JP5545459B2 - Engine automatic stop / start control device - Google Patents

Description

  The present invention relates to an engine automatic stop / start control device that performs idle stop control for automatically stopping an engine when a predetermined automatic stop condition is satisfied and restarting the engine when a predetermined restart condition is satisfied. .

  In recent years, some vehicles equipped with an engine (internal combustion engine) perform idle stop control for the purpose of reducing fuel consumption and exhaust emissions. In this idle stop control, for example, when the driver stops or decelerates the vehicle while the engine is running and the automatic stop condition is satisfied, the engine is automatically stopped, and then the engine is automatically stopped (during idle stop). ) When the driver performs an operation to start or accelerate the vehicle and the restart condition is satisfied, the engine is automatically cranked by the starter and restarted.

  In a system that performs such idle stop control, for example, as described in Patent Document 1 (Japanese Patent Laid-Open No. 2006-233917), there is an abnormality in the idle stop control ECU and the idle stop control ECU. And an engine control ECU that monitors whether there is an abnormality in the idle stop control ECU. The engine control ECU turns on / off power supply from the battery to the idle stop control ECU. There is one in which the starter is stopped by stopping energization to the starter by turning off the relay and stopping the power supply to the idle stop control ECU.

Japanese Patent Laid-Open No. 2006-233917

  By the way, when the idle stop control ECU is abnormal, it is preferable to quickly stop the starter. However, in the technique disclosed in Patent Document 1, when an abnormality is detected in the idle stop control ECU, the power supply relay is turned off to stop the power supply to the idle stop control ECU, thereby stopping the energization of the starter. Since the starter is brought into a stop state, the time from when the abnormality of the idle stop control ECU is detected until the starter stops is prolonged, and the starter is quickly stopped when the idle stop control ECU is abnormal. There is a problem that it cannot be put into a state.

  Further, in order to stop power supply to the idle stop control ECU when an abnormality is detected in the idle stop control ECU, the CPU of the idle stop control ECU is reset to return the idle stop control ECU to normal. In order to drive the starter, it is necessary to temporarily stop the power supply to the idle stop control ECU and then restart the power supply, reset the CPU of the idle stop control ECU, and return the idle stop control ECU to normal operation. Yes, it takes a long time to detect the abnormality of the idle stop control ECU and restore the normal operation of the idle stop control ECU to drive the starter. For example, the engine can be restarted early due to an idle stop at an intersection. The engine cannot be restarted early if it is necessary to There is a possibility that the discomfort to the driver.

  Accordingly, the problem to be solved by the present invention is that when an abnormality in the idle stop control system is detected, the starter can be quickly brought into a stopped state, and the idle stop control system can be quickly returned to normal to An object of the present invention is to provide an engine automatic stop / start control device that can be restarted early.

  In order to solve the above-mentioned problem, the invention according to claim 1 automatically stops the engine when a predetermined automatic stop condition is satisfied, and drives the starter (18, 28) when the predetermined restart condition is satisfied. Then, in the engine automatic stop / start control device that performs idle stop control for restarting the engine, the starter (18, 28) is controlled by controlling the starter relay (17, 31, 32) for turning on / off the starter (18, 28). 28), the microcomputer for idle stop control (hereinafter referred to as "the microcomputer for idle stop control") (14, 46), and whether there is an abnormality in the microcomputer for idle stop control (14, 46). A monitoring IC (13, 45) for monitoring with two systems of the signal line (22) and the second signal line (23) is one electronic control unit (15). When the monitoring IC (13, 45) detects an abnormality in the idle stop control microcomputer (14, 46), the monitoring IC (13, 45) turns off the starter relay (17, 31, 32) and turns off the starter (18, 28). The driving is prohibited and the idle stop control microcomputer (14, 46) is reset.

  In this configuration, the monitoring IC can monitor whether there is an abnormality in the microcomputer for idle stop control with two systems of the first signal line and the second signal line. Can be increased. Also, when an abnormality in the microcomputer for idle stop control is detected, the starter relay can be turned off directly (turning off the power to the starter) instead of the power supply relay, so that starter drive can be prohibited. Can be stopped. Furthermore, when an abnormality is detected in the idle stop control microcomputer, the idle stop control microcomputer can be quickly reset without stopping the power supply to the idle stop control microcomputer. Can be quickly restored to normal and the starter can be driven, and the engine can be restarted early.

  In this case, as in claim 2, the engine control microcomputer (hereinafter referred to as “engine control microcomputer”) (13) that controls the engine functions as a monitoring IC, and the idle stop control microcomputer (14) The presence or absence of an abnormality in the engine control microcomputer (13) may be monitored. The engine control microcomputer that knows the vehicle's running state functions as a monitoring IC, so that the starter can be driven quickly according to the running state (for example, starter start prohibition during running or engine equipment failure). Can be banned. Further, the idle stop control microcomputer can detect an abnormality of the engine control microcomputer (for example, an abnormality of the electronic throttle control), and can prohibit erroneous starter driving when the engine control is abnormal.

  According to a third aspect of the present invention, the starter relay includes a plurality of starter relays (31, 32) that operate independently to control the starter (28), and the plurality of starter relays (31, 32). One of the starter relays (31) may be driven by the engine control microcomputer (13), and the other starter relay (32) may be driven by the idle stop control microcomputer (14). In this way, in a system that controls a starter by controlling a plurality of starter relays, when the engine control microcomputer detects an abnormality in the idle stop control microcomputer, it turns off one of the starter relays and turns off the starter relay. Driving can be prohibited.

  According to a fourth aspect of the present invention, as a starter relay, a starter relay for solenoid (31) for turning on / off the energization to the solenoid (29) for pushing out the pinion of the starter (28), and the pinion are rotationally driven. And a motor starter relay (32) for turning on / off the energization of the starter motor (30) for controlling the engine (hereinafter referred to as "engine control microcomputer") (13, 46) has a means (44) for capturing the output signal of the engine rotation sensor (43), and when the engine rotation speed detected based on the output signal of the engine rotation sensor (43) becomes a predetermined value or less. The solenoid starter relay (31) is turned on so that the pinion meshes with the engine ring gear. There.

