JP4052196B2 - Engine fuel injection amount control device - Google Patents

Description

  The present invention relates to an engine fuel injection amount control device.

A parameter representing the fuel behavior consisting of the wall adhesion rate Rm (k) of the fuel injected by the fuel injection valve and the residual rate Pm (k) of the adhering fuel is variably set based on the degree of change in the intake pressure. There is one in which the fuel injection amount is corrected using a behavior parameter (see Patent Document 1).
JP-A-9-303173

Meanwhile, spray injected from the fuel injection valve flows a liquid state adheres to the wall surface of the intake system and combustion chamber, to form a so-called fuel wall flow, some of this wall flow fuel intake system and combustion Evaporates in the atmosphere of the firing chamber. In addition, part of the wall flow fuel is peeled off and scattered in the air of the combustion chamber, or flows through the wall surface. If basic characteristics related to evaporation of wall flow fuel and scattering and movement of wall flow fuel (hereinafter referred to as “carrying away”) are determined, for example, by changing the layout of the fuel injection valve Even if the amount of evaporation from the wall flow fuel or the amount of carry away from the wall flow fuel varies due to the change in the location of the spray, the amount of evaporation from the wall flow fuel on the wall of the intake system and the wall of the combustion chamber It is possible to calculate the amount of evaporation and the amount of removal using the same basic characteristics even if the amount of removal is different, eliminating the need for re-experimental adaptation, greatly reducing the number of man-hours required for adaptation The period can be shortened.

  Part of the spray during injection is vaporized in the air of the intake system. If the basic characteristics related to this vaporization are determined, even if the amount of vaporization into the air of the intake system differs due to the change to a fuel injection valve with a different particle size of spray during spraying (the nature of the fuel injection valve) Since the vaporization amount for the changed fuel injection valve can be calculated using the same basic characteristics, there is no need for re-experimental adaptation, the adaptation man-hours can be greatly reduced, and the time required for adaptation can be shortened.

  However, the conventional apparatus cannot reduce the man-hours required for the adaptation experiment for each individual engine. That is, in the conventional apparatus, since the adaptation of the wall surface adhesion rate Rm (k) and the adhesion fuel residual rate Pm (k) is experimentally performed, for example, the wall surface adhesion rate Rm (k) If the layout of the fuel injection valve provided in the engine after the adaptation of the fuel residual rate Pm (k) is completed by experiment, the experiment adaptation of the same man-hour is required again even if the engine is the same. Become.

  Therefore, the present invention determines the basic characteristics related to the evaporation and removal of wall flow fuel, so that even if there is a change in the layout of the fuel injection valve or the difference between the wall surface of the intake system and the wall surface of the combustion chamber, By eliminating the need for special maps and tables for the re-conformance experiment and the intake system and the combustion chamber, and by determining the basic characteristics related to the vaporization of the spray during injection, the particle size of the spray during injection (the fuel injection valve Even if there is a change to a fuel injection valve with a different quality), the purpose is to reduce engine development time by eliminating the need for re-adaptation experiments.

The present invention comprises an intake valve that opens and closes an intake port at the inlet of a combustion chamber, and a fuel injection valve that injects fuel into the intake port, and has basic characteristics related to the vaporization of injection spray injected from the fuel injection valve, and Detecting / estimating means for detecting or estimating the temperature of the vaporizing part of the spray at the time of injection, the flow rate of the vaporizing part of the spray at the time of the injection, the speed of the spray due to the penetration force of the spray at the time of injection, and the speed of the intake airflow The speed of the spray is set according to the specifications of the fuel injection valve, and the speed setting / estimating means for estimating the speed of the intake air flow in proportion to the engine speed is detected or estimated. The vaporization amount or vaporization rate of the spray during spraying is calculated from the temperature, the set spray velocity and the estimated intake airflow velocity using the basic characteristics, and the calculated vaporization amount or vaporization rate is used. Configured to calculate a fuel injection amount from the fuel injection valve.

According to the present invention, for example, when a strange Waru where there is direct contact layout of the spray of the fuel injection valve is also vaporization of the injection time of spraying with the same basic characteristics related to vaporization of the injected during spray injected from the fuel injection valve Since the quantity (or vaporization rate) can be calculated, there is no need for a second adaptation experiment, the adaptation man-hours can be greatly reduced, and the time required for adaptation can be shortened .

  Further, according to the present invention, even if the vaporization amount (or vaporization rate) of the spray during injection is different due to the difference in the particle size of the spray during injection, which is a characteristic of the fuel injection valve, the same basic characteristics related to the vaporization of the spray during injection are used. This makes it possible to calculate the amount of vaporization, eliminating the need for a second calibration experiment, greatly reducing the number of calibration steps, and shortening the time required for calibration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram for explaining a system according to an embodiment of the present invention applied to an L-Jetronic gasoline injection engine.

  The air metered by the intake throttle valve 23 is stored in the intake collector 2 and then introduced into the combustion chamber 5 of each cylinder via the intake manifold 3. The engine speed is calculated based on the intake air flow rate detected by the air flow meter 32 and the signal from the crank angle sensor (33, 34) from the fuel injection valve 21 arranged in the intake port 4 of each cylinder. Accordingly, the injection is intermittently supplied into the intake port at a predetermined timing, more specifically, toward the intake valve 15 (back of the umbrella) that exists so as to be blocked by the intake port.

  The fuel injected toward the intake valve 15 is mixed with the intake air to form an air-fuel mixture. The air-fuel mixture is confined in the combustion chamber 5 by closing the intake valve 15, compressed by the rise of the piston 6, and ignited. It is ignited by the plug 14 and burns. The gas pressure due to the combustion works to push down the piston 6, and the reciprocating motion of the piston 6 is converted into the rotational motion of the crankshaft 7. The combusted gas (exhaust gas) is discharged into the exhaust passage 8 when the exhaust valve 16 is opened.

A three-way catalyst 9 is provided in the exhaust passage 8. The three-way catalyst 9 can efficiently remove HC, CO and NOx contained in the exhaust gas simultaneously when the air-fuel ratio of the exhaust gas is in a narrow range centered on the stoichiometric air-fuel ratio. For this reason, the engine controller 31 determines the basic fuel injection amount from the fuel injection valve 21 according to the operating conditions, and based on the signal from an O ₂ sensor (not shown) provided upstream of the three-way catalyst 9. Feedback control.

  The intake throttle valve 23 is driven by a throttle motor 24. Since the torque required by the driver appears in the amount of depression of the accelerator pedal 41 (accelerator opening), the engine controller 31 determines a target torque based on a signal from the accelerator sensor 42, and a target air for realizing this target torque. The amount is determined, and the opening degree of the intake throttle valve 23 is controlled via the throttle motor 24 so that this target air amount is obtained.

  Also, mainly for improving fuel efficiency, an EGR device (comprising an EGR passage 25, an EGR valve 26, and an actuator 27) and a VTC mechanism (valve timing control mechanism) 29 as a kind of intake valve operating angle variable mechanism are provided. .

  Now, on the premise of an L-Jetronic gasoline injection engine, in this embodiment, combustion prediction type control is performed. Specifically, the wall flow fuel and unburned fuel in the intake port 4 and the combustion chamber 5 are estimated using temperature as a main parameter, and the result is applied to fuel injection control.

  First, the results of reviewing the behavior of the fuel until the fuel injected from the injection valve 21 is combusted are shown in FIGS. In FIG. 2, the broken line indicates that the fuel injected from the injection valve 21 moves in a gaseous state, and the solid line indicates that the fuel moves in a sprayed state. In addition, since the fine thing (fine spray) can be handled in the same manner as gas, it is classified into gas. In this case, it is assumed that the gas and fine particle spray do not adhere to the intake port and the combustion chamber again.

  Here, the fuel behavior up to the combustion chamber inlet and the fuel behavior in the combustion chamber are roughly divided.

(1) Fuel behavior to the combustion chamber inlet:
The fuel injected from the injection valve 21 to the intake port 4 is largely branched into a portion that is vaporized to become gas (a gas) and a portion that floats while being sprayed. The fuel that has become the gas and the fine atom spray is sucked into the combustion chamber 5 without adhering to the port wall 4a and the intake valve umbrella back portion 15a. A part of the fuel drifting while sprayed is carried by the air flow and directly sucked into the combustion chamber 5, and the rest adheres to the intake valve umbrella back 15a and the intake port wall 4a.

  Here, the wall flow formed by adhering to the intake valve 15 is formed not only on the umbrella back portion 15 a but also on the surface 15 b of the intake valve 15 facing the combustion chamber 5. Since the wall flow formed on the combustion chamber side surface 15b is handled by the wall flow formed in the combustion chamber 5, only the wall surface of the umbrella back portion 15a of the intake valve 15 is defined as an “intake valve wall” below. To do.

  The fuel adhering to the port wall 4a and the intake valve wall 15a forms a wall flow. In this case, the wall temperature is largely different in each wall (same after cold start, but the temperature of the intake valve wall becomes higher than the temperature of the port wall as the engine warms up) Since the fuel evaporates with different characteristics from the wall flow, the wall flow is also treated separately.

  Each of these wall flows is partially converted into gas upon receiving the result of the physical quantity that is easy to evaporate, such as the wall temperature, and the remainder is sucked into the combustion chamber 5 and is separated from the wall flow by the flow of intake air or gravity to become spray. Or it flows in the combustion chamber 5 along each wall part as wall flow.

