JP2018173002A - Control device for vehicular engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a vehicular engine, capable of detecting abnormal idle of the engine.SOLUTION: The control device for the vehicular engine includes an intake passage 11, a throttle valve 13, a bypass passage 15 bypassing the throttle valve 13, an idle speed control valve 14 provided in the bypass passage 15, a speed sensor 32, a throttle sensor 33, fuel cut means 31, control means 31 for controlling the opening of the idle speed control valve 14 to keep an engine speed during idling to be a preset target speed, and abnormality determination means 31 for determining that abnormal idle occurs in the engine 1 during idling when the throttle opening is a predetermined first opening threshold value or smaller and the frequency of fuel cut is a predetermined frequency threshold value or greater within a predetermined time.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control device for a vehicle engine, and more particularly to a control device that detects and copes with an idle abnormality of an engine mounted on a motorcycle.

  Patent Document 1 discloses an intake passage connected to an engine, a throttle valve provided in the intake passage, a bypass passage connected to the intake passage and bypassing the throttle valve, and an idle speed control valve (hereinafter referred to as an idle speed control valve) provided in the bypass passage. , Sometimes referred to as ISCV). Even if the throttle opening of the throttle valve is maintained in a fully closed or slightly opened state during engine idling, the amount of intake air to the engine is adjusted by controlling the opening of the ISCV, and the engine speed is set to a predetermined value. Maintained at the value.

JP 2011-80480 A

  However, if the dirt adhering to the ISCV hardens and the ISCV sticks while the valve is open, that is, so-called open sticking, the ISCV may become uncontrollable while the engine is idling. When the ISCV becomes uncontrollable and the amount of intake air into the engine increases, the engine speed increases to an unintended speed, and engine idle control cannot be performed appropriately.

  In addition, as described in Patent Document 1, when the target opening of the ISCV is determined based on learning, the opening of the ISCV cannot be appropriately controlled due to erroneous learning caused by the driving situation of the vehicle. An engine idle abnormality may occur. For this reason, it has been conventionally required to detect engine idle abnormality.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a vehicle engine control device that can detect engine idle abnormality.

  In order to achieve the above object, a control apparatus for a vehicle engine according to the present invention includes an intake passage connected to the engine, a throttle valve provided in the intake passage, a bypass passage connected to the intake passage and bypassing the throttle valve. An idle speed control valve provided in the bypass passage, a rotational speed sensor for detecting the engine rotational speed, a throttle sensor for detecting the throttle opening of the throttle valve, and the engine rotational speed at a predetermined upper limit during idling of the engine A fuel cut means for cutting off fuel supply to the engine, an engine speed detected by a speed sensor, and a throttle opening detected by a throttle sensor. And the engine by controlling the opening of the idle speed control valve based on Control means for maintaining the engine speed during idling at a preset target speed, and fuel cut performed by the fuel cut means when the throttle opening is equal to or less than a predetermined first opening threshold during engine idling And an abnormality determining means for determining that an idle abnormality has occurred when the number of times exceeds a predetermined number of times threshold within a predetermined time.

  On the other hand, another control device for a vehicle engine according to the present invention includes an intake passage connected to the engine, a throttle valve provided in the intake passage, a bypass passage connected to the intake passage and bypassing the throttle valve, and a bypass passage An idle speed control valve, an engine speed sensor for detecting the engine speed, a throttle sensor for detecting the throttle opening of the throttle valve, an engine speed detected by the engine speed sensor, and a throttle sensor detected by the throttle sensor The control means for adjusting the opening of the idle speed control valve based on the opening and maintaining the engine speed at a preset target speed during engine idling, and the engine speed during engine idling , Larger than a predetermined first rotation speed threshold, and then the target rotation speed is set to a predetermined If the engine speed is equal to or greater than the value obtained by adding the two rotation speed thresholds and the engine speed is less than the predetermined third rotation speed threshold for a predetermined time after activation of the control means, and these conditions continue for a predetermined time, And an abnormality determining means for determining that the occurrence has occurred.

  Preferably, after it is determined by the abnormality determination means that an idle abnormality has occurred, the control means sets the drive duty ratio of the idle speed control valve to zero, and the engine speed adds a predetermined fourth speed threshold value to the target speed. When the state in which the drive duty ratio is larger than the value and the drive duty ratio is zero continues for a predetermined time, it further includes an abnormality determining means that determines that the idle speed control valve is fixed while the idle speed control valve remains open as an idle abnormality. .

