JP2009085143A - Engine intake air amount control device - Google Patents

Abstract

An engine intake air amount control apparatus capable of controlling the intake air amount of an engine with high accuracy even when the lift characteristic of the intake valve during idle operation changes and the amount of blow-by gas changes.
A pressure and an atmospheric pressure in an intake pipe downstream of a throttle valve are detected, a blow-by gas amount is estimated from the pressure and the atmospheric pressure in the intake pipe, and a target throttle opening based on a target intake air amount is set to the blow-by gas. Correction is made based on the amount, and the throttle actuator is controlled based on the corrected target throttle opening.
[Selection] Figure 7

Description

  The present invention relates to an engine intake air amount control device including a blow-by gas reduction device that introduces blow-by gas into an intake pipe downstream of a throttle valve, and an electronically controlled throttle device that opens and closes the throttle valve by a throttle actuator.

In Patent Document 1, when the intake air amount during idle operation is predicted, the amount of air leaked when the throttle is fully closed as the fixed air amount is added to the amount of air passing through the idle control valve according to the opening of the idle control valve. It is disclosed that the amount of blow-by gas is added.
JP-A-10-159633

As described above, in Patent Document 1, the blow-by gas amount during idle operation is a fixed value. However, in an engine having a variable valve mechanism that makes the lift characteristics of the intake valve variable, the valve lift amount and the valve Due to the change in timing, the intake pipe negative pressure may change even during the same idling operation, which may cause the blow-by gas amount to change.
For this reason, if the blow-by gas amount during idle operation is treated as a fixed value as in the prior art, the control accuracy of the intake air amount during idle operation decreases, and the engine rotation speed during idle operation becomes unstable. There was a problem.

  The present invention has been made in view of the above problems, and can control the intake air amount of the engine with high accuracy even if the lift characteristics of the intake valve during idle operation change and the amount of blow-by gas changes. An object of the present invention is to provide an intake air amount control device for an engine.

Therefore, in the first aspect of the invention, the pressure and atmospheric pressure in the intake pipe downstream of the throttle valve are detected, the blow-by gas amount is estimated from the pressure and atmospheric pressure in the intake pipe, and the target throttle opening based on the target intake air amount is estimated. The degree is corrected based on the blow-by gas amount, and the throttle actuator is controlled based on the corrected target throttle opening.
According to the above invention, for example, the variable valve mechanism that makes the lift characteristic of the intake valve variable is provided, and when the intake pipe internal pressure changes in accordance with the change of the lift characteristic, the amount of blow-by gas according to the actual intake pipe internal pressure Therefore, even if the intake pipe pressure changes, the amount of blow-by gas can be correctly estimated, and the intake air amount can be controlled with high accuracy in anticipation of the amount of blow-by gas.

According to the second aspect of the present invention, the opening area of the blowby gas control valve provided in the blowby gas supply passage communicating from the crank chamber of the engine into the intake pipe is estimated as a value corresponding to the amount of blowby gas.
According to the above invention, since the opening area of the control valve for controlling the blow-by gas amount is estimated as a value corresponding to the blow-by gas amount, the throttle actuator is controlled by obtaining the required opening area for obtaining the required intake air amount. Further, it is possible to easily correct the opening area based on the estimation result of the blow-by gas amount.

In the invention of claim 3, the opening area of the blow-by gas control valve is subtracted from the target throttle opening area corresponding to the target intake air amount, and the opening area of the subtraction result is converted into the target throttle opening degree. .
According to the above invention, the opening area of the blow-by gas control valve as a value corresponding to the blow-by gas amount is subtracted from the target throttle opening area corresponding to the target intake air amount, so that the throttle valve of the target intake air amount is reduced. A throttle opening area corresponding to the passage amount is obtained, and the target intake air amount is obtained as a sum of the reduction amount of blowby gas and the air amount passing through the throttle valve by controlling the throttle valve to an opening degree corresponding to the opening area. be able to.

Embodiments of the present invention will be described below.
FIG. 1 is a system configuration diagram of a vehicle engine in the embodiment.
In FIG. 1, an electronic control throttle device 104 that opens and closes a throttle valve 103 b by a throttle motor 103 a (throttle actuator) is interposed in an intake pipe 102 of an engine (gasoline spark ignition internal combustion engine) 101. In addition, air is sucked into the combustion chamber 106 through the intake valve 105.

