JP5233480B2 - Intake control device for internal combustion engine - Google Patents

Description

  The present invention relates to an intake control device for an engine, and more particularly to an improvement in response of throttle valve opening control.

  As a control of the intake air amount of the engine, there is known a variable valve mechanism that variably controls the operation characteristics (valve timing, lift amount) of the intake valve, thereby controlling the intake air amount. According to this, it is possible to eliminate the throttle loss at the throttle valve, which has conventionally controlled the intake air amount, and to improve fuel consumption.

  However, there is a case where intake negative pressure is required to suck purge gas and blow-by gas into the intake system or as a negative pressure source for brake master back. Therefore, a throttle valve is provided, and the throttle valve is controlled so as to generate an intake negative pressure under a predetermined condition. Further, in the low load range, the lift amount of the intake valve is reduced and it becomes difficult to control the air amount by the intake valve, so the control is switched to the control by the throttle valve.

  As an example of such intake air amount control, Patent Document 1 discloses a throttle valve control device that performs control so that a target intake air amount is obtained with a target response.

Specifically, it has means for calculating the reference response time constant, and sets the target throttle opening based on the target intake pressure, virtual intake pressure, reference response time constant, and virtual cylinder intake amount (intake air amount). ing. Here, the time constant is uniquely determined according to the operating state.
JP 2007-278083 A

  By the way, in general, it is considered that the drivability is better when the response characteristics are high with respect to the driver's accelerator operation. On the other hand, when changing the intake air amount in response to load fluctuations that do not involve accelerator operation, such as when the air conditioner switch is turned on and off, torque fluctuations become abrupt when high response is made, giving the driver a sense of incongruity It becomes a factor.

  Thus, the required responsiveness may differ even under the same operating conditions (engine speed and load).

  However, the control device disclosed in Patent Document 1 has a problem that it cannot meet different responsiveness requirements because the time constant is uniquely determined according to the operating state.

  Therefore, an object of the present invention is to enable setting of time constants according to different responsiveness requests as described above.

The intake control apparatus for an internal combustion engine according to the present invention includes an acceleration time reference response time constant calculating means for calculating an acceleration time reference response time constant, and a non-acceleration time reference response time calculating non-acceleration time reference response time constant. Constant calculation means, the presence or absence of the driver's intention to accelerate, the presence or absence of a request to reduce the responsiveness of the norm response time constant, the means for calculating the target intake pressure, and the virtual intake equivalent to the current intake pressure Select the driving state detection means to detect the deviation between the target intake pressure and the virtual intake pressure based on the calculation result of the means for calculating the atmospheric pressure, and select the norm response time constant for acceleration when there is intention to accelerate, and When there is no target, a reference response time constant switching determination unit that selects a reference response time constant for non-acceleration time, and a target throttle opening that is calculated using the reference response time constant selected by the reference response time constant switching determination unit Throttle opening calculation means With a nominal response time constant switching determining means, as a virtual intake pressure based on the deviation between the target intake pressure and the virtual intake pressure is determined whether the converged to the target intake pressure, the acceleration intention is present until convergence And

  According to the present invention, since the target throttle opening is calculated using the reference response time constant according to the driving state, it corresponds to both a situation where high responsiveness is required and a situation where low responsiveness is required. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram of a system configuration of the first embodiment, and is a cross-sectional view of the periphery of an engine cylinder as viewed from the front side of the engine.

  2 is a cylinder head, 3 is a cylinder block, 4 is a piston that slides in a cylinder provided in the cylinder block 3, 1 is a combustion chamber formed by the lower surface of the cylinder head 2, the cylinder block 3, and the crown surface of the piston 4, 5 Is an intake passage, 6 is an exhaust passage, 7 is an intake valve, 8 is an exhaust valve, 9 is a variable valve mechanism for driving the intake valve 7, 10 is an exhaust camshaft, 11 is a fuel injection valve, 12 is a spark plug, 13 Is a control unit (target throttle opening calculating means, acceleration standard response time constant calculating means, non-acceleration standard response time constant calculating means, operating state detecting means, reference response time constant switching determining means, target intake pressure calculating means , Virtual intake pressure calculating means), 14 is a throttle valve.