  Preferably, after it is determined by the abnormality determination means that an idle abnormality has occurred, the control means sets the drive duty ratio of the idle speed control valve to zero, and the engine speed adds a predetermined fourth speed threshold value to the target speed. And an abnormality determining means for determining that the idle abnormality is an open fixation that is fixed while the idle speed control valve is open when a state in which the drive duty ratio is zero and the drive duty ratio is zero is continued. The fuel cut means cuts off the fuel supply to the engine when it is determined by the abnormality determining means that the open fixing of the idle speed control valve has occurred.

  Preferably, the control means determines a correction value for correcting the opening degree of the idle speed control valve during idling of the engine by learning, and the abnormality confirmation means has a predetermined fifth rotation speed threshold value at which the engine speed is set to a target speed. When a state that is equal to or less than the value obtained by adding is continued for a predetermined time, it is determined that an erroneous learning of the correction value learned by the control means has occurred as an idle abnormality.

  Preferably, after it is determined by the abnormality determination means that an idle abnormality has occurred, the control means sets the drive duty ratio of the idle speed control valve to zero, and the engine speed adds a predetermined fifth speed threshold value to the target speed. When the state that is equal to or less than the predetermined value continues for a predetermined time, an abnormality determining unit that further determines that an erroneous learning of the correction value learned by the control unit has occurred as an idle abnormality.

  Preferably, the control means changes the correction value so as to reduce the drive duty ratio of the idle speed control valve when it is determined that the erroneous learning of the correction value has occurred by the abnormality determination means.

  According to the vehicle engine control apparatus of the present invention, it is possible to detect engine idle abnormality.

1 is a system configuration diagram illustrating a control device for a vehicle engine according to an embodiment of the present invention. It is a flowchart which shows the temporary determination A which ECU of FIG. 1 performs. It is a flowchart which shows the temporary determination B which ECU of FIG. 1 performs. It is a flowchart which shows the determination determination X which ECU of FIG. 1 performs. It is a flowchart which shows the determination determination Y which ECU of FIG. 1 performs.

A vehicle engine control apparatus according to an embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram showing a control device of the engine 1. The vehicle is, for example, a motorcycle, and the engine 1 is, for example, a 4-cycle single-cylinder gasoline engine with a displacement of 50 cc, and is a driving power source for the motorcycle. The specifications of the engine 1 are not limited to those shown in FIG. 1 and can be arbitrarily changed. Further, illustrations and descriptions of components that are obvious to be provided in the motorcycle are omitted as appropriate.

  A flywheel 7 is attached to the rear end (transmission side not shown) of the crankshaft 6 that rotates when the engine 1 operates. At a predetermined position on the outer periphery of the flywheel 7, a reluctor 7a for detecting the crank angle is formed.

  The engine 1 is formed with an intake port 9a and an exhaust port 9b. An intake passage 11 is connected to the intake port 9a. The intake passage 11 is provided with a throttle valve 13 and an injector 16 in order from the upstream side in the intake air flow direction.

  The throttle valve 13 is opened and closed according to the driver's throttle operation. The injector 16 injects fuel toward the intake port 9a. A bypass passage 15 that bypasses the throttle valve 13 is connected to the intake passage 11, and an ISCV (idle speed control valve) 14 is provided in the bypass passage 15. On the other hand, an exhaust passage 17 is connected to the exhaust port 9b.

  The ISCV 14 is a so-called duty solenoid valve (Duty Sole Noid Valve) whose opening is adjusted by a drive duty ratio (ratio of ON time to total time of ON time and OFF time). Here, the ON time is a time during which the ISCV 14 is opened, and the OFF time is a time during which the ISCV 14 is closed. Even if the throttle opening θth of the throttle valve 13 is maintained in a fully closed or slightly opened state while the engine 1 is idling, the ISCV 14 adjusts the intake air amount to the engine 1 by controlling the opening of the ISCV 14, and the engine rotation The number Ne is maintained at a preset target rotational speed Net.

  The opening of the ISCV 14 is adjusted by feedback control of the drive duty ratio of the ISCV 14 so that the engine speed Ne during idling becomes the target speed Net. For this feedback control, a correction value is used that takes into account the effects of machine differences in the engine 1, aging deterioration, etc., and the traveling environment of the vehicle. This correction value is a value for correcting the drive duty ratio of the ISCV14. The correction value is updated as needed by learning so that the opening of the ISCV 14 matches the target opening.

