JP2012180794A - Engine start control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adequately cope with the cause of the failure in the case an engine cannot be started.SOLUTION: An ECU 40 executes abnormality diagnosis based on whether or not abnormality determining conditions predetermined for each diagnosis object are established for a diagnosis target being a plurality of abnormality contents occurring after start of movement of a pinion 14 and rotation of a motor 11 until finish of cranking of an engine 20. Moreover, in the case any of abnormality determining conditions out of the plurality of the abnormality contents is established and it is determined that abnormality has occurred, the ECU 40 commands stoppage of drive of a starter 10. In this case, depending on the abnormality content diagnosed as abnormal by the abnormality diagnosis, time from the establishment of the abnormality determining condition to the command of the stoppage of drive of the starter 10 is varied.

Description

  The present invention relates to an engine start control device.

  In general, the engine is started by applying initial rotation to the output shaft (crankshaft) of the engine by a starter. Specifically, first, a pinion provided on the starter is pushed out in the axial direction of the pinion rotation shaft, thereby meshing the pinion with a ring gear connected to the crankshaft. Thereafter, the pinion is rotated by energizing the motor of the starter, and the ring gear is rotated by the rotational force. Thereby, engine cranking is performed. Further, after the engine is started, the pinion is released from the ring gear by releasing the pinion and the cranking is finished.

  When the starter is driven at the time of starting the engine, it may be inconvenient that the engine cannot be started if the pinion and the ring gear do not mesh with each other. Therefore, conventionally, a technique for avoiding a meshing failure between the pinion and the ring gear has been proposed (see, for example, Patent Document 1). In Patent Document 1, a starter block relay that can cut off the energization to the starter even when the starter switch is on is provided in the start circuit, and when the engine is restarted, the engine rotational speed that can be recognized by the engine ECU becomes zero. The starter block relay is kept off until a predetermined delay time elapses. As a result, it is possible to avoid the possibility that the pinion jumps into the ring gear that is not stationary during the decrease in the engine rotation speed due to the engine stop, thereby causing a meshing failure.

JP 2009-191653 A

  However, in Patent Document 1, since the engine is not restarted until the rotation of the engine is completely stopped, when the driver requests to start while the engine speed is decreasing, the start request is quickly satisfied. You may not be able to. On the other hand, when the pinion is pushed out to the rotating ring gear, it is considered that there is a higher possibility of a meshing failure than when the ring gear is stationary, and it is necessary to take measures when a meshing failure occurs.

  Further, there are various reasons why the engine cannot be started, such as those caused by an engine-side event in addition to the above-described poor meshing. Furthermore, depending on the cause, for example, inconvenience may occur due to driving of the starter, and conversely, if starter driving is continued, normal cranking may be possible. Therefore, if the starter driving is continued in the former, the influence due to the inconvenience is increased, and if the starter driving is immediately stopped in the latter, the time required for starting the engine may be increased.

  The present invention has been made in view of the above problems, and when the engine cannot be started, it is possible to appropriately deal with the cause of the engine being unable to start, and thus the engine start control capable of appropriately executing the engine start control. The main purpose is to provide a device.

  The present invention employs the following means in order to solve the above problems.

  When starting the engine, the starter pinion is moved toward the ring gear connected to the engine output shaft to cause the pinion and the ring gear to mesh with each other, and the motor of the starter in the meshed state The engine start control device is configured to crank the engine by rotation of the engine, and then stop driving by stopping the starter. In the invention according to claim 1, a plurality of abnormal contents occurring after the start of the movement of the pinion and the rotation of the motor and before the end of the cranking are set as diagnosis targets, and each diagnosis target is detected. An abnormality diagnosis means for performing an abnormality diagnosis based on the success or failure of the abnormality determination condition set in the above, and when the abnormality diagnosis condition of any of the plurality of abnormality contents is satisfied by the abnormality diagnosis means and the abnormality is diagnosed, Starter control means for commanding stop of driving of the starter, wherein the starter control means is configured to detect the abnormality of the starter after the abnormality determination condition is satisfied according to the abnormality content diagnosed as abnormal by the abnormality diagnosis means. It is characterized in that the time until the drive stop command is made variable.

  In short, there are various reasons why the engine cannot be started (abnormal content). Depending on the abnormal content, there may be a high urgency to stop the starter drive. Conversely, there is a high possibility that the engine can be started. It may be desirable to continue as long as possible. In view of that point, in the above configuration, when the engine cannot be started, the abnormality content is specified based on a predetermined abnormality determination condition for each abnormality content, and the abnormality determination condition is determined according to the specified abnormality content. The time until the start of driving of the starter is commanded after is established. In this case, the starter can be stopped at an appropriate timing according to the cause that the engine cannot be started, so that the engine start control can be optimized.

  According to a second aspect of the present invention, the diagnosis target by the abnormality diagnosing unit includes a meshing failure between the pinion and the ring gear after the start of movement of the pinion, and the starter control unit is an abnormality for determining the meshing failure. When the determination condition is satisfied and it is diagnosed that there is an abnormality, abnormality occurrence information indicating that an abnormality has occurred is stored, and the start of the starter is instructed immediately after the abnormality determination condition is satisfied.

