JP4214401B2 - Engine automatic stop / restart device - Google Patents

Description

  The present invention relates to an engine automatic stop / restart device that automatically stops and restarts an engine.

  Some recent automobiles are equipped with an engine automatic stop / restart device (so-called idling stop device) in order to reduce fuel consumption and exhaust emissions. This automatic engine stop / restart device automatically stops the engine when the driver stops the vehicle, and then the driver tries to start the vehicle (for example, to the brake release operation, drive range, etc.). When the shift operation is performed, a restart request is generated and the engine is automatically restarted.

At the time of restart, as shown in Patent Document 1 (Japanese Patent Laid-Open No. 2002-122059), a pinion that is rotationally driven by a starter is pushed out by an electromagnetic actuator (plunger coil), and the pinion is connected to the crankshaft of the engine. After being engaged with the ring gear, the engine is cranked and restarted by energizing the starter and rotating the pinion to rotate the ring gear. When the pinion is pushed out, the pinion does not mesh with the ring gear and the tip of the pinion may be in contact with the side surface of the ring gear. In this case, the starter is then energized to rotate the pinion. Then, when the pinion is rotated by an amount corresponding to the displacement of the mesh with the ring gear, the pinion is engaged with the ring gear by the pushing force of the electromagnetic actuator, and cranking is started.
Japanese Patent Laid-Open No. 2002-122059 (pages 2 to 3 etc.)

  Such an engine automatic stop / restart device is required to restart the engine as quickly as possible when a restart request is generated.

  However, in the conventional engine automatic stop / restart device, the pinion is pushed out when the engine rotation is completely stopped by the automatic stop or is in an extremely low rotation state that can be regarded as almost stopped. Since the ring gear is engaged, even if a restart request is generated during the engine rotation descent period immediately after the automatic stop request is generated, the engine rotation is completely stopped or can be regarded as almost stopped. The above-mentioned restart control is started after waiting for a very low rotation state. For this reason, there is a time delay from the occurrence of the restart request to the start of cranking, which causes the driver to feel that the restart is slow.

  The present invention has been made in view of such circumstances. Therefore, the object of the present invention is not to wait for the engine rotation to stop when a restart request is generated during the engine rotation descent period immediately after the automatic stop request is generated. It is an object of the present invention to provide an automatic engine stop / restart device that can start cranking by causing a pinion to be engaged with a ring gear without causing the driver to feel that restart is slow.

In order to achieve the above object, the invention according to claim 1 includes a ring gear connected to a crankshaft of an engine, a pinion rotated by a starter, and the pinion from a stand-by position disengaged from the ring gear. In an engine automatic stop / restart device having a pinion pushing means for biting into a ring gear, a ring gear rotational speed judging means for judging the rotational speed of the ring gear, and a pinion rotational speed judgment for judging the rotational speed of the pinion Means for starting the energization of the starter and rotating the pinion when a restart request is generated during the engine rotation descent period from when the automatic stop request is generated until the engine rotation is stopped. When the rotation speed of the ring gear is synchronized with the rotation speed of the ring gear, the pinion pushing means The emissions by bitten the ring gear to start the cranking by the starter to the first, characterized in that the engine is restarted, further future ring gear based on the determination result of the ring gear rotation speed determining means Predict the rotation speed, predict when the rotation speed of the pinion synchronizes with the rotation speed of the ring gear, and start the extrusion speed and / or the extrusion of the pinion extrusion means so that the pinion is engaged with the ring gear at that time Controlling the timing is a second feature.

  In short, even if the ring gear (engine) is rotating, the pinion can be engaged with the ring gear if the rotation speed of the pinion is synchronized with the rotation speed of the ring gear. Focusing on this point, the present invention synchronizes the rotation speed of the pinion with the rotation speed of the ring gear when the restart request is generated during the engine rotation descent period immediately after the automatic stop request is generated. At this point, the pinion is engaged with the ring gear and cranking is started. Therefore, when a restart request is generated during the engine rotation drop period immediately after the automatic stop request is generated, the engine rotation is completely stopped. Without waiting for this to occur, the pinion can be quickly bitten into the ring gear to start cranking, so that the driver does not feel that restart is slow.

  In this case, since the pinion travel time is delayed from the start of the pinion extrusion until the pinion reaches the ring gear, the pinion rotation speed is immediately synchronized with the ring gear rotation speed. Even if the extrusion is started, if the rotational drop amount of the ring gear during the movement time of the pinion becomes large, the pinion and the ring gear may not be synchronized, and the pinion may fail to be engaged.

As a countermeasure, as claimed in claim 1, in anticipation of the ring gear rotation speed of the future based on the determination result of the ring gear rotation speed determining means predicts the time when the rotational speed of the pinion is synchronized with the ring gear rotation speed , and reliably pinion when you lever to control the extrusion speed and / or extrusion start timing of the pinion pushing means to cause caught the pinion to the ring gear in accordance with the time, the pinion reaches the ring gear Since it can be controlled so that it synchronizes with the ring gear, the pinion can be used as a ring gear even if the rotational drop of the ring gear during the pinion movement time increases (or even if the pinion movement time increases). It can be securely bitten.