  When the engine is stopped, the engine rotation speed usually decreases rapidly or becomes unstable. Therefore, it is preferable to push out the pinion and mesh with the ring gear immediately before the engine stops. For this reason, if the starter relay for the solenoid is turned on and the pinion is engaged with the ring gear when the engine rotational speed becomes a predetermined value or less as in claim 4, the engine immediately before the engine stops (next engine The pinion can be engaged with the ring gear before starting). As a result, even if the idle stop control microcomputer becomes abnormal immediately after the engine stops, the pinion can be kept in mesh with the ring gear, and the engine can be restarted early after the idle stop control microcomputer returns from the abnormal state. Can be started.

  The engine control microcomputer accurately detects the crank angle (crankshaft rotation angle) and cam angle (camshaft rotation angle) for the purpose of reducing exhaust gas, etc. Since it is necessary to appropriately control the ignition timing and the like, a means for accurately detecting the crank angle and the cam angle (a means for capturing the output signal of the engine rotation sensor) is provided. For this reason, it is not necessary to newly provide a means for detecting an accurate crank angle and cam angle required for the engagement of the pinion.

  Further, according to the fifth aspect, the idle stop control microcomputer (14) resets the engine control microcomputer (13) when detecting an abnormality of the engine control microcomputer (13), and the engine control microcomputer ( 13) The idle stop control microcomputer (14) is reset from the reset until the engine is normally started, and when the engine control microcomputer (13) is reset, the starter relay drive permission from the engine control microcomputer (13) is permitted. The signal becomes the drive prohibiting side of the starter relay (17, 31, 32), and the starter relay drive signal from the idle stop control microcomputer (14) is reset when the idle stop control microcomputer (14) is reset. , 32) on the drive stop side. In this way, the vehicle cannot run in a state where the engine control microcomputer is not operating, so the engine control microcomputer is the main microcomputer (if the engine control microcomputer does not operate, the operation of the idle stop control microcomputer And a configuration in which driving of the starter is also prohibited.

  Further, as in claim 6, the engine control microcomputer (13) outputs a starter relay drive permission signal from the engine control microcomputer (13) when the engine is not stopped. , 32) may be set to the drive prohibited side. Since it is not necessary to drive the starter when the engine is not stopped, the probability of preventing erroneous starter driving can be increased by setting the starter relay drive permission signal to the start prohibition side of the starter relay.

  Further, as the first signal line, a direct line (22) for transmitting a watchdog signal from the idle stop control microcomputer (14, 46) to the monitoring IC (13, 45) is provided as the first signal line. As a second signal line, it is preferable to provide a communication line (23) for transmitting and receiving information dedicated to monitoring between the idle stop control microcomputer (14, 46) and the monitoring IC (13, 45). In this way, the monitoring IC can monitor whether there is an abnormality in the microcomputer for idling stop control with two systems of the direct line for transmitting the watchdog signal and the communication line for transmitting and receiving the information dedicated for monitoring. It is possible to improve the reliability of abnormality detection of the microcomputer for idle stop control.

  In this case, as in claim 8, the communication line (23) for transmitting and receiving the monitoring-dedicated information includes the idle stop control microcomputer (14, 46) and the monitoring IC (13, 45) without using the transceiver IC. May be a communication line that is connected in a one-to-one relationship. By not using bus communication between electronic control devices such as CAN (Controller Area Network) against the increase in communication load due to communication of information dedicated to monitoring, the effect of external noise can be reduced, and the transceiver Since high-speed communication is possible without using an IC (for example, a CAN transceiver IC), communication can be realized at low cost. In addition, since it is possible to communicate one-to-one between the microcomputer for idle stop control and the monitoring IC and there is no communication information from other electronic control devices, even if the communication load increases, the communication with other electronic control devices is increased. There is no effect on communication.

  According to a ninth aspect of the present invention, the starter relay drive permission signal from the monitoring IC (13, 45) is on the drive permission side of the starter relay (17, 31, 32) and the idle stop control microcomputer (14, 46). AND circuit (20, 21, 33, 34, 37, 38) for turning on the starter relay (17, 31, 32) when the starter relay drive signal from the starter relay (17, 31, 32) is on the drive side 39), and the monitoring IC (13, 45) receives the starter relay drive permission signal from the monitoring IC (13, 45) when it detects an abnormality in the idle stop control microcomputer (14, 46). The starter relays (17, 31, 32) may be turned off by setting the relays (17, 31, 32) to the drive prohibited side. In this way, it is possible to inhibit the starter relay by turning off the starter relay when an abnormality is detected in the idle stop control microcomputer with an inexpensive configuration.

  In this case, as in claim 10, in the AND circuit, a plurality of transistors (37, 38, 39) are arranged in series between the power supply (11) and the starter relay (31, 32), and one of the transistors (37) is driven by a starter relay drive permission signal from the monitoring IC (13, 45), and the other transistor (38, 39) is driven by a starter relay drive signal from the idle stop control microcomputer (14, 46). It may be configured to be driven by. In this way, an AND circuit can be realized using the transistor driven by the monitoring IC and the transistor driven by the idle stop control microcomputer, and a plurality of transistors are arranged in series. Therefore, even when one transistor is turned on, the starter relay can be turned off by turning off the other transistor.

  Further, as a starter relay, the starter relay includes a plurality of starter relays (31, 32) that individually operate to control the starter (28), and is provided with a monitoring IC (13, 45). The transistor driven by the starter relay drive permission signal is provided with one common transistor (37) for the plurality of starter relays (31, 32), and the starter relay from the idle stop control microcomputer (14, 46). As for the transistors driven by the drive signal, one transistor (38, 39) may be provided for each starter relay with respect to the plurality of starter relays (31, 32). In this way, the transistor driven by the monitoring IC can be shared (shared) with a plurality of starter relays, and an inexpensive configuration can be achieved.