  When the meshing failure occurs, the engine cannot be started even if the starter driving is continued as it is, and the pinion and the ring gear may be worn by continuing the starter driving. That is, it is considered highly urgent to stop the starter drive when a meshing failure occurs. In view of this point, wear of the pinion and the ring gear can be suppressed by adopting the above configuration.

  More specifically, the determination method for the meshing failure is, as in the invention described in claim 3, as an abnormality determination condition for determining the meshing failure, the rotational load of the motor after the rotation of the motor is And the passage speed of the tooth portion of the pinion is preferably higher than the passage speed of the tooth portion of the ring gear.

  According to a fourth aspect of the present invention, the diagnosis target of the abnormality diagnosing unit includes continuous cranking that is abnormal in which a predetermined time elapses while the cranking of the engine by the starter continues, and the starter control unit includes When an abnormality determination condition for determining continuous cranking is established and an abnormality is diagnosed, abnormality occurrence information indicating that an abnormality has occurred is stored, and a first delay time has elapsed after the abnormality determination condition is satisfied. Later, the stop of the starter is commanded.

  According to a fifth aspect of the present invention, the diagnosis target by the abnormality diagnosing means includes a non-rotation abnormality that is an abnormality that does not increase the engine rotation speed when the meshing occurs, and the starter control means includes the non-rotation abnormality When an abnormality determination condition for determining a rotation abnormality is established and it is diagnosed that there is an abnormality, the abnormality occurrence information indicating that an abnormality has occurred is stored, and after the second delay time has elapsed after the establishment of the abnormality determination condition Commands the starter to stop driving.

  If the reason why the engine cannot be started is due to continuous cranking or non-rotation abnormality, the pinion and the ring gear are engaged.Therefore, it is possible that the engine can be started by continuing the cranking as it is. It is done. Also, in these cases, unlike the case of poor meshing, there is little possibility that inconveniences such as pinion and ring gear wear due to continued starter drive occur. Therefore, as in the configurations of claims 4 and 5 described above, the engine can be started early by providing a grace period from when the abnormal content is specified until the starter drive is forcibly stopped.

1 is an overall schematic configuration diagram of an engine control system. The figure which shows the determination conditions of a meshing defect. The figure which shows transition of the battery voltage after a pinion extrusion and a motor drive start. The time chart which shows the specific aspect when a meshing defect arises. The figure which shows the determination conditions of continuous cranking. The time chart which shows the specific aspect when continuous cranking arises. The figure which shows the determination conditions of a continuous lock. The time chart which shows the specific aspect when a continuous lock arises. The flowchart which shows the process sequence of an abnormality diagnosis process.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. This embodiment is embodied in an engine start control device of an engine control system. In the control system, fuel injection amount control, ignition timing control, idle stop control, and the like are performed with an electronic control unit (hereinafter referred to as ECU) as a center. FIG. 1 is a block diagram showing the overall outline of this control system.

  In FIG. 1, an engine 20 is, for example, a four-cylinder engine, and includes a throttle valve 21 as an air amount adjusting unit that adjusts an intake air amount into the cylinder, an injector 22 as a fuel injection unit that injects and supplies fuel, and a cylinder. An igniter (not shown) or the like is provided as ignition means for generating ignition sparks in a spark plug 23 provided for each. The engine 20 may be an intake port injection type in which the injector 22 is provided in the vicinity of the intake port, or may be a direct injection type provided in a cylinder head or the like of each cylinder.

  The starter 10 is provided with a motor 11, and the motor 11 is rotationally driven by power supply from the battery 12. Further, a pinion 14 is provided on the rotating shaft 13 of the motor 11, and the pinion 14 is rotated by the rotation of the rotating shaft 13. The pinion 14 is integrated with a one-way clutch 15 that intermittently transmits power between the rotary shaft 13 and the pinion 14.

  The starter 10 is provided with an actuator SL1 including a coil 18 and a plunger 19, and the pinion 14 is reciprocated in the axial direction of the rotary shaft 13 by switching between energization / non-energization of the coil 18. ing.

  Specifically, when the coil 18 is not energized, the pinion 14 is disposed in a non-contact state with respect to the ring gear 25 connected to the output shaft (crankshaft) 24 of the engine 20. When the coil 12 is energized from the battery 12 in this non-contact state, the plunger 19 moves in the axial direction, the lever 16 is actuated, and the pinion 14 is pushed out toward the ring gear 25. As a result, the pinion 14 moves to the contact position with the ring gear 25. Further, with the movement of the pinion 14, the teeth of the pinion 14 and the teeth of the ring gear 25 are engaged, and power can be transmitted from the pinion 14 to the ring gear 25. When the drive of the motor 11 is started in this meshing state, power transmission from the pinion 14 to the ring gear 25 is performed.

  On the other hand, when the energization of the coil 18 is interrupted while the pinion 14 and the ring gear 25 are engaged, the pinion 14 moves in a direction opposite to the direction toward the ring gear 25 by the biasing force of a spring (not shown). As a result, the meshing between the pinion 14 and the ring gear 25 is released, and both return to a non-contact state.