Further, an electromagnetic fuel injection valve 131 is provided in the intake port 130 upstream of the intake valve 105 of each cylinder.
The fuel injection valve 131 is supplied with fuel adjusted to a predetermined pressure, and an intake valve supplies an amount of fuel (gasoline) proportional to the injection pulse width (opening time) of the injection pulse signal sent from the engine control unit 114. It injects toward 105.

The air-fuel mixture in the combustion chamber 106 is ignited and burned by spark ignition by a spark plug (not shown).
The fuel injection valve 131 may be an in-cylinder direct injection engine that directly injects fuel into the combustion chamber 106 or a compression self-ignition engine.
The combustion exhaust in the combustion chamber 106 is discharged through an exhaust valve 107, purified by the front catalytic converter 108 and the rear catalytic converter 109, and then released into the atmosphere.

The exhaust valve 107 is driven to open and close by a cam 111 provided on the exhaust camshaft 110 while maintaining a constant valve lift, valve operating angle, and valve timing.
On the other hand, the lift characteristic of the intake valve 105 is made variable by a variable lift mechanism 112 and a variable valve timing mechanism 113 as a variable valve mechanism. The variable lift mechanism 112 sets the valve lift amount of the intake valve 105 together with the valve operating angle. It is a mechanism that continuously varies, and when the valve lift amount is increased (decreased), the valve operating angle is also increased (decreased) at the same time.

The variable valve timing mechanism 113 is a mechanism that continuously changes the central phase of the valve operating angle of the intake valve 105 by changing the rotational phase of the intake valve drive shaft 3 with respect to the crankshaft 120.
The engine control unit 114 incorporating the microcomputer sets the fuel injection amount (injection pulse width), the ignition timing, the target intake air amount, the target intake pipe negative pressure by arithmetic processing according to a program stored in advance. Based on these, a control signal is output to the fuel injection valve 131, a power transistor for the ignition coil (not shown), the electronic control throttle device 104, the variable lift mechanism 112, and the variable valve timing mechanism 113.

A unit for controlling the fuel injection amount and ignition timing of the engine 101 and a unit for controlling the lift characteristics of the intake valve 105 by the variable lift mechanism 112 and the variable valve timing mechanism 113 can be provided separately.
Detection signals from various sensors are input to the engine control unit 114.

  The various sensors are supported by an air flow meter 115 for detecting the intake air amount of the engine 101, an accelerator pedal sensor 116 for detecting the depression amount (accelerator opening) of an accelerator pedal operated by a vehicle driver, and a crankshaft 120. By detecting a detected portion provided on the signal plate, a crank angle sensor 117 that outputs a unit crank angle signal POS for each unit crank angle, a throttle sensor 118 that detects an opening TVO of the throttle valve 103b, and an engine 101 A water temperature sensor 119 for detecting the coolant temperature, and a detected portion provided on a signal plate supported by the intake valve drive shaft 3 described later, thereby detecting a cam signal for each reference rotational position of the intake valve drive shaft 3. Cam sensor 132 for outputting, atmospheric pressure sensor 13 for detecting atmospheric pressure (Atmospheric pressure detecting means), and the like are provided a pressure sensor 136 for detecting an intake pipe pressure downstream of the throttle valve 103b (internal pressure detecting means).

  The unit crank angle signal POS is set in advance so as to cause tooth loss at every crank angle (180 ° CA for four cylinders) corresponding to the stroke phase difference between the cylinders of the engine 101, and the unit crank angle signal POS. Is detected based on the output cycle of the unit crank angle signal POS, so that the reference crank angle position REF for each stroke phase difference can be detected.

Further, the rotational speed NE of the engine 101 is detected based on the detection interval time of the reference crank angle position REF, and the crank angle sensor 117 constitutes detection means for detecting the engine rotational speed NE.
The crank angle sensor 117 generates a reference crank angle signal for each crank angle corresponding to the stroke phase difference, measures the interval time at which the reference crank angle signal is generated, and determines the engine speed NE from the interval time. Various known methods can be applied to the detection signal characteristics of the crank angle sensor 117 and the calculation method of the engine rotational speed NE.