  Further, as in claim 12, the monitoring IC (13, 45) may have a function of monitoring the drive terminal of the starter relay (17, 31, 32). In this way, the actual drive state of the starter relay can be confirmed based on the state of the drive terminal of the starter relay. Even if the starter relay is not driven due to a circuit failure or the like, it can be done early. Can be detected.

FIG. 1 is a diagram showing a schematic configuration of a control system in Embodiment 1 of the present invention. FIG. 2 is a diagram for explaining the logical relationship between each microcomputer output and the STA terminal output. FIG. 3 is a flowchart showing the flow of processing of the control routine. FIG. 4 is a diagram illustrating a schematic configuration of a control system according to the second embodiment. FIG. 5 is a diagram illustrating a schematic configuration of a control system according to the third embodiment. FIG. 6 is a diagram illustrating a schematic configuration of a control system according to the fourth embodiment. FIG. 7 is a diagram illustrating a schematic configuration of a control system according to the fifth embodiment.

  Hereinafter, some embodiments embodying the mode for carrying out the present invention will be described.

A first embodiment of the present invention will be described with reference to FIGS.
First, a schematic configuration of the control system will be described based on FIG.
A power supply IC 12 connected to a battery 11 (power source), an engine control microcomputer (hereinafter referred to as “engine control microcomputer”) 13, and an idle stop control microcomputer (hereinafter referred to as “idle stop control microcomputer”) 14 and the like are mounted on one electronic control unit (hereinafter referred to as “ECU”) 15.

  A plurality of other electronic control devices 16 are connected to the CAN terminal of the ECU 15, and information is transmitted and received between the ECU 15 and the other plurality of electronic control devices 16 by CAN (Controller Area Network) communication. . The starter relay 17 is connected to the STA terminal of the ECU 15 (the drive terminal of the starter relay 17). By turning on / off the starter relay 17, the energization from the battery 11 to the starter motor 19 of the starter 18 is turned on / off. It is supposed to turn off.

  The ECU 15 automatically stops the engine when the driver stops or decelerates the vehicle while the engine (not shown), which is an internal combustion engine, is operating, and the automatic stop condition is satisfied, and then the engine is automatically stopped. An idle stop that automatically drives the starter 18 and cranks and restarts the engine when the driver performs an operation to start or accelerate the vehicle (during idle stop) and the restart condition is satisfied. Take control.

  The engine control microcomputer 13 controls the fuel injection amount, ignition timing, intake air amount (throttle opening), and the like of the engine. The idle stop control microcomputer 14 controls the starter relay 17 on / off to control the starter 18. Control the drive. The starter relay drive permission signal DA from the engine control microcomputer 13 and the starter relay drive signal DB from the idle stop control microcomputer 14 are input to the NAND circuit 20, and the output signal DC of the NAND circuit 20 is the transistor 21 (for example, MOSFET etc.). The transistor 21 is disposed between the battery 11 and the starter relay 17, and the starter relay 17 is turned on / off by turning on / off the transistor 21.

  In this case, the NAND circuit 20, the transistor 21 and the like function as an AND circuit, the starter relay drive permission signal DA from the engine control microcomputer 13 is at the H level (drive permission side of the starter relay 17), and the idle stop control microcomputer. When the starter relay drive signal DB from 14 is at the H level (drive side of the starter relay 17), the output signal DC of the NAND circuit 20 is at the L level and the transistor 21 is turned on. As a result, the starter relay 17 is turned on (energization to the starter motor 19 is turned on) and the starter 18 is driven.

  On the other hand, the starter relay drive permission signal DA from the engine control microcomputer 13 is at the L level (starter relay 17 drive prohibited side) or the starter relay drive signal DB from the idle stop control microcomputer 14 is at the L level (starter relay 17 drive). (Stop side), the output signal DC of the NAND circuit 20 becomes H level and the transistor 21 is turned off. As a result, the starter relay 17 is turned off (energization to the starter motor 19 is turned off), and the drive of the starter 18 is stopped.

  Further, the engine control microcomputer 13 functions as a monitoring IC that monitors whether the idle stop control microcomputer 14 is abnormal. In this embodiment, a direct line 22 (first signal line) for transmitting a watchdog signal from the idle stop control microcomputer 14 to the engine control microcomputer 13 is provided, and the idle stop control microcomputer 14 and the engine control A communication line 23 (second signal line) for transmitting / receiving information dedicated to monitoring to / from the microcomputer 13 is provided.

The communication line 23 that transmits and receives information dedicated to monitoring is a communication line that connects the idle stop control microcomputer 14 and the engine control microcomputer 13 on a one-to-one basis without using a transceiver IC. By not using bus communication between electronic control devices such as CAN for the increase in communication load due to communication of information dedicated to monitoring, the effect of external noise can be reduced, and a transceiver IC (for example, CAN transceiver) Since high-speed communication is possible without using an IC, communication can be realized at low cost. In addition, since the idle stop control microcomputer 14 and the engine control microcomputer 13 can communicate one-to-one and there is no communication information from the other electronic control device 16, even if the communication load increases, other electronic Communication with the control device 16 is not affected.
The engine control microcomputer 13 monitors the presence / absence of an abnormality in the idle stop control microcomputer 14 by two systems of the direct line 22 and the communication line 23 as follows.

(1) Monitoring of the idle stop control microcomputer 14 using the solid wire 22 The engine control microcomputer 13 is provided with a watch dog timer (not shown) for monitoring the operation of the idle stop control microcomputer 14 to When the stop control microcomputer 14 is operating normally, a watchdog signal for clearing the watchdog timer is periodically output from the idle stop control microcomputer 14 to the engine control microcomputer 13 via the direct line 22. However, when the operation of the idle stop control microcomputer 14 becomes abnormal, the watchdog timer is not cleared. Therefore, when the watchdog timer counts out a predetermined time and times out, the engine control microcomputer 13 Abnormal operation of stop control microcomputer 14 It is determined that there is a reset (restart) the idle stop control microcomputer 14 outputs a reset signal for resetting the idle stop control microcomputer 14.

