JP2013087723A - Idling stop control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strike a balance between the avoidance of a failure in automatic restart and the increase of an opportunity of automatic stop.SOLUTION: An idling stop control device is applied to a vehicle being capable of performing motor start, where an engine is started by the driving force of a starter motor, and kick start, where the engine is started by human power of a driver, and including an idling stop function. Here, when the driver performs kick start, it means that the driver determines that motor start cannot be executed. The idling stop control device is then characterized by comprising: a kick start determination means S10 which determines whether or not kick start is executed; and an idling stop inhibition control means S14 which inhibits idling stop even if idling stop conditions are satisfied, after the execution of kick start is determined. Thus, automatic stop is inhibited based on the driver's determination that motor start cannot be executed, thereby reducing the risk of automatic restart failure without reducing the opportunity of automatic stop beyond necessity.

Description

  The present invention relates to an idle stop control device applied to a vehicle capable of motor start and kick start.

  In a vehicle with an idle stop function that automatically stops the engine and then restarts automatically, if the battery is deteriorated, the driving force of the starter motor becomes insufficient and the piston cannot get over the compression stroke of the engine. There is a concern that the automatic restart may fail.

  Therefore, conventionally, automatic stop by the idle stop function is prohibited when the remaining battery capacity is smaller than the determination threshold (see Patent Document 1). As the determination threshold is set higher, the risk of failing in automatic restart can be reduced, but the chance of automatic stop is reduced as a contradiction, and fuel efficiency cannot be sufficiently improved. Therefore, it is important to set the determination threshold value to an optimum value in order to achieve both the avoidance of failure of automatic restart and the increase of opportunities for automatic stop.

  However, whether or not the piston gets over the compression stroke (whether or not the restart fails) is influenced by various factors such as the temperature of engine lubricating oil and the engine displacement in addition to the remaining battery capacity. Therefore, it is extremely difficult to set a determination threshold value so that the above-described compatibility can be realized.

JP 2004-353474 A

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an idle stop control device that achieves both avoidance of failure of automatic restart and increase of opportunities for automatic stop.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  According to the first aspect of the present invention, motor start for starting the engine by the driving force of the starter motor and kick start for starting the engine by the driver's human power are possible, and a predetermined idle stop condition is satisfied. It is assumed that the engine is sometimes automatically stopped and applied to a vehicle having an idle stop function that automatically restarts the engine by starting the motor when a predetermined start condition is satisfied.

  And a kick start determining means for determining whether or not the kick start has been executed, and after the execution of the kick start is determined, the automatic stop is performed even when the idle stop condition is satisfied. And an idle stop prohibiting control means for prohibiting.

  The present inventors recalled the above invention based on the following findings. In other words, when the driver starts kicking, the motor has failed to start despite having recognized that the battery has deteriorated before the start of vehicle operation or operating the starter switch to start the motor. Cases are assumed. That is, if the driver has kick-started, it can be said that the driver has determined that the motor cannot be started.

  In the above invention recalled based on this knowledge, after it is determined that kick start has been executed, automatic stop is prohibited even when the idle stop condition is satisfied. Therefore, since the automatic stop is prohibited based on the determination by the driver that the motor cannot be started, the risk of the automatic restart failure can be automatically reduced without reducing the opportunity for the automatic stop more than necessary.

  In the invention according to claim 2, when it is determined that the kick start has been executed, the kick start is executed within a predetermined time after the automatic restart has failed. The automatic stop is prohibited by idle stop prohibition control means.

  Depending on the driver, even if the battery has not deteriorated and the motor can be started sufficiently, the kick start may be executed. Prohibiting automatic stop even in this case decreases compatibility between avoiding automatic restart failure and increasing opportunities for automatic stop. In the above invention in view of this point, since automatic stop is prohibited on condition that kick start is executed within a predetermined time after failure of automatic restart, automatic restart by the idle stop function has failed. Accordingly, when the driver starts kicking, automatic stop can be prohibited, and compatibility between avoiding failure of automatic restart and increasing opportunities for automatic stop can be improved.

