JP4525266B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device.

The relationship between the volume flow ratio, which is the value obtained by dividing the intake air amount by the maximum intake air amount at the rotational speed when the intake air amount is obtained, and the value obtained by dividing the throttle valve opening area by the exhaust amount and the engine rotational speed Focusing on the fact that they exhibit substantially the same characteristics regardless of the engine speed, there is a technique for obtaining a target intake air amount and a target throttle valve opening area using this relationship (see Patent Document 1).
JP-A-11-182298

  By the way, since the maximum output at the same stroke volume and the same rotational speed is directly affected by the weight of the intake air, there are two methods for expressing the magnitude of the amount of air flowing into the cylinder every cycle on the basis of the total stroke volume. One is volumetric efficiency and the other is filling efficiency. Among them, volumetric efficiency represents the superiority or inferiority of the engine based on the ambient atmospheric conditions where the engine is operated, and is generally defined by the formula (Supplement 1-1) described later.

  If the relationship between the volumetric efficiency and the flow rate of the intake air that flows into the combustion chamber when the intake valve is opened (hereinafter sometimes simply referred to as “flow velocity”) can be described regardless of the engine model, Since it is not necessary to adapt to each model, it greatly contributes to shortening the development period of engine design.

  However, this problem has not been solved at present.

  For this reason, as a result of various experiments conducted by the inventor, the inventors succeeded in creating a new intake model that represents the relationship between volumetric efficiency and flow velocity. That is, an object of the present invention is to provide an engine control device that is excellent in versatility as an engine intake model.

The present invention provides a control apparatus for an engine having a throttle valve in an intake passage and having a function as a pump for sucking intake air downstream of the throttle valve into a combustion chamber.
The value obtained by dividing the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened by the gas substance quantity when the total stroke volume is satisfied with the gas downstream of the throttle valve when the throttle valve is fully opened is when the throttle valve is fully opened. The volumetric efficiency (ηvwot) , based on the value obtained by dividing the volumetric efficiency (ηvwot) when the throttle valve is fully opened by the throttle valve opening area (Atvo) , or the virtual Mach number that is a value obtained by dividing the virtual flow rate by the sound velocity To calculate
The calculated virtual velocity or based on the number of virtual Mach, normalized volumetric efficiency value corresponds obtained by dividing the body volume efficiency by the throttle valve fully open when the volumetric efficiency (ηvwot), the throttle valve downstream of the intake pressure and (P2) Throttle the ratio throttle valve upstream intake air pressure ratio is a valve upstream of the intake pressure (P1) (P2 / P1) , a throttle valve wherein the ratio of the throttle valve downstream of the intake air density ([rho] 2) and the throttle valve upstream of the intake air density (.rho.1) Any one of the front and rear intake density ratio (ρ2 / ρ1) is calculated, and the calculated normalized volume efficiency, the throttle valve front and rear intake pressure ratio (P2 / P1), and the throttle valve front and rear intake density ratio (ρ2 / ρ1) are calculated. The volumetric efficiency is calculated based on any one of them.

The present invention also provided with a throat portion throttle valve in the intake passage, the engine control apparatus having a function as a pump to suck air in the throat portion downstream of the throttle valve to the combustion chamber, one cycle when the throttle valve fully opened The value obtained by dividing the amount of cylinder fresh air intake per cylinder when the total stroke volume is filled with the gas downstream of the throttle valve when the throttle valve is fully opened is the volume efficiency when the throttle valve is fully opened. virtual velocity on the basis of the fully open time volumetric efficiency divided by the throttle valve opening area, or the virtual velocity to calculate the number of virtual Mach is divided by the sound velocity, the calculated virtual velocity or based on the number of virtual Mach calculating a normalized volumetric efficiency, multiplication of the normalized volumetric efficiency in the throttle valve fully open when the volumetric efficiency (ηvwot) The volumetric efficiency ηv is calculated, the filling efficiency estimated value ηcest is calculated based on the volumetric efficiency ηv, the filling efficiency is detected, and the ratio or difference between the filling efficiency detected value ηcreal and the filling efficiency estimated value ηcest is calculated. Then, it is configured to determine whether or not there is a closed failure in the EGR device based on this ratio or difference.

Further, the present invention provides a cylinder intake per cycle when the throttle valve is fully opened in an engine control device having a throttle valve in the intake passage and a function as a pump for sucking intake air downstream of the throttle valve into the combustion chamber. The volumetric efficiency when the throttle valve is fully open is defined as the volumetric efficiency when the throttle valve is fully open. Based on the value divided by the throttle valve opening area, the virtual flow velocity , or the virtual Mach number that is the value obtained by dividing the virtual flow velocity by the sound velocity, is calculated, and the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number. The volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency (ηvwot) when the throttle valve is fully opened. The charging efficiency estimated value ηcest is calculated based on the volumetric efficiency ηv, the charging efficiency is detected, the ratio or difference between the charging efficiency detected value ηcreal and the charging efficiency estimated value ηcest is calculated, and the ratio or difference is calculated. Based on this, it is configured to determine whether or not there is an open failure in the EGR device.

Further, the present invention provides a cylinder intake per cycle when the throttle valve is fully opened in an engine control device having a throttle valve in the intake passage and a function as a pump for sucking intake air downstream of the throttle valve into the combustion chamber. The volumetric efficiency when the throttle valve is fully open is defined as the volumetric efficiency when the throttle valve is fully open. Based on the value divided by the throttle valve opening area, the virtual flow velocity , or the virtual Mach number that is the value obtained by dividing the virtual flow velocity by the sound velocity, is calculated, and the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number. The volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency (ηvwot) when the throttle valve is fully opened. The flow rate is calculated by multiplying the volume efficiency ηv and the virtual flow rate.

Further, the present invention provides a cylinder intake per cycle when the throttle valve is fully opened in an engine control device having a throttle valve in the intake passage and a function as a pump for sucking intake air downstream of the throttle valve into the combustion chamber. The volumetric efficiency when the throttle valve is fully open is defined as the volumetric efficiency when the throttle valve is fully open. Based on the value divided by the throttle valve opening area, the virtual flow velocity , or the virtual Mach number that is the value obtained by dividing the virtual flow velocity by the sound velocity, is calculated, and the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number. The volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency (ηvwot) when the throttle valve is fully opened. The estimated charging efficiency value ηcest is calculated based on the volumetric efficiency ηv, the fuel supply amount is calculated based on the estimated charging efficiency value ηcest, and the fuel supply amount is supplied to the engine.

Further, the present invention provides a cylinder intake per cycle when the throttle valve is fully opened in an engine control device having a throttle valve in the intake passage and a function as a pump for sucking intake air downstream of the throttle valve into the combustion chamber. The volumetric efficiency when the throttle valve is fully open is defined as the volumetric efficiency when the throttle valve is fully open. Based on the value divided by the throttle valve opening area, the virtual flow velocity , or the virtual Mach number that is the value obtained by dividing the virtual flow velocity by the sound velocity, is calculated, and the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number. The volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency (ηvwot) when the throttle valve is fully opened. The filling efficiency estimated value ηcest is calculated based on the volumetric efficiency ηv, the filling efficiency is detected, and the output of the filling efficiency detecting means is abnormal based on the filling efficiency detected value ηcreal and the filling efficiency estimated value ηcest. It is configured to determine whether or not.

Further, the present invention provides a cylinder intake per cycle when the throttle valve is fully opened in an engine control device having a throttle valve in the intake passage and a function as a pump for sucking intake air downstream of the throttle valve into the combustion chamber. The volumetric efficiency when the throttle valve is fully open is defined as the volumetric efficiency when the throttle valve is fully open. Based on the value divided by the throttle valve opening area, the virtual flow velocity , or the virtual Mach number that is the value obtained by dividing the virtual flow velocity by the sound velocity, is calculated, and the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number. The volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency (ηvwot) when the throttle valve is fully opened. The actual volume efficiency ηvreal is detected, and based on the actual volume efficiency ηvreal and the calculated volume efficiency ηv, it is determined whether there is an abnormality in the output of the actual volume efficiency detection means.

Further, the present invention provides a cylinder intake per cycle when the throttle valve is fully opened in an engine control device having a throttle valve in the intake passage and a function as a pump for sucking intake air downstream of the throttle valve into the combustion chamber. The volumetric efficiency when the throttle valve is fully open is defined as the volumetric efficiency when the throttle valve is fully open. Based on the value divided by the throttle valve opening area, the virtual flow velocity , or the virtual Mach number that is the value obtained by dividing the virtual flow velocity by the sound velocity, is calculated, and the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number. The volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency (ηvwot) when the throttle valve is fully opened. And calculating a charging efficiency estimated value ηcest based on the volumetric efficiency ηv, detecting the charging efficiency, and a difference or ratio between the actual charging efficiency detection value and the charging efficiency estimated value in a region where intake pulsation may occur. Measuring the time or number of times that exceeded a predetermined value, and determining whether or not there is an abnormality with a large positive error associated with intake pulsation in the output of the charging efficiency detection means depending on whether or not this measured value exceeds a determination value, The target throttle valve opening is calculated according to the accelerator operation amount and the engine speed, and the target throttle valve opening is determined so that the intake pulsation does not occur when there is an abnormality with a large plus error associated with the intake pulsation based on the determination result. The throttle valve is limited to a value, and the throttle valve is controlled so as to obtain a target throttle valve opening degree limited to the predetermined value.

Further, the present invention provides a cylinder intake per cycle when the throttle valve is fully opened in an engine control device having a throttle valve in the intake passage and a function as a pump for sucking intake air downstream of the throttle valve into the combustion chamber. The volumetric efficiency when the throttle valve is fully open is defined as the volumetric efficiency when the throttle valve is fully open. Based on the value divided by the throttle valve opening area, the virtual flow velocity , or the virtual Mach number that is the value obtained by dividing the virtual flow velocity by the sound velocity, is calculated, and the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number. The volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency (ηvwot) when the throttle valve is fully opened. The actual volumetric efficiency ηvreal is detected, and the time or number of times when the difference or ratio between the actual volumetric efficiency and the calculated volumetric efficiency exceeds a predetermined value in a region where intake pulsation may occur is measured. It is determined whether the output of the actual volumetric efficiency detecting means has a large plus error due to intake pulsation depending on whether the value exceeds a determination value, and the target throttle valve is determined according to the accelerator operation amount and the engine speed. The opening is calculated, and the target throttle valve opening is limited to a predetermined value so that the intake pulsation does not occur when there is an abnormality with a large positive error due to the intake pulsation from the determination result. The throttle valve is controlled so that the target throttle valve opening can be obtained.

According to the present invention, the amount of cylinder intake fresh air per cycle when the throttle valve is fully open is divided by the amount of gas when the total stroke volume is filled with the gas downstream of the throttle valve when the throttle valve is fully open. value and throttle valve fully open when the volumetric efficiency (ηvwot) and the throttle valve fully open when the volumetric efficiency (ηvwot) a throttle valve opening area (Atvo) virtual velocity u based on the values divided by ', or the virtual velocity at the speed of sound A virtual Mach number M ′ that is a divided value is calculated. Based on the calculated virtual flow velocity u ′ or virtual Mach number M ′, normalized volume efficiency, pressure ratio before and after the throat part (P2 / P1), and before and after the throat part Any one of the density ratios (ρ2 / ρ1) is calculated, and the calculated normalized volumetric efficiency, the throttle valve front-rear intake pressure ratio (P2 / P1), and the throttle valve front-rear intake density The volumetric efficiency is calculated based on any one of the ratios (ρ2 / ρ1) .

  In this case, the relationship between the virtual flow velocity u ′ and the virtual Mach number M ′ and the normalized volume efficiency is as shown in FIG. 5 (a), FIG. 5 (b), FIG. 6 (a), and FIG. 6 (b). In addition, the present inventors have confirmed through experiments that any type of general engine shows a high correlation. Meaning that any general engine shows a high correlation means that the characteristics shown in FIG. 5 (a), FIG. 5 (b) or FIG. 6 (a) and FIG. 6 (b) are related to the engine model. This means that the engine can be used in common, and thus a versatile intake model for the engine could be constructed. For this reason, the engine development period can be significantly shortened by using this versatile intake model.

  In this case, the relationship between the target normalized volumetric efficiency, the target virtual flow velocity tu ′ and the target virtual Mach number tM ′ is the same even if “target” is attached, and FIG. 5 (a), FIG. 5 (b) or FIG. As shown in FIGS. 6 (a) and 6 (b), the present inventor has confirmed through experiments that any type of general engine shows a high correlation. That is, according to the present invention, a general-purpose intake model of the engine can be newly constructed. By using this general-purpose intake model, the engine development period can be greatly shortened.

Further, according to the present invention, the amount of cylinder intake fresh air per cycle when the throttle valve is fully opened is the amount of gas when the total stroke volume is filled with the gas downstream of the throttle valve when the throttle valve is fully opened. The divided value is the volumetric efficiency when the throttle valve is fully open , and the virtual flow rate based on the value obtained by dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area , or the virtual Mach number that is the value obtained by dividing this virtual flow rate by the speed of sound. And the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number, and the volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency when the throttle valve is fully opened (ηvwot). An estimated filling efficiency value ηcest is calculated based on the volumetric efficiency ηv, an actual filling efficiency ηcreal is detected, and the actual filling efficiency ηcreal and the estimated filling efficiency value ηcest And calculating whether or not there is a closed failure in the EGR device based on the deviation rate tmp, so that a versatile intake model for the engine can be newly constructed. Furthermore, a flow sensor is provided in the EGR passage to diagnose whether EGR gas is actually flowing in the EGR region (if EGR gas is not flowing, there is a closed failure in the EGR valve as the EGR device) Without diagnosing whether or not EGR gas is actually flowing in the EGR region by providing a temperature sensor downstream (if the temperature downstream of this EGR valve is substantially equal to the intake air temperature, the EGR valve has a closed failure) It is possible to diagnose (detect) whether or not the EGR valve has a closed failure, which eliminates the need to use a sensor for detecting the EGR gas flow rate or EGR gas temperature. Excellent in manner.

Further, according to the present invention, the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened is the gas substance quantity when the total stroke volume is filled with the gas downstream of the throttle valve when the throttle valve is fully opened. the division value as the throttle valve fully open when the volumetric efficiency, a virtual velocity on the basis of a value obtained by dividing the throttle valve fully open when the volumetric efficiency in the throttle valve opening area, or the number of virtual Mach is a value obtained by dividing the virtual velocity at the speed of sound And the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number, and the volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency when the throttle valve is fully opened (ηvwot). An estimated filling efficiency η cest is calculated based on the volumetric efficiency, an actual filling efficiency η creal is detected, and the actual filling efficiency η creal and the estimated filling efficiency η cest are calculated. Is calculated, and it is determined whether or not there is an open failure in the EGR device based on this deviation rate, so that a general-purpose intake model for the engine can be newly constructed, and further the EGR passage A flow sensor is provided to diagnose whether EGR gas is actually flowing in the non-EGR region (if EGR gas is flowing, there is an open failure in the EGR valve as the EGR device) or downstream of the EGR valve An EGR valve is provided without diagnosing whether or not EGR gas is actually flowing in the non-EGR region by providing a temperature sensor (if the temperature downstream of the EGR valve is higher than the intake air temperature, the EGR valve has an open failure). This makes it possible to diagnose (detect) whether or not an open failure has occurred, thereby eliminating the need to use a sensor for detecting the EGR gas flow rate, EGR gas temperature, etc. The

Further, according to the present invention, the amount of cylinder intake fresh air per cycle when the throttle valve is fully opened is the amount of gas when the total stroke volume is filled with the gas downstream of the throttle valve when the throttle valve is fully opened. The divided value is the volumetric efficiency when the throttle valve is fully opened , and the virtual flow velocity u ′ based on the value obtained by dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area , or a virtual Mach that is a value obtained by dividing the virtual flow velocity by the sound velocity Calculate the number M ′, calculate the normalized volumetric efficiency based on the calculated virtual flow velocity u ′ or the virtual Mach number M ′, and multiply the normalized volumetric efficiency by the volumetric efficiency (ηvwot) when the throttle valve is fully opened. Since the volumetric efficiency ηv is calculated and the volumetric efficiency ηv is multiplied by the virtual flow velocity u ′, or the volumetric efficiency ηv is multiplied by the virtual Mach number M ′ and the sound velocity c, the flow velocity u is calculated. On versatility is intake model engine is new can be constructed, it is possible to further calculate also accurately the flow rate of intake air flowing through the butterfly type throttle valve unit in the region close to the butterfly type throttle valve is fully opened.

Further, according to the present invention, the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened is the gas substance quantity when the total stroke volume is filled with the gas downstream of the throttle valve when the throttle valve is fully opened. The divided value is the volumetric efficiency when the throttle valve is fully open , and the virtual flow rate based on the value obtained by dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area , or the virtual Mach number that is the value obtained by dividing this virtual flow rate by the speed of sound. And the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number, and the volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency when the throttle valve is fully opened (ηvwot). Since the estimated charging efficiency value ηcest is calculated based on the volumetric efficiency ηv and the fuel supply amount is calculated based on the estimated charging efficiency value ηcest, the versatility of the engine In addition to being able to construct a new intake model, there are also expensive parts such as an air flow meter required for an L-Jetronic fuel injection device and a pressure sensor required for a D-Jetronic fuel injection device. Even if not used, fuel injection can be performed by estimating the amount of cylinder intake per intake.

Further, according to the present invention, the amount of cylinder intake fresh air per cycle when the throttle valve is fully opened is the amount of gas when the total stroke volume is filled with the gas downstream of the throttle valve when the throttle valve is fully opened. The divided value is the volumetric efficiency when the throttle valve is fully open , and the virtual flow rate based on the value obtained by dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area , or the virtual Mach number that is the value obtained by dividing this virtual flow rate by the speed of sound. And the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number, and the volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency when the throttle valve is fully opened (ηvwot). Based on the assumption that an estimated charging efficiency value ηcest is calculated based on the volumetric efficiency ηv, and a fuel supply amount is calculated based on the estimated charging efficiency value ηcest. A value obtained by adding a predetermined difference or rate to the estimated efficiency value ηcest is calculated as an abnormality determination upper limit value ηcestMAX and an abnormality determination lower limit value ηcestMIN, and the charging efficiency is detected. The charging efficiency detection value ηcreal exceeds the abnormality determination upper limit value ηcestMAX. The abnormality determination upper limit value ηcestMAX is limited to the abnormality determination lower limit value ηcestMIN when the charging efficiency detection value ηcreal is lower than the abnormality determination lower limit value ηcestMIN. Alternatively, when the state limited to the abnormality determination lower limit value continues for a predetermined time or longer, it is determined that an abnormality has occurred in the output of the charging efficiency detection means, or a throttle valve is provided in the intake passage, and the throttle valve in the engine control system having a function as a pump to suck downstream of the intake into the combustion chamber, the throttle valve full The volumetric efficiency when the throttle valve is fully opened is divided by the amount of cylinder intake fresh air per cycle at the time when the total stroke volume is filled with the gas downstream of the throttle valve when the throttle valve is fully open. , virtual velocity on the basis of the throttle valve fully open when volumetric efficiency divided by the throttle valve opening area or the virtual velocity to calculate the number of virtual Mach is divided by the velocity of sound, virtual velocity or virtual Mach and this calculated, The normalized volumetric efficiency is calculated based on the number, the volumetric efficiency ηv is calculated by multiplying this normalized volumetric efficiency by the throttle valve fully open volumetric efficiency (ηvwot), and the actual volumetric efficiency ηvreal is detected. Based on ηvreal and the calculated volumetric efficiency ηv, it is determined whether there is an abnormality in the output of the actual volumetric efficiency detecting means. In addition to being able to newly build Dell, it is possible to further diagnose the filling efficiency detection means and the actual volume efficiency detection means.

