JP4412177B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine that controls an actual opening, which is a detected value of an actual opening of a throttle valve opened and closed by an actuator, to a target opening.

  This type of control device generally calculates the target opening of the throttle valve based on the operation amount of the engine in addition to the operation amount of the accelerator pedal. Then, feedback control is performed so that the detected value of the actual opening (actual opening) becomes the calculated target opening. Further, in the above control device, when it is detected that an abnormality has occurred in the electronic throttle system, usually, when the throttle valve is electrically opened and closed, the throttle valve is mechanically fixed at a predetermined opening. Then, fail-safe control for performing evacuation traveling is executed.

  However, if the opening degree of the throttle valve is fixed at a predetermined opening degree at the time of the abnormality, the intake air amount of the internal combustion engine is abruptly reduced, so that the output and the rotational speed of the internal combustion engine may change abruptly. Therefore, conventionally, as seen in Patent Document 1, for example, when the throttle valve is fixed at a predetermined opening, a purge valve for leading the vaporized fuel gas from the fuel tank to the intake passage of the internal combustion engine may be opened. Proposed. As a result, the change in the intake air amount after being fixed with respect to the intake air amount before the throttle valve is fixed at the predetermined opening is suppressed, and consequently, the engine before and after the throttle valve is fixed at the predetermined opening. Output fluctuation can be suppressed.

  By the way, in the said control apparatus, the following inconveniences may arise before the said fail safe control is performed. That is, for example, when an abnormality occurs in a sensor that detects the actual opening of the throttle valve and the detected opening decreases rapidly, normal feedback control is performed while determining that the abnormality is abnormal. Is called. However, since there is a large difference between the target opening and the detected opening at this time, the actual opening is controlled to the fully open side by feedback control. As a result, the output of the engine may be unintentionally controlled to the increase side.

  It should be noted that the actual throttle valve opening is not limited to feedback control to the target opening, but the throttle valve actual opening is controlled to the target opening when the electronic throttle system is abnormal. Such a situation in which the output of the engine may be unintentionally increased is also common.

Incidentally, as the control device, there is, for example, Patent Document 2 in addition to Patent Document 1.
Japanese Patent Laid-Open No. 2001-50094 JP-A-10-153142

  The problem to be solved by the present invention is that the output of the engine is controlled to increase when an abnormality occurs in the electronic throttle system. An object of the present invention is to provide a control device for an internal combustion engine that can suitably suppress an unintended increase in the output of the engine even when an abnormality occurs in the electronic throttle system. .

  In the following, means for achieving these objects and their effects are described.

  According to the first aspect, in the control device for an internal combustion engine that feedback-controls the actual opening degree of the throttle valve that is opened and closed by the actuator to the target opening degree, the decrease rate of the actual opening degree with respect to the target opening degree is not less than a predetermined value. In this case, among the operation objects for controlling the output of the engine, the operation objects other than the throttle valve are forcibly operated to the side for suppressing the output of the engine.

  When an abnormality occurs in the electronic throttle system that feeds back the throttle valve, there is a possibility that the actual opening degree with respect to the target opening degree is rapidly reduced. In this case, the output of the engine may increase unintentionally before fail-safe control such as mechanically controlling the opening of the throttle valve to a preset opening is performed.

  In this regard, in the above configuration, in such a situation, an operation for suppressing the output of the engine is forcibly performed, and thus it is possible to suitably suppress a large increase in the output of the engine.

  Incidentally, here, “suppression” includes control (prevention) in which increase in output is “0” and control in which output is decreased. Here, the “opening degree” is the maximum when the throttle valve is fully open and the minimum (“0”) when the throttle valve is fully closed. Further, the reduction rate takes a larger value as the degree of reduction is larger. In other words, when the actual opening relative to the target opening does not change, the decrease rate is “0”, and when it increases, the decrease rate is negative. Furthermore, the decrease rate of the actual opening relative to the target opening is defined by defining the change rate of the actual opening relative to the target opening as positive on the decrease side. For this reason, even when the actual opening is constant and the target opening rapidly increases, the decrease rate of the actual opening with respect to the target opening rapidly increases.

  It is desirable that the forcible operation be performed for a predetermined period longer than the time required for diagnosing the presence or absence of an abnormality in the electronic throttle system, or for a period until the abnormality diagnosis is completed.

  In means 2, it is determined in means 1 that the decreasing speed of the actual opening with respect to the target opening is equal to or greater than a predetermined value based on the decreasing speed of the actual opening.

  For example, when an abnormality occurs in the means for detecting the opening of the throttle valve, the detected opening (actual opening) may decrease rapidly. In this case, the actual opening with respect to the target opening may decrease rapidly.