  By the way, when the starter motor is energized and the N signal described later is not input for a predetermined time of n seconds or longer, or the starter motor is energized and turned on, What is necessary is just to determine with the said "automatic restart failure", when the state where speed does not become more than predetermined rotation speed xrpm continues for the predetermined time n second or more.

  In addition, when such a determination of “failure of automatic restart” is established, the timer starts counting, and when kick start is executed during the period until the timer reaches a certain value, It may be determined that the kick start has been executed within a predetermined time after the failure.

  According to a third aspect of the present invention, the vehicle is configured such that the motor start is performed when a starter switch is operated by a driver, and when it is determined that the kick start is performed, the kick is performed. The automatic stop is prohibited by the idle stop prohibition control means on condition that the start is executed within a predetermined time after the starter switch is operated.

  Depending on the driver, even if the battery has not deteriorated and the motor can be started sufficiently, the kick start may be executed. Prohibiting automatic stop even in this case decreases compatibility between avoiding automatic restart failure and increasing opportunities for automatic stop. In the above-mentioned invention in view of this point, the automatic stop is prohibited on the condition that the kick start is executed within a predetermined time after the starter switch is operated. In this case, automatic stop can be prohibited, and compatibility between avoiding automatic restart failure and increasing opportunities for automatic stop can be improved.

  According to a fourth aspect of the present invention, there is provided a return determination means for determining whether or not a storage amount of a battery that supplies power to the starter motor has returned to a predetermined amount or more, and after determining that the kick start has been executed. When it is determined that the return is determined by the return determination means, the automatic stop prohibition by the idle stop prohibition control means is canceled.

  According to this, after the automatic stop is prohibited by the idle stop prohibition control means, when the remaining capacity of the battery has increased, or when the battery has been replaced with a new battery, there is no risk of the automatic restart failure. The automatic stop prohibition is canceled when returning to. Therefore, even after the battery is restored, compatibility between avoiding automatic restart failure and increasing opportunities for automatic stop can be improved.

  A specific example of the return determination by the return determination unit will be described below. That is, when the engine is continuously operated for a certain period or longer, it is determined that the remaining battery capacity has increased sufficiently and the return determination is made. Alternatively, when the state in which the battery voltage has become equal to or higher than a predetermined value continues for a predetermined time or longer while the vehicle is traveling, it is determined that the remaining battery capacity has increased sufficiently and the return determination is made.

The figure which shows the engine system with which the idle stop control apparatus concerning 1st Embodiment is applied. The flowchart which shows the control procedure of an idle stop function in 1st Embodiment. The time chart which shows the various changes at the time of motor starting. A time chart showing various changes at the time of kick start. The flowchart which shows the control procedure of an idle stop function in 2nd Embodiment.

  Hereinafter, each embodiment in which the idle stop control device is applied to an engine of a two-wheeled vehicle will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic diagram showing an engine 10 (internal combustion engine) mounted on a two-wheeled vehicle, and assumes an ignition ignition type four-cycle single-cylinder engine. The fuel in the fuel tank 11 is supplied to the fuel injection valve 13 by the fuel pump 12. The fuel injection valve 13 is a port injection type attached to the intake pipe 14, and the fuel injected from the fuel injection valve 13 becomes an air-fuel mixture together with the intake air whose inflow is adjusted by the throttle valve 15, and the combustion chamber 16. Flow into. Further, by controlling the primary current of the ignition coil device 17, a secondary current is caused to flow through the spark plug 18 to cause spark to ignite the air-fuel mixture.

  The fuel pump 12, the fuel injection valve 13, the ignition coil device 17, a starter motor 22 and a starter switch 26 described later are driven by being supplied with electric power from the battery 19. Further, the operation of these electric loads 12, 13, 17, and 22 is controlled by the ECU 20.

