JP2012062768A - Engine stop/start control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drive a starter in an appropriate mode according to a situation at the time.SOLUTION: An ECU 40 calculates a predicted engine rotation speed during a rotation drop period upon automatic stopping of an engine, controls, when a restart condition is established during the rotation drop period, a motor 11 so that a pinion 14 is in a rotation state at the point of time of engagement, and controls energization of a coil 18 so that the pinion 14 is engaged with a ring gear 22 at the point of time of engagement on the basis of the predicted engine rotation speed. The ECU 40 detects, when the restart condition is established during the engine rotation drop upon automatic stopping of the engine, the change of the engine rotation speed drop mode after the establishment, and stops the engine restart during the rotation drop period, in a case before the movement start of the pinion 14 at the point of time of the detection, and continues the engine restart during the rotation drop period in a case after the movement start of the pinion 14.

Description

  The present invention relates to an engine stop / start control device.

  2. Description of the Related Art Conventionally, there is known an engine control system having a so-called idle stop function that detects an operation for stopping or starting such as an accelerator operation or a brake operation to automatically stop and restart an engine. By this idle stop control, effects such as engine fuel consumption reduction are achieved.

  When an engine restart request occurs, it is desirable to restart the engine as soon as possible after the restart request from the viewpoint of improving drivability, and various techniques have been proposed (for example, patents). Reference 1). In Patent Document 1, when a restart request is generated while the engine speed is decreasing after the combustion of the engine is stopped, the pinion is rotated to synchronize the rotation speed of the pinion with the rotation speed of the ring gear. Meshing with a ring gear is disclosed. Further, in meshing the two, Patent Document 1 predicts a future ring gear rotation speed to predict a time point when the pinion rotation speed is synchronized with the ring gear rotation speed, and meshes the pinion with the ring gear in accordance with the time point. The pinion extrusion timing is controlled.

Japanese Patent Laying-Open No. 2005-330813

  While the engine speed is decreasing due to the stop of combustion, the manner in which the engine speed decreases can vary depending on various factors, such as switching of the gear position and switching on / off of the driving of the auxiliary machinery. Further, when such a variation factor occurs, the predicted engine speed calculated before that is not appropriate. For this reason, when the engine speed fluctuates during the engine speed drop, the meshing based on the predicted engine speed may not be properly performed. On the other hand, even when it is difficult to perform proper meshing, there are situations where it is preferable to mesh the pinion and the ring gear during the engine rotation drop.

  The present invention has been made in view of the above problems, and a main object of the present invention is to provide an engine stop / start control device capable of driving a starter in an appropriate manner according to the situation at that time.

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

  The present invention provides a clutch using a starter including engagement means for moving a pinion toward a ring gear connected to an output shaft of an engine and meshing the pinion with the ring gear, and a motor for applying a rotational force to the pinion. Applies to an engine that is automatically ranked when a predetermined automatic stop condition is satisfied and restarted by the starter when a predetermined restart condition is satisfied after the automatic stop condition is satisfied. A rotation prediction means for calculating a predicted engine rotation speed that is an engine rotation speed after the current time in a rotation drop period in which the engine rotation drop occurs when the engine is automatically stopped, and the restart condition is satisfied in the rotation drop period The pinion is rotated so that the pinion is rotated at the time of meshing. And a starter control means for controlling the meshing means so that the pinion and the ring gear mesh at the time of meshing based on the predicted engine speed calculated by the rotation predicting means. The present invention relates to a stop / start control device. In the first aspect of the present invention, the movement start determination means for determining whether or not the start of the movement of the pinion based on the starter control means is performed in the rotation drop period, and the restart is performed in the rotation decrease period. Rotation change detecting means for detecting that the engine speed decrease mode has changed after the condition is satisfied, and the rotation change detecting means detects that the engine speed decrease mode has been changed, and the movement start determining means When it is determined that the movement of the pinion is not yet started, it is detected that the first control means for stopping the engine restart by the starter control means and the engine speed decrease mode is changed by the rotation change detecting means. And when it is determined by the movement start determining means that the movement of the pinion is after the starter Characterized in that it comprises a second control means for continuing the engine restart by.