  The intake passage 5 and the exhaust passage 6 each have an opening in the combustion chamber 1, the intake valve 7 opens and closes the opening of the intake passage 5, and the exhaust valve 8 opens and closes the opening of the exhaust passage 6. The intake valve 7 and the exhaust valve 8 are driven by a variable valve mechanism 9 and an exhaust camshaft 10, respectively.

  The present embodiment is a so-called intake / exhaust two-valve type in which two intake valves 7 and two exhaust valves 8 are provided in each cylinder, and two intake passages 5 and six exhaust passages 6 are provided in each cylinder. The two intake passages 5 are obtained by branching a passage having one opening on one side surface of the cylinder head 2 inside the cylinder head 2. Further, the two exhaust passages 6 merge inside the cylinder head 2 and have one opening on the other side surface of the cylinder head 2.

  The first fuel injection valve 11 is provided so as to inject fuel directly into the combustion chamber 1 from the side surface of the combustion chamber 1.

  The spark plug 12 is provided near the center of the ceiling surface of the combustion chamber 1. The control unit 13 controls the injection timing, the injection amount, the injection pressure, etc. of the first fuel injection valve 11 and the ignition timing of the spark plug 12, and also serves as an intermediate load in-cylinder gas flow strengthening means, which will be described later as an intermediate load lift region. In order to strengthen the in-cylinder gas flow at the cylinder.

  The throttle valve 14 is basically fully open, and the intake air amount is adjusted by controlling the valve timing, lift amount, and operating angle of the intake valve 7, which will be described later. However, when a negative pressure for brake master back (not shown) is required, the opening degree is decreased in order to generate a negative pressure in the intake passage 5 in a predetermined case. In addition, you may make it respond | correspond to the case where the said negative pressure is required by providing the pump for negative pressure generation, without providing the throttle valve 14. FIG.

  Further, since the exhaust camshaft 10 is a general rotary camshaft, description of the drive mechanism and the like is omitted. On the other hand, the variable valve mechanism 9 is a variable valve mechanism that can variably control the lift amount and operating angle of the intake valve 7, and is disclosed in a known variable valve mechanism (for example, Japanese Patent Application Laid-Open No. 2007-278083). Can be applied).

  FIG. 2 is a main block diagram of intake air amount control by the throttle valve 14 executed by the control unit 13.

  The target intake pressure calculation unit B31 calculates a target intake pressure for realizing the target cylinder intake amount in the current cylinder effective volume. Based on the target opening area of the throttle valve 14, the virtual intake pressure calculation unit B39 calculates a virtual intake pressure that is an estimated value of the current intake pressure (manifold internal pressure) using an internal model of the intake system. This virtual intake pressure is input not only to the intake pressure deviation calculation unit B32 but also to the virtual cylinder intake amount calculation unit.

  The intake pressure deviation calculation unit B32 calculates the deviation between the target intake pressure and the virtual intake pressure, and the calculation result is input to the calculation unit B33.

  The calculation unit B33 calculates the target intake pressure change amount based on the deviation between the target intake pressure and the virtual intake pressure and the norm response time constant τPm. The calculation result is converted into a target intake air amount change amount (mass change amount) by the mass conversion unit B34.

  The adding unit B35 adds the virtual cylinder intake air amount calculated by the virtual cylinder intake air amount calculating unit B40 to the dead time compensation unit B41 and the calculation result of the mass conversion unit B34. A target intake air amount per time passing through the throttle valve 14 is calculated.

  The target opening area calculation unit B36 calculates the target opening area of the throttle valve 14 based on this target intake air amount. The actuator response delay compensation unit B37 performs delay compensation processing on the target opening area converted into the target throttle valve opening, and controls the opening of the throttle valve 14 using this as the target throttle opening. The target throttle opening is also input to the virtual intake pressure calculation unit B39.

  The cylinder effective volume calculation unit B38 calculates the cylinder effective volume based on the operating state and the valve timing, and inputs this to the target intake pressure calculation unit B31 and the virtual cylinder intake amount calculation unit B40.

  Next, details of each block will be described.

  In the cylinder effective volume calculation unit B38, as described above, the cylinder effective volume is calculated based on the operating state and the valve timing. The cylinder effective volume is the stroke volume which is the value obtained by subtracting the cylinder volume at the top dead center TDC from the cylinder volume at the intake valve closing timing IVC statically, but actually, the intake stroke start timing and end timing are In this case, deviation occurs with respect to the top dead center TDC and the intake valve closing timing IVC.

