stable power. In addition, since the first relay is made of a semiconductor and has no contacts, the first relay connects the power generation device and the storage battery before the start of cranking, and the connection produces a sound. can be prevented .

After the first relay is closed, the second relay is closed to connect the power generation device and the storage battery via a path having a relatively low electrical resistance. High voltage power can be applied to the machine. Moreover, the closing of the second relay , which is a mechanical relay having contacts, is performed during cranking. Therefore, when the second relay changes from the open state to the closed state, the sound generated from the second relay can be mixed with the engine rotation sound. can enhance sexuality. In other words, the second relay allows a large current to flow between the power generator and the storage battery, and the sound generated by the opening and closing of the contacts of the second relay can be blended into the engine rotation sound. It is possible to more reliably prevent the user from noticing the sound. Further, since high-voltage electric power can be applied to the generator immediately after the end of cranking, the generator can be operated immediately after the engine is started.

In the above configuration, preferably, the control means controls the second relay so that the second relay is closed after a preset delay period from the start of engine cranking (Claim 2). .

According to this configuration, the closing of the second relay can be more reliably performed during cranking, and the sound generated from the second relay can be more reliably blended into the rotation sound of the engine.

As described above, according to the vehicle power supply control device of the present invention, it is possible to improve comfort while appropriately connecting the storage battery and the electrical equipment such as the power generation device.

1 is a diagram schematically showing the configuration of a vehicle equipped with a power supply control device according to an embodiment of the invention; FIG. 1 is a block diagram showing a control system of a vehicle; FIG. 4 is a time chart showing changes over time in each parameter when the engine is started; 4 is a flow chart showing the flow of control when the engine is started.

(1) Overall Configuration of Vehicle FIG. 1 is a diagram schematically showing the configuration of a vehicle in which a power control device 100 is mounted.

Vehicle 1 is, for example, a four-wheel vehicle. The engine 2 is provided in an engine room of the vehicle 1 . The driving force of the engine 2 is transmitted from the crankshaft 2a to the wheels 1a via a transmission, a final reduction gear, a drive shaft and the like, thereby causing the vehicle 1 to run.

The vehicle 1 is equipped with an engine 2, a starter 3, a motor generator 4, a Li battery (lithium battery) 9, a switching device 60, a DC-DC converter 10, a lead battery 12, and various electric devices as a driving source of the vehicle. It is The motor generator 4 is a so-called ISG (Integrated Starter-Generator) having a function as an electric motor and a function as a generator, and is hereinafter referred to as ISG4. The Li battery 9 corresponds to a "storage battery" in the claims, and the ISG 4 corresponds to a "power generator" in the claims.

In the example of FIG. 1, the engine 2 is an in-line four-cylinder engine with four cylinders 2c arranged in a row. In this embodiment, the engine 2 is an engine driven by fuel containing gasoline. The engine 2 includes an injector 30 (see FIG. 2) that injects fuel into each cylinder 2c, and a spark plug 31 (see FIG. 2) that ignites the air-fuel mixture in each cylinder 2c. I have. One injector 30 and one spark plug 31 are provided for each cylinder 2c.

(high voltage system)
The Li battery 9 is electrically connected via a high voltage line L1 to an electric device driven at a high voltage (hereinafter referred to as high voltage device). The ISG 4 is included in high voltage equipment and connected to the Li battery 9 via the high voltage line L1. Specifically, the ISG 4 is connected to the Li battery 9 via a disconnecting device 60 . A seat heater 5 for heating the seat of the vehicle 1 and the like are also provided as high-voltage devices. In a vehicle equipped with a PTC heater for heating the interior of the vehicle 1 and a catalytic heater for heating a catalyst for purifying exhaust gas, these heaters are also connected to the Li battery 9 via the high voltage line L1.

The ISG 4 is connected to the crankshaft 2a of the engine 2 via a belt 4a. When operating as a generator, the ISG 4 generates power by rotating a rotor that rotates in a magnetic field in conjunction with the crankshaft 2a of the engine 2 via the belt 4a. The ISG 4 can adjust the generated voltage within a range up to several tens of volts depending on the increase or decrease in the supply current to the field coil that generates the magnetic field. The electric power generated by the ISG 4 is converted to direct current, output to the high voltage line L1, and stored in the Li battery 9 via the high voltage line L1. In this embodiment, the ISG 4 is controlled to operate as a generator during vehicle deceleration, converting the rotational energy of the engine 2 into electricity. That is, in this embodiment, the ISG 4 is configured to perform so-called deceleration regenerative power generation.

