JP3859809B2 - Intake air amount control device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake air amount control device that mainly controls an intake air amount during idling of an internal combustion engine, and relates to a device that controls the intake air amount during idling operation or deceleration operation, that is, controls the idling speed. It is.
[0002]
[Prior art]
As a conventional idling engine speed control device for an internal combustion engine, a target engine speed is determined according to the engine warm-up state such as the engine temperature, and the intake air amount is feedback-controlled so that the actual engine speed matches the target engine speed. Devices are known. In addition, in an intake air amount control device that performs control by switching between feedback control and open loop control without feedback according to various operating conditions of the engine, the throttle valve is fully closed while the vehicle is decelerating and is open loop control. For example, a method of obtaining a correction amount of the intake air amount corresponding to the engine speed at the moment when the state is reached, increasing the intake air amount by the correction amount, and thereafter gradually decreasing the correction amount. This is already known from Japanese Patent Publication No. 62-40536.
[0003]
[Problems to be solved by the invention]
In such a device, when the engine is idling (racing), or when the supply intake air amount suddenly changes from the load operation state where the throttle is depressed to the throttle open engine brake state, the negative pressure in the intake pipe is reduced. Oil rises and afterburn occurs due to sudden rise.
[0004]
In addition, the possibility of causing a temporary decrease in exhaust gas purification performance, engine rotation malfunction, or engine stall (so-called engine stall) due to a delay in feedback control is increased, which adversely affects the driving feeling of the vehicle.
[0005]
As a method for solving such a problem, conventionally, a correction amount of the intake air amount is defined according to the engine speed at the moment when the throttle valve of the engine changes to the fully closed state, and the intake air amount by this correction amount To increase.
[0006]
However, even in such a conventional method, for example, when the flow path volume from the throttle valve to the cylinder is large due to the configuration of the engine, for example, a supercharger is provided downstream of the throttle valve, and the flow path path becomes long. In such a case, since the flow path volume increases, the behavior of the engine speed corresponding to the change of the throttle valve becomes duller than that of a small flow path volume.
[0007]
Further, in such an engine, the method of increasing the intake air correction amount according to the engine speed at the time of deceleration determination without taking into account the engine operating state before the deceleration determination as in the conventional example, the engine intake air amount There was a problem that the behavior of the engine speed after the increase became unstable and the engine stalled in the worst case.
[0008]
The present invention has been made to solve the above-described problems, and optimizes the intake air amount by the intake air amount control device when the vehicle decelerates, causing a drop in engine speed and a feeling of idling to the vehicle. An object is to obtain an intake air amount control device for an internal combustion engine that does not.
[0009]
[Means for Solving the Problems]
An intake air amount control device for an internal combustion engine according to a first aspect of the present invention includes an intake air amount control means for adjusting the intake air amount of the internal combustion engine and the throttle valve of the internal combustion engine from an open state to a substantially fully closed state. Detected by the fully closed detection means for detecting the transition, the rotational speed detection means for detecting the rotational speed of the internal combustion engine, and the rotational speed detection means Of the internal combustion engine The number of revolutions has decelerated from above the prescribed number of revolutions to below the prescribed number of revolutions. Rotational speed deceleration detecting means for detecting And a first intake air correction amount for calculating a first intake air correction amount for increasing the intake air amount at the moment when the throttle valve is detected to be substantially fully closed by the fully closed detection means. Computing means; From the moment when the throttle valve is detected to be substantially fully closed by the fully closed detection means, From the rotation speed deceleration detecting means Of the internal combustion engine When the number of rotations decelerates from a specified value to a specified value Corresponding to the maximum value of the rotation speed detected by the rotation speed detection means until detection, A second intake air correction amount calculating means for calculating a second intake air correction amount for increasing the intake air amount; as well as Obtained from the second intake air correction amount calculation means The first and second And an intake air amount increasing means for increasing the intake air amount to the internal combustion engine in accordance with the intake air correction amount.
[0013]
Claim 2 In the intake air amount control device for an internal combustion engine according to the present invention, the first intake air correction amount calculating means detects the first intake air correction amount calculating means at the moment when the fully closed detecting means detects that the throttle valve is substantially fully closed. The first After the intake air correction amount is set to a first predetermined value, the first predetermined value is held for a first predetermined period, and then decreased to zero by a first predetermined decrease amount at each first predetermined timing. It is.
[0014]
Claim 3 In the intake air amount control apparatus for an internal combustion engine according to the invention, the first intake air correction amount calculating means is the first intake air correction amount calculating means when the throttle valve is detected to be substantially fully closed by the fully closed detecting means. At least one of the predetermined value, the first predetermined period, the first predetermined timing, and the first predetermined decrease amount is changed according to the rotational speed detected by the rotational speed detecting means.
[0015]
Claim 4 In the intake air amount control device for an internal combustion engine according to the invention, the second intake air correction amount calculation means decelerates the rotation speed from a predetermined rotation speed to a predetermined rotation speed by the rotation speed deceleration detection means. At the moment of judgment, The second The intake air correction amount is set to a second predetermined value, and after the second predetermined value is held for a second predetermined period, the second predetermined decrease amount is decreased to zero at each second predetermined timing. is there.
[0016]
Claim 5 In the intake air amount control device for an internal combustion engine according to the invention, the second intake air is determined at a moment when it is determined that the rotational speed from the rotational speed deceleration detecting means has decreased from a predetermined rotational speed to a predetermined rotational speed. The correction amount calculating means determines at least one of the second predetermined value, the second predetermined period, the second predetermined timing, and the second predetermined decrease amount according to the rotational speed detected by the rotational speed detecting means. To change.
