DE102012103139B4 - Fuel injection control device for an internal combustion engine - Google Patents

Abstract

A fuel injection control apparatus for a fuel injection system of an internal combustion engine, comprising an accumulator (18) adapted to accumulate fuel in a high pressure state, a fuel pump (14) for supplying fuel from a fuel tank (10) to the accumulator (18). is formed, and a Kraftstoffinjektionsventil (24,24a), which is adapted to receive the fuel accumulated in the accumulator (18) and a fuel inlet (40,40a) and a nozzle needle (42,82), wherein the fuel inlet (40 , 40a) receives the fuel supplied from the accumulator (18) and the nozzle needle (42, 82) is designed to open and close a fuel injection opening (30, 30a) of the fuel injection valve (24, 24a), characterized in that Residence time calculating means (S12) adapted to calculate a dwell period correspondence value (t) s, corresponding to a residence time of the fuel in the fuel injection valve (24, 24a) from a time of entry into the fuel injection valve (24, 24a) through the fuel inlet (40, 40a), based on: ◦ a volume V of the high pressure fuel passage (39) from the fuel inlet (40) to an estimation position α; ◦ of a fuel injection amount (Q) to be injected from the fuel injection valve (24,24a) per combustion cycle of the engine◦ of a (Q) amount of dynamic loss including Fuel output from the fuel injection valve (24) through a low-pressure fuel passage (54) to a fuel tank (10) due to the movement of the nozzle needle (42) at the time of fuel injection◦ of a time period corresponding to a combustion cycle; a fuel temperature estimation means (S16) is provided, which is adapted to a fuel temp in the fuel injection valve (24, 24a), based on a difference between the temperature (T) of the fuel injection valve (24, 24a) and a fuel temperature (T) of the fuel entering the fuel inlet (40, 40a) ; and◦ the dwell period correspondence value (t) calculated by the dwell period calculating means (S12), wherein correcting means (S18, S20) adapted to supply an injection amount (Q) from the fuel injection valve (24, 24a) to correct the fuel to be injected based on the fuel temperature (T) estimated by the fuel temperature estimator (S16); and - wherein a control device (64e) is provided, which is adapted to control a power supply of the fuel injection valve (24,24a) based on a corrected fuel injection amount (Q), which is corrected by the correcting means (S18, S20).

Description

TECHNICAL AREA

The present disclosure relates to a fuel injection control device and a method for controlling fuel injection for an internal combustion engine.

BACKGROUND

It is known to provide a fuel injection control device in an internal combustion engine fuel injection system that includes an accumulator, a fuel pump, and an electronically controlled fuel injection valve. The accumulator can accumulate the fuel in a high pressure state. The fuel pump pumps the fuel from the fuel tank to the battery. The fuel injection valve receives the fuel from the accumulator. Such a fuel injection control device is shown in FIG JP2005-180352A shown. The fuel injection control device of the JP2005-180352A limits deterioration in a fuel injection quantity adjustment accuracy in the fuel injection valve caused by a change in a cross-sectional area of a fuel passage in the fuel injection valve that directs the fuel supplied from the accumulator to fuel injection ports, the change induced by a temperature change of the fuel injection valve is. In particular, the fuel injection control device estimates the JP2005-180352A the temperature of the fuel fed to the fuel injection valve based on a flow amount of the fuel fed to the fuel injection valve through a fuel pipe that extends from the fuel tank to the fuel injection valve. Then, the fuel injection control device estimates the temperature of the fuel injection valve based on the estimated temperature of the fuel. Thereafter, the fuel injection control device corrects the fuel injection amount at the fuel injection valve based on the estimated temperature of the fuel injection valve. In this way, deterioration in the adjustment accuracy of the fuel injection amount caused by the change in the temperature of the fuel injection valve is limited.

When the fuel that is supplied from the accumulator to the fuel inlet of the fuel injection valve flows through the fuel injection valve, heat exchange takes place between the fuel (hereinafter referred to as passing fuel) that passes through the fuel injection valve and the fuel injection valve. As a result, the temperature of the fuel entering the fuel inlet of the fuel injection valve may differ from the temperature of the fuel passing through. In such a case, as a result of a change in the viscosity of the fuel passing through, an influence of the passing fuel on a nozzle needle of the fuel injection valve can change, which opens or closes a fuel injection opening. In such a case, the behavior of the nozzle needle, i.e. change the movement characteristic of the nozzle needle, possibly at the time of injecting the fuel from the fuel injection valve, so that the fuel injection quantity from the fuel injection valve may deviate from an originally intended preset quantity.

Another fuel injection control device is off JP 2006-132517A known. JP 2006-132517A discloses a fuel supply apparatus for an internal combustion engine having only a cylinder injector for injecting fuel into a cylinder or an internal combustion engine having the cylinder injector and an intake manifold or an intake passage.

SUMMARY

The present disclosure is directed to the above disadvantages. Accordingly, it is an object of the present disclosure to provide a fuel injection control apparatus and a fuel injection control method of an internal combustion engine that appropriately restrict (limit) a deviation in the adjustment accuracy of a fuel injection amount in a fuel injection valve.

According to the present disclosure, there are provided a fuel injection control device and a fuel injection control method for a fuel injection system of an internal combustion engine, which includes an accumulator adapted to accumulate fuel in a high pressure state, a fuel pump for supplying fuel from a fuel tank adapted to the accumulator, and includes a fuel injection valve adapted to receive the fuel accumulated in the accumulator and including a fuel inlet and a nozzle needle. The fuel inlet receives the fuel supplied from the accumulator, and the nozzle needle is adapted to open and close a fuel injection port in the fuel injection valve. The fuel injection control device includes a temperature estimator, a corrector, and a controller. The fuel temperature estimator estimates a A fuel temperature of the fuel in the fuel injection valve such that when a residence time correspondence value corresponding to a residence time of the fuel in the fuel injection valve since a time of entering the fuel injection valve through the fuel inlet increases, the fuel temperature estimated by the fuel temperature estimating means is a temperature of the fuel injection valve is approximated in a case where there is a difference between the temperature of the fuel injection valve and the fuel temperature of the fuel entering the fuel inlet. The correcting means corrects a fuel injection amount to be injected from the fuel injection valve based on the fuel temperature estimated by the fuel temperature estimating means. The controller controls a power supply of the fuel injection valve based on a corrected fuel injection amount corrected by the correcting means.

list of figures

• 1: ist eine Schemadarstellung, die ein System gemäß einem Ausführungsbeispiel der vorliegenden Offenbarung zeigt;
• 2: ist eine Darstellung, die eine Beziehung zwischen einer Kraftstofftemperatur und einer Kraftstoffeinspritzmenge gemäß dem Ausführungsbeispiel zeigt;
• 3: ist eine teilweise vergrößerte Ansicht, die ein Kraftstoffinjektionsventil gemäß dem Ausführungsbeispiel zeigt;
• 4: ist eine Darstellung, die eine Beziehung zwischen der Kraftstofftemperatur und einer Kraftstoffviskosität gemäß dem Ausführungsbeispiel zeigt;
• 5A: ist eine Draufsicht, die einen ringförmigen Spalt des Kraftstoffinjektionsventils des Ausführungsbeispiels zeigt;
• 5B: ist eine Querschnittansicht gemäß Linie VB-VB in 5A;
• 6A: ist eine Darstellung, die eine Veränderung in einem Treibersignal zeigt, das an einen elektrischen Aktuator des Kraftstoffinjektionsventils des vorliegenden Ausführungsbeispiels über der Zeit zeigt;
• 6B: ist eine Darstellung, die eine Veränderung in einer Kraftstoffeinspritzrate bei dem Kraftstoffinjektionsventil des Ausführungsbeispiels über der Zeit zeigt;
• 7: ist ein Ablaufdiagramm, das einen Korrekturvorgang der Kraftstoffinjektionsmenge bei dem Kraftstoffinjektionsventil gemäß dem Ausführungsbeispiel zeigt;
• 8: ist eine Darstellung, die ein Schätzverfahren für eine Kraftstofftemperatur in dem Kraftstoffinjektionsventil gemäß dem Ausführungsbeispiel zeigt;
• 9: ist eine Darstellung, die ein Korrekturverfahren für eine Kraftstoffinjektionsmenge bei dem Kraftstoffinjektionsventil gemäß dem Ausführungsbeispiel zeigt;
• 10: ist eine schematische Querschnittansicht, die eine Abwandlung des Ausführungsbeispiels zeigt und
• 11: ist eine Darstellung, die eine Beziehung zwischen einer Kraftstofftemperatur und einer Kraftstoffinjektionsmenge bei der Abwandlung gemäß 10 zeigt.

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

• 1 12 is a schematic diagram showing a system according to an embodiment of the present disclosure;
• 2 FIG. 15 is a diagram showing a relationship between a fuel temperature and a fuel injection amount according to the embodiment; FIG.
• 3 1 is a partially enlarged view showing a fuel injection valve according to the embodiment;
• 4 FIG. 15 is a graph showing a relationship between the fuel temperature and a fuel viscosity according to the embodiment; FIG.
• 5A FIG. 10 is a plan view showing an annular gap of the fuel injection valve of the embodiment; FIG.
• 5B : is a cross-sectional view along the line VB-VB in 5A ;
• 6A FIG. 10 is a diagram showing a change in a drive signal indicative of an electric actuator of the fuel injection valve of the present embodiment over time; FIG.
• 6B FIG. 12 is a graph showing a change in fuel injection rate in the fuel injection valve of the embodiment over time; FIG.
• 7 FIG. 10 is a flowchart showing a correction process of the fuel injection amount in the fuel injection valve according to the embodiment; FIG.
• 8th FIG. 1 is a diagram showing a fuel temperature estimating method in the fuel injection valve according to the embodiment; FIG.
• 9 FIG. 1 is a diagram showing a correction method for a fuel injection amount in the fuel injection valve according to the embodiment; FIG.
• 10 is a schematic cross-sectional view showing a modification of the embodiment and
• 11 FIG. 15 is a graph showing a relationship between a fuel temperature and a fuel injection amount in the modification of FIG 10 shows.

