JP2011220279A - On-vehicle driving system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle driving system capable of controlling the restart of an engine according to driver's characteristics.SOLUTION: In the on-vehicle driving system 1, the engine 2 is controlled to restart with a condition of a depressing operation of a clutch pedal 11 when the engine 2 stops and is in the standby state of restarting. At this time, the restarting start time ts of the engine 2 is changed according to a depressing speed v of the clutch pedal 11. Concretely, the control is performed such that the more the restarting start time ts of the engine 2 is delayed the slower the depressing speed v of the clutch pedal 11 becomes.

Description

  The present invention relates to a vehicle drive system, and more particularly to a vehicle drive system that can perform engine restart control in accordance with the characteristics of a driver.

  In recent vehicle drive systems, when the engine is stopped and in a restart standby state (for example, idling stop state, free-running state, etc.), the engine is restarted under the condition that the clutch pedal is depressed. Has been done. As a conventional vehicle drive system employing such a configuration, a technique described in Patent Document 1 is known.

JP-A-8-291725

  However, the conventional vehicle drive system does not consider the relationship between the time when the engine restart is completed and the engine is idling and the time when the shift of the clutch pedal is completed and the shift position can be changed. . For this reason, there is a problem that engine restart control cannot be performed according to the driver's characteristics (for example, the depression speed of the clutch pedal).

  Therefore, the present invention has been made in view of the above, and an object of the present invention is to provide a vehicle drive system that can perform engine restart control in accordance with the characteristics of the driver.

  In order to achieve the above object, a vehicle drive system according to the present invention is a vehicle drive system that performs control to restart an engine on the condition that a clutch pedal is depressed when the engine is stopped and in a standby state for restart. A drive system comprising a means for calculating an engine restart start time according to a depression speed of a clutch pedal.

  In this vehicle drive system, since the engine restart start time is changed according to the depression speed of the clutch pedal, the time when the engine restart is completed and the engine enters an idling state, and the depression of the clutch pedal is completed. The relationship with the time at which the shift position can be changed can be adjusted. Thereby, there exists an advantage which can perform engine restart control according to a driver | operator's characteristic (pressing speed of a clutch pedal).

FIG. 1 is a configuration diagram showing a vehicle drive system according to an embodiment of the present invention. FIG. 2 is a flowchart showing the operation of the vehicle drive system shown in FIG. FIG. 3 is an explanatory diagram showing the operation of the vehicle drive system shown in FIG. FIG. 4 is a flowchart showing a modification of the restart start time calculating step shown in FIG. FIG. 5 is a timing chart showing an embodiment of the vehicle drive system shown in FIG. FIG. 6 is a timing chart showing an embodiment of the vehicle drive system shown in FIG.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Further, the constituent elements of this embodiment include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. In addition, a plurality of modifications described in this embodiment can be arbitrarily combined within a range obvious to those skilled in the art.

[Vehicle drive system]
FIG. 1 is a configuration diagram showing a vehicle drive system according to an embodiment of the present invention. The vehicle drive system 1 is applied to, for example, a vehicle that can perform eco-run traveling in which the engine 2 is automatically stopped and restarted. The vehicle drive system 1 includes an engine 2, a clutch mechanism 3, a transmission 4, and a control unit 5.

  The engine 2 is a power source that generates driving torque, and is constituted by, for example, an internal combustion engine. A starter 22 is connected to the output shaft (crankshaft) 21 of the engine 2. The starter 22 is an electric motor for starting the engine 2 and is connected to the battery 6 to receive power supply. The clutch mechanism 3 is a friction engagement element that turns ON / OFF transmission of drive torque from the engine 2 to the transmission 4, and is arranged by connecting the output shaft 21 of the engine 2 and the input shaft 41 of the transmission 4. The The clutch mechanism 3 is operated by the clutch pedal 11 in the driver's seat to switch the clutch engaged state and the released state. The transmission 4 is a manual transmission, and changes the rotational speed of the input shaft 41 and outputs it to the output shaft 42. The transmission 4 is operated by the shift lever device 12 in the driver's seat and changes its gear position.