(2) Monitoring of the idle stop control microcomputer 14 using the communication line 23 The engine control microcomputer 13 outputs a calculation query to the idle stop control microcomputer 14 via the communication line 23, and the idle stop control microcomputer 14 calculates. The calculation result (answer) for the question is output to the engine control microcomputer 13 via the communication line 23. Then, the engine control microcomputer 13 checks the calculation result of the idle stop control microcomputer 14 in response to the calculation question, and determines whether or not the idle stop control microcomputer 14 has a calculation abnormality. Note that the method of monitoring the idle stop control microcomputer 14 using the communication line 23 is not limited to this, and may be appropriately changed. For example, the engine control microcomputer 13 and the idle stop control microcomputer 14 respectively. The same signal is input and A / D converted, and the engine control microcomputer 13 compares the A / D conversion values of the microcomputers 13 and 14 to determine whether the idle stop control microcomputer 14 has an A / D conversion abnormality. It may be determined.

  In the method (1), an operation abnormality (abnormal processing timing) of the idle stop control microcomputer 14 is determined by monitoring the watchdog signal. For example, a part of the control program of the idle stop control microcomputer 14 is used. Even if only this routine becomes abnormal, the watchdog signal may be periodically output to reset the watchdog timer. Even if the arithmetic processing of the idle stop control microcomputer 14 is abnormal, if the periodic processing is normal, no abnormality appears in the watchdog signal. Therefore, strictly speaking, even if the watchdog signal is normal, it cannot be said that the idle stop control microcomputer 14 is operating normally. Therefore, by adopting the method (2), it becomes possible to detect an abnormality (for example, an operation abnormality) that cannot be detected only by monitoring the watchdog signal, and the reliability of the abnormality detection of the idle stop control microcomputer 14 is improved. Can be made.

  In the first embodiment, the engine control microcomputer 13 executes a control routine shown in FIG. 3 to be described later, so that when the abnormality of the idle stop control microcomputer 14 is detected, the starter relay drive permission signal DA is set to the L level (starter By switching to the drive inhibition side of the relay 17 and turning off the transistor 21, the starter relay 17 is turned off (energization to the starter motor 19 is turned off) to inhibit the starter 18 from being driven and to the idle stop control microcomputer 14. A reset signal is output to reset the idle stop control microcomputer 14. As a result, when an abnormality is detected in the idle stop control microcomputer 14, the starter 18 is promptly stopped and the idle stop control microcomputer 14 is quickly reset. Even when the idle stop control microcomputer 14 is normal, it is determined that it is not necessary to drive the starter 18 during engine operation (when the engine is not stopped), and the starter relay drive permission signal DA is determined. Is switched to the L level to turn off the starter relay 17 and inhibit the starter 18 from being driven.

  The engine control microcomputer 13 has a function of monitoring the STA terminal (drive terminal of the starter relay 17). As a result, the actual driving state of the starter relay 17 can be confirmed based on the state of the STA terminal, and even if the starter relay 17 is not driven due to a circuit failure or the like, it can be detected early. it can.

  On the other hand, the idle stop control microcomputer 14 monitors whether the engine control microcomputer 13 is abnormal as follows. The idle stop control microcomputer 14 is provided with a watchdog timer (not shown) for monitoring the operation of the engine control microcomputer 13. When the engine control microcomputer 13 is operating normally, the engine control microcomputer 13 periodically outputs a watchdog signal for clearing the watchdog timer to the idle stop control microcomputer 14 via the direct line 24, but the watchdog timer is cleared when the operation of the engine control microcomputer 13 becomes abnormal. When the watchdog timer counts out a predetermined time and times out, the idle stop control microcomputer 14 determines that the operation of the engine control microcomputer 13 is abnormal, and the engine control microcomputer Reset signal to reset (restart) 13 Output to the reset the engine control microcomputer 13.

  The power supply IC 12 also monitors the engine control microcomputer 13 for an abnormality as follows. The power supply IC 12 is provided with a watchdog timer (not shown) for monitoring the operation of the engine control microcomputer 13. When the engine control microcomputer 13 is operating normally, the engine control microcomputer 13 starts the watchdog timer. A watchdog signal for clearing the timer is periodically output to the power supply IC 12 via the direct line 25. However, when the operation of the engine control microcomputer 13 becomes abnormal, the watchdog timer is not cleared. When a predetermined time is counted and timed out, the power supply IC 12 determines that the operation of the engine control microcomputer 13 is abnormal and outputs a reset signal for resetting (restarting) the engine control microcomputer 13 Then, the engine control microcomputer 13 is reset.

  As described above, the idle stop control microcomputer 14 resets the engine control microcomputer 13 when an abnormality of the engine control microcomputer 13 is detected, but until the engine control microcomputer 13 is reset and normally started. The idle stop control microcomputer 14 is also reset. Further, when the engine control microcomputer 13 is reset, since the output of the engine control microcomputer 13 becomes HiZ (high impedance), the starter relay drive permission signal DA is set to the L level by the pull-down resistor 26 (starter relay 17 drive prohibited side). When the idle stop control microcomputer 14 is reset, the output of the idle stop control microcomputer 14 becomes HiZ, so that the starter relay drive signal DB becomes L level (drive stop side of the starter relay 17) by the pull-down resistor 27. It has become.

  As shown in FIG. 2, when the output of the engine control microcomputer 13 is HiZ (when the engine control microcomputer 13 is reset), the starter relay drive permission signal DA is at the L level (the start prohibition side of the starter relay 17). Therefore, when the output (starter relay drive signal DB) of the microcomputer 14 for idle stop control is either H level or L level, the starter relay 17 is turned off and the starter 18 is prohibited from being driven. On the other hand, when the output of the microcomputer 14 for idle stop control is HiZ (when the microcomputer 14 for idle stop control is reset), the starter relay drive signal DB becomes L level (drive stop side of the starter relay 17). When the output of the control microcomputer 13 (starter relay drive permission signal DA) is either H level or L level, the starter relay 17 is turned off and the starter 18 is prohibited from driving.