  An IG switch 26 is provided between the starter 10 and the battery 12, and energization from the battery 12 to the starter 10 is possible by turning on the IG switch 26 by a driver. Further, an SL1 drive relay 27 that switches between energization / non-energization of the actuator SL1 based on a control signal is provided between the coil 18 and the battery 12. Further, between the motor 11 and the battery 12, a motor switch SL2 connected to an electromagnetic element of the motor 11 and switching energization / non-energization by opening / closing a contact, and energization / non-energization of the motor switch SL2 based on a control signal are performed. A switching SL2 drive relay 28 is provided.

  In addition, in this system, a crank angle sensor 31 that outputs a rectangular detection signal (crank angle signal) at every predetermined crank angle of the engine 20 (for example, at a cycle of 10 ° CA), or the temperature of engine coolant is detected. Various sensors such as a coolant temperature sensor 32, an SL1 voltage sensor 33 for detecting the terminal voltage of the actuator SL1, an SL2 voltage sensor 34 for detecting the terminal voltage of the motor switch SL2, and a battery voltage sensor 35 for detecting the voltage of the battery 12 are provided. ing.

  The ECU 40 is an electronic control device including a known microcomputer or the like, and inputs detection results of various sensors provided in the system, and based on this, fuel injection amount control, ignition timing control, idle stop control Various engine controls such as the above, and drive control of the starter 10 are performed.

  The idle stop control performed in the above system configuration will be described in detail. In the idle stop control, when a predetermined automatic stop condition is satisfied during the idling operation of the engine 20, the engine 20 is automatically stopped by stopping fuel injection and ignition and stopping the combustion of the engine 20. When a predetermined restart condition is satisfied after the automatic stop condition is satisfied, the fuel injection and ignition are resumed and the engine 20 is restarted. As the automatic stop condition, for example, the accelerator operation amount has become zero (idle state), the brake pedal has been depressed, the vehicle speed has decreased to a predetermined value or less, etc. Is included. In addition, the restart condition includes, for example, that an accelerator depression operation has been performed, a brake operation amount has become zero, and the like.

  Next, drive control of the starter 10 will be described. In the present embodiment, the ECU 40 includes an output port P1 that outputs an on / off signal of the SL1 drive relay 27, and an output port P2 that outputs an on / off signal of the SL2 drive relay 28. In the ECU 40, the energization states of the motor 11 and the coil 18 can be individually switched by control signals from these output ports P1 and P2.

  For example, let us consider a case where the restart condition is satisfied while the engine speed is decreasing after the combustion of the engine 20 is stopped as the automatic stop condition is satisfied. As one aspect in this case, the ECU 40 first pushes the pinion 14 toward the ring gear 25 by turning on the SL1 drive relay 27 on condition that the engine rotational speed is equal to or lower than a predetermined low rotational speed. . After that, when the pinion 14 and the ring gear 25 come into contact with each other or when the meshing of both occurs, the SL2 drive relay 28 is turned on to drive the motor 11 and rotate the pinion 14. In this aspect, since the engine 20 is restarted without waiting for the rotation of the crankshaft 24 to stop, the engine 20 can be started as soon as possible after an engine restart request is made.

  Here, when the restart condition is satisfied, after the push-out of the pinion 14 and the start of the motor rotation, for example, a poor meshing between the pinion 14 and the ring gear 25 occurs or the combustion of the engine 20 is not performed, the starter It is conceivable that the engine 20 cannot be started even if driving is continued. Further, in this case, it is conceivable that the energization time becomes long, so that the rotational load of the motor 11 becomes excessive or the consumption of the battery 12 progresses.

  Therefore, in this embodiment, when the engine 20 cannot be started even after a predetermined time has elapsed since the starter drive, the drive of the starter 10 is temporarily stopped. Specifically, the ECU 40 measures the elapsed time from the start of energization of the coil 18 and the elapsed time from the start of energization of the motor 11 when driving the starter. When at least one of the conditions that the energization time of the coil 18 exceeds the determination time Time1 and the energization time of the motor 11 exceeds the determination time Time2, the energization of the coil 18 and the motor 11 is established. Cut off. In addition, after the starter 10 is stopped, the coil 18 and the motor 11 are energized again to restart the engine (retry).

  Note that when the drive of the starter 10 is stopped, a warning that prompts engine start (key start) is given to the driver, and the engine is restarted based on the driver's key operation that recognizes this. .

  By the way, there are various reasons why the engine 20 cannot be started. Depending on these causes, there is a high urgency to forcibly stop the starter 10 drive. On the contrary, there is a high possibility that the engine 20 can be started. It may be desirable to continue for a long time.

  Therefore, in this embodiment, when the engine start by the starter 10 is not properly performed, an abnormality diagnosis is performed to identify the abnormality content, and a countermeasure appropriate to each abnormality content is performed according to the identified abnormality content. To do. Specifically, when the engine is started, each abnormality content is specified for a plurality of abnormality contents that may occur after the start of pushing out the pinion 14 and the rotation of the motor 11 until the cranking is finished. An abnormality determination condition for this is determined in advance for each abnormality content. Then, the ECU 40 identifies the abnormality content when the engine 20 cannot be started based on the success or failure of the abnormality determination condition, and stops driving the starter 10 after the abnormality determination condition is satisfied according to the specified abnormality content. The time to do is variable.

  Hereinafter, the abnormality content that may occur when starting the engine and the abnormality determination conditions for specifying each abnormality content will be described.