Further, as in claims 2 and 4 , when a restart request is generated during the engine rotation descent period, the pinion is pushed out to the position just before the pinion is engaged with the ring gear before the synchronization is established. It is possible to wait, and when the synchronization is established, the pinion may be engaged with the ring gear by the pinion pushing means. In this way, if the pinion is pushed to the position just before it is bitten into the ring gear and kept waiting, the pinion can be bitten into the ring gear with the shortest movement distance when synchronization is established. When the condition is established, the pinion can be quickly bitten into the ring gear, and the pinion can be surely bitten into the ring gear.

Further, as described in claims 3 and 5 , when a restart request is generated during the engine rotation descent period, the pinion pushing means starts pushing out the pinion before the synchronization is established, and the pinion is engaged with the ring gear. It is also possible to control the push-out speed and / or push-out start timing of the pinion push-out means so that the pinion is engaged with the ring gear when the synchronization is established without waiting at the position immediately before. In this way, since the pinion and the ring gear can be controlled to be synchronized when reaching the position just before the pinion is engaged with the ring gear, the pinion is quickly connected to the ring gear when the synchronization is established. So that the pinion can be reliably bitten into the ring gear. Moreover, since the pinion continues to be pushed out before the pinion is finally bited into the ring gear (before synchronization is established), when the pinion is finally bited into the ring gear, the influence of inertia and static friction force is affected. Less, the pinion can be bitten into the ring gear in a very short time.

Further, as in claims 6 and 7 , when a restart request is generated during the engine rotation drop period, the rotation speed of the pinion is controlled to increase to the target synchronous rotation speed, and the rotation speed of the ring gear is set to the target speed. You may make it judge that the said synchronization was materialized when it fell to synchronous rotation speed. In this case, the target synchronous rotation speed is preferably set to a rotation speed at which the pinion can be easily bitten. This target synchronous rotational speed may be set to the same speed every time in order to simplify the arithmetic processing, but the target synchronous rotational speed is based on the rotational speed of the ring gear at the time when the restart request is generated during the engine rotational descent period. The speed may be set (for example, the target synchronous rotational speed may be set to a speed lower than the rotational speed of the ring gear when the restart request is generated).

Alternatively, as in claim 8 , when a restart request is generated during the engine rotation descent period, the rotation speed of the pinion is controlled so that the rotation speed of the pinion is increased within a controllable range. It may be determined that synchronization has been established when the rotational speed of the ring gear to be substantially matched. By doing so, there is an advantage that the time until synchronization is established can be shortened, and the time from the occurrence of the restart request to the start of cranking can be shortened.

Also, as in claim 9, 10, control the extrusion speed of the pinion pushing means to push the speed of the pinion is equal to or higher than a speed corresponding to the spatial frequency of the teeth of the ring gear at which to bitten the pinion with the ring gear It is good to do. In this way, even if the synchronization between the pinion and the ring gear is slightly shifted (or even if the conditions for determining synchronization are relaxed), the pinion can be engaged with the ring gear relatively smoothly. There is an advantage that the biting operation can be stabilized.

  Embodiments 1 and 2 embodying the best mode for carrying out the present invention will be described below.

  A first embodiment of the present invention will be described with reference to FIGS. First, the configuration of the engine automatic stop / restart device will be described with reference to FIG. The starter 11 is a so-called pinion extrusion starter, and includes a motor unit 12, a pinion 13 that is rotationally driven by the motor unit 12, an electromagnetic actuator 14 (pinion pushing means) for pushing out the pinion 13, and the like. It has become. The motor unit 12 can control the rotation speed of the pinion 13 by winding the series winding coil 16 and the dividing coil 17 around the armature 15 in the same direction and controlling the energization current of the dividing coil 17 by duty control or the like. (See FIG. 2).

  The pinion 13 is integrated with the one-way clutch 18 and is connected to a rotation shaft of a speed reduction mechanism (not shown) of the motor unit 12 so as to be movable in the axial direction. The electromagnetic actuator 14 that pushes out the pinion 13 at the time of start-up includes a plunger 19 and a plunger coil 20, and the plunger 19 is connected to the one-way clutch 18 via a lever 21. When the plunger coil 20 is energized, the plunger 19 is attracted in the direction of arrow A, whereby the lever 21 rotates about the shaft 22 and the pinion 13 is pushed together with the one-way clutch 18 so that the pinion 13 is It meshes with a ring gear 23 connected to the crankshaft of the engine.

  When the engine speed (the rotational speed of the ring gear 23) exceeds the rotational speed of the pinion 13 at the start and the pinion 13 is driven to rotate by the ring gear 23, the one-way clutch 18 is idled and the starter 11 The motor unit 12 is prevented from being rotated by engine power.