  When the drive of auxiliary equipment such as an air conditioner or alternator is switched during the engine rotation drop when the engine is automatically stopped, the load on the engine output shaft changes with the drive, resulting in a decrease in the engine rotation speed. Changes. In this case, the predicted value of the engine rotational speed (predicted engine rotational speed) calculated before that is not appropriate, and in the starter control performed based on the predicted engine rotational speed, the engagement between the pinion and the ring gear cannot be performed properly. There is a fear. In view of this, when the restart condition is satisfied during the rotation drop during the automatic engine stop, the meshing during the engine rotation drop is stopped when the engine speed decrease mode is changed after the restart condition is satisfied. It is possible.

  However, in the above, even if the engine speed reduction mode changes after the restart condition is satisfied, if the pinion starts to move toward the ring gear at the time of the change, the pinion is currently It is difficult to specify the positional relationship between the ring gear and the ring gear (whether they are meshed). Even if the pinion is returned to the original position in the meshed state, the pinion may not be pulled out of the ring gear when both the pinion and the ring gear are rotated together. Therefore, even if the movement of the pinion is stopped, it cannot be determined whether the engagement between the pinion and the ring gear has occurred or whether the engagement has been released, and an indeterminate state occurs.

  In view of this point, in the present invention, when the restart condition is satisfied during the rotation descent at the time of the engine automatic stop, even if the engine speed reduction mode changes after the restart condition is satisfied, the change is not pinion. If the movement is started, the movement of the pinion toward the ring gear by the meshing means is continued. In this way, by positively engaging the pinion and the ring gear, it is possible to avoid an indefinite state of the positional relationship between the pinion and the ring gear. Accordingly, the starter can be driven in an appropriate manner according to the situation at that time.

  In the invention according to claim 2, the rotation change detecting means is a change to the side in which the degree of decrease in the engine rotational speed increases or the side in which the degree of decrease in the engine rotational speed decreases as the change in the descending mode or Detects that the engine speed has changed to the increasing side. Then, the first control means detects that the degree of decrease in the engine rotational speed has been increased by the rotation change detecting means, and determines that the pinion movement is not yet started by the movement start determining means. When the engine restart is stopped by the starter control means, it is detected by the rotation change detection means that the degree of decrease in the engine rotation speed decreases or the engine rotation speed increases. When it is determined by the movement start determination means that the movement of the pinion is not yet started, the engine restart by the starter control means is continued.

  If the rotational speed of the ring gear is lower than the rotational speed of the pinion at the time of meshing, it is conceivable that a shock occurs due to the rapid increase of the rotational speed of the ring gear by the rotational force of the pinion after meshing. Therefore, at the time of meshing, it is desirable that the meshing of both be performed with the rotational speed of the ring gear being higher.

  Here, even when the actual engine rotation speed deviates from the predicted engine rotation speed, when the rate of decrease in engine rotation speed changes to a smaller side, or when the engine rotation speed changes to an increase side, At the time of meshing, the actual engine speed is higher than the predicted engine speed. In this case, the pinion and the ring gear can be engaged with each other while the rotational speed of the ring gear is higher. On the other hand, when the rate of decrease in engine rotation speed changes, the actual engine rotation speed is lower than the predicted engine rotation speed and the ring gear rotation speed is higher at the time of meshing. There is a possibility that they cannot be engaged with each other. In view of this point, in this configuration, in the former case, the meshing during the engine rotation drop is continued, and in the latter case, the meshing during the engine rotation drop is stopped, thereby promptly restarting the engine. However, the occurrence of shock can be suppressed.

1 is an overall schematic configuration diagram of an engine control system. The flowchart which shows the process sequence for determining refusal of implementation of the engine restart by a motor tip drive. The flowchart which shows the process sequence of starter control by a motor tip drive. The time chart which shows the specific aspect (principle) of motor tip drive control. The time chart which shows the specific aspect (exception) of motor tip drive control.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. This embodiment is embodied in an engine stop / 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, a starter 10 is provided with a motor 11, and the motor 11 is rotationally driven by power supply from a battery 12. A pinion 14 is provided on the rotating shaft 13 of the motor 11 so as to be slidable in the axial direction of the rotating shaft 13. In the pinion 14, power transmission is intermittently transmitted between the rotating shaft 13 and the pinion 14. 15 and unity.