FIG. 2 is a perspective view showing the structure of the variable lift mechanism 112.
In the engine 101 of this embodiment, a pair of intake valves 105 is provided for each cylinder, and an intake valve drive shaft 3 that is rotationally driven by the crankshaft 120 is arranged in the cylinder row direction above the intake valves 105. It is supported so that it can rotate along.
A swing cam 4 that contacts the valve lifter 105a of the intake valve 105 and opens and closes the intake valve 105 is fitted on the intake valve drive shaft 3 so as to be relatively rotatable.

A variable lift mechanism 112 for continuously changing the operating angle and valve lift amount of the intake valve 105 is provided between the intake valve drive shaft 3 and the swing cam 4.
In FIG. 2, the variable lift mechanism 112 is shown only on one side of the pair of intake valves 105, and the other side is not shown.
A variable valve timing mechanism that continuously changes the center phase of the operating angle of the intake valve 105 by changing the rotational phase of the intake valve drive shaft 3 with respect to the crankshaft 120 at one end of the intake valve drive shaft 3. 113 is arranged.

  As shown in FIGS. 2 and 3, the variable lift mechanism 112 includes a circular drive cam 11 that is eccentrically fixed to the intake valve drive shaft 3 and a ring that is externally fitted to the drive cam 11 so as to be relatively rotatable. A link 12, a control shaft 13 that extends substantially parallel to the intake valve drive shaft 3 in the cylinder row direction, a circular control cam 14 that is eccentrically fixed to the control shaft 13, and a relative position to the control cam 14. A rocker arm 15 that is rotatably fitted and has one end connected to the tip of the ring-shaped link 12, and a rod-shaped link 16 connected to the other end of the rocker arm 15 and the swing cam 4. Yes.

The control shaft 13 is rotationally driven by a motor 17 via a gear train 18, and a preset minimum lift position / minimum is set by a stopper 13 a provided integrally with the control shaft 13 coming into contact with the fixed side. Further rotation to the lift / working angle decrease side is restricted at an angular position corresponding to the working angle position (hereinafter simply referred to as the minimum lift position).
With the above configuration, when the intake valve drive shaft 3 rotates in conjunction with the crankshaft 120, the ring-shaped link 12 moves substantially in translation through the drive cam 11, and the rocker arm 15 swings around the axis of the control cam 14. The swing cam 4 swings through the rod-shaped link 16 and the intake valve 105 is driven to open and close.

Further, by driving and controlling the motor 17 to change the rotation angle of the control shaft 13, the axial center position of the control cam 14 serving as the rocking center of the rocker arm 15 changes and the posture of the rocking cam 4 changes. .
As a result, the operating angle of the intake valve 105 and the valve lift amount continuously change while the central phase of the operating angle of the intake valve 105 remains substantially constant.

A detection signal from an angle sensor 133 that detects the rotation angle of the control shaft 13 is input to the engine control unit 114, and the angle of the engine control unit 114 is set to rotate the control shaft 13 to a target angle position corresponding to a target lift amount. Based on the detection result of the sensor 133, the direction and magnitude of the current of the motor 17 are feedback-controlled.
Next, the configuration of the variable valve timing mechanism 113 will be described with reference to FIG.

  The variable valve timing mechanism 113 in this embodiment is a vane type variable valve timing mechanism, and is a cam sprocket 51 (timing sprocket) that is rotationally driven by a crankshaft 120 via a timing chain, and an end of the intake valve drive shaft 3. A rotating member 53 that is fixed to the camshaft and rotatably accommodated in the cam sprocket 51, a hydraulic circuit 54 that rotates the rotating member 53 relative to the cam sprocket 51, the cam sprocket 51, and the rotating member 53 And a lock mechanism 60 that selectively locks the relative rotational position of the two at a predetermined position.

The cam sprocket 51 includes a rotating part (not shown) having a tooth part meshed with a timing chain (or timing belt) on the outer periphery, and a housing that is disposed in front of the rotating part and rotatably accommodates the rotating member 53. 56, and a front cover and a rear cover (not shown) for closing the front and rear openings of the housing 56.
The housing 56 has a cylindrical shape with openings at the front and rear ends, and has a trapezoidal shape in cross section on the inner peripheral surface, and four partition walls 63 provided along the axial direction of the housing 56 are spaced by 90 °. It is projecting at.