  In this regard, in the above configuration, it is possible to appropriately determine that the rate of decrease of the actual opening with respect to the target opening is equal to or greater than a predetermined value.

  At this time, when the rate of decrease of the actual opening becomes equal to or greater than a predetermined value, it may be determined that the rate of decrease of the actual opening with respect to the target opening becomes equal to or greater than a predetermined value.

  In the means 3, in the means 2, the target is set based on at least one of the condition that the target opening is not more than a predetermined value and the condition that the operation amount of the accelerator operating member does not correspond to a rapid deceleration request. It was determined that the decrease rate of the actual opening with respect to the opening became a predetermined value or more.

  When the target opening degree decrease rate is large, the actual opening degree decreasing rate with respect to the target opening degree may not increase even if the actual opening decrease rate is large.

  In this regard, in the above configuration, based on the fact that the target opening degree reduction rate is less than or equal to a predetermined value, it is determined that the actual opening degree reduction rate with respect to the target opening value has become a predetermined value or more. Judgment can be made more appropriately.

  In addition, when the operation amount of the accelerator operation member does not correspond to a sudden deceleration request (when the operation amount is steady or corresponds to an acceleration request, etc.), the actual opening may suddenly decrease. I don't get it. For this reason, under such circumstances, when the rate of decrease of the actual opening is large, the rate of decrease of the actual opening with respect to the target opening becomes large, and it is considered that the output of the engine is unintentionally increased. .

  In this regard, in the above-described configuration, based on the fact that the operation amount of the accelerator operation member does not correspond to a rapid deceleration request, it is determined that the actual opening reduction rate with respect to the target opening has become a predetermined value or more. Thus, this judgment can be made more appropriately.

  In the means 1, as in the means 4, the means for calculating the target opening based on the operation amount of the accelerator operating member, and the change rate of the difference between the target opening and the actual opening are calculated. Means for calculating, and based on the calculated change speed, it may be determined whether or not the rate of decrease of the actual opening relative to the target opening is greater than or equal to a predetermined value.

  Note that the difference is “target opening degree−actual opening degree”, and the rate of change may be defined by the difference in time-series data for each unit time.

  In the means 5, in any one of the means 1 to 4, the forcible operation is performed when the actual opening is smaller than the target opening in addition to the determination that the predetermined opening or more is reached. I did it.

  Even when the actual opening with respect to the target opening rapidly decreases, the output of the engine is not greatly increased when the actual opening rapidly decreases from a value larger than the target opening.

  In this regard, in the above configuration, it is possible to avoid performing the forcible operation when the actual opening degree suddenly decreases from a value larger than the target opening degree.

  The forcible operation may be performed when the actual opening is smaller than a target opening by a predetermined amount or more. That is, when the target opening is smaller than the actual opening but the difference is small, it is considered that the output of the engine will not be increased unintentionally. You may do it.

  The means 6 includes a calculating means for calculating the target opening degree based on the operation amount of the accelerator operating member in the means 1, and when the increase rate of the target opening degree is not less than a predetermined value, It was determined that the rate of decrease of the actual opening with respect to the opening to be performed was greater than or equal to a predetermined value.

  When the target opening degree is calculated based on the operation amount of the accelerator operation member, there is an upper limit to the change rate of the operation amount of the accelerator operation member. For this reason, there is also an upper limit to the target opening rate of change. Therefore, if the target change rate of the opening degree exceeds this upper limit, some abnormality may occur. In particular, when the target opening degree increases rapidly, the decrease rate of the actual opening degree with respect to the target opening degree increases rapidly, and the output of the engine is unintentionally controlled to increase. There is.

  In this regard, in the above-described configuration, it is possible to appropriately determine that the rate of decrease in the actual opening with respect to the target opening is greater than or equal to a predetermined value due to an abnormality occurring in the electronic throttle system.

  In the control device for an internal combustion engine that controls the actual opening, which is a detected value of the actual opening of the throttle valve that is opened and closed by the actuator, to the target opening, the target 7 is based on the operation amount of the accelerator operation member. Calculating means for calculating the opening degree, and when an increase rate of the target opening degree is not less than a predetermined value, an operation object other than the throttle valve is selected among the operation objects for controlling the output of the engine. Forcibly operated to suppress the output of the engine.

  When the target opening degree is calculated based on the operation amount of the accelerator operation member, there is an upper limit to the change rate of the operation amount of the accelerator operation member. For this reason, there is also an upper limit to the target opening rate of change. Therefore, if the target change rate of the opening degree exceeds this upper limit, some abnormality may occur. In particular, when the target opening degree increases rapidly, the output of the engine may be unintentionally increased.

  In this regard, in the above configuration, it is possible to suitably suppress unintentional increase control of the output of the engine.