  A normally-open electromagnetic switch 25 is provided between the starter 11 and the battery 24 configured as described above, and the driver operates the ignition switch 26 to a contact at a start position (START position). When turned on, the coil 25a of the electromagnetic switch 25 is energized from the battery 24 to turn on the electromagnetic switch 25, and the series coil 16 and the plunger coil 20 of the starter 11 are energized to start the engine. When the ignition switch 26 is returned from the start position to the on position and the contact at the start position is turned off, the energization to the coil 25a of the electromagnetic switch 25 is cut off, the electromagnetic switch 25 is turned off, and the energization to the starter 11 is turned off. Is done.

  In the first embodiment, since the starter 11 is automatically energized when a restart request is generated during the automatic engine stop period, the energization to the starter 11 can be controlled by the controller 27 (restart control means). It has become. The controller 27 duty-controls the output port P1 for turning on / off the energization of the coil 25a of the electromagnetic switch 25, the output port P2 for duty-controlling the energization of the plunger coil 20, and the energization of the shunt coil 17. An output port P3 for turning on / off the switching element 28 and an input port for receiving a restart request signal output from the engine ECU 29 (engine control computer) are provided.

  The engine ECU 29 determines that an automatic stop request has occurred when the driver stops the vehicle during engine operation and the stop time exceeds a predetermined time, stops fuel injection and ignition, and stops the engine. Stop automatically. Further, the engine ECU 29 determines that a restart request has occurred when the driver performs an operation (for example, a brake release operation, a shift operation to a drive range, etc.) to start the vehicle during the automatic stop period. Then, a restart request signal is transmitted to the controller 27. The engine automatic stop / restart control by the engine ECU 29 is executed by an engine automatic stop / restart routine shown in FIG.

  On the other hand, the controller 27 automatically restarts the engine when a restart request signal output from the engine ECU 29 is received by executing routines shown in FIGS. 4 and 5 described later. At this time, if a restart request is generated when the engine rotation is completely stopped by the automatic stop or is in an extremely low rotation state that can be regarded as almost stopped, a normal restart routine is performed. (Not shown), the plunger coil 20 is energized immediately, the pinion 13 is pushed out by the plunger 19 and engaged with the ring gear 23, and then the direct-wound coil 16 of the starter 11 is energized to pinion 13 To rotate the ring gear 23 to crank and restart the engine. In addition, when the pinion 13 is pushed out, the pinion 13 may not be engaged with the ring gear 23 and the tip of the pinion 13 may come into contact with the side surface of the ring gear 23. When the series coil 16 is energized to rotate the pinion 13, the pinion 13 is engaged with the ring gear 23 by the pushing force of the plunger 19 when the pinion 13 is rotated by the amount of displacement of the engagement with the ring gear 23. Cranking is started.

  On the other hand, when a restart request is generated during the engine rotation descent period from when the automatic stop request is generated until the engine rotation is stopped, a restart routine during engine rotation descent in FIG. 11 is started, the pinion 13 is rotated, and when it is determined that the rotation speed of the pinion 13 is synchronized with the rotation speed of the ring gear 23, the plunger coil 20 has a maximum duty ratio of 100. % To maximize the pushing force of the pinion 13 and quickly engage the pinion 13 with the ring gear 23, and then energize the series winding coil 16 of the starter 11 to maximize the output of the starter 11 and Crank and restart.

  In the first embodiment, in order to shorten the movement time of the pinion 13 from when the synchronization is established until the pinion 13 is engaged with the ring gear 23, when the restart request is generated during the engine rotation descent period, Before energization is established, energization of the plunger coil 20 is started and the pinion 13 is slowly pushed out so that the tip of the pinion 13 approaches the side surface of the ring gear 23 when synchronization is established. Yes. At this time, in order to prevent the start of movement of the pinion 13 from being delayed by inertia and static friction force, as shown in FIG. 6, the influence of inertia and static friction force is reduced from the start of energization of the plunger coil 20. Until the time t elapses, the plunger coil 20 is energized with a maximum duty ratio of 100% and starts to push out the pinion 13 with the maximum pushing force. After a predetermined time t has elapsed, the duty ratio of the plunger coil 20 is changed to the pinion 13. Is lowered to a duty ratio (D1%) that does not stop, and the pinion 13 is pushed out very slowly so that the pinion 13 approaches the ring gear 23 slowly, and when synchronization is established, the duty ratio of the plunger coil 20 To the maximum duty ratio of 100% to maximize the pushing force of the pinion 13 and ON 13 is to cause caught quickly to the ring gear 23.

The processing contents of the routines shown in FIGS. 3 to 5 will be described below.
The engine automatic stop / restart routine of FIG. 3 is executed by the engine ECU 29 at a predetermined cycle. When this routine is started, it is first determined in step 101 whether or not there is an automatic stop request. If there is no automatic stop request, this routine is terminated as it is. If there is an automatic stop request, step 102 is executed. Then, the engine stop process (fuel injection / ignition stop) is executed to automatically stop the engine.