  This is because the cylinder internal pressure reaches the intake pressure before the intake valve closing timing IVC. The advance amount of the timing at which the actual intake stroke ends with respect to the intake valve closing timing IVC increases as the engine rotational speed is higher and as the valve lift amount is smaller, the influence of inertia increases.

  Therefore, first, the maximum lift amount is calculated from the valve characteristics of the intake valve 7. Then, a map using the advance amount as the IVC offset amount and the engine speed and the valve lift amount as parameters is set, the IVC offset amount IVCOFS is obtained with reference to this map, and the IVC offset amount is calculated from the intake valve closing timing IVC. The crank angle position obtained by subtracting IVCOFS is calculated as the effective IVC at which the intake stroke ends.

  On the other hand, the deviation from the intake top dead center TDC at the time when the intake stroke starts is caused by exhaust blowback due to valve overlap.

  That is, after the intake valve 7 is opened in the valve overlap state, the cylinder internal pressure gradually decreases from the exhaust pressure, becomes equal to the intake pressure after the intake top dead center TDC, and the intake stroke is started from this point. Since the opening area is small in the vicinity of the start of the intake valve opening, the decrease in the cylinder internal pressure is small, and the substantial decrease starts from the vicinity of the overlap center angle O / LCA where the exhaust blow-back flow rate becomes maximum. The amount of delay from when the cylinder internal pressure begins to decrease to when the actual intake stroke starts (effective TDC) increases as the engine speed increases and as the valve overlap amount (overlap opening area) decreases. The effect increases, and the degree of decrease in the cylinder internal pressure increases.

  Therefore, first, the intake valve opening timing IVO and the intake valve closing timing IVC are input, and the overlap center angle O / LCA is calculated. Specifically, the lift amounts of both characteristics coincide based on the valve characteristic IV of the intake valve 7 determined by the intake valve opening timing IVO and the intake valve closing timing IVC and the known valve characteristic EV of the exhaust valve 8. The crank angle at the point (intersection) to be calculated is calculated as the overlap center angle O / LCA.

  Next, the overlap opening area O / LA with respect to the overlap center angle O / LCA is calculated with reference to a preset map. The smaller the overlap center angle O / LCA is (when it is on the advance side), the larger the overlap opening area O / LA is.

  Next, a map in which the delay amount from the overlap center angle O / LCA to the effective TDC is set as a TDC offset amount using the engine speed and the overlap opening area O / LA as parameters is set, and this map is referred to. A TDC offset amount TDCOFS is obtained, and a crank angle position obtained by adding the TDC offset amount TDCOFS to the overlap center angle O / LCA is calculated as an effective TDC.

  Then, the intake valve opening timing IVO, the intake valve closing timing IVC, and the effective TDC are input, and the cylinder volume VETDC at the effective TDC is calculated from the valve characteristics of the intake valve 7 with reference to the map. The effective IVC is input, and the cylinder volume VEIVC at the effective IVC is calculated with reference to the map.

  The cylinder effective volume VE is calculated by subtracting the cylinder volume VETDC from the cylinder volume VEIVC thus calculated.

  Next, the virtual intake pressure calculation unit B39 and the virtual cylinder intake amount calculation unit B40 will be described.

3, in the real opening area A _TVO subjected to compensation processing delay to the target opening area, which is an example of a model for calculating the air intake passage pressure P _M. Using this model, a virtual value is calculated as a predicted value when the target value is controlled. Hereinafter, the virtual value will be described with “′” added to the actual value.

  In block B51, the target opening area tATVO of the throttle valve 14 calculated by the target opening area calculation unit B36 is subjected to processing for compensating for the delay from the throttle valve 14 to the cylinder by the actuator response delay compensation unit B37. After that, the virtual intake air amount QA ′ is calculated by the following equation (transfer function K1).