Further, according to the present invention, the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened is the gas substance quantity when the total stroke volume is filled with the gas downstream of the throttle valve when the throttle valve is fully opened. The divided value is the volumetric efficiency when the throttle valve is fully open , and the virtual flow rate based on the value obtained by dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area , or the virtual Mach number that is the value obtained by dividing this virtual flow rate by the sound speed And the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity or virtual Mach number, and the volumetric efficiency ηv is calculated by multiplying the normalized volumetric efficiency by the volumetric efficiency when the throttle valve is fully opened (ηvwot). An estimated charging efficiency value ηcest is calculated based on the volumetric efficiency ηv, the charging efficiency is detected, and the detected charging efficiency value ηcreal in a region where intake pulsation may occur The time or number of times that the difference or ratio of the estimated charging efficiency value ηcest exceeds a predetermined value is measured, and an abnormality in which the plus error due to intake pulsation is large in the output of the charging efficiency detecting means depending on whether or not this measured value exceeds the judgment value The target throttle valve opening is calculated according to the accelerator operation amount and the engine speed, and the intake pulsation does not occur when there is an abnormality with a large positive error due to the intake pulsation based on the determination result. the target throttle valve opening is limited to up to a predetermined value, and controls the throttle valve so that the target throttle valve opening degree is limited to the predetermined value is obtained, or provided with a throttle valve in the intake passage, the throttle in the engine control system having a function as a pump to suck air valve downstream to the combustion chamber, per 1 cycle at throttle valve fully opened The value obtained by dividing the cylinder intake fresh air substance amount by the gas substance amount when the total stroke volume is satisfied with the gas downstream of the throttle valve when the throttle valve is fully opened is the volume efficiency when the throttle valve is fully opened. Calculate the virtual flow velocity based on the value obtained by dividing the time volumetric efficiency by the opening area of the throttle valve , or the virtual Mach number that is the value obtained by dividing the virtual flow velocity by the sound velocity, and then normalize based on the calculated virtual flow velocity or virtual Mach number. The volumetric efficiency is calculated, the volumetric efficiency ηv is calculated by multiplying this normalized volumetric efficiency by the volumetric efficiency (ηvwot) when the throttle valve is fully opened , the actual volumetric efficiency ηvreal is detected, and the region where intake pulsation may occur And measuring the time or number of times that the difference or ratio between the actual volume efficiency and the calculated volume efficiency exceeds a predetermined value, and whether or not the measured value exceeds a determination value, It is determined whether the output of the volumetric efficiency detection means has an abnormality with a large positive error due to intake pulsation, the target throttle valve opening is calculated according to the accelerator operation amount and the engine speed, and the intake pulsation is calculated from the determination result. The target throttle valve opening is limited to a predetermined value so that intake pulsation does not occur when there is an abnormality with a large positive error, and the throttle is adjusted so that the target throttle valve opening limited to this predetermined value is obtained. Since the valve is controlled, it is possible to construct a new intake model with a general purpose engine, and when an abnormality with a large positive error due to intake pulsation occurs in the output of the charging efficiency detection means or actual volume efficiency detection means Also, it is possible to prevent the drivability from deteriorating.

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

  FIG. 1 is a block diagram of the volumetric efficiency calculating means 11 of the first embodiment, and the volumetric efficiency calculating means 11 is provided in the engine controller 10.

  Although a specific configuration of the engine is not shown in FIG. 1, any system may be used as long as the intake air amount introduced into the combustion chamber of the engine is controlled depending on the change in the flow velocity of the intake air in the intake pipe. That is, the engine has a function as a pump that provides a throat portion in the intake passage and sucks intake air downstream of the throat portion into the combustion chamber. Specifically, as shown in the lower part of FIG. 43, the intake air sucked into the intake passage 22 by the pump function of the engine is metered by a throttle valve 21 (throat portion) provided in the intake passage 22, After being temporarily stored in the collector 27, it is distributed and supplied from the intake port to the combustion chamber (cylinder) of each cylinder. A fuel injection valve 29 is provided in the intake port of each cylinder. Upon receipt of a signal from the engine controller 10, the fuel injection valve 29 injects and supplies fuel at a predetermined time. The gas burned in the combustion chamber is discharged to the exhaust passage 23. A catalyst such as a three-way catalyst is provided in the exhaust passage, where harmful components in the exhaust are purified.

  Before explaining the block diagram of FIG. 1, “normalized volume efficiency” and “virtual flow velocity” newly introduced in the present invention will be explained.

  Now, if the relationship between volumetric efficiency and flow velocity can be described regardless of the engine model, it is not necessary to adapt to each engine model, which greatly contributes to shortening the development period of the engine design. For this reason, the intake model of the present invention was created as a result of various experiments conducted by the present inventor. FIG. 6A shows an experimental result in an equilibrium state of the engine obtained by the inventor for the first time. FIG. 6 (a) shows the relationship between the virtual flow velocity and the normalized volume efficiency. According to this characteristic, there is no place where the characteristic changes suddenly. Therefore, the normalized volume efficiency can be accurately obtained from the virtual flow velocity. In contrast, it can be seen that the virtual flow velocity can be obtained with high accuracy from the normalized volume efficiency.

  Here, terms such as “volumetric efficiency”, “filling efficiency”, “volumetric efficiency when the throttle valve is fully opened”, and “normalized volumetric efficiency” will be described. Definitions of volumetric efficiency and filling efficiency in a general sense are as follows.

Volumetric efficiency = Cylinder intake fresh air quantity per cycle
/ Amount of gaseous material when the total stroke volume is met in atmospheric conditions
... (Supplement 1-1)
Filling efficiency = Cylinder intake fresh air quantity per cycle
/ Gas mass when the total stroke volume is satisfied in the standard state
... (Supplement 1-2)
On the other hand, in the present invention, the volumetric efficiency ηvwot when the throttle valve is fully opened is uniquely defined as follows.

ηvwot = amount of cylinder fresh air per cycle
/ Gas mass when the total stroke volume is filled with the gas downstream of the throat
... (Supplement 1-3)
These three formulas all have the common feature that they are normalized by the total stroke volume (displacement), but the volumetric efficiency of (Supplement 1-1) is the pump suction capacity of the engine that does not depend much on environmental conditions. On the other hand, the charging efficiency of the formula (Supplement 1-2) indicates the absolute amount of intake air.

  On the other hand, the volumetric efficiency ηvwot when the throttle valve is fully opened in (Supplement 1-3) is an indicator of how much air the cylinder discharges from the manifold rather than the engine. It is an index showing the relative pump suction capacity of the engine excluding the influence of the state change.

Assuming that the volumetric efficiency ηvwot of (Supplement 1-1) and the throttle valve fully opened ηvwot of (Supplement 1-3) is assumed that the upstream and downstream of the throat section are isothermal, the upstream pressure of the throat section P1, the throat downstream pressure is P2,
ηvwot = volume efficiency × (P1 / P2) (Supplement 1-4)
It becomes. That is, when the throttle valve is fully open (WOT), P1≈P2 or atmospheric condition≈the throat part downstream state.
ηvwot ≒ volume efficiency | _wot ... (Supplement 1-5)
And the volumetric efficiency ηvwot when the throttle valve is fully open does not change so much depending on the throat upstream pressure P1, the throat downstream pressure P2 or the throttle valve opening, etc. “Volume efficiency” is defined as in (Supplement 1-3).

  Note that the three efficiencies are defined (normalized) in a state where the denominator is in a certain state, such as (complement 1-1), (complement 1-2), and (complement 1-3). Therefore, 1.0 is not the upper limit for any efficiency. For example, the volumetric efficiency and volumetric efficiency when the throttle valve is fully open increase 1.0 by the dynamic effect of the intake pipe, the supercharging by the turbocharger, the scavenging effect of the residual gas due to the overlap of the intake and exhaust valves and the intake and exhaust pulsation In some cases, the filling efficiency becomes 1.0 or more if the denominator is smaller than the numerator, as in the case where the temperature is lower than the standard state.

  The throat portion is a portion that throttles intake air in the middle of the intake passage, for example, a portion where a throttle valve is provided. Here, in order to clarify that the engine is not limited to an engine having a butterfly type throttle valve, the expression “throat portion” is used instead of the throttle valve portion.

  Next, the definition of “normalized volumetric efficiency” used on the vertical axis of FIG. 6A is as follows.

Normalized volumetric efficiency [anonymous number] = volumetric efficiency [anonymous number]
/ Volumetric efficiency when throttle valve is fully open [unknown number]
... (Supplement 2)
That is, the normalized volumetric efficiency is a value obtained by dividing the volumetric efficiency of the above (complement 1-1) by the volumetric efficiency ηvwot when the throttle valve is fully opened of the (complementary 1-3).

  On the other hand, the definition of “virtual flow velocity” on the horizontal axis of FIG. 6A is a value obtained by dividing the flow velocity of intake air by the normalized volume efficiency of the above (Supplement 1-3), that is, the following equation.

Virtual flow velocity [m / s] = flow velocity [m / s] / normalized volume efficiency [anonymous number] (Supplement 3)
This virtual flow velocity u ′ is a value created by the present inventor for the first time. As “virtual” is attached to the virtual flow velocity, the virtual flow velocity u ′ is not a physical quantity that actually exists, but a value conceived for trial and error. For comparison, when the relationship between the flow rate, which is a physical quantity that actually exists, and the normalized volumetric efficiency is shown superimposed in FIG. 6A, when the flow rate is used, the predetermined value v1 as shown by the alternate long and short dash line is shown. It can be seen that the characteristic suddenly falls before the point and the characteristic is cut off at the predetermined value v1. This is because when the flow velocity itself becomes faster, it is physically limited by the sound velocity and converges, so when the flow velocity is in the region near the sound velocity, there is no correlation with parameters such as normalized volume efficiency. is there. That is, the predetermined value v1 on the horizontal axis in FIG. 6A corresponds to a value when the sound speed c is substituted for the flow velocity in the above (complement 3).

  On the other hand, when the virtual flow velocity u ′, which is a value obtained by further dividing the flow velocity by the normalized volume efficiency, is taken on the horizontal axis as shown in FIG. 6A, the characteristic does not end at the predetermined value v1. A gentle characteristic is obtained up to a flow velocity region exceeding the sound velocity c. Based on this characteristic, the normalized volumetric efficiency can be obtained from the virtual flow velocity u ′, and conversely, the virtual flow velocity u ′ can be obtained accurately from the normalized volumetric efficiency. A value obtained by dividing the flow velocity by the normalized volume efficiency as in the above (Supplement 3) is a physical quantity that is a value related to the flow velocity but does not exist in reality, and therefore, “virtual” is attached.

  When the virtual flow velocity u ′ is defined as in the above (Supplement 3), a clearer relationship shown in FIG. 5A can be obtained between the virtual flow velocity u ′ and the normalized volume efficiency. This is the first item found by the inventor. That is, FIG. 6A shows real numbers on both the horizontal and vertical axes, whereas FIG. 5A shows natural logarithms on both the horizontal and vertical axes. According to the logarithmic display characteristic shown in FIG. 5A, the normalized volumetric efficiency is substantially constant in a region where the virtual flow velocity u ′ is small (that is, a region where the throttle valve opening is large), and a virtual value larger than the predetermined value v2. In the region of the flow velocity u ′ (that is, the region where the throttle valve opening is small), a substantially linear relationship is obtained in which the normalized volumetric efficiency decreases as the virtual flow velocity u ′ increases.

  The inventor has confirmed through experiments that the relationship between the virtual flow velocity u ′ and the normalized volumetric efficiency shown in FIGS. 5A and 6A shows a high correlation in any type of general engine. ing. The meaning that a high correlation is shown in any model as long as it is a general engine means that the characteristics shown in FIGS. 5A and 6A can be used in common regardless of the engine model. This means that there is no need to refit even if they differ. The meaning of a general engine means that a vehicle equipped with a supercharger is excluded. However, this does not mean that the present invention cannot be applied to an engine equipped with a supercharger, and can also be applied to an engine equipped with a supercharger by performing a predetermined correction on the normalized volume efficiency (No. 1). 9 will be described later).

  The flow velocity on the right side of the above (Supplement 3) is the flow velocity of the intake air flowing from the intake port into the combustion chamber. In this case, it is assumed that there is no change in the intake air density downstream of the throttle valve 21. Yes. In addition, the actual intake flow rate is not constant from when the intake valve is opened until it is closed, but here it is considered as an average flow rate for simplicity.

  More specifically, the virtual flow rate may be modified such as taking the reciprocal (described later in the sixteenth embodiment) or the unit may be changed. Here, changing the unit means converting from the virtual flow velocity u 'to the flow velocity (described later in the twelfth embodiment). Furthermore, physical parameters other than the virtual flow velocity can be used. For example, FIG. 5B and FIG. 6B show the horizontal axis replaced with the virtual Mach number M ′. Here, the virtual Mach number M ′ is a value obtained by further dividing the virtual flow velocity u ′ by the sound velocity c, that is, a value defined by the following equation.

Virtual Mach number [nameless number] = virtual flow velocity [m / s] / sound velocity [m / s] (Supplement 4)
The normalized volumetric efficiency on the vertical axis of FIGS. 5 (a), 5 (b), 6 (a), and 6 (b) is the same. If normalization is performed, physical parameters other than volumetric efficiency may be used. Is possible. For example, as shown in FIG. 7, the intake pressure upstream of the throttle valve 21 is P1, the intake density upstream of the throttle valve 21 is ρ1, the intake pressure downstream of the throttle valve 21 is P2, and the intake air density downstream of the throttle valve 21 is ρ2. Then, instead of the normalized volumetric efficiency, the throttle valve front-rear intake pressure ratio (P2 / P1) obtained by dividing the throttle valve 21 downstream pressure P2 by the throttle valve 21 upstream pressure P1 or the intake air density ρ2 downstream of the throttle valve 21 is determined as the throttle valve. 21 may be the throttle valve front / rear intake density ratio (ρ2 / ρ1) divided by the upstream intake density ρ1 (see FIGS. 5A, 5B, 6A, and 6B). .

Here, the flow rate on the right side of the above (complement 3) is: flow rate [m / s] = (total stroke volume [m ³ ] / throttle valve opening area [m ² ])
× (Engine rotation speed [rpm] / 120) (Supplement 5)
Therefore, if this is substituted into the above (complement 3) and the volume efficiency when the throttle valve is fully opened is substituted as the normalized volumetric efficiency on the right side of the (complement 3), the following equation is obtained.

Virtual flow velocity [m / s] = (total stroke volume [m ³ ] × volumetric efficiency when throttle valve is fully open
× (Engine speed [rpm] / 120))
/ Throttle valve opening area [m ² ] (Appendix 6)
The reason why the volumetric efficiency when the throttle valve is fully open is substituted as the normalized volumetric efficiency on the right side of Equation (3) is that the volumetric efficiency when the throttle valve 21 is fully open is between the downstream of the throttle valve 21 and the total stroke volume. This is because the volumetric efficiency is almost the same as the volumetric efficiency, so that the normalized volumetric efficiency can be obtained with relatively high accuracy even if the volumetric efficiency is replaced with the volumetric efficiency when the throttle valve is fully opened.

  Further, since the flow velocity changes depending on the sound velocity c, the virtual flow velocity may be obtained by the following equation instead of the (Appendix 6) equation if the change is also taken into consideration.

Virtual flow velocity [m / s] = (T [K] / T0 [K]) ^ (1/2)
× (Total stroke volume [m ³ ] × Volumetric efficiency when throttle valve is fully open
× (Engine speed [rpm] / 120))
/ Throttle valve opening area [m ² ]) (Appendix 7)
Where T [K]: intake air temperature,
T0 [K]: standard intake air temperature (298 K),
(Supplement 7) (T / T0) ^ (1/2) on the right side of the equation is a correction for a change in the sound speed accompanying a change in the intake air temperature. (Supplement 7) ^ on the right side of the equation represents a power.

  To use the characteristics shown in FIGS. 5 (a), 5 (b), 6 (a) and 6 (b), the characteristics are stored in a memory in the engine controller 10 as a table. Using the stored table, from the virtual flow velocity u ′ and the virtual Mach number M ′, normalized volume efficiency, throttle valve front-rear intake pressure ratio (P2 / P1), throttle valve front-rear intake density ratio (ρ2 / ρ1) Inversely, the virtual flow velocity u ′ or virtual Mach is calculated from any one of normalized volumetric efficiency, throttle valve front-rear intake pressure ratio (P2 / P1), and throttle valve front-rear intake density ratio (ρ2 / ρ1). The number M ′ may be calculated.

However, the calculation method is not limited to such a table search, and an arithmetic expression can also be used. To explain this, in Japanese Patent Laid-Open No. 2002-130039, the function Φ (P2 / P1) required for calculating the air flow rate passing through the throttle valve by an arithmetic expression is expressed as the throttle valve front-rear intake pressure ratio (P2 / P1). ) Is less than a predetermined value and exceeds a predetermined value, and is calculated by the following formula.
(1) When P2 / P1 ≦ 1 / (1 + κ) Φ (P2 / P1) = {κ / (2 (κ + 1))} 1/2 (Supplement 8)
(2) When P2 / P1> 1 / (1 + κ) Φ (P2 / P1) = [(κ−1) / 2κ × {(1-P2 / P1) + P2 / P1}
× (1-P2 / P1)] ^ 1/2 (Supplement 9)
Here, P1 is the intake pressure upstream of the throttle valve, P2 is the intake pressure downstream of the throttle valve, and κ is the specific heat ratio of the intake air. ^ Represents a power.

In relation to the present invention, the value obtained by dividing the function Φ (P2 / P1) of the equations (A8) and (A9) by the throttle valve front-rear intake pressure ratio (P2 / P1) and multiplying by the speed of sound c, Since this corresponds to the virtual flow velocity u ′ of the present invention, the virtual flow velocity u ′ of the present invention can be calculated by the following equation using the function Φ (P2 / P1) of the (complement 8) and (complement 9) equations. .
(3) When P2 / P1 ≦ 1 / (1 + κ) u ′ [m / s] = c [m / s] × (P1 / P2) × Φ (P2 / P1)
= C × (P1 / P2) × {κ / (2 (κ + 1))} ^ 1/2
... (Supplement 10)
(4) When P2 / P1> 1 / (1 + κ) u ′ [m / s] = c [m / s] × (P1 / P2) × Φ (P2 / P1)
= C × (P1 / P2) × [(κ−1) / 2κ
X {(1-P2 / P1) + P2 / P1}
× (1-P2 / P1)] ^ 1/2 (Supplement 11)
Here, c in (complement 10) and (complement 11) is the speed of sound.

When the above (complement 4) equation is used for these (complement 10) equation and (complement 11) equation, the virtual Mach number M ′ can also be calculated by the following equation.
(5) When P2 / P1 ≦ 1 / (1 + κ) M ′ [anonymous number] = u ′ [m / s] / c [m / s]
= (P1 / P2) × {κ / (2 (κ + 1))} ^ 1/2
... (Supplement 12)
(6) When P2 / P1> 1 / (1 + κ) M ′ [anonymous number] = u [m / s] / c [m / s]
= (P1 / P2) × [(κ−1) / 2κ
X {(1-P2 / P1) + P2 / P1}
× (1-P2 / P1)] ^ 1/2 (Supplement 13)
As a result, the (complement 10), (complement 11), (complement 12), and (complement 13) formulas calculate the virtual flow velocity u ′ and the virtual Mach number M ′ from the throttle valve front-rear intake pressure ratio (P2 / P1). This is an arithmetic expression for calculation. In addition, the throttle valve front / rear intake pressure ratio (ρ2 / ρ1) is substituted for the throttle valve front / rear intake pressure ratio (P2 / P1) in the (complement 10), (complement 11), (complement 12), and (complement 13) formulas. ) Or normalized volumetric efficiency.

  In this way, the virtual flow velocity u ′ and the virtual Mach number M ′ are calculated from any one of the throttle valve front / rear intake pressure ratio (P2 / P1), the throttle valve front / rear intake density ratio (ρ2 / ρ1), and the normalized volumetric efficiency. The operation formula for doing this was obtained.

  However, on the contrary, there is no arithmetic expression for obtaining the throttle valve front-rear intake pressure ratio (P2 / P1), the throttle valve front-rear intake density ratio (ρ2 / ρ1) or the normalized volumetric efficiency from the virtual flow velocity u ′ and the virtual Mach number M ′. Therefore, at this time, it is necessary to search using the tables having the contents shown in FIGS. 5 (a), 5 (b), 6 (a), and 6 (b).