  Thereafter, the routine proceeds to step 103, where it is determined whether or not there is a restart request. If there is no restart request, this routine is terminated as it is, but if there is a restart request, the routine proceeds to step 104 and the engine ECU 29 Then, a restart request signal is transmitted to the controller 27 and waits until cranking by the starter 11 is started (step 105). When cranking is started, the routine proceeds to step 106 where fuel injection / ignition is executed to start the engine.

  The starter control routine of FIG. 4 is executed by the controller 27 at a predetermined cycle. When this routine is started, first, at step 201, it is determined whether or not there is a restart request (whether or not a restart request signal transmitted from the engine ECU 29 has been received), and there is no restart request. If so, this routine is terminated.

  Thereafter, when it is determined in step 201 that there is a restart request, the process proceeds to step 202, where it is determined whether or not the engine rotation is decreasing (whether or not the engine rotation is stopped). Instead, if it is determined that the engine rotation is stopped, the routine proceeds to step 204, where a normal restart routine (not shown) is executed, the plunger coil 20 is energized immediately, and the pinion 13 is moved by the plunger 19. After being pushed out and engaged with the ring gear 23, the engine is cranked and restarted by energizing the series winding coil 16 of the starter 11 and rotating the pinion 13 to rotationally drive the ring gear 23.

  On the other hand, if it is determined in step 202 that the engine rotation is decreasing, the process proceeds to step 203, and the restart routine during engine rotation decrease in FIG. 5 is executed. When this routine is started, first, at step 301, the engine rotation speed NE after a predetermined time T (s) has elapsed is predicted. Here, the predetermined time T (s) is set to an average time required to synchronize the rotation speed of the pinion 13 with the rotation speed of the ring gear 23 or a time close thereto. A method for predicting the engine rotational speed NE after the elapse of the predetermined time T (s) is, for example, as described in the specification of Japanese Patent Application No. 2003-34580, in which the kinetic energy of the current engine and the engine motion are calculated. Calculate the amount of work to be blocked (pump loss, friction loss of each part, drive loss of each accessory, heat loss, vehicle drive system loss, friction loss with the road surface, etc.) Based on this, the future kinetic energy is predicted, and the future engine speed may be predicted from this future kinetic energy.

  After predicting the engine speed NE after the elapse of the predetermined time T (s), the routine proceeds to step 302 where the engine speed NE after the elapse of the predetermined time T (s) is controlled by the shunt coil 17. Compared with the minimum rotation speed NEmin, if the engine rotation speed NE after a predetermined time T (s) has elapsed is smaller than the controllable minimum rotation speed NEmin, the engine rotation is in an extremely low rotation state that can be regarded as almost stopped. In step 303, the electromagnetic switch 25 is turned on, the energization of the plunger coil 20 is started, the pinion 13 is pushed out by the plunger 19 to be engaged with the ring gear 23, and the series coil of the starter 11 is turned on. 16 is energized to rotate the pinion 13 and rotationally drive the ring gear 23 to crank the engine.

  On the other hand, if it is determined in step 302 that the engine speed NE after the predetermined time T (s) has elapsed is equal to or higher than the controllable minimum speed NEmin, the process proceeds to step 304 and the electromagnetic switch 25 is turned on. While turning on, energization of the plunger coil 20 is started. At the beginning of energization, in order to prevent the start of movement of the pinion 13 from being delayed by inertia and static frictional force, the influence of inertia and static frictional force from the start of energization of the plunger coil 20 as shown in FIG. The energization to the shunt coil 17 is kept off (duty ratio 0%) and the plunger coil 20 is energized with the maximum duty ratio of 100% until a predetermined time t that decreases, and the maximum pushing force is obtained. When the predetermined time t has elapsed (step 305), the process proceeds to step 306, where the duty ratio of the plunger coil 20 is reduced to a duty ratio (D1%) that does not stop the pinion 13. To slow down the extrusion speed of the pinion 13 and push the pinion 13 very slowly to ring the pinion 13 Very to approach slowly to the A 23. This is to prevent the pinion 13 from reaching the ring gear 23 before the rotation speed NEp of the pinion 13 and the rotation speed NEr of the ring gear 23 are synchronized.

  Then, in the next step 307, energization to the shunt coil 17 is started to rotate the pinion 13, and the duty ratio of the shunt coil 17 is determined based on the starter characteristics of FIG. 2, and the rotational speed NEp of the pinion 13 is determined. Is controlled to increase to the target synchronous rotation speed.