  The control unit 5 includes, for example, an ECU (Electronic Control Unit) 51 and various sensors 521 to 523. The ECU 51 includes an eco-run control unit 511 that performs a series of eco-run control described later, a stepping-speed calculation unit 512 that calculates a stepping speed v of the clutch pedal 11, and a restart start time calculation that calculates a restart start time ts of the engine 2. 513, a depression completion time estimation unit 514 that estimates the depression completion time tc of the clutch pedal 11, and a storage unit 515 that stores predetermined information (for example, the control map of FIG. 3). The various sensors 521 to 523 include, for example, a clutch pedal sensor 521 that detects whether or not the clutch pedal 11 is depressed, a clutch stroke amount sensor 522 that detects the depression amount x of the clutch pedal 11, and a shift position of the shift lever device 12. Shift position sensor 523 and the like. The control unit 5 performs eco-run control and starter energization control, which will be described later, based on the output values of the various sensors 521 to 523.

  The output shaft 21 of the engine 2 is connected to a compressor driving motor 7 of an air conditioner (not shown), a generator alternator 8 and the like. The battery 6 is connected to a starter 22, an alternator 8, a voltage stabilization circuit 9, and the like of the engine 2.

  In the vehicle drive system 1, drive torque from the engine 2 is transmitted to the vehicle wheel 10 via the clutch mechanism 3 and the transmission 4. Thereby, the wheel 10 rotates and the vehicle travels.

  Further, when the shift position is changed, the clutch pedal 11 in the driver's seat is depressed, the clutch mechanism 3 is released, and torque transmission from the engine 2 to the transmission 4 is interrupted. In this state, the shift lever device 12 in the driver's seat is operated to change the shift position, and the transmission 4 switches the gear position. Thereafter, the clutch pedal 11 is returned and the clutch mechanism 3 is engaged, and torque transmission from the engine 2 to the transmission 4 becomes possible. Thereby, the change of the shift position is completed.

  Further, during eco-run traveling, eco-run control is performed in which the engine 2 is automatically stopped and restarted. For example, under the condition that the vehicle is stopped while waiting for a signal, the control unit 5 operates on the condition that the gear position of the transmission 4 is in the neutral position and the clutch pedal 11 is returned (OFF state). The engine 2 is stopped (idling stop). The control unit 5 drives the starter 22 to restart the engine 2 on condition that the clutch pedal 11 is subsequently depressed (clutch flag ON). Thereby, fuel consumption can be reduced, and exhaust emission can be reduced.

[Starter energization control during eco-run driving]
Here, in a general vehicle drive system, when the engine is restarted during eco-run, the starter is driven simultaneously with the start of the depression of the clutch pedal to restart the engine in order to prevent engine start delay. Yes.

  However, there is a difference in the time required to complete the depression of the clutch pedal between a driver with a fast clutch pedal depression speed and a slow driver. For this reason, when the depression speed of the clutch pedal is slow, the standby time (idling time) from the completion of the engine restart to the completion of the depression of the clutch pedal becomes long, and the fuel consumption may increase.

  Therefore, in this vehicle drive system 1, in order to shorten the waiting time from completion of restart of the engine 2 to completion of depression of the clutch pedal 11, the restart start time of the engine 2 is set in accordance with the depression speed of the clutch pedal 11. Control to be changed (starter energization control during eco-run traveling) is performed. This control is performed, for example, as follows (see FIG. 2).

  In step ST1, it is determined whether or not a restart condition for the engine 2 is satisfied. That is, during the eco-run control, when the engine 2 is stopped and in a restart standby state, it is determined whether or not the restart condition of the engine 2 is satisfied. For example, in this embodiment, the start of depression of the clutch pedal 11 (clutch flag ON) is set as the restart condition of the engine 2. The start of depression of the clutch pedal 11 is determined based on the output value of the clutch pedal sensor 521. If an affirmative determination is made in step ST1, the process proceeds to step ST2, and if a negative determination is made, the process ends.

  In step ST2, the time t that defines the restart start time of the engine 2 is reset to t = 0 due to the establishment of the restart condition of the engine 2 (affirmative determination in step ST1). After this step ST2, the process proceeds to step ST3.

  In step ST3, the depression amount x of the clutch pedal 11 is acquired. The depression amount x of the clutch pedal 11 is acquired as an output value of the clutch stroke amount sensor 522. After this step ST3, the process proceeds to step ST4.

  In step ST4, the depression speed v of the clutch pedal 11 is calculated (depression speed calculation step ST4). The depression speed v of the clutch pedal 11 is calculated as, for example, the rate of change Δx / Δt of the depression amount x of the clutch pedal 11 during a predetermined sampling period Δt. After this step ST4, the process proceeds to step ST5.

  In step ST5, it is determined whether or not the depression speed v of the clutch pedal 11 is equal to or higher than a predetermined threshold value k (v ≧ k). If an affirmative determination is made in step ST5, the process proceeds to step ST8, and if a negative determination is made, the process proceeds to step ST6. That is, when the depression speed v of the clutch pedal 11 is fast (v ≧ k), step ST6 and step ST7 are omitted, and the restart of the engine 2 is immediately started (step ST8).