  This completes the explanation of “normalized volumetric efficiency” and “virtual flow velocity” newly introduced in the present invention.

  Returning to FIG. 1, the throttle sensor 1 as the throttle valve opening detection means detects the actual throttle valve opening. Here, a so-called electronically controlled throttle device in which the throttle valve is driven by an actuator that receives a command (target throttle valve opening) from the engine controller 10 regardless of the accelerator pedal is targeted. In this electronically controlled throttle device, the throttle sensor 1 is used. The feedback control is performed so that the actual throttle valve opening detected by the above is matched with the target throttle valve opening. In the throttle sensor 1, the throttle valve opening is converted into a voltage such as a potentiometer and then converted into a throttle valve opening.

  The engine controller 10 to which a signal from the throttle sensor 1 is input together with a signal from the crank angle sensor (2, 3) has a function of a means 11 for calculating volumetric efficiency.

  The volumetric efficiency calculating means 11 includes a throttle valve opening area calculating means 12, a purge valve opening area calculating means 13, a total opening area calculating means 14, an engine speed calculating means 15, a throttle valve fully opening volumetric efficiency calculating means 16, a virtual flow velocity. Alternatively, it comprises a virtual Mach number calculating means 17, a normalized volume efficiency calculating means 18, and a multiplying means 19.

  First, the throttle valve opening area calculating means 12 calculates a throttle valve opening area Atvo by searching a predetermined table from the actual throttle valve opening detected by the accelerator sensor 1. An example of the contents of the table is shown in FIG. The characteristics of FIG. 2 are different from those of the butterfly type throttle valve. Thus, the present invention is intended not only for butterfly type throttle valves but also for those equipped with throttle valves other than butterfly type.

  The purge valve opening area calculating means 13 calculates a purge valve opening area Ap by searching a table having the contents shown in FIG. 3 from the purge valve duty ratio given to the purge valve, and the total opening area calculating means 14 calculates these throttle valve openings. The sum of the area Atvo and the purge valve opening area Ap is calculated as the total opening area A. The present invention is not only intended for an engine having a purge valve, but also for an engine not having a purge valve. That is, in an engine that does not include a purge valve, it is only necessary to set the purge valve opening area Ap = 0.

  The crank angle sensor includes a position sensor 2 and a phase sensor 3. The position sensor 2 is provided opposite to a signal plate attached to the crankshaft, and generates a signal (position signal) that rises every 10 ° of the crank angle. The phase sensor 3 is provided opposite to a signal plate attached to the camshaft, and generates a signal (phase signal) for performing cylinder discrimination. The engine speed calculation means 15 that receives these two signals, the position signal and the phase signal, performs predetermined signal processing to calculate the engine speed Ne. Although not shown, the engine controller 10 generates a reference position signal that serves as a base point of fuel injection timing and ignition timing from two signals of a position signal and a phase signal.

  The throttle valve fully open volumetric efficiency calculation means 16 searches the table having the contents shown in FIG. 4 from the engine speed Ne, thereby sucking the intake air downstream of the throttle valve 21 (downstream of the throat) into the pump (combustion chamber). Thus, the throttle valve fully open volumetric efficiency ηvwot representing the efficiency of sucking the intake air downstream of the throttle valve 21 into the pump when the throttle valve 21 is fully opened is calculated. The engine has a wide range of engine rotation speeds and is equipped with an intake pipe, so generally the amount of air that is drawn into the engine due to differences in operating conditions and environmental conditions due to static effects, dynamic effects, thermal effects, etc. The volumetric efficiency) varies greatly, but if it is limited to when the throttle valve is fully opened, a characteristic characteristic can be obtained for each engine speed. Therefore, the characteristic shown in FIG. 4 is obtained in advance by adaptation and stored in the memory in the engine controller 10. Let me. The characteristic of FIG. 4 shows an example. Although not shown, the volumetric efficiency ηvwot when the throttle valve is fully opened may exceed 1.0. That is, the characteristics shown in FIG. 4 are values determined by the engine specifications, and differ depending on the engine specifications.

  In the virtual flow velocity or virtual Mach number calculating means 17, the virtual flow velocity u ′ is calculated by the following equation based on the total opening area A, the engine rotational speed Ne, the throttle valve fully opened volumetric efficiency ηvwot, and the total engine stroke volume Vtotal. A virtual Mach number M ′ that is a value obtained by dividing “by the speed of sound c” is calculated.

u ′ [m / s] = (Vtotal [m ³ ] × ηvwot × (Ne [rpm] / 120))
/ A [m ² ] (1)
M ′ [anonymous number] = u ′ [m / s] / c [m / s]
= (Vtotal [m ³ ] × ηvwot × (Ne [rpm] / 120))
/ (A [m ² ] × c [m / s]) (2)
The reason why the engine speed Ne [rpm] is divided by 120 in the right side of the equation (1) is to obtain a value [/ s] per one stroke (two engine revolutions).

  Here, the virtual flow velocity u ′ in the above equation (1) and the virtual Mach number M ′ in the above equation (2) are physical quantities introduced for the first time in the present invention. Supplement 4) The description is given.

  The engine total stroke volume Vtotal on the right side of the above equation (1) is the total stroke volume (displacement) for all cylinders in a multi-cylinder engine. However, even in the case of a multi-cylinder engine, for example, when the intake system is completely independent for each bank in a V-type engine, or when a structure is adopted in which some cylinders are deactivated while the intake valve is closed. Set or calculate an effective volume. For example, in a V-type engine, the total stroke volume may be handled for each independent bank. In addition, in an engine that employs a structure in which some of the cylinders are deactivated while the intake valve is kept closed, different total stroke volumes may be prepared at the time of deactivation and other than at the time of deactivation. In the embodiment, it is considered for all cylinders, but may be considered for one cylinder.

  Further, since the flow velocity changes depending on the sound velocity, if the change is also taken into consideration, the virtual flow velocity u ′ and the virtual Mach number M ′ may be obtained by the following equations instead of the above equation (1).

u ′ [m / s] = (T / T0) ^ (1/2)
× (Vtotal [m ³ ] × ηvwot × (Ne [rpm] / 120))
/ A [m ² ]) (3a)
M ′ [anonymous number] = u ′ [m / s] / c [m / s]
= (T / T0) ^ (1/2)
× (Vtotal [m ³ ] × ηvwot × (Ne [rpm] / 120))
/ (A [m ² ] × c [m / s]) (3b)
Where T [K]: intake air temperature,
T0 [K]: standard intake air temperature (298 K),
(T / T0) ^ (1/2) on each right side of the equations (3a) and (3b) is a correction for the change in the sound speed accompanying the temperature change.

  The normalized volumetric efficiency calculation means 18 searches the table having the contents shown in FIG. 5A or FIG. 6A from the virtual flow velocity u ′ in the expressions (1) and (3a), or (2) Normalized volumetric efficiency is calculated by searching a table having the contents shown in FIG. 5B or FIG. 6B from the virtual Mach number M ′ in the equation or (3b).

  When the virtual flow velocity or virtual Mach number calculating means 17 uses the volume efficiency ηvwot when the throttle valve is fully opened, the normalized volume efficiency calculated by the normalized volume efficiency calculating means 18 is the value defined by the above (Supplement 2), that is, the volume Since the efficiency is a value obtained by dividing the efficiency by the volume efficiency ηvwot when the throttle valve is fully opened, the multiplication means 19 multiplies the normalized volume efficiency calculated by the normalized volume efficiency calculation means 18 by the volume efficiency ηvwot when the throttle valve is fully opened. Calculated as ηv.

  How to use the volumetric efficiency ηv thus determined for engine control will be described later with reference to tenth to sixteenth embodiments.

  Here, the operation and effect of the first embodiment will be described.

  According to the first embodiment (the invention described in claim 1), the engine speed Ne, the total stroke volume Vtotal, and the throttle valve fully opened volumetric efficiency ηvwot (the intake air from the downstream of the throttle valve 21 to the total stroke volume) The virtual flow velocity u ′ and the virtual Mach number M ′ are calculated by the above formulas (3a) and (3b) based on the volumetric efficiency) and the throttle valve opening area Atvo (throat area). Here, the numerators on the right side of the equations (3a) and (3b) represent the suction ability as a pump for sucking the intake air downstream of the throttle valve 21 (throat portion) into the combustion chamber.

  Then, the normalized volume is obtained by searching the table having the contents shown in FIGS. 5A, 5B, 6A, and 6B from the virtual flow velocity u ′ and the virtual Mach number M ′. Efficiency is calculated.

  In this case, the present inventor has confirmed through experiments that the relationship between the virtual flow velocity u ', the virtual Mach number M', and the normalized volume efficiency shows a high correlation with any general engine. Meaning that any general engine shows a high correlation means that the characteristics shown in FIG. 5 (a), FIG. 5 (b) or FIG. 6 (a) and FIG. 6 (b) are related to the engine model. This means that a common intake model for the engine can be newly constructed. For this reason, the engine development period can be significantly shortened by using this versatile intake model.

Moreover, volumetric efficiency when the throttle valve 21 is fully opened, and noticed that a volumetric efficiency substantially equal until the total stroke volume from the throttle valve 21 downstream, in the present embodiment form condition, the throttle 21 valve (throat Part) The volumetric efficiency ηvwot (efficiency of sucking air downstream of the throttle valve into the pump) when the throttle valve is fully opened is adopted as the volumetric efficiency representing the efficiency of sucking the downstream intake air into the pump. At this time, since the normalized volumetric efficiency is a value obtained by dividing the volumetric efficiency by the volumetric efficiency ηvwot when the throttle valve is fully opened, the volumetric efficiency ηvwot when the throttle valve is fully opened is set to the normalized volumetric efficiency obtained as described above. By dividing, the volume efficiency ηv can be calculated immediately.

  As described above, according to the present embodiment, in the system in which the intake air amount introduced into the combustion chamber of the engine is controlled depending on the change in the intake air flow velocity in the intake pipe, normalization with the virtual flow velocity or virtual Mach number is performed. By utilizing the relationship between the volumetric efficiency, the volumetric efficiency in the engine equilibrium state can be calculated with high accuracy.

  In the first embodiment, the normalized volumetric efficiency is calculated based on the virtual flow velocity u ′ or the virtual Mach number M ′. However, as shown in FIGS. 52A and 52B, the virtual flow velocity u is calculated. Based on 'or the virtual Mach number M', the throttle valve front / rear intake pressure ratio calculation means 231 and the throttle valve front / rear intake density ratio calculation means 232 determine the throttle valve front / rear intake pressure ratio (throat front / rear intake pressure ratio) and the throttle valve front / rear intake pressure. The density ratio (intake / ratio ratio before and after the throat portion) may be calculated.

  FIG. 8 shows a second embodiment that replaces FIG. 1 of the first embodiment. The same parts as those in FIG.

  In the first embodiment, the normalized volumetric efficiency is calculated from the virtual flow velocity u ′ or the virtual Mach number M ′. On the contrary, in the second embodiment, the target virtual flow velocity tu ′ or the target is calculated from the target normalized volumetric efficiency. The virtual Mach number tM ′ is calculated.

  The engine controller 10 includes an engine target torque calculator 35, a target charging efficiency calculator 36, a target volume efficiency calculator 37, an engine speed calculator 15, a throttle valve fully open volume efficiency calculator 16, and a target normalized volume efficiency calculator. Means 38, target virtual flow velocity or target virtual Mach number calculating means 39, target throttle valve opening area calculating means 40, purge valve opening area calculating means 13, target total opening area calculating means 41, and target throttle valve opening calculating means 42. .

  First, the engine target torque calculating means 35 calculates an engine target torque that is an engine output torque requested by the driver based on the accelerator operation amount detected by the accelerator sensor 31. The shaft torque required by the vehicle may be calculated based on the accelerator operation amount, and the engine target torque may be calculated in consideration of the vehicle speed and the gear ratio. Furthermore, in the case of a hybrid vehicle, since the required torque is distributed between the motor and the engine, the distributed amount may be set as the engine target torque. Also, when auxiliary equipment is added, the engine target torque is increased by that much.

  The target charging efficiency calculating means 36 calculates a target charging efficiency tηc by searching a map having the contents shown in FIG. 9 from the target torque and the engine speed Ne.

  The atmospheric state detection means 32 detects the atmospheric state, that is, the intake air temperature Ta and the atmospheric pressure Pa. Normally, as shown in FIG. 43, an intake air temperature sensor 33 attached to the intake passage 22 or an atmospheric pressure sensor 34 attached to a portion opened to the atmosphere is used. The atmospheric pressure may be simply in a standard state. In this case, volumetric efficiency = filling efficiency.

  The target volume efficiency calculation means 37 calculates a value obtained by converting the target filling efficiency tηc into volume efficiency as the target volume efficiency tηv.

  Here, since the volumetric efficiency is the efficiency when the engine total stroke volume Vtotal is satisfied by the intake air in the atmospheric state as shown in the above (Appendix 1-1), it is not a parameter representing the absolute amount of intake air. In order to convert from the charging efficiency, which is the efficiency when the engine total stroke volume Vtotal is satisfied with the intake air in the standard state, to the volumetric efficiency, it is only necessary to correct in the atmospheric state, so the target volumetric efficiency tηv is calculated by the following equation.

tηv = (P0 / Pa) × (Ta / T0) × tηc (4)
However, P0: intake pressure (absolute pressure) in the standard state,
T0: Standard intake air temperature (absolute temperature),
Pa: atmospheric intake pressure (absolute pressure),
Ta: Intake air temperature (absolute temperature) in the atmospheric state,
Here, the intake pressure in the standard state is 99 kPa in absolute pressure, and the intake temperature in the standard state is 298 K in absolute temperature.

  The target normalized volume efficiency calculation means 38 calculates the target normalized volume efficiency by the following equation.

Target normalized volumetric efficiency = tηv / ηvwot (5)
That is, the target normalized volume efficiency is a value obtained by dividing the target volume efficiency tηv (target value of volume efficiency) by the volume efficiency ηvwot when the throttle valve is fully opened.

  In the target virtual flow velocity or target virtual Mach number calculating means 39, the target virtual flow velocity which is the target value of the virtual flow velocity is searched by searching the table having the contents shown in FIG. 5A or 6A from the target normalized volume efficiency. The target virtual Mach number tM ′, which is the target value of the virtual Mach number, is calculated by searching a table having the contents of FIG. 5B or FIG. 6B from tu ′ or the target normalized volume efficiency.

  The target throttle valve opening area calculating means 40 (target throat portion area calculating means) is based on the following equation based on the target virtual flow velocity tu ′, the throttle valve fully opened volume efficiency ηvwot, the engine speed Ne, and the total stroke volume Vtotal. Based on the target throttle valve opening area tAtvo (target throat portion area), or the target virtual Mach number tM ′, the sound speed c, the throttle valve fully open volume efficiency ηvwot, the engine speed Ne, and the total stroke volume Vtotal. A target throttle valve opening area tAtvo (target throat area) is calculated by the following equation.

tAtvo [m ² ] = (Vtotal [m ³ ] × ηvwot × (Ne [rpm] / 120))
/ Tu '[m / s]) (6)
tAtvo [m ² ] = (Vtotal [m ³ ] × ηvwot × (Ne [rpm] / 120))
/ (TM ′ × c [m / s]) (7)
The above expression (6) is an expression obtained by modifying the above expression (1), and the above expression (7) is an expression obtained by modifying the above expression (2).

  The target total opening area calculating means 41 calculates the sum of the target throttle valve opening area tAtvo and the purge valve opening area Ap as the target total opening area tA. Of course, when the purge valve is not open, the purge valve opening area Ap = 0, and the target total opening area tA coincides with the target throttle valve opening area tAtvo.

  The target throttle valve opening calculation means 42 calculates a target throttle valve opening by searching a table having the contents shown in FIG. 2 from the target total opening area tA.

  The throttle valve control means 43 controls the throttle valve actuator so that the actual throttle valve opening detected by the throttle sensor 1 coincides with the target throttle valve opening.

According to the second embodiment shaped state, calculates a target normalized volumetric efficiency from the target volumetric efficiency tηv the throttle valve fully open when the volumetric efficiency Itavwot, 5 from the target normalized volumetric efficiency (a), 5 (b) Alternatively, the target virtual flow velocity tu ′ and the target virtual Mach number tM ′ are calculated by searching a table having the contents shown in FIGS. 6A and 6B, and the target virtual flow velocity tu ′ and the target virtual Mach number tM are calculated. Based on ', the target throttle valve opening area tAtvo (target throat portion area) is calculated by the above-described equations (6) and (7). Here, the numerators on the right side of the above formulas (6) and (7) represent the suction ability as a pump for sucking the intake air downstream of the throttle valve 21 (throat portion) into the combustion chamber.

  In this case, the relationship between the target normalized volume efficiency, the target virtual flow velocity tu ′, and the target virtual Mach number tM ′ is the same even if “target” is attached. That is, the present inventor confirmed by experiments that the relationship between the target normalized volume efficiency and the target virtual flow velocity tu ′ and the target virtual Mach number tM ′ shows a high correlation for any general engine. Yes. Meaning that any general engine shows a high correlation means that the characteristics shown in FIG. 5 (a), FIG. 5 (b) or FIG. 6 (a) and FIG. 6 (b) are related to the engine model. This means that the engine can be used in common, and this makes it possible to build a new engine intake model with versatility. For this reason, the engine development period can be significantly shortened by using this versatile intake model.

Further, focusing on the fact that the volumetric efficiency when the throttle valve 21 is fully open is substantially equal to the volumetric efficiency from the downstream of the throttle valve 21 to the total stroke volume, in this embodiment, the throttle 21 valve (throat portion). The volumetric efficiency ηvwot when the throttle valve is fully open is adopted as the volumetric efficiency representing the efficiency of sucking the downstream intake air into the pump. At this time, the target normalized volumetric efficiency is a value obtained by dividing the target volumetric efficiency tηv, which is the target value of volumetric efficiency, by the volumetric efficiency ηvwot when throttle valve is fully opened (efficiency of sucking air downstream of the throttle valve into the pump). volumetric efficiency tηv Ru can immediately calculates a target normalized volumetric efficiency by dividing the throttle valve fully open when volumetric efficiency ηvwot a.

  As described above, according to the second embodiment, in the system in which the intake air amount introduced into the combustion chamber of the engine is controlled depending on the change in the intake air flow velocity in the intake pipe, the target virtual flow velocity tu ′ or the target virtual Mach By utilizing the relationship between the number tM ′ and the target normalized volumetric efficiency, the target throttle valve opening area tAtvo can be calculated with high accuracy.

  In the second embodiment, the target normalized volume efficiency is calculated, and the target virtual flow velocity tu ′ or the target virtual Mach number tM ′ is calculated based on the target normalized volume efficiency. FIG. 53 (a), ( As shown in b), instead of the target normalized volumetric efficiency, the target throttle valve front / rear intake pressure ratio calculation means 241 and the target throttle valve front / rear intake density ratio calculation means 242 are replaced by the target throttle valve front / rear intake pressure ratio (before / after the target throat portion). Intake pressure ratio) and target throttle valve front-rear intake density ratio (target throat front-rear intake density ratio) are calculated, and based on these target throttle valve front-rear intake pressure ratio and target throttle valve front-rear intake density ratio, the target virtual flow velocity tu ′ or The target virtual Mach number tM ′ may be calculated.

  In the second embodiment, the throttle valve opening area (throat) when the suction capacity (Vtotal × volume efficiency × Ne / 120) as a pump is made constant based on the target virtual flow velocity tu ′ or the target virtual Mach number tM ′. The target throttle valve opening area tAtvo (target throat part area), which is the target value of the part area), has been described, but as shown in FIG. 53 (c), the target virtual flow velocity tu ′ or the target virtual Mach number tM Based on ', the target suction capacity which is the target value of the suction capacity (Vtotal x volume efficiency x Ne / 120) as a pump when the target suction capacity calculation means 243 makes the throttle valve opening area (throat area) constant. May be calculated. The calculated target suction capacity can be obtained as a volume efficiency by dividing this by the total stroke volume Vtotal and Ne / 120.