  The starter motor 22 that rotationally drives the crankshaft 21 (output shaft) when the engine is started also functions as a generator that is rotationally driven by the crankshaft 21 to generate electricity. That is, the starter motor 22 is driven by a motor when the engine is started, and generates power after the engine is started. The starter motor 22 is a three-phase AC brushless motor. Due to the rectification function of the inverter 23, the drive power discharged from the battery 19 is converted from direct current to alternating current when the motor is driven, and the generated power from the starter motor 22 is converted from alternating current to direct current during the power generation operation.

  Further, a projection for generating a pickup signal (see FIG. 3A) by the pickup sensor 28 is provided on the crankshaft 21, and the pickup signal is converted into an N signal (FIG. 3B by a waveform shaping circuit 29 in the ECU 20). )) And is input to the microcomputer of the ECU 20. The N signal is a signal representing the rotation angle of the crankshaft 21 or the rotation phase of the starter motor 22.

  The two-wheeled vehicle shown in FIG. 1 can perform motor start for starting the engine 10 by the driving force of the starter motor 22 and kick start for starting the engine 10 by the driver's human power. That is, the two-wheeled vehicle is provided with a kick pedal 24 and a speed reducer 25, and when the driver steps on the kick pedal 24, the stepping force is transmitted to the crankshaft 21 via the speed reducer 25. The engine 10 is started (kick-started) by being rotated manually. The two-wheeled vehicle is provided with a starter switch 26. When the driver turns on the starter switch 26, the starter motor 22 is driven and the engine 10 is started (motor start) by the motor driving force.

  Further, the two-wheeled vehicle has an idle stop function described below. That is, when a predetermined idle stop condition is satisfied, the ECU 20 stops the operation of the ignition coil device 17 and the fuel injection valve 13 and automatically stops the engine 10. Specific examples of the idle stop condition include that the remaining capacity of the battery 19 is equal to or greater than a determination threshold, the rotational speed of the crankshaft 21 (engine rotational speed NE) is less than a predetermined value, and the vehicle speed is less than a predetermined speed. The throttle operation is not performed, the driver does not intend to accelerate, and the driver is operating the brake.

  When a predetermined start condition is satisfied, the ECU 20 drives the starter motor 22 and automatically restarts the operation of the ignition coil device 17 and the fuel injection valve 13 to automatically restart the engine 10 by starting the motor. . Specific examples of the starting condition include that the throttle is operated and the driver has an intention to accelerate, and that the driver is not operating the brake.

  However, after the kick start is executed, the ECU 20 prohibits the automatic stop by the idle stop function even when the idle stop condition is satisfied. Hereinafter, the control procedure of the idle stop function according to whether or not automatic stop is prohibited will be described in detail with reference to FIG. Note that the process of FIG. 2 is repeatedly executed at a predetermined cycle by the microcomputer of the ECU 20.

  First, in step S10 (kick start determination means) shown in FIG. 2, it is determined whether the previous engine start was a motor start or a kick start. If it is determined that the motor is started, it is checked in subsequent steps S11 and S12 whether or not the battery 19 has deteriorated.

  That is, in step S11, the terminal voltage (battery voltage) of the battery 19 that is in the process of supplying power to the starter motor 22 at the previous motor start, or the battery voltage when the power supply to the starter motor 22 is completed. Is greater than or equal to a predetermined value Vth. If it is determined that the battery voltage ≧ Vth, it is considered that the battery 19 is in a normal state in which the amount of power stored in the battery 19 is equal to or greater than a predetermined amount and is not deteriorated.

  In the next step S12, it is determined whether or not the engine speed NE during the supply of power to the starter motor 22 has reached a predetermined value NEth at the previous motor start. If it is determined that NE ≧ NEth, it is considered that the stored amount of the battery 19 is equal to or greater than a predetermined amount and the battery 19 is in a normal state without deterioration.

