JP4650219B2 - Intake control device for internal combustion engine - Google Patents

Description

  The present invention relates to an intake air control device that controls an intake air amount sucked into a cylinder of an internal combustion engine, and more particularly to an internal combustion engine that achieves control of an intake air amount by variable control of valve lift characteristics of an intake valve. The present invention relates to an intake control device.

  In a gasoline engine, the intake air amount is generally controlled by controlling the opening of a throttle valve provided in the intake passage. As is well known, this type of system has a particularly small throttle valve opening. There is a problem that the pumping loss is large at low load. On the other hand, attempts have been made to control the intake air amount without depending on the throttle valve by changing the opening / closing timing of the intake valve and the lift amount. Similarly, it has been proposed to realize a so-called throttle-less configuration in which the intake system is not equipped with a throttle valve.

Patent Document 1 discloses a variable valve mechanism that can be continuously variably controlled by a lift amount and an operating angle of an intake valve and a central angle of the lift previously proposed by the present applicant. According to this type of variable valve mechanism, as described above, it is possible to variably control the amount of air flowing into the cylinder without depending on the opening degree control of the throttle valve, particularly in a region where the load is small. In other words, so-called throttleless operation or operation with a sufficiently large opening of the throttle valve can be realized, and the pumping loss can be greatly reduced.
JP 2001-263105 A

  However, when the intake air amount is controlled by the variable control of the lift characteristic of the intake valve as described above, the required intake valve opening area becomes very small at idling when the intake air amount is small, so that there is a slight variation in the lift characteristic. This greatly affects the amount of intake air. In particular, in a multi-cylinder internal combustion engine, there is a problem in that variation in torque generated in each cylinder and rotational variation occur due to variation in lift characteristics between cylinders.

In one aspect, the present invention includes a variable valve mechanism having a mechanical configuration that has an actuator common to a plurality of cylinders, and that simultaneously and continuously changes the lift characteristics of the intake valves of the plurality of cylinders of the internal combustion engine, In an intake control device for an internal combustion engine that controls a load output from the internal combustion engine by variably controlling the control position of the variable valve mechanism, the target position of the variable valve mechanism that is given to the actuator is determined in a part of the cycle. Specific cylinder lift characteristic changing means for relatively changing the lift characteristics of the intake valves of the specific cylinders in the plurality of cylinders by correcting in the section, and the specific cylinder lift characteristic changing means includes the intake air amount for the specific cylinder The start timing of the partial section for correcting the target position is variably set according to the required correction amount and the current control position of the variable valve mechanism. Further, the correction amount of the target position in the partial section may be variably set according to the intake air amount request correction amount for the specific cylinder and the current control position of the variable valve mechanism.

  In this way, by changing the lift characteristics of the specific cylinder, the intake air amount can be changed only for the cylinder for which the intake air amount is desired to be changed, and variations in the intake air amount among the cylinders can be suppressed.

In another mode , the correction timing of the variable valve mechanism target position is advanced and the correction amount is increased as the current variable valve mechanism position is a position where the reaction force becomes larger.

  That is, in the variable valve mechanism, for example, as the lift amount increases, the reaction force acting on the actuator increases and the response decreases. However, in the above configuration, the response of the variable valve mechanism due to the magnitude of the reaction force decreases. Corrections taking into account the differences can be made, and the required intake air amount correction amount can be realized with certainty.

In still another aspect , the specific cylinder lift characteristic changing unit sets a correction pattern of a variable valve mechanism target position with respect to a required intake air amount correction amount so as to satisfy a predetermined condition.

For example , the above condition is that the intake valve opening timing of a specific cylinder is retarded from a predetermined limit value.

  Thus, by setting the correction pattern of the variable valve mechanism target position so that the intake valve opening timing is always retarded from the predetermined limit value, deterioration of combustion stability can be prevented.

The limit value, For example, determined by the exhaust valve closing timing of the specific cylinder. That is, the correction pattern of the variable valve mechanism target position is set so that the valve overlap is within a range in which the combustion stability can be ensured, so that deterioration of the combustion stability can be prevented.

