JP2010156205A - Engine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine control device without generating uncomfortable feeling to the operator at the time of changing an ignition timing in a normal running state in an engine comprising an electronically-controlled throttle. <P>SOLUTION: The device comprises a throttle sensor 15 for sensing the throttle opening sensing value, a crank angle sensor 17 for sensing the number of rotations of a crankshaft 9, a memory 21 for storing an optimum ignition timing and an ordinary ignition timing set according to the throttle opening degree and the number of rotations, and an ECU 20 for producing a command value for the engine ignition timing and throttle opening degree. The ECU 20 makes the ignition timing command value closer to the target value with the optimum ignition timing corresponding to the throttle opening degree and number of rotations sensed at the starting of the regular operation state regarded as an ignition timing target value, and it makes the throttle opening degree command value smaller for maintaining the regular operation state by restraining the output rise due to change of the ignition timing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an engine control device equipped with an electronically controlled throttle.

An engine that performs ignition timing control for bringing the ignition timing closer to the optimum efficiency ignition timing according to the engine speed is known (Patent Document 1). In the ignition timing control of Patent Document 1, not only the ignition timing is brought close to the optimum efficiency ignition timing, but also the control content is changed depending on the presence or absence of knocking vibration. For example, if it is determined that knocking has occurred in the engine, the ignition timing is retarded. Thereafter, if it is determined that knocking has not occurred, the ignition timing is gradually brought closer to the optimum efficiency ignition timing.
JP-A-5-26778

  The optimal efficiency ignition timing changes according to the engine speed. For this reason, it is necessary to change the ignition timing in accordance with changes in the engine speed. Here, if the ignition timing is controlled so as to always become the optimum efficiency ignition timing in accordance with the change in the rotational speed, knocking may easily occur in the fluctuation of the combustion state. Therefore, the normal ignition timing (normal ignition timing) is set to be retarded from the optimum efficiency ignition timing with a margin. Even in the low to medium load range where knocking does not occur, in many cases, the normal ignition timing is intentionally set to the retard side of the optimal efficiency ignition timing in order to emphasize driving ability (operability). Yes. The normal ignition timing is set so as to follow changes in the rotational speed and the throttle opening.

  In the steady running state in which the transition from acceleration / deceleration to steady running (constant speed running) has been completed, the variation range of the rotational speed is small. In this steady running state, there is little risk of knocking even if the ignition timing is controlled to the optimum efficiency ignition timing. Therefore, it is conceivable to control the ignition timing to the optimum ignition timing in the steady running state. However, when the ignition timing is optimized (changed from the normal ignition timing to the optimum efficiency ignition timing) in the steady running state, the engine output increases. Then, the operator of the vehicle on which the engine is mounted experiences an increase in the engine output despite not operating the throttle opening. This increase in output is felt by the operator as being uncomfortable.

  Further, when knocking occurs in the steady running state, the ignition timing is changed to the retard side in order to avoid knocking. At this time, the engine output decreases. Such a decrease in output is also felt as uncomfortable by the operator.

  That is, an object of the present invention is to provide an engine control device in which an operator does not feel uncomfortable when an ignition timing is changed in a steady running state in an engine equipped with an electronically controlled throttle.

  According to a first aspect of the present invention, there are provided throttle opening detection means for detecting the throttle opening of the engine, rotation speed detection means for detecting the rotation speed of the engine, the ignition timing of the engine and the command value of the throttle opening. A command value creating means to create, a storage means for storing a target ignition timing set according to the throttle opening and the rotation speed, and detecting whether or not the operating state of the engine is in a steady operating state. A steady operation state detecting means, wherein the steady operation state satisfies a condition that a fluctuation range of the rotational speed is maintained within a predetermined range, and the command value creating means is configured to include the steady operation state. When the state is detected, the output fluctuation suppression control is executed. The output fluctuation suppression control is performed by the throttle opening degree and the rotation speed detected when the steady operation state is started. The corresponding target ignition timing is set as the target value of the ignition timing, the command value of the ignition timing is brought close to the target value, and fluctuations in the output of the engine due to the change of the ignition timing are suppressed to maintain the steady operation state. In this control, the throttle opening command value is changed so as to be slanted.

  The first invention preferably employs the following configurations (a) to (f).

  (A) The control device further includes storage means for storing a normal ignition timing set according to the throttle opening and the rotation speed, and the normal ignition timing is at least in the operating state. The ignition timing set as a target value of the ignition timing when not in the steady operation state, the target ignition timing is an optimal ignition timing that is on the advance side of the normal ignition timing, and the output fluctuation Suppression control is optimum ignition timing control, and the optimum ignition timing control uses the optimum ignition timing corresponding to the throttle opening and the rotation speed detected when the steady operation state is started as the ignition timing. As a target value of the throttle, the throttle timing command value is brought close to the target value, and an increase in output due to the change of the ignition timing is suppressed to maintain the steady operation state. A control to reduce the time the command value.

  (B) The control device further includes a knocking detection means for detecting knocking of the engine, and a reference set on the retard side of the optimum ignition timing and according to the throttle opening and the rotational speed. Storage means for storing ignition timing, wherein the target ignition timing is the optimal ignition timing and the reference ignition timing, and the output fluctuation suppression control is optimal ignition timing control and knocking avoidance control, When the knocking is detected during the execution of the optimum ignition timing control, the command value creating means ends the optimum ignition timing control and performs the knocking avoidance control. Using the reference ignition timing corresponding to the throttle opening and the rotation speed detected when the steady operation state is started as a target value for the ignition timing, A command value of the ignition timing made closer to the target value, which is the control to increase the command value of the throttle opening such that the steady operation state is maintained by suppressing the output reduction due to the change of the ignition timing.

