JP5513881B2 - Engine control method - Google Patents

Description

The present invention relates to Rue engine control method to change the engine output by controlling a plurality of engine control elements in accordance with the acceleration command from the driver.

  Generally, a reference value is determined in advance for the amount of fuel supplied to the engine in accordance with the engine speed, the throttle opening, and the like. A control device that controls the operation of the engine determines a fuel supply amount determined as a reference value based on the engine speed and throttle opening obtained from various sensors, and injects that amount of fuel into the intake air by the injector. To do. In an engine mounted on a vehicle in recent years, when the throttle is closed and decelerated, fuel cut control is performed to stop fuel injection to the engine to improve fuel consumption. There is provided one in which injection is resumed (see, for example, Patent Document 1).

JP-A-2005-76600

  However, during fuel cut control, the fuel adhering to the intake pipe before the fuel cut is sucked into the engine, and the intake pipe is in a dry state. Normally, in a motorcycle, the air-fuel ratio of the air-fuel mixture is set to a rich state. However, when fuel injection is resumed by opening the throttle for acceleration from the fuel cut control state, the injected fuel is dried. Therefore, the air-fuel mixture sucked into the engine is temporarily in a lean state and then in a rich state. Then, when the fuel injection is restarted and accelerated, the engine output fluctuates and drivability is impaired. In particular, during cornering, the driver becomes nervous with respect to vehicle body vibration and the like, so it is desirable to suppress engine output fluctuations that occur when fuel injection is resumed from the fuel cut control state.

  Further, when the throttle opening is small, the combustion energy is smaller than the mechanical resistance of the engine, so that the crankshaft is rotated by the power from the drive wheels, and the engine output becomes negative. In particular, when the throttle is closed for deceleration at a high engine speed during traveling, a state occurs in which the engine is not combusted due to insufficient intake air amount. When the throttle is opened for acceleration from this state, the engine suddenly shifts from the non-combustible state to the fuel state, the engine output fluctuates, and drivability is impaired.

  Accordingly, an object of the present invention is to improve drivability when shifting from a deceleration state to an acceleration state.

The engine control method of the present invention includes a fuel cut control process for controlling the fuel supply device to stop fuel supply to the engine when a predetermined fuel cut condition is satisfied during deceleration, and after the start of the fuel cut control process, When the braking command given by the driver is released, an output increase preparation step for preparing output increase by restarting fuel supply to the engine within a range where the non-combustion state in the combustion stroke of the engine is maintained ; after the start of power augmentation preparation step includes the acceleration command from the driver is input, and an output increase step of increasing the engine output.

  According to the method, it is possible to predict that the acceleration command is given from the driver before the acceleration command is input by determining the cancellation of the braking command in the deceleration control state. By doing so, engine control can be started in advance before the acceleration command is given, and the engine responsiveness is improved compared to the case where engine control is started after the acceleration command is given, or the engine output is suddenly changed. It can be prevented. As a result, drivability when shifting from the deceleration state to the acceleration state can be improved.

In the output increase preparation step, the fuel supply amount when resuming the fuel supply to the engine for each running state of the vehicle may be not different.

According to the method, it is possible to perform a suitable change in the control amount according to the traveling state, and to further improve the riding comfort. For example, in a traveling state where acceleration is desired to be accelerated, the control amount change in the output preparation step can be set so that the output increase amount in the output increase step becomes large. Further, in a traveling state in which it is desired to suppress a sudden output fluctuation in the output increasing process, the control amount change in the preparation process can be set so that the output increasing amount becomes small .

The output increase preparation step is performed after the elapse of a predetermined delay time from the time when it is determined that the braking command is released, and the delay time is determined as non-low fuel consumption travel when the low fuel consumption travel mode is set. It may be set longer than the mode.

  As is apparent from the above description, according to the present invention, drivability when shifting from the deceleration state to the acceleration state can be improved.

1 is a right side view showing a motorcycle according to a first embodiment of the present invention. FIG. 2 is a block diagram illustrating a control system for the motorcycle shown in FIG. 1. Fig. 3 is a flowchart for explaining control of the motorcycle shown in Fig. 2. It is a graph explaining the control shown in FIG. It is a flowchart explaining control of the motorcycle which concerns on a 1st reference form. It is a graph explaining the control shown in FIG. It is a flowchart explaining the control of the motorcycle which concerns on 2nd Embodiment of this invention. It is a graph explaining the control shown in FIG. It is a flowchart explaining control of the motorcycle which concerns on a 2nd reference form. It is a graph explaining the control shown in FIG. It is a flowchart explaining control of the motorcycle concerning a 3rd reference form.