  Incidentally, here, “suppression” includes control (prevention) in which increase in output is “0” and control in which output is decreased. Here, the “opening degree” is the maximum when the throttle valve is fully open and the minimum (“0”) when the throttle valve is fully closed.

  It is desirable that the forcible operation be performed for a predetermined period longer than the time required for diagnosing the presence or absence of an abnormality in the electronic throttle system, or for a period until the abnormality diagnosis is completed.

  In the means 8, in the means 6 or 7, the calculating means calculates means for calculating an opening degree of the throttle valve required in auto-cruise control for controlling the speed of the vehicle on which the engine is mounted, and the vehicle. Means for calculating the opening degree of the throttle valve required for traction control to suppress slippage of the drive wheel, and the throttle required for controlling the engine speed at idling to a target speed At least one of the means for calculating the opening of the valve, and the target increase rate of the opening used in the determination excludes a change in the opening calculated by the at least one means. I was supposed to be.

  The auto cruise control, the traction control, and the rotational speed control during idling are performed independently of the operation amount of the accelerator operation member, in other words, independent of the command from the user. And when these controls act on the side which increases the target opening, the increase rate of the target opening may become more than predetermined by these contributions.

  In this regard, in the above configuration, since the change in the target opening degree due to the auto cruise control, traction control, and rotational speed control during idling is removed, the output of the engine is appropriately controlled when the electronic throttle system is abnormal. Suppressing control can be performed.

  In any one of the means 1 to 8, as in the means 9, the forcible operation may include an operation to retard the ignition timing.

  As for the means 9, as in the means 10, the operation toward the retard side may be the most retarded angle operation.

  Here, the most retarded angle operation refers to an operation to a maximum retard angle timing (retard angle guard value) determined when manipulating the ignition timing. This maximum retard timing (retard guard value) may be variably set according to the operating state of the engine. In this case, the most retarded angle operation is either (a) an operation to the maximum retard timing set according to the operating state of the engine, or (b) the maximum retard timing in any operating state. The operation is to the value on the most retarded side.

  In any one of the means 1 to 10, as with the means 11, the forcible operation may include an operation for reducing the fuel injection amount to the engine.

  In the means 12, the reducing operation in the means 11 may be an operation for stopping the fuel injection.

  When the exhaust system of the internal combustion engine is provided with a catalyst for purifying exhaust gas, the air-fuel ratio is normally controlled to a predetermined value in order to maintain the purification capacity of the catalyst. That is, the fuel injection amount is set to a value for maintaining good exhaust characteristics. For this reason, if the fuel injection amount is reduced below the set value (but not “0”), the exhaust characteristics deteriorate.

  In this regard, in the above configuration, it is possible to avoid the deterioration of the exhaust characteristics by stopping the fuel injection.

  Hereinafter, a first embodiment of a control device for an internal combustion engine according to the present invention will be described with reference to the drawings.

  FIG. 1 shows the control device and its drive target. A throttle valve 4 that adjusts the flow passage area of the intake passage 2 is provided on the upstream side of the intake passage 2 of the internal combustion engine 1. The throttle valve 4 is of an electronic control type and is driven to open and close by a motor 6. A fuel injection valve 8 that injects and supplies fuel is provided downstream of the intake passage 2. The intake passage 2 is connected to the combustion chamber 10, and a mixture of fuel and air injected from the fuel injection valve 8 is supplied to the combustion chamber 10. On the other hand, a spark plug 12 is provided in the combustion chamber 10 so as to protrude therefrom, and the air-fuel mixture supplied to the combustion chamber 10 is used for combustion by ignition of the spark plug 12.

  The electronic control unit 20 includes a microcomputer that incorporates a central processing unit, a memory, and the like. The electronic control device 20 takes in the detection values of various sensors that detect the operating state and operating environment of the internal combustion engine 1, user requests, and the like. Specifically, a detection value (actual opening TH) of the throttle sensor 30 that detects the opening degree of the throttle valve 4, a detection value (depression amount AP) of the accelerator sensor 34 that detects the depression amount of the accelerator pedal 32, and the like. It is captured.

  The electronic control device 20 performs various calculations and controls based on the detection values of the various sensors. This control largely controls the output of the internal combustion engine 1 (the output torque of the crankshaft 38 as the engine output shaft). That is, the electronic control unit 20 operates the throttle valve 4, the fuel injection valve 8, the spark plug 12, and the like in order to control the output of the internal combustion engine 1.

  Further, the electronic control unit 20 sets the actual opening TH to the target opening (target opening TA) of the throttle valve 4 calculated each time based on the depression amount AP in order to appropriately operate the throttle valve 4. Feedback control to follow is performed. This will be described below.