  Further, the starter 10 is provided with a first solenoid SL1 constituted by a coil 18 and a plunger 19 so that the pinion 14 is reciprocated in the axial direction of the rotary shaft 13 by energization / non-energization of the coil 18. It has become. Specifically, when the coil 18 is not energized, the pinion 14 is arranged in a non-contact state with respect to the ring gear 22 connected to the output shaft (crankshaft) 21 of the engine 20. When the coil 18 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 22. As a result, the tooth portion of the pinion 14 and the tooth portion of the ring gear 22 are engaged, and power transmission from the pinion 14 to the ring gear 22 is possible.

  When the energization of the coil 18 is interrupted while the pinion 14 and the ring gear 22 are engaged, the pinion 14 moves in a direction opposite to the direction toward the ring gear 22 by the biasing force of a spring (not shown). As a result, the engagement between the pinion 14 and the ring gear 22 is released, and the two are brought into a non-contact state.

  An IG switch 23 is provided between the starter 10 and the battery 12, and the starter 10 can be energized from the battery 12 by turning on the IG switch 23 based on the operation of the driver. In addition, an SL1 drive relay 24 that switches between energization / non-energization of the first solenoid SL1 based on a control signal is provided between the coil 18 and the battery 12, and between the motor 11 and the battery 12, A second solenoid SL2 connected to the electromagnetic element of the motor 11 and switched between energization / non-energization by opening and closing a contact and an SL2 drive relay 25 switching between energization / non-energization of the second solenoid SL2 based on a control signal are provided. Yes.

  In addition, the present system includes a crank angle sensor 31 that outputs a rectangular crank angle signal for every predetermined crank angle of the engine 20 (for example, in a cycle of 30 ° CA), and a cooling water temperature sensor 32 that detects the temperature of engine cooling water. Various sensors such as are provided. Although not shown, a manual transmission is connected between the crankshaft 21 and the axle via a clutch device.

  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. The idle stop control is to automatically stop the engine 20 when a predetermined stop condition is satisfied during the idling operation of the engine 20 and restart the engine 20 when a predetermined restart condition is satisfied thereafter. The engine stop condition is, for example, that the accelerator operation amount has become zero (becomes idle), that the brake pedal has been depressed, or that the vehicle speed has decreased to a predetermined value or less. Is included.

  Further, the engine restart condition includes the start of a clutch pedal depressing release operation (clutch release operation), and when the driver starts depressing the depressing from the state where the driver fully depresses the clutch pedal in the engine rotation stopped state. The engine restart condition is met. In addition, the engine restart condition includes, for example, that the accelerator is depressed, the brake operation amount is 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 24, and an output port P2 that outputs an on / off signal of the SL2 drive relay 25. With the control signals from the output ports P1 and P2, the energization state of the starter 10 can be switched, and the energization states of the motor 11 and the coil 18 can be individually switched.

  In the present embodiment, engine combustion is stopped when the automatic stop condition is satisfied, and the engine output shaft 21 stops rotating when the engine restart condition is satisfied during the rotation descent period in which the engine speed decreases after the combustion stop. The engine 20 is cranked by the starter 10 without waiting. As one aspect thereof, the ECU 40 allows the motor 11 to engage with the pinion 14 and the ring gear 22 while the pinion 14 is rotated by the motor 11 when the engine speed when the restart condition is satisfied is relatively high. In addition, “motor front drive control” for controlling energization of the coil 18 is performed.