[0017]
The intake air amount control device for an internal combustion engine according to claim 6 further includes load detection means for detecting whether the internal combustion engine is in no-load operation or in load operation, and the load detection means Is a compressor operation signal of an air conditioner, which is a load driven by the internal combustion engine, an operation signal of a power steering, an electric load operation signal attached to a vehicle, and an operation signal of a generator driven by the internal combustion engine. A signal detection function for detecting at least one of them, and a vehicle travel determination function for determining whether the vehicle is running or stopped, a detection signal by the signal detection function, or the vehicle travel determination function Or at least one of the first predetermined value, the first predetermined period, the first predetermined timing, and the first predetermined decrease amount, or the second predetermined value. , Changing at least one of the second predetermined period, the second predetermined timing, and the second predetermined decrease amount. Is.
[0018]
An intake air amount control device for an internal combustion engine according to the invention of claim 7 is characterized in that the load detection means. The vehicle travel determination function detects the travel speed of the vehicle, detects that the transmission is blocking torque transmission or torque transmission between the internal combustion engine and the wheels, the vehicle speed is equal to or higher than a predetermined value, and When the transmission detects torque transmission between the internal combustion engine and the wheels, it determines that the vehicle is running under load operation. Is.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram showing the overall configuration of the internal combustion engine according to the present embodiment. In FIG. 1, reference numeral 1 denotes a known four-cycle spark ignition type engine, which mainly sucks combustion air through an air cleaner 2, an intake pipe 3, a throttle valve 7, a surge tank 4, and an intake manifold.
[0021]
The fuel is supplied from a fuel system (not shown) through an injector 5 provided in the intake manifold. The throttle opening θ of the throttle valve 7 is detected by a throttle sensor 8 and a signal corresponding to the throttle opening θ is output. The fully closed throttle valve 7 is detected by an idle switch 9 and outputs an ON / OFF signal.
[0022]
A bypass air passage 11 that bypasses the throttle valve 7 is connected to the intake pipe 3 upstream and downstream of the throttle valve 7 of the intake pipe 3. The bypass air passage 11 is provided with a bypass air control valve 10 that controls the opening cross-sectional area of the bypass air passage 11. The bypass air whose flow rate is controlled by the bypass air control valve 10 is taken into the engine 1 through the bypass air passage 11 as combustion air.
[0023]
6 is a semiconductor type pressure sensor provided in the surge tank 4 for measuring the amount of air taken into the engine 1, 14 is a thermistor type water temperature sensor for detecting the cooling water temperature of the engine 1, 15 is an exhaust pipe, 12 Is a crank angle sensor that outputs a pulse signal corresponding to the crank angle of the engine 1, 16 is a vehicle speed sensor that outputs a pulse signal having a frequency proportional to the rotational speed of the wheel shaft, and 13 is a signal from the electronic control unit 19. Spark plugs that are controlled and installed to fly sparks for each cylinder of the engine 1, 17 is a battery that supplies voltage to the electronic control unit 19, and 18 is a battery voltage that is supplied to the electronic control unit 19. An ignition key switch 19 that is turned off is an electronic control unit 19 that controls the driving of the engine 1.
[0024]
The electronic control unit 19 uses each input information from the crank angle sensor 12, the pressure sensor 6, the water temperature sensor 14, the vehicle speed sensor 16 and the like by a well-known method to determine the fuel injection amount and bypass air amount of the engine 1 and the optimum amount. The ignition timing is calculated, the injector 5 is controlled to inject fuel for a predetermined time corresponding to the calculated fuel injection amount, and the bypass air control valve 10 is controlled to obtain the calculated bypass air amount. Then, the ignition plug 13 is controlled so that the calculated optimal ignition timing is obtained, and the drive control of the engine 1 is performed.
[0025]
FIG. 2 is a detailed block diagram of the electronic control unit 19. In the figure, reference numeral 100 denotes a microcomputer. The microcomputer 100 converts a counter 201 for measuring the rotation period of the engine 1, a timer 202 for measuring drive times of various outputs, and converts an analog input signal into a digital signal. A / D converter 203, an input port 204 for inputting a digital signal and transmitting it to the CPU 200, a RAM 205 as a work memory, and programs shown in the flowcharts shown in FIGS. A ROM 206, an output port 207 for outputting a command signal of the CPU 200, and a common bus 208 for connecting and receiving the components of the microcomputer 100 to exchange data are included.
[0026]
Reference numerals 101 to 103 denote first to third input interfaces for inputting signals to the microcomputer 100 from the sensors 6, 8, 9, 12, 14 and 16, and 104 denotes a control signal calculated by the microcomputer 100 to the injector 5 and bypass. An air interface valve 10 and an output interface circuit for outputting to the spark plug 13, 105 is a first power supply circuit that converts the battery voltage input through the ignition key switch 18 into a constant voltage and supplies it to the microcomputer 100.
[0027]
Here, the signal from the crank angle sensor 12 input to the first input interface circuit 101 is subjected to waveform shaping or the like and converted to an interrupt signal and input to the microcomputer 100. Each time this interrupt signal is generated, the CPU 200 of the microcomputer 100 reads the value of the counter 201 and calculates the cycle of the engine rotation from the difference between the read value and the previously read value and stores it in the RAM 205. .