  FIG. 2 shows a processing procedure for performing feedback control of the actual opening TH of the throttle valve 4 to the target opening TA. This process is repeatedly executed by the electronic control unit 20 at a predetermined cycle, for example.

  In this series of processing, first, in step S10, the depression amount AP of the accelerator pedal 32 is captured. In step S12, the target opening degree TA is calculated based on the depression amount AP. Here, the target opening degree TA may be calculated in consideration of the detection value of an appropriate sensor for detecting the operating state and operating environment of the internal combustion engine 1. In calculating the target opening degree TA, it is desirable to perform a process for suppressing a sudden change in the target opening degree TA. As this processing, for example, a target opening TA [i] calculated this time and a target opening TA [i-1] calculated last time are added with standardized weights to obtain a final target. There is a so-called annealing process that is a weighted average process for setting the opening degree TA. Incidentally, in this case, the weight b (a + b = 1) given to the target opening TA [i−1] calculated last time is larger than the weight a given to the target opening TA [i] calculated this time. It is desirable to set.

  In step S14, the actual opening TH is taken in. In step S16, PID control (P: proportional control, I: integral control, D: differential control) is performed based on the target opening degree TA and the actual opening degree TH.

  In the above aspect, the actual opening TH is appropriately controlled to the target opening TA. Further, in the present embodiment, there is a diagnostic function for diagnosing an abnormality of the electronic throttle system that includes the throttle valve 4, the throttle sensor 30, the accelerator pedal 32, and the accelerator sensor 34. When an abnormality is diagnosed, fail-sail control is performed such that the throttle valve 4 is mechanically fixed at a predetermined opening and retreating is performed.

  However, when an abnormality occurs in the electronic throttle system, the following inconvenience may occur due to the feedback control before the fail-safe control is performed.

  That is, for example, when the throttle sensor 30 is short-circuited with the ground (GND), the actual opening TH that is taken in as a detection value of the throttle sensor 30 may be fully closed (opening “0”). In this case, the actual opening TH with respect to the target opening TA rapidly decreases, and the feedback control amount for controlling the opening of the throttle valve 4 becomes a large value. That is, the throttle valve 4 is controlled to the fully open side. As a result, the output of the internal combustion engine 1 may be unintentionally increased.

  On the other hand, the abnormality diagnosis requires a certain amount of time in order to maintain high accuracy. That is, when the detected value of the throttle sensor 30 is suddenly changed temporarily due to noise or the like, a process for not diagnosing this as an abnormality is performed for the abnormality diagnosis. For this reason, the situation where the output of the internal combustion engine 1 is unintentionally increased as described above occurs between the time when the abnormality diagnosis is completed and the fail safe is executed.

  Therefore, in this embodiment, in order to avoid such unintended increase control of the output of the internal combustion engine 1, the output of the internal combustion engine 1 is suppressed when the rate of decrease of the actual opening TH with respect to the target opening TA is equal to or greater than a predetermined value. Control to do. FIG. 3 shows the procedure of the output control process. This process is repeatedly executed by the electronic control unit 20 at a predetermined cycle, for example.

  In this series of processes, first, in step S20, it is determined whether the depression amount AP of the accelerator pedal 32 is steady or increasing. Here, “increase” means that when the accelerator pedal AP is depressed and a request for acceleration is generated from the user, in other words, a request for increasing the opening of the throttle valve 4 is generated from the user. Specifically, it is determined whether or not a value obtained by subtracting the stepping amount AP [i−1] fetched last time from the stepping amount AP [i] fetched this time is equal to or larger than a predetermined value α. Here, the predetermined value α is a value for determining whether or not the depression amount AP is in a steady state or increasing. If the stepping amount AP is increasing, “AP [i] −AP [i−1]” is positive. Further, if the depression amount AP is in a steady state, “AP [i] −AP [i−1]” is substantially “0”. For this reason, in the present embodiment, the predetermined value α is set to a small negative value.

  If it is determined in step S20 that it is steady or increasing, it is determined in step S22 whether the target opening degree TA is substantially constant or increasing. Specifically, it is determined whether or not a value obtained by subtracting the previously calculated target opening degree TA [i-1] from the currently calculated target opening degree TA [i] is equal to or larger than a predetermined value β. Here, the predetermined value β is a value for determining whether or not the target opening degree TA is substantially constant or increasing. If the target opening degree TA is increasing, “TA [i] −TA [i−1]” is positive. If the target opening degree TA is substantially constant, “TA [i] −TA [i−1]” is substantially “0”. For this reason, in the present embodiment, the predetermined value β is set to a small negative value.