  According to the present invention, for example, by correcting the control position of the variable valve mechanism for each cycle, the lift characteristics of the intake valves of the specific cylinders among the plurality of cylinders are relatively changed. Variation, and fluctuations in rotation during idling, variations in air-fuel ratio among cylinders, and the like can be suppressed.

  FIG. 1 is a configuration explanatory view showing the system configuration of an intake control device for an internal combustion engine according to the present invention. The internal combustion engine 1 has an intake valve 3 and an exhaust valve 4, and the valve of the intake valve 3 is operated. As a mechanism, the first variable valve mechanism (VEL) 5 capable of continuously expanding / reducing the lift / operation angle of the intake valve 3 and the center angle of the operation angle can be continuously delayed. A second variable valve mechanism (VTC) 6 is provided. The intake passage 7 is provided with a throttle valve 2 whose opening degree is controlled by an actuator such as a motor. Here, the throttle valve 2 is used to generate a slight negative pressure (for example, −50 mmHg) necessary for the treatment of blow-by gas in the intake passage 7, and adjustment of the intake air amount is performed. The lift characteristics of the intake valve 3 are changed by the first and second variable valve mechanisms 5 and 6. More specifically, the opening degree of the throttle valve 2 is controlled so that the suction negative pressure is constant (for example, −50 mmHg) in a predetermined low load side region (first region). And in the high load side region (second region) where the required load exceeds the maximum load that can be realized by changing the lift characteristic while generating this constant negative pressure, it is fixed to the lift characteristic at the point that becomes the limit, As the load, for example, the accelerator opening APO increases, the opening of the throttle valve 2 further increases. That is, the intake air amount is adjusted by changing the lift characteristic of the intake valve 3 while maintaining a relatively weak intake negative pressure up to a certain load, and in the high load side region close to the fully open region, the intake negative pressure is adjusted. The amount of intake air is adjusted by reducing.

  The first and second variable valve mechanisms 5 and 6 and the throttle valve 2 are controlled by the control unit 10.

  Further, a fuel injection valve 8 is disposed in the intake passage 7, and an amount of fuel corresponding to the intake air amount adjusted by the intake valve 3 or the throttle valve 2 as described above is injected from the fuel injection valve 8. The Therefore, the output of the internal combustion engine 1 is controlled by adjusting the amount of intake air by the first and second variable valve mechanisms 5 and 6 in the first region, and is sucked by the throttle valve 2 in the second region. It is controlled by adjusting the amount of air.

  The control unit 10 includes an accelerator opening signal APO from an accelerator angle sensor 11 provided on an accelerator pedal operated by a driver, an engine speed signal Ne from an engine speed sensor 12, and an intake air amount sensor. The intake air amount signal from 13 is received, and based on these signals, the fuel injection amount, the ignition timing, the first variable valve mechanism target angle, and the second variable valve mechanism target angle are calculated. Then, the fuel injection valve 8 and the spark plug 9 are controlled so as to realize the required fuel injection amount and ignition timing, and the first variable valve mechanism target angle and the second variable valve mechanism target angle are realized. Control signals are output to the actuator of the first variable valve mechanism 5 and the actuator of the second variable valve mechanism 6, respectively.

  Here, the mechanical configuration of the first variable valve mechanism 5 and the second variable valve mechanism 6 is well known, and for example, has the same configuration as the device described in Patent Document 1 described above. . Therefore, although the detailed description thereof is omitted, the first variable valve mechanism 5 is configured to change the rotation position of the control shaft common to the plurality of cylinders by an actuator made of an electric motor, whereby the intake valves 3 of the plurality of cylinders. Since the intake valve 3 is pushed open against the valve spring reaction force, the higher the lift / operating angle, the more the actuator acts on the actuator. The reaction force is large.

  In the present embodiment, the first variable valve mechanism for changing the lift / operating angle and the second variable valve mechanism for changing the central angle are provided. However, the present invention has one variable valve mechanism. Even in this case, the present invention can be similarly applied, and various types of variable valve mechanisms can be used.

