JP2011094517A - Voltage control device and method for nullifying idling stop function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology to prevent malfunction of an electric load caused at starting of an engine by an idling stop function. <P>SOLUTION: In this voltage control device, whether a boosting circuit is normal is confirmed at a period from an engine starting instruction from a user to the first stop of the engine by the idling stop function. When the boosting circuit is not normal, the idling stop function is nullified (Step S20). Therefore, the malfunction of the electric load caused during starting of the engine by the idling stop function is surely prevented. Since the operation check of the boosting circuit is performed during driving of a starter motor with a battery voltage remarkably reduced (Step S12), voltage is comparatively greatly raised when performing the operation check of the boosting circuit without applying a voltage higher than a rated voltage to the electric load, improving the determination accuracy of the operation check. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique for controlling a voltage supplied to an electric load of a vehicle in a vehicle having an idling stop function.

  In recent years, an idling stop function for automatically stopping / starting a vehicle engine while a vehicle is stopped for a relatively short time such as waiting for a signal has been put into practical use for the purpose of saving fuel and reducing exhaust gas. In vehicles equipped with an idling stop function, the engine is automatically stopped when a stop condition such as the brake is depressed from the running state and the engine is stopped, and the start condition is such that the brake is released while the engine is stopped. When is established, the engine is automatically started.

  Generally, in a vehicle, electric power for operating a starter motor for starting an engine and various electric loads (electronic control device, navigation device, etc.) provided in the vehicle is supplied from the same battery. Since the power required by the starter motor for starting the engine is very large, the battery voltage is greatly reduced when the engine is started by the idling stop function. As a result, the voltage supplied to various electric loads other than the starter motor included in the vehicle also greatly decreases, and the electric load may become inoperable and reset. If the electric load is reset when the engine is started by the idling stop function in this way, various problems may occur.

  For example, when the vehicle meter is reset, there is a possibility that the information that the user needs to travel cannot be obtained while the vehicle is stopped. Further, when the navigation device is reset, it may take time to restart and the necessary route guidance cannot be performed, or the music being played may be interrupted, which may cause discomfort to the user. In addition, since an electronic control device that handles a brake such as an ABS control device checks the brake valve every time it is activated, there is a possibility that the life of the brake valve may be shortened if the reset of the electronic control device is repeated.

  In order to avoid such a problem of the electric load, a technique has been proposed that includes a booster circuit that boosts the voltage supplied from the vehicle battery and supplies the electric load to the electric load when the engine is started by the idle stop function (for example, (See Patent Document 1). If this technique is adopted, resetting of the electric load at the time of engine start by the idle stop function can be avoided, and the trouble of the electric load can be prevented.

JP 2002-38984 A JP 2007-56728 A

  By the way, when the above-described boosting circuit fails, the boosting operation cannot be normally performed, and thus a problem of an electric load occurs when the engine is started by the idle stop function. In order to cope with this, a technique has been proposed in which the booster circuit performs a boost operation after the engine is stopped by the idle stop function to check whether the booster circuit is normal (for example, refer to Patent Document 2). .)

  However, in the technique disclosed in Patent Document 2, since the operation of the booster circuit is checked after the engine is stopped by the idle stop function, the engine must be restarted even when the booster circuit is determined to be abnormal. . For this reason, a malfunction of the electric load occurs because the booster circuit does not operate normally when the engine is restarted, and the malfunction of the electric load at the time of starting the engine cannot be completely avoided. Further, in the technique of Patent Document 2, when the booster circuit is determined to be abnormal, it is restarted by the user. , May cause confusion for the user.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of preventing a problem of an electric load that occurs during engine startup by an idling stop function.

  In order to solve the above problems, the invention of claim 1 is mounted on a vehicle having an idling stop function for automatically stopping / starting an engine when a predetermined condition is satisfied, and a voltage supplied to an electric load of the vehicle is set. A voltage control device for controlling, wherein the engine supplied by the idling stop function boosts a voltage supplied from a battery of the vehicle and supplies the voltage to the electric load; Confirming means for confirming whether or not the booster circuit is normal by causing the booster circuit to perform a boosting operation during a period from a start instruction until the engine is stopped for the first time by the idling stop function. Disabling means for disabling the idling stop function when the circuit is not normal.

  According to a second aspect of the present invention, there is provided the voltage control device according to the first aspect, wherein the confirmation unit is configured to operate the booster circuit during driving of a starter motor that starts the engine according to a start instruction from the user. The operation check is performed.

  According to a third aspect of the present invention, in the voltage control device according to the second aspect, during the driving of the starter motor, an initial state in which the load on the battery is relatively large from an initial state in which the load on the battery is relatively small. Transition determining means for determining that the transition to (1) is further performed, and the confirmation means confirms the operation of the booster circuit after transitioning to the latter state during driving of the starter motor.

  According to a fourth aspect of the present invention, in the voltage control apparatus according to the first aspect, the confirmation means confirms the operation of the booster circuit after the engine has been completely exploded.

  According to a fifth aspect of the present invention, in the voltage control apparatus according to the fourth aspect, the operation of the booster circuit is performed in a state where the confirmation unit does not generate power from a generator that stores the generated power in the battery. Confirm.

  According to a sixth aspect of the present invention, in the voltage control apparatus according to the fourth aspect, the confirmation means performs the operation confirmation of the booster circuit during the power generation of the generator that stores the generated power in the battery. In addition, the generator is instructed to set a command voltage that is a target of power generation to be lower than before the operation check.

  According to a seventh aspect of the present invention, in the voltage control apparatus according to the sixth aspect, the confirmation means sets the boost target of the booster circuit in the operation confirmation as an instruction voltage before performing the operation confirmation.

  The voltage control device according to claim 8 is the voltage control device according to claim 4, wherein the confirming unit is configured to perform the operation of the booster circuit when the generator that stores the generated power in the battery is generating power. When checking, when the generator is instructed to lower the target voltage for power generation of the generator lower than before performing the operation check, and the generator is not generating power, The operation of the booster circuit is checked while maintaining the power generation state.

  The invention according to claim 9 is the voltage control device according to any one of claims 4 to 8, wherein the confirmation means further confirms the operation each time the engine is stopped and started by the idling stop function. I do.