When operating as an electric motor, the ISG 4 is driven by power supply from the Li battery 9, transmits driving force to the crankshaft 2a of the engine 2 via the belt 4a, and imparts driving force to the engine 2. .

The vehicle 1 is configured so that the engine 2 can be automatically stopped, and when the engine 2 is restarted after the engine 2 is automatically stopped, the ISG 4 operates as an electric motor to forcibly rotationally drive the engine 2. - 特許庁Specifically, the vehicle 1 is provided with a start/stop switch SW1 (see FIG. 2) that can be operated by the passenger to start and stop the engine 2 . The engine 2 can be started and stopped by operating the start/stop switch SW1, but even if the start/stop switch SW1 is not operated, the vehicle speed is below a predetermined value and the brake pedal 1b is depressed. When the conditions such as the presence of the vehicle are met, the driving of the engine 2 is automatically stopped. After this automatic stop, when a condition such as depression of an accelerator pedal (not shown) is established, the engine 2 is automatically restarted regardless of whether the start/stop switch SW1 is operated or not. . The ISG 4 is driven as an electric motor to forcibly rotate the engine 2 when the engine 2 is automatically restarted.

Further, the ISG 4 operates as an electric motor when the engine load is low or the like to apply driving force to the engine 2 . That is, in this embodiment, the ISG 4 is also configured to perform so-called torque assist.

The ISG 4 is provided with an ISG controller 51 for controlling it. The ISG controller 51 has an inverter function, and converts the alternating current generated by the ISG 4 into a direct current when the ISG 4 functions as a generator, and the Li battery 9 when the ISG 4 functions as a motor. DC current from is converted into AC current and supplied to ISG4. Further, the ISG controller 51 increases or decreases the electric current supplied to the field coil as described above, thereby increasing or decreasing the amount of power generated by the ISG 4 and the driving force of the ISG 4 . The ISG controller 51 has a microcomputer including a microprocessor and the like, and the above current control and the like are performed by the microcomputer.

The Li battery 9 is a battery that contains lithium in its positive electrode and is charged and discharged by movement of lithium ions between the positive electrode and the negative electrode. The Li battery 9 can be charged and discharged at a faster rate than the lead battery 12 and is more resistant to deterioration due to charging and discharging than the lead battery 12 . In this embodiment, the power generated by the ISG 4 is stored in the Li battery 9, so that the deceleration energy of the engine 2 can be efficiently stored in the vehicle 1 as power. And the nominal voltage of the Li battery 9 is made higher than the negotiated voltage of the lead battery 12 so that more power generated by the ISG 4 can be stored. In this embodiment, the nominal voltage of the Li battery 9 is DC24V. Here, there is a capacitor as a device that has a high charge/discharge rate and can store a large amount of power, and the Li battery 9 can have a larger capacity than a capacitor of the same size. Therefore, in this embodiment, the miniaturization of the device for storing electric power is also realized.

The connecting/disconnecting device 60 is a device for connecting/disconnecting the Li battery 9 and a high-voltage device such as the ISG 4 . The disconnecting device 60 has two relays (a back charge relay 61 and a cutoff relay 62) and a relay controller 52 that controls these relays 61 and 62. As shown in FIG. The two relays 61, 62 are arranged in parallel with each other. Specifically, each high-voltage device has an electric cable extending from the branch portion L1_c, and the branch portion L1_c and the Li battery 9 are connected by two parallel paths. A back charge relay 61 is arranged on one path, and a cutoff relay 62 is arranged on the other path. An electrical resistance R1 is provided in the path in which the back charge relay 61 is provided, and the electrical resistance of the path passing through the back charge relay 61 is higher than the electrical resistance of the path passing through the cutoff relay 62. there is This electrical resistor R1 is arranged, for example, in a path between the back charge relay 61 and the branch portion L1_c. The back charge relay 61 corresponds to the "first relay" in the claims, and the cut-off relay 62 corresponds to the "second relay" in the claims.