Ｐ_A：大気圧
Ｐ_M：マニホールド内圧＝吸気圧
ｔＡ_TVOH：一次遅れ補正後の目標開口面積
Ｒ：ガス定数
Ｔ_A：大気温度＝吸気温度
κ：比熱比
目標開口面積に基づいて算出された、スロットルバルブ１４を通過して吸気通路５に流入する時間当たりの吸気流量Ｑ_A’と、後述するように算出された吸気通路５からの流出量、つまり筒内への時間当たりの流入量Ｑ_E’との偏差（Ｑ_A’−Ｑ_E’）を算出する。

P _A : Atmospheric pressure P _M : Manifold internal pressure = Intake pressure tA _TVOH : Target opening area after primary delay correction R: Gas constant T _A : Atmospheric temperature = Intake temperature κ: Specific heat ratio Calculated based on the target opening area, The intake flow rate Q _A ′ per time passing through the throttle valve 14 and flowing into the intake passage 5 and the outflow amount from the intake passage 5 calculated as described later, that is, the inflow amount Q _E per time into the cylinder Deviation ("Q _A '-Q _E ')" is calculated.

Next, in block B52, the intake air amount deviation is converted into an intake pressure change amount (ΔP _M / Δt) ′ (transfer function: K2).

(ΔP _M / Δt) ′ = RT _A / V _M · (Q _A ′ −Q _E ′) (2)
V _M : Manifold volume In block B 53, the intake pressure change amount (ΔP _M / Δt) ′ is integrated to calculate a virtual intake pressure P _M ′ (transfer function: 1 / s). The above blocks B51 to B53 are the contents of the virtual intake pressure calculation unit B39.

Next, in block B54, based on the virtual intake pressure P _M ′ and the cylinder effective volume VE, a virtual cylinder intake amount Q _C per cylinder is calculated by the following equation (transfer function: K3).

Q _C '= P _M ' · VE / (RT _A ) (3)
In block B55, the virtual cylinder intake air amount Q _C is converted into a flow rate Q _E per time according to the following equation (transfer function: K4).

QE '= QC' · n _cyl / 2 · Ne / 60 (4)
n _cyl : total number of cylinders of the engine Ne: engine rotation speed The virtual cylinder intake air amount Q _E ′ per time is used for calculating a deviation from the intake air amount Q _A ′ calculated next time as described above. This is used for calculating the target intake air amount tQ _A to be performed. The block B54 and the block B55 are the contents of the virtual cylinder intake amount calculation unit.

Here, the virtual intake pressure P _M ′ is obtained by calculation as described above, but it may be detected directly using a pressure sensor.

  Next, the target intake pressure calculation unit B31 will be described.

Target intake pressure calculation unit B31 is the following equation to calculate the target intake pressure tP _M for realizing the target cylinder intake air quantity tQ _C in the current effective cylinder volume VE. Here, the target cylinder intake air amount is an intake air amount necessary for realizing the target torque calculated based on the accelerator opening, the engine speed, and the like.

tP _M = tQ _C · RT _A / VE (5)
Next, the target opening area calculation unit B36 will be described.

Here, based on the target intake air amount tQ _A , the target opening area tATVO of the throttle valve 14 is calculated by the following equation (transfer function: 1 / K).

次に、演算部Ｂ３３の規範応答時定数τＰ_mの設定方法について説明する。

Next, a method for setting the normative response time constant τP _m of the calculation unit B33 will be described.

FIG. 4 is a diagram showing a configuration for calculating the normative response time constant τP _m . As shown in the figure, the engine speed Ne and the load T are input to both of the acceleration-time norm response time constant calculation unit B61 and the non-acceleration-time norm response time constant calculation unit B62. The acceleration response norm response time constant calculation unit B61 calculates an acceleration response norm response time constant based on an acceleration response norm response time constant map, which will be described later. Similarly, the non-acceleration normal response time constant calculation unit B62 calculates the non-acceleration normal response time constant based on the non-acceleration normal response time constant map.

  As shown in FIG. 5, all the norm response time constant maps basically have characteristics that become smaller as the load becomes higher and the rotation speed becomes higher, that is, the response becomes higher. However, comparing acceleration and non-acceleration, the acceleration is set to have a higher response at the same rotation speed and load.

  These acceleration standard response time constants and non-acceleration standard response time constants are input to the switch unit B64. In addition, a switching signal from a switching determination unit B63, which will be described later, is input to the switch unit B64, and either one of the normative response time constants is selected according to this.

  The switching determination unit B63 will be described.

  FIG. 6 is a configuration diagram of the switching determination unit B63. A is an acceleration intention detection calculation unit, B is an intake pressure deviation determination unit, C is an abrupt deceleration stall avoidance determination unit, D is an auxiliary machine load fluctuation determination unit, and E is an idling state determination unit.