  FIG. 2 is a flowchart schematically showing the contents of the control of the present invention, in particular, the process of calculating the target value of the first variable valve mechanism 5 during idling. In this embodiment, the first variable valve mechanism 5 (that is, one actuator) that variably controls the lift and operating angle of the intake valves 3 of a plurality of cylinders at the same time is set at the idle target position, that is, the idle basic target position. By adding a rotation-synchronized correction pulse, the lift / operating angle of a specific cylinder is changed with respect to other cylinders so that the intake air amounts of all the cylinders are made uniform.

  First, the basic target position at the time of idling of the first variable valve mechanism is calculated from the target idle engine speed or the like (step 01). Then, for example, the engine speed variation between the cylinders is detected, and from this, the intake air amount deviation of each cylinder is calculated (step 02). Next, for example, an intake valve opening timing limit value that becomes a combustion stability limit is calculated from the relationship with the exhaust valve closing timing (step 03), and the corrected intake valve opening timing is advanced from this intake valve opening timing limit value. The first variable valve mechanism correction pulse for each cylinder is calculated so as not to be on the side (step 04). The final first variable valve mechanism target position is calculated by adding the correction pulse calculated in step 04 to the first variable valve mechanism idle basic target position at a timing corresponding to each cylinder (step 05).

  FIG. 3 shows the contents of the control of this embodiment as a functional block diagram. The target internal combustion engine is an in-line four-cylinder engine, and the lift and operating angles of the intake valves 3 of all the cylinders are variably controlled by one first variable valve mechanism 5 (that is, one actuator). . In the following description, “#n” means a cylinder number, and n = 1 to 4.

  In FIG. 3, tNE is the target idle engine speed, tQ is the target intake air amount, and NE is the actual engine speed. Based on these, in the first variable valve mechanism idle basic target position calculation unit 101 The first variable valve mechanism common idling basic target position tVEL0 common to all cylinders is calculated. Then, based on the target idle engine speed tNE and the engine speed NE for each cylinder, the intake air amount deviation ΔQ # n of each cylinder is calculated in each cylinder intake air amount deviation calculation unit 102. Note that the engine speed NE can be obtained for each cylinder by paying attention to the engine speed in a minute section in the expansion stroke of each cylinder.

  Further, based on the target intake air amount tQ, the engine speed NE, and the exhaust valve closing timing EVC, the intake valve opening timing limit value calculation unit 103 calculates an intake valve opening timing limit value IVOLIMIT. In this embodiment, the intake valve opening timing limit value IVOLIMIT is common to all cylinders. Based on the first variable valve mechanism idling basic target position tVEL0, the intake valve opening timing limit value IVOLIMIT, the compression TDC signal TDCCOMP # n of each cylinder, and the intake air amount deviation ΔQ # n for each cylinder, In each first variable valve mechanism correction pulse #n calculation unit 111 to 114, the first variable valve mechanism correction pulse PULSE # n of each cylinder is calculated. A first variable valve mechanism correction pulse PULSE, which is obtained by adding the first variable valve mechanism correction pulses PULSE # n (n = 1 to 4) of these cylinders at the addition point 104, is added at the addition point 105. The first variable valve mechanism target position tVEL is calculated by adding to the variable valve mechanism idle basic target position tVEL0. The actuator of the first variable valve mechanism 5 is controlled toward the first variable valve mechanism target position tVEL, whereby the lift characteristic of the intake valve 3 is changed for each cylinder individually with one actuator. .

  FIG. 4 shows details of the first variable valve mechanism correction pulse #n computing units 111 to 114 of a cylinder (#n cylinder) in the functional block diagram shown in FIG. As shown in the figure, the timing correction amount HOS_Tn is calculated by multiplying the intake air amount deviation ΔQ # n of the #n cylinder by the timing gain GAIN_T indicated by reference numeral 201, and this is sequentially added to the previous value as indicated by reference numeral 202. Further, the basic correction pulse timing T_PULSE0n is calculated by subtracting the absolute value as indicated by reference numeral 203 from the correction pulse timing initial value T0_PULSE output from the correction pulse timing initial value calculation unit 204.

