JP2006152965A - Vehicle, control device for vehicular engine and engine control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle such as a four wheel vehicle and motorcycle provided with an engine, and a control method for the engine applied to such vehicles. <P>SOLUTION: The engine is stopped (S27, S28, S29) if an idling stop condition is satisfied(S7). A starter motor and a fuel pump are started (S21, S22) and fuel injection and ignition control (step S23) are performed and throttle opening corresponding to engine temperature is set (S25, 26) when a recovery condition from idling stop is satisfied and start request is issued (S20). The throttle opening is set irrespective of the acceleration command value. Engine output regulation process (S14) is performed as a need arises if the engine starts (YES in S8). The engine output regulation process includes an ignition timing retard correction process and a following delay process setting following delay time of throttle opening in relation to acceleration command value. Consequently, re-startability of the engine is improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle such as a four-wheeled vehicle or a motorcycle equipped with an engine, and an engine control device and an engine control method applied to such a vehicle.

An idle stop system is known in which an engine that is a driving source of a vehicle is stopped when a predetermined stop condition is satisfied during operation, and is restarted when a predetermined return condition is satisfied while the engine is stopped. For example, in the idle stop system disclosed in Patent Document 1 below, a configuration is disclosed in which the engine is restarted in response to an accelerator operation being performed while the engine is stopped.
Japanese Patent Laid-Open No. 11-257123

However, some drivers may operate the accelerator excessively in order to restart the engine quickly. As a result, the throttle opening becomes excessive in correspondence with a large accelerator operation amount. For this reason, the air-to-fuel ratio at the time of restart is not appropriate, and not only restartability may be deteriorated, but also exhaust gas containing a lot of harmful components may be discharged.
Even if the accelerator operation is not excessive, depending on the state of the engine (particularly the engine temperature), an appropriate air-to-fuel ratio may not always be obtained, and good restartability may not be realized. Specifically, the appropriate air-to-fuel ratio varies depending on the engine temperature, but in the conventional technology in which the throttle opening depends on the accelerator operation, the intake air amount becomes excessive and insufficient, and an appropriate air-to-fuel ratio is obtained. The probability is low.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle, an engine control device, and an engine control method that can improve the restartability of a stopped engine.

  In order to achieve the above object, an invention according to claim 1 is provided with an engine that includes a throttle driven by an electric motor and generates a driving force for driving a wheel, and a predetermined effect that affects a starting characteristic of the engine. An engine startability detecting means for detecting a physical quantity, an accelerator operated by a driver for controlling the output of the engine and generating an accelerator command value corresponding to the operation amount, and an accelerator command value generated from the accelerator Engine output control means for controlling the engine output based on the engine output control means for stopping the engine in response to satisfaction of a predetermined engine stop condition, and the engine The engine that has been stopped by the stop control means is restarted in response to a predetermined restart condition being satisfied. A restart control means for controlling the electric motor based on an accelerator command value from the accelerator, a throttle opening control means for controlling a throttle opening, and the restart control means for restarting the engine. When the engine is restarted, the restart throttle throttle opening control means sets the restart throttle opening according to the physical quantity detected by the engine startability detecting means without depending on the accelerator command value. An opening degree setting means is included.

  According to this configuration, when the engine stop condition is satisfied, the engine is automatically stopped. Thereafter, when the restart condition is satisfied, the engine is restarted. The engine includes a throttle (electronically controlled throttle) driven by an electric motor, and can control the throttle opening independently of the operation of the accelerator. Therefore, the throttle opening is controlled based on the accelerator command value during normal times (when not starting), but depending on the detection result by the engine startability detecting means at the time of restart, regardless of the accelerator command value. The restart throttle opening is set. Accordingly, by setting an appropriate restart throttle opening degree according to the state of the engine, an appropriate air-to-fuel ratio is realized, and good restartability can be realized without depending on whether the accelerator operation is good or bad. In addition, by setting an appropriate air-to-fuel ratio, it is possible to suppress or prevent exhaust gas containing a lot of harmful substances.

The restart condition may include that the accelerator command value is equal to or greater than a predetermined value. In this case, even if the operator performs an excessive accelerator operation, an appropriate throttle opening can be set regardless of the accelerator operation. Generally, in this case, the throttle opening is set smaller than a value corresponding to the accelerator command value.
The restart condition may include that the release of the brake lever is detected. In this case, the accelerator command value is generally a value corresponding to a very small throttle opening. In this case, generally, the throttle opening is set larger than a value corresponding to the accelerator command value.

For example, the vehicle may further include a rotation speed response clutch means for transmitting the driving force of the engine to the wheels in response to the engine reaching a predetermined transmission rotation speed. In this case, it is preferable that the restart throttle opening setting means sets a restart throttle opening at which the engine speed is equal to or lower than the transmission speed.
Thereby, even when the accelerator operation at the time of restart is excessive, the engine speed (rotation speed) does not reach the transmission speed immediately after restart. Therefore, there is no case where the engine speed response clutch means is inadvertently engaged after restart and the driving force of the engine is not transmitted to the wheels. As a result, the driving force is not transmitted to the wheels earlier than the driver intends, and an inadvertent start accompanying the restart of the engine can be prevented.

A typical example of the rotational speed response clutch means is a centrifugal clutch that clutches in at a predetermined transmission rotational speed by utilizing a centrifugal force generated with the rotation of the engine.
According to a second aspect of the present invention, the engine startability detecting means includes engine temperature detecting means for detecting the temperature of the engine, and the restart throttle opening setting means determines the restart throttle opening as the engine temperature. 2. The vehicle according to claim 1, wherein the vehicle is determined according to an engine temperature detected by the detecting means.

According to this configuration, by setting the restart throttle opening degree according to the engine temperature, it is possible to realize an appropriate air-to-fuel ratio at the time of restart, so that the restartability can be improved and the exhaust gas into the exhaust gas can be improved. Mixing of harmful components can be suppressed. Generally, the restart throttle opening may be set between a predetermined upper limit value and lower limit value so as to increase as the engine temperature decreases.
Examples of the engine temperature detecting means include one that detects the temperature of engine cooling water, one that detects the wall temperature of the head, one that detects the wall temperature of the cylinder, and one that detects the temperature of the lubricating oil. it can.

According to a third aspect of the present invention, the restart throttle opening setting means sets the restart throttle opening corresponding to the accelerator command value according to the physical quantity detected by the engine startability detecting means. 3. The vehicle according to claim 1, wherein the vehicle is set to be larger than the opening degree.
Thereby, for example, even when the accelerator command value corresponds to the throttle fully closed, a restart throttle opening larger than the fully closed is set. Thereby, since an optimal air-to-fuel ratio is achieved, good restartability can be realized, and exhaust gas containing a lot of harmful components can be suppressed or prevented.

  According to a fourth aspect of the present invention, the throttle opening control means is an accelerator command value generated by the accelerator from a restart throttle opening set by the restart throttle opening setting means after the engine is restarted. The vehicle according to any one of claims 1 to 3, wherein the throttle opening is gradually changed to a throttle opening corresponding to the above.

According to this configuration, after the restart, the throttle opening is gradually increased or decreased from the restart throttle opening to a value corresponding to the accelerator command value, so that the engine output corresponding to the accelerator command value is increased. Gradually move to a state where you can get it. As a result, engine control in accordance with the driver's intention is possible.
The follow-up delay time of the throttle opening with respect to the accelerator command value is preferably determined according to the throttle opening deviation. The follow-up delay time is more preferably determined according to the vehicle speed. For example, when the throttle opening deviation exceeds a predetermined threshold value, a tracking delay time larger than the normal tracking delay time may be determined according to the vehicle speed.

A fifth aspect of the present invention is the vehicle according to any one of the first to fourth aspects, wherein the accelerator is a manual operation type accelerator that is operated by a driver's hand.
The manually operated accelerator is mainly used in two-wheeled vehicles, but is also used in four-wheeled vehicles such as ATV (All Terrain Vehicle). The manual accelerators of these vehicles are configured by attaching an accelerator grip that can be rotated around the handle shaft to one end of a handle shaft that extends to the left and right.

