JP2009270483A - Control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely improve filling efficiency, without receiving influence of a variation in manufacture and a change with the lapse of time of an internal combustion engine, while satisfying a request for cost reduction and miniaturization. <P>SOLUTION: A highly responsive air flowmeter 14 whose output changes with excellent responsiveness in response to a change in the suction air volume, is arranged in an intake pipe 12 of an engine 11, and can detect intake pulsation and even a backflow. An intake opening-closing valve 18 is closed during a predetermined period determined by taking into consideration the relationship between an intake stroke and the intake pulsation timing of respective cylinder, actually, a period when a reflected wave (the backflow) of the intake pulsation from the intake valve 31 side reaches the intake opening-closing valve 18, and " intermittent closing control " for controlling so as to open the intake opening-closing valve 18, is performed in the other period. When performing this intermittent closing control, the closing timing TVID (and/or a closing period) of the intake opening-closing valve 18 is controlled by making a feedback process so as to reduce the intake pulsation detected from output of the air flowmeter 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an internal combustion engine that executes control for improving the charging efficiency of the internal combustion engine (engine).

  Conventionally, as a technique for improving the charging efficiency of an engine, a variable intake system that improves the charging efficiency by using the resonance supercharging or inertial supercharging effect by changing the intake pipe length according to the engine rotation speed is known. (For example, refer to Patent Documents 1 and 2).

In recent years, the number of engines equipped with a variable intake valve device that changes the valve timing and lift amount of intake air is increasing. This variable intake valve device is designed to maximize the amount of air charged in the cylinder when the throttle is fully opened. Controlled.
JP 2008-38759 A JP 2007-297963 A

  However, the conventional variable intake system has a complicated configuration, and the entire apparatus becomes large, so that the demand for cost reduction and size reduction cannot be satisfied.

  Moreover, the conventional control method for the variable intake system and the variable intake valve device only uses prospective control according to parameters such as engine rotational speed and load, using a map that has been adapted in advance using a standard engine. Considering the existence of engine manufacturing variations and changes over time, the maximum charging efficiency is not always obtained.

  The present invention has been made in view of such circumstances. Therefore, the object of the present invention is to reliably satisfy the demands for cost reduction and downsizing without being affected by variations in manufacturing of internal combustion engines and changes over time. An object of the present invention is to provide a control device for an internal combustion engine capable of improving the charging efficiency.

  In order to achieve the above object, an invention according to claim 1 is directed to an internal combustion engine control apparatus having an air flow meter capable of detecting intake air pulsation of an internal combustion engine, wherein the intake passage is located downstream of the throttle valve of the internal combustion engine. And an intake opening / closing valve for opening / closing the intake passage, and a control means for controlling the opening / closing operation of the intake opening / closing valve so as to reduce the intake pulsation detected from the output of the air flow meter. is there.

  In the intake pulsation region, the present invention is provided on the downstream side of the throttle valve, paying attention to the characteristic that the supercharging effect of the intake by the variable intake device becomes smaller as the transmission of the pulsation upstream of the intake opening / closing valve becomes larger. The opening / closing operation of the intake opening / closing valve is controlled so as to reduce the intake pulsation, whereby the supercharging effect can be maximized and the charging efficiency can be improved. In addition, since intake pulsation is detected from the output of the air flow meter, even if there are manufacturing variations or changes over time of the internal combustion engine, the intake pulsation variation due to the influence is reflected in the control of the opening / closing operation of the intake opening / closing valve to ensure filling. Efficiency can be improved. Furthermore, since it is a relatively simple configuration that only includes an air flow meter that can detect intake pulsation and an intake opening / closing valve, the configuration is simple and the entire device can be downsized compared to conventional variable intake systems. The demand for cost reduction can also be satisfied.

  In this case, as in claim 2, an intake opening / closing valve is provided in the intake manifold upstream of the intake manifold of each cylinder in the intake passage, and the relationship between the intake stroke of each cylinder and the intake pulsation timing is considered. The intake on / off valve is closed during a predetermined period determined by the above [specifically, the period during which the reflection (reverse flow) of the intake pulsation from the intake valve reaches the intake on / off valve], and the intake on / off valve is closed during other periods. It is good to control so that it opens. In this way, if control is performed to close the intake on / off valve during the period in which the intake pulsation reflection (reverse flow) from the intake valve side reaches the intake on / off valve, the intake pulsation reflection is It can be reflected to the intake manifold side of the intake stroke cylinder, and the charging efficiency can be further improved by effectively utilizing the reflection pulsation of the intake pulsation.