  Also, the height correction amount HOS_Hn is calculated by multiplying the intake air amount deviation ΔQ # n of the #n cylinder by the height gain GAIN_H output from the height gain calculation unit 205, and this is sequentially changed as indicated by reference numeral 206. In addition to the previous value, the correction pulse height H_PULSEn is calculated. Similarly, the width correction amount HOS_Wn is calculated by multiplying the intake air amount deviation ΔQ # n of the #n cylinder by the width gain GAIN_W output from the width gain calculation unit 207, and this is sequentially changed to its previous value as indicated by reference numeral 208. In addition, the correction pulse width W_PULSEn is calculated as an absolute value as indicated by reference numeral 209.

  Based on the basic correction pulse timing T_PULSE0n, the correction pulse height H_PULSEn, and the correction pulse width W_PULSEn calculated as described above, the intake valve opening timing estimation unit 210 estimates the intake valve opening timing IVO # n. Then, this is compared with the intake valve opening timing limit value IVOLIMIT by the comparison unit 211. If IVO # n ≧ IVOLIMIT (the intake valve opening timing is retarded from the intake valve opening timing limit value), the selection unit 212 is selected. The basic correction pulse timing T_PULSE0n is set as the correction pulse timing T_PULSEn. Otherwise, the previous correction pulse timing value is set as the correction pulse timing T_PULSEn (that is, the correction pulse timing is not advanced).

  Next, on the basis of the compression top dead center signal TDCCOMP # n, the correction pulse timing T_PULSEn, the correction pulse height H_PULSEn, and the correction pulse width W_PULSEn, the correction pulse #n waveform generation unit 213 corrects the #n cylinder correction pulse PULSE #. n is calculated.

  Here, the correction pulse timing initial value T0_PULSE, the height gain GAIN_H, and the width gain GAIN_W are each calculated by table search based on the first variable valve mechanism idle basic target position tVEL0 described above. That is, the correction pulse timing initial value T0_PULSE is calculated by the correction pulse timing initial value calculation unit 204 using the correction pulse timing initial value calculation table shown in FIG. 5A, and the height gain GAIN_H is calculated by the height gain calculation. 5 is calculated using the height gain calculation table shown in FIG. 5B, and the width gain GAIN_W is calculated using the width gain calculation table shown in FIG. The In the present embodiment, these are calculated only from the first variable valve mechanism idle basic target position tVEL0. However, it may be changed depending on the engine speed, including the timing gain GAIN_T.

  FIG. 6 is a time chart showing details of the correction pulse #n waveform generation unit 213 in the block diagram shown in FIG. 4, and shows changes in (a) compression top dead center signal and (b) correction pulse. Yes. With reference to the compression top dead center signal TDCCOMP # n of the #n cylinder indicated by reference numeral A1 in (a), the correction pulse for the #n cylinder indicated by reference numeral B4 in (b) is output. , (B) are output so that the magnitudes indicated by the symbols B1, B2, and B3 are the correction pulse timing T_PULSen, the correction pulse height H_PULSEn, and the correction pulse width W_PULSen calculated in FIG. 4, respectively. Here, the magnitude indicated by the symbol B0 in (b) is the correction pulse timing initial value T0_PULSE.

  Next, FIG. 7 is a time chart showing the operation in the steady state during idling according to this embodiment. As an example, this represents a correction state when the intake valve lift of the # 1 cylinder varies and the intake air amount of the # 1 cylinder is smaller than the intake air amount of the other cylinders (# 2 to # 4). (A) a predetermined cycle average of the engine speed NE in the expansion stroke of each cylinder, (b) a correction pulse timing T_PULSE for each cylinder, (c) a correction pulse height H_PULSE for each cylinder, and (d) a correction for each cylinder. A change in the pulse width W_PULSE is shown.