DETAILED DESCRIPTION

With reference to the accompanying drawings, an embodiment of the present disclosure will be described. In the present embodiment, a fuel injection control device of the present disclosure is applied to a battery-type fuel injection system of a vehicle (for example, an automobile) that includes a four-cycle multi-cylinder diesel engine (in this case, a four-cylinder diesel engine) an intake stroke, a compression stroke, an expansion stroke and an exhaust stroke are performed in a combustion cycle (720 ° crankshaft angle (CA)).

1 FIG. 12 is a diagram schematically showing the system of the present embodiment.

As in 1 fuel (light oil) stored in a fuel tank ( 10 ) is received from a motor driven fuel pump ( 14 ) sucked and fed by rotation of a crankshaft ( 12 ) is driven. In particular, the fuel pump ( 14 ) a Trochoid feed pump and a Hochdruckplungerpumpe. The trochoid pump draws fuel out of the fuel tank ( 10 ) by a low pressure line ( 16 ). The high-pressure plunger pump pressurizes the drawn-in fuel and feeds (pumps) the pressurized fuel to a common rail (FIG. 18 ).

The fuel pump ( 14 ) also includes an inlet metering valve and a fuel temperature sensor ( 20 ). The inlet metering valve is an electronically controlled valve element, the one Withdrawal quantity of the fuel pump ( 14 ) by adjusting an amount of fuel drawn into the high pressure pump. The fuel temperature sensor ( 20 ) detects a temperature of a fuel in the fuel pump ( 14 ) (a pump inlet fuel temperature, which is the temperature of a fuel drawn by the feed pump).

The fuel pump ( 14 ) fuel is added to the Common Rail ( 18 ) guided. The common rail ( 18 ) is an accumulator which accumulates the high-pressure fuel which is discharged from the fuel pump ( 14 ) and the accumulated fuel through a high pressure line ( 22 ) to fuel injection valves ( 24 ), which are provided on the cylinders and electronically controlled. A fuel pressure sensor ( 25 ) is at the common rail ( 18 ) is provided to a pressure (rail pressure) of a fuel in an inside of the common rail ( 18 ) capture.

The fuel injection valve ( 24 ) includes a body ( 26 ) (a part including a nozzle body and a holder body) and a pressure chamber forming member ( 28 ). A plurality of fuel injection ports ( 30 ) is in the body ( 26 ) and is in a combustion chamber ( 32 ) of the engine.

In particular, the body ( 26 ) the fuel injection ports ( 30 ), a needle seat area ( 34 ), a needle receiving chamber ( 36 ), a fuel passage ( 38 ) and a fuel inlet ( 40 ) that, in this order, from a distal end side to a proximal side of the fuel injection valve ( 24 ) are formed. The needle seat area ( 34 ) is designed in a ring shape. The needle receiving chamber ( 36 ) is designed in a cylindrical shape. The fuel passage ( 38 ) extends in the direction of a central axis (i.e. in an axial direction) of the fuel injection valve ( 24 ) and is with a needle receiving chamber ( 36 ) connected. The fuel inlet ( 40 ) takes the high pressure fuel from the common rail and is with the fuel passage ( 38 ) connected.

The needle receiving chamber ( 36 ) takes the nozzle needle ( 42 ) in the axial direction of the fuel injection valve ( 24 ) can be moved back and forth. The nozzle needle ( 42 ) is a basically cylindrical valve element (needle valve), which is located in an axial direction of the fuel injection valve ( 24 ) extends. The nozzle needle ( 42 ) includes a distal end area ( 42a ), a leadership area (enlarged area) ( 42b ) and a back pressure area ( 42c ), which in this order from a distal end side (one side at the injection openings ( 30 )) to a proximal side of the nozzle needle ( 42 ) are arranged. The distal end area ( 42a) is adapted to the fuel injection openings ( 30 ) to open or close. An annular fuel passage that is in the axial direction of the fuel injection valve ( 24 ) extends between an outer peripheral surface of the nozzle needle ( 42 ) and an inner wall of an area of the body ( 26 ) formed which the needle receiving chamber ( 36 ) forms.

When the distal end region ( 42a ) of the nozzle needle ( 42 ) against the needle seat area ( 34 ), the needle receiving chamber ( 36 ) and the combustion chamber ( 32 ) separated from each other. When the distal end region ( 42a ) of the nozzle needle ( 32 ) from the needle seat area ( 343 ) is lifted, the needle receiving chamber ( 36 ) with the combustion chamber ( 32 ) connected.

The management area ( 42b ) is formed as a basically cylindrical body extending in the axial direction of the fuel injection valve (FIG. 24 ) and has a larger outer diameter than the distal end portion (FIG. 42a ), to the management area ( 42b ) adjoins. In particular, the management area ( 42b ) at a corresponding point of the nozzle needle ( 42 ) corresponding to the annular fuel passage discussed above. The management area ( 42b ) slidably contacts the inner wall of the area of the body ( 26 ), the needle receiving chamber ( 36 ) to provide a movement stabilizing function for stabilizing the axial movement of the nozzle needle ( 42 ) and thereby a storage of the distal end region ( 42a ) at a deviating point which is separated from the needle seat area (FIG. 34 ) deviates.

In the following discussion of the present embodiment, the fuel passage ( 38 ) and the annular fuel passage discussed above, collectively as a high pressure fuel passage (FIG. 39 ) designated. The fuel passing through the fuel inlet ( 40 ) is fed through the high pressure passage ( 39 ) to the fuel injection ports ( 30 ) guided.

The nozzle needle ( 42 ) is replaced by a needle spring ( 44 ) in the direction of the fuel injection openings ( 30 ) axially driven.

The back pressure area ( 42c ) is on one axial side (back) of the nozzle needle ( 42 ) provided opposite to the axial side of the nozzle needle ( 42 ), which corresponds to the needle seat area ( 34 ) is opposite. Furthermore, the back pressure area ( 42c) a pressure control chamber ( 46 ) opposite.

The pressure control chamber ( 46 ) is through the back pressure area ( 42c ) (the proximal end, i.e. the rear end of the nozzle needle ( 42 )) and the pressure chamber formation element ( 28 ) and is defined by a mouth ( 48 ) with a control valve receiving chamber ( 50 ) connected.

The control valve receiving chamber ( 50 ) is by the operation of a control valve (control valve element) ( 52 ) located in the control valve receiving chamber ( 50 ), either with the high-pressure fuel passage ( 39 ) or a low-pressure fuel passage ( 54 ) connected. In particular, a valve spring ( 56 ) on the control valve ( 52 ) in a closing direction for closing the connection between the control valve accommodating chamber (FIG. 50 ) and the low-pressure fuel passage ( 54 ) a driving force.

Furthermore, the control valve ( 52 ) by an electric actuator ( 62 ) via a piston ( 58 ) and an offset gain region (offset gain chamber) ( 60 ) displaceable.

The offset gain range ( 60 ) has a function for increasing an offset amount of the piston (FIG. 58 ) at a predetermined fluid (that is, at from a fuel injection valve ( 24 ) fuel to be injected).

The electric actuator ( 62 ) is a part extending in the axial direction of the fuel injection valve (FIG. 24 ), that is, is elongated in this direction. The electric actuator ( 62 ) is in the body ( 26 ) arranged such that the electric actuator ( 62 ) and the fuel passage ( 38 ) are generally parallel to each other and in a direction perpendicular to the axial direction of the fuel injection valve (FIG. 24 ) (that is, perpendicular to the central axis of the fuel injection valve ( 24 )) are arranged one behind the other. With this arrangement, the pressure control chamber ( 46 ) in the axial direction of the fuel injection valve (FIG. 24 ) on the side of the fuel injection openings ( 30 ) of the electric actuator ( 62 ) arranged.

Here in the present exemplary embodiment, the electrical actuator ( 62 ) a plurality of piezoelectronic elements and a plurality of electrode plates which are alternately stacked one above the other to form a piezoelectronic stack. The piezoelectric element is a capacitive load that can be expanded or contracted by the piezoelectric effect, and the charging and discharging of the piezoelectric element causes the piezoelectric element to expand and contract. The piezoelectric elements and the electrode plates are alternately stacked in the axial direction to form the piezoelectric stack which extends in the axial direction of the fuel injection valve ( 24 ) extends to the required offset of the control valve ( 52 ) required to perform the fuel injection function.