  In this case, the closing timing and / or the closing period of the intake opening / closing valve may be feedback controlled so that the intake pulsation detected from the output of the air flow meter is reduced. If it does in this way, filling efficiency can be improved more certainly by feedback control.

  Further, according to a fourth aspect of the invention, there is provided learning means for learning the control data of the control means for each operation region of the internal combustion engine and storing the learned value in a rewritable nonvolatile storage means, and opening and closing of the intake opening / closing valve When starting the operation control, in the operation region learned by the learning means, the control of the opening / closing operation of the intake opening / closing valve may be started using the learning value as an initial value. In this way, in the learned operation region, it is possible to improve the charging efficiency by controlling the closing timing and / or the closing period of the intake opening / closing valve to be close to the optimum value from the beginning of the control of the opening / closing operation of the intake opening / closing valve. it can.

  Further, when a reverse flow of the intake air occurs in the intake passage, the forward flow of the intake air toward the inside of the cylinder is hindered, and the charging efficiency is lowered. In view of this point, in a control device for an internal combustion engine having a variable intake valve device that changes the opening / closing characteristics (valve timing, lift amount, etc.) of the intake valve as in claim 5, An air flow meter capable of detecting back flow and control means for controlling the opening / closing characteristics of the intake valve so as not to generate back flow based on the output of the air flow meter may be provided. In this way, if an air flow meter that can detect backflow is used to control the opening and closing characteristics of the intake valve so that backflow is not detected by the airflow meter, the charging efficiency can be improved even if there are manufacturing variations or changes over time of the internal combustion engine. Therefore, it is possible to reliably prevent the backflow of the intake air, which is a factor that decreases the charging efficiency, and to improve the filling efficiency.

  In this case, as in claim 6, the air flow meter can also detect intake air pulsation of the internal combustion engine, and the intake valve pulsation is increased so that the back flow does not occur based on the output of the air flow meter. The opening / closing characteristics may be controlled. In this way, it is possible to further improve the charging efficiency by effectively using the intake air pulsation while preventing the backflow of the intake air, which causes a decrease in the charging efficiency.

  Further, as claimed in claim 7, there is provided learning means for learning the control data of the control means for each operating region of the internal combustion engine and storing the learned value in a rewritable nonvolatile storage means, and opening and closing the intake valve When starting the control of the characteristics, the control of the opening / closing characteristics of the intake valve may be started with the learning value as an initial value in the operation region learned by the learning means. In this way, in the learned operation region, the charging efficiency can be improved by controlling the opening / closing characteristics of the intake valve to be close to the optimum value from the beginning of the control of the opening / closing characteristics of the intake valve.

  Hereinafter, two Examples 1 and 2, which embody the best mode for carrying out the present invention, will be described.

A first embodiment of the present invention will be described with reference to FIGS.
First, a schematic configuration of the entire engine control system will be described with reference to FIG.
An air cleaner 13 is provided at the most upstream portion of the intake pipe 12 of the engine 11 which is an internal combustion engine, and an air flow meter 14 for detecting the intake air amount is provided downstream of the air cleaner 13. The air flow meter 14 is a highly responsive air flow meter whose output changes with a good response in accordance with a change in the amount of intake air, and can detect intake pulsation and reverse flow. When backflow occurs, the output of the air flow meter 14 becomes a negative value.

  A throttle valve 16 whose opening is adjusted by a motor 15 and a throttle opening sensor 17 that detects the opening (throttle opening) of the throttle valve 16 are provided on the downstream side of the air flow meter 14. As shown in FIGS. 1 and 2, the intake manifold 12a (intake passage) on the downstream side of the throttle valve 16 is provided with an intake opening / closing valve 18 for opening and closing the passage in the intake manifold 12a. The opening / closing operation of the opening / closing valve 18 is driven by an actuator such as a motor 19.