  A sixth aspect of the present invention is an engine control device for a vehicle that is controlled by an accelerator operation and drives wheels by an engine having a throttle that is driven by an electric motor, and has a predetermined effect on the starting characteristics of the engine. Engine startability detecting means for detecting a physical quantity of the engine, engine stop control means for stopping the engine in response to satisfaction of a predetermined engine stop condition, and the engine stop control means for stopping the engine. A throttle control is controlled by controlling the electric motor based on an accelerator command value from the accelerator, and restart control means for restarting the engine in response to satisfaction of a predetermined restart condition. When the engine is restarted by the throttle opening control means and the restart control means The restart throttle opening setting means for setting the restart throttle opening according to the physical quantity detected by the engine startability detecting means without depending on the accelerator command value with respect to the throttle opening control means And an engine control device characterized by comprising:

With this configuration, an appropriate throttle opening can be reliably set at the time of restart, and an appropriate air-to-fuel ratio can be obtained, so that good restartability can be ensured. Moreover, it is possible to suppress or prevent a large amount of harmful components from being mixed into the exhaust gas.
According to a seventh aspect of the present invention, the engine startability detecting means includes engine temperature detecting means for detecting the temperature of the engine, and the restart throttle opening degree setting means determines the restart throttle opening degree as the engine temperature. 7. The engine control device according to claim 6, wherein the engine control device is determined according to an engine temperature detected by the detecting means.

According to this configuration, since an appropriate restart throttle opening can be set according to the engine temperature, restartability can be improved, and harmful components in the exhaust gas during restart can be reduced.
According to an eighth aspect of the present invention, the restart throttle opening setting means sets the restart throttle opening corresponding to the accelerator command value in accordance with the physical quantity detected by the engine startability detecting means. 8. The engine control device according to claim 6, wherein the engine control device is set to be larger than the opening degree.

With this configuration, even if the accelerator command value at the time of restart is a value corresponding to a very small throttle opening such as full throttle, the restart throttle opening required to obtain the optimal air-to-fuel ratio is set. can do. Thereby, restartability can be improved and the harmful component in exhaust gas at the time of restart can be reduced.
According to a ninth aspect of the present invention, the throttle opening control means is an accelerator command value generated by the accelerator from a restart throttle opening set by the restart throttle opening setting means after the engine is restarted. The engine control device according to any one of claims 6 to 8, wherein the throttle opening is gradually changed to a throttle opening corresponding to.

According to this configuration, since the restart throttle opening is set regardless of the accelerator command value, the operation gradually shifts from the throttle opening corresponding to the accelerator command value. Engine output control corresponding to the user's intention.
A tenth aspect of the present invention is an engine control method for a vehicle that is controlled by an accelerator operation and drives wheels by an engine having a throttle that is driven by an electric motor, and that affects a starting characteristic of the engine. An engine startability detecting step for detecting a physical quantity of the engine, an engine stop step for stopping the engine in response to satisfaction of a predetermined engine stop condition, and the engine stopped by the engine stop step. A restart step for restarting in response to satisfaction of a predetermined restart condition, and when the engine is restarted by the restart step, the throttle opening is set to the accelerator command value. Regardless of the restart, the engine startability detection means detects the physical quantity according to the physical quantity. An engine control method characterized by including the step of controlling the electric motor such that the throttle opening degree.

  By this method, the throttle opening at the time of restart can be set appropriately regardless of whether or not the accelerator operation is appropriate, so that the engine can be restarted reliably and exhaust gas containing many harmful components can be discharged. Can be suppressed or prevented.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an illustrative view for illustrating the configuration of a two-wheeled vehicle 1 (including a motorcycle and a motor-equipped bicycle) that is a vehicle according to an embodiment of the present invention. The two-wheeled vehicle 1 is a so-called scooter type that does not involve manual clutch operation when starting. The two-wheeled vehicle 1 includes a body frame 2, a power unit 3 attached to the body frame 2 so as to be swingable up and down, a rear wheel 4 that rotates by obtaining driving force from the power unit 3, A front wheel 6 as a steering wheel attached to the front portion of the vehicle body frame 2 via a front fork 5 and a handle 7 that rotates integrally with the front fork 5 are provided.

  The power unit 3 is swingably connected to a lower portion near the center of the body frame 2 and is elastically coupled to the rear portion of the body frame 2 via a rear cushion unit 8. A driver's seat 9 is disposed at an upper portion near the center of the vehicle body frame 2, and a passenger's seat 10 is disposed behind the driver's seat 9. In the body frame 2, a footrest portion 11 is provided at a position between the seat 9 and the handle 7. The front wheel 6 and the rear wheel 4 are provided with a front brake unit 12 and a rear brake unit 13, respectively.

  The power unit 3 includes an engine 15 and a transmission case 16 that are integrally formed. The driving force from the starter motor 18 is transmitted to the crankshaft 17 of the engine 15 via the belt 19 when the engine 15 is started. A drive pulley 22 to which the rotation of the crankshaft 17 is transmitted via the gears 20 and 21 and a rotation of the drive pulley 22 are transmitted to the transmission case 16 via the belt 25 and coupled to the rear wheel 4. A pulley 23 and a centrifugal clutch 24 that switches between a state in which the rotation of the gear 21 is transmitted to the drive pulley 22 and a state in which the rotation is not transmitted are accommodated.

  When the rotational speed (rotational speed) of the engine 15 reaches a predetermined transmission rotational speed, the centrifugal clutch 24 couples the gear 21 and the drive pulley 22 to transmit the driving force from the engine 15 side to the drive pulley 22. It is a rotation speed response clutch. Thereby, when the rotation speed of the engine 15 reaches the transmission rotation speed, the driving force of the engine 15 is transmitted to the rear wheel 4 and the two-wheeled vehicle 1 can be started.

  FIG. 2 is a schematic plan view for explaining a configuration related to the handle 7. The handle 7 is disposed at the handle shaft 26 extending left and right, and the left end portion and the right end portion of the handle shaft 26. The left grip portion 27 and the right grip portion 28 (hand-operated accelerator) that the driver holds with the left hand and the right hand, respectively And a rear brake lever 29 provided in association with the left grip portion 27, a front brake lever 30 provided in association with the right grip portion 28, and a handle that covers a region between the left and right grip portions 27, 28. And a cover 31.

  The right grip portion 28 also serves as an accelerator operation portion, and is attached so as to be rotatable around the handle shaft 26. By rotating the right grip portion 28 toward the front as viewed from the driver, the throttle opening of the engine 15 can be increased, and the engine output can be increased and rotated to the opposite side (front side). By doing so, the throttle opening can be reduced, and the engine output can be reduced. An accelerator operation amount sensor 32 that detects such a rotation operation amount of the right grip portion 28 as an accelerator operation amount and generates an accelerator command value (accelerator command signal) is provided in association with the right grip portion 28. . The accelerator operation amount sensor 32 can be constituted by, for example, a potentiometer.

  The rear brake lever 29 is a brake operation unit that is operated by the driver in order to operate the rear brake unit 13 and apply a braking force to the rear wheels. Similarly, the front brake lever 30 is a brake operation unit that is operated by the driver in order to operate the front brake unit 12 and apply a braking force to the front wheels. The operation of the brake levers 29 and 30 may be transmitted to the brake units 13 and 12 by wires, or the brake units 13 and 12 by a hydraulic mechanism that operates in response to an operation input of the brake levers 29 and 30. May be actuated. In either case, the front wheel 6 is brought into a braking state by grasping the front brake lever 30, and the front wheel 6 is released from the braking state by releasing this. Similarly, the rear wheel 4 is brought into a braking state by gripping the rear brake lever 29, and the rear wheel 4 is released from the braking state by releasing it.

An instrument panel 35 is incorporated in the center of the handle cover 31. A main switch 34 for enabling the engine 15 to start can be located at a position closer to the right grip portion 28 than the instrument panel 35, and an engine A starter switch 36 for starting 15 is arranged. A speedometer 37 and a fuel gauge 38 are incorporated in the instrument panel 35.
FIG. 3 is a block diagram showing a configuration mainly related to the control of the engine 15 of the two-wheeled vehicle 1. The engine 15 is, for example, a fuel injection type engine, for example, a single-cylinder four-cycle engine. The two-wheeled vehicle 1 is integrated with an FI (Electronic Fuel Injection System) controller (electronic control unit) 70 as an engine output control means for electronically controlling fuel injection of the engine 15, a generator and the starter motor 18 described above. An ISG (Integrated Starter Generator) 72, an ISG controller 71 for controlling the ISG 72, and a battery 75 are mounted.

The FI controller 70 receives a cam signal that is an output signal of a cam sensor 52 that detects a cam position from the movement of a timing rotor (not shown) attached to the cam shaft 51 of the engine 15. The stroke determination of the engine 15 is performed using this cam signal.
Further, the FI controller 70 receives a crank angle signal that is an output signal of a crank angle sensor 54 that detects a crank position from the movement of a timing rotor (not shown) attached to the crankshaft 17 of the engine 15. This crank angle signal is a detection result of the crank angle of the engine 15. The FI controller 70 detects the rotation speed of the engine 15 by detecting the interval (cycle) of the crank angle signal.