  The invention of claim 10 is a method for invalidating the idling stop function in a vehicle having an idling stop function for automatically stopping / starting the engine when a predetermined condition is satisfied, wherein the idling stop function The booster circuit that boosts the voltage supplied from the battery of the vehicle during startup of the engine and supplies it to the electric load of the vehicle performs a boost operation to check whether the booster circuit is normal And a disabling step of disabling the idling stop function when the booster circuit is not normal, and the checking step is performed by the idling stop function from a start instruction of the engine from a user. This is done before the engine is shut down for the first time.

  According to the first to tenth aspects of the present invention, it is confirmed whether or not the booster circuit is normal before the engine is stopped for the first time by the idling stop function from the engine start instruction from the user. Disable the idling stop function. For this reason, the malfunction of the electric load which arises during the engine start by an idling stop function can be prevented.

  In particular, according to the second aspect of the present invention, since the operation of the booster circuit is checked during driving of the starter motor in which the voltage of the battery is greatly reduced, the voltage can be boosted relatively large when checking the operation of the booster circuit. The determination accuracy can be improved.

  In particular, according to the invention of claim 3, since the operation of the booster circuit is checked after shifting to a later state where the load of the battery is relatively small, the booster circuit is normal without affecting the starting performance of the engine. You can check whether or not.

  In particular, according to the invention of claim 4, it is possible to confirm whether or not the booster circuit is normal without affecting the starting performance of the engine.

  In particular, according to the invention of claim 5, since the operation of the booster circuit is checked while the generator is not generating power, the voltage can be boosted relatively large when checking the normality of the booster circuit. Can be improved.

  In particular, according to the invention of claim 6, since the instruction voltage is instructed lower than the reference voltage when the operation of the booster circuit is confirmed, the voltage can be boosted relatively large when confirming the normality of the booster circuit. The determination accuracy can be improved.

  In particular, according to the invention of claim 7, since there is no fluctuation of the output voltage when the operation check is performed, the operation check can be performed without affecting the electric load.

  According to the invention of claim 8 in particular, since the operation check of the booster circuit is performed by an appropriate method according to the power generation status of the generator, the operation check of the booster circuit can be executed regardless of the power generation status of the generator.

  In particular, according to the invention of claim 9, since the operation is confirmed every time the engine is stopped and started by the idling stop function, a sudden abnormality of the booster circuit can be confirmed.

FIG. 1 is a diagram illustrating an outline of an electric system provided in a vehicle. FIG. 2 is a diagram illustrating a configuration of the voltage control apparatus. FIG. 3 is a diagram illustrating a relationship between an input voltage and an output voltage during operation confirmation in the first embodiment. FIG. 4 is a diagram showing a flow of processing relating to operation confirmation in the first embodiment. FIG. 5 is a diagram illustrating a relationship between an input voltage and an output voltage during operation confirmation in the second embodiment. FIG. 6 is a diagram showing a flow of processing relating to operation confirmation in the second embodiment. FIG. 7 is a diagram showing a flow of processing relating to operation confirmation in the third embodiment. FIG. 8 is a diagram illustrating the relationship between the input voltage and the output voltage during operation confirmation in the third embodiment. FIG. 9 is a diagram illustrating the relationship between the input voltage and the output voltage during operation confirmation in the third embodiment. FIG. 10 is a diagram showing a detailed flow of the boost determination processing.

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

<1. First Embodiment>
<1-1. Configuration>
FIG. 1 is a diagram showing an outline of an electric system 100 provided in a vehicle such as an automobile. As shown in the figure, the electric system 100 includes the idling stop device 2, the battery 3, the starter motor unit 41, the alternator unit 42, the engine control device 43, the first electric load, together with the voltage control device 1 according to the present embodiment. 44 and a second electric load 45.

  The battery 3 is composed of, for example, a lead storage battery, and supplies power to various electric loads mounted on the vehicle. As shown in FIG. 1, a starter motor unit 41, an alternator unit 42, and the voltage control device 1 are connected to the power supply line 9 from the battery 3. The first electric load 44 is supplied with power from the battery 3 via the voltage control device 1. On the other hand, the second electrical load 45 is connected to the power supply line 9, and power is directly supplied from the battery 3.

  The starter motor unit 41 includes a starter motor for starting the engine, and drives the starter motor with electric power supplied from the battery 3. The starter motor unit 41 drives the starter motor to start the engine when the start switch 91 operated by the user is turned on and when a signal instructing start of the engine is received from an external device. It can be said that the ON operation of the start switch 91 by the user is an engine start instruction from the user. The user turns on the start switch 91 by rotating the key or pressing the start button.

  The alternator unit 42 includes an alternator that is a generator. The alternator converts mechanical kinetic energy transmitted from the engine into AC power, and further rectifies it into DC power using a rectifier including a diode. The generated power is stored in the battery 3 via the power line 9. The alternator unit 42 monitors the voltage of the battery 3. When the voltage of the battery 3 is lower than a predetermined reference voltage, the alternator unit 42 generates power with the alternator and charges the battery 3. Further, the alternator unit 42 uses the kinetic energy of the vehicle to generate power with the alternator and charge the battery 3 even during deceleration of the vehicle (energy regeneration). When the alternator generates power, an instruction voltage that is a target of power generation is set, and the alternator generates power so that the voltage of the power supply line 9 becomes the instruction voltage.

  The engine control device 43 controls the operation of the engine by controlling the operation of the engine throttle, injector, and spark plug. Moreover, the engine control apparatus 43 stops an engine, when the signal which instruct | indicates the engine stop from an external device is received.

  The idling stop device 2 has an idling stop function for automatically stopping / starting the engine of the vehicle while the vehicle is stopped for a relatively short time such as waiting for a signal from the vehicle. The idling stop device 2 includes a microcomputer, and an idling stop function is realized by an arithmetic operation of the microcomputer.

  A signal indicating the traveling state of the vehicle is input to the idling stop device 2 from various in-vehicle sensors 46 provided in the vehicle. Specifically, vehicle speed is input from the vehicle speed sensor, shift lever position from the shift sensor, accelerator operation content from the accelerator sensor, and brake operation content from the brake sensor.