(2) fuel behavior in a combustion chamber:
In this way, the fuel group sucked into the combustion chamber 5 through various circumstances contributes directly to combustion as a gas and fine spray, and a part forms a wall flow in the combustion chamber 5. The wall flow in the combustion chamber 5 is actually connected to the combustion chamber side surface 15b of the intake valve 15, the combustion chamber side surface of the exhaust valve 16 (not shown in FIGS. 2 and 3), and the intake port 4a. The cylinder head wall 51, the piston crown surface 6a, the spark plug surface (not shown), and the cylinder surface wall 52 are present everywhere. Part of the wall flow in the combustion chamber 5 is evaporated and vaporized by compression heat or wall heat until combustion by ignition, and becomes a gas or fine particle spray, contributing to combustion, and partly after the combustion is completed It is evaporated and discharged to the exhaust passage 8 in the exhaust stroke without contributing to combustion. In particular, the fuel that forms the wall flow of the cylinder face wall 52 escapes to the crankcase while being partially diluted with oil, and is contained in the blow-by gas.

  Here, the part where the wall flow is formed in the combustion chamber 5 is divided into the cylinder face wall 52 and the other combustion chamber walls.

  Here, the combustion chamber walls other than the cylinder surface wall 52 are defined as “combustion chamber walls”. In general, the term “combustion chamber wall” is confusing because it includes the cylinder surface wall. However, since no other appropriate expression is found, the present embodiment uses the “combustion chamber wall” as a concept excluding the cylinder surface wall 52. The combustion chamber wall includes a combustion chamber side surface 15b of the intake valve.

  There is a large wall temperature difference between the two walls, the combustion chamber wall and the cylinder face wall 52 (since the cylinder formed in the cylinder block is cooled by the cooling water flowing through the water jacket in the cylinder block, Since the temperature of the cylinder face wall 52 changes at a temperature substantially equal to the water temperature, the temperature of the combustion chamber wall is higher than the temperature of the cylinder face wall 52), and the fuel evaporation characteristics from each wall flow are greatly different. This is to facilitate adaptation.

  However, the number to be divided is not limited to two. More specifically, the combustion chamber wall is composed of the combustion chamber side surface 15b of the intake valve 15, the combustion chamber side surface of the exhaust valve 16, the cylinder head wall 51, the piston crown surface 6a, the spark plug surface, etc., as described above. There is also a large wall temperature difference. That is, the temperature of the combustion chamber side surface of the exhaust valve 16 is the highest, the combustion chamber side surface 15b of the intake valve and the piston crown surface 6a are substantially the same temperature, and the combustion chamber side surface 15b and piston crown surface 6a of these intake valves. Is higher than the temperature of the cylinder head wall 51. Therefore, it is conceivable to further divide the combustion chamber wall into two or more for each wall temperature (for example, to divide the combustion chamber wall into a high temperature combustion chamber wall and a low temperature combustion chamber wall).

  In this way, the wall flow formed in the combustion chamber 5 due to the difference in wall temperature is divided into two (combustion chamber wall flow and cylinder face wall flow), and the fuel in the combustion chamber 5 contributes to combustion. These can be organized as follows if they are divided into three parts that are discharged unburned and ones that are diluted with oil.

[1] Fuel contributing to combustion:
This is (a) fuel immediately after being injected from the injection valve 21 and fuel that has become a fine spray, (b) fuel that has evaporated from the spray sucked into the combustion chamber 5 and has become a fine spray, (c) Fuel evaporating from the port wall flow into gas and fine spray, (d) Fuel evaporating from the intake valve wall flow into gas and fine spray, (e) Between combustion chamber wall flow and combustion by ignition (F) The fuel that has evaporated to become gas and fine atomized spray, and (f) The fuel that has evaporated to gas and finely atomized fuel from the cylinder face wall flow to the combustion by ignition.

[2] Fuel discharged unburned:
This is because (g) the fuel is evaporated after the combustion is completed from the combustion chamber wall flow to become gas and fine particle spray, and is discharged into the exhaust passage 8 in the exhaust stroke, and (h) the combustion is completed from the cylinder surface wall flow Then, it is the total of the fuel that evaporates to become gas and fine particle spray and is discharged into the exhaust passage 8 in the exhaust stroke.

[3] Oil dropping fuel:
This is (i) fuel contained in the blow-by gas that escapes to the crankcase while being diluted with oil from the cylinder face wall flow.

  Based on the analysis results of the fuel behavior shown in FIGS. 2 and 3, four wall flows (port wall flow, intake valve wall flow, combustion chamber wall flow, cylinder face wall flow) are modeled as shown in FIG. To create a mixture model of ports and combustion chambers per cylinder. That is, as shown in FIG. 4, the mixture model is converted into a fuel injection amount calculation means 51, a fuel branching ratio calculation means 52, four fuel adhesion amount calculation means (intake valve wall adhesion amount calculation means 53, port wall adhesion amount calculation). Means 54, combustion chamber wall adhesion amount calculation means 55, cylinder face wall adhesion amount calculation means 56), combustion fuel calculation means 57, unburned fuel calculation means 58, oil drop amount calculation means 59, and exhaust fuel calculation means 60. To do.

  First, in the intake valve wall adhesion amount calculation means 53 and the port wall adhesion amount calculation means 54, it is assumed that each wall flow rate (fuel adhesion amount) changes every injection (= each intake stroke), that is, every combustion cycle. Once per cycle, the intake valve wall adhesion amount Mfv and the port wall adhesion amount Mfp are calculated using the following recurrence formula.

Mfv = Mfv _n-1 + Fin · X1
-Mfv _n-1 (Y0 + Y1 + Y2) (1)
Mfp = Mfp _n-1 + Fin · X2
-Mfp _n-1 (Z0 + Z1 + Z2) (2)
Where Mfv: Intake valve wall adhesion amount,
Mfv _n-1 : Value of Mfv before one combustion cycle,
Mfp: Port wall adhesion amount,
Mfp _n-1 : The value of Mfp before one combustion cycle,
Fin: Fuel injection amount,
Xn, Yn, Zn: Fuel split ratio of each part,
Here, the above equation (1) adds the fuel amount (the second term on the right side) that increases as a wall flow due to the current injection to Mfv _n−1 , which is the intake valve wall adhesion amount before one combustion cycle. This subtracts the amount of fuel that has been reduced up to the current injection (third term, fourth term, and fifth term on the right side). That is, Fin · X1 in the second term on the right side is a fuel component that changes to the intake valve wall flow in the current fuel injection amount Fin. Mfv _n−1 · Y0 in the third term on the right-hand side is a portion of Mfv _n−1 that is evaporated by the current injection to become a gas and fine particle spray and is directly sucked into the combustion chamber 5 and combusted. Mfv _n−1 · Y1 in the fourth term on the right side is the fuel component of Mfv _{n−1 that} is peeled off before the current injection and becomes sprayed or flows as a wall flow and becomes a combustion chamber wall flow, Mfv _{n −1} · Y2 is a fuel component of Mfv _{n−1 that} is peeled off by the current injection and becomes sprayed or flows in a wall flow and becomes a cylinder wall flow.

The above expression (2) is the same as the above expression (1). That is, Fin · X2 in the second term on the right side is a fuel component that changes to the port wall flow in the current fuel injection amount. Mfp _n−1 · Z0 in the third term on the right-hand side is a portion of Mfp _n−1 that is evaporated by the current injection to become a gas or fine particle spray and is directly sucked into the combustion chamber 5 and combusted. Mfp _n-1 · Z1 in the fourth term on the right side is the fuel component of Mfp _{n-1 that} is peeled off by spraying until the current injection and becomes sprayed or flows as a wall flow and becomes a combustion chamber wall flow. Mfp _n-1 · Z2 of paragraph 5 are fuel distribution as a cylinder wall flow flows remain in or wall flow after a spraying peeled until this injection of Mfp _n-1.

  The combustion chamber wall adhesion amount calculating means 55 and the cylinder surface wall adhesion amount calculating means 56 also assume that each fuel adhesion amount changes for each injection, that is, for each combustion cycle, and once per combustion cycle, the following recurrence formula is used. Using this, the combustion chamber wall adhesion amount Cfh and the cylinder wall adhesion amount Cfc are calculated.

Cfh = Cfh _n-1 + Fin · X3
+ Mfv · Y1 + Mfp · Z1
-Cfh _n-1 (V0 + V1) (3)
Cfc = Cfc _n-1 + Fin · X4
+ Mfv · Y2 + Mfp · Z2
-Cfc _n-1 (W0 + W1 + W2) (4)
Where Cfh: Attached amount of combustion chamber wall,
Cfh _n-1 : Value of Cfh before one combustion cycle,
Cfc: Cylinder surface wall adhesion amount,
Cfc _n-1 : Value of Cfc before one combustion cycle,
Fin: Fuel injection amount,
Xn, Yn, Zn, Vn, Wn: fuel split ratio of each part,
In the above equation (3), Fin · X3 in the second term on the right-hand side is the amount of fuel that changes to the combustion chamber wall flow in the current fuel injection amount Fin. Mfv · Y1 and Mfp · Z1 in the third and fourth terms on the right-hand side are fuel components that are separated from Mfv and Mfp to form spray or flow as a wall flow or change into a combustion chamber wall flow. Cfh _n-1 · V0 in the fifth term on the right side is a fuel component of Cfh _n-1 that has evaporated and vaporized by compression heat, wall heat, etc. until combustion by ignition, and contributed to the combustion. _n−1 · V1 is a fuel component of Cfh _n−1 which is evaporated after combustion is completed and discharged in the exhaust stroke without contributing to combustion.