  More specifically, when the engine speed Ne during idling is higher than the first threshold th1, the correction value is updated so as to make the drive duty ratio of the ISCV 14 smaller. On the other hand, when the engine speed Ne during idling is lower than the second threshold th2, the correction value is updated so as to increase the drive duty ratio of the ISCV 14. Here, the first threshold th1 and the second threshold th2 are set in advance so that “first threshold th1> target rotational speed Net> second threshold th2” is satisfied.

  A fuel pump 26 supplies fuel such as gasoline stored in the fuel tank 25 to the injector 16. The fuel pump 26 can pressurize and supply fuel. The fuel pump 26 and the injector 16 are integrally formed, and are connected to the fuel tank 25 via a supply hose 27 and a return hose 28, respectively.

  When the fuel pump 26 operates, the fuel in the fuel tank 25 is guided into the fuel pump 26 via the supply hose 27 and pressurized to a predetermined pressure, and the pressurized fuel is supplied to the injector 16. Since the surplus fuel in the injector 16 is collected in the fuel tank 25 via the return hose 28, fuel of a predetermined pressure is always supplied to the injector 16. As a result, when the injector 16 is opened, fuel of a predetermined injection timing and injection amount is injected toward the intake port 9a.

  During operation of the engine 1, outside air is sucked into the intake passage 11 during the intake stroke. The intake air sucked into the intake passage 11 is adjusted in flow rate according to the throttle opening θth of the throttle valve 13 and then flows into the cylinder of the engine 1 while being mixed with the fuel injected from the injector 16. The air-fuel mixture that has undergone compression in the subsequent compression stroke is ignited, burned during the expansion stroke, and imparts rotational force to the crankshaft 6. In the subsequent exhaust stroke, the exhaust gas after combustion is discharged from the cylinder of the engine 1 and discharged to the outside through the exhaust passage 17.

  The combustion cycle of the engine 1 described above is executed based on the control of the ECU 31 (engine control unit). The ECU 31 has a processor (not shown), and functions as control means, fuel cut means, abnormality determination means, and abnormality confirmation means by executing a program that realizes various procedures described later by the processor. Various sensors such as an electromagnetic pickup (rotational speed sensor) 32 and a throttle sensor 33 are connected to the input side of the ECU 31, and switches such as a neutral SW (neutral switch) 37 and a clutch SW (clutch switch) 38 are also provided. It is connected.

  The electromagnetic pickup 32 is disposed to face the flywheel 7 and outputs a crank angle signal synchronized with the proximity of the reluctator 7 a accompanying the rotation of the flywheel 7. The throttle sensor 33 detects the throttle opening θth of the throttle valve 13.

  The neutral SW 37 is turned on when the gear position of a transmission (not shown) of the vehicle is in the neutral position. The clutch SW 38 is turned on when a clutch (not shown) disconnects the engine 1 and the transmission. Various devices such as the throttle valve 13, ISCV 14, injector 16, and fuel pump 26 are connected to the output side of the ECU 31.

  The ECU 31 controls the fuel injection control for driving the injector 16 based on the sensor information described above, the ignition timing control for igniting the air-fuel mixture, the pump control for driving the fuel pump 26, and the ISCV 14 during idling of the engine 1. The engine 1 is operated by executing various controls such as idle control for opening control, idle abnormality detection control for detecting idle abnormality based on open fixation of the ISCV 14 and false learning.

  In the fuel injection control executed by the ECU 31, the target fuel injection amount is determined based on the engine speed Ne calculated from the signal of the electromagnetic pickup 32, the throttle opening θth detected by the throttle sensor 33, and the like. The injector 16 is driven at a predetermined timing in the intake stroke to execute fuel injection.

  In the ignition timing control executed by the ECU 31, the target ignition timing is determined based on the engine speed Ne, the throttle opening θth, and the like. The ECU 31 shapes the signal of the electromagnetic pickup 32 to generate a rectangular wave-shaped crank angle signal synchronized with the reluctator 7a (in other words, the crank angle). Then, the target ignition timing is determined based on this crank angle signal.

  In the pump control executed by the ECU 31, in the normal mode that is one of the operation modes of the vehicle, the fuel pump 26 is driven during operation of the engine 1 to supply the fuel pressurized to a predetermined pressure to the injector 16. On the other hand, in the pump control, when shifting to the fuel cut mode which is one of the operation modes of the vehicle, the fuel pump 26 is stopped when the predetermined condition is satisfied, thereby stopping the fuel supply to the injector 16.