  Embodiments according to the present invention will be described below with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and redundant description thereof is omitted. Moreover, the concept of the direction used in the following description is based on the direction seen from the driver who gets on the vehicle. In this embodiment, an example in which the present invention is applied to a motorcycle will be described. However, the present invention is applicable as long as the vehicle travels on wheels. For example, the present invention can be applied to any of a four-wheeled vehicle and a straddle-type vehicle that is driven by a driver straddling a seat. The saddle riding type vehicle includes a motorcycle, an ATV (All Terrain Vehicle), and the like.

  FIG. 1 is a right side view showing a motorcycle 1 according to a first embodiment of the present invention. As shown in FIG. 1, the motorcycle 1 includes a front wheel 2 that is a driven wheel and a rear wheel 3 that is a drive wheel. The front wheel 2 is rotatably supported by a lower end portion of a front fork 4 extending substantially in the vertical direction, and the front fork 4 is supported by a steering shaft (not shown) via a bracket (not shown). . A steering shaft (not shown) is rotatably supported by the head pipe 5. A bar-type handle 6 extending to the left and right is attached to the bracket.

  Front wheel brake discs 7 </ b> A are fixed to the left and right sides of the front wheel 2. A front wheel brake caliper 7 </ b> B is supported at the lower end of the front fork 4. The front wheel brake disc 7A and the front wheel brake caliper 7B constitute the front wheel brake 7, and a piston (not shown) of the front wheel brake caliper 7B is pressed against the front wheel brake disc 7A by hydraulic pressure to generate a braking force. A throttle grip 8 (acceleration input device) provided at a portion of the handle 6 that is gripped by the driver's right hand receives an acceleration command from the driver, and is rotated by a wrist twist to be described later. The device 22 (see FIG. 2) is operated. In front of the throttle grip 8, a brake lever 9 (braking input device) to which a braking command is input from a driver to mainly operate the front wheel brake 7 is provided.

  A pair of left and right main frames 10 extend rearward from the head pipe 5 while inclining downward, and a pair of left and right pivot frames 11 are connected to the rear portion of the main frame 10. The pivot frame 11 is pivotally supported by a front end portion of a swing arm 12 extending substantially in the front-rear direction, and the rear wheel 3 is rotatably supported by the rear end portion of the swing arm 12. A fuel tank 13 is provided behind the handle 6, and a seat 14 for riding a driver is provided behind the fuel tank 13. A rear brake disc 15A is fixed to the right side of the rear wheel 3. A rear wheel brake caliper 15 </ b> B is supported at the rear end of the swing arm 12. The rear wheel brake disc 15A and the rear wheel brake caliper 15B constitute the rear wheel brake 15, and a brake force is generated when a piston (not shown) of the rear wheel brake caliper 15B is pressed against the rear wheel brake disc 15A by hydraulic pressure. Let A step 16 on which the driver puts his / her foot is provided below the seat 14 and on both the left and right sides. A brake pedal 17 (braking input device) extending forward is pivotally supported on the right side step 16, and the rear wheel brake 15 can be mainly operated when the driver steps on the foot.

  An engine E is mounted between the front wheel 2 and the rear wheel 3 while being supported by the main frame 10 and the pivot frame 11. As the engine E, a four-stroke parallel four-cylinder engine is illustrated. A transmission 18 is connected to the output shaft of the engine E, and the driving force output from the transmission 18 is transmitted to the rear wheel 3 via a chain (not shown). A throttle device 22 (see FIG. 2) disposed inside the main frame 10 below the fuel tank 13 is connected to an intake port (not shown) of the engine E. An air cleaner 21 (see FIG. 2) disposed below the fuel tank 13 is connected to the upstream side of the throttle device 22 and is configured to take in outside air using traveling wind pressure from the front. An engine ECU 19 (engine control device) and an ABS ECU 20 are housed in the internal space below the seat 14.

  FIG. 2 is a block diagram illustrating a control system of the motorcycle shown in FIG. As shown in FIG. 2, the air cleaner 21 is connected to an intake port (not shown) of the engine E via a throttle device 22. The throttle device 22 has a throttle valve 23 that is disposed in the intake passage and adjusts the intake air amount. The throttle valve 23 is connected to a valve actuator 24 (engine control element) composed of a motor controlled by the engine ECU 19, and is opened and closed by the valve actuator 24. The throttle valve 23 is provided with a throttle position sensor 25 that detects the opening degree of the throttle valve 23.

  The throttle device 22 is provided with an injector 26 (engine control element) that is a fuel supply device that injects fuel into the intake passage. The engine E is provided with an ignition device 27 (engine control element) that ignites the air-fuel mixture in the four cylinders. The crankshaft (not shown) of the engine E is provided with an engine speed sensor 28 that detects the speed of the crankshaft. The engine E is connected to a transmission 18 for shifting the power of the engine E and transmitting it to the rear wheels 3. The transmission 18 is provided with a gear position sensor 29 for detecting the shift position. The throttle grip 8 is provided with a grip position sensor 30 that detects the opening of the throttle grip 8.