  If it is determined in step S22 that the target opening degree TA is substantially constant or increasing, it is determined in the subsequent step S24 whether the target opening degree TA is larger than the actual opening degree TH. Here, the target opening degree TA [i] calculated this time is compared with the actual opening degree TH [i] acquired this time.

  If it is determined in step S24 that the target opening degree TA is greater than the actual opening degree TH, in the subsequent step S26, it is determined whether or not the rate of decrease in the actual opening degree TH is greater than or equal to a predetermined value. Specifically, it is determined whether or not a value obtained by subtracting the actual opening TH [i-1] previously acquired from the actual opening TH [i] acquired this time is equal to or less than a predetermined value γ. Here, the predetermined value γ is a value for determining whether or not the decrease rate of the actual opening TH is equal to or higher than a predetermined value.

  If it is determined in step S26 that the rate of decrease in the actual opening TH is greater than or equal to a predetermined value, in step S28, the fuel cut operation or the ignition timing retard operation is forcibly performed for a predetermined period. That is, control for suppressing the output of the internal combustion engine 1 is performed.

  Here, when the process proceeds to step S28, there is no user's request for deceleration (step S20). Further, there is no situation in which the target opening degree TA decreases rapidly (step S22). Under such circumstances, the actual opening TH cannot be decreased rapidly. Therefore, if it is determined in step S26 that the decrease rate of the actual opening TH is greater than or equal to a predetermined value, there is a high possibility that an abnormality has occurred in the electronic throttle system. However, a certain amount of time is required until an abnormality is diagnosed by the process for diagnosing whether or not an abnormality has occurred in the electronic throttle system.

  Moreover, since the actual opening TH is smaller than the target opening TA (step S24), it is considered that the actual opening TH is considerably smaller than the target opening TA. That is, as shown in FIG. 4, the actual opening TH follows the target opening TA, but suddenly (at time t1) there is a situation in which the actual opening TH suddenly decreases. Conceivable. Therefore, it is considered that control is performed such that the opening degree of the throttle valve 4 is increased by the feedback control shown in FIG.

  In such a situation, the fuel cut operation or the ignition timing retard operation is forcibly performed for a predetermined period, thereby suppressing the output of the internal combustion engine 1 from being unintentionally increased. Here, the forced operation means that the above operation is performed ignoring the request for the fuel injection amount and the ignition timing set according to the operating state of the internal combustion engine 1 and the like. Therefore, even during this forced operation, the fuel injection amount and the ignition timing are calculated each time according to the operating state of the internal combustion engine 1 and the like.

  It is desirable that the retard operation of the ignition timing is an operation to the maximum retard timing (retard guard value) determined when the ignition timing is manipulated. This maximum retard timing (retard guard value) may be variably set according to the operating state of the internal combustion engine 1. In this case, (a) the operation to the maximum retard timing set according to the operating state of the internal combustion engine 1, or (b) the most retarded side of the maximum retard timing in any operating state. An operation on a value.

  This forcible operation is performed over a predetermined period T. The predetermined period T is set based on the time required for completing the abnormality diagnosis when an abnormality occurs in the electronic throttle system. That is, for example, the predetermined period T is set to a period (for example, 2 to 4 cycles of the internal combustion engine 1; 1 cycle = 4 strokes) until the completion of the abnormality diagnosis and the fail safe control is started. As a result, as shown in FIG. 4 above, when the actual opening TH decreases rapidly at time t1, a forced injection operation of fuel injection or a forced retarding operation of ignition timing is performed for a predetermined period T.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) When the rate of decrease of the actual opening TH is greater than or equal to the predetermined opening degree TA, an operation for forcibly cutting fuel injection or an operation for forcibly retarding the ignition timing is performed. Thereby, it can suppress suitably that the output of the internal combustion engine 1 increases largely unintentionally.

  (2) Based on the decreasing speed of the actual opening TH, it was determined that the decreasing speed of the actual opening TH with respect to the target opening TA became equal to or higher than a predetermined value. Thereby, it can be appropriately determined that the decrease rate of the actual opening TH with respect to the target opening TA has become a predetermined value or more.

  (3) The above operation is performed based on the target opening degree TA being substantially constant or increasing. Thereby, since the decrease rate of the target opening degree TA is large, the forcible operation can be performed while appropriately eliminating the case where the decrease rate of the actual opening degree TH becomes large.

  (4) The above operation is performed based on whether the accelerator pedal depression amount AP is in a steady state or increasing. Thus, the forcible operation can be performed while appropriately eliminating the case where the decrease rate of the actual opening TH increases due to the deceleration request from the user.