  First, the acceleration intention detection unit A that detects the presence or absence of the driver's intention to accelerate will be described.

  AND when the amount of change in accelerator opening, that is, the difference between the current value of the accelerator opening detected by an accelerator opening sensor (not shown) and the previous value (current value−previous value) is greater than or equal to a predetermined value # 1 A trigger is input to one input terminal of the gate 71. Further, when the idle switch is OFF, that is, when the accelerator pedal is depressed, a trigger is input to the other input terminal of the AND gate 71.

  By providing the trigger for the idle switch as described above, it is possible to prevent erroneous determination that there is an intention to accelerate, for example, when there is no intention to accelerate, for example, when the foot is lightly placed on the accelerator pedal while the vehicle is stopped. For this reason, when setting the predetermined value # 1, it is not necessary to consider the prevention of the erroneous determination. Therefore, for example, the predetermined value # 1 is set to determine that there is an intention to accelerate even with a slight change in the accelerator opening. Can be set to zero.

  When the deviation between the target intake pressure and the virtual intake pressure is equal to or greater than a predetermined value # 2 set in advance, a trigger is input to one input terminal of the AND gate 72. Further, the previous value of the acceleration intention detection flag described later is input to the other input terminal.

  The determination unit that determines whether or not the deviation of the intake pressure is equal to or greater than the predetermined value # 2 is for determining whether or not the intake pressure has converged to the target intake pressure. This is intended to improve drivability by setting a time constant for acceleration (high response) until the driver can assume that the target torque has been reached if the driver intends to accelerate. .

  Therefore, based on the intake pressure control accuracy, a value that can reliably determine whether or not the intake pressure has converged to the target intake pressure is set as the predetermined value # 2. More specifically, the intake pressure overshoot amount during transition and the intake pressure fluctuation range during steady state are obtained in advance through experiments or the like, and are set with a safety margin added thereto.

  When the trigger of the AND gate 71 or the AND gate 72 is input to the OR gate 73, an acceleration intention detection flag is set.

  In the acceleration intention detection unit A configured as described above, when the driver depresses the accelerator pedal for the purpose of acceleration, a trigger is input from the AND gate 71 to the OR gate 73, and an acceleration intention detection flag is output from the OR gate 73. . Since this acceleration intention detection flag is input to the AND gate 72, even if the accelerator opening becomes constant with the accelerator pedal depressed, the AND gate 72 continues to the OR gate until the intake pressure converges to the target intake pressure. The trigger continues to be input at 73. Therefore, until the intake pressure converges to the target intake pressure, it is determined that there is an intention to accelerate, and this is input to one input terminal of the OR gate 83.

  Next, the intake pressure deviation determination unit B that detects the deviation between the target intake pressure and the virtual intake pressure will be described.

  Here, when the deviation between the target intake pressure and the virtual intake pressure becomes equal to or greater than a predetermined value # 3 set in advance, an intake pressure increase deviation flag is input to one input terminal of the AND gate 82. The predetermined value # 3 is set to zero, for example.

  Next, the rapid deceleration engine stall avoidance determination unit C that detects the presence or absence of a request for reducing the response of the norm response time constant will be described.

  At the time of deceleration, the target intake pressure is determined in consideration of the brake performance and the amount of residual gas in the cylinder, and the throttle opening corresponding to the target intake pressure is controlled. In particular, during sudden deceleration, throttle opening control for avoiding sudden deceleration stall is performed in order to avoid engine stall due to a sudden decrease in engine speed. Specifically, the throttle opening is increased as the intake pressure decreases toward the target intake pressure. At this time, a low response non-acceleration standard response time constant is selected so that the opening degree changes according to a decrease in intake pressure.

  In view of this, a sudden deceleration engine stall avoidance determination unit C is provided so that a quick response norm response time constant for acceleration is not selected during sudden deceleration.

  When the engine speed is equal to or less than a predetermined value # 4 set in advance, a trigger is input to the first input terminal of the AND gate 74. Predetermined value # 4 sets a rotation speed that is a threshold value as to whether or not engine stall may occur during rapid deceleration.