The rotating member 53 is fixed to the front end portion of the intake valve drive shaft 3, and four vanes 78 a, 78 b, 78 c, 78 d are provided on the outer peripheral surface of the annular base 77 at 90 ° intervals.
Each of the first to fourth vanes 78a to 78d has a substantially inverted trapezoidal cross section, and is disposed in a recess between the partition walls 63. The recesses are separated from each other in the rotational direction, and the vanes 78a to 78d. An advance side hydraulic chamber 82 and a retard side hydraulic chamber 83 are formed between both sides and both side surfaces of each partition wall 63.

The lock mechanism 60 is configured such that the lock pin 84 engages with an engagement hole (not shown) at the rotation position (reference operation state) on the maximum retard angle side of the rotation member 53.
The hydraulic circuit 54 includes two systems, a first hydraulic passage 91 that supplies and discharges hydraulic pressure to the advance side hydraulic chamber 82 and a second hydraulic passage 92 that supplies and discharges hydraulic pressure to the retard side hydraulic chamber 83. These hydraulic passages 91 and 92 are connected to a supply passage 93 and drain passages 94a and 94b through passage switching electromagnetic switching valves 95, respectively.

The supply passage 93 is provided with an engine-driven oil pump 97 that pumps oil in the oil pan 96, while the downstream ends of the drain passages 94 a and 94 b communicate with the oil pan 96.
The first hydraulic passage 91 is connected to four branch passages 91 d that are formed substantially radially in the base 77 of the rotating member 53 and communicate with the advance-side hydraulic chambers 82. It is connected to four oil holes 92 d that open to the retard side hydraulic chamber 83.

The electromagnetic switching valve 95 is configured such that an internal spool valve body relatively switches and controls the hydraulic passages 91 and 92, the supply passage 93, and the drain passages 94a and 94b.
The engine control unit 114 controls the energization amount to the electromagnetic actuator 99 that drives the electromagnetic switching valve 95 based on a duty control signal.
For example, when a control signal (OFF signal) with a duty ratio of 0% is output to the electromagnetic actuator 99, the hydraulic oil pressure-fed from the oil pump 47 is supplied to the retard-side hydraulic chamber 83 through the second hydraulic passage 92. At the same time, the hydraulic oil in the advance side hydraulic chamber 82 is discharged from the first drain passage 94 a into the oil pan 96 through the first hydraulic passage 91.

Therefore, the internal pressure of the retard side hydraulic chamber 83 is high and the internal pressure of the advance side hydraulic chamber 82 is low, and the rotating member 53 rotates to the maximum retard side via the vanes 78a to 78b. The opening period (opening timing and closing timing) of the intake valve 105 is delayed.
On the other hand, when a control signal (ON signal) with a duty ratio of 100% is output to the electromagnetic actuator 99, the hydraulic oil is supplied into the advance side hydraulic chamber 82 through the first hydraulic passage 91 and the retard side hydraulic pressure is supplied. The hydraulic oil in the chamber 83 is discharged to the oil pan 96 through the second hydraulic passage 92 and the second drain passage 94b, and the retard side hydraulic chamber 83 becomes low pressure.

For this reason, the rotating member 53 rotates to the maximum advance side via the vanes 78a to 78d, and thereby the opening period (opening timing and closing timing) of the intake valve 105 is advanced.
The configuration of the variable valve mechanism is not limited to the variable lift mechanism 112 and the variable valve timing mechanism 113 configured as described above.
Further, the engine 101 is provided with a closed type blow-by gas reduction device 141 shown in FIG.

The blow-by gas reduction device 141 introduces the blow-by gas in the crankcase 142 into the engine 101 via the rocker cover 143, the blow-by gas control valve 144, and the blow-by gas supply passage 145 that reaches the intake pipe downstream of the throttle valve 103b. It is a system to let you.
The blow-by gas control valve 144 has a valve and a spring incorporated in the valve body, and the position of the valve in the valve body changes in the upstream and downstream directions due to the spring load and the differential pressure across the valve. Is used to variably control the passage flow rate, that is, the amount of blow-by gas to be reduced.