  When a predetermined stop condition is established based on these signals indicating the running state, the engine is stopped by the idling stop function. For example, the stop condition is satisfied when all of the conditions “vehicle speed is 0”, “shift lever is“ D ””, “no accelerator operation”, and “brake operation” are satisfied. To be judged. When stopping the engine, the microcomputer of the idling stop device 2 transmits a signal instructing the engine control device 43 to stop the engine. The engine control device 43 stops the engine in response to this signal.

  Further, when a predetermined start condition is established based on a signal indicating the running state while the engine is stopped by the idling stop function, the engine is automatically started by the idling stop function. For example, the start condition is determined to be satisfied when all of the conditions “shift lever is“ D ””, “accelerator operated”, and “brake not operated” are all satisfied. When starting the engine, the microcomputer of the idling stop device 2 transmits a signal instructing the starter motor unit 41 to start the engine. In response to this signal, the starter motor unit 41 drives the starter motor to start the engine.

  The voltage control device 1 boosts the voltage of the battery 3 supplied via the power supply line 9 and supplies the boosted voltage to the first electric load 44. When the engine is started by the idling stop function of the idling stop device 2, the voltage control device 1 performs a boost operation to generate a voltage for driving the first electric load 44 and supplies the voltage to the first electric load 44. .

  Since the electric power required by the starter motor for starting the engine is very large, the voltage of the battery 3 greatly decreases when the engine is started by the idling stop function. In this case, the voltage boosted by the voltage control device 1 is supplied to the first electric load 44. Therefore, the first electrical load 44 operates without being affected by the voltage drop of the battery 3 even when the engine is started by the idling stop function. On the other hand, since the second electric load 45 is directly supplied with power from the battery 3 without going through the voltage control device 1, it is affected by the voltage drop of the battery 3 when the engine is started by the idling stop function. .

  For this reason, as the first electric load 44, an electric load that causes a malfunction when the voltage of the battery 3 drops and a reset occurs is selected. On the other hand, as the second electrical load 45, an electrical load is selected that does not cause a major problem even when the voltage of the battery 3 drops and a reset occurs.

  The first electrical load 44 is, for example, a navigation device, an audio device, a meter, an EPS (Electric Power Steering) control device, an ABS (Anti-lock Braking System) control device, or a VSC (Vehicle Stability Control) control device. . As for the navigation device and the audio device, when the reset occurs, the music being played may be interrupted, which may cause discomfort to the user. Furthermore, in the navigation device, when reset occurs, it takes time to restart, and there is a possibility that necessary route guidance cannot be performed. In addition, when the meter is reset, there is a possibility that information necessary for the user to travel while the vehicle is stopped may not be obtained. In the EPS control device, when the reset occurs, the operability of the steering of the vehicle may be deteriorated. Further, since the ABS control device and the VSC control device check the brake valve at the time of activation, there is a possibility that the life of the brake valve may be shortened if the reset is repeated.

  On the other hand, the second electrical load 45 is, for example, a power window device or a door lock device. These are rarely handled during engine start-up by the idling stop function, and no major malfunction occurs even if reset is applied.

  FIG. 2 is a diagram illustrating the configuration of the voltage control device 1 together with the configuration around the voltage control device 1. As shown in FIG. 2, the voltage control device 1 includes a booster circuit 11, an input voltage detection circuit 12, a switch drive circuit 13, an output voltage detection circuit 14, and a control unit 10.

  The booster circuit 11 is connected to an input line 61 connected to the battery 3 via the power supply line 9 and an output line 62 connected to the first electric load 44. The booster circuit 11 boosts the voltage of the battery 3 supplied via the input line 61 and supplies the voltage generated thereby to the first electric load 44 via the output line 62.

  The booster circuit 11 includes a coil 51, a MOS transistor 52, a diode 53, and a capacitor 54. The coil 51 has one end connected to the input line 61 and the other end connected to the anode of the diode 53. The cathode of the diode 53 is connected to the output line 62. The drain of the MOS transistor 52 is connected between the coil 51 and the diode 53, and the source of the MOS transistor 52 is grounded. Further, the capacitor 54 has one end connected to the cathode of the diode 53 and the other end grounded.

  The gate of the MOS transistor 52 is connected to the switch drive circuit 13. The switch driving circuit 13 turns on / off the MOS transistor 52 as a switching element to boost the voltage of the input line 61 and output the boosted voltage from the output line 62.

  Specifically, when the MOS transistor 52 is turned on, a current flows from the input line 61 toward the MOS transistor 52. Therefore, a current flows through the coil 51, and energy is accumulated in the coil 51 in the form of magnetism. In this state, when the MOS transistor 52 is turned off, the energy accumulated in the coil 51 flows to the capacitor 54 as electric energy, and the capacitor 54 is charged. Therefore, the voltage is boosted by repeatedly turning on / off the MOS transistor 52. The degree of boosting by the booster circuit 11 can be adjusted by the frequency and duty ratio at which the MOS transistor 52 is turned on / off.

  The input voltage detection circuit 12 detects the voltage of the input line 61 (hereinafter referred to as “input voltage”), that is, the voltage of the battery 3. The output voltage detection circuit 12 detects the voltage of the output line 62 (hereinafter referred to as “output voltage”), that is, the voltage supplied to the first electric load 44. The voltages detected by the input voltage detection circuit 12 and the output voltage detection circuit 14 are respectively input to the control unit 10.

  The control unit 10 is configured as a microcomputer including a CPU, RAM, ROM, and SRAM (Standby RAM). Various functions of the control unit 10 are realized by the CPU performing arithmetic processing according to a program recorded in advance in the ROM. The SRAM is configured to hold stored information unless power is directly supplied from the battery 3 and the battery 3 is removed from the vehicle.

  The control unit 10 is connected to the starter motor unit 41, the alternator unit 42, the engine control unit 43, the idling stop device 2 and the like via an in-vehicle communication line, and can transmit and receive various signals to and from these processing units. Yes.