The above expression (4) is the same as the above expression (3) except for Cfc _n−1 · W2 in the seventh term on the right side. That is, Fin · X4 in the second term on the right side is a fuel component that changes to a cylinder face wall flow in the current fuel injection amount. This is a fuel component that changes into a cylinder face wall flow after being separated from Mfv and Mfp of Mfv and Y2, and Mfp and Zfp in the right and third sections, respectively, and sprayed or sprayed as a wall flow. Cfc _n-1 · W0 in the fifth term on the right side is the fuel component of Cfc _n-1 that has evaporated and vaporized by compression heat, wall heat, etc. before combustion by ignition and contributed to the combustion, and Cfc in the right side sixth term _n−1 · W1 is a portion of Cfc _n−1 that is evaporated after combustion is completed and discharged in the exhaust stroke without contributing to combustion. Cfc _n−1 · W2 in the seventh term on the right side is the amount of fuel contained in the blow-by gas that escapes to the crankcase while being diluted with oil in Cfc _n−1 .

  Note that FIG. 4 is a model as a whole, but it is also a model as a part. That is, the equation (1) is an intake valve wall flow model, the equation (2) is a port wall flow model, the equation (3) is a combustion chamber wall flow model, and the equation (4) is a cylinder wall flow model. It is. It is also a model that the fuel injection amount Fin is divided into X0 to X4.

  The burned fuel calculating means 57, the unburned fuel calculating means 58, and the oil drop amount calculating means 59 respectively calculate the burned fuel Fcom, the unburned fuel Fac, and the oil drop amount Foil by the following equations.

Fcom = Fin · X0 + Mfv · Y0 + Mfp · Z0 + Cfh · V0
+ Cfc · W0 (5)
Fac = Cfh · V1 + Cfc · W1 (6)
Foil = Cfc · W2 (7)
Here, (5) represents the sum of the fuels (a) to (f) above as the burned fuel Fcom, and (6) represents the sum of the fuels (g) and (h) above as the unburned fuel Fac. (7) is a formula (model) obtained by formulating the fuel (i) as an oil drop amount Foil.

  The exhaust fuel calculation means 60 calculates the sum of the burned fuel Fcom and the unburned fuel Fac as exhaust fuel Fout that affects the exhaust as in the following equation.

Fout = Fcom + Fac (8)
Expression (8) represents that all the gas in the combustion chamber 5 is discharged into the exhaust passage 8 for both the burned portion and the unburned portion. In practice, some of the gas remains in the combustion chamber 5 without being discharged into the exhaust passage 8, but this residual gas is not considered in the mixture model shown in FIG.

  The calculation timings of these four calculation units 57 to 60 are the same as those of the fuel adhesion amount calculation units 53 to 56.

  In this way, the above formulas (1) to (8) were obtained. Representative values among these formulas are shown in FIG.

  Next, FIG. 5 is a diagram showing a data flow for calculating Ti for the fuel injection amount for each cylinder using the air-fuel mixture model shown in FIG.

  First, the performance request determination means 71 determines whether there is an exhaust request from the three-way catalyst 9 or an output request (or a stability request) based on the operating conditions. For example, the region where combustion is difficult to stabilize immediately after the cold start is when there is a stability request, and the full load region is when there is an output request. Further, there is a request for exhaust from the three-way catalyst 9 after the activation of the catalyst.

  In the target equivalence ratio determining means 72, the exhaust request equivalence ratio Tfbye (= 1.0) is obtained when there is an exhaust request from the determination result, and the output request equivalence ratio Tfbyp (1. 1 to 1.2 and a fixed value) is determined as the target equivalent ratio Tfbya.

  Here, the equivalent ratio is a value obtained by dividing the theoretical air-fuel ratio (≈14.7) by the air-fuel ratio. Therefore, when the equivalence ratio = 1.0, the air-fuel ratio becomes the stoichiometric air-fuel ratio, and when the equivalence ratio = 1.1 to 1.2, the air-fuel ratio becomes a richer value than the stoichiometric air-fuel ratio.

  In the required injection amount calculation means 75, the target equivalent ratio Tfbya determined in this way and the determination result of the performance request determination means 71, each part adhesion amount calculation means 73, each part fuel branching ratio calculation means 74 (each part of FIG. 4). ) To calculate the required injection amount Fin according to the following equation.

(1) When there is an output request (or stability request);
Fin = {K # · Tfbya · Tp− (Mfv · Y0 + Mfp · Z0
+ Cfh · V0 + Cfc · W0) / X0 (9)
(2) When there is an exhaust request;
Fin = {K # · Tfbya · Tp− (Mfv · Y0 + Mfp · Z0
+ Cfh · V0 + Cfc · W0 + Cfh · V1 + Cfc · W1)}
/ X0 (10)
Here, the expression (9) indicates that when there is an output request or a stability request, the cylinder intake air amount (Qcyl) and the fuel (Fin · X0 + Mfv · Y0 + Mfp · Z0 + Cfh ·) for the three combustion components (X0, Y0 + Z0, V0 + W0). This is an equation for calculating the required injection amount Fin so that the ratio of (V0 + Cfc · W0) is a richer value than the stoichiometric air-fuel ratio. On the other hand, the expression (10) indicates that when there is an exhaust request from the three-way catalyst 9, the cylinder intake air amount (Qcyl) and the fuel (Fin · X0 + Mfv · Y0 + Mfp ·) of the three combustion components (X0, Y0 + Z0, V0 + W0). Z0 + Cfh · V0 + Cfc · W0) and an unburnt amount (V1 + W1) of fuel (Cfh · V1 + Cfc · W1) are calculated to calculate the fuel injection amount from the fuel injection valve 21 so that the ratio becomes the stoichiometric air-fuel ratio. .

  The formula (10) is different from the formula (9) only in that the unburned fuel Fac (= Cfh · V1 + Cfc · W1) is added. This is because it is necessary to consider unburned fuel when considering the air-fuel ratio in the exhaust gas. On the contrary, unburned fuel does not contribute to the output and must be removed.

  As a representative example of equation (9), equation (9) is derived from the following equation.

K # · Tfbya · Tp = Fin · X0
+ (Mfv · Y0 + Mfp · Z0 + Cfh · V0 + Cfc · W0)
... (11)
Where K #: constant,
Tp: basic injection amount obtained from the air flow meter 32,
In the equation (11), the sum of the fuel component (right side first term) and the fuel component (right side second term to fifth term) lost to the fuel and the fuel wall flow is equal to the injected fuel amount on the left side. Represents that. If this formula is arranged for Fin, the above formula (9) is obtained.

  Here, since the basic fuel injection amount Tp on the left side of the equation (11) is a value per cylinder, each value of Fin, Mfv, Mfp, Cfh, and Cfc on the right side is also a value per cylinder. Since the actual unit of the basic fuel injection amount Tp is not [mg], which is a unit of mass, but is [ms], which is a unit of time, for each value of Fin, Mfv, Mfp, Cfh, Cfc on the right side, the unit Is defined in [ms], the constant K # may be 1.0. The unit of Fin, Mfv, Mfp, Cfh, and Cfc may be defined in [mg]. However, at this time, the constant K # is introduced as a conversion coefficient from [ms] to [mg].

  The final injection amount calculation means 76 calculates the final injection amount Ti [ms] at the time of sequential injection using one of the following formulas using the calculated required injection amount Fin [ms].

Ti = Fin × α × αm × 2 + Ts (12a)
Ti = Fin × (α + αm−1) × 2 + Ts (12b)
Where α: air-fuel ratio feedback correction coefficient,
αm: Air-fuel ratio learning correction coefficient,
Ts: Invalid pulse width,
These formulas for the final injection amount Ti are different from the conventional calculation formulas for the fuel injection amount Ti [ms] in an L-Jetronic gasoline injection engine. Incidentally, the calculation formula (at the time of sequential injection) is as follows.

Ti = (Tp + Kathos) × TFBYA × (α + αm−1) × 2
+ CHOSn + Ts (13)
TFBYA = 1 + KTW + KAS + KUB + KMR (14)
However, TFBYA: target equivalent ratio of the conventional apparatus,
Kathos: Wall flow correction amount (slow response),
CHOSn: Wall flow correction amount (fast response),
KTW: Water temperature increase correction coefficient,
KAS: Increase correction coefficient after start,
KUB: Unburnt correction factor,
KMR: mixture correction coefficient,
In the conventional arithmetic expressions shown in the equations (13) and (14), as can be seen from the fact that there are many increase correction coefficients, the combustion is unstable at the time of low water temperature, immediately after the cold start, the unburned portion, and the full load. Independent acceleration correction coefficients (KTW, KAS, KUB, KMR, Kathos, CHOSn) were introduced for each of acceleration and deceleration. However, with such a method, the number of man-hours for adaptation must be dramatically increased in accordance with the number of increase correction coefficients. In addition, the fuel behavior is not analyzed for the compatibility of KTW, KAS, and KUB.

  On the other hand, when all fuel increases are considered in total, they all relate to wall flow fuel. Therefore, the behavior of the fuel until the fuel injected from the injection valve 21 is combusted again as shown in FIGS. 2 and 3 is reviewed, and the mixture model and the fuel are used as shown in FIGS. According to the present embodiment in which the injection amount calculation model is constructed, the KTW, KAS, KUB, and KMR correction coefficients are not necessary. Further, instead of Kathos and CHOSn, four adhesion amounts Mfv, Mfp, Cfh, and Cfc are replaced. That is, according to the present embodiment using any one of the above formulas (1) to (10) and (12a) and (12b), the gasoline injection engine using the conventional arithmetic expressions (13) and (14) The following effects are obtained.

  Effect 1: The air-fuel ratio control accuracy is improved particularly during low-temperature start-up and warm-up. By improving the control accuracy, exhaust performance is improved and startability and drivability (torque accuracy) are improved.

  Effect 2: Analyzing wall flow behavior in the intake port and combustion chamber (all fuel behavior from injection to combustion) facilitates desktop adaptation and reduces the number of man-hours required for adaptation.

