JP2012172637A - Control device of idle reduction vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the fuel economy while preventing an engine from being carelessly restarted even when a driver temporarily changes his or her posture during the idle reduction, and allowing the engine to be rapidly restarted according to the intention of the driver when the driver returns his or her driving posture.SOLUTION: A determination means of an idle reduction control part 11 determines whether the driving posture condition (release of a seat belt or the like) that the driving posture of a driver is changed. When the determination means determines that the driving posture condition is established during the idle reduction, a restart control means of the idle reduction control part 11 prohibits the restart of an engine 3 caused by the change of the driving posture, and accordingly, by the drop of the braking force based on the step-on of a brake pedal 21 below the predetermined value, preventing careless restart of the engine 3, and an alarm is given during the release of a seat belt. When a driver operates the accelerator pedal, and shows the intention of the start, the accelerator pedal is operated, the engine 3 is restarted, and an idle reduction vehicle 1 is started.

Description

  The present invention relates to a control device for an idle stop vehicle. More specifically, the present invention relates to the establishment of an engine restart condition including at least one of a brake force based on depression of a brake pedal being equal to or less than a predetermined value and an accelerator pedal being operated. Relates to restarting the engine.

  In general, when an eco-run system (idle stop system) is turned on by turning on an ignition (IG) key or an IG switch, an idle stop vehicle is stopped by idling the engine by a predetermined engine automatic stop condition. During the idling stop, the engine is repeatedly restarted when a predetermined engine restart condition is satisfied because the brake force is reduced below a predetermined level by depressing the brake pedal or the accelerator pedal is operated.

  An example of the automatic engine stop condition is that the engine hood switch is turned on (closed), the door seat switch or door on the driver seat is turned on (closed), the shift position is in the D range, the battery voltage is higher than the predetermined voltage, etc. In the idle stop standby state where the conditions are cleared, at least the vehicle speed is 0 km / h (stop), and the braking force of the master cylinder pressure is, for example, 0.7 MPa or more.

  An example of the engine restart condition by the driver operation is that the master cylinder pressure is reduced to, for example, 0.10 MPa when the driver loosens the foot from the brake pedal at least in an idle stop state, or the driver depresses the accelerator pedal. The accelerator opening is, for example, 1% or more. If the battery voltage drops below the specified voltage or the air conditioner is operated during idle stop, the engine will automatically restart regardless of the engine restart conditions to prevent battery discharge. It is started.

  In such an idle stop vehicle, when the driver leaves the vehicle and forgets to turn off the IG key or IG switch during the idle stop, the detection of the release of the seat belt and the weight change of the weight sensor Based on the detection or the like, it is proposed to detect the driver's leaving operation, execute the engine stall mode, stop the engine, and forcibly release (turn off) the eco-run system (for example, Patent Document 1 (paragraph) [0039], [0040], FIG. 1, FIG. 2, etc.)).

JP-A-2005-207327

  In this kind of idle stop car, during the idle stop, for example, when the driver twists the upper body to take the back seat luggage and the driver's driving posture temporarily collapses, based on the collapse of the posture, There is a possibility that the driver will weaken the brake pedal and the engine restart condition (brake force based on the brake pedal depression is below a certain level) will be met, and the engine will be inadvertently restarted. .

  In this case, in order to prevent inadvertent start of the engine, as described in Patent Document 1, the driver's leaving operation is detected, the engine stall mode is executed, the engine is stopped, and the eco-run system is forced. For example, when a driver who breaks the driving posture and picks up the luggage in the rear seat returns to the original position, the eco-run system has already been released and is not in the idle stop state. After that, to start the engine, it is necessary to turn on the IG key or IG switch again, and it is difficult for the driver to start and start quickly as in the case of engine restart during idle stop. In addition to making you feel, fuel economy decreases if you turn on the IG key or IG switch again early to prepare for starting .

  The present invention prevents the engine from being inadvertently restarted and started even if the driver temporarily loses the driving posture during idle stop, and promptly changes the engine according to the driver's intention when returning to the driving posture. The purpose is to improve fuel efficiency by allowing the vehicle to restart and start.