The ECU 31 functions as a fuel cut means, and executes mode switching control between a normal mode and a fuel cut mode described below.
Assuming that the initial mode is the normal mode, switching from the normal mode to the fuel cut mode is performed only when all of the following conditions (1) to (3) are satisfied.

(1) The elapsed time t1 after the start of the engine 1 or the elapsed time t1 after returning from the previous fuel cut mode to the normal mode is equal to or longer than the predetermined time t1s. (2) The engine speed Ne is a predetermined first time. (3) The throttle opening θth is smaller than the predetermined throttle lower limit opening θthl.

Such a vehicle state corresponds to a state where a fuel cut is necessary, for example, when the vehicle is traveling downhill with inertia.
Further, when the vehicle is operating in the fuel cut mode, the fuel cut mode is switched to the normal mode when either of the following conditions (1) and (2) is satisfied.

(1) The engine speed Ne is equal to or lower than the second upper limit speed Neu2. (2) The throttle opening .theta.th is equal to or greater than a predetermined throttle lower limit opening .theta.thl. Is appropriately performed. Appropriate values are appropriately set for the predetermined time t1s, the first upper limit rotation speed Neu1, the second upper limit rotation speed Neu2, and the throttle lower limit opening θthl. For example, the first upper limit rotation speed Neu1 and the second upper limit rotation speed Neu2 are determined in advance such that “first upper limit rotation speed Neu1> second upper limit rotation speed Neu2” is established. However, the present invention is not limited to this, and the same upper limit rotational speed Neu may be set as the first upper limit rotational speed Neu1 and the second upper limit rotational speed Neu2.

  On the other hand, the ECU 31 functions as a control unit, and as the above-described idle control, based on the engine speed Ne detected based on the signal of the electromagnetic pickup 32 and the throttle opening θth detected by the throttle sensor 33, The drive duty ratio of the ISCV 14 is updated. As a result, the opening degree of the ISCV 14 is controlled, and even if the throttle opening degree θth of the throttle valve 13 is maintained in the fully closed state or the slightly opened state while the engine 1 is idling, the opening degree control of the ISCV 14 is applied to the engine 1. The intake air amount is adjusted, and the engine speed Ne is maintained at a preset target speed Net.

However, when the dirt adhering to the ISCV 14 is hardened and the ISCV 14 is stuck open, the ISCV 14 becomes uncontrollable while the engine 1 is idling, and the amount of intake air into the engine 1 increases, causing the engine speed Ne to rotate unintentionally. In this case, the idle control of the engine 1 cannot be appropriately performed.
Further, as described above, since the correction value of the drive duty ratio of the ISCV 14 is determined based on learning, the opening degree of the ISCV 14 cannot be appropriately controlled due to erroneous learning due to the driving situation of the vehicle, etc. In some cases, an engine 1 idle abnormality may occur.

  Therefore, in the present embodiment, the ECU 31 detects the idle abnormality of the engine 1 by executing the idle abnormality detection control described above, accurately identifies the cause, and reliably suppresses the increase in the engine speed Ne during idling. doing. The ECU 31 functions as an abnormality determination means, and first makes provisional determinations A and B, and tentatively determines that the ISCV 14 is open-fixed based on these results.

  Then, the ECU 31 functions as an abnormality determination means, so that only when the conditions of the provisional determinations A and B are satisfied, the determination of the fixed determination X of the ISCV open fixation and the determination determination Y of the ISCV mislearning is performed. Do. That is, in the idle abnormality detection control of the present embodiment, an accurate cause of the idle abnormality of the engine 1 is performed by performing the two-stage abnormality detection determination based on the two provisional determinations A and B and the two final determinations X and Y. Identification and coping are possible.

Hereinafter, the procedure of provisional determination A executed by the ECU 31 will be described with reference to the flowchart of FIG.
When the procedure of the provisional determination A is started, first, in step S11, it is determined whether or not the throttle opening θth is equal to or less than a predetermined first opening threshold θths1. When the determination result is Yes, the process proceeds to step S12. On the other hand, when the determination result is No, the process remains in step S11 and continues to perform the same determination.

  In step S12, it is determined whether or not the neutral SW 37 is ON, or whether or not the clutch SW 38 is ON, that is, whether or not the engine 1 is idling. When the determination result is Yes, the process proceeds to step S13, and when the determination result is No, the process returns to step S11 and the determination is performed again.