  A surge tank 12b is provided on the downstream side of the intake opening / closing valve 18, and an intake manifold 20 for introducing air into each cylinder of the engine 11 is provided in the surge tank 12b, and an intake port of the intake manifold 20 of each cylinder. A fuel injection valve 21 for injecting fuel is attached in the vicinity. In this case, the length of the intake manifold 20 of each cylinder is the same so that the length of the intake passage from the intake valve 31 of each cylinder to the intake opening / closing valve 18 is the same. An ignition plug 22 is attached to the cylinder head of the engine 11 for each cylinder, and the air-fuel mixture in the cylinder is ignited by spark discharge of each ignition plug 22.

  On the other hand, the exhaust pipe 23 of the engine 11 is provided with an exhaust gas sensor 24 (air-fuel ratio sensor, oxygen sensor, etc.) for detecting the air-fuel ratio or rich / lean of the exhaust gas. A catalyst 25 such as a three-way catalyst for purifying gas is provided.

  A cooling water temperature sensor 26 that detects the cooling water temperature is attached to the cylinder block of the engine 11. A crank angle sensor 28 that outputs a pulse signal every time the crankshaft 27 rotates by a predetermined crank angle is attached to the outer peripheral side of the crankshaft 27 of the engine 11, and the crank angle sensor 28 outputs a crank signal based on the output signal of the crank angle sensor 28. Angles and engine speed are detected.

  Outputs of these various sensors are input to an engine control circuit (hereinafter referred to as “ECU”) 30. The ECU 30 is composed mainly of a microcomputer, and executes each routine (not shown) for engine control stored in a built-in ROM (storage medium), so that the fuel of the fuel injection valve 21 of each cylinder is obtained. The injection amount and the ignition timing of the spark plug 22 are controlled.

  Further, the ECU 30 executes an intake air opening / closing valve intermittent closing control routine of FIGS. 4 and 5 to be described later, thereby opening / closing the intake air opening / closing valve 18 so that the intake pulsation detected from the output of the air flow meter 14 is reduced. Control.

  Here, with reference to FIG. 3 (an example of a four-cylinder engine), the relationship between the intake stroke of each cylinder (# 1 to # 4), the waveform of intake pulsation, the closing timing TVID of the intake opening / closing valve 18 and the closing period will be described. To do. As the intake air pulsation in which the intake air amount increases or decreases in each intake stroke of each cylinder occurs and the intake air pulsation detected by the air flow meter 14 increases, the supercharging effect by the intake on-off valve 18 decreases and the charging efficiency decreases. There is a characteristic to do.

  Accordingly, a reflection period (reverse flow) of the intake pulsation from the intake valve 31 side reaches the intake opening / closing valve 18 for a predetermined period determined in consideration of the relationship between the intake stroke of each cylinder and the intake pulsation timing. “Intermittent closing control” is performed in which the intake on-off valve 18 is closed during the period (a period near the minimum point of the intake pulsation waveform) and the intake on-off valve 18 is opened at other periods. Then, during the execution of the intermittent closing control, feedback control is performed on the closing timing TVID (and / or the closing period) of the intake opening / closing valve 18 so that the intake pulsation detected from the output of the air flow meter 14 is reduced.

  Further, the closing timing TVID of the intake on / off valve 18 is learned for each engine operation region, and the learned value is stored in a memory such as a backup RAM which is a non-volatile storage means that can be rewritten. When starting the closing control, in the learned engine operation region, the learning value is set to the initial value of the closing timing TVID of the intake opening / closing valve 18 and the intermittent closing control of the intake opening / closing valve 18 is started. In this way, in the learned engine operating region, the closing timing TVID of the intake on / off valve 18 can be controlled to be close to the optimum value from the beginning of the intermittent on / off control of the intake on / off valve 18 to improve the charging efficiency.

  The intermittent closing control of the intake on / off valve 18 according to the first embodiment described above is executed by the ECU 30 as follows according to the intake on / off valve intermittent closing control routine of FIGS. 4 and 5. This routine is executed at a predetermined cycle during engine operation, and serves as a control means in the claims. When this routine is started, first, in step 101, input processing for inputting the output of the air flow meter 14, the engine speed, and the engine load (in-cylinder charged air amount, throttle opening, accelerator opening, etc.) is executed.