Further, as shown in FIG. 53 (d), when the target suction capacity calculation means 243 is the target engine speed calculation means 244 for calculating the target engine speed, that is, when the target suction capacity is the target engine speed. engine speed control means 245, the actual rotational speed Ne is not such may be configured to control the engine rotational speed to coincide with the target engine rotational speed.

  FIG. 10 shows a third embodiment that replaces the throttle valve fully opened volumetric efficiency calculating means 16 in FIG. 1 of the first embodiment. The same parts as those in FIG.

  The third embodiment is premised on the provision of a variable valve timing mechanism (VTC mechanism) 50 that can variably control the intake valve cam phase (intake valve opening / closing timing). In an engine equipped with the VTC mechanism 50, the intake valve cam phase changes, and the volume efficiency ηvwot when the throttle valve is fully opened changes under the influence. Accordingly, the volume efficiency when the first normalized throttle valve is fully opened is calculated based on the actual intake cam phase, and the volume efficiency when the first normalized throttle valve is fully opened is used instead of the volume efficiency ηvwot when the throttle valve is fully opened.

  More specifically, the throttle valve fully open volumetric efficiency calculating means 16 includes an intake cam phase detecting means 52, an optimal intake cam phase calculating means 53, an intake cam phase offset angle calculating means 54, and a normalized throttle valve fully opening volumetric efficiency calculation. Means 55, intake system average temperature detection means 56, intake pulsation correction coefficient calculation means 57, and first normalized throttle valve fully open volumetric efficiency calculation means 58.

  First, the intake cam phase detection means 52 detects the actual intake cam phase based on the position signal from the position sensor 2 and the phase signal from the phase sensor 3. As the actual intake valve cam phase, for example, an intake valve closing timing or an intake valve opening timing may be used.

  The optimum intake cam phase calculating means 53 calculates the optimum intake cam phase (the intake cam phase when the intake amount is maximized) by searching a table having the contents shown in FIG. 11 from the engine speed Ne. It is known that the optimum intake cam phase varies greatly depending on the engine speed Ne. Therefore, as shown in FIG. 11, it is possible to obtain this by storing and setting the optimum intake cam phase in advance for each engine speed Ne.

  The intake cam phase offset angle calculation means 54 calculates the difference between the actual intake cam phase and the optimum intake cam phase as the intake cam phase offset angle. For example, if the x mark in FIG. 12 is the actual intake cam phase, the intake cam phase offset angle has the value shown in the figure. Since the actual intake cam phase comes to either the advance side or the retard side of the optimum intake cam phase, the offset angle may be obtained using the optimum intake cam phase as a base point.

  The normalized throttle valve fully opened volumetric efficiency calculating means 55 calculates the normalized throttle valve fully opened volumetric efficiency by searching a table having the contents shown in FIG. 13 from the intake cam phase offset angle.

  When the change in the intake air amount when the intake cam phase is changed is normalized, a substantially quadratic curve convex upward is drawn as shown in FIG. 13 with respect to the intake cam offset angle. This characteristic shown in FIG. 13 is stored as a table in a memory provided in the engine controller 10 to correct a change in intake air amount due to a difference in intake cam phase.

  In FIG. 13, there is an engine which generally has a left-right asymmetric characteristic, but as shown in FIG. Further, only one of the left and right characteristics may be stored in a memory provided in the engine controller 10 as a table. In this case, memory is saved.

  Here, “normalization” used for the volumetric efficiency when the throttle valve is fully opened is defined as 1.0 when the optimum intake cam phase is present, and less than 1.0 when the intake cam phase deviates therefrom. Means. In other words, the “normalization” used for the volumetric efficiency when the throttle valve is fully open is determined so that the volumetric efficiency when the throttle valve is fully open is 1.0 in the reference state. In the third embodiment, the optimum cam phase is the reference state. On the other hand, as for the volume efficiency when the throttle valve is fully opened introduced in the first embodiment, the reference state is not defined as shown in FIG.

  If the VTC mechanism 50 and the engine specifications are not so different, the characteristics shown in FIG. 13 can be used in common regardless of the engine model.

  The intake system average temperature detecting means 56 detects the intake system average temperature Tave. The intake system average temperature Tave varies with the temperature of the engine wall (intake port, combustion chamber) with reference to the intake air temperature. As shown in FIG. 14, the larger the difference ΔT between the intake air temperature Ta and the engine wall representative temperature, the greater the amount of heat exchanged with the intake air, and the greater the difference from the intake air temperature Ta. Therefore, the temperature difference ΔT (= Tw−Ta) is obtained by subtracting the intake air temperature Ta detected by the intake air temperature sensor 33 from the cooling water temperature Tw (engine wall representative temperature) detected by the water temperature sensor 51, and from this temperature difference ΔT. The intake air temperature change ΔTa is obtained by searching a table having the contents shown in FIG. 14, and a value obtained by adding the obtained intake air temperature change ΔTa to the intake air temperature Ta is calculated as the intake system average temperature Tave. For example, when the coolant temperature Tw becomes higher than the intake air temperature Ta due to the completion of warming up of the engine, the intake air temperature change ΔTa becomes positive in FIG. 14, and the value obtained by adding the positive air ΔTa to the intake air temperature Ta becomes the intake system average temperature Tave. .

  In the intake pulsation correction coefficient calculating means 57, the normal speed is calculated based on the engine rotational speed Ne, the intake system average temperature Tave, and the virtual flow velocity u ′ calculated in the first embodiment (or the flow velocity calculated in the twelfth embodiment). The intake pulsation correction coefficient for the volumetric efficiency when the throttle valve is fully opened is calculated.

  Under the intake pulsation, as shown in FIG. 15, the approximately second-order relationship between the intake cam offset angle and the normalized throttle valve fully opened volumetric efficiency changes greatly, and the normalized throttle valve fully opened volumetric efficiency does not depend on the intake cam offset angle. Take almost constant value (see solid line). On the other hand, the characteristics of the alternate long and short dash line are characteristics when there is no intake pulsation. Therefore, an intake pulsation correction coefficient is introduced in the vicinity of the resonance frequency f0 of the intake pulsation in order to reduce the degree of reflecting the normalized throttle valve fully opened volumetric efficiency to the first normalized throttle valve fully opened volumetric efficiency. The range in which the intake pulsation correction coefficient is introduced is between predetermined frequencies f1 and f2 with the resonance frequency f0 substantially at the center as shown in FIGS.

  The resonance frequency f0 can be easily obtained by the following equation (Helmholtz resonance equation).

f0 [Hz] = (c [m / s] / 2π)
× {(Intake pipe cross-sectional area [m ² ] / Intake system volume [m ² ])
× Intake system length [m]} ^ (1/2) (8)
The sound speed c in the equation (8) is calculated from the sound speed c0 in the standard state, the intake system average temperature Tave, and the intake air temperature T0 in the standard state according to the following equation.

c [m / s] = c0 × (Tave [K] / T0 [K]) ^ (1/2) (9)
However, c0 [m / s]: 332 m / s
T0 [K]: 298K
If there is a higher-order resonance of the same system or a resonance system with another structure, a plurality of resonance frequencies may be set.

  In summary, the sound speed c is calculated from the intake system average temperature Tave by the expression (9), the resonance frequency f0 is calculated from the sound speed c by the expression (8), and a predetermined width is provided with respect to the resonance frequency f0. A first frequency f1 [Hz] and a second frequency f2 [Hz] are set. Here, since there is a relationship of f [Hz] = (Ne [rpm] / 120) × the number of cylinders between the frequency f and the engine rotational speed Ne, f1 and f2 are the same units as the rotational speed Ne by the following equation. Convert to [rpm].

f1N [rpm] = f1 × (120 / number of cylinders)
f2N [rpm] = f2 × (120 / number of cylinders)
When f1N <Ne <f2N and approximately 90 m / s (Mach number 0.2 to 0.3) ≧ virtual flow velocity (or flow velocity) ≧ intake pulsation correction coefficient = 0, otherwise, intake pulsation Correction coefficient = 1. Therefore, the characteristics of the intake pulsation correction coefficient are as shown in FIG.

  Here, the condition of about 90 m / s ≧ virtual flow velocity (or flow velocity) is to limit the region where intake pulsation occurs. In other words, when approximately 90 m / s <virtual flow velocity (or flow velocity), the intake pulsation disappears and resonance does not occur, so there is no need to correct even if f1N <Ne <f2N (intake pulsation correction coefficient = 1).

  The first normalized throttle valve fully opened volumetric efficiency calculating means 58 calculates the first normalized throttle valve fully opened volumetric efficiency by the following equation using the normalized throttle valve fully opened volumetric efficiency and the intake pulsation correction coefficient. .

Volume efficiency when the first normalized throttle valve is fully open
= 1- (1-normalized throttle valve fully open volumetric efficiency) x intake pulsation correction coefficient
(10)
When the equation (10) is specifically calculated, since the intake pulsation correction coefficient = 0 in the region where the intake pulsation occurs, the volume efficiency when the first normalized throttle valve is fully opened = 1. In the region where no intake pulsation occurs, the first normalized throttle valve fully open volumetric efficiency = the normalized throttle valve fully open volumetric efficiency.

  The first normalized throttle valve fully opened volumetric efficiency calculated in this way is used instead of the throttle valve fully opened volumetric efficiency ηvwot of the first embodiment.

  The reason why “first” is added before the volumetric efficiency when the throttle valve is fully opened is to distinguish the volumetric efficiency when the throttle valve is fully opened in the embodiments described later.

In this way, according to the third embodiment shaped state, to detect the actual intake cam phase, and calculates an optimum intake cam phase in accordance with the engine rotational speed Ne, the intake cam phase offset from the actual intake cam phase and the optimal intake cam phase An angle is calculated, and the normalized throttle fully open volumetric efficiency is calculated based on the intake cam phase offset angle, and the intake pulsation correction coefficient is calculated based on the engine speed Ne, the intake system average temperature Tave, and the virtual flow velocity or flow velocity. A value obtained by multiplying the normalized pulsation throttle valve fully open volume efficiency by the intake pulsation correction coefficient is calculated as a first normalized throttle valve fully opened volumetric efficiency, and the first normalized throttle valve fully opened volumetric efficiency is calculated. Since it is used instead of the volumetric efficiency ηvwot when the throttle valve is fully open, the change in the volumetric efficiency when the throttle valve is fully open due to the difference in intake cam phase and the presence or absence of intake pulsation is corrected. -Normalized throttle valve fully open when the volumetric efficiency can be obtained with good accuracy.

In the third embodiment, the actual intake cam phase is detected, the normalized throttle valve fully open volumetric efficiency is calculated based on the actual intake cam phase, and the normalized throttle valve fully open volumetric efficiency is calculated as the throttle valve fully open. Although the case where the hourly volume efficiency ηvwot is used instead is described, the present invention is not limited to this. For example, in an engine having an intake cam phase control means for calculating a target intake cam phase and controlling the actual intake cam phase so as to coincide with the target intake cam phase, a normalized throttle valve based on the target intake cam phase calculating the fully open time volumetric efficiency, have good be used in place of the normalized throttle valve fully open when the volumetric efficiency in the throttle valve fully open when the volumetric efficiency.

  19 is a fourth embodiment, FIG. 20 is a fifth embodiment, FIG. 22 is a sixth embodiment, FIG. 24 is a seventh embodiment, FIG. 26 is an eighth embodiment, FIG. 29 is a ninth embodiment, 1 is replaced with the volume efficiency calculating means 16 when the throttle valve is fully opened in FIG.

Here, the “normalization” used for the volumetric efficiency when the throttle valve is fully opened is also used in the fourth to ninth embodiments. That is, when the target EGR rate Megr is zero in the fourth embodiment shown in FIG. 19, and when the temperature difference ΔT between the cooling water temperature Tw and the intake air temperature Ta is zero in the fifth embodiment shown in FIG. In the sixth embodiment, when the cooling water temperature Tw is 80 ° C., which is the reference temperature, and in the seventh embodiment shown in FIG. 24, when the target equivalent ratio TFBYA is 1.0 (when the target air-fuel ratio is the stoichiometric air-fuel ratio), FIG. In the eighth embodiment shown in FIG. 29, the intake control valve is in the closed state, and in the ninth embodiment shown in FIG. 29, the time when the turbocharger 111 is not working is the reference state. Volume efficiency of the second normalized throttle valve fully opened in the embodiment, Volume efficiency of the third normalized throttle valve fully opened in the fifth embodiment, Volume efficiency of the fourth normalized throttle valve fully opened in the sixth embodiment, Seventh embodiment 5th normalized slot Torr valve fully open when the volumetric efficiency, sixth normalized throttle valve fully open when the volumetric efficiency of the eighth embodiment, the seventh normalized throttle valve fully open when the volumetric efficiency of the ninth embodiment becomes 1.0, respectively,
The fourth embodiment shown in FIG. 19 is premised on the provision of an EGR device. The EGR device includes an EGR passage 24 that communicates the intake passage 22 and the exhaust passage 23, an EGR valve 25 that can variably adjust the opening area of the EGR passage 24, and an actuator 26 that drives the EGR valve 25. In an engine equipped with such an EGR device, when EGR gas is introduced into the intake passage 22, the volumetric efficiency when the throttle valve is fully opened changes under the influence. Therefore, the volumetric efficiency when the normalized throttle valve is fully opened is calculated based on the target EGR rate. Specifically, normalized volumetric efficiency when the target EGR rate is zero is introduced when the throttle valve is fully opened. That is, when the EGR is activated, the volumetric efficiency when the throttle valve is fully opened is calculated to be reduced by the amount of introduction of the EGR gas corresponding to the target EGR rate.

  In FIG. 19, the throttle valve fully open volumetric efficiency calculating means 16 includes a target EGR rate calculating means 61 and a second normalized throttle fully open volumetric efficiency calculating means 62.

  The target EGR rate calculation means 61 calculates the target EGR rate Megr according to the operating conditions (engine load and rotational speed Ne). The actual EGR rate estimated from the opening degree of the EGR valve 25 may be used instead of the target EGR rate Megr.

  The second normalized throttle fully opened volumetric efficiency calculating means 62 calculates a value of 1-Megr as the second normalized throttle fully opened volumetric efficiency. That is, the volume efficiency when the second normalized throttle valve is fully opened is 1.0 when the target EGR rate Megr is zero, and is a value that becomes smaller than 1.0 as the target EGR rate Megr increases.

  The second normalized throttle valve fully open volumetric efficiency calculated in this way is used instead of the throttle valve fully open volumetric efficiency ηvwot of the first embodiment.

According to the fourth embodiment forms state, calculates a target EGR rate Megr, calculates a second normalized throttle valve fully open when volumetric efficiency on the basis of the target EGR rate Megr, the second normalization throttle valve fully open when the volumetric efficiency Is used instead of the volumetric efficiency ηvwot when the throttle valve is fully open, the change in the volumetric efficiency when the throttle valve is fully opened due to the introduction of EGR gas can be corrected to accurately determine the volumetric efficiency when the throttle valve is fully open.

  Although the EGR valve 25 as the external EGR device has been described in the fourth embodiment, the EGR method is not limited to this, and there is an engine including an internal EGR device. For example, in the case where a VTC mechanism is provided for the exhaust valve, the amount of burnt gas remaining in the combustion chamber, that is, the EGR rate can be variably controlled by changing the exhaust cam phase (exhaust valve opening / closing timing, etc.). The VTC mechanism for the exhaust valve functions as an internal EGR device. The fourth embodiment can also be applied to an engine including such an internal EGR device. That is, in the case of an engine equipped with an internal EGR device, the target value or actual value of the internal EGR rate may be used instead of the target EGR rate Megr.

  In the fifth embodiment shown in FIG. 20, the third normalized throttle valve fully open volumetric efficiency calculating means 71 as the throttle valve fully open volumetric efficiency calculating means 16 uses the cooling water temperature Tw from the water temperature sensor 51 to determine from the intake air temperature sensor 33. The value obtained by subtracting the intake air temperature Ta is calculated as a temperature difference ΔT (= Tw−Ta), and the volume efficiency when the third normalized throttle valve is fully opened is calculated from this temperature difference ΔT by searching a table having the contents shown in FIG. To do. As shown in FIG. 21, the volume efficiency when the third normalized throttle valve is fully opened becomes 1.0 when the temperature difference ΔT is zero, and becomes smaller than 1.0 as the temperature difference ΔT becomes a positive value. For example, when the temperature difference ΔT is positive, that is, when the cooling water temperature Tw is higher than the intake air temperature Ta, the intake air rises by receiving heat from the cooling water, and at this time, the volumetric efficiency when the throttle valve is fully opened decreases. ing. An example where the temperature difference ΔT is negative is immediately after the vehicle is put in a cold garage in a warm garage. The coolant temperature Tw is the engine wall representative temperature, and may be the engine oil temperature instead. The characteristics shown in FIG. 21 must be adapted to each engine model.

Although the intake air temperature Ta from the cooling water temperature Tw throttle valve fully open when the volumetric efficiency at a pressure drop due to the decrease in the intake air density decreases the intake air density when (the engine walls representative temperature) is high is being lowered, according to the fifth form status For example, the coolant temperature Tw (engine wall representative temperature) and the intake air temperature Ta are detected, and the volume efficiency when the third normalized throttle valve is fully opened is calculated based on the temperature difference ΔT that is the value obtained by subtracting the intake air temperature Ta from the coolant temperature Tw. Since the third normalized throttle valve fully open volumetric efficiency is used in place of the throttle valve fully open volumetric efficiency ηvwot, even when the coolant temperature Tw is higher than the intake air temperature Ta, the change in the volumetric efficiency when the throttle valve is fully open is corrected. Thus, the volumetric efficiency when the normalized throttle valve is fully opened can be obtained with high accuracy.

  In the sixth embodiment shown in FIG. 22, the fourth normalized throttle valve fully open volumetric efficiency calculating means 81 as the throttle valve fully open volumetric efficiency calculating means 16 includes FIG. 23 based on the cooling water temperature Tw from the water temperature sensor 51. The volume efficiency at the time when the fourth normalized throttle valve is fully opened is calculated by searching the table to be executed. As shown in FIG. 23, the volume efficiency when the fourth normalized throttle valve is fully opened is 1.0 when the cooling water temperature Tw is 80 ° C., and becomes a value smaller than 1.0 as the cooling water temperature Tw becomes higher than 80 ° C. In FIG. 23, 80 ° C. is the warm-up completion temperature (reference temperature). The characteristic diagram of FIG. 23 shows that the intake air rises by receiving heat from the cooling water at 80 ° C. or higher, and at this time the volumetric efficiency when the throttle valve is fully opened decreases. Note that 80 ° C. is merely an example, and the characteristics shown in FIG. 23 need to be adapted to each engine model.

According to the sixth form state, the fourth calculating the normalized throttle valve fully open when volumetric efficiency based on the coolant temperature Tw (engine walls representative temperature), the throttle valve fully opened the fourth normalized throttle valve fully open when the volumetric efficiency Since it is used instead of the hourly volume efficiency ηvwot, the same effect as the fifth embodiment can be obtained. The sixth embodiment is a simplified version of the fifth embodiment, and even if the normalized throttle valve fully opened volumetric efficiency is calculated depending on only the cooling water temperature Tw as in the sixth embodiment, a certain degree of accuracy is achieved. Obtainable.

  In the seventh embodiment shown in FIG. 24, the fifth normalized throttle valve fully open volumetric efficiency calculating means 91 as the throttle valve fully open volumetric efficiency calculating means 16 includes FIG. 25 from the target equivalent ratio TFBYA (target air-fuel ratio). The volume efficiency when the fifth normalized throttle valve is fully opened is calculated by searching the table. As shown in FIG. 25, the volume efficiency when the fifth normalized throttle valve is fully opened is 1.0 when the target equivalent ratio TFBYA is 1.0, and the target is in the region where the target equivalent ratio TFBYA exceeds 1.0 (rich region). The larger the equivalent ratio TFBYA is, the larger the value exceeds 1.0. On the contrary, in the region where the target equivalent ratio TFBYA is less than 1.0 (lean region), the value becomes smaller than 1.0 as the target equivalent ratio TFBYA decreases. .