  The engine ECU 19 includes an arithmetic unit such as a microcomputer, various memories, and the like, and is connected to a throttle position sensor 25, an engine speed sensor 28, a gear position sensor 29, and a grip position sensor 30. The engine ECU 19 includes a main control unit 31, a throttle control unit 32, a fuel control unit 33, and an ignition control unit 34. The main control unit 31 performs calculations related to engine control based on signals input from the sensors 25, 28, 29, and 30. The throttle control unit 32 controls the valve actuator 24 based on the calculation result in the main control unit 31 and adjusts the opening degree of the throttle valve 23. The fuel control unit 33 controls the injector 26 based on the calculation result in the main control unit 31. The ignition control unit 34 controls the ignition device 27 based on the calculation result in the main control unit 31. The main control unit 31 is connected to an operation panel 35 for a driver to perform an input operation.

  The motorcycle 1 includes an electric brake device 36 that functions as an antilock brake system. The electric brake device 36 has an ABS ECU 20. Connected to the ABS ECU 20 are a front wheel speed sensor 37 for detecting the rotational speed of the front wheel 2 and a rear wheel speed sensor 38 for detecting the rotational speed of the rear wheel 3. Further, the ABS ECU 20 operates the front wheel brake actuator 39 including a hydraulic pump for operating the front wheel brake 7 (the front wheel brake caliper 7B) and the rear wheel brake 15 (the rear wheel caliper 15B). And a rear wheel brake actuator 40 including a hydraulic pump. The ABS ECU 20 includes a front wheel brake pressure sensor 41 (braking amount sensor) for detecting a brake pressure (hydraulic pressure) for operating the front wheel brake 7 (front wheel brake caliper 7B), and a rear wheel brake 15 (front wheel). A rear wheel brake pressure sensor 42 (braking amount sensor) for detecting a brake pressure (hydraulic pressure) for operating the brake caliper 7B) is connected. That is, the brake pressure sensors 41 and 42 serve to detect the braking amount of the braking command by the driver. As a braking amount sensor, a brake stroke sensor that detects an operation amount of the brake lever 9 or the brake pedal 17 may be used instead of the brake pressure sensor.

  FIG. 3 is a flowchart for explaining the control of the motorcycle 1 shown in FIG. FIG. 4 is a graph illustrating the control shown in FIG. Hereinafter, control when the engine E shifts from the fuel cut control state to the acceleration state will be described with reference to FIGS. First, when the engine E is started, normal operation is started (step S1). During the normal operation, the main control unit 31 of the engine ECU 19 determines whether or not a predetermined fuel cut condition (steps S1 to S3) is satisfied.

Specifically, first, it is determined whether or not the engine speed detected by the engine speed sensor 28 is equal to or higher than a predetermined value (for example, 2000 to 2500 rpm) (step S2). If Yes in step S2, it is determined whether or not the throttle grip opening φ detected by the grip position sensor 30 is in a fully closed state (zero or nearby) (step S3). When the throttle grip opening φ is in the fully closed state (zero or in the vicinity thereof), the throttle opening θ of the throttle valve 23 is controlled to be the idling opening θ ₁ . In the case of Yes in step S3, whether the brake pressure P detected by the front wheel brake pressure sensor 41 or the rear wheel brake pressure sensor 42 is the first threshold P ₁ or more is determined (step S4).

If Yes in step 4 (time t _{1 in} FIG. 4), it is determined that the fuel cut condition is satisfied, and fuel cut control is executed as a deceleration process (step S5). The fuel cut control is a deceleration control for forcibly stopping the fuel injection from the injector 26 into the intake passage and reducing the engine output. Thereby, useless fuel consumption during deceleration is reduced, and fuel consumption is improved and exhaust gas is reduced. Note that if the answer is No in any of Steps S2 to S4, the fuel cut control is not executed, the process returns to Step S1 and the normal operation is continued.

During the fuel cut control, whether the brake pressure P detected by the front wheel brake pressure sensor 41 or the rear wheel brake pressure sensor 42 is smaller than the second threshold value P ₂ is determined (Step S6). The second threshold value P ₂ is a value larger than the first threshold value P ₁ . However, the first threshold value P ₁ and the second threshold value P ₂ may be the same value. In the case of No in step S6, it is determined whether or not the engine speed detected by the engine speed sensor 28 is equal to or higher than a predetermined value (for example, 2000 to 2500 rpm) (step S7). The predetermined value in step S7 may be the same as or different from the predetermined value in step S2.