  In addition, when the deviation between the previous value and the current value of the engine speed (previous value−current value) is greater than or equal to a predetermined value # 5 set in advance, a trigger is input to the second input terminal of the AND gate 74. Predetermined value # 5 sets a rotation speed that is a threshold value indicating whether or not the engine is suddenly decelerated to the extent that an engine stall may occur.

  Furthermore, a trigger is input to the third input terminal of the AND gate 74 when the idle switch is ON.

  When the deviation between the target intake pressure and the virtual intake pressure (target intake pressure−virtual intake pressure) is equal to or greater than a predetermined value # 6 set in advance, a trigger is input to one input terminal of the AND gate 75. The other terminal of the AND gate 75 receives the rapid deceleration engine stall flag at the time of the previous calculation. As described above, the predetermined value # 6 is such that, in the control for increasing the throttle opening in response to the decrease in the intake pressure, even if the throttle opening increases early with respect to the decrease in the intake pressure, the torque level difference due to this increases. This is a threshold value for determining whether or not the intake pressure has decreased to such an extent that it does not become. It should be noted that an almost upper limit value is set within a range in which the torque step does not feel strange. As a result, it is possible to prioritize drivability while minimizing the use of the non-acceleration standard response time constant.

  When the trigger from the AND gate 74 or the AND gate 75 is input to the OR gate 76, the rapid deceleration engine avoidance flag is set.

  In the sudden deceleration engine stall avoidance determination unit C configured as described above, when it is detected that the vehicle is decelerating suddenly, a trigger is input from the AND gate 74 to the OR gate 76, and the rapid deceleration engine stall avoidance flag is set. Since the sudden deceleration engine stall avoidance flag is input to the AND gate 75, the rapid deceleration engine stall avoidance flag remains on until the intake air pressure converges to the target intake air pressure.

  Next, the auxiliary machine load fluctuation determination unit D that detects the presence or absence of a request for reducing the response of the norm response time constant will be described.

  When the air conditioner is turned on, when the assist amount of power steering increases, or when other electric loads increase, the throttle opening is set to maintain the engine speed against the increase in the load. At this time, the reference response time constant for non-acceleration is selected. This is because, when compensating air is introduced for load fluctuations that do not involve an accelerator operation, generating torque with a high response gives the driver a sense of incongruity.

  Therefore, an auxiliary machine load fluctuation determination unit D is provided so that the acceleration time norm response time constant is not selected in such a case.

  When the air conditioner switch is switched from OFF to ON, when the power steering assist amount increases, or when other electrical loads increase, a trigger is input to each input terminal of the OR gate 77, respectively. When any of these triggers is input, the trigger is input to one input terminal of the OR gate 79.

  On the other hand, when the deviation between the target intake pressure and the virtual intake pressure is greater than or equal to a predetermined value # 7 set in advance, a trigger is input to one input terminal of the AND gate 78. The auxiliary load variation flag at the time of the previous calculation is input to the other input terminal of the AND gate 78.

  The predetermined value # 7 is temporarily switched to a reference response time constant for acceleration, and even if the throttle valve 14 is suddenly opened and air exceeding the target value flows in, the torque step caused by this causes the driver to feel uncomfortable. Set a value in the vicinity of the upper limit of the intake pressure range that fits within the limit. By setting the value to approximately the upper limit, it is possible to give priority to drivability while minimizing the use of the non-acceleration standard response time constant.

  In the auxiliary load variation determination unit D configured as described above, once the auxiliary load such as an air conditioner increases, the auxiliary load variation flag remains on until the intake pressure converges to the target intake pressure.

  Next, the idling state determination unit E that detects whether or not the idling operation state is present will be described.

  The determination unit determines that the vehicle is in a stopped state. When the engine speed is equal to or less than a predetermined value # 8 set in advance, a trigger is input to the first input terminal of the AND gate 80. In addition, when the vehicle speed is equal to or lower than a predetermined value # 9 set in advance, a trigger is input to the second input terminal of the AND gate 80. Further, a trigger is input to the third input terminal of the AND gate 80 when the idle switch is ON.

  When these three triggers are input, an idle state flag is set.

  The NOR gate 81 outputs 1 as the operator # 1 when none of the rapid deceleration engine avoidance flag, auxiliary load fluctuation flag, and idling state flag is set, and this operator # 1 is input to the AND gate 82. The

  The AND gate 82 outputs 1 as the operator # 2 when the operator # 1 (= 1) and the intake pressure increase deviation flag are input. The operator # 2 is input to the OR gate 83.