The reason why the electrical resistance is arranged in the path passing through the back charge relay 61 is to avoid an excessive current from flowing through the high voltage equipment while supplying power to the high voltage equipment.

Specifically, if the Li battery 9 and the high-voltage device are connected without an electrical resistance, a large inrush current may flow from the Li battery 9 to the high-voltage device immediately after the connection, damaging the high-voltage device. On the other hand, if an electrical resistance is interposed between the Li battery 9 and the high voltage device, the rush current supplied to the high voltage device can be suppressed. From this, in this embodiment, as will be described later, first, in a state in which the cut-off relay 62 is open (in a state in which the connection between the Li battery 9 and the high-voltage device by the cut-off relay 62 is released), the back The charge relay 61 is closed (the back charge relay 61 connects the Li battery 9 and the high-voltage equipment), and current flows from the Li battery 9 to the high-voltage equipment via the electrical resistance R1. Then, after a predetermined voltage is applied to the high-voltage equipment and the potential difference between the Li battery 9 and the high-voltage equipment becomes small, the cut-off relay 62 is closed, and the cut-off relay 62 closes the Li battery 9 and the high voltage equipment. Make sure the device is connected. As described above, the electrical resistance of the path in which the cut-off relay 62 is arranged is made low. Therefore, when the cut-off relay 62 is closed, an appropriately high voltage is supplied from the Li battery 9 to the high-voltage equipment through the cut-off relay 62 . In this embodiment, the back charge relay 61 is opened when the cutoff relay 62 is closed.

The relay controller 52 is a device for switching the states of the two relays 61 and 62 between an open state and a closed state. The relay controller 52 receives commands from the PCM 90, which will be described later, to start/stop power supply to these relays 61 and 62, thereby switching the states of the relays 61 and 62. FIG. Thus, in this embodiment, the relay controller 52 and the PCM 90 function as control means for controlling the back charge relay 61 and cutoff relay 62, and correspond to "control means" in the claims.

In this embodiment, as the back charge relay 61, a non-contact relay made of a semiconductor and having no contacts is used. For example, one using a FET (Field-Effect Transistor) is used.

It is difficult to pass a large current through contactless relays made of semiconductors. On the other hand, as described above, a large current does not flow through the back charge relay 61 . Therefore, even if the back charge relay 61 is made of a semiconductor, it can be properly operated.

On the other hand, as the cut-off relay 62, a mechanical relay having contacts is used, and a large current can flow from the Li battery 9 to each high-voltage device via the cut-off relay 62. FIG.

Here, the back charge relay 61 having no contacts does not generate a switching sound when switched from the open state to the closed state. On the other hand, the cut-off relay 62 has contacts, and when switched from the open state to the closed state, the contact between the contacts generates a sound.

The Li battery 9 and the connecting/disconnecting device 60 configured as described above are arranged below a panel that constitutes the floor surface of the passenger compartment of the vehicle 1 . For example, the Li battery 9 and disconnecting device 60 are located below the front portion of the panel and below the driver's or passenger's seat.

(low voltage circuit)
The lead battery 12 is electrically connected to low-voltage electrical equipment (hereinafter referred to as low-voltage equipment) driven at a relatively low voltage through a low-voltage line L2, and these constitute a low-voltage circuit 15. The lead-acid battery 12 includes, for example, a series-connected 6-cell lead-acid battery with a nominal voltage of 12V DC.

The starter 3 is included in the low-voltage equipment, is connected to the lead battery 12 via the low-voltage line L2, and receives power from the lead battery 12 to drive. Starter 3 is a device for starting engine 2 . The starter 3 is a gear-driven device and has a pinion gear 3a connected to the ring gear 2b of the engine 2. As shown in FIG. The driving force of the starter 3 is transmitted to the crankshaft 2a of the engine 2 via the pinion gear 3a and the ring gear 2b. The starter 3 is also provided with a starter controller 54 for controlling the driving/stopping of the starter 3 .

As described above, in this embodiment, when the engine is restarted, the engine is rotationally driven by the ISG 4, and the starter 3 operates the start/stop switch SW1 to start the engine. When the start/stop switch SW1 is operated while the engine is stopped, the engine is rotationally driven.