  In step ST6, the restart start time ts of the engine 2 is calculated (restart start time calculating step ST6). This restart start time ts is equal to a waiting time ΔTw from time t = 0 when the restart condition of the engine 2 is satisfied to time t = ts when the restart of the engine 2 is started. For example, in this embodiment, the control unit 5 creates a predetermined control map (see FIG. 3) that defines the relationship between the depression speed v of the clutch pedal 11 and the waiting time ΔTw until the restart start time ts of the engine 2. And the restart start time ts of the engine 2 is calculated based on this control map. After step ST6, the process proceeds to step ST7.

  In step ST7, the engine 2 is in a standby state for starting restart until the time t reaches time t = ts. After this step ST7, the process proceeds to step ST8 (restart standby step ST7).

  In step ST8, restart of the engine 2 is started (restart start step ST8). Specifically, energization to the starter 22 is started and the engine 2 is started. Note that the time ΔTs from the restart start time ts of the engine 2 (starting time of energization to the starter 22) ts to the restart completion time te of the engine 2 is usually constant.

  Then, simultaneously with completion of restart of the engine 2 or after completion of restart of the engine 2, the depression of the clutch pedal 11 is completed, and the clutch mechanism 3 is released. Thereafter, the shift lever device 12 is operated to change the shift position, and the gear position of the transmission 4 is changed.

  In this vehicle drive system 1, the control unit 5 changes the restart start time ts of the engine 2 according to the depression speed v of the clutch pedal 11 (step ST3 and step ST6) (see FIG. 2). Therefore, the relationship between the time when the restart of the engine 2 is completed and the engine becomes idling and the time when the clutch pedal 11 is completely depressed and the shift position can be changed can be adjusted. Thereby, for example, since control for shortening the idling time ΔTe can be performed, fuel consumption of the vehicle can be reduced and fuel consumption can be improved.

  In this embodiment, the control map is set so that the restart start time ts of the engine 2 is delayed as the depression speed v of the clutch pedal 11 is slower (see FIG. 3). Therefore, the difference ΔTi = te−tc between the time te when the restart of the engine 2 is completed and the idling state is completed and the time tc when the depression of the clutch pedal 11 is completed and the shift position can be changed becomes small. Thereby, the useless idling time ΔTi is shortened, and the fuel consumption of the engine 2 is reduced.

  In this embodiment, when the depression speed v of the clutch pedal 11 is sufficiently high (v ≧ k) (affirmative determination in step ST5), restart of the engine 2 is immediately started (step ST8). In this case, the situation is almost the same as the configuration in which the starter 22 is driven and the engine 2 is restarted simultaneously with the start of depression of the clutch pedal 11 (clutch flag ON). This prevents a delay in starting the engine when the shift position is changed.

[Modification of calculation method of restart start time]
Further, in this embodiment, in the restart start time calculating step ST6, a predetermined control map that defines the relationship between the depression speed v of the clutch pedal 11 and the waiting time ΔTw until the restart start time ts of the engine 2 ( The restart start time ts of the engine 2 is calculated using FIG. In such a configuration, the restart start time ts of the engine 2 can be uniquely set based on the control map, which is preferable in that the restart start time ts can be easily calculated and the configuration of the control unit 5 can be simplified. .

  The control map is defined based on the test data so that the restart completion time te of the engine 2 is simultaneously with or immediately before the depression completion time tc of the clutch pedal 11. As a result, the idling time ΔTi from the restart completion time te of the engine 2 to the depression completion time tc of the clutch pedal 11 is shortened, and the fuel consumption of the engine 2 is reduced.

  However, the present invention is not limited to this, and the restart start time calculating step ST6 may be performed as follows (see FIG. 4).

  In step ST61, an estimated value of the depression completion time tc of the clutch pedal 11 is calculated based on the depression speed v of the clutch pedal 11 (depression completion time estimation step ST61). For example, the time when the clutch flag is turned on and the depression speed v of the clutch pedal 11 are used, and it is assumed that the depression of the clutch pedal 11 is completed while the depression speed v of the clutch pedal 11 is constant. The tread completion time tc is estimated. After step ST61, the process proceeds to step ST62.