  The control unit 10 controls the boosting operation of the booster circuit 11 based on the input voltage and the output voltage input from the input voltage detection circuit 12 and the output voltage detection circuit 14 so that the output voltage becomes a target value for boosting. To do. Specifically, the control unit 10 determines the frequency and duty ratio for turning on / off the MOS transistor 52, and outputs a signal to the switch drive circuit 13 so as to drive the MOS transistor 52 with the determined frequency and duty ratio. .

  When the engine is started by the idling stop function, the control unit 10 controls the boosting operation of the booster circuit 11 so that the output voltage during engine startup matches the input voltage immediately before engine startup. The control unit 10 grasps the start timing of the engine based on the signal input from the idling stop device 2. By such control, even when the engine is started by the idling stop function, a stable voltage is supplied to the first electric load 44, and the malfunction of the first electric load 44 is prevented.

  In addition, the control unit 10 causes the booster circuit 11 to perform a boosting operation at a predetermined timing and confirms whether or not the booster circuit 11 is normal. In this operation check, when it is determined that the boosting operation of the booster circuit 11 is not normal, a signal is transmitted to the idling stop device 2 and thereafter the idling stop function is invalidated.

  When the boosting operation of the booster circuit 11 is not normal, a voltage that is correctly boosted is not supplied to the first electric load 44 when the engine is started by the idling stop function. . For this reason, when the boosting operation of the booster circuit 11 is not normal, the control unit 10 invalidates the idling stop function and avoids the malfunction of the first electric load 44.

  In addition, the control unit 10 performs the operation check of the booster circuit 11 at least once from the start instruction of the engine from the user until the engine is stopped for the first time by the idling stop function. In this way, the operation check of the booster circuit 11 is executed before the engine is stopped, and if there is an abnormality, the idling stop function is disabled, so that the engine is operated with the idling stop function even though the booster circuit 11 is abnormal. The situation of stopping can be avoided. Thereby, since the engine start itself by the idling stop function does not occur, it is possible to reliably prevent the first electric load 44 from malfunctioning when the engine is started.

<1-2. Operation check operation>
In the operation check, the booster circuit 11 is actually boosted to determine normality / abnormality. Since the voltage of the battery 3 fluctuates due to the influence of various loads, in order to ensure the determination accuracy in the operation check, it is necessary to boost the voltage relatively large enough not to be affected by the fluctuation of the voltage of the battery 3. is there. On the other hand, each voltage of the first electrical load 44 has a rating, and if the boosting operation of the booster circuit 11 is performed ignoring this rating, the output voltage rises greatly and the first electrical load 44 has a voltage higher than the rating. And the first electrical load 44 may fail. For this reason, even if the boosting operation of the booster circuit 11 is performed, it is necessary to check the operation so that the output voltage does not exceed the rating of the first electric load 44.

  The control unit 10 according to the present embodiment confirms the operation of the booster circuit 11 when the engine is started (so-called initial start) in response to a start instruction from the user. That is, when the start switch 91 is turned on by the user and the starter motor unit 41 is driven by the starter motor unit 41 in response thereto, the operation of the booster circuit 11 is confirmed in the control unit 10 of the voltage control device 1. Since the voltage of the battery 3 is greatly reduced while the starter motor is driven, the output voltage may not exceed the rating of the first electric load 44 even if the booster circuit 11 boosts the voltage relatively large and confirms the operation. Absent.

  FIG. 3 is a diagram showing the relationship between the input voltage and the output voltage during operation confirmation when the booster circuit 11 is normal. In the drawing, a voltage E1 indicated by a solid line is an input voltage before boosting (that is, a voltage of the battery 3), and a voltage E2 indicated by a one-dot chain line is an output voltage after being boosted (that is, a voltage supplied to the first electric load 44). Is shown.

  Further, the hatched portion in the figure indicates the difference between the input voltage E1 and the output voltage E2 due to the boosting operation of the booster circuit 11. If an abnormality has occurred in the booster circuit 11, a normal boost operation is not performed, and the difference between the input voltage E1 and the output voltage E2 is smaller than that shown in the figure.

  In the following description, the voltage of the battery 3 in a state where there is no load and is not charged is assumed to be the initial voltage Vbatt. The initial voltage Vbatt is, for example, 12.5V. In addition, an instruction voltage that is the target of power generation by the alternator after the engine is started is a voltage Valt. The voltage Valt is 14.5V, for example.

  When there is a start instruction from the user, the starter motor is driven to start the engine (time point T1). Immediately after the start of engine startup, a relatively large torque is required to rotate the engine, and therefore a relatively large current flows through the starter motor. Therefore, the load of the battery 3 becomes relatively large, and the input voltage E1 greatly decreases from the initial voltage Vbatt. In this description, a state in which the load of the battery 3 is relatively large while the starter motor is driven is referred to as an “initial state”.

  Thereafter, as the engine speed increases, the torque required for engine rotation decreases, so the current flowing through the starter motor also decreases. Thereby, the load of the battery 3 becomes relatively small, and the input voltage E1 rises (time point T2). In this description, such a state in which the load of the battery 3 is relatively small during driving of the starter motor is referred to as a “late state”.

  Thereafter, when the engine completes explosion (completely starts), the starter motor is stopped. At the same time, since the power generation of the alternator is started, the input voltage E1 rises to a voltage Valt higher than the initial voltage Vbatt (time point T3).

  In the present embodiment, the boosting operation is performed at the time of starting the engine, and if the output voltage E2 is boosted to the target value, it is determined that the booster circuit 11 is normal. Specifically, if the output voltage E2 rises above the initial voltage Vbatt, it is determined that the booster circuit 11 is normal. Conversely, when the output voltage E2 is less than the initial voltage Vbatt, it is determined that the booster circuit 11 is abnormal. In the present embodiment, the operation check is performed by the booster circuit 11 at the start of the engine when the input voltage E1 greatly decreases. Therefore, the operation check can be performed by greatly boosting the voltage, and the determination accuracy of the operation check can be improved.

  FIG. 4 is a diagram showing a flow of processing related to operation confirmation by the control unit 10 of the voltage control apparatus 1. First, it is determined whether or not there is a start instruction from the user (step S11). Specifically, it is determined whether or not the start switch 91 is turned on. If there is a start instruction from the user, it is subsequently determined whether or not the starter motor has been driven by a signal from the starter motor unit 41 (step S12).