  In order to achieve the above-described object, the control device for an idle stop vehicle according to the present invention stops the engine by idling when a predetermined engine automatic stop condition is satisfied, and performs braking based on depression of the brake pedal during the idle stop. A control device for an idle stop vehicle that restarts the engine upon establishment of an engine restart condition that includes at least one of a reduction in force below a predetermined value and an operation of an accelerator pedal. Based on the depression of the brake pedal when the determination unit determines whether or not the driving posture condition that is collapsed is satisfied, and the determination unit determines that the driving posture condition is satisfied during idle stop Prohibiting restart of the engine due to a decrease in braking force below a predetermined value, Kuserupedaru is characterized in that has a restart control means to restart the Nisato the engine to be operated (claim 1).

  According to the present invention as set forth in claim 1, during the idle stop, for example, the driver's driving posture is temporarily collapsed by twisting the upper body in order to take the luggage of the rear seat, and the determination means that the driving posture condition is satisfied. If determined, the restart control means prohibits restart of the engine due to a decrease in the braking force based on depression of the brake pedal to a predetermined value or less. Therefore, even if the driver temporarily loses the driving posture during idling stop and the brake pedal is weakened by the driver, the engine will not restart, and the engine is inadvertently restarted during idling stop. There is no start.

  In addition, even if the judgment means judges that the driving posture is temporarily satisfied and the driving posture condition is satisfied during the idling stop, the eco-run system is not canceled depending on this judgment, and the driver returns to the original posture. Sometimes the idle stop state continues, and when the driver indicates the intention to start by operating the accelerator pedal, the restart control means will promptly operate the engine without turning on the IG key or IG switch again. You can start by restarting. In this case, since the engine is stopped by idle stop until the driver operates the accelerator pedal and indicates the intention to start, fuel efficiency is improved.

  Therefore, even if the driver temporarily loses the driving posture during idle stop, the engine will not be inadvertently restarted and start, and when the driving posture is returned, the engine is quickly restarted according to the driver's intention. Fuel consumption can be improved by starting and starting.

It is a block diagram of one embodiment of a control device of an idle stop car of the present invention. 2 is a timing chart for explaining the operation of FIG. 1. It is a flowchart for operation | movement description of FIG.

  Next, in order to describe the present invention in more detail, an embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 shows a block configuration of a control device for an idle stop vehicle 1. The idle stop vehicle 1 includes a single lead battery 2 having a relatively small capacity of 12 V as a power source in order to reduce weight, size, and the like. The negative terminal of the lead battery 2 is connected to the housing of the idle stop vehicle 1.

  3 is an engine of the idle stop vehicle 1, and 4 is a CVT on the transmission side of the engine 3, and a torque converter (including a lock-up clutch mechanism) 5 is interposed between the engine 3 and the engine 3.

  Reference numeral 6 denotes a starter for starting the engine 3, and power is supplied from the lead battery 2 through the relay 7. A battery sensor 8 is provided close to the lead battery 2 between the positive terminal of the lead battery 2 and the relay 7, and detects the temperature and current of the lead battery 2. Reference numeral 9 denotes an alternator to which the rotational force of the engine 3 is transmitted via the belt 10 and charges the lead battery 2 with a power generation output during traveling.

  11 is an idle stop control unit formed by an idle stop control ECU, 12 is an engine control unit formed by an engine control ECU, 13 is an ABS control unit formed by an ABS (antilocked breaking system) control ECU, and 14 is CVT control. The control units 11 to 14 are each formed by a microcomputer or the like, and exchange information via a communication bus 15 such as a CAN.

  Reference numeral 16 denotes a display / alarm unit formed by a dashboard combination meter or the like. The display / alarm unit 16 receives various display data from the communication bus 15 to display the vehicle speed and the like. An alarm is received and a lamp is lit or a buzzer sounds.

  Reference numeral 17 denotes a driving posture detection unit connected to the idle stop control unit 11, for example, a winding sensor or driver for detecting the amount and speed of the seat belt withdrawing / winding of the driver seat in order to detect the driving posture of the driver. It consists of a seat belt sensor that detects whether the seat belt is worn or not, a seating sensor that detects pressure on each part of the driver's seat by changes in resistance or voltage, etc. It also includes a camera for shooting.