With the above construction, the control valve ( 52 ) in the state in which the piezoelectric elements by Stromlosschaltung the electric actuator ( 62 ) are contracted by the driving force of the valve spring ( 56 ) to communicate between the control valve receiving chamber ( 50 ) and the low-pressure fuel passage ( 54 ) and the connection between the control valve receiving chamber ( 50 ) and the high-pressure fuel passage ( 39 ) close. Consequently, the high-pressure fuel from the high-pressure fuel passage ( 39 ) through the mouth ( 48 ) to the pressure control chamber ( 46 ), so that the pressure, which of the high pressure fuel of the pressure control chamber ( 46 ) on the nozzle needle ( 42 ), and the pressure exerted by the high pressure fuel of the needle receiving chamber (FIG. 36 ) on the nozzle needle ( 42 ) is applied, basically become equal to each other. In this way, the nozzle needle ( 42 ) by the driving force of the needle spring ( 44 ) against the needle seat area ( 34 ) (Valve closure state of the fuel injection valve ( 24 )), wherein the needle spring ( 44 ) the nozzle needle ( 42 ) to the side of the fuel injection openings ( 30 ) of the fuel injection valve ( 24 ) presses. In this case, the fuel injection from the fuel injection openings ( 30 ) stopped.

In contrast, the control valve ( 52 ) in the state in which the piezoelectric elements are energized by the electrical actuator ( 62 ) are expanded against the driving force of the valve spring ( 56 ) offset to the connection between the control valve receiving chamber ( 50 ) and the high pressure fuel passage ( 39 ) and the connection between the control valve receiving chamber ( 50 ) under the low pressure fuel passage ( 54 ) close. As a result, the high pressure fuel of the pressure control chamber ( 46 ) through the mouth ( 48 ) and the control valve receiving chamber ( 50 ) to the low pressure fuel passage ( 54 ) issued. Then the pressure from the fuel of the pressure control chamber ( 46 ) on the nozzle needle ( 42 ) is applied lower than the pressure exerted by the high pressure fuel of the needle accommodating chamber ( 36 ) on the nozzle needle ( 42 ) is applied. If the force caused by the pressure difference between the fuel in the pressure control chamber ( 46 ) on the nozzle needle ( 42 ) applied pressure and the high pressure fuel of the needle accommodating chamber ( 36 ) on the nozzle needle ( 42 ) pressure applied is greater than the force exerted on the nozzle needle ( 42 ) towards the side with the fuel injection openings ( 30 ) of the fuel injection valve ( 24 ) is applied, the nozzle needle ( 42 ) from the needle seat area ( 34 ) in the Valve opening state of the fuel injection valve ( 24 ) lifted. The high pressure fuel is injected from the fuel injection openings ( 30 ) injected.

The fuel injection valve ( 24 ) having the structure described above is commonly referred to as a center-feed type fuel injection valve. The center-feed type fuel injection valve can significantly reduce (or eliminate) an amount of static leakage of fuel. The static loss leak refers to the fuel that always goes to the low-pressure fuel passage ( 54 ) through, for example, a gap opening in the fuel injection valve ( 24 ) is output in a state where the fuel injection valve ( 24 ) is kept in the valve closure state.

An electronic control unit (ECU) ( 64 ), which is also referred to as an electronic control device, is a control device (serving as a fuel injection control device) which controls various actuators required for different control operations of the battery type fuel injection system and which has a microcomputer and a memory (non-volatile memory) ( 64a ) includes. The ECU ( 64 ) receives signals from an accelerator pedal sensor ( 66 ), a coolant temperature sensor ( 68 ), an oil temperature sensor ( 70 ), an intake air temperature sensor ( 72 ) and an intake air pressure sensor ( 74 ). The accelerator pedal sensor (also called accelerator sensor) ( 72 ) detects an amount of operation of an accelerator (for example, an amount of depression of an accelerator pedal operated by a driver of the vehicle). The coolant temperature sensor ( 68 ) detects the temperature (coolant temperature) of the coolant that cools the engine. The oil temperature sensor ( 70 ) detects the temperature (oil temperature) of the engine oil. The intake air temperature sensor ( 72 ) detects the temperature of the air, the temperature of the combustion chamber ( 32 ) is supplied. The intake air pressure sensor ( 74 ) detects the pressure of the intake air leading to the combustion chamber ( 32 ) is fed. Furthermore, the ECU ( 64 ) Signals from an outside air temperature sensor ( 76 ), a speed sensor ( 78 ), a crank angle sensor ( 80 ), the fuel temperature sensor ( 20 ) and a fuel pressure sensor ( 25 ). The outside air temperature sensor ( 76 ) detects the temperature of the outside air. The vehicle speed sensor ( 78 ) records the driving speed of the vehicle. The crank angle sensor ( 80 ) detects the angle of rotation of the crankshaft ( 12 ). The ECU ( 64 ) controls combustion of the engine, such as the energy input to the intake air metering valve of the fuel pump ( 14 ) to control the rail pressure based on the input signal to a target rail pressure.

In particular, the ECU ( 64 ), the fuel injection control operation, the energization of the electric actuator ( 62 ) to deliver multiple fuel feeds (multiple fuel injections, ie, a plurality of fuel injections) from the fuel injection valve (FIG. 24 ) per combustion cycle at the corresponding cylinder, ie during a period of one combustion cycle (720 ° crank angle (CA)). In the present embodiment, the plurality of fuel injections per combustion cycle includes a pilot fuel injection and a main fuel injection. The pilot fuel injection is the injection of a very small amount of fuel (micro fuel injection) for the purpose of promoting the mixing of fuel and air immediately before ignition of such a mixture of fuel and air and limiting formation of nitrogen oxide (NOx) by shortening a delay in the ignition timing after the main fuel injection, whereby the combustion noise and vibration are reduced. In contrast, the main fuel injection causes the generation of the torque of the engine and provides a largest fuel injection amount within the plurality of fuel injections per combustion cycle.

Specifically, the fuel injection amount (a demand injection amount of the fuel injection valve) of the fuel injection valve (FIG. 24 ) required to achieve a target engine torque (required torque) for the one combustion cycle in a fuel amount calculating means (serving as a fuel amount calculating means) ( 64b ) of the ECU ( 64 ) based on the degree of operation of the accelerator pedal, which on the output value of the accelerator pedal sensor ( 66 ), and the engine speed calculated on the output value of the crank angle sensor ( 80 ). Next, in an assignment device (serving as an assignment means) ( 64c ) of the ECU ( 64 ) the demand injection amount (required injection amount) is divided into an injection amount of the pilot injection and an injection amount of the main injection, and each of these injection amounts (each divided injection amount) is expressed as a manipulated variable (a manipulated variable injection amount) of the injection amount of the fuel injection valve ( 24 ) set. Further, a time interval between an end timing of the pilot injection and a start timing of the next main injection is calculated based on the demand injection amounts of the engine speed and the coolant temperature (based on the coolant temperature on the output value of the coolant temperature sensor ( 68 ) is received). Then manipulated variable injection periods (drive signals) of the fuel injection valve ( 24 ) required for the execution of the multiple Fuel injection per combustion cycle are provided, calculated based on the manipulated variable injection quantities, the interval and the rail pressure (the rail pressure on the output value of the fuel pressure sensor ( 25 ). Based on the driver signals, the electric actuator ( 62 ) by a control device (serving as control means) ( 64e ) of the ECU ( 64 ) is energized to the fuel injection valve ( 24 ) and thereby opening each of the respective amounts of fuel corresponding to the demand injection amounts from the fuel injection ports ( 30 ) to carry out the multiple fuel injections per combustion cycle.

Each driver signal is usually calculated using a map which shows the relationship between the rail pressure and the fuel injection quantity in the fuel injection valve ( 24 ) shows. This map is usually created by a corresponding adaptation work (an experiment) under a reference temperature condition (for example the coolant temperature of 80 ° Celsius) and in the memory ( 64a) the ECU ( 64 ) filed.

When the temperature of the fuel passing through the high-pressure fuel passage ( 39 ), the viscosity of the fuel changes, possibly causing a deviation of the fuel injection amount of the fuel injection valve (FIG. 24 ) from a previously calculated quantity (an amount that was previously calculated at the time of the adjustment work). This is caused by a deviation of the temperature of the fuel passing through the high-pressure fuel passage ( 39 ) flows from the temperature corresponding to the reference temperature condition used at the time of adjustment work. When such a temperature change occurs, the fuel injection characteristic may change so that the fuel injection amount (FIG. Q ) increases in the low temperature region due to the increase in the fuel temperature and then decreases in the high temperature region as in 2 shown. With reference to the 3 to 6B Now, a mechanism of changing the fuel injection amount ( Q ) caused by the change in the fuel temperature of the high pressure fuel passing through the high pressure fuel passage ( 39 ) flows.

3 is an enlarged partial view of the fuel injection valve ( 24 ). In 3 the gap between the back pressure area ( 42c ), the nozzle needle ( 42 ) and the pressure chamber forming element ( 28 ) and the gap between the inner wall of the body ( 26 ) containing the needle receiving chamber ( 36 ), and the outer peripheral surface of the guide portion (FIG. 42b) shown on an enlarged scale. Furthermore, for simplicity, the needle spring ( 44 ) and the valve spring ( 56 ) not shown.

First, a mechanism for reducing the amount of fuel injection ( Q ) described due to the increase in the fuel temperature in a case where the fuel temperature is in the high temperature range. Here, the high temperature area refers to an area in which the degree of increase in the viscosity of the fuel caused by the decrease in the fuel temperature is moderate (flat slope) (cf. 4 ).