In addition to the starter 3, the vehicle 1 is provided with low-voltage devices 13 such as an electric power steering mechanism (EAPS), an electric brake, an air conditioner, an audio device, various lighting devices, and the like.

The DC-DC converter 10 is a device for stepping down the voltage of power supplied from the high voltage line L1 to the low voltage line L2. The power output from the Li battery 9 and the power generated by the ISG 4 are stepped down by the DC-DC converter 10 and supplied to the low voltage device 13 . Moreover, the surplus part of the electric power generated by ISG4 is supplied to the lead battery 12, and the lead battery 12 is charged. The DC-DC converter 10 is provided with a connection/disconnection switch SW3 for connecting/disconnecting the high voltage line L1 and the low voltage line L2. When the connection/disconnection switch SW3 is closed, the high voltage line L1 and the low voltage line are connected. L2 is energized, and when the connecting/disconnecting switch SW3 is opened, the high voltage line L1 and the low voltage line L2 are cut off. The DC-DC converter 10 is provided with a converter controller 53 for controlling the connecting/disconnecting switch SW3 and a switch (not shown) for stepping down the input voltage.

(2) Control System FIG. 2 is a block diagram schematically showing the control system of the vehicle 1. As shown in FIG. The PCM 90 shown in FIG. 2 is a microprocessor for centrally controlling the engine, and is composed of a well-known CPU, ROM, RAM and the like.

Detection information from various sensors and operation signals of various switches are input to the PCM 90 . Specifically, the vehicle 1 includes an accelerator sensor SN1 that detects the opening of an accelerator pedal provided in the vehicle 1, a brake sensor SN2 that detects the depression amount of a brake pedal 1b provided in the vehicle 1, and a vehicle speed. A vehicle speed sensor SN3, a crank angle sensor SN4 for detecting the engine speed, and a start/stop switch SW1 for a passenger to start/stop the engine are provided. Signals are input to the PCM 90 from these sensors SN1 to SN4 and the start/stop switch SW1. In addition, the PCM 90 is connected to the injector 30, the spark plug 31, the ISG controller 51, the relay controller 52, the converter controller 53, the starter controller 54, the seat heater 5, etc., and the input information of each sensor and switch. Commands are issued to these units while executing various determinations, calculations, etc. based on the data. The PCM 90 and controllers 51 to 54 are connected by, for example, CAN (Controller Area Network). The PCM 90 is connected to the lead battery 12 and operates by receiving power from the lead battery 12 .

(3) Engine Startup Control Next, the control of the electrical system when the engine is started by operating the start/stop switch SW1 will be described with reference to the time chart of FIG. FIG. 3 shows, from top to bottom, the operating state of the start/stop switch SW1, the driving state of the starter 3, the operating state of the back charge relay 61, the operating state of the cutoff relay 62, the operating state of the disconnect switch SW3, and the ISG controller. 51 shows a graph of operating conditions and engine speed. In the graph of the start/stop switch SW1, "ON" indicates a state in which the start/stop switch SW1 is operated to start the engine, and "OFF" indicates a state in which the engine is stopped. In the graph of the starter 3, "ON" indicates the state in which the starter 3 is driven, and "OFF" indicates the state in which the drive is stopped. In the graphs of the relays 61 and 62 and the connecting/disconnecting switch SW3, "ON" indicates the state in which these relays and switches are closed, and "OFF" indicates the state in which they are open. Moreover, in the graph of the ISG controller 51, "ON" indicates a state in which the ISG controller 51 is activated, and "OFF" indicates a state in which the operation is stopped.

When the engine is stopped (after the engine is stopped by operating the start/stop switch SW1, not by automatic stop), the power supply to the PCM 90 and various electric devices is stopped, and back charging is performed. The relay 61, the cutoff relay 62 and the connecting/disconnecting switch SW3 are open.

In this state, when the start/stop switch SW1 is operated to issue an engine start request (at time t1 in FIG. 3), power is first supplied to the PCM 90 to start the PCM 90. FIG.

As the PCM 90 is activated, power supply from the lead battery 12 to low-voltage devices connected to the lead battery 12 is started, and the vehicle 1 is in a so-called IG ON state. However, at this time, the PCM 90 does not yet issue a command to the starter controller 54 to start driving the starter 3, and the starter 3 is kept stopped.