  When the drive of the starter motor is confirmed, a signal is transmitted from the control unit 10 to the switch drive circuit 13, and the boosting operation by the booster circuit 11 is started. The target value for boosting by the booster circuit 11 at this time is the initial voltage Vbatt, that is, the input voltage E1 before driving the starter motor (step S13).

  Thereafter, as shown in FIG. 3, the input voltage E1 is reduced by driving the starter motor. However, if the booster circuit 11 is normal, the output voltage E2 is maintained at or above the initial voltage Vbatt that is the target value for boosting. On the other hand, if the booster circuit 11 is abnormal, the output voltage E2 will decrease.

  Therefore, the output voltage E2 is confirmed, and if the output voltage E2 is equal to or higher than the initial voltage Vbatt that is the target value (Yes in step S14), it is determined that the booster circuit 11 is normal (step S15). Then, when the engine is completely detonated (Yes in step S16), a signal is transmitted from the control unit 10 to the switch drive circuit 13, the boosting instruction to the booster circuit 11 is stopped (step S17), and the process is completed. To do. In this case, the idling stop function is effective.

  Determination of the complete explosion of the engine can be made by increasing the input voltage E1, stopping the starter motor, or when the engine speed reaches a predetermined speed (for example, 500 rpm). Stopping of the starter motor can be determined by a signal from the starter motor unit 41. Further, the engine speed can be determined by a signal from the engine control device 43.

  On the other hand, if output voltage E2 is less than target voltage initial voltage Vbatt (No in step S14), boost circuit 11 is determined to be abnormal (step S18). In this case, first, the boosting instruction to the booster circuit 11 is stopped (step S19). And the signal which instruct | indicates invalidation is transmitted from the control part 10 to the idling stop apparatus 2, and a process is complete | finished. Thereby, thereafter, the idling stop function of the idling stop device 2 is invalidated (step S20). For this reason, the engine is not automatically stopped by the idling stop function even when a predetermined stop condition is satisfied based on the signal indicating the running state. Thereby, since the engine restart itself by the idling stop function does not occur, the first electric load 44 at the time of engine restart is prevented.

  In addition, when it is determined that the booster circuit 11 is abnormal as described above, it is desirable to notify the user of the abnormality of the booster circuit 11 by turning on a display lamp disposed at a position where the user can visually recognize the booster circuit 11. In addition, when it is determined that the booster circuit 11 is abnormal, information indicating the abnormality of the booster circuit 11 is stored in the SRAM together with the time at that time, and the occurrence of the abnormality of the booster circuit 11 is subsequently determined based on the information. It is desirable to be able to confirm.

  As described above, in the voltage control apparatus 1 of the present embodiment, it is confirmed whether or not the booster circuit 11 is normal before the engine is stopped for the first time by the idling stop function from the engine start instruction from the user. When the booster circuit 11 is not normal, the idling stop function is invalidated. For this reason, the malfunction of the 1st electric load 44 which arises during the engine start by an idling stop function can be prevented reliably.

  In addition, since the operation of the booster circuit 11 is checked during driving of the starter motor in which the voltage of the battery 3 is greatly reduced, the operation of the booster circuit 11 can be confirmed without applying a voltage exceeding the rating to the first electric load 44. Since the voltage can be boosted relatively large, the determination accuracy of the operation confirmation can be improved. In addition, during the driving of the starter motor according to the engine start instruction from the user, the supply of electric power from the battery 3 to the electric load of the ACC system is generally cut off. Therefore, the operation of the booster circuit 11 can be confirmed without being affected by the state of the electrical load of the ACC system, and the determination accuracy can be further improved.

<2. Second Embodiment>
Next, a second embodiment will be described. The configurations of the electric system 100 and the voltage control apparatus 1 according to the second embodiment are the same as those in the first embodiment. In the first embodiment, the operation is confirmed by causing the booster circuit 11 to perform a boosting operation over the entire period during which the starter motor is driven. As described above, when the starter motor is driven, there are an initial state in which the load of the battery 3 is relatively large and a late state in which the load of the battery 3 is relatively small. In the initial state, the load of the battery 3 is relatively large. If the booster circuit 11 performs the boosting operation at this time, the load of the battery 3 is further increased and the voltage of the battery 3 is further decreased, which affects the drive of the starter motor. May give. That is, the starting performance of the engine may be deteriorated. For this reason, in the second embodiment, after the transition to the latter state where the load of the battery 3 is relatively small, the boosting operation is performed by the booster circuit 11 to confirm the operation.

  FIG. 5 is a diagram illustrating the relationship between the input voltage E1 and the output voltage E2 during operation confirmation when the booster circuit 11 is normal in the second embodiment.

  When a start instruction is given from the user and the starter motor is driven at time T11, the load on the battery 3 is in a relatively large initial state, and the input voltage E1 greatly decreases from the initial voltage Vbatt. Thereafter, at time T12, the torque necessary for the rotation of the engine decreases, and the battery 3 is in a late state in which the load is relatively small.

  Then, at the time T13 when the transition to the latter state is confirmed, the boosting operation is performed by the boosting circuit 11 to confirm the operation. As a result, the output voltage E2 increases after time T13. If the output voltage E2 has been boosted to the target value, it can be determined that the booster circuit 11 is normal. Thereafter, when the complete explosion of the engine is confirmed at time T14, the boosting operation of the booster circuit 11 is stopped.

  FIG. 6 is a diagram illustrating a flow of processing related to operation confirmation by the control unit 10 of the voltage control apparatus 1 according to the second embodiment. In this process, a process of confirming the transition to the late state (the process of step S21) is inserted between the process of step S12 and the process of step S13 in the process flow of the first embodiment shown in FIG. Is equivalent to

  That is, first, it is determined whether or not there is a start instruction from the user (step S11). If there is a start instruction from the user, it is determined whether or not the starter motor has been driven (step S12).

  When it is confirmed that the starter motor is driven, at this point in time, the boosting operation of the booster circuit 11 is not started, and it is determined whether or not the transition to the later state is performed in which the load of the battery 3 is relatively small (step S21). .