  (C) The command value creating means performs the optimum ignition timing control again when the steady operation state is detected after the knocking avoidance control is completed. The target value of the ignition timing in the subsequent optimal ignition timing control is set to the retard side by a predetermined correction angle from the target value in the previous optimal ignition timing control.

  (D) In the optimum ignition timing control or the knocking avoidance control, the command value creating means prevents the rotational speed from deviating from the predetermined range including the rotational speed when the steady operation state is started. The throttle opening command value is changed by feedback control according to the change of the ignition timing command value.

  (E) The steady operation state further satisfies the condition that the fluctuation range of the throttle opening is kept within a predetermined range.

  (F) The control device further includes gear ratio detection means for detecting a gear ratio in a gearbox that changes the output of the engine, and in the steady operation state, the gear ratio is a predetermined ratio. And the condition that the rotational speed is kept within a predetermined rotational speed range.

  According to the first invention of the present application, since the throttle opening is changed in conjunction with the change of the ignition timing, the occurrence of output fluctuation is suppressed. For this reason, the operator does not feel discomfort due to the output fluctuation.

  Furthermore, according to the configuration (a), the throttle opening is reduced in conjunction with the change of the ignition timing to the advance side so that the ignition is performed at the optimal ignition timing in the steady operation state. Occurrence is suppressed. For this reason, the operator does not feel discomfort due to the increase in output. In addition, since the ignition timing is controlled to the optimal ignition timing, the fuel efficiency of the engine is improved.

  Furthermore, according to the configuration (b), since the throttle opening is increased in conjunction with the change of the ignition timing to the retard side so that knocking can be avoided, the occurrence of a decrease in output is suppressed. For this reason, the operator does not feel a sense of incongruity due to a decrease in output. Moreover, occurrence of knocking can be avoided.

  Furthermore, according to the configuration (c), in the optimal ignition timing control after the occurrence of knocking, the target value of the ignition timing is set to the retard side with respect to the previous optimal ignition timing, so that knocking is difficult to occur. Thus, the ignition timing can be brought close to the optimal ignition timing. For this reason, fuel consumption can be improved while preventing knocking.

  Furthermore, according to the configuration (d), since the throttle opening command value is changed by feedback control based on the rotational speed in accordance with the change of the ignition timing command value, the throttle opening is changed according to the actual operating conditions. Command value can be changed. Therefore, it is possible to suppress the occurrence of output fluctuations regardless of changes in temperature conditions and fuel conditions. For this reason, the operator does not feel discomfort due to output fluctuation. Further, the fuel consumption of engine 100 can be improved.

  Furthermore, according to the configuration (e), the steady operation condition satisfies the condition that the fluctuation range of the throttle opening is kept within a predetermined range and the condition that the rotational speed is kept within a predetermined rotational speed range. Therefore, a more stable operation state becomes a steady operation state. For this reason, since output fluctuation suppression control is not performed in the transition period of the operating state, output fluctuation in the steady operating state is further suppressed.

  Furthermore, according to the configuration (f), since the steady operation condition satisfies the condition that the gear ratio is a predetermined ratio, a more stable operation state becomes the steady operation state. For this reason, since output fluctuation suppression control is not performed in the transition period of the operating state, output fluctuation in the steady operating state is further suppressed.

[Engine according to this embodiment]
An engine 100 according to an embodiment of the present invention will be described with reference to FIG.

  FIG. 1 shows an engine 100, an apparatus related to control of the engine 100 including an ECU (electric control unit) 20, and a throttle grip 30 and a brake 40 that are operating means. In the present embodiment, engine 100 is mounted on a motorcycle.

  As shown in FIG. 1, the engine 100 includes a cylinder 1, a piston 2, a combustion chamber 3, and a crankshaft 9. The combustion chamber 3 is formed by the cylinder 1 and the piston 2. The crankshaft 9 rotates in conjunction with the vertical movement of the piston 2.

  The engine 100 includes an intake port 4, an exhaust port 5, an intake valve 6, an exhaust valve 7, an intake pipe 11, and an exhaust pipe 12 as an intake and exhaust system configuration. The intake port 4 and the exhaust port 5 communicate with the combustion chamber 3. The intake valve 6 and the exhaust valve 7 are driven in conjunction with the crankshaft 9. The intake valve 6 opens and closes communication between the intake port 4 and the combustion chamber 3, and the exhaust valve 6 opens and closes communication between the exhaust port 5 and the combustion chamber 3. An intake pipe 11 is connected to the intake port 4 and an exhaust pipe 12 is connected to the exhaust port 5.

  The engine 100 includes a fuel injector 10 and a throttle valve 13 in an intake pipe 11. The throttle valve 13 changes the flow rate of air passing through the intake pipe 11 by changing the opening degree (throttle opening degree) in the intake pipe 11. Further, the fuel injector 10 generates an air-fuel mixture by supplying atomized fuel to the air passing through the downstream side of the intake pipe 11. The fuel supplied from the fuel injector 10 is changed according to the throttle opening, and the air-fuel ratio is maintained appropriately. Note that a fuel carburetor (fuel vaporizer) may be used instead of the fuel injector 10.

  The engine 100 includes a throttle motor 14. The throttle valve 13 is driven by the operation of the throttle motor 14, and the throttle opening is changed.

  The engine 100 includes a spark plug 8 and a booster 16. The spark plug 8 ignites the air-fuel mixture supplied into the combustion chamber 3 by electric discharge. The booster 16 supplies a high voltage to the spark plug 8.

  The throttle grip 30 is an operating means for an operator of the motorcycle to input a desired throttle opening to the ECU 20.

  The brake 40 is an operating means for an operator of the motorcycle to stop the motorcycle.