Next, control of the electronic control throttle device 104, the variable lift mechanism 112, and the variable valve timing mechanism 113 by the engine control unit 114 (configuration of the intake air amount control device according to the present application) will be described in detail.
FIG. 6 shows calculation processing of the control target value (target lift amount) TGVEL of the variable lift mechanism 112 and the control target value (target advance amount) TGVTC of the variable valve timing mechanism 113 by the engine control unit 114.

The engine control unit 114 feedback-controls the variable lift mechanism 112 based on the control target value (target lift amount) TGVEL, and the variable valve timing mechanism 113 based on the control target value (target advance amount) TGVTC. Feedback control.
In FIG. 6, the engine rotational speed NE and the target volume flow rate ratio TQH0ST (target intake air amount) are input to the TGVEL calculator 301 and the TGVTC calculator 302, respectively.

The engine speed NE is a value calculated based on a detection signal from the crank angle sensor 117.
Further, the target volume flow ratio TQH0ST is calculated by dividing the required air amount Q obtained based on the accelerator opening APO and the engine rotational speed NE by the engine rotational speed NE and the effective exhaust amount (total cylinder volume) VOL #. (TQH0ST = Q / (Ne · VOL #)).

The TGVEL calculation unit 301 calculates a control target value TGVEL that increases the lift amount of the intake valve 105 as the target volume flow ratio TQH0ST is larger and the engine speed NE is higher.
The TGVTC calculation unit 302 calculates a control target value TGVTC such that the center phase of the valve operating angle of the intake valve 105 is retarded as the target volume flow ratio TQH0ST is larger and the engine speed NE is higher.

FIG. 7 shows a calculation process of the target throttle opening degree TGTVO by the engine control unit 114.
In FIG. 7, the first conversion unit 401 converts the target volume flow rate ratio TQH0ST into a state quantity AANV0 using a conversion table as shown in the figure.
The state quantity AANV0 is data represented by AANV0 = At / (Ne · VOL #), where the throttle valve opening area is At, the engine speed is NE, and the displacement (cylinder volume) is VOL #. .

Next, in the first multiplier 402 and the second multiplier 403, the state quantity AANV0 is multiplied by the engine speed NE and the exhaust amount VOL #, respectively, so that the state quantity AANV0 is converted into the basic throttle opening area TVOAA0. Is done.
The basic throttle opening area TVOAA0 is a throttle opening area required when the lift characteristic (valve lift / valve timing) of the intake valve 105 is the reference characteristic.

The third multiplication unit 404 multiplies the basic throttle opening area TV0AA0 by a correction value KAVEL to perform correction according to the actual operating characteristic of the intake valve 105.
The correction value KAVEL is set in order to ensure a constant amount of air even if the operating characteristic of the intake valve 105 changes, and is specifically calculated as follows.
First, in the reference pressure ratio calculation unit 410, the ratio (Pm0 / Pa) between the target manifold pressure Pm0 and the atmospheric pressure Pa when the lift characteristic of the intake valve 105 is the reference characteristic is set as the target volume flow ratio TQH0ST and the engine. Obtained based on the rotational speed NE.

Then, in the KPA0 calculation unit 411, based on the pressure ratio (Pm0 / Pa), the table TBLKPA0 shown in the figure is searched to calculate the coefficient KPA0.
On the other hand, the target pressure ratio setting unit 412 sets the target pressure ratio (Pm1 / Pa) when the variable lift mechanism 112 is controlled to the control target value TGVEL based on the target volume flow ratio TQH0ST and the engine speed NE. To do.

Then, the KPA1 calculation unit 413 searches the table TBLKPA1 shown in the figure based on the pressure ratio (Pm1 / Pa) to calculate the coefficient KPA1.
The division unit 414 divides the KPA 0 by KPA 1 to calculate a correction value KAVEL (KAVEL = KPA 0 / KPA 1), and outputs this to the third multiplication unit 404.
The throttle opening area TVOAA0 corrected with the correction value KAVEL in the third multiplication unit 404 is output to the first subtraction unit 415, where the opening area PCVAA corresponding to the blow-by gas amount is subtracted, and the result is the final value. Is output as a throttle opening area TVOAA (TVOAA = TVOAA0−PCVAA) (correction means).