(1) Improper meshing After the pinion 14 is pushed out, if the meshing failure between the pinion 14 and the ring gear 25 occurs, the pinion 14 is idle while the tooth end surface of the pinion 14 is in contact with the tooth end surface of the ring gear 25. May be. In this case, not only can the engine 20 be started even if the starter drive is continued, but wear of the pinion 14 and the ring gear 25 may be promoted if the starter drive is continued. Therefore, in the present embodiment, the meshing failure is included as the diagnosis target of the abnormality diagnosis, and the driving of the starter 10 is stopped when the meshing failure is detected. In particular, when a mesh failure occurs, it is unlikely that the engine 20 can be started even if the starter drive is continued, and wear of the pinion 14 or the like may be promoted by continuing the starter drive. Immediately after the occurrence of this is identified, the drive of the starter 10 is immediately stopped.

Specifically, as shown in FIG.
(A) The starter drive command is made (b) The two conditions that the voltage is applied to the starter terminal are satisfied, and the abnormality determination condition for specifying the meshing failure is as follows:
(C1) After the rotation of the motor 11 is started, the rotational load of the motor 11 is in a no-load or low-load driving state. (C2) The passage speed of the tooth portion of the pinion 14 is higher than the passage speed of the tooth portion of the ring gear 25. It is determined that a meshing failure has occurred when all the conditions including the faster one are satisfied.

  Here, regarding the condition (a), when the ON signal is output to the SL1 drive relay 27 and the SL2 drive relay 28, it is determined that the condition is satisfied. The condition (b) is determined based on the detection values of the SL1 voltage sensor 33 and the SL2 voltage sensor 34. For example, when the sensor detection value is larger than the determination value, it is determined that a voltage is applied to the starter terminal. To do.

  The condition (c1) is determined based on the detection value of the battery voltage sensor 35, for example. Specifically, as shown in FIG. 3, after the SL2 drive relay 28 is turned on, a transition of how much the voltage fluctuates with respect to the battery voltage Vo (for example, 14V) at the time of off is detected as a voltage fluctuation width ΔVB. To do. When the detected voltage fluctuation width ΔVB is larger than the first determination value V1 (in the case of the solid line in FIG. 3), it is determined that the rotational load of the motor 11 is equivalent to that at the time of cranking. On the other hand, when the voltage fluctuation width ΔVB is equal to or smaller than the first determination value V1 (in the case of the one-dot chain line in FIG. 3), the motor rotation load after the rotation of the motor 11 is smaller than that during cranking, that is, the motor 11 is unloaded or It is determined that the load is low.

  The determination of the condition (c1) is not limited to the method based on the voltage fluctuation range of the battery 12, but for example, the motor torque is detected by a torque sensor or calculated based on the engine rotation speed, and the detected value or the calculated value is calculated. May be based on.

  Regarding the condition (c2), in the present embodiment, whether or not the condition is satisfied is determined by detecting whether or not the engine rotation speed (ring gear rotation speed) has become zero. Specifically, after the start of the starter 10, when the crank angle signal is not updated and the non-update time continues for a predetermined time T1 or longer, the NE signal update determination flag f1 is turned on. Whether the condition (c2) is satisfied is determined based on the NE signal update determination flag f1.

  FIG. 4 is a time chart showing a specific mode when a meshing failure occurs. In the figure, (a) shows the transition of the pinion drive command (ON command of the SL1 drive relay 27), (b) shows the change of the motor drive command (ON command of the SL2 drive relay 28), and (c) shows the SL1 voltage sensor 33. Transition of detection value, (d) transition of detection value of SL2 voltage sensor 34, (e) transition of voltage fluctuation width ΔVB of battery 12, (f) transition of crank angle signal, (g) NE signal update Transition of the determination flag f1, (h) shows transition of the meshing failure occurrence flag fa.

  Regarding the voltage fluctuation range ΔVB in (e), a low level detection signal is output when the fluctuation range of the battery voltage after the SL2 drive relay 28 is turned on is larger than the first determination value V1, and the first determination value is output. A high level detection signal is output when V1 or less. In FIG. 4, it is assumed that the restart condition is satisfied during the descent of the engine rotation after the combustion of the engine 20 is stopped as the automatic stop condition is satisfied.

  In FIG. 4, as the restart condition is established, the pinion drive command is turned on at timing t11, and the motor drive command is turned on at timing t12, whereby a voltage is applied to the starter terminal. Thereby, pushing out of the pinion 14 to the ring gear 25 and driving of the motor 11 are started. At this time, when the engagement of the pinion 14 and the ring gear 25 occurs, and power is transmitted from the pinion 14 to the ring gear 25, the voltage fluctuation width ΔVB of the battery 12 is first determined as shown by a one-dot chain line in FIG. The state larger than the value V1 continues.

  On the other hand, when no meshing occurs, power transmission from the pinion 14 to the ring gear 25 is not performed, and the voltage fluctuation range ΔVB of the battery 12 is equal to or less than the first determination value V1 as shown by a solid line in FIG. Will continue. Further, the engine rotation speed gradually approaches 0, and as shown in (g), after the pulse width of the crank angle signal gradually increases, the pulse is not updated. If the pulse update is not continuously performed for the predetermined time T1, the NE signal update determination flag f1 is turned on at timing t13.