After starting the PCM 90, in the high voltage system, the cutoff relay 62 remains open and only the back charge relay 61 is closed (at time t2 in FIG. 3). That is, the PCM 90 first issues a command to the relay controller 52 to close the back charge relay 61 after starting. As a result, power is supplied from the Li battery 9 to the converter controller 53 and the ISG controller 51 via the back charge relay 61 . Upon receiving power, converter controller 53 and ISG controller 51 start up. At this time, since the cut-off relay 62 is opened, the voltage initially applied to each of the controllers 51 to 53 is appropriately suppressed as described above, and each of the controllers 51 and 53 is properly activated. In this embodiment, first, the converter controller 53 is activated, and accordingly, the connection/disconnection switch SW3 is closed to connect the high voltage circuit 14 and the low voltage circuit 15 (at time t3 in FIG. 3). ). After that, the ISG controller 51 is activated (at time t4 in FIG. 3). Even if the ISG controller 51 is activated, the driving of the ISG 4 is maintained in a stopped state.

In this embodiment, when the ISG controller 51 is activated, first, it is determined whether or not the ISG controller 51 is out of order. Along with this, after the ISG controller 51 is activated, the PCM 90 determines whether the ISG controller 51 is functioning normally based on an output signal such as a current sensor (not shown) provided in the ISG controller 51. make a judgment.

After this determination is completed, the PCM 90 issues a command to the starter controller 54 to start driving the starter 3 (at time t5 in FIG. 3). As a result, the starter 3 starts to be driven, and the engine starts cranking. That is, the engine is forcibly driven to rotate by the starter 3 . In addition, ISG4 also rotates with rotation of an engine.

When a preset delay time (delay period) Δt elapses after issuing a command to the starter controller 51 to start driving the starter 3, the PCM 90 issues a command to the ISG controller 51 and cuts off the relay 62 is closed (at time t6 in FIG. 3). This delay time is set to be shorter than the time from the issuance of the command to the end of cranking (until the drive of the starter 3 is stopped). closed inside. This delay time is set to about 100 ms, for example. By closing the cut-off relay 62, high voltage can be applied from the Li battery 9 to high-voltage devices including the ISG 4, so that the seat heater 5 can be driven and the ISG 4 can be driven as an electric motor. In this embodiment, when the cut-off relay 62 is closed, the back charge relay 61 is opened, and the Li battery 9 and the ISG 4 are connected only through the cut-off relay 62 . After that, the PCM 90 determines that the engine can rotate independently when the engine speed reaches a predetermined speed, and stops driving the starter 3 (at time t7 in FIG. 3).

In this way, in this embodiment, when the start/stop switch SW1 is operated and an engine start request is issued, the shut-off relay 62 is kept open until the engine starts cranking. The charge relay 61 is closed and the Li battery 9 and the high-voltage equipment such as the ISG 4 are connected only by the back charge relay 61 . Then, during cranking of the engine, the cutoff relay 62 is closed and the connection between the Li battery 9 and the high voltage equipment such as the ISG 4 is realized through the cutoff relay 62 .

When the engine is automatically stopped, the power to the PCM 90 is maintained, and the so-called IG ON state is maintained. Further, in this embodiment, when the engine is automatically stopped, the cutoff relay 62 is also kept closed, and the connection state between the Li battery 9 and the ISG 4 and the like via the cutoff relay 62 is also maintained. Therefore, the control of sequentially opening and closing the back charge relay 61 and the cutoff relay 62 as described above is performed only when the start/stop switch SW1 is operated to start the engine. In this embodiment, the time when the start/stop switch SW1 is operated to start the engine corresponds to "when there is a request to start the engine."

FIG. 4 is a flow chart showing the flow of control of the relays 61, 62, etc. when the engine is started, which is performed by the PCM 90, etc. As shown in FIG.

First, in step S1, the PCM 90 determines whether or not the IG is turned on. Specifically, it is determined whether or not the start/stop switch SW1 has been operated to start the engine. If this determination is NO, the process is terminated without performing subsequent steps. On the other hand, if the determination is YES and the IG is turned on, that is, if the start/stop switch SW1 is operated to start the engine, the process proceeds to step S2. In step S2, the PCM 90 (more specifically, the relay controller 52 that has received a command from the PCM 90) closes the back charge relay 61 to connect the Li battery 9 and the ISG 4 through the back charge relay 61. do. Along with this, in step S3, the ISG controller 51 and the converter controller 53 are activated.