  In FIG. 25, the volumetric efficiency when the normalized throttle valve is fully open exceeds 1.0 in the rich region when there is more fuel than the stoichiometric air-fuel ratio fuel as in the rich region (see FIG. 43). This is because the cooling effect due to the vaporization of the injected fuel spray increases and the volumetric efficiency when the throttle valve is fully opened increases. The characteristics shown in FIG. 25 can be used in common regardless of the engine specifications as long as they do not greatly differ from the specifications of the fuel type, the fuel injection valve 29 and the intake port shape.

  The target equivalent ratio TFBYA is a value calculated when calculating the fuel injection pulse width Ti as described later in the thirteenth embodiment.

When fuel is vaporized, it takes heat of vaporization and cools the intake valve and the intake air itself. That is, fuel is higher cooling effect is enhanced throttle valve fully open when the volumetric efficiency often is to increase, according to the seventh type state, fifth normalized throttle based on the target equivalent ratio TFBYA representing the abundance of fuel The volume efficiency when the valve is fully open is calculated, and the volume efficiency when the fifth normalized throttle valve is fully opened is used instead of the volume efficiency ηvwot when the throttle valve is fully open. The volumetric efficiency when the throttle valve is fully opened can be accurately obtained by correcting the change in the volumetric efficiency when the throttle valve is fully opened.

In the seventh embodiment has been described in the target equivalent ratio TFBYA (target air-fuel ratio), has such may the target equivalent ratio the actual equivalence ratio in place of TFBYA even (actual air-fuel ratio). The actual equivalent ratio here is the following value. An engine that is switched from a stoichiometric air-fuel ratio (at this time, the target equivalent ratio is 1.0) to a lean air-fuel ratio (at this time, the target equivalent ratio is less than 1.0) in a predetermined operating range in order to improve fuel efficiency. There is. If the air-fuel ratio is switched stepwise when switching the lean air-fuel ratio from the stoichiometric air-fuel ratio or vice versa, a driving shock may occur, so the air-fuel ratio is switched slowly by performing ramp processing etc. . In this case, the value obtained by performing the ramp process with respect to the target equivalent ratio is the actual equivalent ratio.

  In the eighth embodiment shown in FIG. 26, the sixth normalized throttle valve fully open volumetric efficiency calculating means 91 that receives the open / close command value for the intake control valve (variable intake device) is the open command value for the intake control valve. The sixth normalized throttle valve fully open volumetric efficiency is calculated by searching a table having the contents shown in FIG. 28 from the engine speed Ne. As shown in FIG. 28, the volume efficiency when the sixth normalized throttle valve is fully open is 1.0 when the intake control valve is in the closed state (reference state), and the engine speed Ne when the intake control valve is in the open state. Depending on the value, the value is larger than 1.0 or smaller than 1.0.

  The intake control valve functions as a variable intake device that can variably control the intake pipe length from the intake pipe assembly to the intake port. FIG. 27 shows an example of the intake control valve 102 for a 6-cylinder engine. When the intake control valve 102 is closed, the intake pipe length from the intake pipe collecting portion 103 to the intake port 104 becomes longer, and the medium / low speed torque is enriched. On the other hand, when the intake control valve 102 is opened, the intake pipe length is shortened and the high-speed torque becomes rich.

 Since there are various types of variable intake devices such as the one that expands and contracts the intake port length itself, the characteristics shown in FIG. 28 are adapted to each engine model according to the variable intake device provided in the engine.

Although there is possible to improve the volumetric efficiency by changing the intake pipe length of the intake port to the intake pipe collecting portion by the intake control valve in a multi-cylinder engine, according to the eighth embodiment-shaped state, to the intake control valve Based on the opening / closing command value, the volume efficiency when the sixth normalized throttle valve is fully opened is calculated, and the volume efficiency when the sixth normalized throttle valve is fully opened is used in place of the volume efficiency ηvwot when the throttle valve is fully opened. Even when the intake pipe length from the intake section to the intake port is variably controlled, the volumetric efficiency when the throttle valve is fully open can be accurately determined by correcting the change in the volumetric efficiency when the throttle valve is fully open.

  The ninth embodiment shown in FIG. 29 is based on an engine including a turbocharger 111. In an engine including the turbocharger 111, the volumetric efficiency when the throttle valve is fully opened increases when the turbocharger 111 operates. Therefore, the normalized throttle valve fully open volumetric efficiency is calculated based on the actual boost pressure, and this normalized throttle valve fully open volumetric efficiency is used instead of the throttle valve fully open volumetric efficiency ηvwot. Specifically, the supercharging pressure sensor 112 as supercharging pressure detection means is installed around the collector 27 and detects the upstream pressure (that is, supercharging pressure) of the throttle valve 21. If the signal of the supercharging pressure sensor 112 is used as it is, it will be affected by pressure pulsation, so that a smoothing process is added to the signal of the supercharging pressure sensor 112. The supercharger is not limited to the turbocharger 111 but may be a mechanical supercharger.

  In the seventh normalized throttle fully opened volumetric efficiency calculating means 113 to which the supercharging pressure detected by the supercharging pressure sensor 112 and the atmospheric pressure Pa detected by the atmospheric pressure sensor 34 are inputted, the supercharging pressure is set to the atmospheric pressure Pa. The value divided by (supercharging pressure / Pa) is calculated as the volume efficiency when the seventh normalized throttle valve is fully opened. The volume efficiency when the seventh normalized throttle valve is fully opened becomes 1.0 when the turbocharger 111 is not operating (the supercharging pressure is equal to the atmospheric pressure), and the turbocharging device 111 is activated and the supercharging pressure is reached. Is a value that becomes larger than 1.0 as the pressure becomes higher than the atmospheric pressure Pa.

  Since the atmospheric pressure sensor 34 is provided in order to consider a case where the atmospheric pressure is outside the standard atmospheric pressure, the atmospheric pressure may be set to the standard atmospheric pressure if the standard atmospheric pressure is acceptable (in this case, the atmospheric pressure is the atmospheric pressure). Barometric pressure sensor 34 is unnecessary).

According to a ninth embodiment shaped state, with the turbocharger 111, and detects the actual boost pressure to calculate the ratio of the supercharging pressure and the atmospheric pressure as the seventh normalized throttle valve fully open when the volumetric efficiency, Since this sixth normalized throttle valve fully open volumetric efficiency is used in place of the throttle valve fully open volumetric efficiency ηvwot, even when the volumetric efficiency when the throttle valve is fully open increases significantly due to pressure increase due to supercharging, the throttle valve fully open It is possible to accurately obtain the volumetric efficiency when the normalized throttle valve is fully opened by correcting the change in hourly volumetric efficiency.

  When the standard value is used as the atmospheric pressure, substantially the same effect can be exhibited without using an expensive atmospheric pressure sensor.

In the ninth embodiment, the normalized throttle valve fully opened volumetric efficiency is calculated based on the actual boost pressure, and this normalized throttle valve fully opened volumetric efficiency is used instead of the throttle valve fully opened volumetric efficiency ηvwot. As described above, in an engine having a supercharging pressure control means for calculating a target supercharging pressure and controlling the supercharging pressure so that the actual supercharging pressure coincides with the target supercharging pressure, the target supercharging pressure is reduced to the target supercharging pressure. based calculates the normalized throttle valve fully open when volumetric efficiency, yet such may also be the normalized throttle valve fully open when the volumetric efficiency as used in place of the throttle valve fully open when volumetric efficiency Itavwot.

  30 shows the tenth embodiment, FIG. 36 shows the eleventh embodiment, FIG. 41 shows the twelfth embodiment, FIG. 43 shows the thirteenth embodiment, FIG. 44 shows the fourteenth embodiment, and FIG. 46 shows the fifteenth embodiment. In the six embodiments, the volume efficiency ηv calculated by the volume efficiency calculation means 11 of the first embodiment shown in FIG. 1 is used to diagnose engine components (EGR valve 25 and air flow meter 141) and to perform engine control (fuel injection amount). Used for the control of

  First, the tenth embodiment shown in FIG. 30 is based on the volumetric efficiency ηv calculated by the volumetric efficiency calculating means 11 of the first embodiment on the premise of an engine equipped with an EGR valve 25 (EGR device). It is diagnosed whether or not the valve 25 has a closed failure. The same parts as those in FIG. 1 of the first embodiment and FIG. 19 of the fourth embodiment are denoted by the same reference numerals.

  Specifically, in FIG. 30, the engine controller 10 includes a filling efficiency estimated value calculating means 132, a filling efficiency detecting means 133, and an EGR valve closing failure determining means 134 in addition to the volumetric efficiency calculating means 11 and the target EGR rate calculating means 61.

  In the charging efficiency estimated value calculating means 132, the volume efficiency ηv calculated by the volume efficiency calculating means 11 of the first embodiment, the intake air temperature Ta detected by the intake air temperature sensor 33, and the atmospheric pressure Pa detected by the atmospheric pressure sensor 34 are displayed. Based on the above, the charging efficiency estimated value η cest is calculated by the following equation.

ηcest = (Pa / P0) × (T0 / Ta) × ηv (11)
However, P0 [kPa]: standard intake pressure (99 kPa),
T0 [K]: Standard intake air temperature (298K),
The expression (11) is the same as the expression obtained by solving the above-described expression (4) with respect to the charging efficiency in the second embodiment.

  The filling efficiency detection means 133 detects the actual filling efficiency. Regarding this, since a technique for calculating the cylinder air mass per intake using a collector response model is described in Japanese Patent Application Laid-Open No. 2000-161113, the cylinder air mass per intake is used. Detect the filling efficiency.

  FIG. 31 is a block diagram of the filling efficiency detection means 133. In FIG. 31, the charging efficiency detection means 133 includes voltage → flow rate calculation means 151, air flow meter error correction means 152, intake pulsation smoothing processing means 153, pressure change amount calculation means 154, cylinder intake mass calculation means 155 per intake air, A filling efficiency detection value calculation means 156 is provided.

  The voltage receiving the output voltage of the hot wire type air flow meter 141 → the flow rate calculation means 151 converts the air flow meter output voltage into an air flow rate Q0 (mass flow rate) by searching a predetermined table. The air flow meter error correction means 152 calculates a value obtained by multiplying the air flow rate Q0 by a correction coefficient as the error corrected air flow rate Qafm. Here, the correction coefficient is a value obtained by searching a predetermined map from the engine speed Ne and the virtual flow velocity (or throttle valve opening) obtained from FIG. The correction of the air flow rate Q0 is for correcting that the air flow rate Q0 becomes too large due to the influence of the intake pulsation.

  The intake pulsation smoothing processing unit 153 performs a smoothing process on the air flow rate Qafm after error correction by the following equation to calculate the throttle valve passing air flow rate Mt per unit time.

Mt = Qafm × weighted average coefficient + (1−weighted average coefficient) × Mt (previous value)
(12)
Where Mt (previous value): previous value of Mt,
The collector pressure change amount calculation means 154 that inputs the collecter 27 pressure Pcol detected by the collector pressure sensor 142 calculates a collector pressure change amount ΔP (= Pcol−Pcol (previous value)).

  The cylinder intake mass calculation means 155 per intake air calculates the cylinder intake mass Mc per intake air according to the following equation.

Mc0 = Mt−ΔP × Vcol / (R · Ta) (13)
Mc = coefficient × (Mc0 / Ne) / number of cylinders (14)
Where Vcol: collector volume,
Ta: intake air temperature,
R: gas constant,
The filling efficiency detection value calculation means 156 calculates the filling efficiency detection value ηcreal by the following equation.

ηcreal = Mc / Mcbase (15)
However, Mcbase: cylinder intake mass per intake (standard value) in the standard state,
Returning to FIG. 30, the EGR valve closing failure determination means 134 determines whether or not a closing failure has occurred in the EGR valve 25 as follows. That is, the charging efficiency detection value ηcreal and the charging efficiency estimation value ηcest are compared, and when the charging efficiency detection value ηcreal is large enough to be regarded as abnormal, it is diagnosed that the EGR valve 25 has a closed failure. More specifically, FIG. 32 shows an estimated charging efficiency value η cest (see the broken line) and a detected charging efficiency value η creal (see the solid line) when EGR gas is not introduced into the intake passage 22 due to a closed failure of the EGR valve 25. Are superimposed on each other, and a protrusion is formed that comes off to the side where the filling efficiency detection value ηcreal becomes larger than the estimated filling efficiency value ηcest. This is because if the EGR gas is not actually entered due to the EGR valve 25 being closed due to the EGR valve 25 being opened to introduce the EGR gas, the actual intake air amount enters the combustion chamber more than the estimated value. Yes, such a protrusion of the charging efficiency detection value ηcreal appears in the operation region where EGR is performed. In this case, since the characteristic shown in FIG. 32 is bilogarithmically displayed, the difference between the filling efficiency detection value ηcreal and the filling efficiency estimated value ηcest in the real number display is a ratio (deviation rate) in FIG. 32, and the deviation rate has a large target EGR rate. It gets bigger.

  As shown in FIG. 33, when the target EGR rate is taken on the horizontal axis and the deviation rate (= ηcreal / ηcest) between the charging efficiency detection value ηcreal and the estimated charging efficiency value ηcest when the EGR valve 25 is closed is taken on the vertical axis, A proportional relationship (correlation) is established between the two, and the deviation rate and the target EGR rate are substantially equal. Therefore, it can be said that the EGR valve 25 is suspected of being closed when it is close to this correlation line. However, since the deviation rate and the target EGR rate actually include errors, it is difficult to perform an accurate diagnosis particularly when the numerical values of the deviation rate and the target EGR rate are small. Therefore, in order to improve the certainty of the EGR valve 25 closing failure diagnosis, a condition (or region) is set which can reliably diagnose (detect) the closing failure of the EGR valve 25 with a small error of the deviation rate and the target EGR rate. . That is, as shown in FIG. 34, the region where the deviation rate is equal to or lower than the predetermined “closed failure determination deviation rate” or the region where the target EGR rate is equal to or lower than the predetermined “update permission EGR rate” Only the region where the deviation rate exceeds the “closed failure determination deviation rate” and the target EGR rate exceeds the “update permission EGR rate” is set as the closed failure determination region of the EGR valve 25 except from the region.

  The flowchart shown in FIG. 35 is for determining whether or not the EGR valve 25 has a closed failure, and shows the operation performed by the EGR valve closed failure determining means 134. The flow in FIG. 35 is executed at regular intervals (for example, every 10 ms).

  In FIG. 35, in step 161, the estimated charging efficiency value η cest calculated by the estimated charging efficiency value calculating means 132, the detected charging efficiency value η creal detected by the charging efficiency detecting means 133, the engine speed Ne, the cooling water temperature Tw, the target EGR rate. The virtual flow velocity is read from the virtual flow velocity or the virtual Mach number calculated by the Megr, the virtual flow velocity or virtual Mach number calculation means 17 in FIG.

  In step 162, it is checked whether the deviation rate update condition is satisfied. The deviation rate update condition determines that the deviation rate update condition is met when all the conditions are met by checking whether the following conditions are met. It is not determined that the rate update condition is satisfied.

    A) The EGR valve 25 is in a non-failure state.

    B) The engine rotational speed Ne is equal to or higher than a predetermined rotational speed (idle rotational speed).

    C) The rate of change per predetermined time of the charging efficiency detection value ηcreal or the charging efficiency estimated value ηcest is not more than a predetermined value.

    D) The cooling water temperature Tw is equal to or higher than a predetermined temperature. When the engine oil temperature is also detected, at least one of the coolant temperature Tw and the engine oil temperature must be equal to or higher than the predetermined temperature.

    E) The virtual flow velocity is in a high flow velocity state of approximately 60 to 100 m / s or more.

    F) The establishment of the above a) to e) has continued for a predetermined time or more.

  The establishment of the above (c) is required in order to determine whether the EGR valve 25 is closed normally. The reason why the above (d) is required is to perform a closed failure determination of the EGR valve 25 after the warm-up of the engine is completed. The reason why the above e) is required is that the projection shown in FIG. 32 appears only in this region.

  If the deviation rate update condition is satisfied, the process proceeds to step 163, and the target EGR rate Megr is compared with a predetermined update permission EGR rate. The update permission EGR rate is the target EGR rate (adapted value) that defines the boundary of the region where the closed failure determination is not shown in FIG. When the target EGR rate Megr is less than or equal to the update permission EGR rate, the current process is terminated.

  When the target EGR rate Megr exceeds the update permission EGR rate, the routine proceeds to step 164, where the ratio between the charging efficiency detection value ηcreal and the estimated charging efficiency value ηcest is set as the shift rate, that is, the shift rate tmp is calculated by the following equation.

tmp = ηcreal / ηcest (16)
In step 165, the weighted average value tmpave of the deviation rate is calculated by the following equation.

tmpave = (tmp + 15 × tmpave (previous)) / 16 (17)
However, tmpave (previous): previous value of tmp,
In step 166, the deviation rate update completion determination counter cnt (initially set to zero) is incremented by 1. In step 167, the deviation rate update completion determination counter cnt and 16 are compared. If the deviation rate amount update completion determination counter cnt does not exceed 16, the current process is terminated.

  If the operations of steps 164 to 166 are repeated from the next time, the deviation rate update end determination counter cnt will eventually exceed 16. At this time, the routine proceeds to step 168, where the deviation rate weighted average value tmpave is compared with a predetermined closed failure determination deviation rate. To do. The closed failure determination deviation rate is the deviation rate (adapted value) that defines the boundary of the region where the closed failure determination is not shown in FIG. When the deviation rate weighted average value tmpave exceeds the closing failure determination deviation rate, the routine proceeds to step 169, where it is determined that the EGR valve 25 has a closing failure. On the other hand, when the deviation rate weighted average value tmpave is equal to or less than the closing failure determination deviation rate, the routine proceeds from step 168 to step 171, where it is determined that no closing failure has occurred in the EGR valve 25.

  In step 170, the deviation rate update end determination counter cnt = 0 is set in order to determine again the closed failure of the EGR valve 25 next time. The deviation rate update end determination counter cnt = 0 increments the shift rate update end determination counter cnt at step 166. Every time the shift rate update end determination counter cnt exceeds 16, the process proceeds to steps 168 to 171. The closed failure determination of the EGR valve 25 is performed.

According to the tenth embodiment (the invention described in claim 5 ), the suction capacity as a pump for sucking the air downstream of the throttle valve 21 (throat portion) into the combustion chamber, and the throttle valve opening area Atvo (throat portion area) Based on the above, the virtual flow velocity u ′ or the virtual Mach number M ′ is calculated, the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity u ′ or the virtual Mach number M ′, and the throttle valve is added to the normalized volumetric efficiency. 21 The volume efficiency ηv is calculated by multiplying the efficiency (ηvwot) of sucking the downstream air into the pump, the charging efficiency estimated value ηcest is calculated based on this volumetric efficiency ηv, the actual charging efficiency is detected, and this charging efficiency Since a deviation rate tmp which is a ratio of the detected value ηcreal and the charging efficiency estimated value ηcest is calculated, it is determined whether or not the EGR valve 21 (EGR device) has a closed failure based on the deviation rate tmp. In addition to being able to construct a new intake model with a general purpose engine, a flow sensor is further provided in the EGR passage 24 to determine whether EGR gas is actually flowing in the EGR region (if EGR gas is not flowing, the EGR valve 25, or a temperature sensor is provided downstream of the EGR valve 25, and whether or not EGR gas is actually flowing in the EGR region (if the temperature downstream of the EGR valve is substantially equal to the intake air temperature) It is possible to diagnose (detect) whether or not the EGR valve 25 has a closed failure without diagnosing the EGR valve 25 having a closed failure), and thereby the EGR gas flow rate, EGR gas temperature, etc. This eliminates the need to use a sensor to detect and is excellent in cost.

  FIG. 36 shows an eleventh embodiment that replaces FIG. 30 of the tenth embodiment. The same parts as those in FIG. 30 are given the same numbers.