  In step S13, it is determined whether or not the number of times of transition to the fuel cut mode, that is, the fuel cut number Nfc is equal to or greater than a predetermined number threshold Nfcs within a predetermined time. When the determination result is Yes, the process proceeds to step S14. On the other hand, when the determination result is No, the process returns to step S11 and the determination is performed again.

In step S14, it is determined that the condition of provisional determination A is satisfied, and this procedure is terminated. Appropriate values are appropriately set for the first opening threshold value θths1 and the frequency threshold value Nfcs.
Thus, in the temporary determination A, it is temporarily determined that the ISCV 14 is open-fixed only when all of the determination results in steps S11 to S13 are Yes. The condition of the provisional determination A is satisfied because the engine 1 is idling and the engine speed Ne continues to increase despite the throttle opening θth being throttled, and fuel cuts occur frequently. This is when the vehicle is suspected of being stuck open in ISCV14.

Hereinafter, the procedure of provisional determination B executed by the ECU 31 will be described with reference to the flowchart of FIG.
When the procedure of provisional determination B is started, first, in step S21, it is determined whether or not the engine speed Ne is greater than a predetermined first speed threshold value Nes1. When the determination result is Yes, the process proceeds to step S22. On the other hand, when the determination result is No, the process stays at step S21 and continues to perform the same determination.

  In step S22, it is determined whether or not the engine rotational speed Ne is equal to or greater than a value obtained by adding a predetermined second rotational speed threshold Nes2 to a target rotational speed Net preset by the ECU 31. When the determination result is Yes, the process proceeds to step S23. On the other hand, when the determination result is No, the process returns to step S21 to perform the determination again.

  In step S23, it is determined whether a crank angle signal has been input, in other words, whether a signal from the electromagnetic pickup 32 has been detected. When the determination result is Yes, the process proceeds to step S24, and when the determination result is No, the process waits until a crank signal is input in step S23.

  In step S24, it is determined whether or not the throttle opening degree θth is equal to or smaller than a predetermined second opening degree threshold value θth2. That is, it is determined whether or not the throttle opening θth never becomes larger than the second opening threshold θth2 after the crank angle signal is input, in other words, whether or not the vehicle is stopped. When the determination result is Yes, the process proceeds to step S25. On the other hand, when the determination result is No, the process returns to step S21 to perform the determination again.

  In step S25, it is determined whether or not the neutral SW 37 is ON, or whether or not the clutch SW 38 is ON, that is, whether or not the engine 1 is idling. When the determination result is Yes, the process proceeds to step S26, and when the determination result is No, the process returns to step S21 to perform the determination again.

  In step S26, after the ECU 31 is started, that is, after the key is turned on, it is determined whether or not the engine speed Ne is smaller than a predetermined third speed threshold value Nes3. When the determination result is Yes, the process proceeds to step S27. When the determination result is No, the process returns to step S21 to perform the determination again.

  In step S27, it is determined whether or not the determination result in step S26 is Yes after the ECU 31 is started, that is, the elapsed time t2 after the key is turned on is within the predetermined time t2s. When the determination result is Yes, the process proceeds to step S28. On the other hand, when the determination result is No, the process returns to step S21 to perform the determination again.

  In step S28, it is determined whether or not the continuation time t3 in which all the Yes results of the determination results in steps S21 to S27 are equal to or longer than a predetermined time t3s. When the determination result is Yes, the process proceeds to step S29. On the other hand, when the determination result is No, the process proceeds to step S21, and it is determined whether or not all Yes establishments of the determination results of steps S21 to S27 are continuously maintained for a predetermined time t3s or more.

  In step S29, it is determined that the condition of provisional determination B is satisfied, and this procedure is terminated. The first rotation speed threshold Nes1, the target rotation speed Net, the second rotation speed threshold Nes2, the second opening threshold value θths2, the third rotation speed threshold Nes3, the predetermined time t2s, and the predetermined time t3s are appropriately set appropriately. Is set. For example, the first rotation speed threshold value Nes1, the second rotation speed threshold value Nes2, and the third rotation speed threshold value Nes3 satisfy “second rotation speed threshold value Nes2> first rotation speed threshold value Nes1> third rotation speed threshold value Nes3”. Predetermined. For example, the first opening threshold value θths1 and the second opening threshold value θths2 are determined in advance so that “first opening threshold value θths1 = second opening threshold value θths2” is established.