  At this timing t13, it is assumed that all the conditions for specifying the mesh failure are satisfied, the mesh failure occurrence flag fa is turned on, and the flag information is stored in the nonvolatile memory as abnormality occurrence information. Also, as shown in FIGS. 4A and 4B, immediately after the determination timing t13, the drive stop of the pinion 14 and the drive stop of the motor 11 are instructed. Thereby, the drive of the starter 10 is stopped immediately.

(2) Continuous cranking After the starter drive is started, the pinion 14 and the ring gear 25 are engaged, but continuous cranking may occur as an abnormality in which the cranking of the engine 20 by the starter 10 continues. The cause of the continuous cranking is, for example, a condition in which the combustion of the engine 20 is not resumed, a battery voltage is insufficient, or an excessive load is required for overcoming the piston top dead center (for example, a temperature condition) ). Also in this case, the starter drive is forcibly stopped, and after that stop, the starter 10 is energized again to restart the engine.

  However, in the case of continuous cranking, unlike the case of poor meshing, the urgency to stop the starter drive immediately is not so high. Further, in this case, since the engagement between the pinion 14 and the ring gear 25 is generated, it is considered that the engine 20 may be started by continuing the starter drive for a while.

  Therefore, in the present embodiment, when the abnormality content that cannot be started is due to continuous cranking, the abnormality occurrence information is stored at the time when the abnormality content is specified, and after the abnormality content is specified, a predetermined delay time is stored. The starter 10 is instructed to stop driving after Tdy1 has elapsed. This delay time Tdy1 is set to be longer than the time required to command the stop of driving of the starter 10 after the abnormality content is specified (after turning on the meshing failure occurrence flag fa) when the meshing failure occurs. Yes, in this embodiment, it is several seconds (for example, 2 to 3 seconds).

  Next, the continuous cranking determination method will be specifically described with reference to FIG.

For continuous cranking, as shown in FIG.
(A) The starter drive command is made (b) Two conditions of voltage being applied to the starter terminal are satisfied, and as an abnormality determination condition for specifying continuous cranking,
(D1) A predetermined time has elapsed from the starter drive command (d2) The engine 20 is rotating (the engine speed is greater than 0)
(D3) It is determined that the abnormality has occurred when all the conditions including that the combustion of the engine 20 is not resumed are satisfied.

  The condition (d3) is performed based on the engine speed detected by the crank angle sensor 31 in this embodiment. Specifically, it is determined that the condition (d3) is satisfied when the engine rotation speed has not reached the ignition rotation speed (for example, 500 to 600 rpm) indicating that the engine 20 has been ignited. To do.

  FIG. 6 is a time chart showing a specific mode when continuous cranking occurs. In the figure, (a) is the transition of the pinion drive command, (b) is the transition of the motor drive command, (c) is the transition of the detection value of the SL1 voltage sensor 33, and (d) is the transition of the detection value of the SL2 voltage sensor 34. (E) shows the transition of the crank angle signal, (f) shows the transition of the NE signal update determination flag f1, (g) shows the transition of the ignition determination flag f2, and (h) shows the transition of the continuous cranking occurrence flag fb. In FIG. 6, it is assumed that the restart condition is satisfied during the engine rotation descent after the combustion of the engine 20 is stopped along with the establishment of the automatic stop condition.

  In FIG. 6, when the restart condition is satisfied, the pinion drive command is turned on at timing t21, and the motor drive command is turned on at timing t22, whereby a voltage is applied to the starter terminal. As a result, the pinion 14 is pushed out toward the ring gear 25 and the drive of the motor 11 is started.

  In this case, if the engagement of the pinion 14 and the ring gear 25 occurs and the combustion of the engine 20 is resumed, the engine rotation speed reaches the ignition rotation speed, and an ignition determination flag as shown by a one-dot chain line in (g). f2 is turned on. On the other hand, when the engine rotation speed does not reach the ignition rotation speed after the pinion 14 and the ring gear 25 are engaged, a rotational force is applied from the starter 10 to the crankshaft 24 as shown in (e) and (g). As a result, the crank angle signal is sequentially updated, but the ignition determination flag f2 remains off.

  When a predetermined time T2 continues from the start of rotation of the motor 11, the continuous cranking generation flag fb is turned on at timing t23 on the assumption that all conditions for specifying continuous cranking are satisfied, and the flag information is It is stored in the nonvolatile memory as abnormality occurrence information. Further, as shown in (a) and (b), the pinion drive command and the motor drive command are turned off at the timing t24 after the delay time Tdy1 has elapsed from the timing t23, and the drive of the starter 10 is stopped.

  In this embodiment, even when the engine 20 is restarted before the delay time Tdy1 elapses from the timing t23, the abnormality occurrence information related to continuous cranking is stored in the nonvolatile memory. Therefore, the occurrence history of the abnormality can be grasped by referring to the information in the nonvolatile memory.

(3) Non-rotation abnormality (continuous lock)
After the starter driving is started, the pinion 14 and the ring gear 25 are engaged with each other, but a non-rotation abnormality (continuous lock), which is an abnormality that does not increase the engine rotation speed, may occur. The cause of this continuous lock is, for example, that the output shaft of the engine 20 is in a non-rotating state for some reason, that power is transmitted from the engine side to the starter side when the engine is restarted on an uphill road. It can be considered. In this case, the starter drive is forcibly stopped, and after that stop, the starter 10 is energized again to restart the engine.