  Further, the FI controller 70 receives a vehicle speed signal that is an output signal of a magnet sensor 55 that detects the vehicle speed of the two-wheeled vehicle 1 from the movement of the driven pulley 23 attached to a wheel (for example, the rear wheel 4). The vehicle speed of the two-wheeled vehicle 1 is detected by the time interval of output pulses output from the magnet sensor 55. That is, the FI controller 70 detects the wheel rotation speed of the two-wheeled vehicle 1 by detecting the interval (cycle) of the vehicle speed signal, and converts the wheel rotation speed into the vehicle speed.

Further, the FI controller 70 receives a starter signal output when the starter switch 36 attached to the handle 7 of the two-wheeled vehicle 1 is turned on. In the two-wheeled vehicle 1, the starter signal is used as a start signal for the engine 15. The scooter is configured such that the engine 15 cannot be started unless the brake is in a braking state.
Further, a throttle opening signal indicating the throttle opening of a butterfly valve type throttle 45 provided in the intake pipe 40 of the engine 15 is input to the FI controller 70 from the throttle controller 42. The throttle controller 42 is supplied with an output signal of a throttle position sensor 46 that detects the opening degree of the throttle 45. The throttle position sensor 46 outputs an output signal that changes linearly according to the throttle opening. In order to electronically control the opening degree of the throttle 45, an electric motor 41 that drives the throttle 45 is coupled to the throttle 45. The electric motor 41 is controlled by the throttle controller 42. The throttle controller 42 is fed back with the output signal of the throttle position sensor 46 and is provided with a throttle opening command signal from the FI controller 70. That is, the throttle controller 42 feedback-controls the electric motor 41 based on the output of the throttle position sensor 46 so that the opening degree of the throttle 45 matches the throttle opening degree command signal.

An intake pipe negative pressure sensor 43 that detects a negative pressure in the intake pipe 40 is disposed downstream of the throttle 45 in the intake pipe 40 in the intake direction. The output signal of the intake pipe negative pressure sensor 43 is input to the FI controller 70.
Further, the FI controller 70 receives an engine temperature signal that is an output signal of the temperature sensor 48 that detects the temperature of the engine 15. The FI controller 70 knows the warm-up state (ease of restart) of the engine 15 based on the engine temperature signal. The temperature sensor 48 may be attached to the cylinder block of the engine 15 and detect the temperature of the cylinder block. Further, when the cooling method of the engine 15 is a water cooling type, a water temperature sensor that detects the temperature of the cooling water may be disposed in the radiator, and the engine temperature may be estimated based on the output of the water temperature sensor.

A front brake signal is input to the FI controller 70. That is, the operation state of the front brake lever 30 is detected by the front brake switch 57 (see FIG. 2) and is input to the FI controller 70 as an ON / OFF signal (front brake signal).
Further, the rear brake signal is input to the FI controller 70. That is, the operation state of the rear brake lever 29 is detected by the rear brake switch 58 (see FIG. 2), and is input to the FI controller 70 as an ON / OFF signal (rear brake signal). The FI controller 70 detects the braking state of the corresponding brake units 12 and 13 based on the two brake signals.

Further, the battery voltage is input from the battery 75 to the FI controller 70.
On the other hand, an injector (INJ: fuel injection device) 60, an ignition coil (IGN) 61 and a fuel pump 62 are connected to the output terminal of the FI controller 70.
From the FI controller 70, a start signal for starting the ISG 72, a generated current command value of the ISG 72, and a generated voltage command value are given to the ISG controller 71. Thereby, the ISG controller 71 drives the ISG 72 and receives a rotation signal from the ISG 72.

The ISG 72 is driven by the engine 15 to generate power. The electric power generated by the ISG 72 is charged to the battery 75 via the ISG controller 71. The battery 75 supplies power to the drive circuit of each electrical component.
The start signal is output as a start request from the FI controller 70 to the ISG controller 71 when the starter signal is detected or when the restart condition from the idle stop is satisfied.

The two-wheeled vehicle 1 according to the present embodiment is configured to idle stop the engine 15 under the control of the FI controller 70 when all predetermined execution conditions are satisfied in order to suppress unnecessary fuel consumption during idling. ing.
FIG. 4 shows execution conditions (1) to (6) (engine stop conditions) when the engine 15 of the two-wheeled vehicle 1 according to this embodiment is idle-stopped.

Execution condition (1): The engine temperature is a predetermined value or more. Whether the engine temperature is a predetermined value (for example, 65 ° C.) or not is whether the engine temperature signal output from the temperature sensor 48 is a predetermined value or more. Judge by no. This determination is to determine whether the engine temperature is a temperature at which the engine 15 may be idle-stopped. In other words, it is determined whether the engine temperature is so high that the engine 15 can be easily restarted even when the engine 15 is stopped. Therefore, the engine temperature of the execution condition (1) is not limited to 65 ° C. or higher.

Execution condition (2): The vehicle speed has once exceeded a predetermined value. Whether the vehicle speed has once exceeded a predetermined value (for example, 10 km / h) is determined by whether the motorcycle 1 has traveled immediately before the engine 15 is idle-stopped. Whether or not is determined by, for example, a vehicle speed signal. This condition is mainly based on the fact that the battery 75 may not be sufficiently charged during low-speed traveling. That is, it is determined whether or not the battery 75 is sufficiently charged so that the engine 15 can be easily restarted even when the engine 15 is stopped. Therefore, the vehicle speed of the execution condition (2) is not limited to 10 km / h or more.

Execution condition (3): The battery voltage is a predetermined value or more. Whether the battery voltage is a predetermined value (for example, 12.0 V) or not is determined by whether the battery voltage supplied to the FI controller 70 is a predetermined value or more. Judge by whether or not. This determination is to determine whether or not a sufficient amount of electric power for restarting the engine 15 is secured. Therefore, the battery voltage of the execution condition (3) is not limited to 12.0V or more.

Execution condition (4): The brake switch is ON. The front brake signal of the front brake switch 57 or the rear brake signal of the rear brake switch 58 is input to the FI controller 70 to determine whether or not the brake switch is ON. Judgment by whether or not. This determination is to determine whether or not the operator is willing to stop the two-wheeled vehicle 1.

Execution condition (5): The throttle is in the fully closed state and the idle speed. Whether the throttle 45 is in the fully closed state and the engine speed is the idle speed is determined by the throttle controller 42 from the throttle controller 42. This can be determined from the degree signal (representing the detection result of the throttle position sensor 46) and the crank angle signal of the crank angle sensor 54. This determination is to determine whether or not the engine 15 is idling at a predetermined speed or less with the throttle fully closed. Here, whether or not the throttle 45 is in the fully closed state can be determined by the fact that the intake pipe negative pressure of the engine 15 is the negative pressure during idling without using the throttle opening signal of the throttle position sensor 46. It is possible to judge. The intake pipe negative pressure can be obtained based on the output signal of the intake pipe negative pressure sensor 43, and can be detected by looking at the bottom pressure of the intake pipe immediately before the intake port of the engine 15 is closed. This makes it possible to determine whether or not the throttle 45 is fully closed by an inexpensive method.

Execution condition (6): A predetermined time or more has elapsed since the vehicle speed became zero. Whether or not a predetermined time (for example, 3 seconds) has elapsed since the vehicle speed became zero (0 km / h) This is determined by the interval between output pulses output from the magnet sensor 55 (see FIG. 1) and a timer (not shown) built in the FI controller 70. Here, the state in which the vehicle speed is zero becomes difficult to detect because the wheels are not rotating. Therefore, in this two-wheeled vehicle 1, the vehicle speed is zero when the interval between the output pulses of the magnet sensor 55 corresponding to the rotational speed of the driven pulley 23 coupled to the rear wheel 4 is increased to some extent. In addition, for example, in the case of a temporary stop at a crossing, for example, the engine 15 is frequently idle-stopped so that the engine 15 is not idle-stopped. This is to prevent it from happening. Therefore, the elapsed time after the vehicle speed of the execution condition (6) becomes zero is not limited to 3 seconds. The vehicle speed can also be detected by the front wheels 6.

In the present embodiment, in the two-wheeled vehicle 1, when all of the execution conditions (1) to (6) described above are satisfied, fuel injection and ignition are immediately stopped, and the engine 15 is idle-stopped. Note that the execution condition (2) may not be an indispensable condition for idle stop unless the troublesomeness caused by frequent restarts is considered.
On the other hand, in the present embodiment, the two-wheeled vehicle 1 is configured to restart the engine 15 that has been idle-stopped when at least one predetermined return condition (restart condition) described below is satisfied. Yes.