  In the subsequent step 308, whether or not the rotational speed NEp of the pinion 13 and the rotational speed NEr of the ring gear 23 are synchronized is determined by whether or not the rotational speed difference | NEr−NEp | is smaller than the synchronization determination value ΔNE. Determine and wait until synchronization is established. Here, the synchronization determination value ΔNE is set to a rotational speed difference at which the pinion 13 can be engaged with the ring gear 23. At this time, the rotational speed NEp of the pinion 13 is calculated based on the energizing current (duty ratio) of the shunt coil 17, and the rotational speed NEr of the ring gear 23 may be calculated based on the engine rotational speed. These functions correspond to the pinion rotation speed determination means and the ring gear rotation speed determination means in the claims.

  Thereafter, when the rotational speed difference | NEr−NEp | between the pinion 13 and the ring gear 23 becomes smaller than the synchronization determination value ΔNE, it is determined that synchronization is established, and the process proceeds to step 309 where the plunger coil 20 is The duty ratio is 100% and the pushing force of the pinion 13 is maximized so that the pinion 13 is quickly engaged with the ring gear 23. In this case, since the pinion 13 is slowly pushed out at a duty ratio D1% before the duty ratio of the plunger coil 20 is set to 100% (before synchronization is established), the duty ratio of the plunger coil 20 is increased to 100%. Sometimes, the influence of inertia and static frictional force is small, and the pinion 13 can be engaged with the ring gear 23 in a very short time.

  Thereafter, the process proceeds to step 310, the energization to the shunt coil 17 is turned off (duty ratio 0%), the maximum current is supplied to the series coil 16, the rotational speed of the pinion 13 is increased, and the maximum output To crank the engine.

  Thereafter, the process proceeds to step 311 where it is determined whether or not the start is completed based on whether or not the engine speed is equal to or higher than the start determination rotation speed, and the cranking is continued until the start is determined to be completed. When it is determined that, the routine proceeds to step 312, where the electromagnetic switch 25 is turned off and the energization to the plunger coil 20 is turned off, the cranking is finished, and this routine is finished.

  In the first embodiment described above, even if the ring gear 23 (engine) is rotating, the pinion 13 is engaged with the ring gear 23 if the rotation speed of the pinion 13 is synchronized with the rotation speed of the ring gear 23. Focusing on the fact that it is possible, when a restart request is generated during the engine rotation descent period immediately after the automatic stop request is generated, the pinion 13 is rotated and the rotation speed of the pinion 13 is adjusted to the rotation of the ring gear 23. When the speed is synchronized with the speed, the pinion 13 is engaged with the ring gear 23 to start cranking, so that the engine rotation is stopped when a restart request is generated during the engine rotation descent period. The pinion 13 can be immediately bitten into the ring gear 23 and cranking can be started without waiting for the engine to start. It is not necessary to let.

  Moreover, in the first embodiment, when a restart request is generated during the engine rotation descent period, the push-out of the pinion 13 is started before the synchronization is established, and the pinion 13 is moved to the ring gear 23 when the synchronization is established. The pinion 13 is pushed out very slowly so as to reach the position immediately before being bitten, and when the synchronization is established, the pushing force of the pinion 13 is maximized so that the pinion 13 is quickly bitten into the ring gear 23. As a result, the pinion 13 can be quickly bitten into the ring gear 23 with the substantially shortest movement distance from the establishment of synchronization, and the pinion 13 can be reliably bitten into the ring gear 23. Moreover, since the pinion 13 is slowly pushed out before the push force of the pinion 13 is maximized (before synchronization is established), there is little influence of inertia and static friction force when the push force of the pinion 13 is maximized. The pinion 13 can be engaged with the ring gear 23 in a very short time.

  In the first embodiment, when the pinion 13 is finally engaged with the ring gear 23, the pushing force of the pinion 13 is maximized (the duty ratio of the plunger coil 20 is 100%), and the pushing speed of the pinion 13 is maximized. However, the push-out speed of the pinion 13 (plunger coil) so that the push-in speed of the pinion 13 when the pinion 13 is engaged with the ring gear 23 is equal to or higher than the speed corresponding to the spatial frequency of the teeth of the ring gear 23 20 duty ratio) may be controlled. In this way, even if the pinion 13 and the ring gear 23 are slightly out of synchronization (or even if the synchronization determination value ΔNE is increased), the pinion 13 can be engaged with the ring gear 23 relatively smoothly. This is advantageous in that the biting operation of the pinion 13 can be stabilized.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, a magnet switch 31 that is turned on / off by the plunger 19 of the electromagnetic actuator 14 is provided in parallel with the electromagnetic switch 25, and energization of the coil 25 a of the electromagnetic switch 25 is controlled by the controller 27. .

  In the second embodiment, instead of the restart routine during the engine rotation drop shown in FIG. 5, the restart routine during the engine rotation drop shown in FIG. 8 is used. In the second embodiment, as in the first embodiment, the engine automatic stop / restart routine of FIG. 3 and the starter control routine of FIG. 4 are executed. If it is determined in steps 201 and 202 of the starter control routine of FIG. 4 that the engine speed is decreasing immediately after the restart request is generated, the process proceeds to step 203 and the restart routine during engine speed reduction of FIG. 8 is executed. To do. When this routine is started, first, in step 401, the electromagnetic switch 25 is turned on, the energization to the shunt coil 17 is maintained off (duty ratio 0%), and the plunger coil 20 has a maximum duty ratio of 100%. The pinion 13 starts to be pushed out with the maximum pushing force, and the maximum current is supplied to the series winding coil 16 to rotate the pinion 13 with the maximum output.