  In the OR gate 83, when either the acceleration intention detection flag or the operator # 2 (= 1) is input, the time constant switching determination flag is set. This time constant switching determination flag is input to the block B54 in FIG. 4. When the flag is set, the time is switched to the acceleration reference response time constant. When the flag is not set, the non-acceleration time reference response time constant is switched. .

  As described above, according to the present embodiment, the following effects can be obtained.

  (1) Since the target throttle opening is calculated using the reference response time constant for acceleration and the reference response time constant for non-acceleration, and using the reference response time constant selected by the switching determination unit B53, The acceleration response can be improved or the engine rotation stability can be improved.

  (2) Since the acceleration response time constant is higher than the non-acceleration time response response constant, acceleration is mainly required for high response and low response is required to ensure stability. It becomes the reference response time constant of the characteristic according to the non-accelerated time.

  (3) Since the reference response time constant is switched based on the deviation between the target intake pressure and the virtual intake pressure, the throttle opening is dominant in the direction of increasing the intake pressure, and the engine speed is governed in the direction of decreasing the intake pressure. The norm response time constant matches the target engine characteristics.

  (4) Since the norm response time constant is switched according to whether the driver intends to accelerate, the appropriate norm response time constant can be switched according to the driver's request.

  (5) When there is an intention to accelerate, the normal response time constant for acceleration is selected, and when there is no intention to accelerate, the normal response time constant for non-acceleration is selected. When the user does not intend to accelerate, the standard response time constant for non-acceleration is selected, and the stability of engine rotation can be improved.

  (6) Since the norm response time constant is switched according to whether or not there is a request to reduce the response of the norm response time constant, the engine rotation stability can be reduced when the engine stall is avoided during sudden deceleration or when the load on the auxiliary machinery increases. Can be improved.

  (7) Since the reference response time constant for non-acceleration is selected in the idling state, the stability of engine rotation during idling can be improved.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope of the technical idea described in the claims.

It is a block diagram of the system to which this embodiment is applied. It is a main block diagram of intake air amount control. It is an example of a model for calculating the air intake passage pressure P _M. It is a diagram illustrating a configuration for calculating the nominal response time constant τP _m. It is a figure which shows an example of a norm response time constant map. It is a figure which shows the detail of a switching determination part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combustion chamber 2 Cylinder head 3 Cylinder block 4 Piston 5 Intake passage 6 Exhaust passage 7 Intake valve 8 Exhaust valve 9 Variable valve mechanism 10 Exhaust camshaft 11 Fuel injection valve

Claims (4)

An acceleration time reference response time constant calculating means for calculating an acceleration time reference response time constant;
A non-acceleration normal response time constant calculating means for calculating a non-acceleration normal response time constant;
As a driving state , whether the driver intends to accelerate, whether there is a request to reduce the response of the norm response time constant, means for calculating the target intake pressure, and means for calculating the virtual intake pressure corresponding to the current intake pressure Driving state detecting means for detecting a deviation between the target intake pressure and the virtual intake pressure based on the calculation result of
When there is an intention to accelerate, the reference response time constant for acceleration is selected, and when there is no intention to accelerate, a reference response time constant switching determining means for selecting the reference response time constant for non-acceleration , and
Target throttle opening calculation means for calculating the target throttle opening using the reference response time constant selected by the reference response time constant switching determination means;
With
The reference response time constant switching determination means determines whether or not the virtual intake pressure has converged to the target intake pressure based on a deviation between the target intake pressure and the virtual intake pressure. An intake control device for an internal combustion engine. Intake air control system for an internal combustion engine, wherein said acceleration nominal response time constant for the time response than the non-acceleration for nominal response time constant in the high I請 Motomeko 1. The operating state detection means detects the presence or absence of a request to reduce the response of the normative response time constant,
The intake control apparatus for an internal combustion engine according to claim 1 or 2 , wherein the reference response time constant switching determination unit selects the reference response time constant for non-acceleration when there is a request to reduce the responsiveness. The operating state detecting means detects whether or not the idle operating state,
The intake control apparatus for an internal combustion engine according to any one of claims 1 to 3, wherein the reference response time constant switching determination unit selects a reference response time constant for non-acceleration when the engine is in an idling operation state.

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