If the temperature of the fuel caused by the high pressure fuel passage ( 39 ) flows, increases, the viscosity (µ) of the fuel decreases. This increases the flow rate of the high-pressure fuel that flows from the high-pressure fuel passage ( 39 ) through the annular gap (river passage A ) between the back pressure area ( 42c ) and the pressure chamber formation element ( 28 ) in the pressure control chamber ( 46 ) flows. As the flow amount of the fuel increases, a pressure difference between the fuel pressure before the flow passage ( A ) and the fuel pressure after the river passage ( A ) small. Here, the viscosity (µ) of the fuel, the flow amount of the fuel, and the differential pressure are determined by the following equation (c1) with respect to the flow in the annular gap.

mit:

Q :=

Flussmenge eines Fluids, das durch den ringförmigen Spalt fließt.

Π :=

Kreiszahl / Ludophsche Zahl.

d :=

Innendurchmesser des ringförmigen Spalts.

h :=

Spaltweite (eine Größe des Spalts).

µ :=

Viskosität (absolute Viskosität) des Fluids.

L :=

Länge des ringförmigen Spalts.

P1 - P2 :=

Druckdifferenz zwischen dem Druck vor dem ringförmigen Spalt und dem Druck nach dem ringförmigen Spalt.

Equation c1: $$Q=\frac{\left(\pi *d*H^3\right)}{\left(12*\mu *L\right)}*\left(P1-P2\right)$$

With:

Q: =

Flow amount of a fluid flowing through the annular gap.

Π: =

Circular number / Ludoph's number.

d: =

Inner diameter of the annular gap.

h: =

Gap width (a size of the gap).

μ: =

Viscosity (absolute viscosity) of the fluid.

L: =

Length of the annular gap.

P1 - P2: =

Pressure difference between the pressure before the annular gap and the pressure after the annular gap.

5A and 5B are schematic diagrams showing the annular gap. In particular is 5A a plan view showing a model of the annular gap. 5B is a cross-sectional view according to the section line VB-VB in 5A ,

With another reference to 3 occurs in a case where the fuel injection valve increases in the flow amount of the fuel that enters the pressure control chamber ( 46 ) flows, is opened or closed, the following phenomenon occurs.

When the operating state of the fuel injection valve is changed from the valve closing state to the valve opening state, that is, when the pressure control chamber (FIG. 46 ) with the low-pressure fuel passage ( 54 ), the amount of fuel passing through the flow passage ( A ) into the pressure control chamber ( 46 ) flows, increases. In this case, the rate of decrease of the pressure of the pressure control chamber ( 46 ) and the speed of movement of the nozzle needle ( 42 ) of the needle seat portion in the Abhubrichtung the nozzle needle ( 42 ) is reduced. At this time, the opening timing of the fuel injection valve ( 24 ) and the fuel injection amount ( Q ) from the fuel injection valve ( 24 ) is reduced.

In contrast, when the operating state of the fuel injection valve is changed from the valve opening state to the valve closing state, that is, when the pressure control chamber ( 46 ) with the high pressure fuel passage ( 39 ) is connected, the amount of the fuel discharged from the high-pressure fuel passage through the flow passage (the flow passage B) which passes through the control valve accommodating chamber ( 50 ) and the mouth ( 48 ) extends into the pressure control chamber ( 46 ) flows. As a result, the speed of movement of the nozzle needle ( 42 ) in the valve seat direction of the nozzle needle ( 42 ) against the needle seat area ( 34 ) increases as the rate of pressure increase of the pressure control chamber ( 46 ) gets higher. The valve closure timing of the fuel injection valve ( 24 ) accelerated, ie shifted to an earlier point in time, and the fuel injection quantity ( Q ) from the fuel injection valve ( 24 ) decreased.

When the fuel temperature is raised by the mechanism described above, the fuel injection amount ( Q ) in the high-temperature region in the fuel injection valve (FIG. 24 ) for the same driver signal.

When the fuel temperature rises, the fuel injection amount ( Q ) due to a change in the flow velocity of the fuel passing through the annular gap (the flow passage C ) between the distal end region ( 42a) and the needle seat area ( 34 ) immediately after the start of lifting the nozzle needle ( 42 ) from the needle seat area ( 34 ) by the valve opening operation of the fuel injection valve (FIG. 24 ) flows.

That is, when the flow amount of the fuel through the flow passage ( C ) flows, increases, the pressure increases, which against the lower end of the nozzle needle ( 42 ) is affected due to the drop in the pressure difference between the pressure of the fuel before the flow passage ( C ) and the pressure of the fuel after the flow passage ( C ). As a result, the speed of movement of the nozzle needle ( 42 ) in the lifting direction thereof away from the needle seat area ( 34 ) is increased and the fuel injection quantity ( Q ) elevated. In any case, a degree of shift in the fuel injection amount ( Q ) towards the rising side of the river through the influence of the river passage ( C ) is less than a degree of shift in the fuel injection amount ( Q ) towards the sloping side, which is influenced by the flow passages ( A ) and ( B ) is caused. As a result, the fuel injection amount ( Q ) decreased in the high pressure temperature range as the fuel temperature rises.

Next, a mechanism for reducing the amount of fuel injection ( Q ) described due to the drop in the fuel temperature in the case where the fuel temperature is shifted in the low pressure region. Here, the low pressure area refers to a range in which a degree of the increase in the viscosity of the fuel caused by the decrease in the fuel temperature is steep (cf. 4 ).

When the temperature of the fuel flowing through the high-pressure fuel passage ( 39 ), becomes excessively low, the fuel injection quantity decreases ( Q ) due to the influence of the annular gap (the river passage D ) between the outer peripheral surface of the guide portion (FIG. 42b ) and the inner wall of the body ( 26 ) containing the needle receiving chamber ( 36 ), due to a sharp increase in the viscosity (μ) of the fuel.

In the state in which the operating state of the fuel injection valve is changed from the valve-opening state to the valve-closing state, the flow amount of the fuel discharged from the high-pressure fuel passage (FIG. 39 ) through the flow passages (A, B) into the pressure control chamber ( 46 ), and thereby the rate of rise of the pressure of the pressure control chamber ( 46 ) decreased.

When the viscosity of the fuel becomes excessively high, the degree of decrease in the flow amount of the fuel passing through the flow passage (FIG. D ) flows, however, large, so that the degree of decrease in the fuel pressure at the distal End area ( 42a ) becomes sufficiently higher than the degree of decrease in the pressure of the pressure control chamber (FIG. 46 ). In particular, the length of the guidance area ( 42b ) (the axial length of the guide area ( 42b )) in the axial direction of the fuel injection valve ( 24 ) to increase the operational stability of the nozzle needle ( 42 ). As a result, the pressure difference between the pressure of the fuel before the flow passage ( D ) and the pressure of the fuel after the flow passage ( D ), and the degree of decrease in the fuel pressure at the distal end portion ( 42 ) to grow up.

When the degree of decrease in pressure at the distal end portion (FIG. 42a ) becomes larger than the degree of decrease in the pressure of the pressure control chamber (FIG. 46 ), a pressure difference between the pressure at the upper end of the nozzle needle ( 42 ) and the pressure at the lower end of the nozzle needle ( 42 ) large. The speed of movement of the nozzle needle ( 42 ) in the seat direction thereof to the needle seat portion (FIG. 34 ) increased. The valve closure timing of the fuel injection valve ( 24 ) accelerates, that is shifted to an earlier time and thereby the fuel injection amount ( Q ) of the fuel injection valve ( 24 ) decreased.

When the fuel temperature is decreased by the mechanism described above, the fuel injection amount ( Q ) in the low temperature range for the fuel injection valve ( 24 ) reduced for the same driver signal.

The length (L) is conceivable 5B the management area ( 42 ) (the axial length of the guide area ( 42b ) in the axial direction of the fuel injection valve ( 24 )) in order to weaken the influence of the deviation in the injection characteristic caused by the influence of the flow passage ( B ) is caused in the low temperature range. However, using such an approach is difficult. This is due to the fact that it is difficult to provide alternative means that can improve the operational stability of the nozzle needle ( 42 ) for the fuel injection valve ( 24 ) ensure the present embodiment. It is difficult to ensure operational stability here by increasing the axial length of the back pressure area ( 42c ) in the axial direction of the fuel injection valve ( 24 ) to ensure. This follows, for example, that the coaxiality required for the operation of the nozzle needle ( 42 ) is necessary due to the shaping of the body ( 26 ) and the pressure chamber formation element ( 28 ) cannot be guaranteed as separate parts.

6A and 6B show an example of the change in the fuel injection amount (injection rate) per unit time in the fuel injection valve ( 24 ) caused by a change in the temperature of the fuel caused by the high pressure fuel passage ( 39 ) flows. 6A shows in particular the change in the driver signal that is sent to the electrical actuator ( 62 ) is fed and 6B shows the change in the fuel injection rate in the fuel injection valve ( 24 ).

In the in 6A and 6B The example shown shows a change in the fuel injection rate from a waveform represented by a solid line to a waveform shown in FIG 6 is shown by a dashed line, shifted when the temperature of the fuel decreases in the high pressure region. This follows from the acceleration of the valve opening timing of the fuel injection valve ( 24 ) and the delay of the valve closing timing of the fuel injection valve ( 24 ).

When the fuel temperature is further decreased to change from the high temperature range to the low temperature range, the injection rate is shifted from the waveform shown by the broken line to the waveform shown by a chain line in FIG 6B is shown. This is due to the fact that the valve opening timing of the fuel injection valve ( 24 ) is accelerated further and the valve closure timing of the fuel injection valve ( 24 ) changes from the delayed side to the accelerated side.