  The solid line indicated by the symbol A1 in (a) indicates the change in the predetermined cycle average of the engine speed (that is, the engine speed of the # 1 cylinder) during the expansion stroke of the # 1 cylinder. Similarly, the solid lines of A2, A3, and A4 are , Respectively show predetermined cycle averages of engine speeds in the expansion strokes of the # 2, # 3, and # 4 cylinders (that is, engine speeds of the # 2 to # 4 cylinders). In the example of this figure, since correction is applied only to the # 1 cylinder, its rotational speed changes. On the other hand, the # 2 to # 4 cylinders are not corrected, so the rotational speed is constant. Also, the dotted line with the symbol A5 in (a) represents the target engine speed, and the dotted line with A6 and the dotted line with A7 represent the allowable range, that is, the upper limit rotational speed and the lower limit rotational speed that are normally determined as variations. Then, the first variable valve mechanism target position correction is started from time t1. Here, the time of the predetermined cycle is t2-t1 (= t3-t2).

  The engine speed of the # 1 cylinder up to the time t1 is a value indicated by reference numeral A11 in (a) and is lower than the lower limit rotational speed that is normal determination of fluctuation indicated by reference numeral A7 in (a). Is done. Accordingly, the intake air amount deviation ΔQ # 1 (target engine speed ≧ # 1 cylinder) corresponding to the deviation from the target engine speed indicated by reference numeral A5 in (a) (indicated by reference numeral A01 in (a)). The first variable valve mechanism correction pulse pattern of the # 1 cylinder (correction) according to the target engine speed <the engine speed of the # 1 cylinder, and negative when the engine speed is Pulse timing T_PULSE # 1, correction pulse height H_PULSE # 1, correction pulse width W_PULSE # 1) are calculated. In other words, at time t1, the correction pulse timing of the # 1 cylinder is changed from the initial value of the correction pulse timing indicated by the sign B0 in (b) to the value indicated by the sign B11 in (b). The correction pulse height and the correction pulse width are values indicated by a reference C11 in (c) and values indicated by a reference D11 in (d), respectively. As a result, the engine speed of the # 1 cylinder in a predetermined cycle period (time t1 to t2) from time t1 becomes a value indicated by reference numeral A12 in (a). However, since the engine speed indicated by reference sign A12 is still below the lower limit speed indicated by reference sign A7 in (a), it is determined again that there is a variation, and the deviation from the target engine speed indicated by reference sign A5 in (a). The correction pulse timing T_PULSE # 1, the correction pulse height H_PULSE # 1, the correction pulse width W_PULSE # 1, in accordance with the intake air amount deviation ΔQ # 1 of the # 1 cylinder corresponding to (indicated by reference numeral A02 in (a)) Is calculated. These are the values indicated by the symbol B12 in (b), the values indicated by the symbol C12 in (c), and the values indicated by the symbol D12 in (d). As a result, the engine speed of the # 1 cylinder in a predetermined cycle period (time t2 to t3) from time t2 becomes a value indicated by reference symbol A13 in (a), and a lower limit for determining normality of variation indicated by reference symbol A7 in (a). Since the rotational speed is exceeded, the variation is determined to be within the normal range, and the first variable valve mechanism correction pulse pattern for the # 1 cylinder is not changed after time t3.

  In this way, the correction pulse timing T_PULSE # 1, the correction pulse height H_PULSE # 1, and the correction pulse width W_PULSE # 1 of the # 1 cylinder are indicated by the solid line indicated by the reference symbol B1 in (b) and the reference symbol C1 in (c), respectively. The solid line changes as shown by the solid line indicated by D1 in FIG. On the other hand, the engine speeds of cylinders # 2 to # 4 are within the range between the upper limit value and the lower limit value for which variation is normally determined. Therefore, correction is not performed, and correction pulse timings T_PULSE # 2 to 4 for each cylinder are corrected. The pulse height H_PULSE # 2 to 4 and the correction pulse width W_PULSE # 2 to 4 are respectively a solid line indicated by a symbol B2 in (b), a solid line indicated by a symbol C2 in (c), and a solid line indicated by a symbol D2 in (d). Thus, it becomes a constant value.