  Effect 3: As a result of precisely analyzing the wall flow behavior and injecting fuel in this way, if the air / fuel ratio still deviates from the target, it is related to the accuracy of parts such as the injection valve and air flow meter. Since the judgment can be made, the quality of the engine itself can be improved by feeding back the control result to the air-fuel ratio control.

  By the way, the determination method by the performance request determination means 71 is not limited to this. When the output is requested (or when the stability is requested) and when the exhaust is requested or vice versa, the required injection amount of the equation (9) is switched stepwise to the required injection amount of the equation (10) or At the time of switching to the opposite, if the step injection is switched from the required injection amount of the equation (10) to the required injection amount of the equation (9), a torque step is generated, which causes discomfort or a change in sound quality due to a torque shock. It is done.

  Therefore, the required ratio between the output request and the exhaust request is set according to at least one of the time from the low temperature start, the accelerator opening, and the temperature of the three-way catalyst 9, and the above-mentioned formulas (9) and (10) are set based on this required ratio. The two required injection amounts are interpolated and calculated again as the required injection amount, so that the two required injection amounts are smoothly connected according to the required ratio and stepped between the two required injection amounts. To prevent discomfort or change in sound quality due to torque shock that occurs when switching to.

  To explain this, the ratio between the exhaust request and the output request is defined by the required frequency (request ratio). Here, the required frequency when responding only to the output request is 100%, the required frequency when responding only to the exhaust request is 0%, and the required frequency according to the operating conditions at that time is set. Specifically, it is an output request because combustion in the combustion chamber is difficult to stabilize immediately after the cold start. It is necessary to meet the output demand even in the full load range. Further, after the catalyst 9 provided in the exhaust passage 8 is activated, it is necessary to meet the exhaust request. For these requests, the requested frequency is set as shown in FIGS. That is, as shown in FIG. 6, the initial value is set to 100%, the output request immediately after the low temperature start is met, and the required frequency is reduced as the post-start time (or wall temperature) elapses, thereby changing the output request to the exhaust request. Switch gently. As shown in FIG. 7, the required power is increased in the vicinity of the accelerator pedal 41 being depressed to the maximum to meet the output demand in the full load region. As shown in FIG. 8, the initial value is set to 100%, and the required frequency is decreased as the catalyst temperature increases, so that the output request is gradually switched to the exhaust request.

  In this way, after obtaining the three required frequencies by referring to the tables shown in FIGS. 6, 7, and 8 from the time after starting, the accelerator opening, and the catalyst temperature, of these three required frequencies. Select the largest value.

  Then, the required injection amount Fin in the equation (10) is distinguished as Fin1 (first fuel injection amount), and the required injection amount Fin in the equation (9) is distinguished as Fin2 (first fuel injection amount). A value obtained by interpolating these two required injection amounts Fin1 and Fin2 with the required frequency is calculated as the required injection amount Fin.

Fin = Fin2 × request frequency + Fin1 × (1−request frequency)
... (15)
According to the equation (15), Fin = Fin2 when the required frequency = 100%, and Fin = Fin1 when the required frequency = 0%.

  Here, the post-start time is measured by a timer that starts at the engine start timing. The accelerator opening is detected by the accelerator sensor 42. The catalyst temperature is detected by a catalyst temperature sensor 43.

  Next, each part fuel branching ratio calculating means 52 in FIG. 4 calculates the branching ratio of each part fuel (Fin, Mfv, Mfp, Cfh, Cfc). The calculation of the branching ratio of each part fuel will be described below. As can be seen from the above formulas (1) to (7), (10), and (11), in this embodiment, the fuel branching ratios Xn, Yn, Zn, Vn, and Wn are appropriate values. And the air-fuel ratio control accuracy can be improved by adapting these with high accuracy.

  Here, among L-Jetronic type gasoline injection engines, all engines having a standard system (to be described later) are considered, and therefore, those that perform intake stroke injection and assist air type fuel injection valves are provided. , Those that perform stratified combustion, and those that have a swirl control valve are included, but those that do not fall under the applicable engine may be cut.

  Here, the “standard system” gasoline injection engine satisfies the following two conditions.

  (A) Provide an intake valve in the intake passage.

  (A) The variable valve mechanism is not provided, or the variable valve has a small variable margin even if it is provided.

  Since the present embodiment satisfies both the conditions (a) and (b), it is a standard system gasoline injection engine. On the other hand, an engine that does not have an intake throttle valve and adjusts an intake air flow rate only by the intake valve, an engine that has an electromagnetically driven intake valve, and an engine with a variable compression ratio are not standard gasoline injection engines. Therefore, these engines are out of scope.

  Now, a branching model of the injection valve spray is constructed as shown in FIG. That is, the model is assigned to the spray particle size distribution calculating means 41, the injection-time vaporization ratio calculating means 42, the skip missing ratio calculating means 43, the intake system floating ratio calculating means 44, the combustion chamber floating ratio calculating means 45, and the intake system adhesion ratio allocation. It comprises means 46, combustion chamber adhesion ratio allocation means 47, and vaporization / floating ratio calculation means 48.

  First, the spray particle size distribution calculating means 41 reads the spray particle size distribution stored in advance in the ROM in the engine controller 31. Here, the particle size distribution of the spray is a matrix of the mass ratio of the spray for each small particle size classification (for each particle size), and the calculation of the spray particle size distribution is performed from the ROM in the engine controller 31. This is an operation to read out a matrix of the mass ratio of the spray for each small section of the particle size.

  The injection vaporization rate calculating means 42 calculates the spray vaporization rate for each of the small particle size categories from the signals such as temperature, pressure, flow velocity, etc., and sums up these for all the particle size categories to obtain the total during injection. Vaporization amount X0 '[%] during injection, which is the amount of vaporization from the spray, is calculated. As a result, the spray XB [%] of 100-X0 ′ remains in the intake port 4 without being vaporized.

  The direct injection ratio calculation means 43 receives this residual spray amount XB (= 100−X0 ′) from the injection-time vaporization ratio calculation means 42, and this, injection timing I / T, and the sandwiching between the injection valve 21 and the intake valve 15. Using the angle β, a spray fraction XD [%] that is directly injected into the combustion chamber 5 without colliding with the intake valve 15 or the intake port 4 is calculated. As a result, XB-XD spray XC [%] remains in the intake port 4. The spray XC remaining in the intake port 4 is output to the intake system floating ratio calculating means 44, and the spray XD directly injected into the combustion chamber 5 is output to the combustion chamber floating ratio calculating means 45.

  The intake system floating ratio calculating means 44 calculates the vaporization rate of the spray for each of the small particle size divisions, and sums up these for all the particle size divisions, so that the floating portion X0 ″ [%] at the intake port 4 is obtained. And the remainder of the spray that adheres to the intake port wall 4a and the intake valve wall 15a (hereinafter, the spray that adheres to the intake port wall 4a and the spray that adheres to the intake valve wall 15a are collectively referred to as “intake system”. Calculated as “attachment”) XE (= XC−X0 ″) [%].

  Similarly, the combustion chamber floating ratio calculation means 45 calculates the vaporization rate of the spray for each of the small particle size divisions, and sums these for all the particle size divisions, so that the floating content X0 ″ in the combustion chamber 5 is obtained. ′ [%] And the remainder adhere to the combustion chamber wall (excluding the cylinder surface wall as described above) and the cylinder surface wall 52 (hereinafter referred to as the spray component adhering to the combustion chamber wall and the cylinder surface wall 52). The amount of spray is collectively referred to as “combustion chamber deposit.”) Calculated as XF (= XD−X0 ′ ″) [%].

  The vaporization / floating ratio calculation means 48 adds up the three of the vaporization amount X0 ′ during injection, the floating portion X0 ″ at the intake port 4 and the floating portion X0 ″ ″ obtained in this manner. The vaporization and floating part X0 in one injection total are calculated.

  On the other hand, in the intake system adhesion ratio allocating means 46, the intake system adhesion part XE is divided into the part X1 [%] attached to the intake valve wall 15a and the part X2 [%] attached to the port wall 4a, and the combustion chamber adhesion ratio. The allocating means 47 allocates the combustion chamber adhering amount XF to an amount X3 [%] adhering to the combustion chamber wall and an amount X4 [%] adhering to the cylinder surface wall 52.

Next, a description will be given for the model identification of spray branching.
<1> Spray branch model identification (spray branch overall process)
FIG. 10 shows the process of the entire spray branch used for estimation (identification) of each branch of spray (X0, X1, X2, X3, X4) as a model, and illustrates the branch of fuel spray from the time of injection. As shown in FIG.

1) Vaporization during injection:
An injection spray is a collection of fuel sprays having different particle sizes. Therefore, when the particle diameter D [μm] is taken on the horizontal axis and the mass ratio [%] of the spray is taken on the vertical axis, there is a mountain-shaped distribution (XA) with respect to the particle diameter D as shown in the upper left corner of FIG. However, the area surrounded by the chevron curve is 100%, which is the total sum of the total spray during injection. A part of the fuel spray having a mountain-shaped distribution is vaporized at the time of injection, and the rest stays in the spray. Since the spray having a smaller particle size is more easily vaporized, the distribution of the spray remaining without being vaporized (see the thin solid line) is smaller on the side having a smaller particle size than the spray distribution during spraying (XA). The area between these two distributions is a spray X0 ′ [%] that is vaporized at the time of injection, and 100-X0 ′ is a spray XB [%] that remains without being vaporized.

2) Injection spray directly into the combustion chamber:
In the second characteristic from the upper left of FIG. 10, the large mountain (see thick solid line) is the distribution of the spray spray remaining in the intake port 4 without being vaporized, and of this, the spray directly injected into the combustion chamber 5 The distribution is drawn over small mountains (see thin solid lines). This small mountain area is the spray amount XD [%] directly injected into the combustion chamber 5, and XB-XD, that is, the spray portion XC [%] where the area between the large mountain and the small mountain remains in the intake system. It is.