The opening area PCVAA is calculated as follows.
First, the second subtraction unit 416 receives the atmospheric pressure detected by the atmospheric pressure sensor 135 and the intake pipe internal pressure downstream of the throttle valve 103b detected by the pressure sensor 136, and calculates the atmospheric pressure and the intake pipe internal pressure. The differential pressure (actual intake manifold negative pressure) is calculated.
The differential pressure (actual intake manifold negative pressure) calculated by the second subtracting unit 416 is output to the PCVAA calculating unit 417, and a table TBLPCVV shown in the figure is searched based on the differential pressure to calculate the opening area PCVAA. Calculate (estimating means).

  The differential pressure calculated by the second subtraction unit 416 corresponds to the differential pressure across the blow-by gas control valve 144, and the opening area of the blow-by gas control valve 144 changes according to the differential pressure before and after that. The correlation between the differential pressure and the opening area of the blow-by gas control valve 144 is stored in the table TBLPCVV in advance, and the opening area PCVAA is obtained from the differential pressure at that time.

The intake air amount of the engine 101 is the sum of the amount of air passing through the throttle valve 103b and the amount of air passing through the blow-by gas control valve 144, and the amount of air introduced into the cylinder from the target intake air amount via the blow-by gas control valve 144 The amount of air obtained by subtracting the minute may be introduced into the cylinder via the throttle valve 103b.
This indicates that the opening area obtained by subtracting the opening area of the blow-by gas control valve 144 from the opening area TVOAA0 for obtaining the target intake air amount becomes the opening area required for the throttle valve 103b.

The ratio of the opening area of the blow-by gas control valve 144 to the opening area TVOAA0 for obtaining the target intake air amount increases as the engine 101 operates at a low load, and as the engine 101 operates at a low load, the blow-by gas control valve 144 increases. If correction for the opening area is not performed, the cylinder intake air amount becomes larger than the target.
Furthermore, when the variable lift mechanism 112 and the variable valve timing mechanism 113 are provided and the lift characteristic of the intake valve 105 is variably controlled as in this embodiment, the lift characteristic can be improved even during the same idling operation. Depending on the difference, the differential pressure across the blow-by gas control valve 144 may differ, and the opening area of the blow-by gas control valve 144 may differ, and the opening area (passage air amount) of the blow-by gas control valve 144 is constant. If considered, high-precision correction cannot be performed.

  Therefore, in this embodiment, the atmospheric pressure and the intake pipe internal pressure are detected by the sensors, respectively, and the differential pressure across the blow-by gas control valve 144 at that time is detected. Therefore, the lift characteristics of the intake valve 105 are different. The opening area TVOAA0 can be corrected based on the actual opening area PCVAA of the blowby gas control valve 144, even if the opening area PCVAA differs, and thus the target intake air amount can be accurately adjusted. You can control it.

  When the throttle opening area TVOAA is obtained as described above, the second conversion unit 405 converts the throttle opening area TVOAA to the target throttle opening degree TGTVO of the throttle valve 103b using a conversion table as shown in the figure. The electronic control throttle device 104 (throttle actuator) is feedback-controlled based on the target throttle opening degree TGTVO (control means).

  Note that the correction of the throttle opening area TVOAA by the opening area PCVAA of the blow-by gas control valve 144 is more effective when the load is low, and the presence or absence of the correction greatly increases the operability (intake air amount) of the engine 101 during high load operation. Since there is no influence, the correction of the throttle opening area TVOAA by the opening area PCVAA can be performed only during idle operation, for example.

Further, the pressure in the intake pipe detected by the pressure sensor 136 when the engine 101 is stopped or when the throttle valve is fully opened can be regarded as the atmospheric pressure. In this case, the atmospheric pressure sensor 135 can be omitted, and the pressure sensor 136 serves as both the tube pressure detection means and the atmospheric pressure detection means.
Further, the blow-by gas control valve 144 passing air amount can be subtracted from the target intake air amount, and the target throttle opening area or the target throttle opening degree can be determined from the subtraction result.