In the case of No in step S7, since the engine speed is low and engine stall is likely to occur, the normal operation is resumed and fuel injection is resumed (step S1). In the case of Yes in step S7, the process returns to step S5, again, whether the brake pressure P is smaller than the second threshold value P ₂ is determined (Step S6). If Yes at step S6 (time t ₂ in FIG. 4), determines that the braking command is canceled, it determines the delay time T (step S8). The delay time T is a time from when it is determined Yes in step S6 to when fuel injection is restarted. As a result, fuel efficiency can be improved as compared with the case where fuel injection is restarted at the same time when it is determined that the braking command is released.

Next, it is determined whether or not the delay time T has elapsed since it was determined that the braking command was released (step S9). In the case of Yes in step S9 (time t ₃ in FIG. 4), as the output increases preparing step, the throttle opening theta fuel injection by the injector 26 while idling opening theta ₁ is resumed (step S10). When restarting the fuel injection, the timing of restarting the fuel injection between the four cylinders of the engine E may be shifted. If it does so, the fluctuation | variation of the engine output at the time of accelerating after resumption of fuel injection will become smooth, and driving | operation feeling will improve more.

Next, it is determined whether or not an acceleration command has been input by the driver (step S11). Specifically, it is determined whether or not the throttle grip opening φ is greater than zero. In the case of Yes in step S11 (time t _{4 in} FIG. 4), the operation returns to the normal operation (step S1) as the output increasing process, and the throttle opening θ increases in conjunction with the increase in the throttle grip opening φ. Engine output increases.

  The delay time T determined in step S8 is determined according to the traveling state of the motorcycle 1. Specifically, the main control unit 31 of the engine ECU 19 stores a delay time map indicating the correlation between the value detected by the traveling state detection sensor and the delay time T. The traveling state detection sensor is, for example, at least one of the brake pressure sensors 41 and 42, the engine speed sensor 28, the front wheel speed sensor 37, and the gear position sensor 29.

  The delay time map indicates that the longer the brake pressure (braking amount) detected by the brake pressure sensors 41 and 42, or the greater the rate of change in brake pressure per unit time from the start of braking (ie, the quicker the brake), the longer the delay time. T can be set to be shorter. Further, the delay time map can be set so that the delay time T becomes shorter as the engine speed detected by the engine speed sensor 28 or the rate of change in the engine speed per unit time from the start of braking is larger. Further, the delay time map can be set such that the delay time T becomes shorter as the front wheel speed (that is, the traveling speed) detected by the front wheel speed sensor 37 increases.

  When the braking amount, the braking amount change rate, the engine speed, the rotational speed change rate, the traveling speed, or the traveling speed change rate are large, the traveling speed is greatly reduced due to deceleration. Many. Further, when the engine speed and the traveling speed are high, the total amount of intake air that is guided to the engine E during fuel cut control increases, so that the dryness of the inner wall of the intake passage increases. Therefore, by restarting the fuel injection by shortening the delay time T as the value of at least one of the braking amount, the braking amount change rate, the engine speed, the engine speed change rate, the travel speed, and the travel speed change rate increases. The time until the acceleration command is input from the time (when the output increase preparation is started) becomes longer, and sufficient fuel can be adhered to the inner surface of the pipe wall of the intake passage of the throttle device 22. Therefore, the air-fuel ratio of the air-fuel mixture at the time of acceleration command after the output increase preparation can be made rich, and quick acceleration with little output fluctuation can be obtained.

  Further, the delay time map indicates that the delay time is longer when the shift position detected by the gear position sensor 29 is the first speed position with the largest reduction ratio than when the shift position is the other shift position (2nd to 6th speed positions). T can be set to be long. When the transmission position of the transmission 18 is the first speed with a large reduction ratio, the generated torque is large. Therefore, when the shift position is the first speed, the delay time is made longer than the other shift positions, so that the time from when the fuel injection is resumed (when output increase preparation is started) until the acceleration command is input And the amount of fuel adhering to the inner surface of the pipe wall of the intake passage of the throttle device 22 can be prevented. Therefore, it is possible to suppress the torque from becoming excessively large at the time of reacceleration and realize stable acceleration.

  Further, the delay time map indicates that the delay time is longer when the shift position detected by the gear position sensor 29 is the first speed position with the largest reduction ratio than when the shift position is the other shift position (2nd to 6th speed positions). It can also be set so that T becomes shorter. When the speed change position of the transmission 18 is the first speed with a large reduction ratio, a sufficient acceleration force is often required. Therefore, when the shift position is the first speed, the delay time is made shorter than the other shift positions, so that the time from when the fuel injection is restarted (when the output increase preparation is started) until the acceleration command is input Therefore, the amount of fuel attached to the inner surface of the pipe wall of the intake passage of the throttle device 22 can be increased. Therefore, the torque at the time of reacceleration can be sufficiently increased to improve the acceleration performance. In addition, the delay time T is changed between the case where the shift position is the first speed and the case other than the first speed, but the case where the shift position is a group having a large reduction ratio (for example, the first and second speeds), The delay time T may be changed depending on the group having a small reduction ratio (for example, the third speed or higher).