Thus, since the vehicle cannot travel in a state where the engine control microcomputer 13 is not operated, the engine control microcomputer 13 is the main microcomputer (if the engine control microcomputer 13 does not operate, the idle stop control microcomputer 14 The operation is prohibited and the drive of the starter 17 is also prohibited).
The processing contents of the control routine of FIG. 3 executed by the engine control microcomputer 13 in the first embodiment will be described below.

  The control routine shown in FIG. 3 is repeatedly executed at a predetermined cycle during the power-on period of the engine control microcomputer 13. When this routine is started, first, in step 101, monitoring of the idle stop control microcomputer 14 using the direct line 22 and monitoring of the idle stop control microcomputer 14 using the communication line 23 are executed (start). To do.

  Thereafter, the process proceeds to step 102 where at least one of monitoring of the idle stop control microcomputer 14 using the direct line 22 and monitoring of the idle stop control microcomputer 14 using the communication line 23 is performed. It is determined whether an abnormality of the microcomputer 14 has been detected.

  If it is determined in step 102 that an abnormality in the idle stop control microcomputer 14 has been detected, the process proceeds to step 103 where the starter relay drive permission signal DA is switched to the L level (starter relay 17 drive prohibited side). As a result, the starter relay 17 is turned off (energization to the starter motor 19 is turned off) to prohibit the starter 18 from being driven.

Thereafter, the process proceeds to step 104, where a reset signal is output to the idle stop control microcomputer 14 to reset the idle stop control microcomputer 14.
Thereafter, the process proceeds to step 105, and after waiting for a time (for example, 50 ms) required for the idle stop control microcomputer 14 to restart, this routine is terminated.

  On the other hand, if it is determined in step 102 that an abnormality in the idle stop control microcomputer 14 has not been detected (the idle stop control microcomputer 14 is normal), the process proceeds to step 106 to determine whether or not the engine is stopped. Determine whether.

  If it is determined in step 106 that the engine is stopped, the routine proceeds to step 107, where the starter relay drive permission signal DA is switched to the H level (starter relay 17 drive permission side), and the starter 18 is driven. To give permission. In this case, when the starter relay drive signal DB is switched to the H level (drive side of the starter relay 17) by the idle stop control microcomputer 14, the starter relay 17 is turned on (energization to the starter motor 19 is turned on). The starter 18 is driven.

  On the other hand, if it is determined in step 106 that the engine is not stopped (engine is running), the routine proceeds to step 108 where it is determined that there is no need to drive the starter 18 and the starter relay drive permission is given. The signal DA is switched to the L level (starter relay 17 drive prohibited side). As a result, the starter relay 17 is turned off (energization to the starter motor 19 is turned off) to prohibit the starter 18 from being driven, thereby increasing the probability of preventing erroneous starter 18 drive.

  In the first embodiment described above, the engine control microcomputer 13 monitors whether there is an abnormality in the idle stop control microcomputer 14 using the two lines of the direct line 22 and the communication line 23. The abnormality detectability of the microcomputer 14 can be improved. Further, when an abnormality of the idle stop control microcomputer 14 is detected, the starter relay 17 is directly turned off (the power supply to the starter motor 19 is turned off) instead of the power supply relay, thereby prohibiting the starter 18 from being driven. Therefore, the starter 18 can be quickly brought into a stopped state. Further, when an abnormality of the idle stop control microcomputer 14 is detected, the idle stop control microcomputer 14 is promptly reset without stopping the power supply to the idle stop control microcomputer 14. The starter 18 can be driven by quickly returning the control microcomputer 14 to the normal state, and the engine can be restarted early.

  In the first embodiment, since the engine control microcomputer 13 that grasps the vehicle running state functions as a monitoring IC, the running state (for example, starter start prohibition during running or engine engine failure) Etc.), the starter 18 can be prohibited from being driven at an early stage. Since the idle stop control microcomputer 14 monitors the engine control microcomputer 13 for an abnormality, the idle stop control microcomputer 14 detects an abnormality in the engine control microcomputer 13 (for example, an electronic throttle control abnormality). This can be detected, and erroneous starter 18 drive can be prohibited when engine control is abnormal.

  In the first embodiment, the NAND circuit 20, the transistor 21 and the like function as an AND circuit, and when an abnormality of the idle stop control microcomputer 14 is detected, the starter relay drive permission signal DA is set to the L level (starter relay 17). Since the starter relay 17 is turned off (energization to the starter motor 19 is turned off) and the starter 18 is prohibited from being driven, the idling stop control microcomputer 14 malfunctions with an inexpensive configuration. At the time of detection, the starter relay 17 can be turned off to prohibit the starter 18 from being driven.

  Next, Embodiment 2 of the present invention will be described with reference to FIG. However, parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified, and parts different from those in the first embodiment are mainly described.

  In the second embodiment, as shown in FIG. 4, the starter 28 includes a solenoid 29 for pushing out a pinion (not shown) and a starter motor 30 for driving the pinion to rotate. Also, a first starter relay 31 (a starter relay for solenoid) that turns on / off the energization from the battery 11 to the solenoid 29, and a second starter relay 32 that turns on / off the energization from the battery 11 to the starter motor 30. (Starter relay for motor) are provided so as to operate independently.

  Further, a first transistor 33 is disposed between the battery 11 and the first starter relay 31, and a second transistor 34 is disposed between the battery 11 and the second starter relay 32. The first transistor 33 is turned on / off by the starter relay drive permission signal DA from the engine control microcomputer 13, and the second transistor 34 is turned on / off by the starter relay drive signal DB from the idle stop control microcomputer 14. Is done.