In order to compensate for the deviation in the injection characteristic caused by the change in the fuel temperature, a correction operation of the manipulated variable injection quantity in the present exemplary embodiment is carried out based on an estimated value (also referred to as an estimated value) of the temperature of the fuel, which is caused by the high pressure Fuel passage ( 39 ) flows.

7 FIG. 15 shows the correction operation of the manipulated variable injection amount in the present embodiment. This processing is performed, for example, at a predetermined cycle by a correction device ( 64d) the ECU ( 64 ).

First is at step S10 the temperature (INJ inlet fuel temperature T _in ) of the fuel flowing _into the fuel inlet ( 40 ) entry. In the present embodiment, the INJ inlet fuel temperature T _{in pmp} based on the pump inlet fuel temperature T based on the output value of the fuel temperature sensor ( 20 ) and the degree of change in the fuel temperature estimated by the heat exchange between the fuel and the outside (the environment) (in the fuel flow path from the inlet of the fuel pump ( 14 ) to the fuel inlet ( 40 )). Specifically, the degree of change in the fuel temperature is defined such that the temperature-increasing side has a positive value and the INJ intake fuel temperature T _{in is} calculated as a sum of the pump inlet fuel _temperature T _pmp and the fuel _temperature change amount described above.

Here, the amount of change in the fuel temperature is calculated based on the following parameters [A] to [D].

Energy On

The energy A is the fuel through the compression of the fuel by means of the plunger in the fuel pump ( 14 ) added energy. As the energy On increases, the amount of increase in the fuel temperature is increased. The energy Ein can be defined as an energy obtained in a case where the compression of the fuel by the plungers is assumed to be adiabatic compression. Furthermore, the energy An may be obtained, for example, based on the rotational speed of the engine and the rail pressure.

Coolant temperature T _Hw

As the coolant temperature T _Hw rises, the heat emitted from the engine body to the fuel line and the common rail ( 18 ) is directed to an increase and the amount of change in the fuel temperature tends to increase.

Outside air temperature T _air

As the outside _air temperature T _air rises, the fuel temperature change amount is increased because the heat transferred from the environment around the fuel flow path, for example, through the pipe to the fuel in the fuel flow, during the time of flow through the fuel flow path from the fuel pump ( 14 ) to the fuel inlet ( 40 ) tends to increase. The outside air temperature can be based, for example, on the output value of the outside air temperature sensor ( 76 ) be calculated.

Vehicle driving speed SPD

As the vehicle traveling speed SPD increases, the amount of air applied to the line directing the fuel tends to increase in the traveling vehicle, resulting in an increase in the rate of change of the fuel temperature change level. For example, the vehicle traveling speed SPD may be based on the output value of the vehicle speed sensor (FIG. 78 ) be calculated.

Next, at the steps S12 to S16 the temperature (the INJ internal fuel temperature Tij) of the fuel passing through the high pressure fuel passage ( 39 ) flows. In the present embodiment, it is assumed that the INJ internal fuel temperature Tij is the fuel temperature at the junction (a position α of 3 hereinafter referred to as an estimated position α) between the fuel passage (FIG. 38 ) and the needle receiving chamber ( 36 ) at the high-pressure fuel passage ( 39 ). The high pressure fuel passing through this position passes through the flow passages A to D of FIG 3 such that the temperature of the fuel at the estimation position α and the fuel injection characteristic of the fuel injection valve (FIG. 24 ) can be reasonably corrected.

The internal fuel temperature Tij in INJ is estimated as the sum of the INJ inlet fuel temperature T _in , the amount of change in the temperature of the fuel (hereinafter referred to as the internal fuel temperature change amount ΔT), which is caused by the heat exchange between the high pressure fuel and the fuel injection valve ( 24 ) via the fuel flow path from the fuel inlet ( 40 ) to the estimated position α. Here, the internal fuel temperature change amount ΔT is a value that is defined such that the temperature rise side has a positive value.

At step S12 In particular, a dwell period correspondence value (hereinafter referred to as a dwell time t _long ) is calculated which corresponds to a residence time of the fuel in the fuel injection valve (FIG. 24 ) since a time of entering the fuel injection valve ( 24 ) through the fuel inlet ( 40 ) corresponds. In the present embodiment, the dwell time t _{long is} defined as a period of time presumed necessary for the fuel to be exhausted from the fuel inlet (FIG. 40 ) to the estimation position α. The residence time t _long is based on a volume V of the high-pressure fuel passage ( 39 ) from the fuel inlet ( 40 ) to the estimation position α, the demand injection amount Q _total , a dynamic _leak amount Q _leak, and a time corresponding to a combustion cycle (720 ° crank angle (CA)) calculated based on the engine rotation speed. Specifically, the residence time t _long is further calculated by multiplying a value obtained by dividing the volume V by a sum of the demand injection amount Q _total and the amount Q _{leak of} the dynamic loss with the time period corresponding to a combustion cycle (720 ° crank angle duration (CA)).

The dynamic loss relates to the fuel coming out of the pressure control chamber ( 46 ), for example through the mouth ( 48 ) and the control valve receiving chamber ( 50 ) to the low pressure fuel passage ( 54 ) due to the movements of the nozzle needle ( 42 ) and the control valve ( 52 ) is output at the time of fuel injection.

After that, at step S14 the temperature (an INJ inner wall temperature T _body , which is the temperature at the inner wall of the high-pressure fuel passage ( 39 ) is) of the fuel injection valve ( 24 ). In the present embodiment, the INJ inner wall temperature T _{body is} calculated based on external parameters and internal parameters. The external parameters are parameters set at the INJ inner wall temperature T _body for the evaluation of the influence of the heat exchange between the fuel injection valve ( 24 ) and the outdoor area (the environment). The internal parameters are parameters used to evaluate the influence of heat generation in the fuel injection valve at the INJ interior wall temperature T _body . Specifically, in the present embodiment, the external parameters include the following parameters [E] to [H], and the internal parameters include the following parameters [I].

Coolant temperature T _Hw

Since the fuel injection valve ( 24 ) touches the engine body, the coolant temperature T _{Hw is} a reference parameter that is used to calculate the INJ interior wall temperature T _body . In particular, the INJ inner wall temperature T _body tends to increase as the coolant temperature T _Hw rises.

combustion heat

As the heat of combustion increases, the heat entering the fuel injection valve (FIG. 24 ), which enters the combustion chamber ( 32 protrudes, and thereby the INJ inner wall temperature T _body tends to increase. For example, the heat of combustion may be evaluated based on the demand injection amount.

Intake air temperature T _s

As the intake air temperature T _s drops, a degree of cooling of the fuel injection valve ( 24 ) into the combustion chamber ( 32 ) protrudes, and the INJ interior wall temperature T _body tends to decrease. The intake air temperature T _s can be based, for example, on the output value of the intake air temperature sensor ( 72 ) be calculated.

Intake air pressure P _s

When the intake air pressure P _s changes, possibly depending on the combustion state in the combustion chamber ( 32 ) change the heat of combustion. As a result, the intake air pressure P _{s can be used} as an external parameter. The intake air pressure P _s may be, for example, based on the output value of the intake air pressure sensor (FIG. 74 ) be calculated.

Q _leak amount of dynamic loss and rail pressure P _r

In the case where the fuel injection valve ( 24 ) is placed in the valve open state, the high pressure fuel from the pressure control chamber ( 46 ) to the low pressure fuel passage ( 54 ) spent. A choke area (throttle area) which, compared to its adjacent areas, has a passage area with a reduced cross section, consists in the fuel flow path from the pressure control chamber ( 46 ) to the low pressure fuel passage ( 54 ). As a result, the fuel is released from pressure when the high-pressure fuel passes through the choke area and the flow rate of the fuel is significantly increased. The fuel, which has the increased flow velocity, swirls the gas around it, so that heat is generated. This heat is increased as the amount Q _leak of dynamic loss increases or when the rail pressure P _{r is} increased. Therefore, the amount Q _{leak of} the dynamic loss and the rail pressure P _{r can be used} as internal parameters. Here the quantity Q _{leak of} the dynamic loss can be assessed with reference to the operating state of the engine.

Furthermore, the oil temperature T _{oil can be used} as an external parameter that has a positive relationship with the coolant temperature T _Hw and is higher than the coolant temperature T _Hw . When the oil temperature T _{Oil is used in} addition to the coolant temperature T _Hw , the influence of heat from the engine body to the fuel injection valve ( 24 ) is directed to the INJ interior wall temperature. Here, the oil temperature T _{Oil can} be based, for example, on the output value of the oil temperature sensor ( 70 ) be calculated.

Furthermore, a parameter can be used as an internal parameter, which can be used for evaluating an influence of the heat that is generated as a result of the piezoelectric stack being energized by the piezoelectric stack.

Next, at step S16 the INJ internal fuel temperature T _ij is estimated based on the INJ inlet fuel temperature T _in , the INJ interior wall temperature T _body, and the residence time t _long . This estimate is based on the fact that the temperature (the INJ inlet fuel temperature T _in ) of the fuel entering the fuel inlet ( 40 ), which approaches the INJ inner wall temperature T _body and finally reaches the INJ inner wall temperature T _body , as in 8th is shown.

Specifically, in a case where the INJ intake fuel temperature T _{in is} lower than the INJ inner wall temperature T _body when a temperature difference between the INJ intake fuel temperature T _in and the INJ inner wall temperature T _body increases, or when the residence time t _{long is} increased , the internal fuel temperature change amount ΔT tends to increase and the INJ internal fuel temperature Tij also tends to increase.