  For details on the motor tip drive control, the ECU 40 uses the current engine speed calculated based on the detection signal of the crank angle sensor 31 and the previous engine rotation speed in the rotation descent period when the engine is automatically stopped, and later than the current time. The engine rotation speed Ne (predicted engine rotation speed) is calculated, and the meshing timing between the pinion 14 and the ring gear 22 is controlled using the predicted engine rotation speed. Specifically, after the restart condition is satisfied, energization of the motor 11 is started at a predetermined timing, and the rotation speed of the pinion 14 is increased. In addition, using the predicted engine rotation speed, a timing at which the difference between the passing speeds of the tooth portions of the pinion 14 and the ring gear 22 (speed difference of the teeth at the meshing location) becomes equal to or less than a predetermined value is calculated. Then, the engagement between the pinion 14 and the ring gear 22 is performed at a timing earlier than the calculation timing by the time required for the pinion 14 to move to the contact position with the ring gear 22 from the start of energization of the coil 18 (required engagement time). The energization of the coil 18 is controlled as shown in FIG. Note that the energization start timing of the motor 11 may be, for example, the timing when the restart condition is satisfied, or may be a timing calculated based on the predicted engine rotation speed.

By the way, the engine speed reduction mode after the combustion of the engine 20 is stopped may vary depending on various factors.
・ When accessories such as air conditioners and alternators are switched from OFF to ON ・ When the brake pedal is rapidly depressed by the driver and the wheels (not shown) are locked ・ When the engine 20 is restarted due to the clutch release operation When an event such as a case where the clutch engagement operation is performed rapidly after the start of the clutch release operation occurs during the engine rotation drop, the rotational load of the engine output shaft 21 changes to the increasing side, and as a result, the engine There are cases where the rate of decrease in the rotational speed is increased. Further, in a system that starts combustion injection and ignition with the establishment of the restart condition, combustion may occur while the engine 20 is rotating down, and the engine rotation speed changes to the increase side or the engine rotation speed decrease rate. May become smaller. In addition, when the auxiliary machinery is switched from on to off, the rate of decrease in engine speed may be small.

  If the engine speed that is not intended by the ECU 40 changes during the engine speed drop during the automatic engine stop, the predicted engine speed calculated before that is not appropriate. Therefore, in the starter control performed based on the predicted engine rotation speed, there is a possibility that the push-out timing of the pinion 14 and the drive timing of the motor 11 cannot be properly controlled.

  Therefore, in this embodiment, when the restart condition is satisfied during the rotation descent at the time of the engine automatic stop, when the engine speed decrease mode changes after the restart condition is satisfied, as a rule, the motor drive control is performed. The engine restart will be stopped. Therefore, for example, if energization of the motor 11 is started at the time when the engine speed reduction mode is changed, the motor 11 is switched to the energization off state.

  However, even if the restart condition is satisfied during the engine rotation drop and the engine speed decrease mode thereafter changes, when the coil 18 is energized at the time of the change, that is, When extrusion of the pinion 14 is started, the energization of the coil 18 is continued as an exception.

  The reason is as follows. That is, in the starter 10, the pinion 14 and the ring gear 22 are engaged by controlling the energization timing of the coil 18. Specifically, the pinion 14 is pushed out toward the ring gear 22 by the start of energization of the coil 18, the end surface of the pinion 14 comes into contact with the end surface of the ring gear 22, and the ring gear 22 moves in the rotational direction of the engine 20 after the contact. As a result, the pinion 14 and the ring gear 22 are engaged with each other. In this case, the time from the start of energization of the coil 18 until the pinion 14 comes into contact with the ring gear 22 is substantially the same every time the pinion 14 is pushed out, whereas the time required for the two to engage each other varies. Therefore, when the engine speed reduction mode changes, it is difficult to specify whether the pinion 14 and the ring gear 22 are currently engaged with each other at the time of the change.

  In the starter 10, the pinion 14 is pushed out to the ring gear 22 side by energization control of the coil 18. On the other hand, when the pinion 14 is returned from the ring gear 22 side, it is performed using a spring force. More specifically, in a state where the tooth part of the pinion 14 and the tooth part of the ring gear 22 mesh with each other, When a gap is formed between the tooth portions, the pinion 14 is returned to the original position before extrusion by the spring force on the starter 10 side. In this case, if both the pinion 14 and the ring gear 22 are rotated together after the pinion 14 and the ring gear 22 are engaged, a gap is formed between the tooth portions even if the coil 18 is turned off. As a result, the pinion 14 may not be pulled out of the ring gear 22. Such a state in which the positional relationship of the pinion 14 with respect to the ring gear 22 is uncertain is desirably avoided from the viewpoint of reliably restarting the engine 20.