  In step ST62, the restart start time ts of the engine 2 is calculated based on the estimated value of the depression completion time tc of the clutch pedal 11. For example, in this embodiment, since the time from the restart start time ts of the engine 2 to the restart completion time te of the engine 2 (energization time of the starter 22) ΔTs is constant, the restart start time of the engine 2 ts is calculated by calculating back from the estimated value of the depression time tc of the depression of the clutch pedal 11.

  Then, the restart of the engine 2 is started based on the restart start time ts of the engine 2 (step ST8).

  In this modification, since the restart start time ts of the engine 2 is calculated based on the estimated value of the depression completion time tc of the clutch pedal 11, the engine restart start time is uniquely defined using a predetermined control map. Compared with the structure to perform, the difference (DELTA) Ti = te-tc of the restart completion time te of the engine 2 and the depression completion time tc of the clutch pedal 11 can be controlled more accurately. Thereby, the useless idling time ΔTi can be further shortened, so that the fuel consumption of the engine 2 is reduced.

  5 and 6 are timing charts showing an embodiment of the vehicle drive system shown in FIG.

  In FIG. 5, in the conventional example, when the engine is restarted during eco-running, the starter is energized simultaneously with the start of depression of the clutch pedal and the engine is restarted (see FIGS. 5A and 5C). ). For this reason, there is a useless idling time ΔTi ′ from the engine restart completion time te ′ to the clutch pedal depression completion time tc (see FIG. 5D).

  On the other hand, in the first embodiment of the vehicle drive system 1, control for changing the restart start time ts of the engine 2 according to the depression speed v of the clutch pedal 11 is performed. Thereby, useless idling time ΔTi is ΔTi = 0 (see FIG. 5D). Hereinafter, this control will be described (see FIGS. 2 and 5).

  First, when the operation of depressing the clutch pedal 11 is performed while the engine 2 is stopped and in a restart standby state, the clutch flag is turned on (see FIGS. 5A and 5B). Then, the restart condition of the engine 2 is established (affirmative determination in step ST1), and the internal time t of the control unit 5 is reset to t = 0 (step ST2).

  Next, the depression amount x (see FIG. 5B) of the clutch pedal 11 is acquired at a predetermined sampling interval (step ST3), and the depression speed v of the clutch pedal 11 is calculated based on the depression amount x (step ST3). Step ST4).

  Next, the restart start time ts of the engine 2 is calculated based on the depression speed v of the clutch pedal 11 (step ST6). The restart start time ts is a time at which the restart completion time te of the engine 2 is simultaneously (or immediately before) the depression completion time tc of the clutch pedal 11, and is a predetermined control map (see FIG. 3) or a predetermined Is calculated based on the control flow (see FIG. 4). For example, in the first embodiment shown in FIG. 5, the restart completion time te of the engine 2 and the depression completion time tc of the clutch pedal 11 are the same time. Thereby, useless idling time ΔTi is omitted.

  Next, when the restart start time ts of the engine 2 is reached, energization of the starter 22 is started and restart of the engine 2 is started (affirmative determination in step ST7 and step ST8) (see FIG. 5C). . Then, when the rotation speed of the engine 2 rises and the restart of the engine 2 is completed (t = te), the depression of the clutch pedal 11 is completed and the shift position is changed (FIG. 5B and FIG. 5). (See (d)). Note that energization of the starter 22 is interrupted when the restart of the engine 2 is completed (see FIG. 5C).

  Further, in FIG. 6, the second embodiment shows a case where the depression speed v of the clutch pedal 11 is faster than the first embodiment (see FIG. 6B). In the second embodiment, the standby time ΔTw2 from the depression start time t2 = 0 of the clutch pedal 11 to the restart start time ts of the engine 2 is shorter than the standby time ΔTw1 of the first embodiment. Thereby, the restart completion time te of the engine 2 is controlled so as to be simultaneous (or immediately before) the depression completion time tc of the clutch pedal 11. The time ΔTs required for starting the engine 2 is the same in both cases of the first and second embodiments (see FIG. 6C).

  If the depression speed v of the clutch pedal 11 is equal to or higher than the predetermined threshold value k, the engine 2 is immediately restarted (Yes determination in step ST5 and step ST8). Thereby, the engine start delay is prevented.

[effect]
As described above, in the vehicle drive system 1, when the engine 2 is stopped and is in a standby state for restart, the engine 2 is restarted with the depression operation of the clutch pedal 11 as a condition (affirmative determination in step ST <b> 1). Control for starting is performed (step ST8) (see FIGS. 2 and 5). At this time, the restart start time ts of the engine 2 is changed according to the depression speed v of the clutch pedal 11 (step ST3 and step ST6).