[Engine Control Device According to this Embodiment]
The control device for engine 100 includes various detection means and ECU 20. The ECU 20 is command value creation means for creating command values for the ignition timing and the throttle opening based on detection information from various detection means. The various detection means include a rotation speed detection means, a knocking detection means, a throttle grip operation amount detection means, a throttle opening degree detection means, a brake detection means, and a gear ratio detection means.

  The rotation speed detection means detects the rotation speed of the crankshaft 9. The rotational speed detection means is composed of a crank angle sensor 17 provided in the engine 100 and an ECU 20. The crank angle sensor 17 detects, for example, passage of teeth of a toothed rotor fixed to the crankshaft 9 and transmits a detection signal to the ECU 20. The ECU 20 detects the rotation angle of the crankshaft 9 and the rotation speed of the crankshaft 9 by counting the detection signals from the crank angle sensor 17.

  The knocking detection means is a knocking sensor 18 that detects the occurrence of knocking. The knocking sensor 18 is provided on the outer wall of the cylinder 1, for example. The knocking sensor 18 detects vibration generated between the cylinder 1 and the piston 2. The ECU 20 can detect the presence or absence of vibration (knocking vibration) having a magnitude greater than or equal to a predetermined value detected by the knocking sensor 18.

  The throttle grip operation amount detection means is a grip sensor 31 that detects the operation amount of the throttle grip 30. The grip sensor 31 is provided in the motorcycle corresponding to the throttle grip 30. The ECU 20 can detect the operation amount of the throttle grip 30 detected by the grip sensor 31.

  The throttle opening detection means is a throttle sensor 15 that detects the opening (throttle opening) in the intake pipe 11. The throttle sensor 15 is provided in the motorcycle corresponding to the throttle valve 13. The ECU 20 can detect the throttle opening detected by the throttle sensor 15.

  The brake detection means is a brake sensor 41 that detects the occurrence of an operation of the brake 40. The brake sensor 41 is provided on the motorcycle corresponding to the brake 40. The ECU 20 can detect the presence or absence of the operation of the brake 40 detected by the brake sensor 41.

  The transmission ratio detection means is a transmission ratio detection sensor 51 that detects a transmission ratio in the transmission 50. Here, the transmission 50 shifts and outputs the rotational speed of the crankshaft 9 as an input based on the set gear ratio. The transmission ratio in the transmission 50 is operated by a transmission lever (not shown). The ECU 20 can detect the gear ratio detected by the gear ratio detection sensor 51.

  The ECU 20 creates the command values for the ignition timing and the throttle opening, and controls the ignition timing and the throttle opening as follows.

  The ECU 20 controls the spark plug 8 via the booster 16. Basically, the ECU 20 creates a command value for the ignition timing (advance amount with respect to top dead center) in accordance with the rotational speed of the crankshaft 9. Then, the ECU 20 operates the booster 16 based on the ignition timing command value (that is, at the timing of the ignition timing created by itself). The spark plug 8 is activated by the operation of the booster 16. In this way, the actual ignition timing is controlled so as to coincide with the ignition timing command value created by the ECU 20.

  The ECU 20 controls the throttle opening degree via the throttle motor 14. Basically, the ECU 20 creates a command value for the throttle opening according to the operation amount of the throttle grip 30 and the driving situation according to a method similar to that of a normal electronic control throttle. Here, the driving situation indicates a gear ratio, a vehicle speed, an acceleration, and the like. Then, the ECU 20 operates the throttle motor 14 based on the throttle opening command value until the throttle opening command value matches the detected value. The opening degree of the throttle valve 14 is changed by the operation of the throttle motor 14. In this way, the actual throttle opening is controlled so as to coincide with the throttle opening command value created by the ECU 20. When output fluctuation suppression control (optimum ignition timing control and knocking avoidance control), which will be described later, is performed, a command value for the throttle opening is created by a method different from normal. Details will be described later.

[Ignition timing]
Next, the ignition timing will be described. The ignition timing is controlled by the ECU 20 creating a command value for the ignition timing so as to be changed or kept constant. The ignition timing needs to be changed according to the throttle opening and the rotational speed of the crankshaft 9. Generally, when the rotation speed of the crankshaft 9 increases, the ignition timing is advanced accordingly.

  FIG. 2 shows an example of point sequence data indicating the relationship between ignition timing and torque at a predetermined throttle opening and a predetermined rotation speed. The X axis represents the crank angle, and the Y axis represents the magnitude of the torque. The point sequence data includes an optimum efficiency ignition timing P, a knocking limit point K, a normal ignition timing N, and an optimum ignition timing F. The optimum efficiency ignition timing P is an ignition timing at the torque peak position in the point sequence data. The knocking limit point K is on the more advanced side than the optimum efficiency ignition timing P in the example of FIG. The normal ignition timing N is more retarded than the optimum efficiency ignition timing P and the knocking limit point K. The optimum ignition timing F is between the optimum efficiency ignition timing P and the normal ignition timing N on the retard side of the knock limit point K. Depending on the rotational speed, there may be a case where the knocking limit point K exists in the point sequence data on the retard side with respect to the efficiency optimum ignition timing P or there is no knocking limit point K.

  The optimal efficiency ignition timing P is an ignition timing at which the engine efficiency is theoretically maximized. The knock limit point K is an ignition timing at which knocking starts to occur. The normal ignition timing N is an ignition timing used in a normal operation state. The optimal ignition timing F is an ignition timing used in a steady operation state. Here, the steady operation state refers to a state in which, for example, the fluctuation range of the rotational speed of the crankshaft 9 is within a predetermined range, and the output of the engine 100 is kept substantially constant. On the other hand, the normal operation state refers to a state where the operating state of the engine 100 is not in a steady operation state, that is, an operation state in a transition period. For example, when accelerating or decelerating, it is a transition period and a normal operation state.