FIG. 5 shows return conditions (1) to (5) when the idle stop is canceled and the engine 15 is restarted in the two-wheeled vehicle 1 according to the present embodiment.
Return condition (1): Brake released Whether or not the brake switch is turned ON is determined by whether or not the front brake lever 30 or the rear brake lever 29 is released. That is, this determination is made based on whether or not the front brake signal of the front brake switch 57 or the rear brake signal of the rear brake switch 58 has been input to the FI controller 70. That is, in the two-wheeled vehicle 1, when the operator releases the front brake lever 30 or the rear brake lever 29, the engine 15 that is idle-stopped is restarted.

  More specifically, a) When both the front brake and the rear brake are applied during idling stop, the operation part (brake lever) is arranged on the same side as the accelerator (right grip part 28). The release of the front brake is the release condition for idle stop. B) When only the rear brake is applied during the idle stop, the release of the rear brake is set as a condition for releasing the idle stop. C) When only the front brake is applied during the idle stop, the release of the front brake is set as the idle stop release condition.

Return condition (2): The accelerator command value is greater than or equal to a predetermined value. It is determined whether or not the accelerator command value is equal to or greater than a predetermined value (for example, a value corresponding to 22 ° in terms of throttle opening). The determination is made based on the accelerator command value detected by the sensor 32 and input to the FI controller 70. This determination is made to determine whether or not the operator is willing to start the two-wheeled vehicle 1 by turning the right grip (accelerator grip) 28 of the steering wheel. Therefore, the predetermined value of the return condition (2) is not limited to the accelerator command value corresponding to 22 ° in terms of the throttle opening.

Return condition (3): The starter switch is turned on Whether the starter switch 36 is turned on is determined by whether the starter signal of the starter switch 36 is input to the FI controller 70 or not. This determination is to determine whether or not the operator has a will to start the two-wheeled vehicle 1 by pressing the starter switch 36. When the starter switch 36 is turned on and the engine 15 is restarted, a starter signal is output while the starter switch 36 is on. However, the duration of the starter signal output by operating the starter switch 36 once is limited to a certain time (for example, 2.5 seconds). Further, when the engine 15 is automatically returned except for the return condition (3), a starter signal is output for a certain time (for example, 2.5 seconds).

Return condition (4): The engine temperature has fallen below a predetermined value. Whether the engine temperature has fallen below a predetermined value (for example, 55 ° C.) is determined by whether the engine temperature signal of the temperature sensor 48 has fallen below a predetermined value. To do. This determination is to determine whether or not the engine temperature is maintained at or above a temperature at which the engine 15 can be restarted smoothly. In other words, in the two-wheeled vehicle 1, since the engine 15 is restarted when the engine temperature falls below a predetermined value, the engine temperature is maintained at least at a predetermined value or more. The engine temperature of the return condition (4) is not limited to 55 ° C.

Return condition (5): The battery voltage has fallen below a predetermined value. Whether the battery voltage has fallen below a predetermined value (for example, 11.8 V) is determined by whether the battery voltage applied to the FI controller 70 has fallen below a predetermined value. Judge. The predetermined value at this time is set to a value lower than the battery voltage for determining whether or not to execute idle stop. Even during idle stop, for example, the power of the battery 75 is consumed by the brake lamp. When the amount of electric power stored in the battery 75 becomes a predetermined value or less, it cannot be reliably restarted. Therefore, when the battery voltage becomes equal to or lower than the predetermined value, the engine 15 is restarted and the battery 75 is charged even if the vehicle is stopped. The battery voltage of the return condition (5) is not limited to 11.8V.

Next, the state transition of the two-wheeled vehicle 1 according to this embodiment will be described.
FIG. 6 is a state transition diagram showing state transition of the engine 15 of the two-wheeled vehicle 1. The engine 15 makes a timely transition to “stop mode”, “start mode”, “idle stop mode”, and “normal operation mode” under predetermined conditions. The “normal operation mode” includes a “steady operation mode” and a “transient operation mode”. State data indicating which state (mode) the engine 15 is in is stored in a state management memory (not shown) in the FI controller 70.

In FIG. 6, when the main switch 34 (see FIG. 2) is turned on in the “power OFF” state, the engine 15 enters the “stop mode” (T1).
Further, the engine 15 shifts to the “start mode” when the driver turns on the starter switch 36 or performs cranking by pushing or kicking in the “stop mode” (T2). When an engine stall occurs in the “start mode”, the engine 15 returns to the “stop mode” (T3). When the engine 15 is ignited in the “start mode” and reaches a predetermined complete explosion determination rotational speed, the engine 15 transitions to the “warm-up mode” in the “steady operation mode” (T4).

The engine 15 is in the “normal operation mode”, and when the main switch 34 is turned off, the engine 15 is turned “power off” (T5), and when the stop switch (not shown) is turned on, the engine 15 is placed in the “stop mode” (T6).
On the other hand, when all of the above-described idle stop execution conditions (1) to (6) are satisfied in the “steady operation mode”, the engine 15 transitions to the “idle stop mode” (T7). Then, when any one of the return conditions (1) to (5) described above is satisfied, the engine 15 that has transitioned to the “idle stop mode” transitions again to the “start mode” and is restarted (T8). ).

In addition, when the engine 15 operating in the “normal operation mode” is determined to be accelerated in the “steady operation mode”, the engine 15 is shifted to the “transient operation mode” and accelerated (T9). The engine 15 that has been accelerated and transitioned to the “transient operation mode” returns to the “steady operation mode” upon completion of acceleration (T10).
The engine 15 that has transitioned to the “transient operation mode” repeats “acceleration (T11)” and “deceleration (T12)” by rapid deceleration and reacceleration.

The engine 15 is also shifted to the “transient operation mode” and decelerated even when the deceleration fuel cut (fuel cut) execution condition is satisfied in the “steady operation mode” (T13). The decelerated engine 15 returns from the fuel cut in the operation region and returns to the “steady operation mode” (T14).
FIG. 7 is a flowchart for explaining the control contents of the engine 15 mainly executed by the operation of the FI controller 70. The FI controller 70 is repeatedly executed while the main switch 34 is turned on and the power is turned on. The process to do is shown. The FI controller 70 detects the engine temperature from the output of the temperature sensor 48 (step S1. Function as the engine temperature detecting means of the FI controller 70), and detects the brake state from the outputs of the brake switches 57 and 58 (step S2). The accelerator command value and the actual throttle opening (actual throttle opening) are detected from the output of the accelerator operation amount sensor 32 and the output of the throttle position sensor 46 (given via the throttle controller 42) (step S3). The output of the magnet sensor 55 is processed to determine the vehicle speed (step S4). Further, the FI controller 70 detects the engine state that changes as described with reference to FIG. 6 (step S5). Specifically, the FI controller 70 refers to the state data stored in the state management memory.

Next, the FI controller 70 refers to the state data to determine whether the engine 15 is stopped (step S6). If the engine 15 is not stopped, it is determined whether or not the engine 15 should be stopped by executing idle stop (step S7). Details of this processing will be described later.
If it is determined that the idling stop should not be executed, the FI controller 70 refers to the output signal of the crank angle sensor 54 to determine the engine speed, and determines whether the engine speed is equal to or higher than the complete explosion determination speed. (Step S8). While this determination is denied during cranking, when the explosion starts, the engine speed becomes equal to or higher than the complete explosion determination speed.

  If it is determined that the engine speed is equal to or higher than the complete explosion determination speed and therefore the engine has been started (YES in step S8), then the FI controller 70 determines whether the engine 15 is idling (step). S9, S10). That is, the FI controller 70 refers to the output signal of the magnet sensor 55 as a vehicle speed sensor to determine whether the vehicle speed is a predetermined value (for example, 1 km / h) or less, that is, whether the two-wheeled vehicle 1 is stopped ( Step S9). If the vehicle is stopped (YES in step S9), the FI controller 70 further determines whether or not the accelerator command value detected in step S3 indicates a throttle opening greater than a predetermined idle throttle opening ( Step S10). If the accelerator command value corresponds to a throttle opening less than the idle throttle opening (NO in step S10), it is considered that the driver is substantially not operating the accelerator and is in the idling state. judge. In this case, idling control processing is executed (steps S11, S12, S13).