  The delay time T is set to a time shorter than the time from when it is determined that the braking command is released until the acceleration command is input (this time is obtained experimentally). It may be set to a value not less than seconds and not more than 0.5 seconds. Further, the delay time T may be set by the driver operating the operation panel 35. In the present embodiment, the delay time T is variable according to the running state or the engine operating state, but may be constant regardless of the state. Further, the delay time map may be set so that the delay time T becomes longer when the low fuel consumption travel mode is set than when the non fuel efficient travel mode is set. Also, zero may be given as the delay time T.

  According to the configuration described above, the fuel injection to the engine E is resumed when it is determined that the braking command has been released during the fuel cut control, so the pipe of the intake passage that has been dried before the acceleration operation is performed. Fuel is attached to the wall inner surface in advance, and engine output fluctuations caused by air-fuel ratio fluctuations can be suppressed. As a result, it is possible to suppress engine output fluctuations while executing fuel cut control, and to achieve both improved fuel efficiency and improved drivability.

(First reference form)
FIG. 5 is a flowchart for explaining the control of the motorcycle according to the first embodiment. FIG. 6 is a graph illustrating the control shown in FIG. Hereinafter, control when the engine E shifts from the fuel cut control state to the acceleration state will be described with reference to FIGS. Steps S1 to S9 are the same as those in the first embodiment, and a description thereof will be omitted. In step S9, when it is determined that the delay time T has elapsed from the time when it is determined that the braking command is released (time t _{3 in} FIG. 6), the fuel injection by the injector 26 is resumed as an output increase preparation step. The throttle opening .theta. Is slightly increased without being made (step S20). When increasing the throttle opening θ, the timing at which the throttle opening θ starts to increase may be shifted between the four cylinders of the engine E.

Next, it is determined whether or not an acceleration command has been input by the driver (step S11). Specifically, it is determined whether or not the throttle grip opening φ is greater than zero. In the case of Yes in step S11 to return to the (time t ₄ in FIG. 6), the normal operation as the output increasing step (step S1), the the fuel injection by the injector 26 is resumed, in conjunction with the increase of the throttle grip opening degree φ As a result, the throttle opening θ increases and the engine output increases.

  According to the configuration described above, the throttle opening degree θ is increased when it is determined that the braking command is released during the fuel cut control, so that the intake air amount is increased in advance before the driver performs the acceleration operation. , The output responsiveness when the driver performs the acceleration operation is improved. By doing so, it is possible to prevent the engine output from increasing suddenly after the start of the acceleration operation, and to suppress engine output fluctuation. As a result, engine output fluctuations when shifting from the deceleration state to the acceleration state can be suppressed, and drivability can be improved. Since other configurations are the same as those of the first embodiment described above, description thereof is omitted.

( Second Embodiment)
FIG. 7 is a flowchart illustrating the control of the motorcycle according to the second embodiment of the present invention. FIG. 8 is a graph illustrating the control shown in FIG. Hereinafter, the control when the engine E shifts from the fuel cut control state to the acceleration state will be described with reference to FIGS. Steps S1 to S7 are the same as those in the first embodiment, and a description thereof will be omitted. In step S6, if the brake pressure P is determined to be smaller than the second threshold value P ₂ to determine the fuel injection amount F ₁ at (time t ₂ in FIG. 8), the output increases preparation (step S38).

The fuel injection amount F1 in the output increase preparation is determined according to the traveling state of the motorcycle 1. Specifically, the main control unit 31 of the engine ECU 19 stores an output increase preparation fuel injection amount map indicating a correlation between a value detected by the traveling state detection sensor and the fuel injection amount F ₁ . The traveling state detection sensor is, for example, at least one of the brake pressure sensors 41 and 42, the engine speed sensor 28, the front wheel speed sensor 37, and the gear position sensor 29.

The output increase preparation fuel injection amount map can be set so that the fuel injection amount F ₁ increases as the brake pressure or the brake pressure change rate detected by the brake pressure sensors 41 and 42 increases. Further, the output increase preparation fuel injection amount map can be set so that the fuel injection amount F ₁ increases as the engine speed detected by the engine speed sensor 28 increases. Further, the output increase preparation fuel injection amount map can be set so that the fuel injection amount F ₁ increases as the front wheel speed (that is, the traveling speed) detected by the front wheel speed sensor 37 increases.