After step S3, the process proceeds to step S4. In step S4, the converter controller 53 closes the connecting/disconnecting switch SW3 to connect the low voltage circuit 15 and the high voltage circuit 14 to each other. The PCM 90 also diagnoses the failure of the ISG controller 51 .

After step S4, the process proceeds to step S5. In step S5, the PCM 90 determines whether or not the drive start condition for the starter 3 is satisfied. In this embodiment, when the driving start condition is not met, such as when the brake pedal 1b is depressed, the engine is prohibited from starting even if the start/stop switch SW1 is operated. , the PCM 90 determines whether or not the drive start condition is established.

If the determination in step S5 is NO and the drive start condition for the starter 3 is not satisfied, the process proceeds to step S6. In step S6, the PCM 90 determines whether or not the IG has been turned off, that is, whether or not the start/stop switch SW1 has been operated to stop the engine. If the determination is YES and the start/stop switch SW1 is operated to stop the engine and the IG is turned off, the process proceeds to step S7, and the PCM 90 (more specifically, the relay controller 52) switches back The charge relay 61 is opened to disconnect the Li battery 9 from the ISG 4 and the like. On the other hand, if the determination in step S6 is NO and the start/stop switch SW1 is not operated to stop the engine and the IG is not turned off, the process returns to step S5. In other words, after step S4, the PCM 90 waits for the starter 3 to start driving unless the start/stop switch SW1 is operated to stop the engine and the IG is turned off.

If the determination in step S5 is YES, and the drive start condition for the starter 3 is satisfied, the process proceeds to step S8. In step S8, the PCM 90 commands the starter 3 to start driving (commands the starter controller 54 to drive the starter 3). Along with this, the starter 3 starts driving. After step S8, the process proceeds to step S9. In step S9, the PCM 90 determines whether or not the delay time Δt has elapsed since the starter 3 was instructed to start driving. If this determination is NO and the delay time has not yet passed, step S9 is executed again. That is, the PCM 90 waits for the delay time Δt to elapse before proceeding to the next step S10.

When the determination in step S9 becomes YES and the delay time Δt elapses, the process proceeds to step S10, and the PCM 90 (more specifically, the relay controller 52) closes the cutoff relay 62, and the Li The battery 9 and the ISG 4 etc. are put into a connected state. After step S10, the process proceeds to step S11. In step S11, the PCM 90 (more specifically, the relay controller 52) opens the back charge relay 61 to disconnect the Li battery 9 and the ISG 4 and the like via the back charge relay 61. FIG.

After step S11, the process proceeds to step S12. In step S12, the PCM 90 determines whether or not the IG has been turned off, that is, whether or not the start/stop switch SW1 has been operated to stop the engine. If the determination is YES and the IG is turned off, the process proceeds to step S13. In step S13, the PCM 90 (more specifically, the relay controller 52) opens the cutoff relay 62 to disconnect the Li battery 9 and the ISG 4, etc., and opens the connection/disconnection switch SW3 to end the process. (return to step S1). On the other hand, if the determination in step S12 is NO and the IG is not turned off, step S12 is executed again. That is, when the IG is not turned off, that is, unless the start/stop switch SW1 is operated to stop the engine, the PCM 90 maintains the cut-off relay 62 and the connection/disconnection switch SW3 in a closed state to stop the engine. When the operation is performed, the process proceeds to step S13, the cut-off relay 62 and the connecting/disconnecting switch SW3 are opened, and the process ends.

(4) Operation, etc. As described above, in this embodiment, when an operation for starting the engine is performed on the start/stop switch SW1 and an engine start request is issued, first, the back charge relay 61 is closed, and the Li battery 9 and the high voltage device such as the ISG 4 are connected via the back charge relay 61 via the electrical resistance R1. Therefore, the ISG controller 51 provided in the ISG 4, the converter controller 53 provided in the DC-DC converter 10, etc. can be prevented from flowing an excessively high inrush current, and these can be started appropriately.