  That is, the FI controller 70 calculates the combustion injection amount, the injection timing, and the ignition timing at idling (step S11), and controls the injector 60 with a command value corresponding to the calculated fuel injection amount and injection timing. In addition, the ignition coil 61 is controlled so as to be ignited at the calculated ignition timing (step S12). Further, the FI controller 70 gives a throttle opening command value indicating that the throttle opening should be set to the idle throttle opening θid to the throttle controller 42 (step S13). Thereafter, the processing is returned, and the processing from step S1 is performed.

  When it is determined that the two-wheeled vehicle 1 is stopped (YES in step S9) and the accelerator command value indicates a throttle opening greater than the idle throttle opening (YES in step S10) This is a case where the driver is about to start by operating the accelerator (the right grip portion 28). In this case, an engine output suppression process (step S14) is performed that suppresses the output of the engine 15 to be lower than the output corresponding to the accelerator command value under a certain condition. This engine output suppression process corresponds to the function of the FI controller 70 as engine output suppression means. Details of the engine output suppression process will be described later.

  On the other hand, when it is determined that the two-wheeled vehicle 1 is not stopped (NO in step S9), the FI controller 70 next determines the vehicle speed to be a predetermined value (for example, It is determined whether it is 7-8 km / h) or more (step S15). This condition is not satisfied immediately after starting or when the driver gets off and holds the handle 7 to move the two-wheeled vehicle 1. In this case, engine output suppression processing (step S14) is performed.

  If it is determined that the vehicle speed is equal to or higher than the predetermined value (YES in step S15), the engine output suppression process (step S14) is omitted, and the FI controller 70 determines the fuel in accordance with the accelerator command value and the engine speed. The injection amount, fuel injection timing and ignition timing are calculated (step S16). The FI controller 70 further controls the injector 60 with the calculated fuel injection amount and fuel injection timing, and controls the ignition coil 61 with the calculated ignition timing (step S17). Thus, the FI controller 70 functions as an ignition timing control means by executing the processes of steps S16 and S17.

  Further, the FI controller 70 gives the throttle opening command value to the throttle controller 42 in order to make the throttle opening follow the accelerator command value (step S18). Thereafter, the process is returned, and the processes from step S1 are repeated. By executing step S18, the FI controller 70 functions as throttle opening control means for controlling the throttle opening.

  After the engine output suppression process (step S14), the process from step S16 is performed. However, in the processing from step S16 after it is determined in step S15 that the vehicle speed is equal to or higher than the predetermined value, the fuel injection amount, the fuel injection timing, and the ignition timing are all set to normal values, whereas the engine When the process from step S16 is performed after the output suppression process (step S14), the ignition timing is set later than the normal time. Further, in the process of step S18 for causing the throttle opening to follow the throttle opening command value, the follow-up delay time is set to be longer after the engine output suppression process than in the normal case (YES in step S15). . In other words, the engine output suppression process (step S14) is for setting the ignition timing retardation larger than the normal time and setting the throttle opening follow delay time longer than the normal time under a certain condition. It is processing.

  On the other hand, if it is determined that the engine is stopped (YES in step S6), the FI controller 70 obtains the fuel injection amount, the fuel injection timing, and the ignition timing corresponding to the engine start in preparation for restart (see FIG. Step S19). Further, the FI controller 70 determines whether there is a start request (step S20). If there is no start request, the process returns and the processing from step S1 is repeated. The presence / absence of the start request is determined based on whether the starter switch 36 is operated or not, and whether or not the return condition from the idle stop state is satisfied. Details of this processing will be described later.

  If there is a start request (YES in step S20), the FI controller 70 gives a start command to the ISG controller 71 (step S21). Thereby, the ISG controller 71 starts the starter motor 18. Further, the FI controller 70 starts the fuel pump 62 (step S22), controls the injector 60 based on the fuel injection amount and the fuel injection timing set in step S19, and similarly at the ignition timing set in step S19. Based on this, the ignition coil 61 is controlled (step S23). Thus, the FI controller 70 functions as restart control means for restarting the engine 15 in the idle stop state by executing the processes of the steps S20 to S23.

  Also, the FI controller 70 performs a start time throttle opening setting process (step S25) for setting a start throttle opening, and sends a start time throttle opening control signal indicating the set start time throttle opening control signal to the throttle controller. 42 (step S26). As a result, the position of the throttle 45 is controlled to a position corresponding to the throttle opening at the start. This starting throttle opening is set without depending on the accelerator command value.

  Therefore, even when the driver performs an excessive accelerator operation at the time of starting the engine 15, it is possible to prevent a sudden increase in the engine speed immediately after the starting. Furthermore, since the optimal air-to-fuel ratio at the time of starting can be realized, the engine 15 can be started reliably and a lot of harmful components can be prevented from being contained in the exhaust gas. Further, when the return condition (1) (3) (4) or (5) such as the release of the brake is satisfied, for example, even when the accelerator command value corresponds to the throttle fully closed, the accelerator By setting a throttle opening larger than the command value (fully closed), an optimal air-fuel ratio can be reliably realized. As a result, an optimum air-to-fuel ratio can be obtained at the time of restart in any situation, so that good restartability can be realized and exhaust gas containing a large amount of harmful components can be suppressed or prevented.

In this way, the FI controller 70 executes the processes of steps S25 and S26, so that the throttle opening when returning from the idle stop state does not depend on the accelerator command value. ) To function as a restart throttle opening setting means.
After step S26, the process is returned, and the process from step S1 is repeated.

  If it is determined that the engine should be stopped by executing the idle stop while the engine is operating (NO in step S6) (YES in step S7), the FI controller 70 indicates that the engine is idle. A stop flag is set (step S27). Further, the FI controller 70 stops the fuel injection by the injector 60 (step S28), and stops the fuel pump 62 (step S29). The subsequent processing returns to step S1. The processing in steps S7 and S27 to S29 corresponds to the function of the FI controller 70 as engine stop control means.

During the cranking, the determination in step S8 is denied. In this case, the process proceeds to step S23, and the injector 60 continues based on the fuel injection amount, the fuel injection timing, and the ignition timing at the time of starting. Then, the ignition coil 61 is controlled, and the throttle 45 is controlled based on the throttle opening at the start.
FIG. 8A and FIG. 8B are flowcharts showing an example of a subroutine for idle stop execution determination in step S7 of FIG. When the idle stop execution determination process is started, it is first determined whether or not the engine 15 is in idle stop execution (idle stop mode) (step S701). This determination may be made based on whether the idle stop flag is set. If it is determined that the engine 15 is in idle stop execution, the process returns to the main routine (see FIG. 7) without performing the subsequent processing. At this time, the return value of the idle stop execution determination is “1” (represents idle stop execution). Actually, if the idle stop is being executed, it is determined in step S6 in FIG. 7 that the engine is being stopped. Therefore, the process in step S701 may be omitted.

  If it is determined in step S701 that the state of the engine 15 is not executing the idling stop, it is determined whether or not the engine temperature is equal to or higher than a predetermined value (step S702). Here, if it is determined that the engine temperature is equal to or higher than the predetermined value, an engine temperature flag is set (step S703). If it is determined in step S702 that the engine temperature is not equal to or higher than the predetermined value, the engine temperature flag is cleared (step S704). That is, the engine temperature flag is a flag that is set when the above-described idle stop execution condition (1) is satisfied.

  Thereafter, it is determined whether or not a travel flag is set (step S705). Here, when it is determined that the traveling flag is not set, it is determined whether or not the vehicle speed exceeds a predetermined value (step S706). If it is determined that the vehicle speed exceeds the predetermined value, a travel flag is set (step S707). That is, the travel flag is a flag that is set when the above-described idle stop execution condition (2) is satisfied by the vehicle speed once exceeding a predetermined value.

  On the other hand, if it is determined in step S705 that the travel flag is set, and after the processing in step S707 is completed, it is determined whether or not the vehicle speed is zero (0 km / h) (step S708). Here, when the vehicle speed is zero, a vehicle stop flag is set (step S709). If it is determined in step S708 that the vehicle speed is not zero, the vehicle stop flag is cleared (step S710).

  Thereafter, it is determined whether or not the engine 15 is in a starting state (operating state) and the engine speed is equal to or lower than a predetermined value (idle determination speed) (step S711). Here, if it is determined that the engine 15 is in the starting state and the engine speed is equal to or lower than the idle determination speed, it is determined whether the throttle 45 is fully closed (step S712). If it is determined in step S711 that the engine 15 is not in the starting state or the engine speed is not equal to or lower than the idle determination speed, the process of step S712 is omitted and the process jumps to step S716.