  The determination of the transition to the latter state is made by increasing the input voltage E1 to a predetermined voltage or higher, decreasing the current of the starter motor to a predetermined value or lower, or the rotational speed at which the engine speed is higher than a predetermined value (for example, 100 rpm). It can be done by becoming. The current of the starter motor can be determined by a signal from the starter motor unit 41. Further, the engine speed can be determined by a signal from the engine control device 43.

  When the transition to the latter state is confirmed, a signal is transmitted from the control unit 10 to the switch driving circuit 13 and the boosting operation by the boosting circuit 11 is started. The target value for boosting by the booster circuit 11 at this time is the voltage Valt that is an instruction voltage to the alternator after the engine is started. This is to reduce the fluctuation of the output voltage E2 after the engine is started. Note that the target value for boosting may be the initial voltage Vbatt (step S13).

  Subsequently, the output voltage E2 is confirmed. If output voltage E2 is equal to or higher than target value Voltage Valt (Yes in step S14), it is determined that booster circuit 11 is normal (step S15). Then, when the engine is completely detonated (Yes in step S16), the pressure increase instruction is stopped (step S17), and the process ends.

  On the other hand, if output voltage E2 is less than target value voltage Valt (No in step S14), boost circuit 11 is determined to be abnormal (step S18). Then, the boosting instruction is stopped (step S19), the idling stop function is disabled (step S20), and the process ends.

  As described above, in the voltage control device 1 according to the second embodiment, the operation of the booster circuit 11 is checked after shifting to a later state where the load of the battery 3 is relatively small. Without giving, it can be confirmed whether or not the booster circuit 11 is normal.

<3. Third Embodiment>
Next, a third embodiment will be described. The configurations of the electrical system 100 and the voltage control device 1 of the third embodiment are the same as those of the first embodiment. In the first and second embodiments, the operation is confirmed while the starter motor is driven in accordance with the engine start instruction from the user. On the other hand, in the third embodiment, the operation check of the booster circuit 11 is repeatedly performed after the complete explosion of the engine.

  FIG. 7 is a diagram illustrating a flow of processing related to operation confirmation by the control unit 10 of the voltage control apparatus 1 according to the third embodiment.

  First, the complete explosion of the engine that has been started according to the start instruction from the user is confirmed (step S31). Determination of the complete explosion of the engine is made by increasing the input voltage E1, stopping the starter motor, or when the engine speed reaches a predetermined value (for example, 500 rpm).

  When the complete explosion of the engine is confirmed, first, a completion flag that is an internal flag in the control unit 10 is turned OFF (step S32). The completion flag indicates whether or not the operation check of the booster circuit 11 has been completed. The completion flag = ON indicates completion of the operation check, and the completion flag = OFF indicates that the operation check is not completed.

  Subsequently, it is determined whether or not the completion flag is OFF (step S33). If the completion flag is OFF, it is further determined whether or not an execution condition for confirming the operation of the booster circuit 11 is satisfied. Determination is made (step S34). For example, when all the conditions such as “complete explosion of the engine or a predetermined time since the previous operation check”, “battery 3 voltage (input voltage E1) is in a normal range”, “alternator is normal”, etc. are all satisfied, It is determined that the execution condition is satisfied. If the execution condition is not satisfied at this time (No in step S34), the process proceeds to step S37.

  If the execution condition is satisfied (Yes in step S34), a boost determination process is performed (step S35). In this step-up determination process, the operation of whether or not the step-up circuit 11 is normal is confirmed. Details will be described later. When the boosting determination process is completed, the completion flag is turned ON (step S36), and the process proceeds to step S37.

  In step S37, it is determined whether the engine has been started and stopped by the idling stop function. This determination is made based on a signal from the idling stop device 2. When the engine is started and stopped by the idling stop function, the completion flag is turned off (step S38), and the process returns to step S33. On the other hand, if the engine is not started and stopped by the idling stop function, the process returns to step S33 as it is.

  In step S33, it is determined again whether or not the completion flag is OFF (step S33). As described above, when the completion flag is OFF and the execution condition is satisfied, a boost determination process (that is, operation check of the booster circuit 11) is performed. On the other hand, if the completion flag is ON, the process proceeds directly to step S37.

  Thus, the operation of the booster circuit 11 is confirmed only when the completion flag is OFF. Then, the completion flag is turned OFF immediately after the engine is started by the start instruction of the user and when the engine is started and stopped by the idling stop function. For this reason, every time the engine is started and stopped by the idling stop function, the operation is confirmed. In this way, immediately after the engine is started by the user's start instruction, the operation check is performed every time the engine is stopped and started by the idling stop function, so that even when the booster circuit 11 suddenly breaks down, Can be confirmed accurately. For this reason, the 1st electric load 44 can be operated stably, without producing the malfunction of the 1st electric load 44.

  In the boost determination process (step S35), two methods are selectively used as a method for confirming the operation of the booster circuit 11, and one of the two methods is employed depending on whether the alternator is generating power.

  FIG. 8 shows an input voltage E1 and an output voltage E2 when the booster circuit 11 is normal in an operation confirmation method (hereinafter referred to as “first confirmation method”) employed when the alternator is not generating power. It is a figure which shows the relationship.

  When the alternator is not generating power, the voltage of the battery 3, that is, the input voltage E1 is approximately the initial voltage Vbatt. Actually, the voltage of the battery 3 fluctuates because various electric loads operate while the vehicle is running. However, for convenience of explanation, the input voltage E1 is assumed to be constant at the initial voltage Vbatt.

  Normally, when the alternator is generating power, the input voltage E1 rises to a voltage Valt that is an instruction voltage to the alternator. In this case, since the output voltage E2 also rises to the voltage Valt, even if the output voltage E2 is raised to the voltage Valt, a voltage exceeding the rating is not given to the first electric load 44.

