JP2002070614A - Method and device for controlling fuel metering to internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for controlling fuel metering to an internal combustion engine. SOLUTION: A main injection starting signal representing a start of main injection can be set on the basis of at least one moment weight representing a demand from a driver. An amount representing fuel efficiency can be set on the basis of the main injection starting signal at least, and an overall fuel amount signal representing an overall fuel amount to be injected can be set on the basis of the amount representing the fuel efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and a device for controlling fuel metering for an internal combustion engine.

[0002]

BACKGROUND OF THE INVENTION Published German Patent Application No. 198
No. 6,398,398 discloses a method and a device for controlling fuel metering to an internal combustion engine. There, the fuel metering is divided into at least one first partial injection and a main injection. At that time, the drive start for the main injection is calculated, which is used for the drive only at the next next main injection. Therefore, when the start of driving of the main injection is determined, a time delay occurs from data detection to actual injection. The signal which determines the duration of the injection and thus the quantity of fuel to be injected is used each time for the next injection.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and a device for controlling fuel metering of an internal combustion engine.

[0004]

According to the present invention, a main injection start signal indicating the start of main injection can be set based on at least one moment amount indicating a driver's request, and at least a main injection start signal can be set based on the main injection start signal. The problem is solved by a method in which an amount representing the combustion efficiency can be set and a total fuel amount signal representing the total fuel amount to be injected can be set based on the amount representing the combustion efficiency. The object is also to set a main injection start signal indicating the start of main injection based on at least one moment amount indicating a driver request, to set an amount indicating combustion efficiency based on at least the main injection start signal, Is solved by constructing an apparatus provided with means for setting a total fuel amount signal representing the total fuel amount to be injected based on the amount representing.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention enables extremely accurate fuel metering, and in particular minimizes the time delay from the detection of data to the determination of a drive signal for fuel metering.

It is particularly advantageous that a first partial injection start signal, which indicates the start of a first partial injection, based on at least one total fuel quantity signal when a first interrupt occurs, and a first partial injection signal. And a first partial quantity signal representing the quantity of fuel injected into the fuel cell. Thus, the data for the pre-injection can be obtained based on the driving characteristic amount at the time when the pilot interrupt occurs immediately before the pre-injection.

[0007] More preferably, a second partial quantity signal representing the quantity of fuel injected during the third partial injection is based on the at least one total fuel quantity signal when the second interrupt signal is generated. Can be set. Thus, the data for the main injection can be obtained immediately before the injection, at the time of the occurrence of the main interrupt, based on the driving characteristic amount at that time.

[0008] It is particularly advantageous if the main injection start signal, the quantity representing the combustion efficiency and the total fuel quantity signal are based on the data present at the time of the first and second interrupts. It can be newly calculated.

According to the present invention, a phase shift is eliminated. All data about the injection can be calculated at each point in time.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail hereinafter with reference to an illustrated embodiment.

FIG. 1 shows the main elements of a system for controlling fuel metering of an internal combustion engine. The control device is indicated by reference numeral 100. This control device applies a drive signal A to the actuator 110. Furthermore, a pulse wheel (Impulsrad) 125 arranged on the crankshaft and / or the camshaft is provided, and is scanned by a sensor 120 connected to the control device 100. Further sensors 130, 140 are provided, which generate signals representing the operating state and the ambient conditions of the internal combustion engine.

The sensor 120 emits pulses, which occur at predetermined angular positions on the crankshaft and / or camshaft. Advantageously the pulse wheel 12
The markings on 5 are each arranged such that a pulse is generated at the top dead center of the cylinder of the internal combustion engine. In addition, an increment wheel is provided, delivering pulses at relatively small intervals of about 6 °. Another sensor 140
Sends out a signal M representing the driver's request. Here, this is preferably a signal representing the moment demand on the internal combustion engine. These quantities can also be adjusted by another control unit.

A further sensor 130 preferably emits a signal P representing the fuel pressure. In so-called common rail systems, this is advantageously rail pressure. Another drive characteristic amount and another ambient condition may be detected using a sensor (not shown).

The control device 100 calculates a drive signal A to be applied to the actuator 110 based on various drive characteristics and / or ambient conditions. On the basis of the driver's requirement or moment requirement M and the rotational speed N of the internal combustion engine, the control device 100 determines an amount that determines the amount of fuel to be injected. Further, an amount that determines the start of injection is determined based on various amounts, for example, the amount of fuel to be injected. In addition to the moment demand and speed, the driving condition of the vehicle and / or
Alternatively, other quantities representing the operating state of the internal combustion engine can be considered. The control device 100 calculates a drive signal A to be applied to the actuator 110 based on the amount indicating the start of injection and the amount of fuel to be injected.

The actuator 110 is preferably a solenoid valve or a so-called piezo actuator. Drive signal A
Depending on the position, the actuator 110 may take a position where injection is performed or a position where injection is not performed. Preferably, a signal for determining the drive start and a signal for determining the drive end are output.

Fuel metering in the cylinder combustion cycle is often divided into multiple partial injections. Advantageously 1
A small pre-injection and a large main injection are performed per combustion cycle. The main injection mainly produces a moment output from the internal combustion engine. Still another partial injection may be provided in addition to the pre-injection and the main injection. For example, another post-injection can be performed. Pre-injection, main injection, or post-injection are each performed multiple times before,
It can also be divided into main injection and / or post injection.