In addition, since the back charge relay 61 is closed before cranking starts, failure determination of the ISG controller 51 can be performed appropriately. Specifically, when cranking starts, the ISG 4 is rotationally driven by the engine, thereby generating electric power in the ISG 4 . This electric power fluctuates because it depends on the rotational state of the engine. Therefore, if the ISG controller 51 is started during cranking, a stable current does not flow through the ISG controller 51, and there is a risk that the ISG controller 51 will not be properly started. Further, if the current flowing through the ISG controller 51 fluctuates, it may not be possible to determine whether or not the fluctuation is due to the failure of the ISG controller 51, and the failure may not be properly determined. On the other hand, in this embodiment, before cranking, that is, before the rotation of the ISG 4, the ISG controller 51 is appropriately activated by applying a constant voltage from the Li battery 9 to the ISG controller 51. can be performed, and failure determination can be performed with high accuracy.

Then, after the ISG controller 51 and the like are activated by closing the back charge relay 61, the cutoff relay 62 is closed and the high voltage equipment such as the Li battery 9 and the ISG 4 are connected via a path with low electrical resistance. By doing so, while appropriately activating the ISG controller 51 and the like as described above, it is possible to apply a high voltage to the high-voltage devices such as the ISG 4 and drive the ISG 4 and the like appropriately.

Furthermore, in this embodiment, closing of the cut-off relay 62 is performed during cranking. Therefore, the sound generated from the cut-off relay 62 when the cut-off relay 62 is changed from the open state to the closed state can be mixed with the rotation sound of the engine, and the occupant can be prevented from feeling discomfort due to the sound. This increases the comfort of vehicle 1 . Further, it becomes possible to apply high voltage power to high voltage devices such as the ISG 4 immediately after the end of cranking. Therefore, it is possible to operate them immediately after the engine is started.

In particular, in this embodiment, after the delay time Δt has passed since the starter 3 (starter controller 54) was instructed to start driving from the PCM 90, that is, after the starter 3 starts driving, the delay time Δ After t has elapsed, the cut-off relay 62 is closed. Therefore, the cut-off relay 62 can be reliably closed after cranking starts, and the sound generated from the cut-off relay 62 can be reliably blended into the engine rotation sound.

Furthermore, in this embodiment, a non-contact relay made of a semiconductor that does not make a sound when opened and closed is used as the back charge relay 61 that is closed before cranking. Therefore, when the back charge relay 61 is closed, it is possible to avoid making a sound that makes the passenger feel uncomfortable. As the breaker relay 62, a mechanical relay having a contact makes a sound when opening and closing, but a relay capable of flowing a large current is used. A large current can flow from 9 .

A mechanical relay may be used as the back charge relay 61 as well. Even in this case, since a small-sized relay can be used as the back charge relay 61 because the current flowing through the back charge relay 61 is small, the sound generated from the back charge relay 61 can be suppressed. .

(5) Modification In the above-described embodiment, the case of using the Li battery 9 as a storage battery for storing the power generated by the ISG 4 has been described, but this storage battery is not limited to the Li battery 9 .

Further, in the above embodiment, the ISG 4 functioning as an electric motor is used as a power generator that is rotationally driven by the engine to generate power, but this power generator may have only the power generation function.

2 engine 3 starter 4 ISG (power generator)
9 Li battery (storage battery)
52 relay controller (control means)
61 Back charge relay (1st relay)
62 cut-off relay (second relay)
90 PCM (control means)

Claims (2)

a storage battery;
a power generating device that includes an electric device that is activated by power supplied from the storage battery, that is driven by an engine to generate power and that can supply the generated power to the storage battery ;
a first relay and a second relay disposed in parallel between the power generation device and the storage battery to connect and disconnect the power generation device and the storage battery, respectively;
A control means for controlling the first relay and the second relay,
The first relay is a relay made of a semiconductor and having no contacts,
The second relay is a mechanical relay having contacts,
The electrical resistance between the power generator and the storage battery via the first relay is greater than the electrical resistance between the power generator and the storage battery via the second relay,
The control means closes the first relay until the engine starts cranking when a request to start the engine is issued with the first relay and the second relay open. and controlling the first relay and the second relay so that the second relay is closed during engine cranking. In the vehicle power supply control device according to claim 1,
A power supply control device for a vehicle, wherein the control means controls the second relay so that the second relay is closed after a preset delay period from the start of engine cranking.

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