  (5) The forcible operation is performed based on the condition that the actual opening TH is smaller than the target opening TA. As a result, the forcible operation can be performed while appropriately excluding the time when the actual opening TH suddenly decreases from a value larger than the target opening TA.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, the rate of change of the difference between the target opening degree TA and the actual opening degree TH is calculated, and when this is equal to or greater than a predetermined value, control for suppressing the output of the internal combustion engine 1 is performed.

  FIG. 5 shows a processing procedure of output control in the present embodiment. This process is repeatedly executed in the electronic control device 20 at a predetermined cycle, for example.

  In this series of processing, first, in step S30, the change rate of the difference between the target opening degree TA and the actual opening degree TH is calculated. Specifically, from the difference “TA [i] −TH [i]” between the target opening TA [i] calculated this time and the actual opening TH [i] acquired this time, the target opening calculated last time is calculated. The speed of change is calculated by subtracting the difference “TA [i−1] −TH [i−1]” between the degree TA [i−1] and the actual opening degree TH [i−1] previously captured.

  In a succeeding step S32, it is determined whether or not the change amount of the difference “TA−TH” is larger than a predetermined value ε. The predetermined value ε is used to determine that a change that cannot occur at normal time has occurred, such as the change in the actual opening TH shown in FIG. In particular, when the increasing speed is large rather than the difference decreasing speed, the actual opening TH is smaller than the target opening TA, and the throttle valve 4 is controlled to the fully open side by the feedback control shown in FIG. The situation is determined.

  If it is determined in step S32 that the increase rate of the difference “TA−TH” is equal to or greater than a predetermined value, the fuel cut operation or the ignition timing retarding operation is forcibly performed over a predetermined period T in step S34. Thus, an unintended increase in the output of the internal combustion engine 1 is suppressed.

  When it is determined in step S32 that the increase rate of the difference “TA−TH” is not equal to or greater than a predetermined value, or when the process of step S34 is completed, the series of processes is temporarily terminated.

  Also according to the present embodiment described above, the effect (1) of the first embodiment can be obtained.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, control is performed to suppress the output of the internal combustion engine 1 when the increase rate of the target opening degree TA is equal to or greater than a predetermined value.

  FIG. 6 shows the procedure of the output control process. This process is repeatedly executed by the electronic control unit 20 at a predetermined cycle, for example.

  In this series of processes, first, in step S40, the changing speed of the target opening degree TA is calculated. Specifically, the difference “TA [i] −TA [i−1]” between the target opening degree TA [i] calculated this time and the target opening degree TA [i−1] calculated last time is changed as described above. Calculate as speed. In the subsequent step S42, it is determined whether or not the change speed is equal to or greater than a predetermined value ω. Here, the predetermined value ω is a value for determining a rapid increase in the target speed that cannot be caused by the operation of the accelerator pedal 32 by the user. When it is determined in step S42 that the change speed is equal to or greater than the predetermined value ω, the intention of the output of the internal combustion engine 1 is obtained by forcibly performing the fuel cut operation or the retard operation of the ignition timing in step S44. The control which suppresses increase is performed.

  When it is determined in step S42 that the amount of change is less than the predetermined value ω, or when the process of step S44 is completed, this series of processes is temporarily terminated.

  By performing such processing, for example, as illustrated in FIG. 7, feedback control is performed to approximate the actual opening TH to the target opening TA by rapidly increasing the target opening TA at time t <b> 11. Even so, the output of the internal combustion engine 1 can be prevented from increasing unintentionally.

  Also according to the present embodiment described above, the effect (1) of the first embodiment can be obtained.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the third embodiment.

  In the present embodiment, the target opening degree TA shown in FIG. 2 is calculated in the manner shown in FIG. FIG. 8 is a functional block for calculating the target opening degree TA according to the present embodiment.

  The accelerator request amount calculation unit B2 is a part that calculates a control amount of the opening degree of the throttle valve 4 according to the depression amount of the accelerator pedal 32, in other words, according to a request from the user.

  The auto-cruise required amount calculation unit B4 is a part that calculates a control amount of the opening degree of the throttle valve 4 required for auto-cruise control for controlling the speed of the vehicle on which the internal combustion engine 1 is mounted in a predetermined manner.

  The traction request amount calculation unit B6 is a part that calculates a control amount of the opening degree of the throttle valve 4 that is required for traction control that suppresses slipping of drive wheels of the vehicle on which the internal combustion engine 1 is mounted.

  The ISC request amount calculation unit B8 is a part that calculates a control amount of the opening degree of the throttle valve 4 required when controlling the rotation speed of the internal combustion engine 1 at idling to a target rotation speed.