Now, a specific estimation method of the INJ internal fuel temperature Tij will be described. First, the internal fuel temperature change amount ΔT is calculated using a map defining the internal fuel temperature change amount ΔT in relation to the residence time t _long and the temperature difference between the INJ inner wall temperature T _body and the INJ intake fuel temperature T _in . Then, the INJ internal fuel temperature T _{ij is} estimated as a sum of the internal fuel temperature change amount ΔT and the INJ intake fuel temperature T _in .

Alternatively, the INJ internal fuel temperature T _{ij can be} estimated using a map or a mathematical equation in which the INJ internal fuel temperature T _{ij is} in relation to the INJ inlet fuel temperature T _in , the INJ inner wall temperature T _body and the dwell time t _long .

Referring back to the description of 7 becomes at step S18 a correction amount ΔQ of the manipulated variable injection amount for each of the plurality of fuel injections, that is, calculated for both the pilot fuel injection and the main fuel injection based on the INJ internal fuel temperature T _ij . The reason for calculating the correction amount ΔQ of the manipulated variable injection amount for each of the plural fuel injections is to improve the correction accuracy of the fuel injection amount. In particular, due to the change in the INJ internal fuel temperature T _ij, each of the multiple fuel injections per combustion cycle may possibly deviate from the corresponding amount originally calculated at the time of the adaptation work. It should be noted that not necessarily each of the multiple fuel injections per combustion cycle deviates by the same rate. In particular, the amount of deviation in the fuel injection amount may vary depending on the drive signal (target injection period). Accordingly, in the case where the demand injection amount is corrected, and thereafter the corrected demand injection amount is divided into the corresponding injection quantities, each of which is then assigned to a corresponding one of the plurality of fuel injections of the combustion cycle, injection precision of each of the multiple fuel injections may be degraded.

In view of the above points, the correction accuracy of a fuel injection amount can be improved if the correction amount ΔQ is calculated for each of the plurality of fuel injections of the combustion cycle.

Now, a calculation method of the correction amount ΔQ will be described. With reference to 9 may use a map in which the fuel injection quantity Q is correlated with the driver signal, the rail pressure and the INJ internal fuel temperature T _ij , a difference between the manipulated variable injection amount Q _t , which to a reference temperature (in 9 is specified as a temperature adjacent to a boundary between the low-temperature region and the high-temperature region) and the fuel injection amount corresponding to the estimated INJ internal fuel temperature T _ij for each of the multiple fuel injections of a combustion cycle are calculated as the correction amount ΔQ. In this case, the reference temperature the INJ internal fuel temperature T _ij at the estimation position α at the time of adjusting the injection characteristic of the fuel injection valve (FIG. 24 ) (at the time of implementation of the reference temperature condition). Specifically, the correction amount ΔQ may be further calculated by subtracting the fuel injection amount corresponding to the estimated INJ internal fuel temperature T _ij from the manipulated variable injection amount Q _t corresponding to the reference temperature. In this type of correction operation, the correction amount ΔQ is increased as the INJ internal fuel temperature T _ij in the high-temperature region increases or when the INJ internal fuel temperature T _ij lowers in the low-temperature region.

The above map is the information indicating that the fuel injection amount Q is decreased as the INJ internal fuel temperature T _ij in the high temperature region increases, and that the fuel injection amount Q is decreased when the INJ internal fuel temperature T _ij lowers in the low temperature region , The map is in advance in memory ( 64a) stored.

Referring back to the explanation of the 7 will at step S20 a final manipulated variable injection quantity (a corrected injection quantity) Q _{tfin of} the fuel for each of the plurality of fuel injections of a combustion cycle by adding the corresponding correction quantity ΔQ to the manipulated variable injection quantity Q _t of each of the plurality of fuel injections. Then, the majority of the fuel injections per combustion cycle based on the final manipulated variable injection _amount Q _tfin of each of the plurality of fuel injections by controlling the power supply of the electric actuator ( 32 ) by the control device (the control means) ( 64e ) the ECU ( 64 ) executed.

When processing step S20 is completed, the series of processing described above is terminated.

1. (1) Die INJ interne Kraftstofftemperatur T_ij wird basierend auf der INJ Einlass-Kraftstofftemperatur T_in der INJ Innenwandtemperatur T_body und der Verweilzeitdauer t_long berechnet. Die Korrekturoperation wird ausgeführt, um die Stellgrößen-Injektionsmenge Q_t des Kraftstoffinjektionsventils (24) basierend auf der geschätzten INJ internen Kraftstofftemperatur T_ij zu korrigieren. Auf diese Weise ist es möglich, das Auftreten der Abweichung in der Kraftstoff-Injektionsmenge bei dem Kraftstoffinjektionsventil (24) von der ursprünglich bei dem Zeitpunkt der Anpassungsarbeit vorherbestimmten Menge, welche durch die Veränderung in der INJ internen Kraftstofftemperatur T_ij hervorgerufen ist, zu begrenzen (limitieren). Das bedeutet, es ist möglich, eine Verschlechterung in einer Einstellungsgenauigkeit der Kraftstoff-Injektionsmenge bei dem Kraftstoffinjektionsventil (24) in angemessener Weise zu begrenzen.
2. (2) Die Stellgrößen-Injektionsmenge Q_t von jeder der mehreren Injektionen, also von sowohl der Pilot-Kraftstoffinjektion und der Haupt-Kraftstoffinjektion wird korrigiert. Dabei ist es möglich, die Korrekturgenauigkeit der Kraftstoff-Injektionsmenge bei dem Kraftstoffinjektionsventil (24) zu verbessern.
3. (3) Das Kraftstoffinjektionsventil des center-feed Typs, das den piezoelektrischen Stack aufweist, wird als das Kraftstoffinjektionsventil (24) benutzt. In dem Fall, bei dem das Kraftstoffinjektionsventil den piezoelektrischen Stack aufweist, wird angestrebt, die Hochdruck-Kraftstoffpassage (39a) lang zu gestalten, und dabei neigt die INJ interne Kraftstofftemperatur T_ij zu Änderungen. Unter derartigen Umständen verursacht der Führungsbereich (42b), der an der Düsennadel (42) vorgesehen ist, den Anstieg in der Abweichung der Kraftstoff-Injektionsmenge, welcher durch die Änderung in der INJ internen Kraftstofftemperatur T_ij induziert ist. In dem Fall des vorliegenden Ausführungsbeispiels, bei dem das Kraftstoffinjektionsventil (24), das dazu neigt, eine hohe Abweichung in der Kraftstoff-Injektionsmenge infolge der Veränderung der INJ internen Kraftstofftemperatur T_ij aufzuweisen, ist die obige Korrekturoperation demzufolge in hohem Maße nützlich.

The present embodiment offers the following advantages.

1. (1) The INJ internal fuel temperature T _ij is calculated based on the INJ intake fuel temperature T _in the INJ inner wall temperature T _body and the dwell time t _long . The correction operation is carried out to determine the manipulated variable injection quantity Q _{t of} the fuel injection valve ( 24 ) based on the estimated INJ internal fuel temperature T _ij . In this way, it is possible to prevent the occurrence of the deviation in the fuel injection amount in the fuel injection valve ( 24 ) from the amount originally determined at the time of the adaptation work, which is caused by the change in the INJ internal fuel temperature T _ij . That is, it is possible to see deterioration in a fuel injection quantity adjustment accuracy in the fuel injection valve ( 24 ) limit appropriately.
2. (2) The manipulated variable injection amount Q _t of each of the multiple injections, that is, both of the pilot fuel injection and the main fuel injection, is corrected. It is possible to correct the accuracy of the fuel injection quantity in the fuel injection valve ( 24 ) to improve.
3. (3) The center-feed type fuel injection valve having the piezoelectric stack is called the fuel injection valve ( 24 ) used. In the case where the fuel injection valve has the piezoelectric stack, the aim is to make the high pressure fuel passage (39a) long, and the INJ internal fuel temperature T _ij tends to change. Under such circumstances, the guide area (42b) which is attached to the nozzle needle ( 42 ) is provided, the increase in the deviation of the fuel injection quantity, which is induced by the change in the INJ internal fuel temperature T _ij . In the case of the present embodiment in which the fuel injection valve ( 24 ) which tends to have a large deviation in the fuel injection amount due to the change in the INJ internal fuel temperature T _ij , the above corrective operation is therefore highly useful.

In the above embodiment, the step S12 of the 7 to a dwell time calculating means (serving as a dwell period calculating means) of the correcting means ( 64d ) of the ECU ( 64 ) correspond and step S16 from 7 may be supplied to a fuel temperature estimating means (serving as a fuel temperature estimating means) of the correcting means (FIG. 64d ) correspond. Furthermore, steps can S18 and S20 of the 7 to a correction device (serving as a correction means) of the correction device ( 64d ) correspond.

The above embodiment may be modified as follows.

The fuel injection valve of the present disclosure is not limited to the fuel injection valve that functions as an electric actuator ( 62 ) has the piezoelectric stack. For example, the fuel injection valve of the present disclosure can be used as the electric actuator ( 62 ) have an electromagnetic coil. If the electrical actuator ( 62 ) and the fuel passage ( 38 ) are generally parallel to each other and in the direction perpendicular to the axial direction of the fuel injection valve (that is, perpendicular to the central axis of the fuel injection valve ( 24a )) are arranged one behind the other, even in such a case the high-pressure fuel passage ( 39a ) to be extended to cause the change in the INJ internal fuel temperature T _ij . Accordingly, the present disclosure can be effectively applied to such a fuel injection valve.