[0028]
The second input interface circuit 102 removes noise components from the analog output signals from the input pressure sensor 6, throttle sensor 8, water temperature sensor 14, etc., and outputs the signal to the A / D converter 203. Is.
[0029]
The third input interface circuit 103 converts the level of the input ON / OFF signal such as the idle switch 9 and the pulse signal from the vehicle speed sensor 16 into a digital signal level and outputs it to the input port 204.
[0030]
The output interface circuit 104 performs processing such as amplification on the drive output input from the output port 207 and outputs it to the injector 5, the bypass air control valve 10, the spark plug 13, and the like. The first power supply circuit 105 receives the voltage from the battery 17 when the key switch 18 is ON, converts it to a constant voltage, and supplies it to the microcomputer 100. Thereby, the microcomputer 100 starts operation. Here, the microcomputer 100 includes an intake air amount control means, a fully closed detection means, a rotation speed detection means, a rotation speed deceleration detection means, first and second intake air correction amount calculation means, an intake air amount increase means, Load detection means Respectively.
[0031]
Next, the operation of the present embodiment will be described with reference to the flowchart of FIG. First, after initial settings such as the RAM 205, timer 202, and interrupt setting of the microcomputer 100 are performed, the process proceeds to step S301. In step S301, rotation speed data Ne representing the engine rotation speed NE is obtained from the crank angle period already detected in the crank angle signal interruption process from the crank angle sensor 12.
[0032]
In step S302, a throttle opening value TH representing the throttle opening θ detected by the throttle sensor 8, an intake pipe pressure value Pb representing the intake pipe pressure PB detected by the pressure sensor 6, and the like are read. In step S303, based on the previously read data (Ne, TH, Pb, etc.), processing of other control (control of fuel supply, ignition timing, etc. is performed although details are not described) is performed.
[0033]
In step S304, the control amount calculation processing of the bypass air control valve 10 whose details are shown in the flowchart of FIG. 4 based on the previously read data (Ne, the ON / OFF signal of the idle switch 9, the pulse signal of the vehicle speed sensor 16, etc.). I do. After the process of step S304, the process returns to step S301 to repeat the above operation.
[0034]
Next, detailed processing of the control amount calculation processing of the bypass air control valve 10 in step S304 in FIG. 3 will be described with reference to FIG. First, in step S401, a basic bypass air amount QBASE for maintaining the target rotational speed in accordance with the operation state of the engine 1 (warm-up state and the like are not described in detail) is set, and the process proceeds to step S402 and the idle switch 9 is turned on. It is determined whether it is in the idle state.
[0035]
If it is ON, the process proceeds to step S403, and it is determined whether or not the idle switch 9 was ON when the same process was executed last time. That is, the change of the idle switch 9 is determined in steps S401 and S402. If the idle switch 9 was previously turned on, that is, if there was no change in the idle state, the process proceeds to step S404.
[0036]
Further, if the idle switch 9 is OFF in the previous step S403, that is, if it is determined that the idle state has changed from a state other than the idle state, the process proceeds to step S409, and the first-stage bypass air correction as the first predetermined value is performed. An amount (dashpot amount) QDP and a holding time TDP as a first predetermined period are set. In this embodiment, a constant value XQDP1 (for example, 12 [l / min]) and XTDP1 (for example, 8, a 25 msec down counter is used in this embodiment and the holding time is 2 [sec]) are substituted. The processing from step S401 to step S409 fulfills the function of the first intake air correction amount calculation means.
[0037]
In step S410, the engine speed maximum value NeMAX related to the dashpot amount in the next stage is initialized to the current Ne, and the process proceeds to step S411. In step S404, the current Ne is compared with NeMAX. If the current Ne is greater than NeMAX, the process proceeds to step S405, NeMAX is updated, and the process proceeds to step S406. If the current Ne is smaller than NeMAX, the process proceeds to step S406.
[0038]
In step S406, it is determined whether or not the rotation speed condition is satisfied, that is, whether or not the current Ne is a predetermined value (for example, 1500 [rpm]) or more, and when the condition is satisfied, that is, when the rotation speed is equal to or higher than the predetermined rotation speed. Advances to step S411. When the condition is not satisfied, the process proceeds to step S407, and it is determined whether or not the rotation speed condition is satisfied last time. If the condition is satisfied, the process proceeds to step S408.
[0039]
In steps S406 and S407, it is determined that the rotational speed has changed from a predetermined rotational speed to a following rotational speed. In step S408, a second-stage dashpot amount QDP as a second predetermined value and a holding time TDP as a second predetermined period are set. In the present embodiment, the values XQDP2 and XTDP2 corresponding to NeMAX until the rotation speed changes from the predetermined rotation speed to the following are set. Here, the relationship between NeMAX and XQDP2 and XTDP2 is as shown in FIGS. The processing from step S404 to step S408 fulfills the function of the second intake air correction amount calculation means.
[0040]
That is, the dashpot amount XQPD2 and the holding time XTDP2 corresponding to the maximum rotational speed value NeMAX from when the idle switch 9 is turned on until the rotational speed becomes equal to or lower than the predetermined rotational speed are set, and the process proceeds to step S411. On the other hand, if it is determined in step S407 that the rotation speed condition has not been satisfied last time, the process proceeds to step S411.
[0041]
Next, in step S411, a correction amount Qetc other than the dashpot amount (a feedback amount corresponding to the difference between the target rotational speed and the actual rotational speed, details of load correction when the air conditioner is connected, etc. is not described). The process proceeds to step S412. In step S412, the bypass air amount QISC is obtained by adding the basic bypass air amount QBASE, the dashpot amount QDP, and the other correction amount Qetc, and the process proceeds to step S414.