  In view of this, in the present embodiment, when the restart condition is satisfied during the rotation descent at the time of the engine automatic stop, even if the engine speed reduction mode changes after the restart condition is satisfied, When the coil 18 is already energized at the time of the change, the energization of the coil 18 is continued as an exception, and the engine is restarted by driving the motor first.

  Hereinafter, a specific aspect of the motor tip drive control of this embodiment will be described with reference to the flowcharts of FIGS. 2 and 3.

  FIG. 2 is a flowchart showing a processing procedure for determining whether or not to execute engine restart by driving the motor ahead. This process is executed by the ECU 40 at predetermined intervals.

  In FIG. 2, in step S <b> 11, it is determined whether or not the engine speed is decreasing after the automatic stop condition is satisfied. When step S11 is YES, it progresses to step S12, and it is determined whether the execution permission conditions of motor tip drive are satisfied. The execution permission condition is that the predicted engine speed can be calculated, and that the engine speed at the time of engagement of the pinion 14 and the ring gear 22 can be equal to or greater than a determination value (when the restart condition is satisfied). The engine speed of the engine is relatively high). When step S12 is YES, it progresses to step S13, and while setting 1 to the motor ahead drive permission flag Fm, it resets the prediction engine rotational speed invalid determination flag Fr to 0.

  In a succeeding step S14, it is determined whether or not the restart condition is satisfied. When step S14 is YES, it progresses to step S15, and it is determined whether the fall mode of engine speed changed after the restart conditions were satisfied. In the present embodiment, it is determined based on the loss energy of the engine 20 whether or not the engine speed reduction mode has changed. For example, when the engine rotational speed decreases in the fuel cut state, the increase or decrease in the loss energy is caused by the engine rotation. This is because it appears prominently in speed fluctuations.

  When step S15 is YES, it progresses to step S16, and 1 is set to the prediction engine rotational speed invalid determination flag Fr. In step S17, it is determined whether or not it is after the start of energization of the coil 18 (after the start of pushing out the pinion 14). Here, the determination is made based on the pinion extrusion flag Fp, and when Fp = 1, it is determined that the energization of the coil 18 has been started.

  When Fp = 0, the process proceeds to step S18, and the motor destination drive permission flag Fm is reset to 0. On the other hand, if Fp = 1, the process proceeds to step S19, the motor destination drive permission flag Fm is kept at 1, and this routine is finished.

  Next, starter control by motor tip drive will be described using the flowchart of FIG. This process is executed by the ECU 40 at predetermined intervals.

  In FIG. 3, in step S <b> 21, it is determined whether 1 is set in the motor destination drive permission flag Fm. When step S21 is NO, this routine is finished as it is. However, when the motor drive permission flag Fm is immediately after switching from 1 to 0 and the SL2 drive relay 25 is on (when the motor energization is started), the SL2 drive relay 25 is switched off. After this, this routine is finished.

  When step S21 is YES, it progresses to step S22 and it is determined whether the prediction engine speed invalid determination flag Fr is reset to 0. When step S22 is YES, it progresses to step S23 and it is determined whether it is after the restart conditions are satisfied. At this time, if the restart condition is satisfied, the process proceeds to step S24, and it is determined whether the pinion push-out flag Fp is reset to 0 or whether the motor 11 is in the energized off state. When step S24 is YES, it progresses to step S25 and it is determined whether it is an energization timing of the motor 11. FIG. When step S25 becomes YES, the SL2 drive relay 25 is switched on in step S26, and energization of the motor 11 is started.

  In step S27, it is determined whether or not it is the push-out timing of the pinion 14, and when step S27 is YES, the SL1 drive relay 24 is switched on in step S28, and energization of the coil 18 is started. In step S29, 1 is set in the pinion extrusion flag Fp, and the process proceeds to step S30 and subsequent steps.