  Therefore, in the first confirmation method, in the state where the alternator is not generating power, the boosting circuit 11 performs a boosting operation using the voltage Valt as a target value, and the output of the voltage Valt from the input voltage E1 which is approximately the initial voltage Vbatt. A voltage E2 is generated. Then, if the state where the output voltage E2 is boosted to the target value of the voltage Valt or more continues for a predetermined time (for example, 1 second) or longer, the booster circuit 11 is determined to be normal. In the figure, boosting of the booster circuit 11 is started at time T21. Thereafter, when the state where the output voltage E2 is equal to or higher than the voltage Valt continues for 1 second or longer, it is determined that the output voltage E2 is normal, and the boosting operation is stopped at time T22.

  In this first checking method, since the operation of the booster circuit 11 is checked in a state where the alternator is not generating power, the voltage can be boosted relatively large when checking the normality of the booster circuit 11, so that the determination accuracy can be improved.

  On the other hand, FIG. 9 shows an input voltage E1 and an output voltage when the booster circuit 11 is normal in an operation confirmation method (hereinafter referred to as “second confirmation method”) employed when the alternator is generating power. It is a figure which shows the relationship with E2.

  When the alternator is generating power, the voltage Valt is designated as the instruction voltage, so the input voltage E1 is approximately the voltage Valt. In this state, if the boosting circuit 11 is caused to perform a boosting operation as a confirmation operation, a voltage exceeding the rating may be applied to the first electric load 44.

  For this reason, in the second confirmation method, while the alternator is generating power, the booster circuit 11 starts the boost operation with the voltage Valt (that is, the indicated voltage of the alternator before performing the operation confirmation) as a target value. An instruction is made to set the instruction voltage that is the target of power generation of the alternator to a voltage Valt2 that is lower than the voltage Valt before the operation check. By doing so, the input voltage E1 decreases to the voltage Valt2 lower than the voltage Valt during the operation check. Thereby, it is possible to cause the booster circuit 11 to substantially perform the boosting operation without applying a voltage exceeding the rating to the first electric load 44.

  Then, if the state where the output voltage E2 is boosted to the voltage value Valt that is the target value or more continues for a predetermined time (for example, 1 second in the present embodiment), it is determined that the booster circuit 11 is normal. In the drawing, at the time T31, since the booster 11 is instructed to decrease the voltage while starting the booster 11, the input voltage E1 decreases to the voltage Valt2. Thereafter, when the state where the output voltage E2 is equal to or higher than the voltage Valt continues for a predetermined time (for example, 1 second in this embodiment) or more, it is determined to be normal, and the boosting operation is stopped at time T32 and the alternator instruction voltage is returned. The input voltage E1 rises to the voltage Valt.

  In this second confirmation method, the target value for boosting of the booster circuit 11 in the operation check is set to the instruction voltage Valt before the operation check. Therefore, when the booster circuit 11 is normal, the output voltage E2 Fluctuations can be eliminated. For this reason, the operation can be confirmed without affecting the first electrical load 44.

  FIG. 10 is a diagram showing a detailed flow of the boost determination processing (step S35). First, it is determined whether the alternator is generating power (step S41). For example, if the input voltage E1 (that is, the voltage of the battery 3) is equal to or higher than a predetermined value (eg, 13.0 V), it is determined that the alternator is generating power. Further, based on a signal from the alternator unit 42, it may be determined whether or not the alternator is generating power.

  When the alternator is not generating power (No in step S41), the operation of the booster circuit 11 is confirmed by the first confirmation method.

  Specifically, a signal is transmitted from the control unit 10 to the switch driving circuit 13, and the boosting operation by the boosting circuit 11 is started with the voltage Valt as a target value (step S42). At the same time, a signal instructing prohibition of power generation is transmitted from the control unit 10 to the alternator unit 42 (step S43), and power generation of the alternator is prohibited. As a result, the alternator is prevented from suddenly generating power during the operation check of the booster circuit 11, and the operation check of the booster circuit 11 can be performed while maintaining the non-power generation state of the alternator.

  Next, when the output voltage E2 is confirmed and the output voltage E2 becomes equal to or higher than the target value of the voltage Valt (Yes in step S46), and the state continues for one second or longer (Yes in step S47), the booster circuit 11 is determined to be normal (step S48). Then, the boost instruction to the booster circuit 11 is stopped (step S49), and a signal instructing permission of power generation is transmitted to the alternator, and the alternator returns to the normal operation state (step S54). If the state where the output voltage E2 is equal to or higher than the voltage Valt is completed in less than 1 second (No in step S47), the determination is impossible and the process proceeds to step S54 as it is.

  Further, when the output voltage E2 is confirmed and the output voltage E2 is less than the target value of the voltage Valt (No in step S46) and the state continues for 1 second or longer (Yes in step S50), the booster circuit 11 is determined to be abnormal (step S51). Then, the boosting instruction to the booster circuit 11 is stopped (step S52), and a signal instructing invalidation is transmitted from the control unit 10 to the idling stop device 2, and the idling stop function is invalidated (step S52). S53). Furthermore, a signal instructing permission of power generation is transmitted to the alternator, and the alternator returns to the normal operation state (step S54). When the state where the output voltage E2 is less than the voltage Valt is completed in less than 1 second (No in step S50), the determination is impossible and the process proceeds to step S54 as it is.

  On the other hand, when the alternator is generating power (Yes in step S41), the operation of the booster circuit 11 is confirmed by the second confirmation method.

  Specifically, a signal is transmitted from the control unit 10 to the switch driving circuit 13, and the boosting operation by the boosting circuit 11 is started with the instruction voltage Valt of the alternator before performing the operation confirmation as a target value (step S44). At the same time, a signal for instructing to lower the instruction voltage is transmitted from the control unit 10 to the alternator unit 42, and the instruction voltage is set to a voltage Valt2 lower than the instruction voltage Valt before the operation check (step S45). As a result, the input voltage E1 decreases to the voltage Valt2.

  Next, when the output voltage E2 is confirmed and the output voltage E2 becomes equal to or higher than the target value of the voltage Valt (Yes in step S46), and the state continues for one second or longer (Yes in step S47), the booster circuit 11 is determined to be normal (step S48). Then, the boost command to the booster circuit 11 is stopped (step S49), and a signal for returning the command voltage to the voltage Valt is transmitted to the alternator, and the alternator returns to the normal operation state (step S54). . If the state where the output voltage E2 is equal to or higher than the voltage Valt is completed in less than 1 second (No in step S47), the determination is impossible and the process proceeds to step S54 as it is.