  And, the actual target opening degree TA is larger of (a) the control amount calculated by the accelerator request amount calculation unit B2 and (b) the control amount calculated by the auto cruise request amount calculation unit B4, or (C) The control amount calculated by the traction request amount calculation unit B6 is calculated by adding (d) the ISC request amount calculation unit B8 or the control amount. However, actually, the control amount of the opening degree of the throttle valve 4 based on the detection values of various sensors that detect the operating state and operating environment of the internal combustion engine 1 is further added. In addition, it is desirable to add an appropriate process for suppressing the sudden change in the target opening degree TA, for example, after adding the opening degree control amount calculated by the ISC required amount calculation unit B8.

  In such a configuration, the target opening degree TA may increase depending on the control amount of the opening degree of the throttle valve 4 for auto-cruise control, traction control, and idle rotation control. And when the target opening degree TA becomes large due to these control amounts, it is not necessarily appropriate to perform control to suppress the output of the internal combustion engine 1. On the other hand, when performing calculations that reflect these control amounts in the final target opening degree TA, the target opening degree TA may suddenly increase due to an error in the calculation.

  Accordingly, in the present embodiment, control is performed to suppress the output of the internal combustion engine 1 when the target opening degree TA becomes large due to such calculation errors, abnormality of the accelerator sensor 34, and the like. When the target opening degree TA becomes large, the following processing is performed so as not to perform the control for suppressing the output.

  FIG. 9 shows the procedure of the output control process in this embodiment. This process is repeatedly executed by the electronic control unit 20 at a predetermined cycle, for example.

  In this process, when the control amount calculated by the auto-cruise request amount calculation unit B4 is larger than the control amount calculated by the accelerator request amount calculation unit B2 (step S50, yes), the target opening degree TA is automatically set. Since the cruise control amount is added, the control amount is subtracted from the target opening degree TA (step S52).

  When traction control is being performed (step S54, yes), the traction control amount is subtracted from the target opening degree TA (step S56). Further, when the idle rotation control is being performed (step S58, yes), this control amount is further subtracted (step S60). Thus, after removing the auto cruise control amount, the traction control amount, and the idle rotation control amount from the target opening degree TA calculated by the processing shown in FIG. 8, the change speed is calculated, and the change speed is It is determined whether or not the predetermined value ω shown in FIG. 6 is exceeded (step S62). When the change speed is equal to or higher than the predetermined value ω, the fuel cut operation or the ignition timing retard operation is forcibly performed (step S64).

  According to the present embodiment described above, the following effects can be obtained in addition to the effects of the fourth embodiment.

  (6) The forcible operation is performed based on the change speed of the target opening degree TA from which the change due to the rotational speed control at the time of idling and auto cruise control, traction control, and the idling is removed. As a result, it is possible to avoid performing control to suppress the output of the internal combustion engine 1 when these changes increase the target opening degree TA and the change speed becomes equal to or greater than the predetermined value ω.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  In the first embodiment, the fuel cut operation or the retard operation of the ignition timing is performed on the condition that the depression amount AP of the accelerator pedal 32 is steady or increasing. A small case may be included in the above conditions.

  In the first embodiment, the fuel cut operation or the ignition timing retarding operation is performed on the condition that the target opening degree TA is steady or increasing, but the target opening degree TA decreases slowly. May be included in the above conditions.

  In the first embodiment, the fuel cut operation or the ignition timing retarding operation is performed on the condition that the actual opening TH is smaller than the target opening TA, but the actual opening is smaller than the target opening TA. The condition may be that TH is smaller than a predetermined value. In other words, when the target opening degree TA is smaller than the actual opening degree TH but the difference is small, it is considered that the output of the internal combustion engine 1 is not unintentionally increased greatly. You may make it do.

  In the second embodiment, the condition for performing the fuel cut operation or the ignition timing retard operation may include that the actual opening TH is smaller than the target opening TA. Further, the actual opening TH may be smaller than the target opening TA by a predetermined amount or more.

  In the third embodiment, a condition that the rate of increase of the actual opening TH is equal to or less than a predetermined value may be included as a condition for performing the fuel cut operation or the retard operation of the ignition timing.

  The method for reflecting the auto cruise control, the traction control, and the idle rotation speed control in the target opening degree TA is not limited to that illustrated in FIG.

  ・ When the actual opening reduction rate with respect to the target opening is greater than or equal to a predetermined value, out of the operation objects for controlling the output of the engine, set the operation object other than the throttle valve to the side that suppresses the output of the engine. The method for forcibly operating is not limited to the fuel cut operation or the ignition timing retard operation. For example, both the fuel cut operation and the ignition timing retard operation may be performed. Further, the forcible operation is not limited to a predetermined period, and the operation may be terminated based on, for example, completion of abnormality diagnosis of the electronic throttle system (as a trigger).