  In the case of continuous lock, it is considered that the urgency to stop the starter drive immediately is not so high as in the case of continuous cranking. Further, if the starter drive is continued when the continuous lock is generated, the engine 20 may be started because the meshing occurs. Therefore, if the abnormal content that the engine cannot be started is continuous lock, the abnormality occurrence information is stored at the time when the abnormal content is specified, and after the predetermined delay time Tdy2 has elapsed since the abnormal content was specified. 10 drive stop is commanded.

  Note that the delay time Tdy2 is set to be longer than the time required to stop driving the starter 10 after the occurrence of an abnormality (after turning on the engagement failure occurrence flag fa) when an engagement failure occurs. In this embodiment, it is set to several seconds (for example, 2 to 3 seconds). This delay time Tdy2 may be the same as or different from the delay time Tdy1 in the case of continuous cranking.

  Next, the continuous lock detection method will be described in detail with reference to FIG.

For continuous lock, as shown in FIG.
(A) The starter drive command is made (b) Two conditions that a voltage is applied to the starter terminal are satisfied, and as an abnormality determination condition for specifying continuous lock,
(E1) The motor 11 is in a high-load drive state (e2) The engine 20 is not rotating (the engine rotation speed is substantially zero).
When all the conditions including are satisfied, it is determined that the continuous lock has occurred.

  Of the abnormality determination conditions, the condition (e1) is determined based on, for example, the detection value of the battery voltage sensor. Specifically, as shown in FIG. 3, the determination is made based on the voltage fluctuation range ΔVB after the SL2 drive relay 28 is turned on. At this time, when the voltage fluctuation width ΔVB is smaller than the second determination value V2 (> V1) (in the case of the solid line in FIG. 3), the motor 11 is in a rotational load state equivalent to the meshed state of the pinion 14 and the ring gear 25. It is determined that On the other hand, when the voltage fluctuation width ΔVB is equal to or larger than the second determination value V2 (in the case of the two-dot chain line in FIG. 3), it is determined that the motor 11 is in a high load state. Note that the condition (e1) may also be determined based on the detected value or the calculated value, for example, by detecting the motor torque by a torque sensor or calculating it based on the engine rotational speed.

  FIG. 8 is a time chart showing a specific mode when continuous lock occurs. In the figure, (a) is the transition of the pinion drive command, (b) is the transition of the motor drive command, (c) is the transition of the detection value of the SL1 voltage sensor 33, and (d) is the transition of the detection value of the SL2 voltage sensor 34. , (E) shows the transition of the voltage fluctuation width ΔVB of the battery 12, (f) shows the transition of the crank angle signal, (g) shows the transition of the NE signal update determination flag f1, and (h) shows the transition of the continuous lock occurrence flag fc. Show.

  As for the voltage fluctuation range ΔVB in (e), a low-level detection signal is output when the fluctuation range of the battery voltage after the SL2 drive relay 28 is turned on is smaller than the second determination value V2, and the second determination value is output. A high level detection signal is output when V2 or higher.

  In FIG. 8, when the restart condition is satisfied, the pinion drive command is turned on at timing t31, and the motor drive command is turned on at timing t32, whereby a voltage is applied to the starter terminal. As a result, the pinion 14 is pushed out toward the ring gear 25 and the drive of the motor 11 is started.

  In this case, if the engagement of the pinion 14 and the ring gear 25 occurs and the combustion of the engine 20 is resumed, the engine rotation speed is increased by the combustion energy, and the crank angle signal is sequentially updated. On the other hand, when the continuous lock has occurred, as shown in (e) and (f), a state in which the motor 11 is in a high load state and the crank angle signal is not updated is detected. In this case, the NE signal update determination flag f1 is turned on at a timing t33 after a predetermined time T3 has elapsed from the start of driving of the starter 10, and the time T3 is the same as or different from the time T1 at the time of poor meshing. Also good.

  At this timing t33, the continuous lock occurrence flag fc is turned on assuming that all conditions for specifying the continuous lock are satisfied. Further, at a timing t34 after a predetermined delay time Tdy2 has elapsed from the timing t33, the pinion drive command and the motor drive command are turned off, and the drive of the starter 10 is stopped.

  As in the case of continuous cranking, when the continuous lock is generated, even when the engine 20 is restarted before the delay time Tdy2 elapses from the timing t33, the abnormality occurrence information regarding the continuous lock is stored in the nonvolatile memory. Remembered. Therefore, the occurrence history of the abnormality can be grasped by referring to the information in the nonvolatile memory.

  Next, the abnormality diagnosis process at the time of engine start according to the present embodiment will be described with reference to FIG. This process is executed at predetermined intervals by the microcomputer of the ECU 40.

  In FIG. 9, in step S11, it is determined whether or not the engine restart condition is satisfied after the engine automatic stop condition is satisfied. When step S11 is YES, it progresses to step S12, and it is determined whether SL1 drive relay 27 is an ON state and SL2 drive relay 28 is an ON state. The on / off control of the SL1 drive relay 27 and the SL2 drive relay 28 is executed by a separate routine (not shown).