  Thereafter, the process proceeds to step 102, where it is determined whether or not it is an intake pulsation generation region based on the engine speed and the engine load (cylinder charged air amount, throttle opening, accelerator opening, etc.). In general, intake pulsation tends to occur near the throttle fully open. Note that the intake pulsation width detected from the output of the air flow meter 14 [that is, the difference value between the maximum point (peak point) and the minimum point (bottom point) of the intake pulsation waveform) is greater than or equal to a predetermined value. You may make it determine whether it is a pulsation generation | occurrence | production area | region.

  If it is determined in step 102 that the region is not the intake pulsation occurrence region, this routine is terminated without performing the subsequent processing. On the other hand, if it is determined in step 102 that the region is the intake pulsation generation region, the process proceeds to step 103, and the closing period of the intake on / off valve 18 is calculated from a map or the like according to the engine speed or the like. The closing period of the intake opening / closing valve 18 may be calculated from a map or the like according to the intake pulsation width.

  Thereafter, the process proceeds to step 104, where it is determined whether or not the closing timing TVID of the intake on / off valve 18 in the current engine operation region has been learned. The learning value of the closing timing TVID of the intake opening / closing valve 18 corresponding to the above is read from the memory, and this learning value is set as the initial value of the closing timing TVID of the intake opening / closing valve 18.

  On the other hand, if it is determined in step 104 that the closing timing TVID of the intake on / off valve 18 in the current engine operating region has not been learned, the process proceeds to step 106, and the intake on / off valve is determined in accordance with the engine speed or the like. The initial value of 18 closing timing TVID is calculated by a map or the like. The initial value of the closing timing TVID of the intake opening / closing valve 18 may be calculated from a map or the like according to the intake pulsation width.

  As described above, after the initial value of the closing timing TVID of the intake on-off valve 18 is set in step 105 or 106, the process proceeds to step 107, and the feedback correction amount vidfb of the closing timing TVID is set to a predetermined value KVIDINI. In the next step 108, the intermittent closing control of the intake opening / closing valve 18 is started, the intake opening / closing valve 18 is closed at the initial value of the closing timing TVID of the intake opening / closing valve 18, and the intake air is taken in after the closing period calculated in step 103 has elapsed. The on-off valve 18 is opened. Thereafter, the routine proceeds to step 109, where the intake pulsation width Qw0 is calculated from the difference between the maximum point (peak point) and the minimum point (bottom point) of the intake pulsation waveform.

  Thereafter, the process proceeds to step 110 in FIG. 5, the feedback correction amount vidfb is added to the previous closing timing TVID to obtain the current closing timing TVID, and in the next step 111, the intake opening / closing valve at the current closing timing TVID. 18 is closed, and the intake on-off valve 18 is opened after the closing period has elapsed. Thereafter, the routine proceeds to step 112, where the intake pulsation width Qw is calculated from the difference between the maximum point (peak point) and the minimum point (bottom point) of the intake pulsation waveform.

Thereafter, the process proceeds to step 113, and the intake pulsation width change amount QwDIF is obtained by subtracting the current intake pulsation width Qw from the previous intake pulsation width Qw0.
QwDIF = Qw0-Qw

  When the intake pulsation width change amount QwDIF is a positive value, it means that the intake pulsation width is controlled in a direction in which the intake pulsation width decreases (that is, a direction approaching the closing timing TVID at which the charging efficiency is maximized). When the width change amount QwDIF becomes a negative value, it means that the intake pulsation width is controlled in the direction in which it increases (that is, in the direction away from the closing timing TVID at which the charging efficiency is maximized).