  The normal ignition timing N and the optimal ignition timing F are set as follows. The closer the ignition timing is to the torque peak (efficiency optimal ignition timing P), the better the engine efficiency. However, when the ignition timing approaches the torque peak, the following problem occurs. First, at the rotational speed at which the knocking limit point exists on the retard side of the efficiency optimum ignition timing P, knocking occurs due to the advance angle. Regardless of the presence or absence of the knocking limit point K, the operability in the transition period is deteriorated by the advance angle. Therefore, the normal ignition timing N is set on the retarded side of the torque peak with a margin of angle so that knocking can be avoided and sufficient operability in the transition period can be secured. On the other hand, the optimal ignition timing F is an ignition timing specialized for the steady operation state. That is, at the optimum ignition timing, the deterioration in operability during the transition period is ignored to some extent in order to bring the ignition timing closer to the torque peak. However, the optimal ignition timing F is also set so that knocking can be avoided. For this reason, the optimal ignition timing F is located between the optimal efficiency ignition timing P and the normal ignition timing N on the retard side of the knocking limit point K. When the knocking limit point K is on the advance side of the optimum efficiency ignition timing P, the optimum ignition timing F can coincide with the optimum efficiency ignition timing P.

[Ignition Timing Map Data According to this Embodiment]
The ignition timing map data used in the ignition timing control will be described.

  The ECU 20 includes a memory 21 that is a storage unit. The memory 21 stores map data of the ignition timing corresponding to the throttle opening and the rotational speed for each cylinder. For example, the ignition timing map data is two-dimensional array data based on the throttle opening and the rotational speed. Each cell of the two-dimensional array data stores an ignition timing corresponding to a predetermined range of the throttle opening and a predetermined range of the rotational speed. Based on such map data, the ECU 20 specifies an ignition timing that is appropriate for a specific throttle opening and a specific rotation speed.

[Ignition timing control according to this embodiment]
The ignition timing control according to the present embodiment will be described with reference to FIG. FIG. 3 is a diagram showing a time chart of ignition timing control. In FIG. 3, the detected value of the throttle opening by the throttle sensor 15, the detected value of the rotational speed of the crankshaft 9 by the crank angle sensor 17, the command value of the throttle opening by the ECU 20, and the command value of the ignition timing by the ECU 20 The graph of the time change is respectively shown about the result (ON, OFF) of the knocking determination by the knocking sensor 18.

  In FIG. 3, time T <b> 0 indicates the time when opening of the throttle opening is started by operating the throttle grip 30 after the engine 100 is started. At time T0, the detected value of the throttle opening is G0, the detected value of the rotational speed is R0, the command value of the throttle opening is TP0, the command value of the ignition timing is the normal ignition timing IN, and knocking The determination is OFF (none).

  From time T0 to time T1, the throttle grip 30 is operated so that the command value of the throttle opening increases. Along with this, the throttle opening increases. Further, the detected value of the rotational speed and the command value of the throttle opening increase with the increase of the detected value of the throttle opening. At time T1, the detected value of the throttle opening is G1, and the command value of the throttle opening is TPN.

  From time T1 to time T2, the throttle opening command value is substantially constant. During this time, the engine is in an accelerated state where the rotational speed increases. At time T2, the detected value of the rotational speed is R1. Note that the detected value of the throttle opening remains G1, and the command value of the throttle opening remains TPN between time T1 and time T2.

  After time T2, the detected value of the throttle opening is G1, which is a substantially constant value, and the detected value of the rotational speed is also maintained at R1, which is a substantially constant value. That is, after time T2, the operating state of engine 100 shifts from the normal operating state to the steady operating state.

  In FIG. 3, the detected value of the throttle opening, the command value of the throttle opening, and the detected value of the rotational speed are shown as substantially constant values. Actually, since the operator of the motorcycle operates the throttle grip 30, the operation amount of the throttle opening does not become a completely constant value but vibrates. As the operation amount varies, the detected value of the throttle opening, the command value of the throttle opening, and the detected value of the rotational speed also vary. Therefore, to be exact, the graph depicted in FIG. 3 vibrates up and down with the passage of time even in a straight line portion. In the definition of the steady operation state, one of the reasons for allowing the rotation speed to vary within a predetermined range is to ignore such vibrations that are not intended by the operator.

  When the operating state of engine 100 shifts to the steady operating state, ECU 20 executes output fluctuation suppression control. The output fluctuation suppression control of this embodiment includes optimum ignition timing control and knocking avoidance control.

  As the optimal ignition timing control, the ECU 20 advances the command value of the ignition timing from the normal ignition timing IN to the optimal ignition timing IM (target value) from time T2 to time T3, and sets the command value of throttle opening to TPN. To TP1 (target value). Here, the normal ignition timing IN and the optimal ignition timing IM are the normal ignition timing and the optimal ignition corresponding to the throttle opening command value TPN and the rotation speed detection value R1 detected when the steady operation state is started. It's time.

  In other words, the optimal ignition timing control is performed with the optimal ignition timing corresponding to the throttle opening and the rotational speed detected when the steady operation state is started as the ignition timing target value and the ignition timing command value as the target value. This is a control to reduce the command value for the throttle opening so that the steady operation state is maintained by suppressing the increase in output due to the change in the ignition timing.