  In the tenth embodiment, it is diagnosed whether or not the EGR valve 25 has a closed failure based on the volumetric efficiency ηv calculated by the volumetric efficiency calculating means 11 in FIG. Based on the volumetric efficiency ηv calculated by the efficiency calculating means 11, it is diagnosed whether or not an open failure has occurred in the EGR valve 25.

  In FIG. 36, when the EGR valve open failure determination means 181 compares the charging efficiency detection value ηcreal with the estimated charging efficiency value ηcest and the charging efficiency detection value ηcreal is small enough to be regarded as abnormal, an open failure has occurred in the EGR valve 25. Diagnose. Here, the concept and configuration of the open failure determination of the EGR valve 25 are the same as those in the tenth embodiment, and therefore, differences from the tenth embodiment will be mainly described.

  FIG. 37 shows an estimated charging efficiency value ηcest (see the broken line), a detected charging efficiency value ηcreal (see the solid line) when EGR gas has been introduced into the intake passage 22 due to an open failure of the EGR valve 25 that should be closed. Unlike the case shown in FIG. 32, there is a portion where the detected charging efficiency value ηcreal deviates below the estimated charging efficiency value ηcest. This is because when the EGR valve 25 is closed to stop the introduction of the EGR gas but the EGR gas is actually introduced into the intake passage 22 due to an open failure of the EGR valve 25, the actual intake air amount is estimated from the estimated value. This is because the charging efficiency detection value ηcreal falls in an operation region where EGR is not performed. In this case, since the horizontal axis and the vertical axis are logarithmic in FIG. 37, the difference between the charging efficiency detection value ηcreal and the charging efficiency estimated value ηcest in the real number display is a ratio (deviation rate) in FIG. 37, and the deviation rate is the target EGR rate. The larger the value, the smaller the negative value.

  As shown in FIG. 38, the horizontal axis represents the target EGR rate, and the vertical axis represents the deviation rate (= ηcreal / ηcest) between the charging efficiency detection value ηcreal and the estimated charging efficiency value ηcest when the EGR valve 25 is open. A proportional relationship (correlation) is established between the two, and the absolute value of the deviation rate and the target EGR rate are substantially equal. For this reason, when it is close to this correlation line, it can be said that the EGR valve 25 is suspected of being open. However, since the deviation rate and the target EGR rate actually include errors, it is necessary to exclude a region where accurate diagnosis (detection) is difficult. Therefore, in order to improve the reliability of the EGR valve 25 open failure determination, a condition (or region) is set that can reliably diagnose (detect) the open failure of the EGR valve 25 with little error in the deviation rate and the target EGR rate. . That is, as shown in FIG. 39, an area where the deviation rate is equal to or higher than a predetermined “open failure determination deviation rate” or an area where the target EGR rate is equal to or lower than a predetermined “update permission EGR rate” is an open failure determination area of the EGR valve 25. Only the region where the deviation rate is less than the “open failure judgment deviation rate” and the target EGR rate exceeds the “update permission EGR rate” is set as the EGR valve 25 open failure judgment region.

  The flow in FIG. 40 is for determining whether or not an open failure has occurred in the EGR valve 25, and shows the operation performed by the EGR valve open failure determining means 181. The flow in FIG. 40 is executed at regular time intervals (for example, every 10 ms). The same steps as those in FIG. 35 are given the same step numbers.

  The difference from the tenth embodiment will be mainly described. In step 174, the deviation rate weighted average value tmpave is compared with a predetermined open failure determination deviation rate. The open failure determination shift rate is a shift rate (adapted value) that defines the boundary of the region where open failure determination is not shown in FIG. When the deviation rate weighted average value tmpave is less than the open failure determination deviation rate, the routine proceeds to step 175, where it is determined that an open failure has occurred in the EGR valve 25. On the other hand, when the deviation rate weighted average value tmpave is equal to or greater than the open failure determination deviation rate, the routine proceeds from step 174 to step 176, where it is determined that no open failure has occurred in the EGR valve 25.

  In step 170, the deviation rate update end determination counter cnt = 0 is set in order to determine again the open failure of the EGR valve 25 next time. The deviation rate update end determination counter cnt = 0 is incremented by the shift rate update end determination counter cnt at step 166. Every time the shift rate update end determination counter cnt exceeds 16, the process proceeds to steps 174 to 176. An open failure determination of the EGR valve 25 is performed.

According to the eleventh embodiment (the invention described in claim 6 ), the suction capacity as a pump for sucking the air downstream of the throttle valve 21 (throat portion) into the combustion chamber, and the throttle valve opening area Atvo (throat portion area) Based on the above, the virtual flow velocity u ′ or the virtual Mach number M ′ is calculated, the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity u ′ or the virtual Mach number ′, and the throttle valve 21 is added to the normalized volumetric efficiency. The volumetric efficiency ηv is calculated by multiplying the efficiency (ηvwot) of sucking the downstream air into the pump, the charging efficiency estimated value ηcest is calculated based on this volumetric efficiency, the actual charging efficiency is detected, and this charging efficiency detection value Since the deviation rate tmp, which is the ratio of ηcreal to the estimated charging efficiency ηcest, is calculated and it is determined whether there is an open failure in the EGR valve 21 (EGR device) based on this deviation rate. A useful intake model can be newly constructed, and a flow sensor is further provided in the EGR passage 24 to determine whether EGR gas is actually flowing in the non-EGR region (if EGR gas is flowing, the EGR valve 25 Or a temperature sensor is provided downstream of the EGR valve 25 to determine whether or not EGR gas is actually flowing in the non-EGR region (if the temperature downstream of the EGR valve is higher than the intake air temperature) It is possible to diagnose (detect) whether or not there is an open failure in the EGR valve 25 without diagnosing whether there is an open failure in the valve 25, thereby detecting the EGR gas flow rate, EGR gas temperature, etc. This eliminates the need to use the sensor, and is excellent in cost.

  In the tenth and eleventh embodiments, it is determined whether or not the EGR valve 25 has a closed failure or an open failure based on the deviation rate tmp, which is the ratio between the charging efficiency detection value ηcreal and the charging efficiency estimated value ηcest. Whether or not the EGR valve 25 has a closed failure or an open failure may be determined based on the difference between the detected charging efficiency value ηcreal and the estimated charging efficiency value ηcest.

  In the tenth and eleventh embodiments, the EGR valve 25 as the external EGR device has been described. However, the EGR method is not limited to this, and as described above in the fourth embodiment, the internal EGR device. There is an engine with The tenth and eleventh embodiments can also be applied to an engine including such an internal EGR device. That is, in the case of an engine having an internal EGR device, a target value or actual value of the internal EGR rate may be used instead of the target EGR rate Megr.

  FIG. 41 shows a twelfth embodiment that replaces FIG. 1 of the first embodiment. The same parts as those in FIG.

  To explain mainly the difference from the first embodiment, the flow rate calculation means 185 is added to the volume efficiency calculation means 11. In this flow velocity calculation means 185, the volume efficiency ηv calculated by the volume efficiency calculation means 11 and the virtual flow velocity u ′ calculated by the virtual flow velocity or virtual Mach number calculation means 17 are calculated by the following equation or by the volume efficiency calculation means: The flow velocity u is calculated from the volume efficiency ηv calculated by 11, the virtual Mach number M ′ calculated by the virtual flow velocity or virtual Mach number calculating means 17, and the sound velocity c by the following equation.

u [m / s] = u ′ [m / s] × ηv (18a)
u [m / s] = M ′ × c [m / s] × ηv (18b)
In general, a butterfly type throttle valve is used for an engine, and it is well known that the flow velocity of intake air flowing through the throttle valve portion is calculated using a general cylindrical pipe fluid model or a standard orifice model ( JP 2002-130039).

  However, when the flow velocity of the intake air actually flowing through the butterfly throttle valve portion is measured, the measured value does not match the result calculated by applying these models as they are. The reason seems to be that the physical behavior of the intake air flowing through the butterfly throttle valve portion is different from the model even if the throttle valve opening area is the same. A particularly noticeable difference between the measured value and the result calculated by applying the model as it is is the low Reynolds number flow region where the butterfly throttle valve is almost fully open (throttle valve opening area is large).

  More specifically, FIG. 42 shows the throttle valve front-rear intake pressure ratio (P2 / P1), which is the ratio of the upstream intake pressure P1 and the downstream intake pressure P2 of the butterfly throttle valve, on the horizontal axis. The predetermined value A is the ratio of the intake pressure before and after the throttle valve with respect to the critical pressure, and the predetermined value B is the intake flow velocity during choke. In this case, according to the theoretical formula (isothermal change model) when the intake air is assumed to change isothermally before and after the butterfly throttle valve, the throttle valve front-rear intake pressure ratio (P2 / P1) is predetermined as indicated by a thin solid line. Until the value A is reached, the flow velocity matches the predetermined value B, and after the throttle valve front-rear intake pressure ratio (P2 / P1) reaches the predetermined value A, the flow velocity gradually decreases. Further, according to the theoretical formula (adiabatic change model) when the intake air is assumed to change adiabatically before and after the butterfly throttle valve, until the throttle valve front and rear intake pressure ratio (P2 / P1) reaches a predetermined value A as shown by the broken line. The flow velocity coincides with a predetermined value C (a predetermined value larger than the predetermined value B), and after the throttle valve front-rear intake pressure ratio (P2 / P1) reaches the predetermined value A, the flow velocity gradually decreases.

  On the other hand, the measured value (experimental value) is as shown by the alternate long and short dash line, and agrees with the theoretical formula when it is assumed that the throttle valve front-rear intake pressure ratio (P2 / P1) changes isothermally in a relatively large region.

Thus, according to the twelfth embodiment (the invention described in claim 7 ), the suction capacity as a pump for sucking the air downstream of the throttle valve 21 (throat portion) into the combustion chamber, and the throttle valve opening area Atvo ( The virtual flow velocity u ′ or the virtual Mach number M ′ is calculated based on the throat portion area), and the normalized volume efficiency is calculated based on the calculated virtual flow velocity u ′ or the virtual Mach number M ′. The volumetric efficiency ηv is calculated by multiplying the efficiency by the efficiency (ηvwot) of sucking the air downstream of the throttle valve 21 into the pump, and the volumetric efficiency ηv is multiplied by the virtual flow velocity u ′, or Since the flow velocity u is calculated by multiplying M 'by the speed of sound c, it is possible to construct a new engine intake model that is versatile, and in the area where the butterfly throttle valve is almost fully open. The flow rate of intake air flowing through the butterfly type throttle valve unit can be accurately calculated.

  FIG. 43 is a block diagram of the thirteenth embodiment, which replaces FIG. 30 of the tenth embodiment. The same parts as those in the tenth embodiment are given the same numbers.

  The difference from the tenth embodiment will be mainly described. In the fuel injection pulse width calculation means 191 (fuel supply amount calculation means), the basic injection pulse width Tp is calculated using the estimated charging efficiency value ηcest as shown in the following equation. Thereafter, a fuel injection pulse width Ti (fuel supply amount) at the time of sequential injection is calculated.

Tp [ms] = coefficient 1 × coefficient 2 × η cest (19)
Ti [ms] = Tp × TFBYA × α × 2 + Ts (20)
However, coefficient 1: Conversion factor to cylinder intake per intake,
Coefficient 2: Conversion coefficient of cylinder intake amount per intake to fuel injection pulse width,
TFBYA: target equivalent ratio,
α: Air-fuel ratio feedback correction coefficient,
Ts [ms]: Invalid injection pulse width,
At a predetermined injection timing, fuel injection is performed by opening the fuel injection valve 29 (fuel supply means) for each cylinder only during the period of the fuel injection pulse width Ti.

According to the thirteenth embodiment (the invention described in claim 8 ), the suction capacity as a pump for sucking the air downstream of the throttle valve 21 (throat portion) into the combustion chamber, and the throttle valve opening area Atvo (throat portion area) Based on the above, the virtual flow velocity u ′ or the virtual Mach number M ′ is calculated, the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity u ′ or the virtual Mach number M ′, and the throttle valve is added to the normalized volumetric efficiency. 21 Volumetric efficiency ηv is calculated by multiplying the efficiency (ηvwot) of sucking downstream air into the pump, a charging efficiency estimated value ηcest is calculated based on the volumetric efficiency ηv, and fuel injection is performed based on the charging efficiency estimated value ηcest Since the pulse width Ti (fuel supply amount) is calculated, it is possible to construct a new engine versatility intake model, and in addition to the L-Jetronic fuel injection system. Can without using expensive parts such as a pressure sensor which is required to the fuel injection device of the air flow meter and D- Jetronic system estimates the first intake per cylinder intake air quantity the fuel is injected as a.

  FIG. 44 shows a fourteenth embodiment that replaces FIG. 30 of the tenth embodiment. The same parts as those in the tenth embodiment are given the same numbers.

  The fourteenth embodiment is based on the assumption that the fuel injection pulse width Ti (fuel supply amount) is calculated based on the detected charging efficiency value, and the estimated charging efficiency value ηcest and the detected charging efficiency detection means 133. Compared with the value ηcreal, when the charging efficiency detection value ηcreal deviates to a larger side or a smaller side so that it can be regarded as abnormal than the estimated charging efficiency value ηcest, the air flow meter 141 as the charging efficiency detection means outputs an abnormal output. The charging efficiency detection value ηcreal is limited to a predetermined range, the fuel injection pulse width Ti is calculated based on the charging efficiency detection value ηcreal limited to the predetermined range, and the charging efficiency detection value ηcreal is predetermined. When the state limited to the above range continues for a predetermined time or longer, the fuel is detected using the estimated charging efficiency value ηcest instead of the detected charging efficiency value ηcreal for fail-safe. And it calculates the elevation pulse width Ti.

  Here, the differences from the tenth embodiment will be mainly described. First, the air flow meter output abnormality determining means 201 first detects the charging efficiency detected value ηcreal, the upper limit value ηcestMAX of the estimated charging efficiency value, and the lower limit value ηcestMIN of the estimated charging efficiency value. And the charging efficiency detection value ηcreal exceeds the charging efficiency estimated value upper limit value ηcestMAX, or conversely, when the charging efficiency ηcreal falls below the charging efficiency estimated value lower limit value ηcestMIN, the fail-safe processing means 202 detects the charging efficiency detection value. ηcreal is limited to the upper limit value ηcestMAX and the lower limit value ηcestMIN, and the fuel injection pulse width calculation unit 203 calculates the fuel injection pulse width Ti according to the above formulas (19) and (20) based on the limited charging efficiency detection value ηcreal. Is calculated. Further, when the air flow meter output abnormality determining means 201 determines that the state in which the charging efficiency detection value ηcreal is limited to the upper limit value ηcestMAX or the lower limit value ηcestMIN has continued for a predetermined time or more, it is determined that there is an abnormality in the airflow meter output. The fail safe processing means 202 switches the detected charging efficiency value ηcreal to the estimated charging efficiency value ηcest, and after switching, the fuel injection pulse width calculating means 203 uses the estimated charging efficiency value ηcest instead of the detected charging efficiency value ηcreal. The fuel injection pulse width Ti is calculated by the above equations (19) and (20).

  The upper limit value η cestMAX of the estimated charging efficiency value and the lower limit value η cestMIN of the estimated charging efficiency value may be calculated by adding a predetermined difference or rate to the estimated charging efficiency value η cest.

  Here, the operation of the air flow meter output abnormality determination unit 201 and the fail safe processing unit 202 will be described with reference to FIG. 45. The alternate long and short dash line in the charging efficiency waveform shown in the upper part of FIG. 45 indicates the movement of the estimated charging efficiency value ηcest. A limited range of a predetermined range is provided above and below the estimated charging efficiency ηcest. A waveform indicated by a thin solid line above the estimated charging efficiency value ηcest is the upper limit value ηcestMAX of the estimated charging efficiency value, and a waveform indicated by a thin solid line below the estimated efficiency value ηcest is the lower limit value ηcestMIN of the estimated charging efficiency value. On the other hand, a thick solid line in the filling efficiency waveform shown in the upper part of FIG. 45 indicates the movement of the filling efficiency detection value ηcreal detected based on the air flow meter output.

  Now, assuming that the output of the air flow meter 141 becomes abnormally large at the timing t1, and the charging efficiency detection value ηcreal calculated based on the air flow meter output becomes larger than the upper limit value ηcestMAX of the estimated charging efficiency, At the timing of t1, the charging efficiency detection value ηcreal is limited to the upper limit value ηcestMAX of the estimated charging efficiency value, and the limit range sticking flag is switched from 0 to 1 as shown in the third row from the bottom of FIG. The decrement of the limited range duration timer is started as shown in the second row from the bottom of FIG.

  Note that, for example, when a short circuit occurs as a cause of an abnormal air flow meter output, the detected charging efficiency value ηcreal falls below the lower limit value ηcestMIN of the estimated charging efficiency value and approaches zero. . However, the cause of the abnormality in the air flow meter output can be considered either in the case of being limited to the upper limit value η cestMAX of the estimated charging efficiency value or in the case of being limited to the lower limit value η cestMIN of the estimated charging efficiency value. FIG. 45 schematically shows the case where the detected charging efficiency value ηcreal is limited to the upper limit value ηcestMAX of the estimated charging efficiency value. Therefore, the same applies to the case where the detected charging efficiency value ηcreal is limited to the lower limit value ηcestMIN of the estimated charging efficiency value.

  On the other hand, the engine controller 10 determines whether or not an abnormality determination restriction condition is satisfied. This is because, when all the conditions are satisfied by checking whether or not the following conditions are satisfied, it is determined that the abnormality determination restriction condition is satisfied, and the abnormality determination restriction flag = 1 is set. If not, it is not determined that the abnormality determination restriction condition is satisfied, and the abnormality determination restriction flag = 0.

    G) The atmospheric state detecting means (33, 34) and the volumetric efficiency calculating means 11 are in a non-failure state.

    H) The engine rotational speed Ne is equal to or higher than a predetermined rotational speed (idle rotational speed).

B) The rate of change per predetermined time of the charging efficiency detection value ηcreal or the charging efficiency estimated value ηcest is not more than a predetermined value.

    N) The cooling water temperature Tw is equal to or higher than a predetermined temperature. When the engine oil temperature is also detected, at least one of the coolant temperature Tw and the engine oil temperature must be equal to or higher than the predetermined temperature.

    B) The above conditions (g) to (d) have been established for a predetermined time or more.

  The abnormality determination limit flag becomes 1 at the timing of t2, and the abnormality determination flag is set at the timing of t4 after a predetermined delay time further from the timing of t3 when the limit range extension duration timer becomes zero in this state. Is switched from 0 to 1 as in the lowermost stage (determined that there is an abnormality in the air flow meter output).

  In this way, when it is determined that there is an abnormality in the air flow meter output, fail-safe processing is performed. That is, from the timing t4, the charging efficiency detection value ηcreal limited to the upper limit value ηcestMAX of the charging efficiency estimation value is switched to the charging efficiency estimation value ηcest. However, if the charging efficiency detection value ηcreal is switched from the charging efficiency detection value ηcreal to the charging efficiency estimation value ηcest in a stepwise manner, the fuel injection amount changes abruptly. In order to avoid this sudden change in the fuel injection amount, a ramp process is performed at the time of switching.

  As a result, the detected charging efficiency value ηcreal that is in the upper limit value ηcestMAX of the estimated charging efficiency value gradually approaches the estimated charging efficiency value ηcest from the timing t4, and coincides with the estimated charging efficiency value ηcest at the timing t5. ing.

  In this way, when it is determined that there is an abnormality in the air flow meter output, the estimated charging efficiency value ηcest is used for calculating the fuel injection pulse width Ti after t4 instead of the detected charging efficiency value ηcreal.