[0042]
On the other hand, if it is determined in step S402 that the idle switch 9 is OFF, that is, it is determined that it is other than idle, Step S413 The process proceeds to step S414 with the bypass air amount QISC as the basic bypass air amount QBASE. Further, since the stepper motor type bypass air control valve 10 is used in the present embodiment, in step S414, the control amount of the bypass air control valve 10 corresponding to the bypass air amount QISC, that is, Target motor position In order to obtain P, the target motor position P is obtained from the QISC map shown in FIG. 9, and the control amount calculation process of the bypass air control valve 10 is terminated.
[0043]
FIG. 10 is a drive processing routine of the bypass air control valve 10 according to the control amount of the bypass air control valve 10 calculated in the routine, that is, the target motor position P, and is executed every 10 msec, for example. First, in step S1001, the actual position of the bypass air control valve 10 is read, and the process proceeds to step S1002.
[0044]
In step S1002, the target position P calculated in the control amount calculation routine of the bypass air control valve 10 is compared with the actual position. If it is determined that they are equal, the bypass air control valve drive routine is terminated as it is. To do. If it is determined in step S1002 that the target position P is smaller than the actual position, the process proceeds to step S1003, the bypass air control valve 10 is driven to the closed side by one step, and the bypass air control valve drive routine is ended.
[0045]
If it is determined in step S1002 that the target position P is larger than the actual position, the process proceeds to step S1004, the bypass air control valve 10 is driven to the open side by one step, and the air control valve drive routine is terminated. In this way, the bypass air control valve 10 is driven to open or close step by step each time the bypass air control valve drive routine is executed. If it is determined in step S1002 that the target position P is equal to the actual position, the bypass air control valve drive routine is terminated.
[0046]
FIG. 5 is a timer processing routine for performing processing of timers and the like (not described in detail) used in the various processes described above, and is executed, for example, every 25 msec as the first and second predetermined timings. It is. First, in step S501, 1 is subtracted every 25 msec from the timer TDP (holding time 2 sec: 2000), and the process proceeds to step S502 to compare with zero. If it is determined that the value is equal to or less than zero, the process proceeds to step S503, where zero is substituted for the timer TDP, and the timer process is terminated. Thereby, the holding elapsed time of the first or second intake air correction amount (XQDP1, XQDP2) is determined.
[0047]
If it is determined in step S502 that the timer TDP is equal to or greater than zero, the timer processing routine is ended there, and 1 is subtracted from the timer TDP in the next timer processing routine. Thus, the timer TDP is processed in this processing routine.
[0048]
Through this timer processing routine, the first and second predetermined values, intake air correction amounts XQDP1, 2 (set in steps S409 and S408 in FIG. 4) are held. Perform the action.
[0049]
FIG. 6 is a routine for performing subtraction processing for each dashpot amount which is the first or second intake air correction amount set in the control amount calculation processing routine of the bypass air control valve 10. In the embodiment, the routine is executed every 500 msec which is the first or second predetermined timing.
[0050]
First, in step S601, it is determined whether or not the timer TDP is zero from the timer processing routine, that is, whether or not the holding time has elapsed. If the timer TDP is not zero, the dashpot amount subtraction routine is directly executed. The process waits until the timer TDP becomes zero in the next dashpot amount subtraction routine. If the timer TDP is zero in step S601, the process proceeds to step S602, and the dashpot amount QDP is subtracted by a predetermined value that is the first or second predetermined decrease amount (3 [l / min] in the present embodiment). Then, the process proceeds to step S603.
[0051]
In step S603, the dashpot amount QDP is compared with zero. If it is determined that the dashpot amount QDP is equal to or greater than zero, the dashpot amount subtraction routine is terminated as it is. If it is determined in step S603 that the dashpot amount QDP is less than or equal to zero, the process proceeds to step S604 where zero is substituted for the dashpot amount QDP and the dashpot amount subtraction routine is terminated. As a result, the bypass air amount QISC in step S412 (see FIG. 4) decreases every 500 msec, and the control amount of the bypass air control valve 10 can converge to 0 after a predetermined time in step S414.
[0052]
Here, FIGS. 11 and 12 are time charts supplementarily explaining the operation at the time of deceleration of the vehicle according to the flowchart. The throttle valve opening TH with respect to the time axis, the idle switch signal, the engine speed Ne, and the bypass air amounts QISC1 and 2 are shown. It shows the behavior.
[0053]
First, FIG. 11 is a time chart when the driver depresses the accelerator to an open state, that is, when the throttle valve 7 is changed from a certain opening to a fully closed state, and the dotted line in the behavior of the rotational speed Ne indicates the bypass air amount. This is the rotational speed behavior when the amount is not increased. The solid lines (circle 1) and (circle 2) in the behavior of the rotation speed Ne indicate the rotation speed when the bypass air amount is increased as in the conventional example (circle 1) and this embodiment (circle 2), respectively. This is the behavior of Ne.