  In this case, when the starter relay drive permission signal DA from the engine control microcomputer 13 is at the L level (the drive permission side of the first starter relay 31), the first transistor 33 is turned on and the first starter relay is turned on. 31 is turned on (energization to the solenoid 29 is turned on). When the starter relay drive signal DB from the idle stop control microcomputer 14 is at the L level (the drive side of the second starter relay 32), the second transistor 34 is turned on, and the second starter relay 32 is turned on. Turned on (energization to starter motor 30 is turned on).

  In the second embodiment, the transistors 33 and 34 and the like function as an AND circuit, the starter relay drive permission signal DA from the engine control microcomputer 13 is at L level, and the starter relay drive signal DB from the idle stop control microcomputer 14 is. When L is at the L level, both the first and second starter relays 31 and 32 are turned on (the energization to both the solenoid 29 and the starter motor 30 is turned on), and the starter 28 is normally driven. ing.

  When the engine control microcomputer 13 detects an abnormality in the idle stop control microcomputer 14, the engine control microcomputer 13 switches the starter relay drive permission signal DA to the H level (the drive prohibition side of the first starter relay 31) to turn off the transistor 33. As a result, the first starter relay 31 is turned off (energization to the solenoid 29 is turned off) to prohibit the starter 28 from being driven, and a reset signal is output to the idle stop control microcomputer 14 to turn off the idle stop control microcomputer 14. Reset.

  Further, when the engine control microcomputer 13 is reset, the output of the engine control microcomputer 13 becomes HiZ, so that the starter relay drive permission signal DA becomes H level (drive prohibition side of the starter relay 17) by the pull-up resistor 35 and idle. When the stop control microcomputer 14 is reset, the output of the idle stop control microcomputer 14 becomes HiZ, so that the starter relay drive signal DB becomes H level (drive stop side of the starter relay 17) by the pull-up resistor 36. ing.

  In the second embodiment described above, in the system that controls the starter 28 (solenoid 29 and starter motor 30) by controlling the first and second starter relays 31 and 32, an abnormality of the microcomputer 14 for idle stop control is detected. Then, the first starter relay 31 can be turned off (energization to the solenoid 29 can be turned off) to prohibit the starter 28 from being driven, and the same effect as in the first embodiment can be obtained.

  In the second embodiment, when the abnormality in the idle stop control microcomputer 14 is detected, the first starter relay 31 is turned off (energization to the solenoid 29 is turned off) to prohibit the starter 28 from being driven. However, the present invention is not limited to this, and when the abnormality of the microcomputer 14 for idle stop control is detected, the second starter relay 32 is turned off (energization to the starter motor 30 is turned off) to prohibit the starter 28 from being driven. You may do it.

  Next, Embodiment 3 of the present invention will be described with reference to FIG. However, substantially the same parts as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted or simplified. The parts different from those in the first and second embodiments are mainly described.

  In the third embodiment, as shown in FIG. 5, the transistor 37 and the first transistor 38 are arranged in series between the battery 11 and the first starter relay 31, and the battery 11 and the second starter relay 32. The transistor 37 and the second transistor 39 are arranged in series. Then, the transistor 37 is turned on / off by a starter relay drive permission signal DA from the engine control microcomputer 13. The first transistor 38 is turned on / off by the first starter relay drive signal DB1 from the idle stop control microcomputer 14, and the second starter relay drive signal DB2 from the idle stop control microcomputer 14 is turned on / off. The transistor 39 is turned on / off.

  In this case, when the starter relay drive permission signal DA from the engine control microcomputer 13 is at the L level (drive permission side of the starter relays 31 and 32), the transistor 37 is turned on, and the idle stop control microcomputer 14 When the first starter relay drive signal DB1 is at the L level (the drive side of the first starter relay 31), the first transistor 38 is turned on, and when both of these transistors 37 and 38 are turned on, the first transistor 38 is turned on. 1 starter relay 31 is turned on (energization to solenoid 29 is turned on).

  Further, when the starter relay drive permission signal DA from the engine control microcomputer 13 is at the L level (the drive permission side of the starter relays 31 and 32), the transistor 37 is turned on and the first stop signal from the idle stop control microcomputer 14 is turned on. The second transistor 39 is turned on when the second starter relay drive signal DB2 is at L level (the drive side of the second starter relay 32), and the second transistor 39 and 39 are both turned on. The starter relay 32 is turned on (energization to the starter motor 30 is turned on).

  In the third embodiment, the transistors 37 to 38 and the like function as an AND circuit, the starter relay drive permission signal DA from the engine control microcomputer 13 is at the L level, and the first and second from the idle stop control microcomputer 14. When both of the starter relay drive signals DB1 and DB2 are at the L level, both the first and second starter relays 31 and 32 are turned on (the energization to the solenoid 29 and the starter motor 30 are both turned on), and the starter 28 is driven normally.

  When the engine control microcomputer 13 detects an abnormality in the idle stop control microcomputer 14, the engine control microcomputer 13 switches the starter relay drive permission signal DA to the H level (drive prohibition side of the starter relays 31 and 32) to turn off the transistor 37. Thus, both the first and second starter relays 31 and 32 are turned off (the energization of both the solenoid 29 and the starter motor 30 is turned off) to inhibit the starter 28 from being driven and reset to the idle stop control microcomputer 14. A signal is output to reset the idle stop control microcomputer 14.

  When the engine control microcomputer 13 is reset, the output of the engine control microcomputer 13 becomes HiZ, so that the starter relay drive permission signal DA becomes H level (starter relay 17 drive prohibition side) by the pull-up resistor 40 and idle Since the output of the idle stop control microcomputer 14 becomes HiZ when the stop control microcomputer 14 is reset, the first and second starter relay drive signals DB1 and DB2 are set to the H level (starter relay 17 by the pull-up resistors 41 and 42). Drive stop side).