  When the braking amount, the braking amount change rate, the engine speed, the rotational speed change rate, the traveling speed, or the traveling speed change rate are large, the traveling speed is greatly reduced due to deceleration. Many. Further, when the engine speed, the running speed, and the rate of change thereof are large, the total amount of intake air guided to the engine E during the fuel cut control increases, and thus the dryness of the inner wall inner surface of the intake passage increases. Therefore, the larger the value of at least one of the braking amount, the engine speed, the traveling speed, and the rate of change thereof, the larger the fuel injection amount F1 in the output increase preparation, thereby increasing the inner wall surface of the intake passage of the throttle device 22. Sufficient fuel can be deposited. Therefore, the air-fuel ratio of the air-fuel mixture at the time of acceleration command after the output increase preparation can be made rich, and quick acceleration with little output fluctuation can be obtained.

Further, the output increase ready fuel injection amount map indicates that when the shift position detected by the gear position sensor 29 is the first speed position with the largest reduction ratio, the shift position is the other shift position (2nd to 6th speed positions). The fuel injection amount F ₁ can be set to be smaller than that. When the transmission position of the transmission 18 is the first speed with a large reduction ratio, the generated torque is large. Therefore, when the speed change position is the first speed, the amount of fuel adhering to the inner surface of the pipe wall of the intake passage of the throttle device 22 is prevented by making the fuel injection amount F ₁ smaller than the other speed change positions. be able to. Therefore, it is possible to suppress the torque from becoming excessively large at the time of reacceleration and realize stable acceleration.

Further, the output increase ready fuel injection amount map indicates that when the shift position detected by the gear position sensor 29 is the first speed position with the largest reduction ratio, the shift position is the other shift position (2nd to 6th speed positions). Alternatively, the fuel injection amount F ₁ may be set to be larger. When the speed change position of the transmission 18 is the first speed with a large reduction ratio, a sufficient acceleration force is often required. Therefore, when the shift position is the first speed, the amount of fuel attached to the inner wall surface of the intake passage of the throttle device 22 can be increased by increasing the fuel injection amount F1 compared to the other shift positions. Acceleration performance during re-acceleration can also be improved.

Note that the fuel injection amount F1 is changed depending on whether the shift position is the first speed or a case other than the first speed, but the shift position is a group with a large reduction ratio (for example, first and second speeds). The fuel injection amount F1 may be changed depending on the group having a small reduction ratio (for example, the third speed or higher). Further, the fuel injection amount F ₁ may be set by the driver operating the operation panel 35. In the present embodiment, the fuel injection amount F1 is variable according to the running state or the engine operating state, but may be constant regardless of the state. Further, the output increase preparation fuel injection amount map may be set so that the fuel injection amount F1 decreases when the low fuel consumption travel mode is set.

Then, (time t ₃ in FIG. 8) Yes in the case at step S6, as the output increases preparing step, the throttle opening theta remains idling opening theta _1, the fuel injection amount F ₁ determined in step S38 Thus, the fuel injection by the injector 26 is resumed (step S39). When restarting the fuel injection, the timing of restarting the fuel injection between the four cylinders of the engine E may be shifted.

Next, it is determined whether or not an acceleration command has been input by the driver (step S11). Specifically, it is determined whether or not the throttle grip opening φ is greater than zero. If Yes at step S11 (time t ₄ in FIG. 8), the return to normal operation (step S1) as the output increasing step, the fuel injection by the injector 26 is performed normally based on the normal fuel injection amount map As the throttle grip opening φ increases, the throttle opening θ also increases and the engine output increases.

According to the configuration described above, the fuel injection amount F ₁ for the output increase preparation is adjusted according to the traveling state during the fuel cut control, so that the output can be performed so that re-acceleration suitable for the traveling state at that time can be performed. Increase preparation can be done. Since other configurations are the same as those of the first embodiment described above, description thereof is omitted. In the second embodiment, as in the first embodiment, in addition to the fuel injection amount, the delay time may be changed according to the running state and the engine operating state. By making it possible to change both the fuel injection amount and the delay time, control according to various states can be realized.

( Second reference form)
FIG. 9 is a flowchart for explaining the control of the motorcycle according to the second embodiment. FIG. 10 is a graph illustrating the control shown in FIG. Hereinafter, the control when the engine E shifts from the fuel cut control state to the acceleration state will be described with reference to FIGS. Steps S1 to S7 are the same as those in the first embodiment, and a description thereof will be omitted. If it is determined in step S6 that the brake pressure P is less than the second threshold value P ₂ (time t _{2 in} FIG. 10), the throttle opening θ ₂ in the output increase preparation is determined (step S48).

The throttle opening θ ₂ in the output increase preparation is determined according to the traveling state of the motorcycle 1. Specifically, the main control unit 31 of the engine ECU 19 stores an output increase preparation throttle opening map indicating a correlation between a value detected by the traveling state detection sensor and the throttle opening θ ₂ . The traveling state detection sensor is, for example, at least one of the brake pressure sensors 41 and 42, the engine speed sensor 28, the front wheel speed sensor 37, and the gear position sensor 29.