3) Inhalation system spray adhesion floating:
Part of the spray that is not directly injected into the combustion chamber 5 and remains in the intake port (intake system) floats as it is (including vaporization), and the rest is the wall surface of the intake system (port wall 4a and intake air). It adheres to the valve wall 15a). Since the spray with a smaller particle size is more likely to float as it is, the distribution of the spray adhering to the wall surface of the intake system (see the thin solid line) in the second characteristic from the upper right in FIG. The smaller side of the particle size is smaller than the solid line). The area between these two distributions is the amount that floats as it is sprayed in the intake system (the air floating rate in the intake system) X0 ″ [%], and this floating from the spray amount XB remaining in the intake system. The value obtained by subtracting the minute X0 ″ is the intake system attachment XE (intake system attachment ratio) [%].

4) Combustion chamber spray adhesion floating:
A part of the spray directly injected into the combustion chamber 5 floats in the combustion chamber 5 as a spray (including the portion to be vaporized), and the rest adheres to the combustion chamber wall and the cylinder surface wall 52. Since the spray having a smaller particle size is more likely to float as it is sprayed, the distribution of the spray adhering to the combustion chamber wall and the cylinder surface wall 52 (see the thin solid line) in the second characteristic from the lower right in FIG. The smaller particle size side is smaller than the distribution of spray (see thick line). The area between these two distributions is the amount that floats in the combustion chamber 5 while being sprayed (the air floating ratio in the combustion chamber 5) X0 ″ ″ [%], and is directly injected into the combustion chamber 5 A value obtained by subtracting the floating portion X0 ″ from the sprayed portion XD is the combustion chamber wall deposit (combustion chamber deposit ratio) XF [%].

5) Intake system spray attachment location:
In the characteristic at the upper right end of FIG. 10, the large mountain (see thick solid line) is the XE distribution of the intake system adhering, and the small mountain (see thin solid line) is the distribution of the spray adhering to the intake valve wall 15a. The area of this small peak is the spray X1 [%] adhering to the intake valve wall 15a, and the value obtained by subtracting this intake valve wall X1 from the intake system adhesion XE is the port wall X2 [%]. is there.

6) Combustion chamber spray deposit location:
In the characteristic at the right end of the lower stage of FIG. 10, the large mountain (see the thick solid line) is the distribution of the combustion chamber deposit XF, and the small mountain (see the thin solid line) is the distribution of the spray adhering to the combustion chamber wall. The area of this small peak is the combustion chamber wall deposit X3 [%], and the value obtained by subtracting this combustion chamber wall deposit X3 from the combustion chamber deposit XF is the cylinder surface wall deposit X4 [%].

  Thus, the intake system residuals XB and XC, the directly sprayed spray XD, the intake system adhering component XE, the combustion chamber wall adhering component XF, the injection vaporization component X0 ′, the floating components X0 ″, and X0 ″ ′ Is the same unit [%], but only XA represents the distribution itself, unlike these.

Hereinafter, the calculation method of the particle size distribution XA of the spray at the time of spraying, each branch XB, XC, XD, XF, X0 ′, X0 ″, and X0 ″ will be described in detail.
<2-1> Model identification of spray branching (vaporization)
1) XA: Particle size distribution of spray during spraying:
As the particle size distribution XA for the mass ratio of the spray at the time of injection, the spray measurement result of the injection valve 21 is used.

The particle size classification of the spray may be equal intervals (for example, every 10 μm) (see FIG. 11A), or may be classified every 2 ⁿ (see FIG. 11B). The greater the number of particle size categories, the better the accuracy. However, on the other hand, the memory capacity and calculation time increase, so it may be designed according to the CPU capacity.

  For simplicity, only one particle size classification may be used. This means that the average particle size of the total spray during injection is used. In this case, the evaporation rate and the retention rate of the spray are approximately determined from the particle diameter, and when the particle diameters are similar, the evaporation and retention characteristics can be approximated by experimental values. However, since the spraying method and the injection valve in which the spray particle size distribution changes greatly do not match, the spray particle size distribution may be used at this time.

2) X0 '; vaporization during injection:
As for the vaporization of the spray during injection, the mass of the spray is m, the surface area is A, the diameter is D, the vaporization amount of the spray is Δm, the flow velocity of the intake port 4 is V, and the temperature of the intake port 4 is T, as shown in FIG. If the pressure of the intake port 4 (this pressure is lower than the atmospheric pressure and becomes negative if the atmospheric pressure is used as a reference) is P, the vaporization rate X0 ′ and the vaporization amount Δm are expressed by the following equations. .

X0 ′ = Δm / m (16)
Δm = f (V, T, P) × A × t (17)
Here, f (V, T, P) in the equation (17) is a unit surface area and an evaporation amount per unit time (this value is hereinafter referred to as “vaporization characteristic”), and the vaporization characteristic f (V, T, P). Represents a function of the flow velocity V, temperature T, and pressure P. T in the equation (17) is a unit time.

In this case, since A = D ² × K1 # and m = D ³ × K2 # (K1 # and K2 # are constants), substituting these into the equations (16) and (17) and further deleting Δm The following equation is obtained.

X0 ′ = ΣXAk × f (V, T, P) × A × t × KA # / Dk (18)
Here, XAk is a mass ratio with respect to the particle size of the kth section, Dk is the particle size of the kth section, and Σ represents the summation over all the particle size sections (from 1 to the maximum number of sections). ing. KA # is an effective utilization factor (constant smaller than 1) at the surface area of the gas flow velocity V.

  The vaporization characteristic f (T, V, P) is obtained by searching a characteristic map having the contents shown in FIG. 13 from the temperature T and the flow velocity V. As shown in FIG. 13, the vaporization characteristic f (V, T, P) increases as the temperature T increases and the flow velocity V increases. In FIG. 13, the temperature on the horizontal axis is widely set from −40 ° C. to 300 ° C., but in reality, the vaporization and evaporation of the spray are performed in the region indicated as “temperature range”.

  The second term (Pa−P) / Pa × # KPT on the horizontal axis is the temperature correction due to the pressure P. This is because the volatility difference due to the pressure P, that is, when the pressure P is lower than the atmospheric pressure Pa as at low load, the amount of evaporation is larger than when the pressure P is higher than at low load as at high load. It is taken into consideration.

  By the way, among the parameters of the vaporization characteristic f (T, V, P), the flow velocity V includes a relative flow velocity component due to the spray penetration force and a flow velocity component due to the intake combustion chamber suction. The sum of the spray penetration and the intake airflow is obtained by the following equation instead of the above equation (18).

X0 ′ = ΣXAk × f (V1, T, P) × A × t1 × KA # / Dk
+ ΣXAk × f (V2, T, P) × A × t2 × KA # / Dk (19)
V1; spraying speed by spray penetration force,
t1: time required for spray penetration;
V2: the speed of the intake airflow,
t2: time during which the spray is exposed to the intake airflow,
Here, the spray velocity V1 due to the spray penetration force and the time t1 required for the spray penetration are constant values if the fuel pressure Pf acting on the injection valve 21 is determined. The values of V1 and t1 are determined when the specifications of the injection valve 21 are determined. In an engine in which the fuel pressure Pf is variably controlled, V1 and t1 vary depending on the fuel pressure Pf, and thus are set as a function of the fuel pressure Pf.

  Since the intake of air into the combustion chamber 5 is intermittent, the speed of the intake airflow (flow velocity of the intake port 4) V2 is proportional to the engine speed Ne, that is, V2 can be calculated by the following equation.

V2 = Ne × # KV (20)
Where #KV; flow velocity index,
The flow velocity index #KV in the equation (20) is a value determined by a value obtained by dividing the flow passage area (flow passage area of the intake port 4) by the cylinder volume. This index also includes unit alignment. Here, the flow path area and the cylinder volume can be obtained from the drawings.

  Since the exposure time t2 of the intake airflow representing the degree of exposure to the flow rate of the spray is affected by the injection timing I / T and the engine rotational speed Ne, the map having the contents shown in FIG. 14 from the injection timing I / T and the rotational speed Ne. Find by searching.

  Of the parameters of the vaporization characteristic f (T, V, P), the intake air temperature is used as the temperature T. However, when considering the residual gas (external EGR gas or internal EGR gas), the gas temperature mixed with the residual gas is used. This gas temperature is estimated from the intake air temperature and the water temperature. Simply, a simple average value or a weighted average value of the intake air temperature and the water temperature may be used as the estimated value of the gas temperature. The intake air temperature is detected by an intake air temperature sensor 44, and the water temperature is detected by a water temperature sensor 45. Ignore heat of vaporization and cover with conformity. Of the parameters of the vaporization characteristic f (T, V, P), the intake pressure is used as the pressure P. The intake pressure is detected by a pressure sensor 46 provided in the intake collector 2.

  Therefore, the intake temperature sensor 44 and the water temperature sensor 45 detect / estimate means for detecting or estimating the temperature of the part where the spray during spraying evaporates, the pressure sensor 46 detects the pressure at the part where the spray during spraying evaporates, and the crank The angle sensors (33, 34) are means for estimating the flow velocity of the portion where the spray during vaporization is vaporized.

3) XB: Spray remaining in the intake port:
When the injection vaporization amount X0 ′ is obtained in this way, the spray amount XB remaining in the intake port 4 while being sprayed is given by the following equation.

XB = XA−X0 ′ (21)
<2-2> Model identification of spray branching (direct injection)
1) XD: Spray amount directly injected into the combustion chamber 5:
If the spray from the injection valve 21 is an injection during the exhaust stroke, the intake valve 15 is fully closed, so that it only hits the intake valve 15 and the intake port 4 directly. When injecting in the intake stroke, a part thereof is injected directly into the combustion chamber 5 through the gap between the intake valve 15 and the valve seat without colliding with the intake valve 15 or the intake port as shown in FIG. This direct injection rate is set as KXD, and the spray amount XD directly injected into the combustion chamber 5 is calculated by the following equation.