  Then, the determination means of the idle stop control unit 12 detects and monitors the driving posture of the driver, detects the state (amount and speed) of the driver seat's seat belt withdrawing / rewinding by the driving posture detection unit 17, and seat belt wearing It is determined whether or not the driving posture condition that the driving posture is broken is satisfied from the detection of the state / non-wearing state, the detection of the sitting state, and the photographed image of the driver every moment. Specifically, for example, when the driver twists the upper body to pick up the luggage in the rear seat, the seat belt is pulled out more than a predetermined amount, the seating state is biased to the right or left, the camera's captured image When the driver in the vehicle changes from a front image to a landscape image or a backward image, the determination means, for example, determines a change in the driver's driving posture over a threshold value from a majority decision process that weights these state change amounts. It is determined that the driving posture condition is satisfied. Further, it is determined that the driving posture condition is satisfied even when the seat belt is not worn. While the driving posture condition is satisfied during the idle stop, based on the determination by the determining unit, the alarm control unit of the idle stop control unit 12 displays the driving posture condition on the display / alarm unit 16 via the communication bus 15, for example. Is issued, the display / alarm unit 16 is informed of the establishment of the driving posture condition, and the driver is alerted. In this case, it can also play a role of notifying the driver that the vehicle is idling.

  1, 18 is a wheel speed sensor that provides vehicle speed detection information to the ABS control unit 13, and 19 is a hydraulic pressure sensor that provides master cylinder pressure (M / C pressure) detection information of the brake mechanism 20 to the ABS control unit 13. .

  The brake mechanism 20 is a well-known hydraulic brake booster mechanism, and the depression force of the brake pedal 21 is used to assist the braking force in the inlet manifold of the engine 3 by a brake booster (vacuum booster) 22 including a negative pressure sensor. It is amplified using negative pressure and applied as a braking force to the wheel cylinder 24 of each wheel 23 of the idle stop vehicle 1 via the master cylinder 25, the hydraulic pressure sensor 19 and the like.

  The general control and operation of the idle stop vehicle 1 will be described. The driver turns on an IG key or an IG switch (not shown), and the eco-run system (idle stop system) of the configuration of the idle stop vehicle 1 shown in FIG. Is turned on and an engine start command is issued, for example, an IG ON signal is input from the communication bus 15 to the idle stop control unit 11. Based on this input, the idle stop control unit 11 instantaneously energizes the relay 7 and turns on. Then, the power source of the lead battery 2 is supplied to the starter 6 to start the starter 6, and the engine 3 that has been stopped is started (initial start). Once the engine 3 is started and the lead battery 2 is fully charged with the power generated by the alternator 9, the idle stop control is performed until the engine 3 is stopped by turning off the IG key or the IG switch. The automatic stop control means and the restart control means of the section 11 execute idle stop control, and repeats the automatic stop of the engine 3 when the engine automatic stop condition is satisfied and the automatic restart when the engine restart condition is satisfied.

  The idle stop control unit 11 is connected to the engine 3 such as the engine speed, the coolant temperature, the negative pressure, the throttle opening degree, the voltage of the lead battery 2, Information such as current and temperature, information such as the detected vehicle speed of the wheel speed sensor 18 acquired by the ABS control unit 13, master cylinder pressure of the hydraulic pressure sensor 19, lock-up clutch information of the CVT control unit 14, stop not shown Information on switches in various parts of the vehicle such as lamp switches and courtesy switches is input. Further, the IG-ON signal of the starter 6 and the detection information of the driving posture of the driving posture detection unit 17 are also input to the idle stop control unit 11.

  When the driver depresses the brake pedal in accordance with a red signal of the traffic signal and the master cylinder pressure exceeds a predetermined depressing pressure (for example, 0.7 MPa), the stop control means of the idle stop control unit 11 performs automatic engine stop. Conditions (for example, the engine hood switch is on (closed), the driver seat side door courtesy switch or door is on (closed), the shift position is in the D range, and the negative pressure of the brake booster 22 is on the vacuum side above a predetermined threshold. That the battery voltage is equal to or higher than a predetermined voltage, the vehicle speed is 0 km / h (stop), and the master cylinder pressure is 0.7 MPa or higher, for example), the idle stop control unit 11 causes the engine control unit 12 to An automatic stop request is output, and the engine control unit 12 throttles the fuel throttle based on this request. To automatically stop the engine 3.