[0054]
Here, the behavior of the rotational speed Ne when the amount of bypass air is not increased drops once and then reaches the target rotational speed (800 rpm). At this time, the negative pressure in the intake pipe suddenly rises, resulting in oil rise, afterburn, exhaust gas deterioration, and the like. In order to eliminate this problem, in the conventional example, when the throttle valve 7 is in a fully closed state, that is, at the moment when the idle switch 9 changes from OFF to ON (time t1), the amount of bypass air depends on the rotational speed A at that time. QISC1 is increased as shown in FIG. 11 (circle 1). Therefore, as shown in FIG. 11 (circle 1), the behavior of the rotational speed Ne is set to the target rotational speed (800 rpm) along the amount of decrease in the bypass air amount QISC1 from a value far exceeding the target rotational speed (800 rpm). Transition to.
[0055]
However, according to the present embodiment, the time t1 when the throttle valve 7 is fully closed and the moment (time t2) when the rotational speed becomes equal to or lower than the predetermined rotational speed (1500 rpm) are shown in FIG. The bypass air amount QISC2 is increased as shown in circles 2), b), and c, and the behavior of the rotational speed Ne is shorter in time than (circle 1) as shown in (circle 2) in FIG. It converges to the target speed.
[0056]
FIG. 12 shows a case where the throttle valve 7 is changed from fully closed to fully open to fully closed earlier than FIG. 11, and at the time t1, that is, the instant when the idle switch 9 changes from OFF to ON. Then, as in FIG. 11, the bypass air amount QISC1 is increased as shown in FIG. 12 (circle 1) according to the rotational speed A at time t1, so the rotational speed Ne is as shown in FIG. 12 (circle 1). In addition, once it falls, it converges to the target rotational speed after a predetermined time while changing the rotational speed in the ± direction around the target rotational speed (800 rpm).
[0057]
However, according to the method of the present embodiment, the increased amount (circle a) of the bypass air amount QISC2 at the time t1 is the same as that in FIG. 11, but the moment when the rotational speed becomes the predetermined rotational speed (1500 rpm) or less. The amount of increase in the bypass air amount QISC2 at (time t2) (circle b) becomes an amount corresponding to the rotational speed B different from FIG. 11, and the behavior of the rotational speed Ne is short as shown in FIG. 12 (circle 2). It converges to the target speed over time. Thus, in the conventional example, only the same correction of the bypass air amount QISC1 can be performed in both FIGS. 11 and 12, so that the convergence to the target rotational speed is delayed in FIG. 11, and the phenomenon of lowering the target rotational speed in FIG. 12 occurs. .
[0058]
Also, the phenomenon shown in (circle 1) of FIG. 12 increases as the flow path volume from the throttle valve 7 to the cylinder of the engine 1 increases. However, in this embodiment, since the subsequent convergence to the target rotational speed can be corrected accurately and quickly while suppressing the increase in the negative pressure in the intake pipe, there is no danger of engine stall, and the driving feeling is improved.
[0059]
Further, in the present embodiment, whether or not the throttle valve 7 is fully closed is determined by the idle switch 9, but the present invention does not limit the fully closed detection means, and the throttle valve 7 is substantially fully closed. For example, the determination may be made based on the detection value of the throttle opening sensor 8, or the detection value of either the intake air amount or the intake pipe pressure may be compared with a predetermined value. Good.
[0060]
Further, the present embodiment describes the operation process for correcting the intake air amount change with respect to the sudden change of the throttle valve 7, and includes a change from a low opening degree of the throttle valve 7 to a fully closed state per unit time. When the change of the throttle valve 7 is small, the intake air amount may not be corrected.
[0061]
In this embodiment, a stepper motor type bypass air control valve 10 for controlling the opening cross-sectional area of the bypass air passage 11 is used as the intake air amount control means. For example, a linear solenoid type bypass air control valve in which the flow rate changes in proportion to the input current, or a control valve that controls the air flow rate with the ON / OFF duty ratio of the input current may be used.
[0062]
In the present embodiment, the engine speed is equal to or higher than the predetermined speed for detecting the behavior of the engine speed as to whether the engine speed has been reduced to a predetermined speed (1500 rpm) or less after the throttle valve 7 is substantially fully closed. The second air correction is performed after setting the second dashpot amount QDP and the second timer value TDP corresponding to the maximum rotational speed value NeMAX until it is determined that the vehicle tends to decelerate from the predetermined rotational speed to the predetermined rotational speed or less. The quantity Qetc was calculated.
[0063]
However, the deviation at a predetermined timing of the engine speed is calculated and stored in the RAM 205, and the deviation stored when it is determined that the engine speed tends to decelerate from the predetermined speed to the predetermined speed is stored in the RAM 205. The second air correction amount Qetc may be calculated after reading out and setting the second dashpot amount QDP and the second timer value TDP corresponding to this deviation.
[0064]
Alternatively, when it is determined that the rotational speed tends to decelerate, each deviation stored in the RAM 205 is read to obtain a moving average value of these deviations, and the second dashpot amount QDP, After setting the second timer value TDP, the second air correction amount Qetc may be calculated.
[0065]
Furthermore, after setting the second dashpot amount QDP and the second timer value TDP corresponding to the time when it is determined that the engine speed has decreased from the predetermined speed to the predetermined speed, the second dashpot amount QDP is set. The air correction amount Qetc may be calculated.
[0066]
Further, in the present embodiment, the timing for setting the second-stage dashpot amount is set to a predetermined rotational speed (1500 rpm), but the present invention does not limit this timing to the predetermined rotational speed, and the engine rotational speed is Any timing may be used as long as the intake air amount can be corrected in advance so as not to drop below the target rotational speed. For example, it has means for setting the target rotational speed according to at least the warm-up state of the engine, obtains a deviation between the actual rotational speed and the target rotational speed, and at the moment when the deviation becomes a predetermined value or less, You may make it set the amount of dashpots of eyes.