  Thereafter, when a predetermined time t when the influence of the inertia and the static friction force decreases after the start of energization of the plunger coil 20 (step 402), the process proceeds to step 403, and the duty ratio of the plunger coil 20 is changed by the pinion 13 The duty ratio (D1%) is reduced to an extent that does not stop, and the push-out speed of the pinion 13 is reduced, the pinion 13 is pushed out very slowly, and the pinion 13 approaches the ring gear 23 very slowly.

  In the next step 307, the duty ratio of the shunt coil 17 is set to 100%, and the rotational speed NEp of the pinion 13 is reduced. Thereafter, the process proceeds to step 405, where the process waits until the rotational speed NEp of the pinion 13 is reduced below the minimum rotational speed NEmin that can be controlled by the shunt coil 17, and when the rotational speed NEp drops below the controllable minimum rotational speed NEmin, Proceeding to step 406, the rotational speed NEp of the pinion 13 is gradually increased by gradually decreasing the duty ratio of the shunt coil 17 from 100%.

  Then, in the next step 407, whether or not the rotational speed NEp of the pinion 13 and the rotational speed NEr of the ring gear 23 are synchronized is determined by whether the rotational speed difference | NEr−NEp | is smaller than the synchronization determination value ΔNE. Judgment is made based on whether or not and waits until synchronization is established. Here, the synchronization determination value ΔNE is set to a rotational speed difference at which the pinion 13 can be engaged with the ring gear 23.

  Thereafter, when the rotational speed difference | NEr−NEp | between the pinion 13 and the ring gear 23 becomes smaller than the synchronization determination value ΔNE, it is determined that synchronization is established, and the process proceeds to step 408, where the plunger coil 20 has the maximum value. The duty ratio is 100% and the pushing force of the pinion 13 is maximized so that the pinion 13 is quickly engaged with the ring gear 23. At this time, since the pinion 13 is continuously pushed out at a duty ratio D1% before the duty ratio of the plunger coil 20 is set to 100% (before synchronization is established), the duty ratio of the plunger coil 20 is increased to 100%. Sometimes, the influence of inertia and static frictional force is small, and the pinion 13 can be engaged with the ring gear 23 in a very short time.

  Thereafter, the process proceeds to step 409, the energization to the shunt coil 17 is turned off (duty ratio 0%), the maximum current is supplied to the series coil 16, the rotational speed of the pinion 13 is increased, and the maximum output To crank the engine.

  Thereafter, the routine proceeds to step 410, where it is determined whether or not the start is completed based on whether or not the engine rotational speed is equal to or higher than the start determination rotational speed, and the cranking is continued until the start is determined to be completed. When it is determined that the process proceeds to step 411, the electromagnetic switch 25 is turned off, the cranking is finished, and this routine is finished.

  In the second embodiment described above, when the restart request is generated during the engine rotation descent period immediately after the automatic stop request is generated, the rotation speed of the pinion 13 is controlled to be increased within the controllable range, and is increased. Since it is determined that synchronization is established when the difference between the rotational speed of the pinion 13 and the rotational speed of the descending ring gear 23 is smaller than the synchronization determination value ΔNE, synchronization is established from the occurrence of the restart request. There is an advantage that the time from the generation of the restart request to the start of cranking can be shortened. In addition, the same effects as those of the first embodiment can be obtained.

[Other Examples]
In addition to the first and second embodiments, the following embodiments can be considered.
(1) In the first and second embodiments, when the restart request is generated during the engine rotation descent period immediately after the automatic stop request is generated, the push-out of the pinion 13 is started before the synchronization is established. The push-out of the pinion 13 may be started when the synchronization is established. Even in this case, if the pushing speed of the pinion 13 is increased, or the distance between the pinion 13 and the ring gear 23 is shortened to shorten the moving time until the pinion 13 is engaged, the pinion 13 is moved to the ring gear 23. Can be fully bitten.

  (2) When a restart request is generated during the engine rotation descent period immediately after the automatic stop request is generated, the future rotation speed of the ring gear 23 is predicted, and the rotation speed of the pinion 13 is equal to the rotation speed of the ring gear 23. The time of synchronization is predicted, and the push-out speed of the pinion 13 (duty ratio of the plunger coil 20) and / or the push-out start timing is controlled so that the pinion 13 is engaged with the ring gear 23 in accordance with that time. good. In this way, it is possible to control the pinion 13 and the ring gear 23 so that the synchronization between the pinion 13 and the ring gear 23 is ensured when the pinion 13 reaches the ring gear 23. Even if the amount becomes large (or even if the movement time of the pinion 13 becomes long), the pinion 13 can be surely engaged with the ring gear 23.