  Further, when the output voltage E2 is confirmed and the output voltage E2 is less than the target value of the voltage Valt (No in step S46) and the state continues for 1 second or longer (Yes in step S50), the booster circuit 11 is determined to be abnormal (step S51). Then, the boosting instruction to the booster circuit 11 is stopped (step S52), and a signal instructing invalidation is transmitted from the control unit 10 to the idling stop device 2, and the idling stop function is invalidated (step S52). S53). Further, a signal for returning the instruction voltage to the voltage Valt is transmitted to the alternator, and the alternator returns to the normal operation state (step S54). When the state where the output voltage E2 is less than the voltage Valt is completed in less than 1 second (No in step S50), the determination is impossible and the process proceeds to step S54 as it is.

  As described above, in the third embodiment, since the operation of the booster circuit 11 is checked after the complete explosion of the engine, it is determined whether or not the booster circuit 11 is normal without affecting the engine start performance. I can confirm.

  In addition, there are a first confirmation method and a second confirmation method as methods for confirming the operation of the booster circuit 11, and either method is adopted depending on whether the alternator is generating power. Specifically, the first confirmation method is adopted when the alternator is not generating power, and the second confirmation method is adopted when the alternator is generating power. As described above, since the operation of the booster circuit is checked by an appropriate method according to the power generation status of the alternator, the operation check of the booster circuit 11 can be executed regardless of the power generation status of the alternator.

<4. Modification>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible. Below, such a modification is demonstrated. All forms including those described in the above embodiment and those described below can be combined as appropriate.

  In the above-described embodiment, the voltage control device 1 and the idling stop device 2 have different configurations. However, they may be housed and integrated in the same casing to form a single ECU (Electronic Control Unit). In this case, you may implement | achieve the control part 10 of the voltage control apparatus 1, and the microcomputer of the idling stop apparatus 2 with one microcomputer. According to this, cost can be reduced.

  In the third embodiment, the first confirmation method and the second confirmation method are selectively used as the method of confirming the operation of the booster circuit 11. However, only one of the first confirmation method and the second confirmation method may be employed. . In addition, if the second confirmation method is employed in a vehicle that regenerates energy with an alternator when the vehicle decelerates, the operation can be confirmed during power generation during energy regeneration when the vehicle decelerates. In addition, the operation of the booster circuit 11 can be confirmed.

  In the above-described embodiment, whether or not the booster circuit 11 is normal is determined based on whether or not the output voltage E2 is equal to or higher than the boost target value. On the other hand, whether or not the booster circuit 11 is normal may be determined based on whether or not the difference between the output voltage E2 and the boost target value is less than a predetermined value.

  Further, in the above-described embodiment, it has been described that various functions are realized in software by the arithmetic processing of the CPU according to the program. However, some of these functions are realized by an electrical hardware circuit. Also good.

DESCRIPTION OF SYMBOLS 1 Voltage control apparatus 2 Idling stop apparatus 3 Battery 10 Control part 11 Booster circuit 13 Switch drive circuit 44 1st electric load 91 Start switch

Claims (10)

A voltage control device mounted on a vehicle having an idling stop function for automatically stopping / starting an engine when a predetermined condition is satisfied, and controlling a voltage supplied to an electric load of the vehicle,
A boosting circuit that boosts a voltage supplied from a battery of the vehicle and supplies the boosted voltage to the electric load during startup of the engine by the idling stop function;
Between the start instruction of the engine from the user until the engine is stopped for the first time by the idling stop function, the booster circuit performs a boost operation to check whether the booster circuit is normal or not. Confirmation means;
Invalidating means for invalidating the idling stop function when the booster circuit is not normal;
A voltage control device comprising: The voltage control device according to claim 1,
The voltage control apparatus according to claim 1, wherein the confirmation unit confirms the operation of the booster circuit during driving of a starter motor that starts the engine according to a start instruction from the user. The voltage control device according to claim 2,
A transition determination means for determining that the battery load has shifted from a relatively large initial state to a late state in which the battery load is relatively small during driving of the starter motor;
Further comprising
The voltage control apparatus according to claim 1, wherein the confirmation unit confirms the operation of the booster circuit after transitioning to the late state during driving of the starter motor. The voltage control device according to claim 1,
The voltage control device according to claim 1, wherein the confirmation means confirms the operation of the booster circuit after the complete explosion of the engine. The voltage control device according to claim 4,
The voltage control device according to claim 1, wherein the confirmation unit confirms the operation of the booster circuit in a state where a generator that stores generated power in the battery is not generating power. The voltage control device according to claim 4,
The checking means is configured to check an instruction voltage that is a target of power generation of the generator before performing the operation check when performing the operation check of the booster circuit during power generation of the generator that stores the generated power in the battery. A voltage control device characterized in that the generator is instructed to be lower. The voltage control apparatus according to claim 6,
The voltage control apparatus according to claim 1, wherein the confirmation unit sets a target of boosting of the booster circuit in the operation confirmation as an instruction voltage before the operation confirmation. The voltage control device according to claim 4,
The confirmation means includes
When the generator that accumulates the generated power in the battery is generating power, when the operation check of the booster circuit is performed, the instruction voltage that is the target of power generation of the generator is before the operation check. Instruct the generator to lower,
When the generator is not generating power, the operation of the booster circuit is checked while maintaining the non-power generation state of the generator. The voltage control device according to any one of claims 4 to 8,
The voltage control device according to claim 1, wherein the confirmation unit further performs the operation confirmation every time the engine is stopped and started by the idling stop function. In a vehicle having an idling stop function for automatically stopping / starting the engine when a predetermined condition is satisfied, the idling stop function is invalidated,
Whether the booster circuit is normal by causing the booster circuit to boost the voltage supplied from the vehicle battery during the engine start by the idling stop function and supply the boosted voltage to the electric load of the vehicle. A confirmation process to confirm whether or not,
An invalidation step of invalidating the idling stop function when the booster circuit is not normal;
With
The idling stop function invalidating method, wherein the checking step is performed from a start instruction of the engine from a user until the engine is stopped for the first time by the idling stop function.