Thereafter, the process proceeds to step 114, and the feedback correction amount vidfb is corrected according to the intake pulsation width change amount QwDIF by adding the value obtained by multiplying the intake pulsation width change amount QwDIF by the feedback gain KVIDGAIN to the feedback correction amount vidfb.
vidfb = vidfb + QwDIF × KVIDGAIN

Thereafter, the routine proceeds to step 115 where the current intake pulsation width Qw is stored as the previous value Qw0 in preparation for the next calculation.
Qw0 = Qw

  Then, in the next step 116, it is determined whether or not the region has shifted to a region where no intake pulsation occurs. If the intake pulsation generation region still continues, the processing of steps 110 to 115 is repeated. As a result, during the period in which the intake pulsation generation region continues, the closing timing TVID of the intake on / off valve 18 is feedback-corrected so that the intake pulsation width becomes small, and the closing timing TVID at which the charging efficiency is maximized is controlled.

  Thereafter, when the intake pulsation ceases to occur, the intermittent closing control of the intake opening / closing valve 18 is terminated, the intake opening / closing valve 18 is opened, and the routine proceeds to step 117 where the final control result of the closing timing TVID of the intake opening / closing valve 18 is reached. Is stored as a learning value in a memory such as a backup RAM. This learned value is learned for each engine operating condition and stored in the memory. The processing in step 117 serves as learning means in the claims.

  According to the first embodiment described above, focusing on the characteristic that the charging efficiency decreases as the intake pulsation increases, the intake opening / closing valve 18 is provided in the collective intake pipe 12a downstream of the throttle valve 16, and the intake pulsation waveform is obtained. In accordance with the timing near the minimum point (near the bottom pressure), intermittent closing control is performed to intermittently close the intake opening / closing valve 18, and intake opening / closing is performed so that the intake pulsation detected from the output of the air flow meter 14 is reduced. Since the closing timing TVID of the valve 18 is feedback-controlled, the charging efficiency can be improved by the intermittent closing control of the intake opening / closing valve 18. During the intermittent closing control, the closing period of the intake opening / closing valve 18 is feedback-controlled so that the intake pulsation detected from the output of the air flow meter 14 is reduced, or both the closing period and the closing timing TVID are feedback-controlled. You may make it do.

  In addition, in the first embodiment, since the intake pulsation is detected from the output of the air flow meter 14, even if there is a manufacturing variation of the engine 11 or a change with time, the intake pulsation variation due to the influence is controlled to intermittently close the intake opening / closing valve 18. It is possible to improve the filling efficiency with certainty. Furthermore, since the air flow meter 14 capable of detecting the intake pulsation and the intake opening / closing valve 18 are relatively simple, the configuration is simple and the entire apparatus can be downsized as compared with the conventional variable intake system. Can meet the demand for cost reduction.

  Further, in the first embodiment, since the intake pulsation reflection (reverse flow) from the intake valve 31 side reaches the intake on / off valve 18, the intake on / off valve 18 is closed. The intake on / off valve 18 can be reflected to the intake manifold 20 side of the other intake stroke cylinders, and the charging efficiency can be effectively improved by effectively utilizing the reflection of the intake pulsation.

  In the intake / closing valve intermittent closing control routine of FIGS. 4 and 5, the closing timing TVID of the intake opening / closing valve 18 is feedback-controlled so that the intake pulsation detected from the output of the air flow meter 14 is reduced. The closing period of the intake opening / closing valve 18 may be feedback-controlled, or both the closing timing TVID and the closing period may be feedback-controlled.

  The second embodiment of the present invention shown in FIGS. 6 and 7 is a system including a variable intake valve timing device 32 (variable intake valve device) that changes the opening / closing timing of the intake valve 31 (hereinafter referred to as “intake VCT”). (The intake opening / closing valve 18 required in the first embodiment is not necessary in the second embodiment). Other system configurations are the same as those in the first embodiment.

  When a reverse flow of the intake air occurs in the intake pipe 12, the forward flow of the intake air toward the cylinder is hindered, and the charging efficiency is lowered. Considering this point, in the second embodiment, the air flow meter 14 capable of detecting the backflow and pulsation of the intake air is used, and the intake VCT is controlled based on the output of the airflow meter 14 so that the backflow does not occur. The target intake VCT is corrected so that the intake pulsation increases within a range where no backflow occurs. In this way, even if there are manufacturing variations or changes over time of the engine 11, the charging efficiency can be effectively utilized by effectively using the intake pulsation while reliably preventing the backflow of the intake air, which causes a decrease in the charging efficiency. Can be improved.