  (3) In the first and second embodiments, when the restart request is generated during the engine rotation descent period immediately after the automatic stop request is generated, the push-out of the pinion 13 is started before the synchronization is established, The pinion 13 is quickly bitten into the ring gear 23 when synchronization is established, without being stopped at a position immediately before the ring gear 23 is bitten. It is also possible to control both the extrusion speed and the extrusion start timing. When controlling the extrusion start timing, it is only necessary to predict the time until synchronization is established and determine the extrusion start timing in consideration of the movement time until the pinion 13 is bitten.

  (4) When a restart request is generated during the engine rotation descent period immediately after the automatic stop request is generated, the push-out of the pinion 13 is started before the synchronization is established, and immediately before the pinion 13 is engaged with the ring gear 23. The pinion 14 may be pushed to the position and kept waiting, and the pinion 14 may be engaged with the ring gear 23 when synchronization is established.

It is a figure explaining the schematic structure of the whole starter control system of Example 1 of this invention. It is a figure explaining a starter characteristic. 3 is a flowchart illustrating a flow of processing of an engine automatic stop / restart routine according to the first embodiment. 3 is a flowchart illustrating a process flow of a starter control routine according to the first embodiment. 6 is a flowchart showing a flow of processing of a restart routine during engine rotation descent according to the first embodiment. 3 is a time chart illustrating pinion push-out control according to the first embodiment. It is a figure explaining the schematic structure of the whole starter control system of Example 2. FIG. 6 is a flowchart showing a flow of processing of a restart routine during engine rotation descent according to the first embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Starter, 12 ... Motor part, 13 ... Pinion, 14 ... Electromagnetic actuator (pinion pushing means), 16 ... Series winding coil, 17 ... Dividing coil, 19 ... Plunger, 20 ... Plunger coil, 23 ... Ring gear, 25 ... Electromagnetic switch, 26 ... Ignition switch, 27 ... Controller (ring gear rotation speed determination means, pinion rotation speed determination means, restart control means), 29 ... Engine ECU

Claims (10)