  When step S12 is YES, it progresses to step S13 and acquires the voltage fluctuation range (DELTA) VB of the battery 12 as information regarding a motor rotational load. In step S14, the NE signal update determination flag f1 and the ignition determination flag f2 are acquired as information on the crank angle signal.

  In step S15, (c1) the motor 11 is in a no-load or low-load drive state, and (c2) the passage speed of the tooth portion of the pinion 14 is faster than the passage speed of the tooth portion of the ring gear 25. The success or failure of the two conditions is determined. Here, when the voltage fluctuation width ΔVB of the battery 12 is equal to or smaller than the first determination value V1 and the NE signal update determination flag f1 is on, an affirmative determination is made, and the process proceeds to step S16.

  In step S16, the engagement failure occurrence flag fa is turned on, and the flag information is stored in the nonvolatile memory as abnormality occurrence information. In step S17, immediately after the engagement failure occurrence flag fa is turned on, an off command is issued to the SL1 drive relay 27 and an off command is issued to the SL2 drive relay 28. Thereby, the drive of the starter 10 is stopped immediately. Thereafter, the meshing failure occurrence flag fa is switched off.

  In step S18, three conditions are (d1) that a predetermined time T2 has elapsed from the starter drive command, (d2) that the engine 20 is rotating, and (d3) that the combustion of the engine 20 is not restarted. Determine success or failure. Here, an affirmative determination is made when time T2 has elapsed from the ON of the SL2 drive relay, the NE signal update determination flag f1 is off, and the ignition determination flag f2 is off, and the process proceeds to step S19.

  In step S18, in addition to the conditions (d1) to (d3), it may be determined whether or not (d4) the condition that the motor rotational load is in a predetermined normal range is satisfied. In this case, when the voltage fluctuation range ΔVB is greater than the first determination value V1 and less than the second determination value V2, it is determined that the condition is satisfied, and the process proceeds to step S19.

  In step S19, the continuous cranking occurrence flag fb is turned on, and the flag information is stored in the nonvolatile memory as abnormality occurrence information. In step S20, it is determined whether or not a predetermined delay time Tdy1 has elapsed since the continuous cranking occurrence flag fb was turned on. When the delay time Tdy1 has elapsed, an instruction to turn off the SL1 drive relay 27 is given. An off command is issued to the SL2 drive relay 28. Thereafter, the continuous cranking occurrence flag fb is switched off.

  In step S21, whether or not two conditions are satisfied is determined: (e1) the motor 11 is in a high-load drive state, and (e2) the engine 20 is not rotating. Here, an affirmative determination is made when the voltage fluctuation range ΔVB is equal to or larger than the second determination value V2 and the NE signal update determination flag f1 is on, and the process proceeds to step S22.

  In step S22, the continuous lock occurrence flag fc is turned on, and the flag information is stored in the nonvolatile memory as abnormality occurrence information. In step S23, it is determined whether or not a predetermined delay time Tdy2 has elapsed since the continuous lock occurrence flag fc was turned on. When the delay time Tdy2 has elapsed, the SL1 drive relay 27 is instructed to turn off, and SL2 An off command is given to the drive relay 28. Thereafter, the continuous lock occurrence flag fc is switched off.

  If a negative determination is made in steps S15, S18, and S21, the process proceeds to step S24. In step S24, it is determined whether the elapsed time since the SL1 drive relay 27 is turned on exceeds the determination time Time1, or whether the elapsed time after the SL2 drive relay 28 is turned on exceeds the determination time Time2. To do. If step S24 is YES, the process proceeds to step S17, where an off command is issued to the SL1 drive relay 27 and an off command is issued to the SL2 drive relay 28.

  According to the embodiment described in detail above, the following excellent effects can be obtained.

  When the engine 20 cannot be started, the abnormality content is specified based on a predetermined abnormality determination condition for each abnormality content, and the starter is driven after the abnormality determination condition is satisfied according to the specified abnormality content. The time until the stop command is made variable. Therefore, the starter 10 can be stopped from driving at an appropriate timing according to the cause that the engine 20 cannot be started. As a result, it is possible to optimize the engine start control.

  In the case where the cause that the engine 20 cannot be started is poor meshing, the stop of the starter 10 is instructed immediately after the abnormality is specified. Thereby, it is possible to avoid starter driving in a situation where cranking of the engine 20 cannot be performed and starter driving in a situation where the pinion 14 and the ring gear 25 may be worn.

  When the cause of the failure of starting the engine 20 is continuous cranking or continuous lock, the starter 10 is stopped after a predetermined delay time (Tdy1, Tdy2) has elapsed after specifying the abnormality and storing the abnormality occurrence information. Is configured to command. In this case, since a grace period is provided between the time when the abnormal content is specified and the starter drive is forcibly stopped, the start period of cranking by the starter 10 becomes longer, and as a result, the possibility of starting the engine is increased. Can do.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be implemented as follows, for example.

  Of the abnormality determination conditions for meshing failure, regarding condition (c2), it is determined that the condition (c2) is satisfied when the engine speed NE is 0 and NE = 0 continues for a predetermined time. The rotational speed and the motor rotational speed may be detected by a sensor or the like, respectively, and determination may be made based on the comparison result. At this time, when the relative rotational speed difference of the motor rotational speed with respect to the ring gear rotational speed is larger than the determination value, it may be determined that the above (c2) is established.