  Further, the target intake VCT correction amount is learned for each engine operation region, and the learned value is stored in a memory such as a backup RAM which is a rewritable non-volatile storage means, and when the intake VCT control is started. In the learned engine operation region, the learning value is set to the initial value of the target intake VCT correction amount, and the intake VCT control is started. In this way, in the learned engine operation region, it is possible to improve the charging efficiency by controlling the intake VCT near the optimum value from the beginning of the control of the intake VCT.

  The control of the intake VCT of the second embodiment described above is executed by the ECU 30 as follows according to the intake VCT control routine of FIG. This routine is executed at a predetermined cycle during engine operation, and serves as a control means in the claims. When this routine is started, first, in step 201, input processing for inputting various sensor outputs for detecting engine operating conditions such as the output of the air flow meter 14, the engine speed, the engine load, and the coolant temperature is executed.

  Thereafter, the process proceeds to step 202, where it is determined whether or not the intake VCT control execution condition is satisfied based on the current engine operating conditions. If the intake VCT control execution condition is not satisfied, the subsequent processing is performed. This routine is terminated.

  On the other hand, if it is determined in step 202 that the intake VCT control execution condition is satisfied, the process proceeds to step 203, and whether or not the target intake VCT correction amount in the current engine operation region has been learned. If the learning has been completed, the process proceeds to step 105, where the learning value of the target intake VCT correction amount corresponding to the current engine operating region is read from the memory, and this learning value is set as the initial value.

  On the other hand, if it is determined in step 203 that the target intake VCT correction amount in the current engine operation region has not been learned, the process proceeds to step 205, where the target intake VCT correction amount is set to an initial value (eg, 0).

  Thereafter, the routine proceeds to step 206, where the intake VCT control is executed, and the drive hydraulic pressure of the variable intake valve timing device 32 is feedback-controlled so that the actual intake VCT coincides with the target intake VCT. Thereafter, the process proceeds to step 207, where it is determined whether a backflow has occurred depending on whether the output of the air flow meter 14 is a negative value. If it is determined that a backflow has occurred, the process proceeds to step 208. Then, the target intake VCT is retarded. At this time, the retard correction amount of the target intake VCT may be a predetermined constant value, or may be set on a map or the like for each engine operating condition.

  On the other hand, if it is determined in step 207 that no reverse flow has occurred, the process proceeds to step 209, where the target intake VCT is advanced and corrected so that the intake pulsation is maximized within the range where no reverse flow occurs. . At this time, the advance correction amount of the target intake VCT may be set on a map or the like for each engine operating condition, or the process of correcting the advance angle of the target intake VCT by a predetermined constant value is repeated, so that the backflow occurs. The advance correction amount of the target intake VCT that maximizes the intake pulsation within a range that does not occur may be searched.

  Thereafter, the process proceeds to step 210, where it is determined whether or not the intake VCT control execution condition is not satisfied. If the intake VCT control execution condition is still satisfied, the processes of steps 206 to 209 are repeated. Thus, the target intake VCT is corrected so that the intake pulsation is maximized within a range where no backflow occurs.

  Thereafter, when the intake VCT control execution condition is not satisfied, “Yes” is determined in step 210, the process proceeds to step 211, and the final target intake VCT correction amount is stored as a learning value in a memory such as a backup RAM. To do. This learned value is learned for each engine operating condition and stored in the memory. The processing in step 211 serves as learning means in the claims.

  According to the second embodiment described above, taking into account the fact that when a reverse flow of the intake air occurs in the intake pipe 12, the forward flow of the intake air toward the cylinder is hindered and the charging efficiency is reduced. Since the intake VCT is controlled so that no backflow occurs based on the output of the air flow meter 14, the backflow of the intake air that causes a reduction in charging efficiency even if there are manufacturing variations or changes over time of the engine 11 Can be reliably prevented, and the filling efficiency can be improved.

  Moreover, in the second embodiment, since the intake VCT is controlled so that the intake pulsation increases within a range where no backflow occurs based on the output of the air flow meter 14, intake air that causes a reduction in charging efficiency In addition, the charging efficiency can be further improved by effectively using the intake air pulsation while preventing the backflow of the air.