  In order to further improve the fuel efficiency, the engine automatic stop condition is satisfied by lowering the vehicle speed to a predetermined vehicle speed (for example, 7 km / h) or less while the driving of the idle stop vehicle 1 is not completely stopped. Then, the engine 3 may be automatically stopped.

  Further, the idle stop control unit 11 requests the ABS control unit 13 to apply an automatic brake of the brake mechanism 20, and based on this request, the brake mechanism 20 applies a braking force (brake hydraulic pressure) immediately before stopping traveling to the wheel cylinder 24. Hold.

  Next, the driver removes his / her foot from the brake pedal 21 due to the traffic signal changing to a green light, etc., and the master cylinder pressure drops to a predetermined opening pressure (for example, 0.10 MPa) or the driver depresses the accelerator pedal to open the accelerator. For example, when the predetermined engine restart condition is established by a driver operation or the like when the degree becomes 1% or more, the restart control means of the idle stop control unit 11 confirms that the engine restart condition is satisfied, thereby A restart request is generated, and based on this request, the idle stop control unit 11 is turned on by instantaneously energizing the relay 7, the power of the lead battery 2 is supplied to the starter 6, and the starter 6 is started and stopped. The engine 3 is automatically restarted. When the engine 3 is restarted, an automatic brake release request from the idle stop control unit 11 is sent to the ABS control unit 13, and the braking force held in the wheel cylinder 24 is released based on this request. Note that when the battery voltage drops below a predetermined voltage or the air conditioner is operated during idle stop, the restart control means of the idle stop control unit 11 prevents the battery 2 from discharging. The engine 3 is automatically restarted regardless of the engine restart condition. In addition, when the negative pressure detected by the negative pressure sensor that detects the negative pressure of the brake booster is on the atmospheric pressure side from the predetermined threshold value, the automatic operation is performed in the same manner as described above in order to secure the negative pressure. The engine 3 is restarted.

  By the way, during idling stop, for example, when the driver twists the upper body in order to take the luggage of the rear seat and the driving posture of the driver is temporarily collapsed, the idling stop control unit based on the detection information of the driving posture detection unit 17 Twelve determination means determine that the driving posture condition is satisfied. In this case, the idle stop control unit 11 does not release the eco-run system by continuing the idle stop control, but the restart control means reduces the master cylinder pressure to the predetermined release pressure based on the depression of the brake pedal 21. Therefore, restart of the engine 3 is prohibited.

  Therefore, even if the driver temporarily loses his driving posture during idling stop and the driver depresses the brake pedal 21, the engine restart condition is not satisfied, and the engine 3 is restarted. This prevents the engine 3 from being inadvertently restarted during an idle stop. Further, since the alarm is issued as described above when the driving posture of the driver is temporarily lost during the idle stop, it is possible to notify the situation where the restart of the engine by the operation of the brake pedal 21 is prohibited. Thereby, it is possible to prevent the driver from being worried that the engine is not restarted by operating the brake pedal 21.

  When the driver returns to the original position, the idle stop state continues.After that, when the driver indicates the intention to start by operating the accelerator pedal, the engine restart condition is determined based on the operation of the accelerator pedal. Thus, the restart control means can quickly restart the engine 3 and start without performing the operation of turning on the front IG key or the IG switch again. In this case, since the engine 3 is stopped by idle stop until the driver operates the accelerator pedal and indicates the intention to start, fuel efficiency is improved. It should be noted that the driver's accelerator pedal operation that satisfies the engine restart condition is preferably started when the driver's driving posture is lost or the driver accidentally steps on the accelerator pedal when returning to the original position. In order to exclude from the intention display, for example, the operation may be limited to an operation in which the accelerator opening (accelerator pedal depression speed) changes at a moderate speed equal to or lower than the set speed. That is, the restart control means may restart the engine when the accelerator pedal depression speed is equal to or lower than a predetermined set speed.