  FIG. 8 is an arrangement of the time chart of FIG. 7 by the crank angle for each cycle from the compression top dead center of the # 1 cylinder. (A) First variable valve mechanism position VEL, (b) Intake valve lift The change in the amount, (c) in-cylinder pressure in motoring is shown. The horizontal axis is the crank angle, and the crank angles indicated by reference signs D1, D2, D3, D4, and D5 are the compression top dead center, bottom dead center, top dead center, bottom dead center, and compression top dead center of the cylinder # 1, respectively. The periods indicated by reference signs D6, D7, D8, and D9 are the expansion stroke, the exhaust stroke, the intake stroke, and the compression stroke of the # 1 cylinder, respectively.

  Before the time t1 of FIG. 7 is before the first variable valve mechanism target position correction is performed, the first variable valve mechanism target position is the first variable valve mechanism idle basic target position indicated by reference numeral A0 in FIG. The lift curves of the intake valves of the # 1 to # 4 cylinders are lines indicated by reference numerals B10, B2, B3, and B4 in (b), respectively. Further, the cylinder pressures during the motoring of the # 1 to # 4 cylinders are solid lines indicated by reference numerals C10, C2, C3, and C4 of (c), respectively. At this time, the lift / operating angle is smaller than the lift curve of the other cylinders by the lift curve of the # 1 cylinder due to variations, and the in-cylinder pressure (maximum in-cylinder pressure) at the compression top dead center of the # 1 cylinder is It is smaller than the maximum in-cylinder pressure by the amount indicated by the reference C01 in (c). That is, the intake air amount of the # 1 cylinder is relatively small. Note that the difference in intake air amount between the # 2 and # 3 cylinders is small, and is not shown in the figure.

  7, since the first variable valve mechanism correction pattern for the # 1 cylinder is calculated as shown in FIG. 7, the first variable valve mechanism target position tVEL is represented by the symbol (a). The first variable valve mechanism actual position is changed as indicated by a solid line indicated by reference numeral A21 in FIG. As a result, the lift curve of the # 1 cylinder changes as indicated by the solid line B11 in (b), and the in-cylinder pressure of the # 1 cylinder becomes as indicated by the solid line indicated by C11 in (c). Accordingly, the intake air amount of the # 1 cylinder is improved, but the maximum in-cylinder pressure of the # 1 cylinder is still smaller than the maximum in-cylinder pressure of the other cylinders by the amount indicated by the reference C02 in (c).

  At time t2 to t3 in FIG. 7, the first variable valve mechanism correction pattern for the # 1 cylinder is calculated as shown in FIG. 7, and the first variable valve mechanism target position tVEL is represented by reference numeral A12 in FIG. The first variable valve mechanism actual position is changed as indicated by a solid line indicated by reference numeral A22 in FIG. As a result, the lift curve of the # 1 cylinder changes as indicated by the solid line B12 in (b), and the in-cylinder pressure of the # 1 cylinder becomes as indicated by the solid line indicated by the reference C12 in (c). The intake air amount is improved and the variation among cylinders is eliminated.

  In this embodiment, the intake air amount deviation of each cylinder is determined according to the deviation of the engine speed of each cylinder from the target engine speed. In the example of FIG. 7, the average value of the engine speeds of # 2 to # 4 cylinders may be used. Further, when a sensor capable of detecting the in-cylinder pressure of each cylinder is provided, the intake air amount deviation may be estimated from the in-cylinder pressure of each cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS Configuration explanatory drawing which shows the system configuration | structure of the intake control device of the internal combustion engine which concerns on this invention. The flowchart which shows the target value calculation process of the 1st variable valve mechanism at the time of idling. The functional block diagram of this control. The functional block diagram which shows the detail of the 1st variable valve mechanism correction pulse #n calculating part. The characteristic view which shows the characteristic (a) of a correction pulse timing initial value, the characteristic (b) of a height gain, and the characteristic (c) of a width gain. The time chart which shows the example of the waveform of a 1st variable valve mechanism correction pulse. The time chart which shows the effect | action of a present Example at the time of idling. The time chart which arrange | positions the effect | action of the correction | amendment of a present Example in order by a crank angle.