  -As an electronic throttle system, it is not restricted to what was illustrated by the said embodiment. For example, the process of calculating the target opening degree TA and the process of feedback controlling the actual opening degree TH to the target opening degree TA may be performed in different cycles. Further, the accelerator operation member operated by the user so that the user can request acceleration or deceleration is not limited to the accelerator pedal 32 operated by the user. Further, the method of performing feedback control to the actual opening as the target opening is not limited to PID control. Furthermore, not only those that perform feedback control, but even those that perform open loop control, there is a risk that the output of the engine will be unintentionally increased if the target opening increases rapidly. Therefore, the application of the present invention is effective.

  In addition, the configuration of the internal combustion engine 1 is not limited to that illustrated in the above embodiments. For example, instead of the intake port injection type, a cylinder injection type may be used.

The figure which shows 1st Embodiment of the control apparatus of the internal combustion engine concerning this invention, and the structure of the drive object. The flowchart which shows the process sequence of the feedback control of the throttle valve concerning the embodiment. The flowchart which shows the process sequence of the suppression control of the output of the internal combustion engine concerning the embodiment. The time chart which shows the control aspect of the suppression control of the said output. The flowchart which shows the process sequence of the suppression control of the output of the internal combustion engine concerning 2nd Embodiment. The flowchart which shows the process sequence of the suppression control of the output of the internal combustion engine concerning 3rd Embodiment. The time chart which shows the control aspect of the suppression control of the said output. The functional block diagram which shows the calculation aspect of the target opening degree of the throttle valve concerning 4th Embodiment. The flowchart which shows the process sequence of the suppression control of the output of the internal combustion engine concerning the embodiment.

Explanation of symbols

  TH: actual opening, TA: target opening, AP: depression amount, 1 ... internal combustion engine, 4 ... throttle valve, 8 ... fuel injection valve, 12 ... spark plug, 20 ... electronic control device, 32 ... accelerator pedal.

Claims (10)

In a control device for an internal combustion engine that feedback-controls an actual opening that is a detected value of an actual opening of a throttle valve that is opened and closed by an actuator to a target opening,
Among the operation objects for controlling the output of the engine when the actual opening is smaller than the target opening and the rate of decrease of the actual opening with respect to the target opening is not less than a predetermined value. A control apparatus for an internal combustion engine, wherein an operation object other than the throttle valve is forcibly operated so as to suppress the output of the engine. The control apparatus for an internal combustion engine according to claim 1,
A control apparatus for an internal combustion engine, characterized in that, based on the decrease rate of the actual opening, it is determined that the decrease rate of the actual opening with respect to the target opening is equal to or greater than a predetermined value. Based on at least one of a condition that the target opening reduction rate is not more than a predetermined value and a condition that the operation amount of the accelerator operating member does not correspond to a rapid deceleration request, the actual opening degree with respect to the target opening degree is determined. 3. The control device for an internal combustion engine according to claim 2, wherein it is determined that the rate of decrease in the opening degree is equal to or greater than a predetermined value. The control apparatus for an internal combustion engine according to claim 1,
Means for calculating the target opening based on the amount of operation of the accelerator operating member; and means for calculating the rate of change of the difference between the target opening and the actual opening;
A control apparatus for an internal combustion engine, wherein, based on the calculated change speed, it is determined whether or not a decrease speed of the actual opening relative to the target opening is equal to or greater than a predetermined value. The control apparatus for an internal combustion engine according to claim 1,
A calculating means for calculating the target opening based on an operation amount of an accelerator operating member;
The control apparatus for an internal combustion engine , wherein when the increase rate of the target opening is equal to or greater than a predetermined value, it is determined that the decrease rate of the actual opening with respect to the target opening is equal to or greater than a predetermined value . The calculation means includes means for calculating an opening degree of the throttle valve required in auto-cruise control for controlling the speed of a vehicle on which the engine is mounted, and traction control for suppressing slip of drive wheels of the vehicle. Means for calculating the opening degree of the throttle valve required at the time, and means for calculating the opening degree of the throttle valve required when controlling the rotational speed of the engine at idling to a target rotational speed. With at least one
6. The control device for an internal combustion engine according to claim 5, wherein the target increase rate of the opening is used when the change in the opening calculated by the at least one means is excluded . The control apparatus for an internal combustion engine according to any one of claims 1 to 6, wherein the forcible operation includes an operation to retard the ignition timing . The control apparatus for an internal combustion engine according to claim 7, wherein the operation toward the retard side is a most retarded angle operation . The control device for an internal combustion engine according to claim 1, wherein the forcible operation includes an operation for reducing a fuel injection amount to the engine. The control device for an internal combustion engine according to claim 9, wherein the reducing operation is an operation of stopping fuel injection .

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