  If it is determined in step S10 that the motor is started and it is determined that the battery is in a normal state (S11: YES, S12: YES), the next idle stop is permitted in subsequent step S13. That is, the engine 10 is automatically stopped when the idle stop condition described above is satisfied during engine operation.

  On the other hand, when it is determined in step S10 that kick start has been performed (S10: YES), or when it is determined that the battery is in a deteriorated state (S11: NO, S12: NO), subsequent step S14 (idle stop prohibition) In the control means), the next idle stop is prohibited.

  Next, a method for determining which of the motor start and the kick start in step S10 described above will be described with reference to FIGS.

  3 is a time chart at the time of motor start, FIG. 4 is a time chart at the time of kick start, (a) corresponds to a waveform of a pickup signal output from the pickup sensor 28, and (b) corresponds to a command signal to the ignition coil device 17. N signal after waveform shaping, (c) ignition voltage (primary voltage of ignition coil device 17), (d) battery voltage, (e) starter voltage of power supplied to starter motor 22, each time Showing change. The waveform-shaped N signal shown in (b) is obtained by shaping the waveform of the pickup signal shown in (a).

  In FIG. 3 (motor start), when the starter switch 26 is turned on or automatically restarted and the starter motor 22 starts to be driven at time tm, the starter voltage increases and the battery voltage decreases (FIGS. 3D and 3E). )reference). As the crankshaft 21 starts rotating, a pickup waveform synchronized with the rotation and an N signal after waveform shaping appear (see FIGS. 3A and 3B). Then, after the reference position determination is completed by detecting the missing tooth portion, an ignition voltage is generated at a timing when a predetermined time elapses or when an edge of the N signal appears a predetermined number of times, and the ignition plug 18 discharges (ignitions). ) Thereby, the combustion in the combustion chamber 16 is started and the motor start is completed.

  In FIG. 4 (kick start), immediately after the time point tk when the kick pedal 24 is depressed, the pickup signal waveform and the N signal waveform appear in synchronization with the rotation of the crankshaft 21 (FIG. 4 ( a) (b)). Then, after the reference position determination is completed by detecting the missing tooth portion, an ignition voltage is generated at a timing when a predetermined time elapses or when an edge of the N signal appears a predetermined number of times, and the ignition plug 18 discharges (ignitions). ) Thereby, the combustion in the combustion chamber 16 starts and the kick start is completed.

  As can be seen by comparing FIG. 3 and FIG. 4, the motor starting and the kick starting differ in the following three points. That is, the first point is a change in the starter voltage. In the case of motor start, the starter voltage becomes a predetermined value (for example, 12 V) or more, whereas in the case of kick start, the starter voltage remains 0V.

  The second point is the discharge interval at the spark plug 18. The rotation speed of the crankshaft 21 when the crankshaft 21 is rotated by human power by the kick pedal 24 is faster than the rotation speed when the crankshaft 21 is rotated by the driving force by the starter motor 22. Therefore, in the case of kick start, the interval at which the waveform of the pickup signal changes is shorter than in the case of motor start, and the edge interval T15 of the N signal waveform is shortened.

  The third point is whether or not the battery voltage has dropped. In the case of motor start, the battery voltage drops at time tm due to the large power consumption in the starter motor 22. In contrast, in the case of kick start, the battery voltage does not drop at or immediately after tk. Specifically, in the example of FIG. 3D, the battery voltage drops to around 6V, whereas in the example of FIG. 4D, the battery voltage is stable between 10V and 14V.

  And in determining whether it is a motor start or a kick start in step S10, what is necessary is just to determine based on the difference of three points | pieces mentioned above. All three points may be determined as an AND condition, an OR condition, or may be determined based on any two or one of the three points.