Further, the fuel injection valve of the present disclosure may be a fuel injection valve that does not have the pressure control chamber and in which the nozzle needle is directly driven by the electric actuator. Even in such a case, the adjustment accuracy of the fuel injection amount at the time of valve opening of the fuel injection valve possibly due to the presence of the river passage (C), which in 3 is shown to be degraded. Accordingly, the present disclosure can be effectively applied in such a case. In the above embodiment, the center-feed type fuel injection valve is employed. However, the present disclosure is not limited to such a fuel injection valve. As in 10 For example, it is possible to use a fuel injection valve ( 24a ) of the side-feed type, in which a fuel passage ( 38a ) directly to an area (a needle receiving chamber ( 36a )) adjacent to a distal end region (Fig. 82a ) of the nozzle needle ( 82 ) is arranged. Hereinafter, the formation of this fuel injection valve ( 24a ) in greater detail. In the modification according to 10 those are the components that come with those from the 1 are identical, by the same reference numerals and those components with those of 1 are indicated by the same reference numbers with the appendix of the letter "a".

The high pressure fuel entering the fuel inlet ( 40a ) is fed through an input port (also referred to as an input side port) (84) to a pressure control chamber (FIG. 46a ) of the fuel injection valve ( 24a ).

The pressure control chamber ( 46a ) is connected to a low-pressure fuel passage ( 54 through an exit port (also referred to as a discharge side port) ( 86 ) connectable. The pressure control chamber ( 46a ) and the low-pressure fuel passage ( 54 ) are controlled by a control valve (valve element ( 52a )) and separated from each other. That means, when the discharge port ( 86 ) by the control valve ( 52a ) is closed, the pressure control chamber ( 46a ) and the low-pressure fuel passage ( 54 ) separated from each other. When the discharge port ( 86 ) by the control valve ( 52a) in contrast, the pressure control chamber ( 46a ) and the low-pressure fuel passage ( 54 ) connected with each other.

The control valve ( 52a ) receives from a valve spring ( 56a ) a force against the discharge mouth ( 86 ) in a closing direction of the control valve ( 52a ) for closing the discharge mouth ( 86 ).

Furthermore, the control valve ( 52a ) by the electromagnetic coil acting as an electrical actuator ( 62a ) is provided, displaceable. When the control valve ( 52a ) is attracted by the electromagnetic force of the electromagnetic coil, the control valve ( 52a ) from the outer mouth ( 86 ) offset in the valve opening direction to the outer opening ( 86 ) to open.

With such an arrangement, in a state in which the electromagnetic coil is not energized, and accordingly, the attracting force is not generated by the electromagnetic coil, the discharge port ( 86 ) by the control valve ( 52a ) with the force of the valve spring ( 56a ) locked. As a result, the pressure generated by the high-pressure fuel in the control chamber ( 46a ) against the nozzle needle ( 82 ), and the pressure exerted by the high pressure fuel in the needle receiving chamber (FIG. 36a ) against the nozzle needle ( 82 ) is applied, basically the same. So the fuel injection valve ( 24a ) by the force of the needle spring ( 44a ), which the nozzle needle ( 82 ) against the fuel injection openings ( 30a ) urges, put in the valve closure state.

In contrast, the control valve ( 52a ), when the electromagnetic coil is energized to generate the attracting force, offset in the valve opening direction to the output port ( 86 ) to open. In this case, the high-pressure fuel of the pressure control chamber ( 46a ) through the discharge mouth ( 86 ) to the low pressure fuel passage ( 54 ). As a result, the pressure generated by the high-pressure fuel of the pressure control chamber (FIG. 46a ) on the nozzle needle ( 42 ) is less than the pressure exerted by the high-pressure fuel of the needle receiving chamber ( 36a ) on the nozzle needle ( 82 ) is affected. When the force caused by this pressure difference becomes greater than the force exerted by the needle spring ( 44a ) on the nozzle needle ( 82 ) is applied to the nozzle needle ( 82 ) against the side of the fuel injection openings ( 30a ), the nozzle needle ( 82 ) and thereby the fuel injection valve ( 24a ) is placed in the valve opening state.

When like in 11 illustrated fuel injection valve ( 24a ) of the side-feed type here, the fuel injection amount Q at the fuel injection valve ( 24a ) decreases as the INJ internal fuel temperature T _ij increases. This deviation in the injection characteristic is due to the fact that the high-pressure fuel passage ( 39a ) is not reduced by the part that corresponds to the guide area, and there is none through the flow passage (D) of 3 caused influence in the low temperature range.

The INJ internal fuel temperature T _ij can, for example, the fuel temperature in the pressure control chamber ( 46a ) that are in the fuel injection valve ( 24a ) acts as the passage. In such a case, the dwell time t _{long can be,} for example, an interval between a first main fuel injection and the following main fuel injection. This is due to the following reason. That is, at the time the main fuel injection is performed, much of the fuel is in the pressure control chamber ( 46a ) to the side of the low pressure fuel passage ( 54 ) spent. As a result, the internal fuel temperature change amount ΔT can be initialized. Furthermore, the amount of a static loss can be used in the calculation of the dwell time t _long .

In the present embodiment, the various parameters including the coolant temperature T _{Hw are} used to estimate the INJ inlet temperature T _in . For example, it can be provided a sensor which directly detects the INJ inlet fuel temperature T _in, to the inlet temperature T INJ-sensing _in to. Furthermore, the above sensor, for example, on the common rail ( 18 ), the high-pressure line ( 22 ) or the fuel inlet ( 40 ) of the fuel injection valve ( 24 ) be provided.

The calculation method of the residence time t _long is not limited to the example discussed in the above embodiment. For example, a flow rate sensor that detects a flow rate of the fuel in the high-pressure fuel passage (FIG. 39 ), be provided and a distance of the fuel inlet ( 40 ) to the estimation position α may be divided by a flow velocity that will hold from an output value of the flow velocity sensor to obtain the residence time t _long .

The INJ interior wall temperature T _body estimation method is not limited to the example discussed in the above embodiment. For example, it is possible to use an alternative method of estimating the INJ interior wall temperature T _body that uses at least the coolant temperature T _Hw without using all of the parameters explained in the above exemplary embodiment as the external parameters. Furthermore, for example, an exhaust gas temperature sensor can be provided in an exhaust passage of the engine, and the INJ inner wall temperature T _body can be estimated based on a heat of combustion that is calculated based on an exhaust gas temperature that is obtained based on an output value of the exhaust gas sensor.

In the above embodiment, the situation is explained in which the INJ internal combustion temperature T _{ij increases} with time. However, the present disclosure can also be appropriately applied in a situation where the INJ internal fuel temperature T _ij drops with time.

The number of multiple fuel injections per combustion cycle is not limited to the two fuel injections that include the main fuel injection and the minimum quantity fuel injection (e.g., the pilot fuel injection) that is performed before the main fuel injection. The minimum quantity fuel injection can be carried out, for example, two or more times before the main fuel injection is carried out. Alternatively, one or more small amount fuel injections can be performed after the main fuel injection.

The engine is not limited to the compression-ignition type internal combustion engine, and may be, for example, a spark-ignition internal combustion engine (gasoline engine). In such a case, an electric pump and a supply line are provided in the fuel injection system. The electronic pump sucks the fuel (gasoline) from the fuel tank and discharges the soaked fuel. The supply line receives the fuel pumped from the electric pump and stores the received fuel in the high pressure state.

Furthermore, the engine is not limited to the engine that uses the fossil fuel. For example, the engine may be an engine that uses an alcohol fuel (e.g., ethanol, methanol) or a mixture fuel of the fossil fuel and an alcohol fuel. Further advantages and modifications will easily occur to the person skilled in the art. Accordingly, the present disclosure, in its broader understanding, is not limited to the specific details, representative device, and illustrative examples that have been shown and described.

Claims (12)