  In such a configuration, the relationship between the time te at which the restart of the engine 2 is completed and the idling state is completed and the time tc at which the depression of the clutch pedal 11 is completed and the shift position can be changed can be adjusted. Thereby, there exists an advantage which can perform restart control of the engine 2 according to a driver | operator's characteristic (depression speed v of the clutch pedal 11). For example, when the depression speed v of the clutch pedal 11 is high, the control for shortening the idling time ΔTi can be performed. Therefore, there is an advantage that the fuel consumption of the vehicle can be reduced and the fuel consumption can be improved. In the configuration in which the starter is driven and the engine is restarted simultaneously with the start of depression of the clutch pedal 11 (see the conventional example in FIG. 5), from the engine restart completion time te ′ to the clutch pedal 11 depression completion time tc. Is not preferable because the idling time ΔTi ′ changes due to variations in the depression speed of the clutch pedal 11.

  In the vehicle drive system 1, control is performed such that the restart start time ts of the engine 2 is delayed as the depression speed v of the clutch pedal 11 is slower (see FIGS. 3 and 6). In such a configuration, since the waiting time ΔTi from the restart completion time te of the engine 2 to the depression completion time tc of the clutch pedal 11 can be shortened, there is an advantage that fuel consumption can be reduced and fuel consumption can be improved.

  Further, the vehicle drive system 1 detects a depression amount x of the clutch pedal 11 (clutch stroke amount sensor 522) and calculates a depression speed v of the clutch pedal 11 from the depression amount x of the clutch pedal 11 ( A stepping speed calculation unit 512), a predetermined control map (see FIG. 3) that defines the relationship between the stepping speed v of the clutch pedal 11 and the restart start time ts (standby time ΔTw) of the engine 2, and based on this control map Means for calculating the restart start time ts of the engine 2 (restart start time calculating unit 513) (see FIGS. 1 and 2). In such a configuration, the restart start time ts of the engine 2 can be uniquely calculated by using a predetermined control map (step ST6). As a result, the restart start time ts can be easily calculated, and the configuration of the control unit 5 can be simplified.

  Further, the vehicle drive system 1 detects a depression amount x of the clutch pedal 11 (clutch stroke amount sensor 522) and calculates a depression speed v of the clutch pedal 11 from the depression amount x of the clutch pedal 11 ( A stepping speed calculation unit 512), means for estimating the depression time tc of the clutch pedal 11 based on the depression speed v of the clutch pedal 11 (depression completion time estimation unit 514), an estimated value of the depression completion time tc, and the engine 2 Means (restart start time calculation unit 513) for calculating the restart start time ts of the engine 2 based on the time ΔTs required for the restart (see FIGS. 1, 2 and 4). In such a configuration, since the restart start time ts of the engine 2 is calculated based on the estimated value of the depression completion time tc of the clutch pedal 11, the restart completion time te of the engine 2 and the depression completion time tc of the clutch pedal 11 are calculated. The difference ΔTi (= te−tc) can be controlled with higher accuracy. Thereby, the useless idling time ΔTi can be further shortened, and there is an advantage that the fuel consumption of the engine 2 can be further reduced.

  In addition, the vehicle drive system 1 is preferably applied to an eco-run vehicle that utilizes free-run (inertial travel). In such an eco-run vehicle, the restart control of the engine 2 is performed more frequently than an eco-run vehicle that only performs idling stop control when the vehicle stops at an intersection. Therefore, since the fuel consumption accompanying the restart control of the engine 2 can be reduced, there is an advantage that the fuel consumption can be further improved.

  As described above, the vehicle drive system according to the present invention is useful in that the engine restart control can be performed in accordance with the characteristics of the driver.

1 vehicle drive system, 2 engine, 21 output shaft, 22 starter, 3 clutch mechanism, 4 transmission, 41 input shaft, 42 output shaft, 5 control unit, 511 eco-run control unit, 512 stepping speed calculation unit, 513 restart Start time calculation unit, 514 Depression completion time estimation unit, 515 storage unit, 521 clutch pedal sensor, 522 clutch stroke amount sensor, 523 shift position sensor, 6 battery, 7 compressor drive motor, 8 alternator, 9 voltage stabilization circuit, 10 wheels, 11 clutch pedal, 12 shift lever device

Claims (1)

A vehicle drive system that performs control to restart an engine on condition of a depression operation of a clutch pedal when the engine is stopped and in a standby state for restart,
A vehicle drive system comprising means for calculating an engine restart start time according to a depression speed of a clutch pedal.

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