According to the fourteenth embodiment (the invention described in claims 9 and 12 ), the suction capacity as a pump for sucking the air downstream of the throttle valve 21 (throat portion) into the combustion chamber, and the throttle valve opening area Atvo (throat portion) The virtual flow velocity u ′ or the virtual Mach number M ′ is calculated based on the area), and the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity u ′ or the virtual Mach number M ′. The volumetric efficiency ηv is calculated by multiplying the efficiency (ηvwot) of sucking the air downstream of the throttle valve 21 into the pump, the charging efficiency estimated value ηcest is calculated based on the volumetric efficiency ηv, and based on the charging efficiency estimated value ηcest. On the premise of calculating the fuel injection pulse width Ti (fuel supply amount), a value obtained by adding a predetermined difference or rate to the charging efficiency estimated value ηcest is an abnormality determination upper limit value ηcestMAX, The lower limit value ηcestMIN is calculated and the charging efficiency is detected. When the detected charging efficiency value ηcreal exceeds the abnormality determination upper limit value ηcestMAX, the abnormality determination upper limit value ηcestMAX is detected, and the charging efficiency detection value ηcreal is the abnormality determination lower limit value. When the value is lower than ηcestMIN, the abnormality determination lower limit value ηcestMIN is limited, and when the charging efficiency detection value ηcreal is limited to the abnormality determination upper limit value or the abnormality determination lower limit value, the air flow meter 141 ( Since it is determined that an abnormality has occurred in the output of the charging efficiency detecting means), it is possible to construct a new intake model having a general purpose engine, and to further diagnose the air flow meter 141.

According to the fourteenth embodiment (the invention described in claim 8 ), when the charging efficiency detection value ηcreal is limited to the abnormality determination upper limit value ηcestMIN or the abnormality determination lower limit value ηcestMIN, the limited charging efficiency Based on the detected value ηcreal and when it is determined that an abnormality has occurred in the output of the air flow meter 141, the charging efficiency detected value ηcreal is switched to the estimated charging efficiency value ηcest, and the fuel is calculated based on the switched estimated charging efficiency value ηcest. Since the injection pulse width Ti (fuel supply amount) is calculated, even when an abnormality occurs in the output of the air flow meter 141, abnormal fuel supply is not performed based on the output of the abnormal air flow meter 141. Can improve the reliability of the system.

  FIG. 46 shows a fifteenth embodiment that replaces FIG. 44 of the fourteenth embodiment. The same parts as those in the fourteenth embodiment are given the same numbers.

  In the fifteenth embodiment, assuming that the target throttle valve opening is calculated and the throttle valve actuator 213 is controlled so as to obtain the target throttle valve opening, the output of the air flow meter 141 is increased by the intake pulsation. When it is determined that there is an abnormality that increases the error, the target throttle valve opening is limited to a predetermined upper limit value.

  More specifically, the target throttle valve opening calculation means 212 calculates the target throttle valve opening based on the accelerator operation amount detected by the accelerator sensor 31 and the engine speed Ne. The target throttle valve opening calculation method described in JP-A-11-182298 can be used as it is.

  The air flow meter output abnormality determining means 211 determines whether or not there is an abnormality in the air flow meter output that increases the positive error due to intake air pulsation as follows.

  In FIG. 47, the horizontal axis represents the throttle valve opening, and the vertical axis represents the intake air amount. When there is no abnormality in the air flow meter output that causes a positive error due to intake pulsation to increase, the intake air amount converges to a predetermined value D in the vicinity of the fully open throttle valve as shown by the solid line. However, when there is an abnormality in the air flow meter output that causes a positive error due to intake air pulsation to increase, the intake air amount is the true intake air amount (see the solid line) near the throttle valve fully open (intake air saturation region) as shown by the broken line. It grows beyond. The cause of this is that the frequency of occurrence of intake pulsation may change when the shape of the intake duct is deformed from the standard shape due to disconnection, disconnection, breakage, or replacement of the intake pipe. Due to such a change in the frequency of occurrence of intake pulsation, depending on the air flow meter 141, a large positive error may occur in a region where the throttle valve opening is large, resulting in an abnormality in the calculation of the fuel injection amount and the operation of various operating parameters.

  That is, since the air flow meter output abnormality has a positive error that increases with the intake pulsation, the air flow meter output abnormality determining means 211 may cause intake pulsation as shown in FIG. In a region, specifically, in a low flow velocity region where the virtual flow velocity is approximately 60 to 100 m / s or less, the time or number of times when the difference or ratio between the filling efficiency detection value ηcreal and the filling efficiency estimation value ηcest exceeds a predetermined value is measured. When the measured value exceeds the determination value, it is determined that the air flow meter output has an abnormality in which the positive error due to the intake pulsation increases.

  Here, the abnormality determination region is limited as a region where the intake pulsation increases.If not limited, the intake pulsation occurs based on the principle such as Helmholtz resonance as described above. This is because it becomes difficult to specify where resonance occurs when a shape change occurs.

  In the target throttle valve opening restricting means 213, when the air flow meter output abnormality determining means 211 determines that the air flow meter output has an abnormality that causes a positive error due to intake pulsation to increase, the target throttle valve opening restricting means 213 reduces the target throttle valve opening to a predetermined upper limit value. Restrict to. That is, when there is an abnormality in which the positive error due to intake air pulsation increases in the air flow meter output, as shown in FIG. 47, an upper limit value E is set before the intake air saturation region, and a throttle valve in a region exceeding the upper limit value E is set. Do not use the opening. In this case, the pressure loss due to the throttle valve opening being limited to the upper limit value E is reduced by only a few percent when viewed from the fully open output of the throttle valve 21, so that even if the throttle valve opening is limited to the upper limit value E, The vehicle can continue to travel within a range that does not interfere with normal traveling. In other words, the intake pulsation of the air flow meter unit is more attenuated if the throttle valve 21 is throttled and the flow velocity of the intake air passing through the throttle valve 21 is accelerated to a region that exhibits the characteristics of the compressible fluid. Since it is not transmitted (intake pulsation becomes small), the virtual flow velocity is about 60 to 100 m / s (Mach number 0.2 to 0.3) or more, or more than the flow velocity corresponding to this value (see FIG. 48). The upper limit value E of the throttle valve opening may be determined.

  In this way, the value that can be taken as the target throttle valve opening is limited to the range up to the upper limit value E in the event of an abnormal increase in the positive error due to the intake air pulsation of the air flow meter output, and the target throttle valve opening within this limited range. The actuator 213 drives the throttle valve 21 so that the degree is obtained.

According to the fifteenth embodiment (the invention described in claim 13 ), the suction capability as a pump for sucking the air downstream of the throttle valve 21 (throat portion) into the combustion chamber, and the throttle valve opening area Atvo (throat portion area) Based on the above, the virtual flow velocity u ′ or the virtual Mach number M ′ is calculated, the normalized volumetric efficiency is calculated based on the calculated virtual flow velocity u ′ or the virtual Mach number M ′, and the throttle valve is added to the normalized volumetric efficiency. 21 Volumetric efficiency ηv is calculated by multiplying the efficiency (ηvwot) of sucking downstream air into the pump, and the charging efficiency estimated value ηcest is calculated based on the volumetric efficiency ηv, and the charging efficiency is detected, and intake pulsation may occur The time or number of times when the difference or ratio between the detected charging efficiency value ηcreal and the estimated charging efficiency value ηcest exceeds a predetermined value in a characteristic region is measured. It is determined whether or not there is an abnormality with a large positive error due to intake pulsation in the output of the air flow meter 141 (filling efficiency detection means), and when it is determined that there is an abnormality with a large positive error due to intake pulsation, no intake pulsation occurs. The target throttle valve opening is limited to a predetermined value and the throttle valve is controlled so that the target throttle valve opening is limited to this predetermined value. In addition, it is possible to prevent deterioration in drivability even when an abnormality with a large plus error due to intake air pulsation occurs in the output of the air flow meter 141.

Further, according to the fifteenth embodiment (the invention described in claim 15 ), the upper limit value E, which is a limit value, is set before the throttle valve is fully opened (saturated region of the intake air amount), so the output of the air flow meter 141 is output. Even when an abnormality with a large positive error occurs due to intake pulsation, a decrease in engine output can be suppressed to a small level, and a significant decrease in drivability can be prevented.

  On the other hand, when an abnormality with a large plus error due to intake air pulsation occurs in the aflow meter output, it is conceivable that the upper limit value can be reduced to enable only low-speed driving. Will occur.

In the fourteenth and fifteenth embodiments, since the air flow meter 141 is a sensor that detects a mass flow rate, a filling efficiency detection value η cest detected by the air flow meter 141 as a filling efficiency detection unit, and a filling efficiency estimation value η cest To determine whether there is an abnormality in the air flow meter output as the charging efficiency detection means, or whether there is an abnormality with a large positive error due to the intake pulsation in the air flow meter output as the charging efficiency detection means. However, the fourteenth and fifteenth embodiments are not limited to sensors that detect mass flow rate. For example, for a volume flow sensor (eg, a pressure sensor), the actual volume efficiency ηvreal detected by the volume flow sensor as the actual volume efficiency detection means and the volume efficiency estimated value ηvest (that is, in the first embodiment). By comparison with the obtained volumetric efficiency (ηv), whether there is an abnormality in the output of the volumetric flow sensor as the actual volumetric efficiency detecting means or the positive error due to the intake pulsation is large in the volumetric flow rate sensor as the actual volumetric efficiency detecting means It can be determined whether or not an abnormality has occurred (the inventions according to claims 12 and 14 ).

  FIG. 49 shows a sixteenth embodiment that replaces FIG. 8 of the second embodiment. The same number is attached | subjected to the same part as 2nd Embodiment.

  The difference from the second embodiment will be mainly described. The accelerator required opening area calculating means 221 calculates the accelerator required opening area AAPO of the throttle valve 21 from the accelerator operation amount detected by the accelerator sensor 31 and the engine rotational speed Ne. calculate.

  The reciprocal number of the virtual flow velocity or the reciprocal number of the virtual Mach number 222 calculates the virtual flow velocity from the accelerator required opening area AAPO, the engine speed Ne, the volume efficiency ηvwot when the throttle valve is fully opened, and the total stroke volume Vtotal by the following equation. The reciprocal of the virtual Mach number is calculated from the reciprocal, or the accelerator required opening area AAPO, the engine speed Ne, the throttle valve fully open volumetric efficiency ηvwot, the total stroke volume Vtotal, and the sound speed c by the following equation.

Reciprocal of virtual flow velocity [s / m] = AAPO [m ² ]
/ (Vtotal [m ³ ] × ηvwot × (Ne [rpm] / 120))
... (21)
Reciprocal of virtual Mach [anonymous number] = c [m / s] × {AAPO [m ² ]
/ (Vtotal [m ³ ] × ηvwot × (Ne [rpm] / 120))}
... (22)
Expressions (21) and (22) are expressions similar to the above expressions (1) and (2) for calculating the virtual flow velocity u ′ or the virtual Mach number M ′.

  The target basic normalized volumetric efficiency calculating means 223 searches the table having the contents of FIG. 50A from the reciprocal of the virtual flow velocity, or searches the table having the contents of FIG. 50B from the reciprocal of the virtual Mach number. Thus, the normalized volumetric efficiency is calculated, and the calculated normalized volumetric efficiency is set as the target basic normalized volumetric efficiency. 50 (a) and 50 (b) show the virtual flow velocity u ′ or the virtual Mach number M ′ on the horizontal axis in the contents shown in FIGS. 5 (a) and 5 (b), the reciprocal of the virtual flow velocity or the virtual Mach. This is the reciprocal of the number.

  The target basic volume efficiency calculating means 224 multiplies the target basic normalized volume efficiency by the volume efficiency ηvwot when the throttle valve is fully opened, that is, calculates the target basic volume efficiency tηv0 by the following equation.

tηv0 = target basic normalized volumetric efficiency × ηvwot (23)
The target volume efficiency calculation means 225 divides this target basic volume efficiency tηv0 by the target equivalent ratio TFBYA, that is, calculates the target volume efficiency tηv by the following equation.

tηv = tηv0 / TFBYA (24)
The target normalized volumetric efficiency calculation means 226 divides this target volumetric efficiency tηv by the volumetric efficiency ηvwot when the throttle valve is fully opened, that is, calculates the target normalized volumetric efficiency by the following equation.

Target normalized volumetric efficiency = tηv / ηvwot (25)
In the reciprocal of the target virtual flow velocity or the reciprocal of the target virtual Mach number and the calculation means 227, the reciprocal of the target virtual flow velocity or the target normalization is searched by searching a table having the contents shown in FIG. The reciprocal of the target virtual Mach number is calculated by searching a table whose contents are shown in FIG.

  The target throttle valve opening area calculating means 228 calculates the target throttle valve opening area tAtvo by the following equation from the reciprocal of these target virtual flow speeds, the engine speed Ne, the throttle valve fully open volume efficiency ηvwot, and the total stroke volume Vtotal. Alternatively, the target throttle valve opening area tAtvo is calculated from the reciprocal of the target virtual Mach number, the engine rotational speed Ne, the throttle valve fully opened volumetric efficiency ηvwot, the total stroke volume Vtotal, and the sound speed c by the following equation.

tAtvo [m ² ] = (reciprocal of target virtual flow velocity)
× (Vtotal [m ³ ] × ηvwot × (Ne [rpm] / 120))
... (26)
tAtvo [m ² ] = {(reciprocal of target virtual Mach number)
× (Vtotal [m ³ ] × ηvwot × (Ne [rpm] / 120))}
/ C [m / s] (27)
The target throttle valve opening calculation means 42 calculates the target throttle valve opening from the target throttle valve opening area tAtvo, and the throttle valve control means 43 controls the throttle valve opening so as to be the target throttle valve opening.

According to a sixteenth embodiment shaped condition, so that the target engine torque and the target air-fuel ratio according to the operating condition of the engine is obtained, the fuel by the intake air amount, also depending on the target equivalent ratio fuel injection valve by the throttle valve In the engine control device for controlling the supply amount, the accelerator required opening area AAPO is calculated from the accelerator operation amount and the engine rotational speed Ne, and the volume efficiency ηvwot when the throttle valve is fully opened is calculated from the engine rotational speed Ne. The reciprocal of the virtual flow velocity or the reciprocal of the virtual Mach number is calculated based on the opening area AAPO, the engine speed Ne, the volume efficiency ηvwot when the throttle valve is fully opened, and the total stroke volume Vtotal. The target basic normalized volumetric efficiency is calculated from the reciprocal of the Mach number, and the throttle is added to the target basic normalized volumetric efficiency. The target basic volume efficiency tηv0 is calculated by multiplying the fully open volume efficiency ηvwot, the target basic volume efficiency ηv is divided by the target equivalent ratio to calculate the target volume efficiency tηv, and the target volume efficiency tηv is calculated as the throttle valve. The target normalized volumetric efficiency is calculated by dividing by the fully open volumetric efficiency ηvwot, the reciprocal of the target virtual flow velocity or the reciprocal of the target virtual Mach number is calculated from the target normalized volumetric efficiency, and the reciprocal of the target virtual flow velocity or the target virtual A target throttle valve opening area is calculated based on the reciprocal of the Mach number, the engine speed Ne, the throttle valve fully open volume efficiency ηvwot, and the total stroke volume Vtotal, and the target throttle valve opening area is calculated from the target throttle valve opening area. And the throttle valve opening is controlled so as to be the target throttle valve opening, so that the same effect as in the second embodiment can be obtained.

  Specifically, the relationship between the target basic normalized volumetric efficiency and the inverse of the virtual flow velocity or the inverse of the virtual Mach number, or the relationship between the target normalized volumetric efficiency and the inverse of the target virtual flow velocity or the inverse of the target virtual Mach number, The same is true for “goals”. That is, the relationship between the target basic normalized volumetric efficiency and the inverse of the virtual flow velocity or the inverse of the virtual Mach number or the relationship between the target normalized volumetric efficiency and the inverse of the target virtual flow velocity or the inverse of the target virtual Mach number is generally The present inventor has confirmed through experiments that any type of engine is highly correlated. The meaning of showing high correlation in any model of a general engine is that the characteristics shown in FIGS. 50 (a) and 50 (b) can be commonly used regardless of the engine model. This makes it possible to build a new engine intake model with versatility. For this reason, the engine development period can be significantly shortened by using this versatile intake model.

  Further, in the present embodiment, focusing on the fact that the volumetric efficiency when the throttle valve 21 is fully open is substantially equivalent to the volumetric efficiency from the downstream of the throttle valve 21 to the total stroke volume, the throttle 21 valve (throat portion) The volumetric efficiency ηvwot when the throttle valve is fully open is adopted as the volumetric efficiency representing the efficiency of sucking the downstream intake air into the pump. At this time, the target basic normalized volumetric efficiency is a value obtained by dividing the target basic volumetric efficiency tηv0, which is the target value of volumetric efficiency, by the volumetric efficiency ηvwot when the throttle valve is fully opened (efficiency for sucking air downstream of the throttle valve into the pump). The target basic volumetric efficiency tηv0 can be immediately calculated by multiplying the target basic normalized volumetric efficiency by the volumetric efficiency ηvwot when the throttle valve is fully opened.

  Further, since the target normalized volumetric efficiency is a value obtained by dividing the target volumetric efficiency tηv, which is a target value of volumetric efficiency, by the volumetric efficiency ηvwot when the throttle valve is fully opened (efficiency of sucking air downstream of the throttle valve into the pump), the target volume The target normalized volumetric efficiency can be immediately calculated by dividing the efficiency tηv by the volumetric efficiency ηvwot when the throttle valve is fully opened.

  In JP-A-11-182298, the relationship between the volume flow rate ratio and the opening area per unit displacement of the throttle valve and per engine revolution (AA / (Ne × VOL)) is used twice. What calculates a throttle valve opening is disclosed.

  Here, the opening area per unit displacement of the throttle valve and per engine rotation is a value obtained by dividing the opening area of the throttle valve by the displacement VOL and the engine rotational speed Ne. If you make more, it becomes the following formula.

Throttle valve opening area / (total stroke volume x (engine speed / 120))
= Throttle valve fully open volumetric efficiency / virtual flow velocity (Appendix 14)
Therefore, the opening area per unit displacement of the throttle valve and per engine rotation as referred to in the publication is the reciprocal of the virtual flow velocity of the present invention (however, the volumetric efficiency when the throttle valve is fully open is 1.0), and It is possible to make the volume flow ratio in the publication correspond to the normalized volumetric efficiency of the present invention. Therefore, the characteristics when the vertical axis represents the reciprocal of the opening area per unit displacement of the throttle valve and the engine revolution and the volume flow ratio is plotted on the horizontal axis in the publication are superimposed on the characteristics shown in FIG. As shown in FIG. 51, according to the technique of the publication, there is variation in a region where the virtual flow velocity is large (see the alternate long and short dash line). That is, the technique of this publication corresponds to a case where the volume efficiency ηvwot when the throttle valve is fully opened is always set to 1.0 regardless of the engine speed Ne, but in an actual engine, as shown in FIG. The hourly volumetric efficiency ηvwot may be less than 1.0, and in this case, a deviation from the true normalized volumetric efficiency occurs.

According to a sixteenth embodiment forms state the contrary, since the introduction of the throttle valve fully open when the volumetric efficiency ηvwot which changes according to the engine rotational speed Ne, the throttle valve fully open when the volumetric efficiency ηvwot is less than 1.0 Even in the region, there is no deviation from the true normalized volumetric efficiency.

  The function of the virtual flow velocity / virtual Mach number calculation means for calculating the virtual flow velocity or virtual Mach number according to claim 1 is normalized by the virtual flow velocity / virtual Mach number calculation means 17 of FIG. The function of the ratio / throat intake air density ratio calculating means is performed by the normalized volumetric efficiency calculating means 18 of FIG.

The functions of the virtual flow velocity / virtual Mach number calculating means, the normalized volume efficiency calculating means, and the volume efficiency calculating means according to claim 5 are the functions of the volume efficiency calculating means 11 of FIG. 30, and the functions of the filling efficiency estimated value calculating means are of FIG. The filling efficiency estimation value calculating means 132 of FIG. 30 is used, the function of the filling efficiency detecting means is the filling efficiency detecting means 133 of FIG. 30, and the functions of the ratio / difference calculating means and the closed fault judging means are the EGR valve closing fault judging means 134 of FIG. Each is fulfilled.