  If it is determined in step S712 that the throttle 45 is fully closed, it is determined whether or not the duration for which the throttle 45 has been fully closed after the vehicle speed has reached zero has reached a predetermined time. (Step S713). If it is determined that the duration has reached the predetermined time, the idle continuation flag is set and the continuation counter is cleared (step S714). The idle continuation flag is a flag indicating that the idle rotation state has continued for a predetermined time after the vehicle speed becomes zero. The continuation counter is a counter for elapse of the continuation time of the situation in which the vehicle speed is zero and the throttle 45 is fully closed and in the idle rotation state. The determination in step S713 is made based on the value of this continuation counter.

If it is determined in step S713 that the predetermined time has not elapsed since the vehicle speed became zero, the continuation counter is incremented (step S715). If it is determined in step S712 that the throttle 45 is not fully closed, the idle continuation flag is cleared and the continuation counter is cleared (step S716).
Therefore, the idle continuation flag satisfies the above-described idle stop execution conditions (5) and (6) when the vehicle speed is zero and the throttle 45 is fully closed and idle rotation continues for a predetermined time. This flag is set when

  Then, when any one of steps S714, S715, and S716 is completed, step S801 shown in FIG. 8B is executed to determine whether or not the brake is being applied. If it is determined that the brake is being applied, a brake flag is set (step S802). If it is determined in step S801 that the brake is not being applied, the brake flag is cleared (step S803). Therefore, by using the brake flag, it can be determined whether or not the above-described idle stop execution condition (4) is satisfied.

When the brake flag is set in step S802, it is determined whether or not the front brake is applied (step S804). If it is determined that the front brake is applied, a front brake flag is set (step S805).
After the front brake flag is set in step S805 or when it is determined in step S804 that the front brake is not applied, it is determined whether the rear brake is applied (step S806). If it is determined that the rear brake is applied, the rear brake flag is set (step S807).

  After step S807 or step S803, or if it is determined in step S806 that the rear brake is not applied, it is determined whether the battery voltage is equal to or higher than a predetermined value (step S808). Here, when it is determined that the battery voltage is equal to or higher than a predetermined value, a voltage check flag is set (step S809). If it is determined in step S808 that the battery voltage is not equal to or higher than the predetermined value, the voltage check flag is cleared (step S810). That is, the voltage check flag is set when the aforementioned idle stop execution condition (3) is satisfied.

  When the process of step S809 or step S810 is completed, it is determined whether or not the idle stop execution conditions (1) to (6) are satisfied (step S811). That is, it is determined whether the engine temperature flag, the running flag, the voltage check flag, the brake flag, and the idle continuation flag are all set. When it is determined that the idle stop execution conditions (1) to (6) are satisfied, the execution of the idle stop is permitted (step S812). That is, the return value of the idle stop execution determination is set to “1”. If it is determined in step S811 that the idle stop execution conditions (1) to (6) are not satisfied, the idle stop is not performed. That is, the return value of the idle stop execution determination is set to “0”.

When the return value of the idle stop execution determination is “1”, the FI controller 70 advances the process from step S7 to step S27 in FIG. 7 and executes a process for stopping the engine 15. Further, when the return value of the idle stop execution determination is “0”, the FI controller 70 advances the process from step S7 to step S8 in FIG.
FIG. 9 is a flowchart showing an example of a subroutine for idle stop return determination. This idle stop return determination is a part of the determination process in step S20 of FIG.

The FI controller 70 first determines whether or not the engine 15 is in idle stop execution (step S1201). This determination may be made based on whether the idle stop flag is set. If it is determined that the idle stop is not being executed, the process returns to the main routine of FIG.
If it is determined that the idle stop is being performed, it is determined whether or not the accelerator command value is equal to or greater than a predetermined value (a value corresponding to a predetermined throttle opening) (step S1202). If it is determined that the accelerator command value is greater than or equal to the predetermined value, the idle stop flag is cleared, a start request is generated (step S1203), and the process returns to the main routine. Thus, the engine 15 in the idle stop state can be restarted in response to the return condition (2) being satisfied by the driver's accelerator operation.

  If it is determined in step S1202 that the accelerator command value is not equal to or greater than the predetermined value, the FI controller 70 releases the brake based on the state of the brake switches 57 and 58 (detected in step S2 in FIG. 8). It is determined whether or not (step S1204). If it is determined that the brake has been released, the idle stop flag is cleared, a start request is generated (step S1205), and the process returns to the main routine. Thereby, in response to the return condition (1) being satisfied, the engine 15 in the idle stop state can be restarted.

  If it is determined in step S1204 that the brake is not released, the FI controller 70 determines whether the battery voltage is equal to or lower than a predetermined value (step S1206). If it is determined that the battery voltage is equal to or lower than the predetermined value, the idle stop flag is cleared, a restart request is generated (step S1207), and the process returns to the main routine. Thereby, in response to the return condition (5) being satisfied, the engine 15 in the idle stop state can be restarted.

  If it is determined in step S1206 that the battery voltage is not lower than the predetermined value, the FI controller 70 determines whether the starter motor 18 is rotating (step S1208). If it is determined that the starter motor 18 is rotating, the FI controller 70 clears the idle stop flag, generates a restart request (step S1209), and returns the process to the main routine. Thus, in response to the return condition (3) being satisfied, the engine 15 in the idle stop state can be restarted.

If it is determined in step S1208 that the starter motor 18 is not rotating, the FI controller 70 determines whether the engine temperature detected in step S1 in FIG. 7 is below a predetermined value (step S1208). S1210). If it is determined that the engine temperature is lower than the predetermined value, the FI controller 70 clears the idle stop flag, generates a restart request (step S1211), and returns the process to the main routine. Thereby, in response to the return condition (4) being satisfied, the engine 15 in the idle stop state can be restarted.

In step S1210, when it is determined that the engine temperature is not lower than the predetermined value, and therefore it is determined that none of the return conditions (1) to (5) is satisfied, the idle stop flag is held in the set state. Then, the process returns to the main routine while the idle stop state is maintained.

  FIG. 10 is a flowchart for explaining the starting throttle opening setting process in step S25 of FIG. The FI controller 70 refers to the engine temperature detected in step S1 of FIG. 7 (step S41). Based on the engine temperature, the FI controller 70 calculates a throttle opening correction value Δθt (step S42). For example, the FI controller 70 holds a table in which a throttle opening correction value Δθt corresponding to the engine temperature is determined in advance in a memory provided therein, and the throttle opening correction value Δθt is obtained by referring to this table. It may be determined. Based on the throttle opening correction value Δθt, the FI controller 70 sets the starting throttle opening θst according to the following equation (step S43).

θst = θstn + Δθt
However, θstn represents the minimum throttle opening when the engine 15 is in a warm-up state. In this embodiment, the minimum throttle opening θstn during the warm-up operation is set larger than the idle throttle opening θid (the throttle opening during idling).
FIG. 11 is a diagram showing an example of the relationship between the engine temperature and the starting throttle opening θst. The starting throttle opening degree θst is set to a value between the warm-up minimum throttle opening degree θstn and the upper limit value θu corresponding to the throttle opening degree when the engine 15 is in the cold state. In other words, the throttle opening correction value Δθt is determined so that the starting throttle opening θst does not exceed the upper limit value θu. The upper limit value θu is set lower than the throttle opening corresponding to the transmission rotational speed at which the centrifugal clutch 24 transmits the driving force of the engine 15 to the drive pulley 22. Therefore, the centrifugal clutch 24 does not clutch in when the engine is started.

  In the example of FIG. 11, in the engine temperature range equal to or less than the threshold value Trt (predetermined value compared with the engine temperature) related to the return condition (4) from the idle stop state, the starting throttle opening θst is the upper limit value. It is determined to θu. Further, for engine temperature exceeding the threshold value Trt, the temperature decreases linearly as the engine temperature increases within a range up to the predetermined temperature T1, and the warm-up minimum throttle opening θstn is reached at the predetermined temperature T1. In addition, the throttle opening degree θst at the start is determined. That is, the lower the engine temperature, the larger the starting throttle opening θst. The warm-up operation minimum throttle opening θstn is applied to the engine temperature in the range exceeding the predetermined temperature T1. Ts is a threshold value corresponding to the idle stop execution condition (1) related to the engine temperature. In this example, the engine temperature threshold value Ts for executing the idle stop is set to be higher than the engine temperature threshold value Trt for returning from the idle stop state.