  As described above, in the provisional determination B, it is temporarily determined that the ISCV 14 is open-fixed only when all of the determination results in steps S21 to S28 are Yes. The condition of provisional determination B is satisfied because the engine 1 is idling and the engine speed Ne continues to increase although the fuel is not cut even though the throttle opening θth is throttled. Etc., when the vehicle is in a state of being suspected of being stuck open to the ISCV14.

Hereinafter, with reference to the flowchart of FIG. 4, the procedure of the determination determination X executed by the ECU 31 will be described.
Prior to the start of the determination determination X procedure, as a premise determination, first, in step S31, it is determined whether or not at least one of the above-described provisional determinations A and B is satisfied. When the determination result is Yes, the process proceeds to step S32. On the other hand, when the determination result is No, the process remains in step S31 and continues to perform the same determination.

In step S32, the drive duty ratio of the ISCV 14 is forcibly set to zero, and the process proceeds to step S33.
In step S33, it is determined whether or not the engine rotational speed Ne is larger than a value obtained by adding a predetermined fourth rotational speed threshold Nes4 to a target rotational speed Net preset by the ECU 31. When the determination result is Yes, the process proceeds to step S34, and when the determination result is No, the process returns to step S31 and the determination is performed again.

In step S34, it is determined whether or not the drive duty ratio of the ISCV 14 is zero. When the determination result is Yes, the process proceeds to step S35. On the other hand, when the determination result is No, the process returns to step S33 to perform the determination again.
In step S35, it is determined whether or not the throttle opening θth is equal to or smaller than a predetermined third opening threshold θths3. When the determination result is Yes, the process proceeds to step S36. On the other hand, when the determination result is No, the process returns to step S33 to perform the determination again.

  In step S36, it is determined whether or not the continuation time t4 in which all of the determination results in steps S33 to S35 are satisfied is equal to or longer than a predetermined time t4s. When the determination result is Yes, the process proceeds to step S37. On the other hand, when the determination result is No, the process proceeds to step S33, and it is determined in step S36 whether or not all Yes determination results in steps S33 to S35 are continuously maintained for a predetermined time t4s or longer.

In step S37, it is determined that the condition for determination determination X is satisfied, and the process proceeds to step S38.
In step S38, the vehicle is shifted to the fuel cut mode, and this procedure is terminated. Appropriate values are set as appropriate for the target rotation speed Net, the fourth rotation speed threshold value Nes4, the third opening degree threshold value θths3, and the predetermined time t4s. For example, the fourth rotation speed threshold Nes4 is determined in advance so that “second rotation speed threshold Nes2 = second rotation speed threshold Nes2” is established. For example, the third opening threshold value θths3 is determined in advance so that “third opening threshold value θths3 = second opening threshold value θths2” is established.

As described above, in the determination determination X, only when all the determination results in steps S33 to S36 are Yes, it is determined that the ISCV 14 is open-fixed, and then the fuel cut is performed to cause the ISCV 14 to be open-fixed. The increased engine speed Ne is reliably suppressed.
The condition of the final determination X is satisfied in addition to the condition of the provisional determination A or B, and after the drive duty ratio of the ISCV 14 is forcibly set to zero, the drive duty ratio remains zero, but the engine This is when the vehicle is in a state where the open fixing of the ISCV 14 can be determined, such as when the rotational speed Ne continues to rise.

Hereinafter, with reference to the flowchart of FIG. 5, the procedure of the determination determination Y which ECU31 performs is demonstrated.
Prior to the start of the determination determination Y, as in the case of the determination determination X, as a premise determination, first, in step S41, it is determined whether or not at least one of the provisional determinations A and B described above has been established. When the determination result is Yes, the process proceeds to step S42. On the other hand, when the determination result is No, the process remains in step S41 and continues to perform the same determination.

In step S42, the drive duty ratio of the ISCV 14 is forcibly set to zero, and the process proceeds to step S43.
In step S43, it is determined whether or not the engine rotational speed Ne is equal to or less than a value obtained by adding a predetermined fifth rotational speed threshold Nes5 to a target rotational speed Net preset by the ECU 31. When the determination result is Yes, the process proceeds to step S44. On the other hand, when the determination result is No, the process returns to step S43 to perform the determination again.