  The optimal ignition timing control is control in consideration of the following points. First, an object is to maximize the output of the engine 100 at the same throttle opening and the same rotation speed by bringing the ignition timing closer to the optimum ignition timing. However, if the output increases without the throttle grip 30 being operated, the operator of the motorcycle will feel uncomfortable. Further, if there is no change in the magnitude of the load, the rotational speed increases as the output increases, so the steady operation state is impaired. On the other hand, if the throttle opening is reduced, the output of the engine 100 decreases. Therefore, it is possible to cancel the output increase caused by the optimization of the ignition timing (approaching the optimal ignition timing) by the output decrease by reducing the throttle opening. Note that it is not necessary to completely cancel the increase in output, and it is sufficient that the increase in output can be suppressed. As a result of such consideration, in the optimal ignition timing control, the throttle opening is controlled to be small in accordance with the optimization of the ignition timing so that the steady operation state is maintained.

  When the command value of the ignition timing reaches the optimal ignition timing IM, the ECU 20 controls the ignition timing so as to maintain the state. The time when the command value of the ignition timing reaches the optimal ignition timing IM is T4. After time T3, the ignition timing command value is maintained at the optimal ignition timing IM, and the throttle opening command value is maintained at TP1.

  At time T4 after time T3, knocking occurs and knocking determination is ON.

  When knocking is detected during execution of optimal ignition timing control, ECU 20 ends optimal ignition timing control and executes knocking avoidance control. The optimal ignition timing control is finished at time T5 immediately after time T4.

  As knocking avoidance control, the ECU 20 retards the command value of the ignition timing from the optimal ignition timing IM to the normal ignition timing IN (target value) from time T5 to time T6, and sets the throttle opening command value to TP1. To TPN (target value).

  That is, the knocking avoidance control is a command value for the ignition timing with the reference ignition timing (normal ignition timing) corresponding to the throttle opening and the rotation speed detected when the steady operation state is started as the target value of the ignition timing. Is controlled to increase the command value of the throttle opening so that the steady operation state is maintained by suppressing the output decrease due to the change of the ignition timing.

  The knocking avoidance control is control in consideration of the following points. First, in order to avoid knocking, the ignition timing is changed to the retard side with respect to the optimal ignition timing. In the present embodiment, the target value (reference ignition timing) of the ignition timing in the knocking avoidance control is the normal ignition timing that is retarded from the optimal ignition timing. The reference ignition timing may be any ignition timing that is retarded from the optimal ignition timing, and is not limited to the normal ignition timing. Further, if the ignition timing is changed, the same problem as in the case of the optimal ignition timing control occurs. That is, when the output is reduced in a state where the throttle grip 30 is not operated, the operator of the motorcycle feels uncomfortable. Moreover, a steady operation state will be impaired. Therefore, it is possible to cancel or suppress the output decrease caused by changing the ignition timing by increasing the output by increasing the throttle opening. As a result of such consideration, in the knocking avoidance control, the throttle opening is largely controlled according to the change of the ignition timing so that the steady operation state is maintained.

  At time T7 after time T6, knocking determination is OFF. Here, at time T6, the ignition timing command value and the throttle opening command value have returned to the initial values (IN and TPN) of the optimal ignition timing control. However, it takes time from time T6 to time T7 until the once generated knocking vibration is settled. Therefore, the time when knocking determination is OFF is T7.

  After the time T7, that is, after the end of the knocking avoidance control, the optimal ignition timing control executed from the time T2 to the time T5 is executed again. From time T7 to time T8, the ignition timing and throttle opening command values are changed. After time T9, the ignition timing and throttle opening command values are kept substantially constant.

  In the second optimum ignition timing control, the target value of the ignition timing is changed to the retard side. That is, compared with the target value IM in the first optimal ignition timing control, the target value IT2 in the second optimal ignition timing control is larger than the optimal ignition timing IM in the first optimal ignition timing. The retarded side.

  Further, the target value of the throttle opening is also changed with the change of the target value of the ignition timing. Regarding the target value of the throttle opening, the throttle opening of the target value TP2 in the second optimal ignition timing control is larger than the target value TP1 in the second optimal ignition timing control.

  If knocking occurs during the execution of the second optimum ignition timing control, the second optimum ignition timing control is ended, and the second knocking avoidance control is performed. Then, after the second knocking avoidance control, the third optimum ignition timing control is executed.

  In the third optimal ignition timing control, the target value of the ignition timing is further changed to the retard side. In this way, the optimal ignition timing control is repeatedly executed until the ignition timing is such that knocking does not occur even when the optimal ignition timing control is executed for a long time.

  That is, in the second and subsequent optimum ignition timing control, the target value of the ignition timing is set to the retard side by a predetermined correction angle from the target value in the previous optimal ignition timing control.

  However, during the execution of the optimal ignition timing control, for example, when the steady operation state is not maintained due to the operation being performed to accelerate or decelerate, the optimal ignition timing control is performed regardless of whether or not knocking avoidance control is performed. finish. In addition, with the end of the steady operation state, the target value of the ignition timing that has been reduced each time the knocking avoidance control is executed returns to the initial value. The timing at which the lowered target value returns to the initial value may be a timing other than the end of the steady operation state. When the operating state of engine 100 again becomes a steady operating state, optimal ignition timing control is also executed again.

  A procedure for changing the ignition timing and throttle opening command values will be described.

  In the example shown in FIG. 3, the command value of the ignition timing is changed from time T2 to time T3 (first optimal ignition timing control). The ignition timing command value is changed with a substantially constant gradient from time T2 to time T3. Therefore, the elements necessary for changing the ignition timing command value are the value before the change, the value after the change, and the time width required for the change. In the case of the first optimal ignition timing control, IN (value before change), IM (value after change), and a time width from time T2 to time T3 (time width required for change) are: It only has to be specified. The change in the ignition timing command value from time T5 to time T6 (knock avoidance control) is the same.

  The change in the command value for the throttle opening is the same as the change in the command value for the ignition timing. That is, it is only necessary to specify the value before the change, the value after the change, and the time width required for the change. In the case of the first optimal ignition timing control, TP1 (value before change), TPN (value after change), and the time width from time T2 to time T3 (time width required for change) are specified. It should be.