Automatic engine stop / restart that automatically stops the engine when an automatic stop request occurs during engine operation and restarts the engine by starting cranking with a starter when a restart request occurs during the automatic stop period In the device
A ring gear connected to the crankshaft of the engine;
A pinion rotated by the starter;
Pinion pushing means for biting the pinion from the standby position out of the ring gear into the ring gear;
A ring gear rotation speed determination means for determining the rotation speed of the ring gear;
Pinion rotation speed determination means for determining the rotation speed of the pinion;
When the restart request is generated during the engine rotation drop period from when the automatic stop request is generated until the engine rotation is stopped, the starter is energized to rotate the pinion, and the rotation of the pinion Restart control means for restarting the engine by starting the cranking by the starter by causing the pinion to be engaged with the ring gear by the pinion pushing means when the speed is synchronized with the rotation speed of the ring gear. ,
The restart control means predicts a future ring gear rotation speed based on a determination result of the ring gear rotation speed determination means, and predicts a time point when the rotation speed of the pinion is synchronized with the ring gear rotation speed, An engine automatic stop / restart apparatus, wherein the push-out speed and / or push-out start timing of the pinion push-out means is controlled so that the pinion is engaged with the ring gear in accordance with the time point. The restart control means pushes out the pinion to a position just before the pinion is engaged with the ring gear before the synchronization is established when the restart request is generated during the engine rotation drop period. 2. The engine automatic stop / restart device according to claim 1, wherein the pinion is engaged with the ring gear by the pinion pushing means when the synchronization is established. The restart control means starts pushing out the pinion by the pinion pushing means before the synchronization is established when the restart request is generated during the engine rotation drop period, and the pinion is transferred to the ring gear. The push-out speed and / or push-out start timing of the pinion push-out means is controlled so that the pinion is bitten into the ring gear when the synchronization is established, without waiting at a position immediately before the biting. The engine automatic stop / restart device according to claim 1 . Automatic engine stop / restart that automatically stops the engine when an automatic stop request occurs during engine operation and restarts the engine by starting cranking with a starter when a restart request occurs during the automatic stop period In the device
A ring gear connected to the crankshaft of the engine;
A pinion rotated by the starter;
Pinion pushing means for biting the pinion from the standby position out of the ring gear into the ring gear;
A ring gear rotation speed determination means for determining the rotation speed of the ring gear;
Pinion rotation speed determination means for determining the rotation speed of the pinion;
When the restart request is generated during the engine rotation drop period from when the automatic stop request is generated until the engine rotation is stopped, the starter is energized to rotate the pinion, and the rotation of the pinion Restart control means for causing the pinion to be engaged with the ring gear by the pinion pushing means when the speed is synchronized with the rotational speed of the ring gear, and starting the cranking by the starter to restart the engine;
With
The restart control means pushes out the pinion to a position just before the pinion is engaged with the ring gear before the synchronization is established when the restart request is generated during the engine rotation drop period. The engine automatic stop / restart device is characterized in that the pinion is engaged with the ring gear by the pinion pushing means when the synchronization is established. Automatic engine stop / restart that automatically stops the engine when an automatic stop request occurs during engine operation and restarts the engine by starting cranking with a starter when a restart request occurs during the automatic stop period In the device
A ring gear connected to the crankshaft of the engine;
A pinion rotated by the starter;
Pinion pushing means for biting the pinion from the standby position out of the ring gear into the ring gear;
A ring gear rotation speed determination means for determining the rotation speed of the ring gear;
Pinion rotation speed determination means for determining the rotation speed of the pinion;
When the restart request is generated during the engine rotation drop period from when the automatic stop request is generated until the engine rotation is stopped, the starter is energized to rotate the pinion, and the rotation of the pinion Restart control means for causing the pinion to be engaged with the ring gear by the pinion pushing means when the speed is synchronized with the rotational speed of the ring gear, and starting the cranking by the starter to restart the engine;
With
The restart control means starts pushing out the pinion by the pinion pushing means before the synchronization is established when the restart request is generated during the engine rotation drop period, and the pinion is transferred to the ring gear. The push-out speed and / or push-out start timing of the pinion push-out means is controlled so that the pinion is bitten into the ring gear when the synchronization is established, without waiting at a position immediately before the biting. The engine automatic stop / restart device described in the above. The restart control means controls to increase the rotation speed of the pinion to a target synchronous rotation speed when the restart request is generated during the engine rotation drop period, and the rotation speed of the ring gear is set to the target rotation speed. The engine automatic stop / restart apparatus according to any one of claims 1 to 5 , wherein it is determined that the synchronization is established at the time when the engine speed is lowered to the synchronous rotation speed. Automatic engine stop / restart that automatically stops the engine when an automatic stop request occurs during engine operation and restarts the engine by starting cranking with a starter when a restart request occurs during the automatic stop period In the device
A ring gear connected to the crankshaft of the engine;
A pinion rotated by the starter;
Pinion pushing means for biting the pinion from the standby position out of the ring gear into the ring gear;
A ring gear rotation speed determination means for determining the rotation speed of the ring gear;
Pinion rotation speed determination means for determining the rotation speed of the pinion;
When the restart request is generated during the engine rotation drop period from when the automatic stop request is generated until the engine rotation is stopped, the starter is energized to rotate the pinion, and the rotation of the pinion Restart control means for causing the pinion to be engaged with the ring gear by the pinion pushing means when the speed is synchronized with the rotational speed of the ring gear, and starting the cranking by the starter to restart the engine;
With
The restart control means controls to increase the rotation speed of the pinion to a target synchronous rotation speed when the restart request is generated during the engine rotation drop period, and the rotation speed of the ring gear is set to the target rotation speed. An engine automatic stop / restart device characterized in that it is determined that the synchronization is established at the time when the speed decreases to the synchronous rotation speed. The restart control means controls to increase the rotation speed of the pinion within a controllable range when the restart request is generated during the engine rotation decrease period, and the rotation speed and decrease of the rising pinion The engine automatic stop / restart device according to any one of claims 1 to 5 , wherein it is determined that the synchronization has been established when the rotational speed of the ring gear substantially matches. The restart control means adjusts the pushing speed of the pinion pushing means so that the pushing speed of the pinion when the pinion is engaged with the ring gear is equal to or higher than the speed corresponding to the spatial frequency of the teeth of the ring gear. The engine automatic stop / restart device according to any one of claims 1 to 8 , wherein control is performed. Automatic engine stop / restart that automatically stops the engine when an automatic stop request occurs during engine operation and restarts the engine by starting cranking with a starter when a restart request occurs during the automatic stop period In the device
A ring gear connected to the crankshaft of the engine;
A pinion rotated by the starter;
Pinion pushing means for biting the pinion from the standby position out of the ring gear into the ring gear;
A ring gear rotation speed determination means for determining the rotation speed of the ring gear;
Pinion rotation speed determination means for determining the rotation speed of the pinion;
When the restart request is generated during the engine rotation drop period from when the automatic stop request is generated until the engine rotation is stopped, the starter is energized to rotate the pinion, and the rotation of the pinion Restart control means for causing the pinion to be engaged with the ring gear by the pinion pushing means when the speed is synchronized with the rotational speed of the ring gear, and starting the cranking by the starter to restart the engine;
With
The restart control means adjusts the pushing speed of the pinion pushing means so that the pushing speed of the pinion when the pinion is engaged with the ring gear is equal to or higher than the speed corresponding to the spatial frequency of the teeth of the ring gear. An engine automatic stop / restart device characterized by controlling.

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