  In the second embodiment, the intake VCT is controlled so that no backflow occurs, but other open / close characteristics (lift amount, working angle, etc.) of the intake valve 31 may be controlled.

  In addition, the present invention is not limited to an intake port injection engine, and is also applicable to a direct injection engine and a dual injection engine having both a fuel injection valve for intake port injection and a fuel injection valve for direct injection. Can be implemented.

1 is a schematic configuration diagram of an entire engine control system in Embodiment 1. FIG. It is a figure which shows roughly the structure of the intake system of the engine of Example 1. FIG. 6 is a time chart for explaining the relationship among the intake stroke, the waveform of intake pulsation, the closing timing TVID of the intake opening and closing valve, and the closing period of each cylinder (# 1 to # 4) of the engine of the first embodiment. 6 is a flowchart showing a flow of processing in the first half of an intake on / off valve intermittent closing control routine according to Embodiment 1; 7 is a flowchart showing a flow of processing in the latter half of the intake air opening / closing valve intermittent closing control routine according to the first embodiment. It is a schematic block diagram of the whole engine control system in Example 2. FIG. 6 is a flowchart illustrating a flow of processing of an intake VCT control routine according to a second embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 12 ... Intake pipe, 12a ... Collective intake pipe (intake passage), 12b ... Surge tank, 14 ... Air flow meter, 16 ... Throttle valve, 17 ... Throttle opening sensor, 18 ... Intake opening / closing valve , 19 ... motor, 20 ... intake manifold, 21 ... fuel injection valve, 22 ... spark plug, 23 ... exhaust pipe, 24 ... exhaust gas sensor, 28 ... crank angle sensor, 30 ... ECU (control means, learning means), 31 ... Intake valve, 32 ... Variable intake valve timing device (variable intake valve device)

Claims (7)

An air flow meter capable of detecting intake air pulsation of an internal combustion engine;
An intake opening / closing valve that is provided in an intake passage downstream of the throttle valve of the internal combustion engine and opens and closes the intake passage;
A control device for an internal combustion engine, comprising: control means for controlling an opening / closing operation of the intake opening / closing valve so that an intake pulsation detected from an output of the air flow meter is reduced. The intake opening / closing valve is provided in a collective intake pipe upstream of the intake manifold of each cylinder in the intake passage,
The control means controls to close the intake opening / closing valve in a predetermined period determined in consideration of the relationship between the intake stroke of each cylinder and the intake pulsation timing, and to open the intake opening / closing valve in another period. The control apparatus for an internal combustion engine according to claim 1.   3. The control unit according to claim 1, wherein the control unit performs feedback control of a closing timing and / or a closing period of the intake on / off valve so that an intake pulsation detected from an output of the air flow meter is reduced. Control device for internal combustion engine. Learning means for learning the control data of the control means for each operating region of the internal combustion engine and storing the learning value in a rewritable nonvolatile storage means;
When starting the control of the opening / closing operation of the intake opening / closing valve, the control means starts the control of the opening / closing operation of the intake opening / closing valve with the learning value as an initial value in the operation region learned by the learning means. The control device for an internal combustion engine according to any one of claims 1 to 3. In a control device for an internal combustion engine having a variable intake valve device that changes the opening and closing characteristics of the intake valve,
An air flow meter capable of detecting the backflow of the intake air of the internal combustion engine;
And a control means for controlling the opening / closing characteristics of the intake valve so that no backflow occurs based on the output of the air flow meter. The air flow meter can also detect intake air pulsation of an internal combustion engine,
6. The internal combustion engine according to claim 5, wherein the control means controls the opening / closing characteristics of the intake valve so that intake pulsation increases within a range in which no backflow occurs based on an output of the air flow meter. Control device. Learning means for learning the control data of the control means for each operating region of the internal combustion engine and storing the learning value in a rewritable nonvolatile storage means;
When starting the control of the opening / closing characteristics of the intake valve, the control means starts the control of the opening / closing characteristics of the intake valve using the learning value as an initial value in the operation region learned by the learning means. The control device for an internal combustion engine according to claim 5 or 6, characterized by the above.

Images