XD = XB × KXD (22)
In addition to the injection timing, the direct injection rate KXD is also affected by the injection direction (the direction of the injection valve 21 and the direction of the intake valve 15). Therefore, the direct injection rate KXD is obtained by searching a map having the contents shown in FIG. 16 from the injection timing I / T and the sandwich angle β between the axis of the injection valve 21 and the axis of the intake valve 15. The sandwich angle β can be seen from the drawing. The characteristics shown in FIG. 16 are obtained by matching.

  Further, in an engine having an intake valve operating angle variable mechanism, the valve lift and profile of the intake valve also directly affect the injection rate KXD. Therefore, in the engine, the direct injection rate KXD is calculated by the following equation.

KXD = KXD0 × H / H0 (23)
Where H is the maximum intake valve lift,
H0: Standard maximum lift,
H0 in the equation (23) is the maximum lift of the intake valve when the intake valve operating angle variable mechanism is not operated. When the intake valve operating angle variable mechanism is operated, the maximum lift H of the intake valve is usually smaller than H0, and the direct injection rate is reduced accordingly. Therefore, the amount of reduction is corrected by the equation (23).

2) XC: Inhalation system residual spray:
When the spray amount XD directly injected is obtained in this way, the spray amount XC remaining in the intake system is given by the following equation.

XC = XB-XD (24)
<2-3> Model identification of spray branch (floating)
1) X0 ″; Floating matter in the intake system:
It is assumed that the spray is distributed throughout the intake port 4 and that each spray falls against the air due to the acceleration of gravity as shown in FIG. In such a natural fall model, the spray that falls and does not reach the port wall 4a floats, and the spray that reaches the port wall 4a is considered to adhere to the port wall 4a.

  However, in the natural fall, the spray drop speed is not related to the particle diameter D (∝mass) including the case where there is an air resistance proportional to the speed or the square of the speed. V is a function of the particle size D, and is assumed to increase as the particle size D increases as shown in FIG.

  The spray drop distance L is a value obtained by multiplying the drop velocity V by the spray floating time (or arrival limit time) t. When taking the maximum distance #L (port height #LP) to the wall surface in FIG. 18, all the sprays whose spray drop distance L is greater than or equal to this maximum distance #L adhere to the port wall 4a. As shown in FIG. 18, the characteristics of the floating component are downward-sloping, and a value obtained by summing up the particle size of the area where the floating component for each particle size is 0 or more becomes the floating component X0 ″ in the intake system. This can be obtained by the following equation.

X0 ″ = Σ (1-Lk / # LP) (25)
Here, Lk is a spray reach distance in the particle size classification k. This Lk is
Lk = Vk × tp (26)
(Vk is the spray falling speed in the particle size category k, tp is the time from the injection timing I / T as the floating time (or arrival limit time) to the start of the compression stroke), Substituting into the formula gives:

X0 ″ = Σ (1-Vk × tp / # LP) (27)
As a result, a table (see FIG. 18) of the spray drop velocity V for each of the small sections using the particle diameter D as a parameter is created, and the sum is obtained from the equation (27) until the particle diameter section k becomes 1 to D0. Then, the floating part X0 ″ in the intake system can be obtained. D0 is a particle size when the floating portion for each particle size becomes 0 in FIG. tp may be measured by a timer built in the engine controller 31. #LP is a constant value and is determined from the drawing.

2) X0 "': Floating matter in the combustion chamber:
The idea is the same as that of the floating part X0 ″ in the intake system. That is, it is assumed that sprays are distributed throughout the combustion chamber 5 and that each spray falls against the air by gravity acceleration as shown in FIG. In such a natural fall model, the spray that falls and does not reach the piston crown surface 6a floats, and the spray that reaches the piston crown surface 6a is considered to adhere to the combustion chamber (fuel chamber wall or cylinder surface wall 52).

  The spray drop speed V is a function of the particle diameter D, and is assumed to increase as the particle diameter D increases as shown in FIG.

  The spray drop distance L is a value obtained by multiplying the drop velocity V by the spray floating time (or arrival limit time) t. When taking the combustion chamber height #LC (for example, represented by the piston midpoint) that is the maximum distance #L to the wall surface in FIG. 18, the fuel spray whose spray drop distance L is equal to or greater than the combustion chamber height #LC is as follows. Since all of the particles adhere to the combustion chamber, the characteristics of the floating part for each particle size become a downward-sloping characteristic as shown in FIG. It becomes floating part X0 '' 'in. This can be obtained by the following equation.

X0 ″ ″ = Σ (1-Lk / # LC) (28)
Here, Lk is the spray reach distance in the particle size classification k, and this Lk is
Lk = Vk × tc (29)
(Vk is the spray drop speed in the particle size category k, tc is the end of the compression stroke (or combustion) from the injection timing I / T (or the start of the intake stroke) as the floating time (or the arrival limit time). Substituting this into the equation (28) gives the following equation:

X0 ″ ″ = Σ (1-Vk × tc / # LC) (30)
As a result, a table (see FIG. 18) of the spray drop speed V for each of the small sections using the particle diameter D as a parameter is created and summed up according to the equation (30) until the particle diameter section becomes D0 from 1. In this case, the floating part X0 "'in the combustion chamber can be obtained. D0 is a particle size when the floating portion for each particle size becomes 0 in FIG. The time may be measured by a timer built in the tc engine controller 31. #LC is a constant value and is determined from the drawing.

3) XE, XF: The amount adhering to the intake system and the combustion chamber:
Thus, when the floating part X0 ″ in the intake system and the floating part X0 ″ ″ in the combustion chamber are obtained, the intake system adhesion part XE and the combustion chamber adhesion part XF are given by the following equations.

XE = XC-X0 ″ (31)
XF = XD−X0 ′ ″ (32)
In an engine having an intake valve operating angle variable mechanism, secondary atomization of spray directly injected is promoted, and therefore, the sprayed XD directly injected and the floating X0 ′ ″ in the combustion chamber are corrected. Here, secondary atomization means that when the intake valve operating angle variable mechanism works, the maximum lift of the intake valve becomes small and the airflow flowing through the gap between the intake valve and the valve seat does not work for the intake valve operating angle variable mechanism. It is faster than that, and it means that atomization of the spray that is directly injected is promoted.

As a result of this secondary atomization, the distribution of the floating portion for each particle size and the amount of deposit in the combustion chamber for each particle size change from the solid line to the broken line as shown in the second characteristic from the right in the lower part of FIG. Transition. In order to obtain each distribution of the broken line characteristics, the distribution of the sprayed portion XD directly injected and the floating portion X0 '″ in the combustion chamber is corrected by shifting the lattice by 2 grids in the direction of decreasing the particle size, Using these new corrected distributions, the spray amount XD directly injected as described above and the floating portion X0 ″ ″ in the combustion chamber are obtained, and the obtained XD and X0 ″ ″ are calculated as (32 ) Used in the formula.
<2-4> Model identification of spray branch (attachment site)
1) X1, X2; intake valve wall adhesion, port wall adhesion:
The distribution of the intake system adhering portion XE is a lower solid line in FIG. 19, and the distribution of the intake valve wall adhering portion X1 is as shown by the lower broken line in FIG. 19, and the port wall is between the two distributions. This is the distribution of the deposit X2. Therefore, the intake system adhesion part XE is allocated to the intake valve wall adhesion part X1 and the port wall adhesion part X2 according to the intake valve direct hit rate #DVR as in the following equation.

X1 = XE × KX1 (33)
X2 = XE-X1 (34)
Where KX1: intake valve direct hit rate coefficient,
Here, the intake valve direct hit rate coefficient KX1 is obtained by searching a map containing FIG. 20 from the intake valve direct hit rate #DVR and the pressure P. As shown in FIG. 20, the intake valve direct hit rate coefficient KX1 increases as the intake valve direct hit rate #DVR increases. In addition, even when the intake valve direct hit rate #DVR is the same, the value of the intake valve direct hit rate coefficient KX1 is smaller at the time of low load where the pressure P is small. In FIG. 20, “no negative pressure” means a high load when the pressure P approaches atmospheric pressure, and “high negative pressure” means a low load when the pressure P becomes smaller than the atmospheric pressure. The intake valve direct hit rate #DVR is a ratio at which the spray from the injection valve 21 collides with the intake valve 15, and can be calculated from the drawings of the intake port 4 and the injection valve spray.

2) X3, X4: combustion chamber wall deposit, cylinder surface wall deposit:
The distribution of the spray adhering to the combustion chamber wall and the cylinder surface wall 52 is shown in FIG. The combustion chamber deposit XF is allocated to the combustion chamber wall deposit X3 and the cylinder surface wall deposit X4 as shown in the following equation at an allocation rate KX4.

X4 = XF × KX4 (35)
X3 = XF-X4 (36)
Here, a cylinder adhesion index is determined by the spray inflow layout, and an allocation rate KX4 is obtained by searching a table having the contents shown in FIG. 21 from the cylinder adhesion index. Here, the cylinder index represents the ratio of the fuel that sprays from the injection valve 21 passes through the gap between the intake valve 15 and the valve seat and enters the combustion chamber 5 and adheres to each wall toward the cylinder wall. For example, if the spray shape is a cone and the ratio of passing through the gap between the intake valve 15 and the valve seat is B and the ratio of B toward the cylinder wall is A, A / B may be used as the cylinder index. As shown in FIG. 21, the allocation rate KX4 is a value that increases as the cylinder adhesion index increases.