The output increase preparation throttle opening map can be set so that the throttle opening θ ₂ increases as the brake pressure or the brake pressure change rate detected by the brake pressure sensors 41 and 42 increases. Further, the output increase preparation throttle opening map can be set so that the throttle opening θ ₂ increases as the engine speed detected by the engine speed sensor 28 increases. Further, the output increase preparation throttle opening map can be set so that the throttle opening θ ₂ increases as the front wheel speed (ie, traveling speed) detected by the front wheel speed sensor 37 increases.

When the braking amount, the braking amount change rate, the engine speed, and the traveling speed are large, the traveling speed is greatly reduced. Therefore, it is often desired to accelerate quickly thereafter. Therefore, as the value of at least one of the braking amount, the braking rate change rate, the engine speed, and the traveling speed is larger, the throttle opening θ ₂ in the output increase preparation is increased so that the intake air that easily causes combustion in the cylinder is generated. The amount can be secured in advance. Therefore, the output responsiveness when the driver performs the acceleration operation is improved, and quick acceleration can be obtained.

In the output increase throttle opening map, when the shift position detected by the gear position sensor 29 is the first speed position where the reduction ratio is the largest, the shift position is the other shift position (2nd to 6th speed positions). Also, the throttle opening θ ₂ can be set to be small. When the transmission position of the transmission 18 is the first speed with a large reduction ratio, the generated torque is large. Therefore, when the speed change position is the first speed, by reducing the throttle opening θ ₂ as compared with the other speed change positions, it is possible to suppress the torque from becoming excessively large at the time of re-acceleration, thereby realizing stable acceleration. Can do.

In addition, the output increase preparation throttle opening map indicates that when the shift position detected by the gear position sensor 29 is the first speed position with the largest reduction ratio, the shift position is the other shift position (2nd to 6th speed positions). The throttle opening θ ₂ can also be set to be larger than that. When the speed change position of the transmission 18 is the first speed with a large reduction ratio, a sufficient acceleration force is often required. Therefore, when the speed change position is the first speed, the torque at the time of re-acceleration can be sufficiently increased and the acceleration performance can be improved by increasing the throttle opening θ ₂ more than the other speed change positions. .

The throttle opening θ ₂ may be set by the driver operating the operation panel 35. In the present embodiment, the throttle opening θ ₂ is variable, but may be constant. Further, the output increase preparation throttle opening degree map may be set so that the throttle opening degree θ ₂ becomes smaller when the low fuel consumption travel mode is set.

Then, (time t ₃ in FIG. 10) in the case of Yes in step S6, as the output increases preparatory step, while not resume fuel injection by the injector 26, the throttle opening to the throttle opening theta ₂ determined in step S48 The degree θ is increased (step S49). When increasing the throttle opening θ, the timing at which the throttle opening θ starts to increase may be shifted between the four cylinders of the engine E.

Next, it is determined whether or not an acceleration command has been input by the driver (step S11). Specifically, it is determined whether or not the throttle grip opening φ is greater than zero. In the case of Yes in step S11 to return to the (time t ₄ in FIG. 10), the normal operation as the output increasing step (step S1), the the fuel injection by the injector 26 is resumed, in conjunction with the increase of the throttle grip opening degree φ As a result, the throttle opening θ increases and the engine output increases.

According to the configuration described above, since the throttle opening θ ₂ for the output increase preparation is adjusted according to the traveling state during the fuel cut control, the output is performed so that re-acceleration suitable for the traveling state at that time can be performed. Increase preparation can be done. Since other configurations are the same as those of the first embodiment described above, description thereof is omitted. In the fourth embodiment, similarly to the first embodiment, in addition to the throttle opening, the delay time may be changed according to the traveling state and the engine operating state. By making it possible to change both the throttle opening and the delay time, control according to various states can be realized. Further, as in the second embodiment, in addition to the throttle opening, the fuel injection amount may be changed according to the state.

( 3rd reference form)
FIG. 11 is a flowchart for explaining the control of the motorcycle according to the third embodiment. Hereinafter, control when the engine E shifts from the deceleration state to the acceleration state will be described with reference to FIGS. That is, this embodiment does not relate to the control at the time of reacceleration from the fuel cut control state, but to the control at the time of reacceleration from the normal deceleration state.

  First, when the engine E is started, normal operation is started (step S1). During the normal operation, the main control unit 31 of the engine ECU 19 determines whether or not a predetermined deceleration condition (steps S2 and S3) is satisfied. Specifically, first, it is determined whether or not the engine speed detected by the engine speed sensor 28 is equal to or greater than a predetermined value (step S2). If Yes in step S2, it is determined whether or not the throttle grip opening φ detected by the grip position sensor 30 is in a fully closed state (zero or nearby) (step S3). If Yes in step S3, it is determined that the deceleration condition is satisfied, and deceleration control is executed as a deceleration process (step S55). In the deceleration control, the opening degree of the throttle valve 23 is reduced to the idling opening degree, and the fuel injection amount from the injector 26 into the intake passage is reduced to an amount suitable for the idling intake air amount to reduce the engine output. Control.