  Steps S1 to S9 in FIG. 2 show an example of the above-described idle stop control procedure. After the IG-ON operation, the engine automatic stop condition is awaited (NO in step S1), and the engine automatic stop condition is satisfied (step S1). YES), an engine automatic stop request is generated, the engine 3 is automatically stopped, and the idle stop vehicle 1 is idle stopped with the driver stepping on the brake pedal 21 (step S2). At this time, for example, the brake force (brake hydraulic pressure) immediately before the stop of traveling is held in the wheel cylinder 24 based on the automatic brake application request, and the idle stop vehicle 1 is held in the hill hold (hill start) automatic brake state ( Step S3).

  Next, when the brake force of the master cylinder pressure based on the depression of the brake pedal 21 is reduced to a predetermined release pressure (for example, 0.10 MPa) or the accelerator pedal is operated, the engine restart condition is satisfied, or When the battery voltage drops below a predetermined voltage or when the air conditioner is operated, the engine restart condition based on the automatic restart request of the engine 3 is awaited (NO in step S4). When the start condition is satisfied (YES in step S4), it is first determined whether or not the driving posture condition is satisfied (step S5).

  Then, normally, the driving posture of the driver is not broken, and the driving posture condition is not satisfied, and step S5 is NO and the process proceeds to step S6. At this time, the engine 3 is restarted by the engine restart request (step S6), and the brake pressure of the wheel cylinder 24 is released by the automatic brake release request to release the automatic brake, and the idle stop vehicle 1 starts running. It becomes possible (step S7).

  On the other hand, when the driving posture of the driver is broken in step S5, the driving posture condition is satisfied, and step S5 is passed through YES and the process proceeds to step S8.

  At this time, if the brake force of the master cylinder pressure is not reduced to a predetermined release pressure (for example, 0.10 MPa), the battery voltage is reduced to a predetermined voltage or lower, or the air conditioner is operated automatically. It is determined that the engine restart condition is satisfied based on the restart request of the engine 3 (NO in step S8), the engine 3 is restarted by the engine restart request (step S6), and the automatic brake In response to the release request, the brake pressure of the wheel cylinder 24 is released and the automatic brake is released (step S7). Here, even if the automatic brake is released, since the braking force of the master cylinder pressure is large, the idle stop vehicle 1 remains stopped in the idling state.

  If the brake force of the master cylinder pressure is reduced to a predetermined release pressure (for example, 0.10 MPa) when YES is passed through step S5 and the process proceeds to step S8, the brake pedal is disengaged due to the collapse of the driving posture of the driver. Since there is a high possibility that it has been loosened, step S8 is passed through YES and the process proceeds to step S9. At this time, even if the brake force of the master cylinder pressure based on the depression of the brake pedal 21 is reduced to a predetermined release pressure (for example, 0.10 MPa), restart of the engine 3 due to this is prohibited, so from step S8 The process proceeds to step S9 and waits for the accelerator pedal to be operated (NO in step S9). When the accelerator pedal is operated and turned on (YES in step S9), the engine 3 is restarted by an engine restart request (step S9). S6) Further, the brake pressure of the wheel cylinder 24 is gradually released by the automatic brake release request, the automatic brake is released, and the idle stop vehicle 1 starts running (step S7).

  FIG. 3 is a timing chart showing an example of a state change such as the vehicle speed of the idle stop vehicle 1 during the period from the idle stop by the above-described idle stop control to the stop of the engine restart, where (a) is the vehicle speed and (b) is the master. Cylinder pressure, (c) engine speed, (d) seat belt on / off, (e) idling stop (on) period, (f) accelerator pedal on / off, (g) Indicates wheel cylinder pressure. In addition, (d) shows that the wearing state of the seat belt is on and the non-wearing state is off. That is, OFF indicates that the driving posture condition is satisfied, and the seat belt ON / OFF is an example here.

  If the driver switches from the accelerator pedal to the brake pedal 21 at time t1 in FIG. 3, for example, based on a red signal ahead while the idle stop vehicle 1 is traveling, the master cylinder pressure increases and the vehicle speed and engine rotation decrease.