  In step S44, it is determined whether or not the continuation time t5 for establishing Yes in the determination result in step S43 is equal to or longer than a predetermined time t5s. When the determination result is Yes, the process proceeds to step S45. On the other hand, when the determination result is No, the process proceeds to step S43, and it is determined whether the establishment of Yes in the determination result of step S43 is continuously maintained for a predetermined time t5s or longer.

In step S45, it is determined that the condition for determination determination Y is satisfied, and the process proceeds to step S46.
In step S46, the correction value is updated so as to reduce the drive duty ratio of the ISCV 14, and this procedure is terminated. Appropriate values are appropriately set for the target rotation speed Net, the fifth rotation speed threshold value Nes5, and the predetermined time t5s. For example, the fifth rotation speed threshold value Nes5 is determined in advance so that “fifth rotation speed threshold value Nes5 = fourth rotation speed threshold value Nes4” is established.

  Thus, in the determination determination Y, only when all the determination results in steps S43 and S44 are Yes, it is determined that the ISCV 14 mislearning has occurred, and then the drive duty ratio of the ISCV 14 is decreased. By updating the correction value, the increase in the engine speed Ne caused by the erroneous learning of the ISCV 14 is reliably suppressed.

  In addition to the provisional determination A or B condition, the condition of the determination determination Y is satisfied, and after the drive duty ratio of the ISCV14 is forcibly set to zero, the drive duty ratio becomes higher due to a correction value based on erroneous learning of the ISCV14. Thus, the engine speed Ne is slightly increased, but is not in a state where the engine speed Ne is not continuously increasing, such as in a vehicle state where erroneous learning of the ISCV 14 can be determined.

  As described above, in the present embodiment, when the condition of the provisional determination A is satisfied, the engine speed Ne continues to increase despite the engine 1 being idle and the throttle opening θth being throttled. Thus, it is possible to detect a vehicle state in which the ISCV 14 is suspected of being stuck open, such as frequent fuel cuts.

  On the other hand, when the condition of the provisional determination B is satisfied, the engine 1 is idle, the vehicle is stopped, and the engine is not able to cut the fuel even though the throttle opening θth is throttled. It is possible to detect a vehicle state in which ISCV 14 is suspected of being openly stuck, for example, when the rotational speed Ne continues to increase.

  Furthermore, when the condition of the final determination X is satisfied, in addition to the condition of the provisional determination A or B, after forcibly setting the drive duty ratio of the ISCV 14 to zero, the drive duty ratio remains zero, It is possible to detect a vehicle state in which the open fixing of the ISCV 14 can be determined, such as when the engine speed Ne continues to increase.

  On the other hand, when the condition of the final determination Y is satisfied, in addition to the condition of the provisional determination A or B, the driving duty ratio of the ISCV 14 is forcibly set to zero, and then the driving duty ratio is determined by a correction value based on erroneous learning of the ISCV 14. Although the engine speed Ne is slightly increased and the engine speed Ne is slightly increased, it is not in a state where the engine speed Ne is not continuously increased. Therefore, it is possible to detect a vehicle state in which it is not determined that the ISCV 14 is stuck open but is erroneously learned by the ISCV 14.

  By performing these provisional judgments A and B and final judgments X and Y, the engine 1 idle abnormality is detected, and whether the cause is the open stuck state of the ISCV 14 or the erroneous learning of the ISCV 14 is accurately identified. can do. Further, when the ISCV 14 is stuck open, fuel cut is performed. On the other hand, when the ISCV 14 is mislearned, the correction value is updated so as to reduce the drive duty ratio of the ISCV 14 to thereby reduce the engine speed Ne during idling. It is possible to reliably suppress an unintentional rise.

This is the end of the description of the embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention.
For example, in the idle abnormality detection control of the above-described embodiment, both the provisional determinations A and B are determined, and then, when at least one condition of the provisional determinations A and B is satisfied, both the determination determinations X and Y are determined. It is carried out. In this idle abnormality detection control, by performing two-stage abnormality detection determination based on the two provisional determinations A and B and the two final determinations X and Y, it is possible to accurately identify and deal with the cause of the engine 1 idle abnormality. It is said.

  However, the present invention is not limited to this, and after determining only one of the provisional determinations A and B, determination of both or only the determination determinations X and Y may be performed. Further, the determinations X and Y may not be performed, and the open fixing of the ISCV 14 may be determined and determined based on the result of only one or both of the provisional determinations A and B being established. Even in these cases, the cause of the idle abnormality of the engine 1 can be identified and dealt with with a predetermined accuracy.