The functions of the virtual flow velocity / virtual Mach number calculating means, the normalized volume efficiency calculating means, and the volume efficiency calculating means according to claim 6 are the volume efficiency calculating means 11 of FIG. 36, and the function of the filling efficiency estimated value calculating means is that of FIG. 36, the function of the filling efficiency detection means is the filling efficiency detection means 133 of FIG. 36, and the functions of the ratio / difference calculation means and the open failure determination means are the EGR valve open failure determination means 181 of FIG. Each is fulfilled.

The function of the virtual flow velocity / virtual Mach number calculation means according to claim 7 is calculated by the virtual flow velocity / virtual Mach number calculation means 17 of FIG. The function of the means is performed by the normalized volumetric efficiency calculating means 18 of FIG. 41, the function of the volumetric efficiency means is performed by the multiplying means 19 of FIG. 41, and the function of the flow velocity calculating means is performed by the flow velocity calculating means 185 of FIG. .

The functions of the virtual flow velocity / virtual Mach number calculating means, the normalized volume efficiency calculating means, and the volume efficiency calculating means according to claim 8 are the functions of the volume efficiency calculating means 11 of FIG. 43, and the functions of the filling efficiency estimated value calculating means are of FIG. The function of the fuel supply amount calculation means is performed by the fuel injection pulse width calculation means 191 of FIG.

The functions of the virtual flow velocity / virtual Mach number calculating means, the normalized volume efficiency calculating means, and the volume efficiency calculating means according to claim 9 are the volume efficiency calculating means 11 of FIG. 43, and the function of the filling efficiency estimated value calculating means is that of FIG. 43, the function of the filling efficiency detecting means is performed by the filling efficiency detecting means 133 of FIG. 43, and the function of the abnormality determining means is performed by the air flow meter output abnormality determining means 201 of FIG. .

The functions of the virtual flow velocity / virtual Mach number calculating means, the normalized volume efficiency calculating means, and the volume efficiency calculating means according to claim 13 are the functions of the volume efficiency calculating means 11 of FIG. 46, and the functions of the filling efficiency estimated value calculating means are of FIG. 46, the function of the filling efficiency detection means is performed by the filling efficiency detection means 133 of FIG. 46, and the functions of the time / count measurement means and the abnormality determination means are performed by the air flow meter output abnormality determination means 211 of FIG. The function of the target throttle valve opening calculating means is the throttle valve control by the target throttle valve opening calculating means 212 of FIG. 46, and the function of the target throttle valve opening limiting means is the target throttle valve opening limiting means 213 of FIG. The functions of the means are performed by the actuators 213 shown in FIG.

The block diagram of the volumetric efficiency calculation means of 1st Embodiment of this invention. The characteristic figure of throttle valve opening area. The characteristic diagram of a purge valve opening area. The characteristic figure of volumetric efficiency at the time of throttle valve full open. The characteristic view which shows the relationship between virtual flow velocity or virtual Mach number, normalized volumetric efficiency, throttle valve front-rear intake pressure ratio, throttle valve front-rear intake density ratio. The characteristic view which shows the relationship between virtual flow velocity or virtual Mach number, normalized volumetric efficiency, throttle valve front-rear intake pressure ratio, throttle valve front-rear intake density ratio. The figure which shows the single cylinder model of a multicylinder engine. The block diagram of the engine controller of 2nd Embodiment. The characteristic figure of target filling efficiency. The block diagram of the volume efficiency calculation means at the time of the throttle valve full open of 3rd Embodiment. The characteristic diagram of the optimal intake cam phase. The characteristic diagram of the optimal intake cam phase. The characteristic figure of the volumetric efficiency at the time of normalization throttle valve full open. The characteristic view of intake air temperature change. The characteristic figure of the volumetric efficiency at the time of normalization throttle valve full open. The characteristic figure of the amplitude rate with respect to an engine speed. The wave form diagram which shows the content of an amplitude rate. The characteristic diagram of an intake pulsation correction coefficient. The block diagram of the volume efficiency calculation means at the time of the throttle valve full open of 4th Embodiment. The block diagram of the volume efficiency calculation means at the time of the throttle valve full open of 5th Embodiment. The characteristic figure of the volume efficiency at the time of the 3rd normalization throttle valve full open. The block diagram of the volume efficiency calculation means at the time of the throttle valve full open of 6th Embodiment. FIG. 14 is a characteristic diagram of volume efficiency when the fourth normalized throttle valve is fully opened. The block diagram of the volume efficiency calculation means at the time of throttle valve full open of 7th Embodiment. The characteristic figure of the volume efficiency at the time of a 5th normalization throttle valve full open. The block diagram of the volume efficiency calculation means at the time of throttle valve full open of 8th Embodiment. Schematic which shows the structure of the intake control valve with respect to a 6 cylinder engine. The characteristic graph of the volume efficiency at the time of the 6th normalization throttle valve full open. The block diagram of the volume efficiency calculation means at the time of the throttle valve full open of 9th Embodiment. The block diagram of the engine controller of 10th Embodiment. The block diagram of a filling efficiency detection means. The characteristic view for demonstrating the closing failure of an EGR valve. The characteristic view which shows the relationship of the passing rate with respect to a target EGR rate. The characteristic view for demonstrating the area | region which determines a closed failure. The flowchart for demonstrating EGR valve closing fault determination. The block diagram of the engine controller of 11th Embodiment. The characteristic view for demonstrating the open failure of an EGR valve. The characteristic view which shows the relationship of the passing rate with respect to a target EGR rate. The characteristic view for demonstrating the area | region which determines an open failure. The flowchart for demonstrating EGR valve open failure determination. The block diagram of 12th Embodiment. The characteristic diagram of the flow velocity with respect to the throttle valve front-rear intake pressure ratio (P2 / P1). The block diagram of the engine controller of 13th Embodiment. The block diagram of the engine controller of 14th Embodiment. The waveform diagram for demonstrating the effect | action of 14th Embodiment. The block diagram of the engine controller of 15th Embodiment. The characteristic view which shows the relationship between a throttle-valve opening degree and intake air quantity. The characteristic view which shows the relationship between a virtual flow velocity and a flow velocity. The block diagram of the engine controller of 16th Embodiment. The characteristic view which shows the relationship between the reciprocal number of virtual flow velocity, or the reciprocal number of virtual Mach number, and normalized volumetric efficiency. The characteristic view which shows the relationship between virtual flow velocity and normalized volumetric efficiency. The block diagram of other embodiment. The block diagram of other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Throttle sensor 2 Position sensor 3 Phase sensor 10 Engine controller 21 Throttle valve 22 Intake passage 25 EGR valve (EGR device)
29 Fuel injection valve (fuel supply means)
50 VTC mechanism 141 Air flow meter (filling efficiency detection means)

Claims (16)

In a control device for an engine having a throttle valve in the intake passage and having a function as a pump for sucking intake air downstream of the throttle valve into a combustion chamber,
The value obtained by dividing the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened by the gas substance quantity when the total stroke volume is satisfied with the gas downstream of the throttle valve when the throttle valve is fully opened is when the throttle valve is fully opened. Virtual flow velocity / virtual Mach number for calculating the virtual flow velocity based on the volumetric efficiency and dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area, or the virtual Mach number that is the virtual flow velocity divided by the sound velocity A calculation means;
Based on this calculated virtual flow velocity or virtual Mach number, normalized volumetric efficiency, throttle valve front / rear intake pressure ratio, and normalized volume efficiency / throttle valve front / rear intake pressure ratio are calculated.・ Throttle valve front and rear intake density ratio calculation means,
A volume efficiency calculating means for calculating volume efficiency based on any one of the calculated normalized volume efficiency, throttle valve front-rear intake pressure ratio, and throttle valve front-rear intake density ratio; .   The engine control device according to claim 1, wherein the volumetric efficiency when the throttle valve is fully opened is a value determined by an engine speed. When calculating the normalized volume efficiency based on the calculated virtual flow velocity or virtual Mach number, and calculating the volume efficiency based on the calculated normalized volume efficiency,
The engine control device according to claim 1, wherein a value obtained by multiplying the volumetric efficiency when the throttle valve is fully opened by the normalized volumetric efficiency is calculated as the volumetric efficiency.   The normalized volumetric efficiency / throttle valve front / rear intake pressure ratio / throttle valve front / rear intake density ratio calculation means has a predetermined volume efficiency, the throttle valve front / rear intake pressure ratio, or the throttle valve front / rear intake density ratio. The engine control device according to claim 1, wherein the calculation is performed using a table. In a control device for an engine having a throttle valve in the intake passage and having a function as a pump for sucking intake air downstream of the throttle valve into a combustion chamber,
An EGR device capable of variably controlling the EGR rate;
The value obtained by dividing the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened by the gas substance quantity when the total stroke volume is satisfied with the gas downstream of the throttle valve when the throttle valve is fully opened is when the throttle valve is fully opened. Virtual flow velocity / virtual Mach number for calculating the virtual flow velocity based on the volumetric efficiency and dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area, or the virtual Mach number that is the virtual flow velocity divided by the sound velocity A calculation means;
Based on the calculated virtual flow velocity or virtual Mach number, normalized volume efficiency calculating means for calculating normalized volume efficiency;
Volume efficiency calculating means for calculating the volume efficiency by multiplying the normalized volume efficiency by the volume efficiency when the throttle valve is fully opened;
Filling efficiency estimated value calculating means for calculating a filling efficiency estimated value based on the volume efficiency;
Filling efficiency detecting means for detecting the filling efficiency;
Ratio / difference calculating means for calculating a ratio or difference between the filling efficiency detection value and the filling efficiency estimated value;
Closed failure determination means for determining whether or not the EGR device has a closed failure based on this ratio or difference;
The engine control apparatus, characterized in that it comprises a. In a control device for an engine having a function as a pump that provides a throttle valve in an intake passage and sucks intake air downstream of the throttle valve into a combustion chamber,
An EGR device capable of variably controlling the EGR rate;
The value obtained by dividing the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened by the gas substance quantity when the total stroke volume is satisfied with the gas downstream of the throttle valve when the throttle valve is fully opened is when the throttle valve is fully opened. Virtual flow velocity / virtual Mach number for calculating the virtual flow velocity based on the volumetric efficiency and dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area, or the virtual Mach number that is the virtual flow velocity divided by the sound velocity A calculation means;
Normalized volumetric efficiency calculating means for calculating normalized volumetric efficiency based on the calculated virtual flow velocity or virtual Mach number;
Volume efficiency means for calculating the volume efficiency by multiplying the normalized volume efficiency by the volume efficiency when the throttle valve is fully opened;
Filling efficiency estimated value calculating means for calculating a filling efficiency estimated value based on the volume efficiency;
Filling efficiency detecting means for detecting the filling efficiency;
Ratio / difference calculating means for calculating a ratio or difference between the filling efficiency detection value and the filling efficiency estimated value;
Open failure determination means for determining whether or not the EGR device has an open failure based on the ratio or difference;
Controller features and to Rue engine that comprises a. In a control device for an engine having a function as a pump that provides a throttle valve in an intake passage and sucks intake air downstream of the throttle valve into a combustion chamber,
The value obtained by dividing the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened by the gas substance quantity when the total stroke volume is satisfied with the gas downstream of the throttle valve when the throttle valve is fully opened is when the throttle valve is fully opened. Virtual flow velocity / virtual Mach number for calculating the virtual flow velocity based on the volumetric efficiency and dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area, or the virtual Mach number that is the virtual flow velocity divided by the sound velocity A calculation means;
Normalized volumetric efficiency calculating means for calculating normalized volumetric efficiency based on the calculated virtual flow velocity or virtual Mach number;
Volume efficiency means for calculating the volume efficiency by multiplying the normalized volume efficiency by the volume efficiency when the throttle valve is fully opened;
A flow velocity calculating means for calculating a flow velocity by multiplying the volumetric efficiency by the virtual flow velocity;
Controller features and to Rue engine that comprises a. In a control device for an engine having a function as a pump that provides a throttle valve in an intake passage and sucks intake air downstream of the throttle valve into a combustion chamber,
The value obtained by dividing the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened by the gas substance quantity when the total stroke volume is satisfied with the gas downstream of the throttle valve when the throttle valve is fully opened is when the throttle valve is fully opened. Virtual flow velocity / virtual Mach number for calculating the virtual flow velocity based on the volumetric efficiency and dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area, or the virtual Mach number that is the virtual flow velocity divided by the sound velocity A calculation means;
Normalized volumetric efficiency calculating means for calculating normalized volumetric efficiency based on the calculated virtual flow velocity or virtual Mach number;
Volume efficiency means for calculating the volume efficiency by multiplying the normalized volume efficiency by the volume efficiency when the throttle valve is fully opened;
Filling efficiency estimated value calculating means for calculating a filling efficiency estimated value based on the volume efficiency;
Fuel supply amount calculation means for calculating the fuel supply amount based on the estimated charging efficiency value;
Fuel supply means for supplying the fuel supply amount to the engine;
Controller features and to Rue engine that comprises a. In a control device for an engine having a function as a pump that provides a throttle valve in an intake passage and sucks intake air downstream of the throttle valve into a combustion chamber,
The value obtained by dividing the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened by the gas substance quantity when the total stroke volume is satisfied with the gas downstream of the throttle valve when the throttle valve is fully opened is when the throttle valve is fully opened. Virtual flow velocity / virtual Mach number for calculating the virtual flow velocity based on the volumetric efficiency and dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area, or the virtual Mach number that is the virtual flow velocity divided by the sound velocity A calculation means;
Normalized volumetric efficiency calculating means for calculating normalized volumetric efficiency based on the calculated virtual flow velocity or virtual Mach number;
Volume efficiency means for calculating the volume efficiency by multiplying the normalized volume efficiency by the volume efficiency when the throttle valve is fully opened;
Filling efficiency estimated value calculating means for calculating a filling efficiency estimated value based on the volume efficiency;
An actual filling efficiency detecting means for detecting the filling efficiency;
An abnormality determining means for determining whether or not there is an abnormality in the output of the filling efficiency detection means based on the filling efficiency detection value and the filling efficiency estimation value;
Controller features and to Rue engine that comprises a. The abnormality determining means includes
An abnormality determination value calculating means for calculating a value obtained by adding a predetermined difference or rate to the filling efficiency estimated value as an abnormality determination upper limit value and an abnormality determination lower limit value;
When the filling efficiency detection value exceeds the abnormality determination upper limit value, the abnormality determination upper limit value is set. When the filling efficiency detection value is less than the abnormality determination lower limit value lower limit value, the abnormality determination lower limit value is set. Limiting means to limit;
An abnormality determination unit that determines that the output of the charging efficiency detection unit is abnormal when the state in which the filling efficiency detection value is limited to the abnormality determination upper limit value or the abnormality determination lower limit value continues for a predetermined time or more;
The engine control apparatus according to claim 9, characterized in that it comprises a. A fuel supply amount calculating means for calculating a fuel supply amount based on the filling efficiency detection value; and a fuel supply means for supplying the fuel supply amount to the engine, wherein the filling efficiency detection value is the abnormality determination upper limit value or the The fuel supply is based on the limited charging efficiency detection value when it is limited to the abnormality determination lower limit value, and based on the charging efficiency estimation value when it is determined that the output of the charging efficiency detection means is abnormal. The engine control device according to claim 10 , wherein an amount is calculated . In a control device for an engine having a function as a pump that provides a throttle valve in an intake passage and sucks intake air downstream of the throttle valve into a combustion chamber,
The value obtained by dividing the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened by the gas substance quantity when the total stroke volume is satisfied with the gas downstream of the throttle valve when the throttle valve is fully opened is when the throttle valve is fully opened. Virtual flow velocity / virtual Mach number for calculating the virtual flow velocity based on the volumetric efficiency and dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area, or the virtual Mach number that is the virtual flow velocity divided by the sound velocity A calculation means;
Normalized volumetric efficiency calculating means for calculating normalized volumetric efficiency based on the calculated virtual flow velocity or virtual Mach number;
Volume efficiency means for calculating the volume efficiency by multiplying the normalized volume efficiency by the volume efficiency when the throttle valve is fully opened;
An actual volume efficiency detecting means for detecting the actual volume efficiency;
An abnormality determining means for determining whether or not the output of the actual volume efficiency detecting means is abnormal based on the actual volume efficiency and the calculated volume efficiency;
Controller features and to Rue engine that comprises a. In a control device for an engine having a function as a pump that provides a throttle valve in an intake passage and sucks intake air downstream of the throttle valve into a combustion chamber,
The value obtained by dividing the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened by the gas substance quantity when the total stroke volume is satisfied with the gas downstream of the throttle valve when the throttle valve is fully opened is when the throttle valve is fully opened. Virtual flow velocity / virtual Mach number for calculating the virtual flow velocity based on the volumetric efficiency and dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area, or the virtual Mach number that is the virtual flow velocity divided by the sound velocity A calculation means;
Normalized volumetric efficiency calculating means for calculating normalized volumetric efficiency based on the calculated virtual flow velocity or virtual Mach number;
Volume efficiency means for calculating the volume efficiency by multiplying the normalized volume efficiency by the volume efficiency when the throttle valve is fully opened;
Filling efficiency estimated value calculating means for calculating a filling efficiency estimated value based on the volume efficiency;
An actual filling efficiency detecting means for detecting the filling efficiency;
A time / times measuring means for measuring the time or number of times when the difference or ratio between the filling efficiency detection value and the filling efficiency estimated value exceeds a predetermined value in a region where intake pulsation may occur;
An abnormality determination means for determining whether or not there is an abnormality with a large positive error associated with intake pulsation in the output of the charging efficiency detection means depending on whether or not the measured value exceeds a determination value;
A target throttle valve opening calculating means for calculating a target throttle valve opening according to the accelerator operation amount and the engine speed;
Target throttle valve opening limiting means for limiting the target throttle valve opening to a predetermined value so that intake pulsation does not occur when there is an abnormality in which a positive error associated with intake pulsation is greater than the determination result;
Throttle valve control means for controlling the throttle valve so as to obtain a target throttle valve opening limited to the predetermined value;
Controller features and to Rue engine that comprises a. In a control device for an engine having a function as a pump that provides a throttle valve in an intake passage and sucks intake air downstream of the throttle valve into a combustion chamber,
The value obtained by dividing the cylinder intake fresh air substance amount per cycle when the throttle valve is fully opened by the gas substance quantity when the total stroke volume is satisfied with the gas downstream of the throttle valve when the throttle valve is fully opened is when the throttle valve is fully opened. Virtual flow velocity / virtual Mach number for calculating the virtual flow velocity based on the volumetric efficiency and dividing the volumetric efficiency when the throttle valve is fully opened by the throttle valve opening area, or the virtual Mach number that is the virtual flow velocity divided by the sound velocity A calculation means;
Normalized volumetric efficiency calculating means for calculating normalized volumetric efficiency based on the calculated virtual flow velocity or virtual Mach number;
Volume efficiency means for calculating the volume efficiency by multiplying the normalized volume efficiency by the volume efficiency when the throttle valve is fully opened;
An actual volume efficiency detecting means for detecting the actual volume efficiency;
Means for measuring a time or number of times that a difference or ratio between the actual volume efficiency and the calculated volume efficiency exceeds a predetermined value in a region where intake pulsation may occur;
An abnormality determining means for determining whether or not there is an abnormality with a large plus error associated with intake pulsation in the output of the actual volume efficiency detecting means depending on whether or not the measured value exceeds a determination value;
A target throttle valve opening calculating means for calculating a target throttle valve opening according to the accelerator operation amount and the engine speed;
Target throttle valve opening limiting means for limiting the target throttle valve opening to a predetermined value so that intake pulsation does not occur when there is an abnormality in which a positive error associated with intake pulsation is greater than the determination result;
Throttle valve control means for controlling the throttle valve so as to obtain a target throttle valve opening limited to the predetermined value;
Controller features and to Rue engine that comprises a. The engine control device according to claim 13 or 14 , wherein the predetermined value is set before a saturation region of the intake air amount . The engine control device according to any one of claims 5 to 15, wherein the volumetric efficiency when the throttle valve is fully opened is a value determined by an engine speed .

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