  In the third embodiment described above, in the system that controls the starter 28 (solenoid 29 and starter motor 30) by controlling the first and second starter relays 31 and 32, an abnormality of the microcomputer 14 for idle stop control is detected. In this case, the first and second starter relays 31 and 32 are both turned off (the solenoid 29 and the starter motor 30 are both turned off) to inhibit the starter 28 from being driven. The same effect as 1 can be obtained.

  In the third embodiment, since the two transistors 37 and 38 are arranged in series between the battery 11 and the first starter relay 31, one of the two transistors 37 and 38 is turned on. Even in this case, the first starter relay 31 can be turned off by turning off the other. Furthermore, since the two transistors 37 and 39 are arranged in series between the battery 11 and the second starter relay 32, even if one of the two transistors 37 and 39 is on-failed, the other is The second starter relay 32 can be turned off by turning it off.

  In a vehicle having an idle stop function, it is necessary to drive the starter even in a shift range other than the N range or the P range when restarting after an idle stop. In the case of a shift range other than the P range, the starter cannot be mechanically driven so that the starter drive circuit needs to be designed more safely. As in the third embodiment, two transistors are provided. It is effective to connect in series.

  Further, in the third embodiment, the transistor 37 driven by the starter relay drive permission signal from the engine control microcomputer 13 is provided with one common transistor for the two starter relays 31 and 32. The transistor 37 driven by the engine control microcomputer 13 can be shared (shared) with the two starter relays 31 and 32, so that an inexpensive configuration can be achieved.

  Next, Embodiment 4 of the present invention will be described with reference to FIG. However, substantially the same parts as those in the second embodiment are denoted by the same reference numerals, the description thereof is omitted or simplified, and different parts from the second embodiment will be mainly described.

  In the fourth embodiment, as shown in FIG. 6, the engine control microcomputer 13 includes a signal determination unit 44 that captures an output signal of the engine rotation sensor 43, and the engine rotation speed and Detects crank angle and cam angle. Other system configurations are the same as those of the second embodiment.

  Further, when the engine is stopped, the engine control microcomputer 13 detects the starter relay drive permission signal when the engine rotation speed detected based on the output signal of the engine rotation sensor 43 becomes a predetermined value (for example, 100 rpm) or less. By switching DA to L level and turning on the transistor 33, the first starter relay 31 (a starter relay for solenoid) is turned on. As a result, energization of the solenoid 29 is turned on to push out the pinion, and the pinion is engaged with the ring gear of the engine.

  When the engine is stopped, the engine rotation speed usually decreases rapidly or becomes unstable. Therefore, it is preferable to push out the pinion and mesh with the ring gear immediately before the engine stops. For this reason, as in the fourth embodiment, when the engine rotation speed becomes a predetermined value or less, the first starter relay 31 (starter relay for solenoid) is turned on to engage the pinion with the ring gear. For example, the pinion can be engaged with the ring gear immediately before the engine is stopped (before the next engine start). As a result, even when the idle stop control microcomputer 14 becomes abnormal immediately after the engine stops, the pinion can be maintained in a state in which the pinion is engaged with the ring gear. Can be restarted.

  Further, the engine control microcomputer 13 needs to accurately detect the crank angle and the cam angle and perform appropriate control on the fuel injection timing, the ignition timing, etc. for the purpose of reducing exhaust gas and the like. For this reason, a means (signal determination unit 44) for accurately detecting the crank angle and the cam angle is provided. For this reason, it is not necessary to newly provide a means for detecting an accurate crank angle and cam angle required for the engagement of the pinion.

  In each of the first to fourth embodiments, the engine control microcomputer functions as a monitoring IC that monitors whether there is an abnormality in the idle stop control microcomputer. However, the present invention is not limited to this. Separately, a monitoring IC for monitoring whether there is an abnormality in the idle stop control microcomputer may be provided.

  Next, Embodiment 5 of the present invention will be described with reference to FIG. However, substantially the same parts as those of the third embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified, and the parts different from the third embodiment will be mainly described.

  In the fifth embodiment, as shown in FIG. 7, the engine and idle stop control microcomputer 46 having both the engine control microcomputer function and the idle stop control microcomputer function, and the engine and idle stop control microcomputer 46 are combined. A monitoring IC 45 for monitoring the presence or absence of abnormality is provided. In the system configuration of the fifth embodiment, a monitoring IC 45 is provided in place of the engine control microcomputer 13 in the system configuration of the third embodiment (see FIG. 5), and the engine and idle are replaced by the idle stop control microcomputer 14. A stop control microcomputer 46 is provided. The engine / idle stop control microcomputer 46 includes a signal determination unit 44 that captures an output signal of the engine rotation sensor 43, and detects an engine rotation speed, a crank angle, and a cam angle based on the output signal of the engine rotation sensor 43. . Other system configurations are the same as those of the third embodiment.

Further, when the engine is stopped, the engine 46 and the idle stop control microcomputer 46 are configured to perform the first operation when the engine rotation speed detected based on the output signal of the engine rotation sensor 43 becomes a predetermined value (for example, 100 rpm) or less. The starter relay drive signal DB1 is switched to L level to turn on the first transistor 38, and the starter relay drive permission signal DA is switched to L level by the monitoring IC 45 to turn on the transistor 37, whereby the first starter relay 38 is turned on. The relay 31 (starter relay for solenoid) is turned on. As a result, energization of the solenoid 29 is turned on to push out the pinion, and the pinion is engaged with the ring gear of the engine.
In the fifth embodiment described above, substantially the same effect as in the fourth embodiment can be obtained.