  FIG. 12 is a diagram showing another example of the relationship between the engine temperature and the starting throttle opening θst. In this example, the starting throttle opening degree θst monotonously decreases from the upper limit value θu to the warm-up minimum throttle opening degree θstn as the lower limit value within a range up to a predetermined temperature T2 as the engine temperature increases. It is stipulated in. The upper limit value θu is a value lower than the throttle opening corresponding to the transmission rotational speed at which the centrifugal clutch 24 transmits the driving force of the engine 15 to the drive pulley 22 as in the case of FIG.

  In this embodiment, at the time of engine start, regardless of the accelerator command value, the start time throttle opening θst as shown in FIG. 11 or FIG. 12 is set. Therefore, when the engine is started, including when returning from the idle stop state, the throttle opening is controlled to a value that ensures an appropriate air-fuel ratio. Thereby, startability (including restartability) can be improved, and exhaust of exhaust gas containing a lot of harmful components can be suppressed or prevented.

  More specifically, for example, even when the driver performs an excessive accelerator operation, the throttle opening is kept small, and an appropriate air-to-fuel cost is reliably achieved. Of course, the rotational speed of the engine 15 immediately after starting does not increase rapidly. Moreover, even when the upper limit value θu of the throttle opening θst at the time of start is applied, the centrifugal clutch 24 does not engage. Thereby, the two-wheeled vehicle 1 does not start unexpectedly and does not give the driver unpleasant feeling.

  Further, for example, when the engine 15 in the idle stop state is restarted by the release of the brake (return condition (1)), generally, the accelerator operation amount is substantially zero, and the throttle opening corresponding to this is reduced. The degree is fully closed. In such a case, a throttle opening larger than fully closed is appropriately set according to the engine temperature, and an appropriate air-to-fuel ratio that can reliably restart the engine 15 can be realized.

  The same applies when the engine 15 in the idling stop state is restarted due to other return conditions (3) to (5), and an appropriate throttle opening corresponding to the engine temperature is set regardless of the accelerator command value. Thus, an appropriate air-fuel ratio that can reliably restart the engine 15 is achieved. FIG. 13 is a flowchart for explaining the engine output suppression process in step S14 of FIG. The FI controller 70 first determines the throttle opening corresponding to the accelerator command value (detected by the accelerator operation amount sensor 32) corresponding to the driver's accelerator operation and the actual throttle opening (detected by the throttle position sensor 46). A deviation (hereinafter referred to as “throttle opening deviation”) is obtained, and it is determined whether the throttle opening deviation is equal to or less than a predetermined threshold value E1 (step S51). When the throttle opening deviation is equal to or less than the threshold value E1, that is, when the throttle opening corresponding to the accelerator command value is close to the actual throttle opening, the main routine is not performed without performing the subsequent processing. Then, the process from step S16 is performed.

  For example, when the driver performs a large accelerator operation and the return condition (2) from the idle stop state is satisfied, the throttle opening corresponding to the accelerator command value is a large value. The throttle opening θst is set to a smaller value. In such a situation, the throttle opening deviation exceeds the threshold value E1 (NO in step S51).

  In this case, in order to delay the ignition timing of the engine 15 from the normal and suppress the output of the engine 15 to be smaller than the output corresponding to the accelerator command value, an ignition timing retardation correction amount calculation process is performed (step S52). ). The ignition timing retardation correction amount calculated here is applied to the process in step S16 of FIG. 7 when returning to the main routine. That is, when calculating the ignition timing, the FI controller 70 corrects the ignition timing to be later than the normal ignition timing by the calculated ignition timing retardation correction amount. When the ignition timing is calculated in step S16 without passing through the processing in step S52, the ignition timing is calculated with the ignition timing retardation correction amount being zero. Therefore, the normal ignition timing is set.

  Following the ignition timing retardation correction amount calculation process (step S52), the throttle opening deviation is compared with a threshold value E2 (> E1) (step S53). If the throttle opening deviation is less than or equal to the threshold value E2 (YES in step S53), the process returns to the main routine and the processing from step S16 in FIG. 7 is performed. That is, the engine output is suppressed by correcting the ignition timing retardation.

  On the other hand, when the throttle opening deviation exceeds the threshold value E2 (NO in step S53), a follow-up delay time for causing the throttle opening to follow the accelerator command value is set (step S54). The follow-up delay time in this case is a time until the actual throttle opening reaches the throttle opening corresponding to the accelerator command value when the accelerator command value is maintained at a constant value. Normally, this follow-up delay time is set to a small value so as to enhance the responsiveness to the accelerator operation. However, in the process in step S54, the follow-up delay time is set larger than the normal time to slow down the responsiveness. This is a follow-up delay process. That is, in a situation where there is a large deviation between the throttle opening corresponding to the accelerator command value and the actual throttle opening, and the vehicle is running at a low speed (NO in step S15), the throttle opening is quickly set to the accelerator command value. If it follows, it will be in a sudden start state or a rapid acceleration state, which may give the driver discomfort and anxiety. Accordingly, in step S54, a relatively long follow-up delay time is set. After setting the follow-up delay time, the process returns to the main routine and the processing from step S16 in FIG. 7 is performed.

  In step S18 of FIG. 7, the FI controller 70 sets the throttle controller 42 to cause the throttle opening to follow the throttle opening corresponding to the accelerator command value based on the set following delay time. If the processing in step S54 has not been performed, the follow-up and delay time are set to small values, and the throttle opening immediately follows the accelerator command value.

  FIG. 14 is a diagram for explaining an example of the ignition timing retardation correction amount set by the ignition timing retardation correction amount calculation processing in step S52 of FIG. In the range where the throttle opening deviation is less than or equal to the threshold value E1, the ignition timing retardation correction amount is zero. In the range where the throttle opening deviation exceeds the threshold value E1, the ignition timing retardation correction amount is set so that it increases monotonously in the range up to the upper limit value Idy as the throttle opening deviation increases. In the example of FIG. 14, the ignition timing retardation correction amount reaches the upper limit value Idy at the threshold E2, but the throttle opening deviation exceeding the threshold E2 or the throttle opening deviation smaller than the threshold E2 , The ignition timing retardation correction amount may reach the upper limit value Idy. Further, as shown by the solid line in FIG. 14, the ignition timing retardation correction amount may be monotonously increased in a polygonal line as the throttle opening deviation increases, or as shown by the broken line in FIG. As the degree deviation increases, the ignition timing retardation correction amount may increase linearly (linearly) monotonously.

  Thus, by delaying the ignition timing from the normal ignition timing, it is possible to suppress the engine output, to suppress a rapid increase in the rotational speed immediately after the engine 15 is started, and to suppress sudden start and rapid acceleration. When the throttle opening deviation is equal to or less than the threshold value E1, sudden start or acceleration that causes discomfort to the driver does not occur without performing ignition timing retardation correction. On the other hand, if the throttle opening deviation threshold value E2 or less, if only the ignition timing retardation correction is performed, the sudden start or the sudden start may cause the driver to feel uncomfortable without performing the follow-up delay process (step S54). Acceleration can be prevented.

  FIG. 15 shows a setting example of the follow delay time when the throttle opening is made to follow the accelerator command value when the throttle opening deviation is larger than the threshold value E2 (NO in step S53 in FIG. 13). FIG. The follow-up delay time determined in step S54 is set longer as the throttle opening deviation is larger. FIG. 15 shows an example in which the follow-up delay time corresponding to a certain throttle opening deviation is determined depending on the vehicle speed. Yes. In this example, as the vehicle speed increases, the follow-up delay time is shortened, the response in the low speed region is blunted, and the responsiveness in the high speed region is enhanced.

  When the follow-up delay process in step S54 is not performed, the follow-up delay time is set to the upper limit value Du as shown by the broken line in the range below the predetermined vehicle speed V1. On the other hand, when the throttle opening deviation is large and the follow-up delay process is performed in step S54, a follow-up delay time larger than the normal time is set in the low speed region below the predetermined vehicle speed V1, as indicated by the solid line. . The follow-up delay time when the processing in step S54 is not performed may be set to zero.

  FIG. 16 is a diagram showing an example of a time change of the throttle opening when the throttle opening deviation immediately after returning from the idle stop state exceeds the threshold value E2. The difference between the throttle opening at the start θst and the throttle opening corresponding to the accelerator command value (accelerator command equivalent value) exceeds the threshold value E2 immediately after the start. For this reason, the ignition timing retardation correction is performed, a relatively large follow-up delay time is set, and the throttle opening gradually increases from the starting throttle opening θst. When the throttle opening deviation is reduced to the threshold value E2, the process of step S54 is omitted, so that the follow-up delay time is set to be short, and substantially only the ignition timing retard correction process is different from the normal process. Become. Therefore, the throttle opening rises to a value corresponding to the accelerator command value relatively quickly. In this process, if the throttle opening deviation becomes equal to or less than the threshold value E1, or the vehicle speed becomes equal to or higher than the predetermined vehicle speed V1, the ignition timing retard correction is not performed, and the throttle opening is determined more quickly. Will follow.