  The cylinder adhesion index can be set from the result of a flow simulation model, a part-by-part wall flow recovery experiment in a unit test, or the like.

  In this way, according to the branch model of the injection valve spray shown in FIG. 9, the branch ratios X0, X1, X2, X3, and X4 of the spray at the time of injection from the injection valve 21 can be calculated. Compared to the conventional method that uses a map or table directly from the operating conditions such as temperature, rotation speed, load signal, etc., the physical model is promoted, so it is possible to eliminate the adaptation by individual engine experiments. It is possible to reduce the number of conforming man-hours and the conforming period.

  Although not shown in the embodiment, since it has the particle size information of the spray, if it is calculated by extending it to the combustion process, it may lead to prediction of combustion efficiency and exhaust performance. have.

Next, the calculation of the wall flow branching ratios Y0 to Y2, Z0 to Z2, V0 to V1, and W0 to W2 that are the remaining branching ratios shown in FIG. 4 will be described.
<3> Model Identification of Wall Flow Evaporation and Removal Here, the basic concept for using a wall flow as a physical model is shown first.

1) Wall flow evaporation:
Consider a wall flow evaporation model as shown in FIG. That is, assuming that the evaporation surface area A is proportional to the wave height, and the wave height is proportional to the adhesion amount m, the following equation is established.

A = m × K # (37)
Where K #; constant,
The evaporation amount Δm is given by the following equation.

Δm = f (T, V, P) × A (38)
In equation (38), f (T, V, P) is the evaporation characteristic of the wall flow. Since the evaporation of the wall flow is the same as the evaporation of the spray, the vaporization characteristic shown in FIG. 13 is used as the evaporation characteristic of the wall flow. However, the equation (38) has no unit time t on the right side as compared with the equation (17). That is, Δm here is considered per unit time.

  When the equations (37) and (38) are used, the evaporation rate y of the wall flow is given by the following equation.

y = Δm / m = f (T, V, P) × K # (39)
As a result, the evaporation amount of the wall flow is proportional to the adhesion amount.

2) Carrying away wall flow (spray re-scattering, wall flow movement):
Consider a model of wall flow re-scattering (scattering) and wall flow movement as shown in FIG. That is, assuming that the re-scattering amount Δm ′ of the wall flow is also proportional to the wave height and the wave height is proportional to the adhesion amount m, the wall flow scattering rate y1 and 2 are given by the following equations.

y1,2 = Δm ′ / m = f (T, V, viscosity, surface tension) × K # (40)
F (T, V, viscosity, surface tension) in the equation (40) is a rescattering rate basic value (scattering rate basic value), and its characteristics are shown in FIG. When gasoline as the fuel to be used is determined, the viscosity and the surface tension are determined, and the characteristics with respect to the temperature T and the flow velocity V are obtained as shown in FIG. The re-scattering rate basic value is a value that increases as the temperature T increases and the flow velocity V increases.

  From this, it is assumed that the amount of re-scattering of the wall flow is also proportional to the amount of adhesion.

  Similarly, in FIG. 23, assuming that the wall flow moves while being pushed by the flow velocity V, and the moving speed of the wall flow is not affected by the wall flow thickness H, the wall flow movement amount Δm ″, the wall flow thickness H is given by:

Δm ″ = H × Vw (41)
H = m × K # (42)
Where Vw: wall flow velocity,
The moving velocity Vw of the wall flow of the equation (41) is
Vw = f (V, T, viscosity) (43)
It is. Here, f (V, T, viscosity) in the equation (43) is a basic value of the mobility, and its characteristics are shown in FIG. When the gasoline as the fuel to be used is determined, the viscosity is determined, and by adapting to the fuel to be used, characteristics with respect to the temperature T and the flow velocity V can be obtained as shown in FIG. The movement rate basic value is a value that increases as the temperature T increases and the flow velocity V increases.

  When the equations (41) to (43) are used, the wall flow movement rates y1 and 2 'are given by the following equations.

y1, 2 ′ = Δm / m = f (V, T, viscosity) × K # (44)
From this, it is assumed that the amount of wall flow movement is also proportional to the amount of adhesion.

In this way, the wall flow model described below is constructed assuming that the evaporation and removal of the wall flow are all proportional to the amount of adhesion.
<4-1> Application to each part model of evaporation and removal 1) Application to intake valve wall flow:
FIG. 26 is a diagram in which the wall flow model of FIGS. 22 and 23 is applied to the wall flow formed in the intake valve 15. The evaporative combustion from the intake valve wall flow, the branch from the intake valve wall flow to the combustion chamber wall, and the branch from the intake valve wall flow to the cylinder surface wall 52 are calculated as follows.

Evaporative combustion: Y0 = Δm / m
= F (FIG. 13) × # KWVV (45)
Combustion chamber wall branch; Y1 = (Δm ′ + Δm ″) / m
= F (FIG. 24) × # KVC + f (FIG. 25) × # KVT
... (46)
Cylinder wall branch; Y2 = (Δm ′ + Δm ″) / m
= F (FIG. 24) × (1- # KVC)
+ F (FIG. 25) (1− # KVT) (47)
Here, #KWVV is an evaporation coefficient of the intake valve wall flow, #KVC is a re-scattering coefficient of the intake valve wall flow, and #KVT is a movement coefficient of the intake valve wall flow.

2) Application to intake port wall flow:
FIG. 27 is a diagram in which the wall flow model of FIGS. 22 and 23 is applied to the wall flow formed in the intake port. The evaporative combustion from the intake port wall flow, the branch from the intake port wall flow to the combustion chamber wall, and the branch from the intake port wall flow to the cylinder surface wall 52 are calculated as follows.

Evaporative combustion: Z0 = Δm / m
= F (FIG. 13) × # KWVP (48)
Combustion chamber wall branch: Z1 = (Δm ′ + Δm ″) / m
= F (FIG. 24) × # KHC + f (FIG. 25) × # KHT
... (49)
Cylinder wall branching; Z2 = (Δm ′ + Δm ″) / m
= F (FIG. 24) × (1− # KHC)
+ F (FIG. 25) (1− # KHT) (50)
Here, #KWVP is an evaporation coefficient of the intake port wall flow, #KHC is a re-scattering coefficient of the intake port wall flow, and #KHT is a movement coefficient of the intake port wall flow.

  In the above equations (45) to (50), f (FIG. 13) is the vaporization characteristic f (V, T, P) shown in FIG. 13, and f (FIG. 24) is the rescattering rate basic value shown in FIG. f (T, V, viscosity, surface tension) f (FIG. 25) is the basic value f (V, T, viscosity) of the mobility shown in FIG.

  In this case, the temperature T, the flow velocity V, and the pressure P used to obtain f (FIG. 13), f (FIG. 24), and f (FIG. 25) are estimated or calculated as follows.

  First, the temperature is as follows. The temperature when applied to the intake valve wall flow is the temperature of the intake valve wall 15a, and the temperature when applied to the intake port wall flow is the temperature of the port wall 4a. As the temperature of the intake valve wall 15a, a temperature calculated by a known method (see Japanese Patent Laid-Open No. 3-134237) from the water temperature and operating conditions may be used. As the temperature of the port wall 4a, a water temperature or a temperature lower than the water temperature by a predetermined value (for example, about 15 ° C.) may be used.

  The flow velocity V and the pressure P are the same when applied to the intake valve wall flow and when applied to the intake port wall flow. The flow velocity V may be calculated using the above equation (20) described in the vaporization characteristics. When secondary atomization is considered, the channel area (the channel area of the intake port 4) is corrected to a smaller side. The pressure P is detected by the pressure sensor 46.

  Accordingly, the water temperature sensor 45 detects or estimates the temperature of the evaporation or removal part of the wall flow fuel, the pressure sensor 46 detects the pressure of the evaporation or removal part of the wall flow fuel, and the crank angle. Sensors (33, 34) are means for estimating the flow velocity of the vaporized or carried away wall flow fuel.

  The above evaporation coefficients (#KWVV and #KWVP), re-scattering coefficients (#KVC and #KHC), and movement coefficients (#KVT and #KHT) are the wetting areas of wall flow (intake valve wall flow and intake port wall flow) A fitting term that is a function of the length that the wall flow travels.

In this way, the evaporation and removal from the intake valve wall flow (Y0, Y1, Y2) and the evaporation and removal from the intake port wall flow (Z0, Z1, Z2) are calculated separately. The formula is the same and only the input parameters (temperature, flow rate, pressure) are different, which also contributes to shortening the time required for adaptation.
<4-2> Application to each model of evaporation and removal 1) Application to combustion chamber wall flow:
FIG. 28 is a diagram in which the wall flow model of FIG. 22 is applied to the wall flow formed in the combustion chamber (excluding the cylinder face wall). The vaporized combustion amount from the combustion chamber wall flow and the vaporized unburned exhaust amount from the combustion chamber wall flow are calculated as follows.

Vaporized combustion: V0 = f (FIG. 13) × # KCV (51)
Vaporization unburned discharge; V1 = f (FIG. 13) × # KCL (52)
Here, #KCV is the evaporation coefficient of the combustion chamber wall flow, and #KCV is the evaporation coefficient of the combustion chamber wall flow.

2) Application to cylinder wall flow:
FIG. 29 is a diagram in which the wall flow model of FIGS. 22 and 23 is applied to a wall flow formed on a cylinder face wall. The vaporized combustion from the cylinder face wall flow, the vaporized unburned discharge from the cylinder face wall flow, and the oil mixture from the cylinder face wall flow are calculated as follows.

Evaporative combustion: W0 = f (FIG. 13) × # KBV (53)
Evaporation unburned discharge; W1 = f (FIG. 13) × # KBL (54)
Oil content: W2 = f (FIG. 30) × # KBO (55)
Here, #KBV is the evaporation coefficient of the cylinder face wall flow, #KBL is the evaporation coefficient of the cylinder face wall flow, and #KBO is the oil mixing coefficient of the cylinder face wall flow.