A fuel injection control device for a fuel injection system of an internal combustion engine, comprising an accumulator (18) adapted to accumulate fuel in a high pressure state, a fuel pump (14) for supplying fuel from a fuel tank (10) to the accumulator (18). is formed, and a Kraftstoffinjektionsventil (24,24a), which is adapted to receive the fuel accumulated in the accumulator (18) and a fuel inlet (40,40a) and a nozzle needle (42,82), wherein the fuel inlet (40 , 40a) receives the fuel supplied from the accumulator (18) and the nozzle needle (42, 82) is designed to open and close a fuel injection opening (30, 30a) of the fuel injection valve (24, 24a), characterized in that Residence time calculating means (S12) adapted to provide a dwell period correspondence value (t _long ) calculated at a residence time of the fuel in the fuel injection valve (24,24a) since a time of Entering the fuel injection valve (24, 24a) through the fuel inlet (40, 40a), based on: ◦ a volume V of the high pressure fuel passage (39) from the fuel inlet (40) to an estimated position α; ◦ a fuel injection amount (Q _total ) to be injected from the fuel injection valve (24,24a) per combustion cycle of the internal combustion engine. (Q _leak ) amount of dynamic loss related to the fuel discharged from the fuel injection valve (24) through a low pressure Fuel passage (54) is discharged to a fuel tank (10) due to the movement of the nozzle needle (42) at the time of fuel injection ◦ a period of time corresponding to a combustion cycle; wherein a fuel temperature estimation means (S16) is provided which is adapted to estimate a fuel temperature (T _ij ) in the fuel injection valve (24,24a), based on ◦ a difference between the temperature (T _body ) of the fuel injection valve (24 , 24a) and a fuel temperature (T _in ) of the fuel that has entered the fuel inlet (40, 40a); and ◦ the dwell period correspondence value (t _long ) calculated by the dwell period calculating means (S12), wherein correction means (S18, S20) adapted to supply an injection amount (Q _t ) from the fuel injection valve (S) 24,24a) fuel to be injected based on the fuel temperature (T _ij ) estimated by the fuel temperature estimation means (S16); and - wherein a control device (64e) is provided, which is _adapted to control a power supply of the fuel injection valve (24,24a) based on a corrected fuel injection amount (Q _tfin ), which is corrected by the correcting means (S18, S20). Fuel injection control device according to Claim 1 characterized in that the fuel injection valve (24, 24a) includes: a needle receiving chamber (36, 36a) formed by an inner wall of the fuel injection valve (24, 24a) and in which the nozzle needle (42, 82) is received; - A fuel passage (38,38a) which communicates between the needle accommodating chamber (36,36a) and the fuel inlet (40,40a); - A pressure control chamber (46,46a) which applies a pressure of the fuel on one side to the nozzle needle (42,82), which is opposite to the fuel injection opening (30,30a); A valve element (52, 52a), which is designed to be driven to either a high-pressure fuel passage (39, 39a), which includes the needle accommodating chamber (36) and the fuel passage (38, 38a), or a low-pressure Fuel passage (54) connected to the fuel tank (10) to connect to the pressure control chamber (46,46a), - an electric actuator (62,62a) configured to be energized around the valve element (52,52a); wherein fuel is injected through the high pressure fuel passage (39,39a) out of the fuel injection port (30,30a) when the nozzle needle (42,82) is driven by the energization of the electric actuator; and wherein the fuel passage (38, 38a) and the electrical actuator (62, 62a) are basically arranged parallel to one another and are arranged one behind the other in the fuel injection valve (24, 24a) in a direction perpendicular to a central axis of the fuel injection valve (24, 24a); and wherein the pressure control chamber (46, 46a) is arranged on a side of the electrical actuator (62, 62a) on which the fuel injection opening (30, 30a) is located in the direction of the central axis of the fuel injection valve (24, 24a). Fuel injection control device according to Claim 2 , characterized in that the correction device (S18, S20) is designed to increase the fuel injection quantity (Qt) when the fuel temperature (T _ij ) in the fuel injection valve (24, 24a) increases. Fuel injection control device according to at least one of Claims 1 to 3 characterized in that the fuel injection valve (24, 24a) includes: - a needle receiving chamber (36, 36a) formed by an inner wall of the fuel injection valve (24, 24a) and receiving the nozzle needle (42, 82); and - a fuel passage (38, 38a) connecting between the needle receiving chamber (36, 36a) and the fuel inlet (40, 40a); wherein the nozzle needle (42, 82) includes an enlarged portion (42b) disposed at an axially central portion of the nozzle needle (42, 82) and having an enlarged outer diameter opposite an adjacent portion of the nozzle needle (42, 82). which is adjacent to the enlarged portion (42b). Fuel injection control device according to Claim 4 Characterized in that the correction device (S18, S20) is adapted to increase the fuel injection quantity (Qt) when the fuel temperature (T _ij) falls in a low temperature range of the fuel temperature (T _ij) in the fuel injection valve (24,24a). Fuel injection control device according to at least one of Claims 1 to 5 , characterized in that the control device (64e) configured to control the fuel injection valve (24, 24a) to perform a plurality of fuel injections on a cylinder of the internal combustion engine per combustion cycle of the internal combustion engine; and further comprising fuel amount calculating means (64b) configured to calculate a required fuel injection amount required per combustion cycle of the internal combustion engine based on a required engine torque; and allocating means (64c) arranged to divide the required fuel injection amount and allocate each subset of the required fuel injection amount to a corresponding fuel injection of the plurality of fuel injections, wherein the correcting means (S18, S20) is adapted to each subset of required fuel injection amount, which is assigned to a corresponding fuel injection of the plurality of fuel injections, based on the fuel temperature (T _ij ) estimated by the temperature estimation means (S16). A method of controlling fuel injection in a fuel injection system of an internal combustion engine, wherein the fuel injection system used comprises an accumulator (18) adapted to accumulate fuel in a high pressure state, a fuel pump (14) adapted to supply fuel from a fuel tank (10) the accumulator (18) is formed, and includes a fuel injection valve (24,24a) adapted to receive the fuel accumulated in the accumulator (18) and having a fuel inlet (40,40a) and a nozzle needle (42,82), wherein the fuel inlet (40, 40a) receives the fuel supplied from the accumulator (18), and the nozzle needle (42, 82) is configured to open and close a fuel injection port (30, 30a) of the fuel injection valve (24, 24a), characterized in that a dwell period correspondence value (t _long ), which corresponds to a dwell time of the Kr A fuel in the fuel injection valve (24) since a time of entering the fuel injection valve (24) through the fuel inlet (40) is calculated based on ◦ a volume V of the high pressure fuel passage (39) from the fuel inlet (40) to an estimated position α; ◦ a fuel injection amount (Q _total ) to be injected from the fuel injection valve (24, 24a) per combustion cycle of the internal combustion engine ◦ an amount (Q _leak ) of a dynamic loss concerning the fuel discharged from the fuel injection valve (24) by a low pressure Fuel passage (54) is discharged to a fuel tank (10) due to the movement of the nozzle needle (42) at the time of fuel injection ◦ a period of time corresponding to a combustion cycle; and - wherein a fuel temperature (T _ij) is estimated in the fuel injection valve (24,24a) based on ◦ a difference between the temperature (T _body) of the fuel injection valve (24,24a) and a fuel temperature (T _in) of the fuel inlet (40, 40a) occurred fuel; and ◦ the dwell period correspondence value (t _long ) calculated by the dwell period calculating means (S12); and wherein an injection amount (Qt) of fuel to be injected from the fuel injection valve (24, 24a) is corrected based on the estimated fuel temperature (T _ij ); and - wherein a power supply of the fuel injection valve ( _24,24a ) is controlled based on a corrected fuel injection amount (Q _tfin ). Method for controlling the fuel injection after Claim 7 characterized in that the fuel injection valve (24, 24a) used includes: - a needle receiving chamber (36, 36a) formed through an inner wall of the fuel injection valve (24, 24a) and housing the nozzle needle (42, 82); a fuel passage (38, 38a) connecting between the needle receiving chamber (36, 36a) and the fuel inlet (40, 40a); - a pressure control chamber (46, 46a) which applies a pressure of the fuel on one side to the nozzle needle (42, 82) which is opposite to the fuel injection port (30, 30a); a valve element (52, 52a) driven to carry either a high pressure fuel passage (39, 39a) including a needle receiving chamber (36) and the fuel passage (38, 38a) or a low pressure fuel passage (54), which is connected to the fuel tank (10) to be connected to the pressure control chamber (46, 46a), - an electric actuator (62, 62a) which is energized to drive the valve element (52, 52a); wherein fuel is injected from the fuel injection port (30, 30a) through the high-pressure fuel passage (39, 39a) when the nozzle needle (42, 82) is driven by the energization of the electric actuator; and wherein the fuel passage (38, 38a) and the electric actuator (62, 62a) are basically arranged parallel to each other and arranged in a direction perpendicular to a central axis of the fuel injection valve (24, 24a) in the fuel injection valve (24, 24a) in series; and wherein the pressure control chamber (46, 46a) is disposed on a side of the electric actuator (62, 62a) on which the Fuel injection port (30,30a) in the direction of the central axis of the fuel injection valve (24,24a) is located. Fuel injection control method according to Claim 8 , characterized in that the fuel injection amount (Q _t ) is increased when the fuel temperature (T _ij ) in the fuel injection valve (24,24a) increases. Method for controlling the fuel injection after at least one of Claims 7 to 9 characterized in that the fuel injection valve (24, 24a) used includes: - a needle receiving chamber (36, 36a) formed through an inner wall of the fuel injection valve (24, 24a) and housing the nozzle needle (42, 82); and a fuel passage (38, 38a) communicating between the needle receiving chamber (36, 36a) and the fuel inlet (40, 40a); wherein the nozzle needle (42, 82) includes an enlarged portion (42b) disposed at an axially central portion of the nozzle needle (42, 82) and having an enlarged outer diameter opposite an adjacent portion of the nozzle needle (42, 82). which is adjacent to the enlarged portion (42b). Fuel injection control method according to Claim 10 Characterized in that the fuel injection amount (Q _t) is increased as the fuel temperature (T _ij) falls in a low temperature range of the fuel temperature (T _ij) in the fuel injection valve (24,24a). Method for controlling the fuel injection after at least one of Claims 7 to 11 characterized in that the fuel injection valve (24, 24a) is controlled to perform a plurality of fuel injections on a cylinder of the internal combustion engine per combustion cycle of the internal combustion engine; and further calculating a required fuel injection amount required per combustion cycle of the internal combustion engine based on a required engine torque; and the required fuel injection amount is divided, and each subset of the required fuel injection amount is assigned to a corresponding fuel injection of the plurality of fuel injections, wherein each subset corrects the required fuel injection amount assigned to a corresponding fuel injection of the plurality of fuel injections based on the fuel temperature (T _ij ) becomes.

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