  Here, if the battery 19 is deteriorated and is automatically stopped, the driving force of the starter motor 22 becomes insufficient at the next automatic restart, and the piston 27 does not get over the compression stroke of the engine 10 and is automatically restarted. There is a concern that the engine may fail to start and possibly cause reverse rotation of the crankshaft 21 to damage the components of the engine 10. In response to this concern, for example, if the above-mentioned determination threshold is set high and the idle stop condition is set severely, the above-mentioned concern about the automatic restart failure can be solved, but as a contradiction, the opportunity for automatic stop is reduced and the fuel consumption is sufficiently improved. It becomes impossible to plan.

  With respect to this problem, according to the present embodiment, after it is determined in step S10 that the kick start has been executed, automatic stop is prohibited even when the idle stop condition is satisfied (S14). Therefore, since automatic stop is prohibited based on the determination by the driver that the motor cannot be started, the motor start can be performed without setting the determination threshold used for determination of the idle stop condition (the remaining capacity of the battery 19 is equal to or greater than the determination threshold) to a large value. When it is not possible, automatic stop is prohibited. Therefore, the risk of automatic restart failure can be reduced without reducing the opportunity for automatic stop more than necessary.

(Second Embodiment)
In the present embodiment shown in FIG. 5, determination processing of step S10a and step S10b (return determination means) described below is added to the processing of the first embodiment shown in FIG. Hereinafter, the processing content of FIG. 5 will be described focusing on the difference from FIG. In FIG. 5, the description of the same reference numerals as those in FIG. The hardware configuration of the engine 10 and the like in the present embodiment is the same as that of the first embodiment shown in FIG.

  If it is determined in step S10 that the kick start has occurred, in the subsequent step S10a, whether or not the kick start has been executed within a predetermined time after the automatic restart has failed, or a starter switch It is determined whether or not the operation is performed within a predetermined time after the operation of No. 26.

  Specifically, when the starter motor 22 is energized and turned on, the state in which the N signal is not input continues for a predetermined time or more, or the starter motor 22 is energized and turned on. When the state where the speed does not exceed the predetermined number of rotations continues for a predetermined time or more, it is determined that the “automatic restart has failed”. Furthermore, when such “automatic restart failure” determination is established, the timer starts counting, and when kick start is executed during the period until the timer reaches a certain value, the result is affirmative in step S10a. judge.

  Further, at the time of kick start after the above-mentioned automatic restart failure determination has been made once, it may be determined that the kick start has been triggered by the motor start failure, and an affirmative determination may be made in step S10a.

  If it is determined that the automatic restart has not been executed within a predetermined time after the failure of the automatic restart or within a predetermined time after the starter switch 26 is operated (S10a: NO), the motor start has failed. Accordingly, it is not a case where the driver has kick-started, but a case where the driver has customarily started kick-start regardless of whether or not the battery is in a deteriorated state. In step S13, the next idle stop is permitted.

  On the other hand, when it is determined that the automatic restart has been executed within a predetermined time after the failure of the automatic restart or within a predetermined time after the starter switch 26 is operated (S10a: YES), the motor is associated with the battery deterioration. It is considered that the driver has started kicking due to the failure of starting, and the process proceeds to the next step S10b.

  In step S10b, it is determined whether or not the charged amount of the battery 19 has returned to a predetermined amount or more. For example, when the engine 10 is continuously operated for a certain period after the kick start has been made, it is determined that the remaining battery capacity has increased sufficiently and the return determination is made. Alternatively, after the kick start is performed, if the state in which the battery voltage has become equal to or higher than a predetermined value continues for a predetermined time or longer while the vehicle is traveling, it is determined that the remaining battery capacity has increased sufficiently and the return determination is made.

More specifically, in the determination in step S10b, when any of the following conditions (1) to (3) is satisfied, the charged amount of the battery 19 returns to a predetermined amount or more and the charged amount is sufficient. And affirmative determination is made in step S10b.
(1) When starting with the starter motor 22, the engine speed becomes a predetermined value (xrpm) or more within a predetermined value (msec) from the starter ON.
(2) When the state where the engine rotation speed is equal to or higher than the predetermined value (yrpm) continues for a predetermined value (z minutes) or more.
(3) When the battery voltage is equal to or higher than a predetermined value in the stop and starter OFF state.