  Then, the engine automatic stop condition includes that the master cylinder pressure has reached a predetermined depression pressure (0.7 MPa in this case) at t2 in FIG. 3 and that the vehicle speed has become zero and the traveling of the idle stop vehicle 1 has stopped. As a result, the idle stop vehicle 1 enters an idle stop state (idle stop on).

  Next, during idling stop, when the driver's driving posture collapses at t3 in FIG. 3 and the seat belt is released (when the seat belt is not put on), the determination means of the idling stop control unit 12 determines that the driving posture condition is satisfied. to decide.

  Furthermore, the depression of the brake pedal 21 by the driver is weakened due to the collapse of the driving posture at t4 in FIG. 3 during idling stop, and the master cylinder pressure is reduced to a predetermined opening pressure (here, 0.10 MPa) at t5 in FIG. However, even if the driver's driving posture returns at t6 in the figure, the idle stop vehicle 1 is maintained in the idle stop state until t7 in the figure in which the accelerator pedal is depressed. Note that τ in FIG. 3 is a period during which the restart of the engine 3 is prohibited because the driving posture condition is satisfied.

  When the accelerator pedal is depressed at t7 and the engine restart condition is satisfied, the engine 3 is restarted and the rotational speed of the engine 3 is increased, and the braking force of the wheel cylinder 14 is gradually released, and the hill hold ( Or, the hill start start) prevents the vehicle from sliding down on a slope or the like, and the idle stop vehicle 1 starts.

  As described above, in the case of the present embodiment, during the idle stop of the idle stop vehicle 1, for example, the driver's driving posture is temporarily collapsed by twisting the upper body in order to take the luggage of the rear seat, and the driving posture condition is When the determination unit of the idle stop control unit 11 determines that the condition is established, the restart control unit of the idle stop control unit 11 restarts the engine 3 due to the brake force based on the depression of the brake pedal 21 being reduced below a predetermined level. Ban. Therefore, even if the driver temporarily loses the driving posture during idle stop and the brake pedal is weakened by the driver, the engine 3 is not restarted, and the engine 3 is inadvertently restarted during idle stop. And will not start.

  Even if the determination means determines that the driving posture is temporarily satisfied during the idling stop and the driving posture condition is satisfied, the eco-run system of the idling stop vehicle 1 is not released depending on this determination, and the idling stop is performed. Therefore, when the driver returns to his original position, the idle stop state will continue.After that, when the driver indicates the intention to start by operating the accelerator pedal, the IG key or IG switch The restart control means can quickly restart the engine 3 and start the idle stop vehicle 1 without performing an on operation again.

  In this case, since the engine 3 is stopped by idle stop until the driver operates the accelerator pedal and indicates the intention to start, fuel efficiency is improved.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. The control means may be provided in another control unit or the like of the idle stop vehicle 1. Further, the aforementioned braking force is not limited to the brake fluid pressure, and may be the amount of depression of the brake pedal as long as the braking force (braking degree) can be determined.

  Further, the engine automatic stop condition and the engine restart condition may be different from those in the above embodiment.

  Furthermore, it is needless to say that the configuration of the control device for the idle stop vehicle 1 may be different from that shown in FIG.

  The present invention can be applied to idle stop control of various idle stop vehicles including at least an engine as a driving force source.

DESCRIPTION OF SYMBOLS 1 Idle stop vehicle 3 Engine 11 Idle stop control part 19 Fluid pressure sensor 21 Brake pedal 25 Master cylinder 24 Wheel cylinder

Claims (1)

When the predetermined engine automatic stop condition is satisfied, the engine is stopped and idle stopped, and at the time of idling stop, at least one of the brake force based on the depression of the brake pedal decreases below a predetermined level and the accelerator pedal is operated. A control device for an idle stop vehicle that restarts the engine when an engine restart condition including
A determination means for determining whether or not a driving posture condition is satisfied, which is that the driving posture of the driver is broken;
When the determination means determines that the driving posture condition is satisfied during idle stop, the engine is prohibited from restarting due to a brake force based on depression of the brake pedal being reduced to a predetermined value or less. A control device for an idle stop vehicle, comprising: restart control means for restarting the engine when an accelerator pedal is operated.

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