  The values before and after the change in the command value of the throttle opening can be specified based on the values before and after the change in the command value of the ignition timing. As described above, in the optimal ignition timing control and knocking avoidance control, the relationship between the ignition timing and the throttle opening is imposed on the condition that the steady operation state is satisfied. The relationship between the value IN before changing the ignition timing and the value TP1 before changing the throttle opening, and the relationship between the value IM after changing the ignition timing and the value TPN after changing the throttle opening are: Is a relationship that suppresses an increase in output due to a decrease in output due to a change in the throttle opening, and satisfies a steady operation state.

  Based on the ignition timing map data stored in the memory 21, the ECU 20 can specify the target value of the ignition timing according to the throttle opening and the rotational speed. There are two types of ignition timing map data: normal ignition timing (reference ignition timing) and optimum ignition timing that defines an upper limit value at the time of advance by this control. Therefore, the ECU 20 can specify both the value IN before the change and the value IM after the change in the optimal ignition timing control and the knocking avoidance control.

  In the optimal ignition timing control or knocking avoidance control, there are the following two methods for the ECU 20 to specify the throttle opening command value.

  The first method is a method in which map data of the throttle opening is created in the same manner as the ignition timing, and the ECU 20 is referred to the map data of the throttle opening.

  The second method is a method in which the ECU 20 changes the throttle opening command value by feedback control in accordance with the change of the ignition timing command value so that the detected value of the rotational speed does not deviate from a predetermined range. .

  The feedback control performed by the ECU 20 will be described with reference to FIG. In FIG. 3, it appears that the command value of the ignition timing is changed with a substantially constant gradient. Actually, as shown in FIG. 4, the command value is discontinuously changed every minute time dt. That is, the ECU 20 changes the command value step by step. dI represents a one-step displacement amount in the command value of the ignition timing, and dTP represents a one-step displacement amount in the command value of the throttle opening. Here, the ECU 20 tracks the change in the rotational speed every time the ignition timing is changed by one step. In this feedback control, a dead zone centered on the rotation speed is set for the rotation speed. D indicates the dead body width. If the detected value of the rotational speed exceeds the dead zone width D of the rotational speed due to a one-step change (displacement amount dI) of the ignition timing, the ECU 20 determines that the detected rotational speed value is the width of the dead zone width D. The throttle opening command value is changed by one step (displacement amount dTP) so as to be within the range. For example, if the rotation speed increases (output increases) due to the change of the ignition timing and the detected value of the rotation speed exceeds the dead zone width, the throttle opening is decreased by one step in the direction in which the output decreases. A command value is created. If the detected value of the rotational speed does not exceed the dead zone width of the rotational speed due to a one-step change in the ignition timing, the throttle opening is not changed.

  In the example shown in FIG. 3, from time T5 to time T6 (knock avoidance control), the command value of the ignition timing is directed from the optimal ignition timing IM to the normal ignition timing IN (compared to the optimal ignition timing control). It has been changed with a steep slope. As the ignition timing is changed, the command value of the throttle opening is also changed with a steep slope from TP1 to TPN.

  The command value may be changed discontinuously and rapidly by making the gradient for changing the command value of the ignition timing and the throttle opening more steep, that is, perpendicular to the time axis. By doing in this way, the generated knocking can be eliminated more quickly.

  Next, the flow of the main ignition timing control will be described with reference to FIG.

  The ECU 20 starts the main ignition timing control when the engine 100 is started (step S1).

  After step S1, ECU 20 determines whether or not the operating state of engine 100 is in a steady operating state (step S2).

  When the operating state of engine 100 is in the steady operating state, the process of ECU 20 proceeds to step S3. If the operating state of engine 100 is not in the steady operating state, step S2 is repeatedly executed.

  In step S <b> 3, the ECU 20 determines based on the knocking sensor 18 whether knocking vibration has occurred.

  If knocking vibration has occurred, the process of the ECU 20 proceeds to step S4. If knocking vibration has not occurred, the process of the ECU 20 proceeds to step S5.

  In step S4, the ECU 20 executes knocking avoidance control. That is, the ECU 20 sets the normal ignition timing corresponding to the rotation speed as a target value for the ignition timing, and sets the throttle opening corresponding to the normal ignition timing as the target value for the throttle opening. Then, the ECU 20 rapidly brings the command value of the ignition timing close to the target value, and also makes the command value of the throttle opening suddenly approach the target value. Note that the process of step 4 is usually executed after the optimal ignition timing control is executed for a certain period of time, that is, after the process of step S6 is executed a plurality of times and the ignition timing is advanced.

  In step S5, the ECU 20 determines whether or not the current ignition timing command value is on the retard side with respect to the optimal ignition timing. If the ignition timing command value has reached the target optimal ignition timing during execution of the optimal ignition timing control, the ignition timing command value is not retarded from the optimal ignition timing. That is, the ignition timing command value is equal to the optimal ignition timing. On the other hand, when the command value of the ignition timing has not reached the optimum ignition timing which is the target value, the command value of the ignition timing is on the retard side with respect to the optimum ignition timing.

  If the command value of the current ignition timing is on the retard side with respect to the optimal ignition timing, the processing of the ECU 20 proceeds to step S6. If the command value for the current ignition timing is not retarded from the optimal ignition timing, the processing of the ECU 20 returns to step S2.

  In step S6, the ECU 20 executes optimal ignition timing control in one stage. That is, the ECU 20 sets the optimum ignition timing according to the throttle opening and the rotational speed as a target value for the ignition timing, and sets the throttle opening according to the optimum ignition timing as the target value for the throttle opening. Then, the ECU 20 brings the command value of the ignition timing closer to the target value, and brings the command value of the throttle opening closer to the target value. More specifically, in step S6, only one-step control in a plurality of stages until the ignition timing and the throttle opening are changed from the values before the change to the values after change (target values) is executed.