[0067]
Embodiment 2. FIG.
The first embodiment is configured to set the constant values XQDP and XTDP for the dashpot amount set value and the holding time when the throttle valve is fully closed (first stage) regardless of the engine operating state at that time. The constant value is set so that the negative pressure in the intake pipe can be prevented from abruptly rising and the influence on the engine speed after the throttle valve is fully closed is minimized.
[0068]
However, in the first embodiment, the setting value and the holding time of the dashpot amount when the engine speed is reduced (second stage) are configured to change according to the deceleration of the engine speed after the throttle valve is fully closed. Therefore, when the deceleration of the engine speed is large, such as when decelerating from high-speed rotation, the intake air amount is corrected in a large amount in a short time.
[0069]
Therefore, if the intake air amount cannot be corrected in a large amount in a short time due to factors such as the maximum flow rate of the intake air amount control means and the operating speed, the dashpot amount QDP in the second stage will be excessive or insufficient. As a result, the problem of poor convergence of the engine speed to the target speed occurs.
[0070]
For such a phenomenon, in the configuration of the first embodiment, the first-stage dashpot amount set value QDP and the holding time TDP described in step S409 of FIG. A value corresponding to the number of revolutions, for example, a value as shown in FIGS.
[0071]
As a result, the amount of intake air corrected when the throttle is fully closed is appropriately increased according to the rotation speed when the throttle is fully closed, and the amount of increase is set to the setting value and holding time of the second stage dashpot amount. Can be set as shown by the broken lines in FIG. 7 (circle a) and FIG. 8 (circle a), for example. Therefore, even when the intake air amount cannot be corrected in a large amount in a short time, the convergence of the engine speed to the target speed can be performed quickly and accurately.
[0072]
In the present embodiment, the value to be changed according to the rotation speed when the throttle is fully closed is the first dashpot amount setting value and the holding time. However, the present invention sets the changing value to the setting value and the holding time. The intake air amount corrected after the throttle is fully closed may be increased or decreased according to the rotation speed when the throttle is fully closed. For example, the dashpot amount subtraction process in FIG. 6 described in the first embodiment may be changed from 100 msec to 1 sec depending on the rotation speed when the throttle is fully closed, instead of defining every 500 msec. . Further, the predetermined amount of reduction in step S602 in the dashpot amount subtraction process shown in FIG. 6 (3 [l / min] in the first embodiment) may be changed according to the rotation speed when the throttle is fully closed. Good.
[0073]
Embodiment 3 FIG.
In the first and second embodiments, the correction of the intake air amount does not take into account whether or not the operating state of the engine 1 is unloaded. For example, a compressor load of an air conditioner is connected to the engine, and the load Is driven by the engine 1, the deceleration of the engine speed after the throttle valve is fully closed increases from the time of no load.
[0074]
Therefore, if the intake air amount is corrected with the configuration of the first and second embodiments without considering the load connected to the engine 1, the engine speed may be lower than the target speed. For such a phenomenon, the operation signals of the load detection means, for example, the compressor of the air conditioner, in the configuration of the first and second embodiments are sent to the microcomputer 100 of the electronic control unit 19 shown in FIGS. By inputting through the third input interface 103 and the input port 204, the intake air correction amount can be switched according to the operation signal of the compressor.
[0075]
For example, if the compressor is in operation, the value indicated by the characteristic of (circle a) in FIG. 13 is used instead of XQDP1 set in step S409 in the flowchart of FIG. 4 when setting the dashpot amount in the first stage. If the setting is made and the compressor is not in operation, the intake air amount can be corrected more accurately if the setting is made as in step S409 in FIG.
[0076]
In the present embodiment, the value to be changed according to the load detection is only the setting value for the first-stage dashpot amount, but the present invention sets the value to be changed to the first-stage dashpot amount setting. The value is not limited to a value, and it is sufficient that the intake air correction amount can be increased or decreased according to the load state of the engine during which the intake air amount correction is being performed.
[0077]
For example, first stage dashpot amount holding time, dashpot amount subtraction processing timing, dashpot amount subtraction amount, or second stage dashpot amount setting value, holding time, dashpot amount subtraction processing The timing may be changed by combining any one or more of the dashpot amount subtraction amounts.
[0078]
In the present embodiment, the load detection means is not limited to the operation signal of the air conditioner, and it is only necessary to detect the presence or absence of a load connected to the engine 1, for example, a power assist execution signal of a vehicle equipped with a power steering. (For example, a hydraulic switch provided in a hydraulic circuit in the case of a hydraulic type, or a motor drive signal in the case of an electric type), a switch input signal of an electric load (for example, a headlight, a rear defogger, etc.) attached to the vehicle Alternatively, the same result as described above can be obtained by taking in a power generation operation signal (field coil excitation signal) of a generator connected to the vehicle.
[0079]
Further, when the vehicle is traveling, it may be determined that the engine 1 is under load operation, and the dashpot amount may be changed. A transmission that transmits / cuts off the torque of the engine 1 to / from the drive wheels (neutral) is provided, and when the transmission of torque is selected to be cut off by this transmission, that is, when shifted to neutral, shifts to other than neutral. When the switch is turned on, a switch that is turned off is provided, and a status signal of the switch is input to the CPU 200 through the third input interface circuit 103 and the input port 204.