  DESCRIPTION OF SYMBOLS 11 ... Battery (power supply), 13 ... Microcomputer for engine control (monitoring IC), 14 ... Microcomputer for idle stop control, 15 ... ECU, 17 ... Starter relay, 18 ... Starter, 19 ... Starter motor, 20 ... NAND circuit, DESCRIPTION OF SYMBOLS 21 ... Transistor, 22 ... Direct line (first signal line), 23 ... Communication line (second signal line), 28 ... Starter, 29 ... Solenoid, 30 ... Starter motor, 31, 32 ... Starter relay, 33 34 ... transistor 37-39 ... transistor 45 ... monitoring IC 46 ... microcomputer for engine and idle stop control

Claims (12)

Automatic engine stop start for performing idle stop control for automatically stopping the engine when a predetermined automatic stop condition is satisfied and driving the starter (18, 28) to restart the engine when the predetermined restart condition is satisfied In the control device,
A microcomputer for idle stop control (hereinafter referred to as “idle stop”) for controlling the starter (18, 28) by controlling a starter relay (17, 31, 32) for turning on / off the energization to the starter (18, 28). (14, 46) and whether there is an abnormality in the idle stop control microcomputer (14, 46) in two systems, the first signal line (22) and the second signal line (23). A monitoring IC (13, 45) for monitoring is mounted on one electronic control unit (15),
The monitoring IC (13, 45) turns off the starter relay (17, 31, 32) and detects the starter (18, 28) when it detects an abnormality in the idle stop control microcomputer (14, 46). The engine automatic stop / start control device is characterized by prohibiting the driving of the engine and resetting the microcomputer for idle stop control (14, 46). An engine control microcomputer for controlling the engine (hereinafter referred to as “engine control microcomputer”) (13) functions as the monitoring IC,
The engine automatic stop / start control device according to claim 1, wherein the idle stop control microcomputer (14) monitors whether the engine control microcomputer (13) is abnormal. As the starter relay, a plurality of starter relays (31, 32) operating independently to control the starter (28) are provided.
One starter relay (31) of the plurality of starter relays (31, 32) is driven by the engine control microcomputer (13), and the other starter relay (32) is the idle stop control microcomputer (14). The engine automatic stop / start control device according to claim 2, wherein the engine automatic stop / start control device is driven by the engine. As the starter relay, a solenoid starter relay (31) for turning on / off the energization of the solenoid (29) for pushing out the pinion of the starter (28), and a starter motor (30 for rotating the pinion) A starter relay (32) for the motor that turns on / off the energization of
The engine control microcomputer (hereinafter referred to as “engine control microcomputer”) (13, 46) for controlling the engine has means (44) for capturing the output signal of the engine rotation sensor (43), and the engine rotation When the engine rotational speed detected based on the output signal of the sensor (43) becomes a predetermined value or less, the solenoid starter relay (31) is turned on to engage the pinion with the ring gear of the engine. The engine automatic stop / start control device according to any one of claims 1 to 3. The idle stop control microcomputer (14) resets the engine control microcomputer (13) when detecting an abnormality of the engine control microcomputer (13),
The microcomputer for idling stop control (14) is also reset from when the engine control microcomputer (13) is reset until it is normally started, and when the engine control microcomputer (13) is reset, the engine control microcomputer (13) is reset. The starter relay drive permission signal from 13) becomes the drive prohibition side of the starter relay (17, 31, 32), and the starter from the idle stop control microcomputer (14) when the idle stop control microcomputer (14) is reset. The engine automatic stop / start control device according to any one of claims 2 to 4, wherein a relay drive signal is configured to be on a drive stop side of the starter relay (17, 31, 32).   The engine control microcomputer (13) prohibits the starter relay (17, 31, 32) from driving the starter relay drive permission signal from the engine control microcomputer (13) when the engine is not stopped. 6. The engine automatic stop / start control device according to claim 2, wherein the engine automatic stop / start control device is provided on the side. As the first signal line, a direct line (22) for transmitting a watchdog signal from the idle stop control microcomputer (14, 46) to the monitoring IC (13, 45) is provided.
As the second signal line, there is provided a communication line (23) for transmitting and receiving information dedicated for monitoring between the idle stop control microcomputer (14, 46) and the monitoring IC (13, 45). The engine automatic stop / start control device according to any one of claims 1 to 6.   The communication line (23) is a communication line for connecting the idle stop control microcomputer (14, 46) and the monitoring IC (13, 45) on a one-to-one basis without using a transceiver IC. The engine automatic stop / start control device according to claim 7. The starter relay drive permission signal from the monitoring IC (13, 45) is on the drive permission side of the starter relay (17, 31, 32) and the starter relay drive signal from the idle stop control microcomputer (14, 46). Includes an AND circuit (20, 21, 33, 34, 37, 38, 39) for turning on the starter relay (17, 31, 32) when the starter relay (17, 31, 32) is on the drive side. ,
When the monitoring IC (13, 45) detects an abnormality in the idle stop control microcomputer (14, 46), the monitoring IC (13, 45) receives a starter relay drive permission signal from the monitoring IC (13, 45). The engine automatic stop / start control device according to any one of claims 1 to 8, wherein the starter relay (17, 31, 32) is turned off by setting the drive prohibiting side to 17, 17, 32).   In the AND circuit, a plurality of transistors (37, 38, 39) are arranged in series between a power source (11) and the starter relay (31, 32), and one transistor (37) is the monitoring IC. The starter relay drive permission signal from (13, 45) is driven, and the other transistor (38, 39) is driven by the starter relay drive signal from the idle stop control microcomputer (14, 46). The engine automatic stop / start control device according to claim 9, wherein the engine automatic stop / start control device is configured. As the starter relay, a plurality of starter relays (31, 32) operating independently to control the starter (28) are provided.
The transistor driven by the starter relay drive permission signal from the monitoring IC (13, 45) is provided with one common transistor (37) for the plurality of starter relays (31, 32),
The transistor driven by the starter relay drive signal from the idle stop control microcomputer (14, 46) is one transistor (38, 38) for each starter relay with respect to the plurality of starter relays (31, 32). The engine automatic stop / start control device according to claim 10, wherein 39) is provided.   The engine automatic according to any one of claims 1 to 11, wherein the monitoring IC (13, 45) has a function of monitoring a drive terminal of the starter relay (17, 31, 32). Stop / start control device.

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