  When the ignition timing control is executed in one step at step S4 or step S6, the process of the ECU 20 is returned to step S2. While the loop from step S2 to step S6 is repeatedly executed, the ignition timing control in the normal operation state is completed, or the ignition timing control in the steady operation state is completed. The reason why the ignition timing control in the normal operation state is not completed in step S4 and the ignition timing control in the steady operation state is not completed in step S6 is as follows. That is, the normal ignition timing control and knocking avoidance control can be interrupted at any time during the execution of the optimal ignition timing control in accordance with the change in the operating state and the occurrence of knocking.

  In the process of step S2, the ECU 20 determines whether or not there is a steady operation state, specifically as follows. The ECU 20 is a steady operation state detection unit. Below, the determination conditions of a steady operation state are shown.

  The first determination condition includes condition (1). Condition (1): The fluctuation range of the rotation speed of the crankshaft 9 is within a predetermined range. Here, the rotational speed of the crankshaft 9 is detected by a rotational speed detection means (crank angle sensor 17 and ECU 20). Further, it is not necessary to detect the rotation speed itself of the crankshaft 9, and it is sufficient that the rotation speed of the rotating body interlocking with the crankshaft 9 can be detected. If the fluctuation range of the rotational speed is within the predetermined range, the fluctuation range of the throttle opening also remains within a certain limited range. For this reason, the minimum condition for the steady operation state can be set based on the fluctuation range of the rotational speed being within the predetermined range.

  The second determination condition further includes a condition (2) in the first determination condition. Condition (2): The fluctuation range of the throttle opening is within a predetermined range. Here, the throttle opening is detected by the throttle sensor 15.

  Further, in the normal operation state, the detected value (command value) of the throttle opening is linked to the operation amount of the throttle grip 30. Therefore, in the second determination condition, the condition (2a) can be applied instead of the condition (2), and the condition (2a) can be applied in addition to the condition (2). Condition (2a): The fluctuation range of the operation amount of the throttle grip 30 is within a predetermined width. The throttle grip 30 is detected by a grip sensor 31.

  The third determination condition further includes a condition (3) in the first or second determination condition. Condition (3): The rotational speed is within a predetermined range and the throttle opening is within a predetermined range. For example, the rotational speed is in the range of 3000 to 12000 rpm, and the throttle opening is in the range of 10% to 60%.

  The fourth determination condition further includes a condition (4) in any one of the first to third determination conditions. Condition (4): The gear ratio is a predetermined gear ratio. Here, the gear ratio is detected by a gear ratio detection sensor 51.

  The fifth determination condition further includes a condition (5) in any one of the first to fourth determination conditions. Condition (5): The water temperature of the radiator is within a specified range. Here, the water temperature of the radiator is detected by a temperature sensor (not shown).

  The sixth determination condition further includes a condition (6) in any one of the first to fifth determination conditions. Condition (6): The brake is in an OFF state. Here, the presence or absence of a brake operation is detected by the brake sensor 41.

  The seventh determination condition further includes a condition (7) in any one of the first to sixth determination conditions. Condition (7): A state in which any one of the first to sixth determination conditions is satisfied continues for a predetermined time (for example, several seconds). Here, the ECU 20 can measure time.

[Effect of the control device according to the present embodiment]
The control device for engine 100 of the present embodiment exhibits the following effects.

  In the steady operation state, the throttle opening is changed in conjunction with the change of the ignition timing, so that the occurrence of output fluctuation is suppressed. For this reason, the operator does not feel discomfort due to the output fluctuation.

  In particular, in the steady operation state, the throttle opening is reduced in conjunction with the change of the ignition timing to the advance side so that the ignition timing is optimally ignited, so that an increase in output is suppressed. For this reason, the operator does not feel discomfort due to the increase in output. In addition, since the ignition timing is controlled to the optimal ignition timing, the fuel consumption of the engine 100 is improved.

  Further, in the steady operation state, the throttle opening is increased in conjunction with the change of the ignition timing to the retard side so that knocking can be avoided, so the occurrence of a decrease in output is suppressed. For this reason, the operator does not feel a sense of incongruity due to a decrease in output. Moreover, occurrence of knocking can be avoided.

  In the optimal ignition timing control after the occurrence of knocking, the target value of the ignition timing is set to the retarded side with respect to the previous optimal ignition timing, so the ignition timing is set to the optimal ignition timing in a state where knocking is unlikely to occur. Can be approached. For this reason, fuel consumption can be improved while preventing knocking.

  Also, since the throttle opening command value is changed by feedback control based on the rotational speed in response to the change in the ignition timing command value, the throttle opening is maintained so as to maintain the steady operation state according to the actual operating conditions. Command value can be changed. Therefore, it is possible to suppress the occurrence of output fluctuations regardless of changes in temperature conditions and fuel conditions. For this reason, the operator does not feel discomfort due to output fluctuation. Further, the fuel consumption of engine 100 can be improved.

  Further, since the steady operation condition satisfies the condition that the fluctuation range of the throttle opening is maintained within the predetermined range, a more stable operation state becomes the steady operation state. For this reason, since output fluctuation suppression control is not performed in the transition period of the operating state, output fluctuation in the steady operating state is further suppressed.

  In addition, since the steady operation condition satisfies the condition that the gear ratio is a predetermined ratio and the condition that the rotation speed is maintained within a predetermined rotation speed range, a more stable operation state is a steady operation state. For this reason, since output fluctuation suppression control is not performed in the transition period of the operating state, output fluctuation in the steady operating state is further suppressed.