Explanation of symbols

2 ... Throttle valve 5 ... First variable valve mechanism 6 ... Second variable valve mechanism 10 ... Control unit 11 ... Accelerator opening sensor

Claims (8)

A variable valve mechanism with a mechanical structure that has an actuator common to multiple cylinders and changes the lift characteristics of the intake valves of the multiple cylinders of the internal combustion engine simultaneously and continuously, and the control position of this variable valve mechanism In an intake control device for an internal combustion engine that controls a load output from the internal combustion engine by variably controlling,
Specific cylinder lift characteristic changing means for relatively changing the lift characteristic of an intake valve of a specific cylinder in a plurality of cylinders by correcting a target position of the variable valve mechanism given to the actuator in a partial section in the cycle Have
The specific cylinder lift characteristic changing means can vary the start timing of the partial section for correcting the target position in accordance with the intake air amount request correction amount for the specific cylinder and the current control position of the variable valve mechanism. An intake air control apparatus for an internal combustion engine, wherein the intake air control apparatus is set. Further, the correction amount of the target position in the partial section is variably set according to the intake air amount request correction amount for the specific cylinder and the current control position of the variable valve mechanism. Item 2. An intake control device for an internal combustion engine according to Item 1. A variable valve mechanism that changes the lift characteristics of the intake valves of multiple cylinders of an internal combustion engine simultaneously and continuously. This variable valve mechanism is a reaction force caused by a valve spring reaction force on an actuator that is common to multiple cylinders. In the intake air control device for an internal combustion engine that controls the load output from the internal combustion engine by variably controlling the control position of the variable valve mechanism,
Specific cylinder lift characteristic changing means for relatively changing the lift characteristic of the intake valve of the specific cylinder among the plurality of cylinders;
The specific cylinder lift characteristic changing means determines the correction timing and correction amount of the variable valve mechanism target position according to the intake air amount request correction amount for the specific cylinder and the current variable valve mechanism position,
The current of the variable valve mechanism position, as is the position where the reaction force becomes large, as well as faster correction timing of the variable valve mechanism target position, the inner combustion engine you characterized by increasing the amount of correction Intake control device. An internal combustion engine that includes a variable valve mechanism that simultaneously and continuously changes lift characteristics of intake valves of a plurality of cylinders of an internal combustion engine, and that controls a load output from the internal combustion engine by variably controlling a control position of the variable valve mechanism. In the intake control device of the engine,
Specific cylinder lift characteristic changing means for relatively changing the lift characteristic of the intake valve of the specific cylinder among the plurality of cylinders;
The specific cylinder lift characteristic changing means, so as to satisfy a predetermined condition, the intake control device of the internal combustion engine you and sets the correction pattern of the variable valve mechanism target position relative to the intake air amount required correction amount. 5. The intake control apparatus for an internal combustion engine according to claim 4 , wherein the intake valve opening timing of the specific cylinder is on the retard side of a predetermined limit value. 6. The intake control apparatus for an internal combustion engine according to claim 5 , wherein the limit value is determined by an exhaust valve closing timing of the specific cylinder. The said specific cylinder lift characteristic change means changes the lift characteristic of a specific cylinder by correct | amending the control position of the said variable valve mechanism for every cycle, The change characteristic of any one of Claims 1-6 characterized by the above-mentioned. An intake control device for an internal combustion engine.   8. The variable valve mechanism according to any one of claims 1 to 7, wherein the lift / operating angle of the intake valve continuously increases or decreases in accordance with a control position of an electric actuator common to a plurality of cylinders. An intake control device for an internal combustion engine according to claim 1.

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