When any of the following conditions (4) to (6) is satisfied, it is determined that the charged amount of the battery 19 is less than a predetermined amount and the charged amount is not sufficient, and a negative determination is made in step S10b.
(4) When automatic restart fails.
(5) When starting with the starter motor 22, when a predetermined value (msec) or more has elapsed from when the starter is turned on until the engine speed reaches a predetermined value (xrpm) or more.
(6) When the battery voltage is equal to or lower than a predetermined value in the stop and starter OFF state.

  If it is determined that the battery 19 has been restored (S10b: YES), the idle stop prohibition is canceled, and the process proceeds to step S13 to permit the next idle stop. On the other hand, when it is not determined that the battery 19 has been restored (S10b: NO), the process proceeds to step S14 and the next idle stop is prohibited.

  Here, depending on the driver, even if the battery deterioration has not progressed and the motor can be sufficiently started, there is a case where the kick start is customarily performed. Prohibiting automatic stop even in this case impairs compatibility between avoiding automatic restart failure and increasing opportunities for automatic stop. In this embodiment in consideration of this point, it is determined whether or not the kick start execution is triggered by the motor start failure based on the presence or absence of the motor start failure history, and the kick start is triggered by the motor start failure. Since the automatic stop is prohibited on the condition, the compatibility can be improved.

  Further, after the automatic stop is prohibited, when the remaining capacity of the battery 19 increases, or when the battery 19 is replaced with a new battery 19, the state where there is no risk of the automatic restart failure (S10b: YES), the automatic stop prohibition is canceled and the next idle stop is permitted (S13). Therefore, the compatibility can be improved even after the battery is restored.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be modified as follows. Moreover, you may make it combine the characteristic structure of each embodiment arbitrarily, respectively.

  -When the idle stop is prohibited in step S14, a notification means such as a warning lamp is operated to notify the driver that the idle stop is prohibited or the battery 19 is in a deteriorated state. Good.

  In the above embodiment, it is determined whether or not the kick start is based on whether or not the battery voltage has dropped, the change in the starter voltage, and the discharge interval. For example, an operation detection switch is provided in the kick pedal 24, and It may be determined whether or not the kick start is based on the presence or absence of the detection signal.

DESCRIPTION OF SYMBOLS 10 ... Engine, 22 ... Starter motor, 26 ... Starter switch, S10 ... Kick start determination means, S10b ... Return determination means, S14 ... Idle stop prohibition control means

Claims (4)

A motor start to start the engine by the driving force of the starter motor and a kick start to start the engine by the driver's human power are possible,
And it is applied to a vehicle having an idle stop function that automatically stops the engine when a predetermined idle stop condition is satisfied, and automatically restarts the engine by the motor start when a predetermined start condition is satisfied,
Kick start determining means for determining whether or not the kick start has been executed;
After the execution of the kick start is determined, idle stop prohibition control means for prohibiting the automatic stop even when the idle stop condition is satisfied,
An idle stop control device comprising:   If it is determined that the kick start has been executed, the automatic start by the idle stop prohibition control means is performed on the condition that the kick start has been executed within a predetermined time after the automatic restart has failed. The idle stop control device according to claim 1, wherein the stop is prohibited. The vehicle is configured to start the motor when a starter switch is operated by a driver.
If it is determined that the kick start has been executed, the automatic stop is performed by the idle stop prohibition control means on the condition that the kick start is executed within a predetermined time after the starter switch is operated. The idle stop control device according to claim 1, wherein the idle stop control device is prohibited. A return determination means for determining whether or not a storage amount of a battery that supplies power to the starter motor has returned to a predetermined amount or more;
The automatic stop prohibition by the idle stop prohibition control means is canceled when it is determined that the return determination means has returned after it is determined that the kick start has been executed. The idle stop control apparatus as described in any one.

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