  In the above equations (51) to (55), f (FIG. 13) is the vaporization characteristic f (V, T, P) shown in FIG. 13, and f (FIG. 30) is the oil mixing rate basic value shown in FIG. It is f (Ne, Tp). As shown in FIG. 30, the basic value of the oil mixture rate is a value that decreases as the engine speed increases when the basic injection amount Tp is the same, and increases as the basic injection amount Tp increases when the engine speed is the same.

  Here, the temperature T, the flow velocity V, and the pressure P in the section of the vaporized combustion used to obtain f (FIG. 13) of the equations (51) and (53), and f (5) of the equations (52) and (54). The temperature T, the flow velocity V, and the pressure P in the section of the vaporized unburned exhaust used for obtaining FIG. 13) are estimated or calculated as follows.

  (A) Temperature: During one combustion cycle, the temperature changes as shown in FIG. 31. Therefore, the temperature is estimated or calculated separately for the vaporized combustion section and the vaporized unburned exhaust section shown in FIG. In each section, a weighted combined temperature of the gas temperature of the section and the estimated value of the wall temperature (the temperature of the combustion chamber wall or the temperature of the cylinder face wall 52) is used.

  In brief, when the weighted composite temperature is averaged in each section, the average temperature changes depending on the operating conditions (load and rotational speed), so a map of the average temperature using the load and rotational speed as parameters is created by experimentation. The average temperature in each section is calculated by searching the map.

  (B) Pressure: Since the pressure changes as shown in FIG. 31 during one combustion cycle, it is divided into the vaporized combustion section and the unburned exhaust section shown in FIG. Use the average pressure averaged. Since this average pressure also changes depending on the operating conditions (load and rotation speed), a map of average pressure with the load and rotation speed as parameters is experimentally created and searched for each map by searching the map. Calculate the average pressure.

  (C) Flow velocity: Since the flow velocity changes as shown in FIG. 31 during one combustion cycle, it is assumed that the velocity is proportional to and attenuated with the intake air flow V2 of the above equation (20), and the average flow velocity V averaged in each section is Calculate as follows.

Vaporized combustion section: Average flow velocity V = V2 × # KIV (56)
Vapor unburned discharge interval; average flow velocity Vc = V2 × # KIL (57)
Here, #KIV and #KIL are constants.

  As described above, the vaporized combustion amount from the combustion chamber wall flow, the vaporized unburned exhaust amount (V0, V1), the vaporized combustion amount from the cylinder face wall flow, and the vaporized unburned exhaust amount (W0, W1) are the intake valve. As with the evaporation and removal from the wall flow (Y0, Y1, Y2) and the evaporation and removal from the intake port wall flow (Z0, Z1, Z2), they are calculated separately, but the equations are the same. There are only different parameters (temperature, flow velocity, pressure) to be input, which also contributes to shortening the time required for adaptation.

  In this way, according to the present embodiment, each branch of spray during spraying (XB, XC, XD, XF, X0 ′, X0 ″, X0 ″ ′) and each branch of wall flow (Y0, Y1) , Y2, Z0, Z1, Z2, V0, V1, W0, W1, W2), all use engine design drawings and specifications of parts such as the injection valve 21, and therefore, once. Although it is necessary to experiment with the map and table characteristics, the map and table characteristics need hardly be changed even if the engine model changes.

  In addition, since the required air-fuel ratio is derived from the quality of combustion (difference in unburned fuel) due to the diffusion combustion of the spray (see the above formulas (12a) and (12b)), various increases in the air-fuel ratio (enrichment) ) Control can be integrated, and as explained in the formulas (13) and (14), the various increase logics (water temperature increase, post-start-up increase, start-up increase, fully-open increase, etc.) that were necessary in the past are unnecessary. Since the control is simplified and the adaptation can be abolished or simplified, this also contributes to the reduction of the man-hours and the period of the adaptation. Further, by combining the spray particle size up to combustion, it is possible to connect to the estimation technology for the generation of HC and smoke due to unauthorized combustion.

  Here, the operation of the present embodiment will be described.

According to the present embodiment (the invention described in claim 1 ), the vaporization during injection X0 ′ using the vaporization characteristics f (V, T, P) (basic characteristics related to vaporization during spray during injection) shown in FIG. (Evaporation amount vaporization rate of injection spray) is calculated, and the fuel injection amount from the fuel injection valve 25 is calculated using the calculated injection vaporization amount X0 ′. Even if the vaporization amount X0 ′ during injection differs due to the difference in particle size, the vaporization fraction X0 ′ during injection can be calculated using the same vaporization characteristics f (V, T, P) shown in FIG. Conformance experiments are not required, the number of man-hours for conformance can be greatly reduced, and the time required for conformance can be shortened.

According to the present embodiment (the invention described in claim 2 ) , in addition to the flow velocity V and the temperature T of the portion where the spray during vaporization is vaporized, the pressure at the portion where the spray during vaporization is vaporized is used in combination. The calculation accuracy of the vaporization amount X0 ′ can be improved.

  In the embodiment, the case has been described in which the vaporization rate (X0 ′) of the spray during spraying is calculated using the basic characteristics related to the vaporization during spraying (characteristics shown in FIG. 13). The vaporization amount of the spray during injection may be calculated using the characteristics.

  In the embodiment, the L-Jetronic gasoline injection engine has been described, but the present invention can also be applied to a D-Jetronic gasoline injection engine.

The functions of the quantity / rate calculating means and the fuel injection amount calculating means according to claim 1 are performed by the engine controller 31.

1 is a system diagram of an automobile engine showing an embodiment of the present invention. The conceptual diagram which shows the behavior of the air-fuel | gaseous mixture in an intake port and a combustion chamber. The conceptual diagram which shows the behavior of the air-fuel | gaseous mixture in an intake port and a combustion chamber. The data flow figure of the air-fuel | gaseous mixture model of an intake port and a combustion chamber. The data flow figure of a fuel injection amount calculation model. The characteristic figure of the required frequency with respect to the time after starting. The characteristic figure of the request | requirement frequency with respect to accelerator opening. The characteristic figure of the required frequency with respect to catalyst temperature. The data flow figure of the branch model of injection valve spray. The model figure which shows the process of the whole spray branch. The characteristic view of the particle size distribution about the mass ratio of the spray at the time of injection. The model figure for demonstrating the vaporization rate of spraying. The characteristic view of the vaporization characteristic f (V, T, P). The characteristic figure of the exposure time of intake airflow. The model figure for demonstrating the direct injection to the combustion chamber of spray, and the slipping out of a spot. The characteristic figure of the direct injection rate with respect to injection timing and (beta). The model figure for demonstrating the floating in the intake system of spray, and the floating in a combustion chamber. The characteristic figure of the spray fall speed and the floating ratio for every particle size. The characteristic view which shows spraying particle size distribution. The characteristic diagram of the intake valve direct hit rate coefficient with respect to the intake valve direct hit rate and the ratio X1 / X2. The characteristic figure of the allocation rate with respect to ratio X3 / X4. The wall flow model figure for demonstrating the evaporation from a wall flow. The wall flow model diagram for explaining re-scattering from the wall flow and the movement of the wall flow. The characteristic figure of a re-scattering rate basic value. The characteristic figure of a movement rate basic value. The wall flow model figure for demonstrating the evaporation from the intake valve wall flow, and taking away. A wall flow model for explaining evaporation and removal from a port wall flow. The wall flow model figure for demonstrating the evaporation from a combustion chamber wall flow. The model figure for demonstrating the evaporation from a cylinder surface wall flow, and taking away. Fig. 3 is a characteristic diagram of the basic value of oil mixing rate. The characteristic view which shows the change of the pressure in one combustion cycle, temperature, and flow velocity.

Explanation of symbols

4 Intake Port 5 Combustion Chamber 15 Intake Valve 21 Fuel Injection Valve 31 Engine Controller 33 Crank Angle Sensor 34 Crank Angle Sensor 42 Accelerator Sensor 44 Intake Temperature Sensor 45 Water Temperature Sensor 46 Pressure Sensor

Claims (3)

An intake valve for opening and closing the intake port at the combustion chamber inlet;
A fuel injection valve for injecting fuel into the intake port;
And basic characteristics related to vaporization of the injected during spray injected from the fuel injection valve, and detection and estimation means for detecting or estimating the temperature of the site of vaporization of the injection time of spraying, the site of vaporization of the injection timing spray The flow rate is divided into the spray speed by the penetration force of the spray at the time of injection and the speed of the intake airflow. Of these, the spray speed is set according to the specifications of the fuel injection valve, and the speed of the intake airflow is proportional to the engine speed. and a speed setting and estimating means for estimating Te, the injection time of spraying with the detected or estimated temperature, the set spray velocity and the estimated before Kimoto present characteristics from the velocity of the intake air flow was An amount / rate calculating means for calculating the vaporization amount or vaporization rate of
Fuel injection amount control apparatus for an engine, characterized in that the calculated vaporized amount or by using the evaporation rate and a fuel injection amount calculating means for calculating a fuel injection amount from the fuel injection valve. The apparatus according to claim 1 , further comprising a detection / estimation unit that detects or estimates a pressure at a part where the spray during spraying is vaporized, and the pressure is also used when calculating a vaporization amount or a vaporization rate of the spray during spraying. The fuel injection amount control device for an engine according to claim 1 . 3. The map according to claim 2 , wherein the basic characteristic is a map having two parameters, the set spray speed or the estimated intake airflow speed and the temperature corrected by the pressure. 2. A fuel injection amount control device for an engine according to 1.

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