During the deceleration control, it is determined whether or not the brake pressure P detected by the front wheel brake pressure sensor 41 or the rear wheel brake pressure sensor 42 has become less than the second threshold value P ₂ since the first threshold value P ₁ or more. (Step S56). If No in step S56, the process returns to step S2. If Yes in step S56, it is determined that the braking command has been released, and the opening of the throttle valve 23 in preparation for increasing the output is determined (step S58). Then, as an output increase preparation step, the throttle opening θ is increased so that the throttle opening (opening slightly larger than the idling opening) determined in step S58 is performed without resuming the fuel injection by the injector 26. (Step S59). When increasing the throttle opening θ, the timing at which the throttle opening θ starts to increase may be shifted between the four cylinders of the engine E.

  Next, it is determined whether or not an acceleration command has been input by the driver (step S11). Specifically, it is determined whether or not the throttle grip opening φ is greater than zero. In the case of Yes in step S11, the operation returns to the normal operation (step S1) as the output increasing process, the fuel injection by the injector 26 is restarted, and the throttle opening θ increases in conjunction with the increase in the throttle grip opening φ. The engine output increases.

  According to the configuration described above, the opening of the throttle valve is increased when it is determined that the braking command is released during normal deceleration control. Therefore, the intake air amount is set in advance before the driver performs the acceleration operation. This increases the output response when the driver performs an acceleration operation. By doing so, it is possible to prevent the engine output from increasing suddenly after the start of the acceleration operation, and to suppress engine output fluctuation. As a result, engine output fluctuations when shifting from the deceleration state to the acceleration state can be suppressed, and drivability can be improved.

Also in control when reacceleration from normal deceleration state as in the present embodiment, as in the respective embodiments described above, may set the delay time T, the travel of the throttle opening degree at the output increased preparation It may be variable according to the state. Further, in the present embodiment, it is determined based on the brake pressure sensor that the braking command is released, but other means may be used. For example, the release of the braking command may be determined using a sensor that detects the brake lever displacement position. Further, it may be determined that the braking command has been released by determining that the deceleration change per unit time of the vehicle speed has reached substantially zero and that the deceleration change has become gradual. In the present embodiment, the brake release is determined using the first threshold value and the second threshold value, but one threshold value may be used. In this case, it may be determined that the braking has been released when the braking amount determination value reaches less than one predetermined value from a state where the braking amount determination value exceeds one predetermined value.

As described above, the engine control method according to the present invention has an excellent effect of improving the drivability when shifting from the deceleration state to the acceleration state, such as a motorcycle that can demonstrate the significance of this effect. It is beneficial to apply widely to saddle riding type vehicles.

1 Motorcycle 8 Throttle grip (acceleration input device)
9 Brake lever (braking input device)
17 Brake pedal (braking input device)
18 Transmission 19 Engine ECU (Engine Control Unit)
23 Throttle valve 24 Valve actuator (engine control element)
25 Throttle position sensor 26 Injector (fuel supply device, engine control element)
27 Ignition system (engine control element)
28 Engine speed sensor (running state detection sensor)
29 Gear position sensor (running state detection sensor)
30 Grip position sensor 36 Electric brake device (Anti-lock brake system)
37 Front wheel speed sensor (running state detection sensor)
41 Front wheel brake pressure sensor (braking amount sensor, running state detection sensor)
42 Rear wheel brake pressure sensor (braking amount sensor, running state detection sensor)
E engine

Claims (3)

A fuel cut control step for controlling the fuel supply device to stop the fuel supply to the engine when a predetermined fuel cut condition is satisfied at the time of deceleration;
When the braking command given by the driver is released after the start of the fuel cut control process, the fuel supply to the engine is resumed within the range where the non-combustion state in the combustion stroke of the engine is maintained, and the output is prepared for increase. An output increase preparation step, and
An engine control method comprising: an output increasing step of increasing an engine output when an acceleration command is input from a driver after the start of the output increasing preparation step. 2. The engine control method according to claim 1 , wherein in the output increase preparation step, a fuel supply amount at the time of resuming fuel supply to the engine is made different for each traveling state of the vehicle. The output increase preparation step is performed after elapse of a predetermined delay time from the time when it is determined that the braking command is released,
The engine control method according to claim 1 or 2 , wherein the delay time is set to be longer than that in the non-low fuel consumption travel mode when the low fuel efficiency travel mode is set.

Images