[0080]
Then, the signal from the vehicle speed sensor 16 is monitored every predetermined timing (600 [msec]) while the OFF state signal is input, and when the signal is input from the vehicle speed sensor 16 even once during the predetermined timing, the vehicle Even if it is determined that the vehicle is traveling and the dashpot amount setting value, the holding time, the dashpot amount subtraction process timing, the dashpot amount subtraction amount, or a combination of a plurality of dashpot amount subtraction amounts are changed in combination, the same as above Result is obtained.
[0081]
【The invention's effect】
According to the first aspect of the present invention, the intake air amount control means for adjusting the intake air amount of the internal combustion engine and the fully closed state that detects that the throttle valve of the internal combustion engine has shifted from the open state to the substantially fully closed state. Detected by a detection means, a rotation speed detection means for detecting the rotation speed of the internal combustion engine, and the rotation speed detection means Of the internal combustion engine The number of revolutions has decelerated from above the prescribed number of revolutions to below the prescribed number of revolutions. Rotational speed deceleration detecting means for detecting And a first intake air correction amount for calculating a first intake air correction amount for increasing the intake air amount at the moment when the throttle valve is detected to be substantially fully closed by the fully closed detection means. Computing means; From the moment when the throttle valve is detected to be substantially fully closed by the fully closed detection means, From the rotation speed deceleration detecting means Of the internal combustion engine When the number of rotations decelerates from a specified value to a specified value Corresponding to the maximum value of the rotation speed detected by the rotation speed detection means until detection, A second intake air correction amount calculating means for calculating a second intake air correction amount for increasing the intake air amount; as well as Obtained from the second intake air correction amount calculation means The first and second Intake amount increasing means to increase the intake air amount to the internal combustion engine according to the intake air correction amount, preventing exhaust gas deterioration, oil increase, afterburn etc. due to excessive intake manifold negative pressure It is possible to obtain an excellent effect that the engine speed can be smoothly converged to the target speed.
[0085]
Claim 2 According to the invention, at the moment when the fully closed detection means detects that the throttle valve is substantially fully closed, the first intake air correction amount calculating means is The first After the intake air correction amount is set to the first predetermined value, the first predetermined value is held for a first predetermined period, and then decreased to zero by a first predetermined decrease amount at each first predetermined timing. As a result, the rotational speed of the internal combustion engine can be smoothly converged to the target rotational speed.
[0086]
Claim 3 According to this invention, the first intake air correction amount calculating means is the first predetermined value and the first predetermined moment at the moment when the fully closed detecting means detects that the throttle valve is substantially fully closed. Since at least one of the period, the first predetermined timing and the first predetermined decrease amount is changed according to the rotational speed detected by the rotational speed detecting means, the rotational speed of the internal combustion engine is changed to the target rotational speed. It is possible to converge smoothly.
[0087]
Claim 4 According to the present invention, at the moment when the second intake air correction amount calculating means determines that the rotational speed has been reduced from the predetermined rotational speed to the predetermined rotational speed by the rotational speed deceleration detecting means. The second The intake air correction amount is set to a second predetermined value, and after the second predetermined value is held for a second predetermined period, the second predetermined decrease amount is decreased to zero at each second predetermined timing. Therefore, there is an effect that the rotational speed of the internal combustion engine can be smoothly converged to the target rotational speed in a short time.
[0088]
Claim 5 According to the invention, at the moment when it is determined that the rotational speed from the rotational speed deceleration detecting means has decelerated from a predetermined rotational speed to a predetermined rotational speed, the second intake air correction amount computing means is Since at least one of the predetermined value of 2, the second predetermined period, the second predetermined timing, and the second predetermined decrease amount is changed according to the rotational speed detected by the rotational speed detection means, There is an effect that the rotational speed of the internal combustion engine can be smoothly converged in a short time by the target rotational speed.
[0090]
Claim 6 According to the invention of Load detecting means for detecting whether the internal combustion engine is in no-load operation or in load operation; The load detection means includes a compressor operation signal of an air conditioner that is a load driven by the internal combustion engine, a power steering operation signal, an electric load operation signal attached to a vehicle, and a generator driven by the internal combustion engine. A signal detection function for detecting at least one of the operation signals and a vehicle travel determination function for determining whether the vehicle is running or stopped, and a detection signal by the signal detection function or the vehicle Based on the vehicle travel determination result by the travel determination function, at least one of the first predetermined value, the first predetermined period, the first predetermined timing, and the first predetermined decrease amount is changed, or the second At least one of the predetermined value, the second predetermined period, the second predetermined timing, and the second predetermined decrease amount is changed. There is an effect that can be reduced to the target rotational speed a rotational speed more smoothly if so as to set the intake air correction amount during the deceleration Te.
[0091]
Claim 7 According to the invention, the vehicle travel determination function of the load detection means detects the travel speed of the vehicle and also detects that the transmission is blocking torque transmission or torque transmission between the internal combustion engine and the wheels. In addition, since it is determined that the vehicle speed is equal to or higher than the predetermined value and the transmission is running on the vehicle by load driving when the transmission of torque between the internal combustion engine and the wheels is detected, the vehicle can be smoothly operated even during load driving of the vehicle. There is an effect that the rotational speed can be reduced to the target rotational speed.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing an intake air amount control device for an internal combustion engine according to an embodiment of the present invention;
FIG. 2 is a configuration diagram of an electronic control unit of the present invention.
FIG. 3 is a flowchart for explaining processing contents in the electronic control unit of the present invention;
FIG. 4 is a flowchart for explaining the contents of a control amount calculation process of the bypass air control valve of the present invention.