  -About continuous cranking and continuous lock, it is good also as a structure which refers the past log | history of abnormality occurrence information and sets delay time based on the log | history. For example, the delay time is set to zero when the number of times the continuous cranking occurrence flag fb and the continuous lock occurrence flag fc are switched on exceeds a determination value. That is, the starter drive is forcibly stopped immediately after the flag is turned on. Alternatively, the delay time may be shortened as the number of times of switching increases.

  -The determination method of a meshing failure may be other than the success or failure of the condition (c1) and the condition (c2). For example, engagement determination means such as a sensor for determining whether or not the engagement of the pinion 14 and the ring gear 25 has occurred is provided, and the pinion 14 and the ring gear 25 are engaged based on the determination result by the engagement determination means. It is determined whether or not. Specifically, for example, a sensor is arranged in the vicinity of the pinion 14 or the ring gear 25, and the determination is made using the detection value of the sensor. Further, a configuration may be adopted in which energization is possible between the two gears in a state where the pinion 14 and the ring gear 25 are engaged, and when the energization is performed, it is determined that the engagement between the pinion 14 and the ring gear 25 is completed.

  A cylinder pressure sensor that detects the cylinder pressure of the engine 20 and a torque sensor that detects the output torque of the engine 20 are provided, and the success or failure of the condition (d2) in continuous cranking is determined based on the detection results of these sensors. It is good also as a structure. In short, the condition (d2) may be any as long as it determines that the combustion of the engine 20 has started normally with the start of fuel injection and ignition at the time of engine start.

  In the above embodiment, the case where an abnormality has occurred at the time of engine restart by idle stop control has been described, but the present invention may be applied to the case of engine start by key operation.

  In the above embodiment, the case where the starter 10 capable of independently controlling the push-out of the pinion 14 and the drive of the motor 11 is applied to the present invention, but the motor 11 is driven by pushing out the pinion 14. A conventional starter may be applied to the present invention.

  -Although the case where a gasoline engine was applied was demonstrated, the structure which applies a diesel engine to this invention may be sufficient.

  DESCRIPTION OF SYMBOLS 10 ... Starter, 11 ... Motor, 14 ... Pinion, 20 ... Engine, 24 ... Crankshaft, 25 ... Ring gear, 27 ... SL1 drive relay, 28 ... SL2 drive relay, 40 ... ECU (abnormality diagnosis means, starter control means), SL1 ... actuator, SL2 ... motor switch.

Claims (5)

When starting the engine, the pinion of the starter is moved toward the ring gear connected to the engine output shaft to cause the engagement of the pinion and the ring gear, and the engine is rotated by the rotation of the motor of the starter. In the engine start control device that stops the cranking by stopping the drive of the starter,
Based on the success or failure of an abnormality determination condition determined for each diagnosis object, with a plurality of abnormality contents occurring after the start of the movement of the pinion and the rotation of the motor and before the end of the cranking as a diagnosis object An abnormality diagnosis means for performing an abnormality diagnosis;
Starter control means for commanding stop of driving of the starter when an abnormality determination condition of any of the plurality of abnormality contents is established by the abnormality diagnosis means and it is diagnosed that there is an abnormality, and
The starter control means varies the time from when the abnormality determination condition is satisfied until the start of driving of the starter is commanded according to the abnormality content diagnosed as abnormal by the abnormality diagnosis means. An engine start control device. As an object to be diagnosed by the abnormality diagnosing means, including a meshing failure between the pinion and the ring gear after the start of movement of the pinion,
The starter control unit stores abnormality occurrence information indicating that an abnormality has occurred when an abnormality determination condition for determining the meshing failure is established and is diagnosed as having an abnormality, and immediately after the abnormality determination condition is satisfied, The engine start control device according to claim 1, wherein the start of the starter is commanded to stop.   As an abnormality determination condition for determining the meshing failure, the rotational load of the motor after the start of rotation of the motor is smaller than that at the time of cranking, and the tooth speed of the pinion is smaller than the passing speed of the tooth portion of the ring gear. The engine start control device according to claim 2, wherein the passage speed is higher. As the diagnosis object of the abnormality diagnosis means, including continuous cranking that is an abnormality in which a predetermined time elapses while the cranking of the engine by the starter is continued,
The starter control unit stores abnormality occurrence information indicating that an abnormality has occurred when an abnormality determination condition for determining the continuous cranking is satisfied and is diagnosed as having an abnormality, and after the abnormality determination condition is satisfied, The engine start control device according to any one of claims 1 to 3, wherein the start of the starter is instructed after the first delay time has elapsed. As an object to be diagnosed by the abnormality diagnosing means, including a non-rotation abnormality that is an abnormality in which the engine speed does not increase in the state where the meshing occurs,
When the abnormality determination condition for determining the non-rotation abnormality is established and the abnormality is diagnosed, the starter control means stores abnormality occurrence information indicating that an abnormality has occurred, and after establishment of the abnormality determination condition, The engine start control device according to any one of claims 1 to 4, wherein the start of the starter is commanded after the second delay time has elapsed.

Images