  On the other hand, if 1 is set in the motor destination drive permission flag Fm and 1 is set in the predicted engine rotation speed invalid determination flag Fr, a negative determination is made in step S22. In this case, it progresses to the process after step S30.

  In step S30, it is determined whether or not the engine rotational speed Ne is equal to or higher than the starting rotational speed Nef (for example, 400 to 500 rpm). This starting rotational speed Nef is set to a value higher by a predetermined speed than the cranking rotational speed. Then, the process proceeds to step S31 on condition that the engine rotational speed is equal to or higher than the starting rotational speed Nef, and an off signal is output to the SL1 drive relay 24 and the SL2 drive relay 25. Thereby, the meshing of the pinion 14 and the ring gear 22 is released, and the rotation of the motor 11 is stopped. Further, here, the motor destination drive permission flag Fm, the predicted engine speed invalidity determination flag Fr, and the pinion push-out flag Fp are reset to 0.

  4 and 5 are time charts showing a specific aspect of the motor tip drive processing of the present embodiment. In the following, the principle of the motor tip drive process will be described with reference to FIG. 4, and the exception will be described with reference to FIG. In the figure, (a) shows the transition of success or failure of the restart condition, (b) shows the transition of the motor drive permission flag Fm, and (c) shows the transition of the predicted engine speed invalidity determination flag Fr. (D) shows the on / off transition of the SL1 drive relay 24, and (e) shows the on / off transition of the SL2 drive relay 25. Moreover, the dashed-dotted line in FIG. 5 shows the process in principle.

  If the restart condition is satisfied when the motor front drive permission flag Fm = 1 and the predicted engine rotation speed invalid determination flag Fr = 0 during the engine rotation drop during the automatic engine stop, as shown in FIG. At the establishment timing t11, the SL2 drive relay 25 is switched from OFF to ON. Thereby, rotation of the pinion 14 is started. Thereafter, before the SL1 drive relay 24 is switched on, if the engine speed decrease mode changes due to, for example, driving switching of auxiliary machinery or wheel locking, the predicted engine speed invalidity determination flag at the timing t12. Fr is switched from 0 to 1, and the motor destination drive permission flag Fm is switched from 1 to 0. Further, the SL2 drive relay 25 is switched from on to off in accordance with the switching of the motor destination drive permission flag Fm. Thereby, the drive of the motor 11 is stopped and the engine restart by the motor tip drive control is stopped.

  On the other hand, as shown in FIG. 5, after the restart condition is established, when the SL1 drive relay 24 is switched on at timing t21, and the engine speed decrease mode changes, the timing of the change At t22, the predicted engine speed invalidity determination flag Fr is switched from 0 to 1, but the motor destination drive permission flag Fm is held at 1. Thereby, starter control by motor tip drive processing is continued.

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

  If the restart condition is satisfied during the rotation descent at the time of the engine automatic stop, after the restart condition is satisfied, the mode of decrease in the engine rotation speed is changed, and the energization of the coil 18 is started when the change occurs. In other words, when the push-out of the pinion 14 is started, the engine restart by the motor tip drive control is stopped, whereas the engine speed decrease mode changes after the restart condition is satisfied. However, when the coil 18 is energized at the time of the change, the coil 18 continues to be energized, so that the positional relationship of the pinion 14 with respect to the ring gear 22 is uncertain. Can be avoided. As a result, the starter 10 can be driven in an appropriate manner according to the situation at that time.

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

  -When the restart condition is established and before the push-out of the pinion 14 starts, and the engine speed decrease mode changes, the change in the engine speed decreases toward the side where the engine speed decrease rate increases. In this case, the engine restart due to the motor-driven drive is stopped, and if the engine speed decreases to a lower rate or the engine rotational speed increases, the engine driven by the motor driven The restart is continued. Even when the actual engine speed deviates from the predicted engine speed, if the rate of decrease in the engine speed decreases, or if the engine speed changes to the increase side, It is possible to engage the pinion and the ring gear in a state where the actual engine rotation speed is higher than the predicted engine rotation speed and the rotation speed of the ring gear is higher than the rotation speed of the pinion. On the other hand, when the rate of decrease in engine rotation speed changes, the actual engine rotation speed is lower than the predicted engine rotation speed and the ring gear rotation speed is higher at the time of meshing. In some cases, the two cannot be engaged. In view of this, in this configuration, when the degree of decrease in the engine rotation speed changes to the larger side, the engine restart due to motor-driven driving is stopped, and when the degree of decrease in the engine rotation speed decreases to the side. When the engine speed changes to the increasing side, the engine restart by continuing the motor tip drive is continued, so that the occurrence of shock can be suppressed while prompt engine restart is achieved.