FIG. 5 is a flowchart for explaining the contents of timer processing according to the present invention;
FIG. 6 is a flowchart for explaining the contents of a dashpot amount subtraction process according to the present invention.
FIG. 7 is a characteristic diagram for explaining a relationship between an engine speed maximum value and a second-stage dashpot setting value according to the embodiment of the present invention.
FIG. 8 is a characteristic diagram for explaining the relationship between the maximum engine speed and the second stage dashpot holding time according to the embodiment of the present invention.
FIG. 9 is a characteristic diagram showing a flow characteristic of the bypass air control valve according to the embodiment of the present invention.
FIG. 10 is a flowchart for explaining the contents of a bypass air control valve drive process of the present invention.
FIG. 11 is a time chart for explaining the operation of the embodiment of the invention.
FIG. 12 is a time chart for explaining the operation of the embodiment of the invention.
FIG. 13 is a characteristic diagram for illustrating the relationship between the engine speed maximum value and the first-stage dashpot setting value according to the embodiment of the present invention.
FIG. 14 is a characteristic diagram for illustrating the relationship between the maximum engine speed and the second-stage dashpot holding time according to one embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Internal combustion engine, 6 Pressure sensor, 7 Throttle valve, 9 Idle switch, 10 Bypass air control valve, 12 Crank angle sensor, 14 Water temperature sensor, 19
Electronic control unit.

Claims (7)

An intake air amount control means for adjusting the intake air amount of the internal combustion engine;
A fully-closed detecting means for detecting that the throttle valve of the internal combustion engine has shifted from an open state to a substantially fully-closed state;
A rotational speed detection means for detecting the rotational speed of the internal combustion engine;
A rotation speed reduction detection means for detecting that the rotation speed of the internal combustion engine detected by the rotation speed detection means has been reduced from a predetermined rotation speed to a predetermined rotation speed;
First intake air correction amount calculation means for calculating a first intake air correction amount for increasing the intake air amount at the moment when the throttle valve is detected as being substantially fully closed by the fully closed detection means. When,
From the moment when the throttle valve is detected to be substantially fully closed by the full-close detection means, the rotational speed of the internal combustion engine is decelerated from a predetermined rotation speed to a predetermined rotation speed by the rotation speed reduction detection means. The second intake air correction amount calculation for calculating the second intake air correction amount for increasing the intake air amount corresponding to the maximum value of the rotation number detected by the rotation number detection means until Means,
An intake air amount increasing means for increasing the intake air amount to the internal combustion engine in accordance with the first and second intake air correction amounts determined by the first and second intake air correction amount calculating means. An intake air amount control apparatus for an internal combustion engine. The first intake air correction amount calculation means sets the first intake air correction amount to a first predetermined value at the moment when the full-close detection means detects that the throttle valve is substantially fully closed. 2. The internal combustion engine according to claim 1, wherein after the setting, the first predetermined value is held for a first predetermined period, and then decreased to zero by a first predetermined decrease amount at each first predetermined timing. Engine intake air amount control device. The first intake air correction amount calculating means receives at least one of the first predetermined value, the first predetermined period, the first predetermined timing, and the first predetermined decrease amount from the fully closed detection means. 3. The intake air amount control for an internal combustion engine according to claim 2, wherein a change is made in accordance with the rotational speed detected by the rotational speed detection means at the moment when it is detected that the throttle valve is substantially fully closed. apparatus. The second intake air correction amount calculating means detects the second intake air at the moment when the rotational speed deceleration detecting means detects that the rotational speed of the internal combustion engine has decelerated from a predetermined rotational speed to a predetermined rotational speed. The air correction amount is set to a second predetermined value, and after the second predetermined value is held for a second predetermined period, the second predetermined decrease amount is decreased to zero at each second predetermined timing. The intake air amount control device for an internal combustion engine according to claim 1. The second intake air correction amount calculating means calculates at least one of the second predetermined value, a second predetermined period, a second predetermined timing, and a second predetermined decrease amount as the rotational speed deceleration detecting means. 5. The method according to claim 4, wherein the engine speed is changed according to the rotational speed detected by the rotational speed detection means at the moment when it is detected that the rotational speed of the internal combustion engine has decelerated from a predetermined rotational speed to a predetermined rotational speed. An intake air amount control device for an internal combustion engine according to claim 1. Load detecting means for detecting whether the internal combustion engine is in no-load operation or in load operation;
The load detecting means includes an air conditioner compressor operation signal, a power steering operation signal, an electric load operation signal attached to a vehicle, and a generator driven by the internal combustion engine. A signal detection function for detecting at least one of the operation signals and a vehicle travel determination function for determining whether the vehicle is traveling or stopped, and a detection signal by the signal detection function, or Based on the vehicle travel determination result by the vehicle travel determination function, at least one of the first predetermined value, the first predetermined period, the first predetermined timing, and the first predetermined decrease amount is changed, or the first second predetermined value, the second predetermined time period, no claim 2, characterized in that at least one change of the second predetermined timing and a second predetermined decrement Intake air amount control system for an internal combustion engine according to any of the 5. The vehicle travel determination function of the load detection means detects the travel speed of the vehicle and detects that the transmission is blocking torque transmission or torque transmission between the internal combustion engine and the wheels, and the vehicle speed is a predetermined value. 7. The intake air amount control apparatus for an internal combustion engine according to claim 6, wherein the transmission determines that the vehicle is running under load operation when torque transmission between the internal combustion engine and wheels is detected .

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