  In this embodiment, the normal ignition timing is set with a margin on the retarded side of the torque peak. For this reason, in the optimal ignition timing control, the ECU 20 suppresses an increase in output generated by advancing the ignition timing to the advance side by reducing the throttle opening. As described above, in the present embodiment, the reference torque curve (point sequence data in FIG. 2) used for creating the ignition timing map data, the actual torque curve in the engine 100 to which the output fluctuation suppression control is applied, Are assumed to be the same. However, depending on various conditions such as environmental conditions in which engine 100 is used, the phase of the reference torque curve differs from the actual torque curve. For example, the normal ignition timing that was on the retarded side of the torque peak in the reference torque curve may move to the advanced side of the torque peak in the actual torque curve. As an example of countermeasures against such a situation, only the optimal ignition timing is adjusted. Specifically, the optimal ignition timing is set to the retard side of the normal ignition timing so that the optimal ignition timing approaches the actual torque peak. Here, it does not matter whether the optimum ignition timing is the retard side or the advance side of the actual torque peak. At this time, the ECU 20 advances the ignition timing to the retard side in the optimal ignition timing control. The increase in output generated by advancing toward the retard side is suppressed by reducing the throttle opening. That is, in the output fluctuation suppression control (optimum ignition timing control), the direction in which the ignition timing is changed may be either the advance side or the retard side.

  The present invention is not limited to the above embodiment. Various modifications and changes can be made without departing from the spirit and scope of the invention as set forth in the appended claims.

  It can be applied to an engine control device equipped with an electronically controlled throttle.

It is a block diagram which shows an engine and the control apparatus of an engine. It is a figure which shows an example of the point sequence data which show the relationship between ignition timing and a torque in a predetermined throttle opening and a predetermined rotation speed. It is a figure which shows the time chart of ignition timing control. It is a figure which shows the time chart from the time T2 of FIG. 3 to the time T3. It is a flowchart of ignition timing control.

Explanation of symbols

15 Throttle sensor (throttle opening detection means)
17 Crank angle sensor (part of rotation speed detection means)
18 Knocking sensor (knocking detection means)
20 EPU (command value creation means, steady operation state detection means)
21 Memory (storage means)
100 engine

Claims (7)

Throttle opening detection means for detecting the throttle opening of the engine;
A rotational speed detection means for detecting the rotational speed of the engine;
Command value creating means for creating a command value of the ignition timing of the engine and the throttle opening;
Storage means for storing a target ignition timing set according to the throttle opening and the rotational speed;
Steady operation state detection means for detecting whether or not the engine operation state is in a steady operation state;
With
The steady operation state satisfies a condition that the fluctuation range of the rotation speed is maintained within a predetermined range,
The command value creating means executes output fluctuation suppression control when the steady operation state is detected,
The output fluctuation suppression control is a command value of the ignition timing, with the target ignition timing corresponding to the throttle opening and the rotation speed detected when the steady operation state is started as the target value of the ignition timing. The throttle opening command value is changed so that the steady output state is maintained by suppressing the engine output fluctuation due to the ignition timing change.
Engine control device. The control device further comprises storage means for storing a normal ignition timing set according to the throttle opening and the rotational speed,
The normal ignition timing is an ignition timing that is set as a target value of the ignition timing when the operating state is not at least the steady operating state,
The target ignition timing is an optimal ignition timing that is on the more advanced side than the normal ignition timing,
The output fluctuation suppression control is optimal ignition timing control,
The optimal ignition timing control is a command value for the ignition timing with the optimal ignition timing corresponding to the throttle opening and the rotation speed detected when the steady operation state is started as the target value of the ignition timing. The throttle opening command value is reduced so that the steady operation state is maintained by suppressing an increase in output due to the change of the ignition timing.
The engine control apparatus according to claim 1. The control device further comprises:
Knocking detection means for detecting knocking of the engine;
Storage means for storing a reference ignition timing that is retarded from the optimal ignition timing and is set according to the throttle opening and the rotational speed;
With
The target ignition timing is the optimal ignition timing and the reference ignition timing;
The output fluctuation suppression control is optimal ignition timing control and knocking avoidance control,
When the knocking is detected during the execution of the optimum ignition timing control, the command value creating means ends the optimum ignition timing control and performs the knocking avoidance control.
In the knocking avoidance control, the ignition timing command value is set with the reference ignition timing corresponding to the throttle opening and the rotation speed detected when the steady operation state is started as the target value of the ignition timing. It is a control to increase the command value of the throttle opening so as to be close to the target value and suppress the output decrease due to the change of the ignition timing and maintain the steady operation state.
The engine control device according to claim 2. The command value creating means performs the optimum ignition timing control again when the steady operation state is detected after the knocking avoidance control is completed,
The command value creating means sets the target value of the ignition timing in the second and subsequent optimal ignition timing controls to a retard side by a predetermined correction angle from the target value in the previous optimal ignition timing control. ,
The engine control device according to claim 3. In the optimal ignition timing control or the knocking avoidance control, the command value creating means is configured to perform the ignition so that the rotational speed does not deviate from the predetermined range including the rotational speed when the steady operation state is started. According to the change of the command value of the timing, the command value of the throttle opening is changed by feedback control.
The engine control device according to any one of claims 2 to 4. The steady operation state further satisfies the condition that the fluctuation range of the throttle opening is kept within a predetermined range,
The engine control apparatus according to any one of claims 1 to 5. The control device further includes a gear ratio detecting means for detecting a gear ratio in a transmission for shifting the output of the engine.
The steady operation state further satisfies a condition that the gear ratio is a predetermined ratio and a condition that the rotational speed is maintained within a predetermined rotational speed range.
The engine control device according to any one of claims 1 to 6.

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