1 Engine 11 Air intake passage 13 Throttle valve 14 ISCV (idle speed control valve)
15 Bypass passage 31 ECU (fuel cut means, control means, abnormality determination means, abnormality determination means)
32 Electromagnetic pickup (rotational speed sensor)
33 Throttle sensor

Claims (7)

An intake passage connected to the engine;
A throttle valve provided in the intake passage;
A bypass passage connected to the intake passage and bypassing the throttle valve;
An idle speed control valve provided in the bypass passage;
A rotational speed sensor for detecting the engine rotational speed;
A throttle sensor for detecting a throttle opening of the throttle valve;
Fuel cut means for cutting fuel supply to the engine when the engine speed is greater than a predetermined upper limit speed and the opening is smaller than a predetermined lower limit during idling of the engine;
The engine during idling of the engine is controlled by controlling the opening of the idle speed control valve based on the engine speed detected by the speed sensor and the throttle opening detected by the throttle sensor. Control means for maintaining the rotational speed at a preset target rotational speed;
When the throttle opening is equal to or less than a predetermined first opening threshold and the number of fuel cuts performed by the fuel cut means is equal to or greater than a predetermined number of thresholds within a predetermined time during idling of the engine, A vehicle engine control device comprising: an abnormality determination unit that determines that an abnormality has occurred. An intake passage connected to the engine;
A throttle valve provided in the intake passage;
A bypass passage connected to the intake passage and bypassing the throttle valve;
An idle speed control valve provided in the bypass passage;
A rotational speed sensor for detecting the engine rotational speed;
A throttle sensor for detecting a throttle opening of the throttle valve;
Based on the engine speed detected by the speed sensor and the throttle opening detected by the throttle sensor, the opening of the idle speed control valve is adjusted, and the engine speed during idling of the engine Control means for maintaining the target rotational speed set in advance,
During idling of the engine, the engine speed becomes greater than a predetermined first rotational speed threshold, and then becomes equal to or greater than a value obtained by adding a predetermined second rotational speed threshold to the target rotational speed, and the control means An abnormality determining means for determining that an idle abnormality has occurred when the engine rotational speed is less than a predetermined third rotational speed threshold value within a predetermined time after the activation of the engine, and when these states continue for a predetermined time. Engine control device. After the abnormality determining means determines that the idle abnormality has occurred, the control means sets the drive duty ratio of the idle speed control valve to zero,
When the engine speed is larger than a value obtained by adding a predetermined fourth speed threshold value to the target speed and the drive duty ratio is zero for a predetermined time, the idle speed control is performed as the idle abnormality. The vehicle engine control device according to claim 1, further comprising abnormality determining means for determining that an open sticking that has stuck while the valve is open has occurred. After the abnormality determining means determines that the idle abnormality has occurred, the control means sets the drive duty ratio of the idle speed control valve to zero,
When the engine speed is larger than a value obtained by adding a predetermined fourth speed threshold value to the target speed and the drive duty ratio is zero for a predetermined time, the idle speed control is performed as the idle abnormality. It further comprises an abnormality determining means for determining that an open sticking has occurred while the valve is open,
2. The vehicle engine control device according to claim 1, wherein the fuel cut unit cuts off the fuel supply to the engine when it is determined by the abnormality determination unit that the idle speed control valve is stuck open. 3. The control means determines by learning a correction value for correcting the opening of the idle speed control valve during idling of the engine,
The abnormality determining means is learned by the control means as the idle abnormality when a state where the engine speed is equal to or less than a value obtained by adding a predetermined fifth engine speed threshold value to the target engine speed continues for a predetermined time. The vehicle engine control device according to claim 3, wherein it is determined that an erroneous learning of the correction value has occurred. After the abnormality determining means determines that the idle abnormality has occurred, the control means sets the drive duty ratio of the idle speed control valve to zero,
When the state where the engine speed is equal to or less than a value obtained by adding a predetermined fifth rotation speed threshold value to the target speed continues for a predetermined time, an error in the correction value learned by the control means is detected as the idle abnormality. The vehicle engine control device according to claim 1, further comprising abnormality determination means for determining that learning has occurred.   The control means changes the correction value so as to reduce the drive duty ratio of the idle speed control valve when it is determined that the correction value is erroneously learned by the abnormality determination means. The vehicle engine control device according to claim 1.

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