  In the above embodiment, the case where the starter 10 having the SL1 drive relay 24 that controls energization / non-energization of the coil 18 and the SL2 drive relay 25 that controls energization / non-energization of the motor 11 is applied to the present invention will be described. However, any starter that can independently control the meshing release of the pinion 14 and the ring gear 22 and the rotation stop of the motor 11 may be used. For example, a conventional starter provided with a relay for controlling motor energization is used. You may apply to invention. That is, in this configuration, instead of the second solenoid SL2 in the starter 10 of FIG. 1, the plunger 19 is provided with a contact for energizing the motor at the end opposite to the lever 16. In this configuration, a motor energization control relay that can be switched on / off based on a control signal from the ECU 40 is provided between the motor 11 and the battery 12. Also in this configuration, the meshing operation of the pinion 14 and the ring gear 22 and the rotation operation of the motor 11 can be independently controlled by individually controlling the SL1 drive relay 24 and the motor energization control relay. .

  -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, 18 ... Coil (meshing means), 20 ... Engine, 21 ... Crankshaft, 22 ... Ring gear, 24 ... SL1 drive relay, 25 ... SL2 drive relay, 40 ... ECU (rotation) Prediction means, starter driving means, rotation change detection means, movement start determination means, first control means, second control means), SL1... First solenoid (engagement means), SL2.

Claims (2)

Cranking is performed using a starter that includes a meshing means for moving a pinion toward a ring gear connected to an output shaft of an engine and meshing the pinion with the ring gear, and a motor that applies a rotational force to the pinion. And
Applied to an engine that is automatically stopped when a predetermined automatic stop condition is satisfied, and is restarted by the starter when a predetermined restart condition is satisfied after the automatic stop condition is satisfied;
A rotation prediction means for calculating a predicted engine rotation speed that is an engine rotation speed after the current time in a rotation decrease period in which an engine rotation decrease occurs when the engine is automatically stopped;
When the restart condition is satisfied during the rotation descent period, the motor is controlled so that the pinion is rotated at the time of meshing, and based on the predicted engine rotation speed calculated by the rotation prediction means. An engine stop / start control device comprising starter control means for controlling the meshing means so that the pinion and the ring gear mesh with each other at the time of meshing,
In the rotation descent period, movement start determination means for determining whether or not the movement of the pinion is based on the starter control means;
A rotation change detecting means for detecting a change in a lowering mode of the engine rotation speed after the restart condition is satisfied in the rotation drop period;
The engine restart by the starter control means when it is detected by the rotation change detection means that the engine speed reduction mode has changed and the movement start determination means determines that the pinion movement is not yet started. First control means for canceling
The engine restart by the starter control means when it is detected by the rotation change detection means that the engine speed decrease mode has been changed and the movement start determination means determines that the pinion movement has started. Second control means for continuing
An engine stop / start control device comprising: The rotation change detecting means may change the lowering mode to a side where the degree of decrease in the engine rotational speed increases, or a side where the degree of decrease in the engine rotational speed decreases or the side where the engine rotational speed increases. Detect that there was a change,
The first control means is detected by the rotation change detecting means to have changed to a side where the degree of decrease in engine rotation speed is increased, and is determined by the movement start determining means to be before the start of movement of the pinion. In this case, the engine restart by the starter control means is stopped, and it is detected by the rotation change detecting means that the degree of decrease in the engine rotational speed is reduced or the engine rotational speed is increased and the movement is detected. The engine stop / start control device according to claim 1, wherein the engine restart by the starter control means is continued when it is determined by the start determination means that the movement of the pinion is not started.

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