  As described above, according to this embodiment, at the time of restart after idling stop, the starting throttle opening degree θst corresponding to the engine temperature is set regardless of the accelerator command value. That is, even when the accelerator command value is a large value, the engine output is suppressed to be smaller than the value corresponding to the accelerator command value. Therefore, the engine 15 is started at an appropriate starting throttle opening θst regardless of the accelerator operating state, so that the air-fuel ratio at the starting becomes appropriate, restartability can be improved, and exhaust gas can be improved. Harmful components mixed in can be reduced.

Immediately after the restart, the ignition timing retard correction and follow-up delay processing suppresses the engine output value to be smaller than the value corresponding to the accelerator command value, and the degree of suppression of the engine output is gradually relaxed. Go. Thereby, the engine output gradually follows the accelerator command value.
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form. For example, in the above-described embodiment, the two-wheeled vehicle 1 has been described as an example. However, the present invention can be applied to a four-wheeled vehicle. Further, in the above-described embodiment, the vehicle in which the engine output is controlled by the manually operated accelerator (the right grip portion 28) has been described. The present invention can be similarly applied to vehicles having the same.

  In the above embodiment, when the engine 15 is restarted in response to the accelerator operation (in the case of the return condition (2)), the condition is that the throttle opening deviation exceeds a predetermined threshold value E2. In step S54 in FIG. 13, a process for setting the throttle opening follow delay time to a longer time is performed. However, in response to the establishment of other return conditions (1), (3) to (5), the engine 15 is turned on. In the case of restarting, similar follow-up time delay control may be performed. For example, when the engine 15 is restarted in response to the release of the brake (return condition (1)), since the accelerator command value normally corresponds to the throttle fully closed, the restart throttle opening is the accelerator command value. It becomes larger than the value corresponding to (fully closed). Therefore, after the engine 15 is started, the throttle opening may be controlled so as to gradually decrease from the restart throttle opening to a value corresponding to the accelerator command value.

  In addition, various design changes can be made within the scope of the matters described in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 2 is an illustrative plan view for explaining a configuration related to a handle of the two-wheel vehicle. It is a block diagram which shows the structure relevant to control of the engine of the said two-wheeled vehicle. It is a figure which shows the execution conditions when carrying out an idle stop of an engine. It is a figure which shows the return conditions when canceling an idle stop and restarting an engine. It is a state transition diagram which shows the state transition of an engine. It is a flowchart for demonstrating the control content of FI controller which controls the said engine. It is a flowchart which shows an example of the subroutine for idle stop execution determination. It is a flowchart which shows an example of the subroutine for idle stop execution determination. It is a flowchart which shows an example of the subroutine for idle stop return determination. It is a flowchart for demonstrating the throttle opening setting process at the time of a start. It is a figure which shows an example of the relationship between engine temperature and the throttle opening at the time of starting. It is a figure which shows the other example of the relationship between engine temperature and the throttle opening at the time of start. It is a flowchart for demonstrating an engine output suppression process. It is a figure for demonstrating the example of a setting of the ignition timing retardation correction amount. It is a figure which shows the example of a setting of the follow-up delay time when making a throttle opening follow with respect to an accelerator command value. It is a figure which shows the example of the time change of the throttle opening immediately after returning from an idle stop state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Two-wheel vehicle 2 Body frame 3 Power unit 4 Rear wheel 5 Front fork 6 Front wheel 7 Handle 8 Rear cushion unit 9 Driver's seat 10 Passenger's seat 11 Footrest part 12 Front brake unit 13 Rear brake unit 15 Engine 16 Transmission case 17 Crankshaft 18 Starter Motor 19 Belt 20 Gear 21 Gear 22 Drive Pulley 23 Driven Pulley 24 Centrifugal Clutch 25 Belt 26 Handle Shaft 27 Left Grip Portion 28 Right Grip Portion (Manually Operated Accelerator)
29 Rear brake lever 30 Front brake lever 31 Handle cover 32 Accelerator operation amount sensor 34 Main switch 35 Instrument panel 36 Starter switch 37 Speedometer 38 Fuel gauge 40 Intake pipe 41 Electric motor 42 Throttle controller 43 Intake pipe negative pressure sensor 45 Throttle 46 Throttle Position sensor 48 Temperature sensor 51 Cam shaft 52 Cam sensor 54 Crank angle sensor 55 Magnet sensor 57 Front brake switch 58 Rear brake switch 60 Injector 61 Ignition coil 62 Fuel pump 70 FI controller 71 ISG controller 72 ISG
75 battery

Claims (10)

An engine having a throttle driven by an electric motor and generating a driving force for driving the wheels;
Engine startability detecting means for detecting a predetermined physical quantity that affects the starting characteristics of the engine;
An accelerator that is operated by a driver to control the output of the engine and generates an accelerator command value corresponding to an operation amount;
Engine output control means for controlling engine output based on an accelerator command value generated from the accelerator,
The engine output control means
Engine stop control means for stopping the engine in response to satisfaction of a predetermined engine stop condition;
Restart control means for restarting the engine stopped by the engine stop control means in response to a predetermined restart condition being satisfied;
Throttle opening control means for controlling the throttle opening by controlling the electric motor based on an accelerator command value from the accelerator;
When the engine is restarted by the restart control means, the throttle opening degree control means depends on the physical quantity detected by the engine startability detection means without depending on the accelerator command value. A vehicle including restart throttle opening setting means for setting a restart throttle opening. The engine startability detecting means includes engine temperature detecting means for detecting the temperature of the engine,
The vehicle according to claim 1, wherein the restart throttle opening setting means determines the restart throttle opening according to an engine temperature detected by the engine temperature detection means.   The restart throttle opening setting means sets the restart throttle opening larger than the throttle opening corresponding to the accelerator command value in accordance with the physical quantity detected by the engine startability detecting means. The vehicle according to claim 1, wherein the vehicle is a vehicle.   The throttle opening control means, after restarting the engine, from a restart throttle opening set by the restart throttle opening setting means to a throttle opening corresponding to an accelerator command value generated by the accelerator. The vehicle according to any one of claims 1 to 3, wherein the throttle opening is gradually changed.   The vehicle according to any one of claims 1 to 4, wherein the accelerator is a manually operated accelerator that a driver operates by hand. An engine control device for a vehicle, which is controlled by an accelerator operation and drives wheels by an engine having a throttle driven by an electric motor,
Engine startability detecting means for detecting a predetermined physical quantity that affects the starting characteristics of the engine;
Engine stop control means for stopping the engine in response to satisfaction of a predetermined engine stop condition;
Restart control means for restarting the engine stopped by the engine stop control means in response to a predetermined restart condition being satisfied;
Throttle opening control means for controlling the throttle opening by controlling the electric motor based on an accelerator command value from the accelerator;
When the engine is restarted by the restart control means, the throttle opening degree control means depends on the physical quantity detected by the engine startability detection means without depending on the accelerator command value. An engine control device comprising restart throttle opening setting means for setting a restart throttle opening. The engine startability detecting means includes engine temperature detecting means for detecting the temperature of the engine,
The engine control apparatus according to claim 6, wherein the restart throttle opening setting means determines the restart throttle opening according to an engine temperature detected by the engine temperature detection means.   The restart throttle opening setting means sets the restart throttle opening larger than the throttle opening corresponding to the accelerator command value in accordance with the physical quantity detected by the engine startability detecting means. The engine control apparatus according to claim 6 or 7, wherein   The throttle opening control means, after restarting the engine, from a restart throttle opening set by the restart throttle opening setting means to a throttle opening corresponding to an accelerator command value generated by the accelerator. 9. The engine control device according to claim 6, wherein the throttle opening is gradually changed. An engine control method for a vehicle that is controlled by an accelerator operation and drives wheels by an engine having a throttle driven by an electric motor,
An engine startability detecting step of detecting a predetermined physical quantity that affects the start characteristics of the engine;
An engine stop step for stopping the engine in response to a predetermined engine stop condition being satisfied;
A restart step for restarting the engine that has been stopped by the engine stop step in response to a predetermined restart condition being satisfied;
When the engine is restarted by this restarting step, the throttle opening is set so that the restart throttle opening according to the physical quantity detected by the engine startability detecting means does not depend on the accelerator command value. An engine control method comprising: controlling the electric motor so as to obtain a degree.

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