Here, technical ideas other than the claims that can be grasped from the above embodiment will be described together with effects.
(B) The engine intake air amount control device according to any one of claims 1 to 3, wherein the engine includes a variable valve mechanism that makes a lift characteristic of the intake valve variable.
According to the above invention, even if the intake valve internal pressure changes due to the lift characteristics of the intake valve being changed by the variable valve mechanism, and the amount of air passing through the blow-by gas control valve changes, it matches the actual amount of air passing through. The target throttle opening can be determined by applying the correction.
(B) As the variable valve mechanism, a variable lift mechanism that continuously changes the valve lift amount of the intake valve together with the valve operating angle, and a variable valve timing that continuously changes the center phase of the valve operating angle of the intake valve. The engine intake air amount control device according to claim 1, further comprising a mechanism.

According to the above invention, even if the intake pipe internal pressure is changed by changing the valve lift amount, the valve operating angle, and the center phase of the valve operating angle of the intake valve, and the air passing through the blow-by gas control valve is changed, The target throttle opening degree can be determined by applying a correction corresponding to the amount of air passing through.
(C) While the variable lift mechanism and the variable valve timing mechanism are controlled based on the target intake air amount, the blowby gas amount is changed from the target throttle opening area set based on the target intake air amount and the target intake pipe negative pressure. The engine intake air amount control device according to claim (2), wherein an opening area of a corresponding blowby gas control valve is subtracted, and the electronic control throttle device is controlled based on the opening area after the subtraction.

  According to the above invention, it is possible to accurately control the target intake air amount by accurately estimating the passing air amount of the blow-by gas control valve while controlling the target intake pipe negative pressure.

The system diagram of the engine for vehicles in an embodiment. The perspective view which shows the detail of the variable lift mechanism in embodiment. Sectional drawing which shows the operating angle change mechanism of the said variable lift mechanism. Sectional drawing which shows the detail of the variable valve timing mechanism in embodiment. The figure which shows the blow-by gas reduction apparatus in embodiment. The block diagram which shows the calculation process of the target valve lift amount and target valve timing in embodiment. The block diagram which shows the calculation process of the target throttle opening in embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Intake valve drive shaft, 13 ... Control shaft, 17 ... Motor, 101 ... Engine, 103a ... Throttle motor (throttle actuator) 103b ... Throttle valve, 104 ... Electronically controlled throttle device, 105 ... Intake valve, 112 ... Variable lift mechanism 113 ... Variable valve timing mechanism, 114 ... Engine control unit, 116 ... Accelerator pedal sensor, 117 ... Crank angle sensor, 120 ... Crankshaft, 132 ... Cam sensor, 133 ... Angle sensor, 135 ... Atmospheric pressure sensor (atmospheric pressure detecting means) ) 136... Pressure sensor (pipe internal pressure detecting means) 141... Blow-by gas reducing device 142... Crank case 143... Rocker cover 144 144 Blow-by gas control valve 145.

Claims (3)

An intake air amount control device for an engine, comprising: a blow-by gas reduction device for introducing blow-by gas into an intake pipe downstream of the throttle valve; and an electronically controlled throttle device for opening and closing the throttle valve by a throttle actuator,
In-pipe pressure detection means for detecting the pressure in the intake pipe downstream of the throttle valve;
Atmospheric pressure detection means for detecting atmospheric pressure;
Estimating means for estimating the amount of blow-by gas from the pressure in the intake pipe and atmospheric pressure;
Correction means for correcting the target throttle opening based on the target intake air amount based on the blow-by gas amount;
Control means for controlling the throttle actuator based on the target throttle opening corrected by the correction means;
An intake air amount control device for an engine characterized by comprising:   The estimation means estimates an opening area of a blow-by gas control valve provided in a blow-by gas supply passage communicating from the crank chamber of the engine into the intake pipe as a value corresponding to the amount of the blow-by gas. 2. An intake air amount control device for an engine according to 1.   The correction means subtracts the opening area of the blow-by gas control valve from the target throttle opening area corresponding to the target intake air amount, and converts the opening area of the subtraction result into a target throttle opening degree. Item 3. The intake air amount control device for an engine according to Item 2.

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