The method of the present invention will be described below with reference to embodiments of pre-injection and main injection. However, the technique of the present invention can be applied to other partial injections. The technique of the present invention is applicable when at least one first partial injection and second partial injection are performed. Hereinafter, the first partial injection is referred to as pre-injection, and the second partial injection is referred to as main injection.

The calculation of the drive signal for the injection is performed in two stages. The pre-injection data is calculated by a so-called pilot interrupt that occurs when the crank angle is about 120 ° ahead of the ignition top dead center, and the main interrupt is generated by a main interrupt that occurs when the crank angle is about 60 ° ahead of the ignition top dead center. Injection and post-injection are calculated. In the pilot interrupt, an angle that determines the start of main injection is calculated based on the required moment demand M and the rotation speed N. The angle that determines the start of the main injection is an amount that greatly affects the combustion efficiency on the combustion side. Therefore, an amount representing the combustion efficiency is obtained based on the angle and the rotation speed of the main injection. In this case, the total fuel quantity to be injected is calculated based on the quantity representing the combustion efficiency. Part of the fuel quantity is divided into a pre-injection and a subsequent main or post-injection taking into account the electrical and fluid limiting conditions. The start and quantity of the pre-injection are calculated for this. The corresponding calculations are shown in the flow chart of FIG.

In a first step 200, it is checked whether an interrupt signal IR1 is present. If not, step 200 is newly performed. The interrupt signal IR1 indicates a predetermined angular position of a crank angle at which data of pre-injection is calculated. This angular position is chosen so that the data is calculated at the appropriate time before the pre-injection. Normally, the trigger of the interrupt signal IR1 is performed at a position about 120 ° ahead of the top dead center.

If an interrupt signal IR1 occurs, a main injection start signal ABHE is calculated in a subsequent step 210. This signal indicates the drive start angle of the main injection.
The calculation of the main injection start signal is performed based on the moment demand M adjusted by the sensor 140. This is advantageously a quantity representing the driver demand. Moment demand M,
The calculation of the main injection start signal ABHE is performed on the basis of the rotational speed N and possibly other drive characteristic quantities. Preferably, a characteristic map is used for this. Subsequent step 220
Then, the quantity FMTC representing the efficiency of the injection depending on the start of the injection is determined. For this purpose, an additional additional quantity, which likewise represents the rotational speed of the internal combustion engine, is preferably taken into account.

Based on the efficiency and another drive characteristic not shown, the system calculates in step 230 a total fuel quantity signal representing the total fuel quantity to be injected.

In the next step 240, a first partial injection start signal indicating the start of the first partial injection and a partial amount signal indicating the amount of fuel injected in the first partial injection are set. Here, the hydraulic effect is taken into account, for example the rail pressure P and / or the rotational speed N.

In the main interrupt, the main injection angle is newly calculated once again. The reason is that the required moment M and / or speed may have changed between the pilot interrupt and the main interrupt. From this, the efficiency is also newly calculated, and the remaining fuel quantity corresponding to the total fuel quantity minus the pre-injection quantity is divided into main injection and post-injection. For this purpose, the time points and quantities for the main injection and the post-injection are calculated.

The corresponding measures are shown in a flow chart in FIG. In a query step 300, it is checked whether there is a second interrupt, called the main interrupt. If it does not exist, step 300 is newly added.
Is performed. If it is determined in the inquiry step 300 that a corresponding interrupt has occurred, a signal ABHE representing the drive start angle of the main injection is calculated in a step 310, corresponding to the step 210. In a corresponding step 320, an efficiency FMTC depending on the start of injection is determined as in step 220. In the following step 330, the fuel amount QK to be injected is calculated. Following step 340
The fuel quantity to be injected is divided into various partial injections.
In this case, in step 340, a partial quantity signal ADNE representing the quantity of fuel to be metered during the post-injection is determined. In the following step 350, a main injection amount signal indicating the amount of fuel injected at the time of the main injection is set. Subsequently, in step 360, a partial injection start signal ABNE indicating the third partial injection start, that is, the post-injection is set. Blocks 340, 350, 3
The calculation at 60 is preferably performed as a function of the speed and other variables, for example rail pressure. In particular, the drive duration signal is calculated as a function of the rail pressure. Blocks 340-360
May be performed in the sequence shown,
Also, it may be performed in any other sequence.

The accuracy of the calculation of the injection data can be significantly improved by means of the invention. In particular, the data of the main injection and the post-injection, that is, the data of the start of injection and the duration of the injection, can be calculated accurately. This is because the change in the rotational speed and the change in the moment demand between the pilot interrupt and the main interrupt are taken into account.

The partial injection data, in particular the main injection and the post-injection data, are based on the current data on the desired moment and the number of revolutions occurring.

[Brief description of the drawings]

FIG. 1 is a block diagram of a fuel metering control device.

FIG. 2 is a flowchart showing a first embodiment of the method of the present invention.

FIG. 3 is a flowchart showing a second embodiment of the method of the present invention.

[Explanation of symbols]

 Reference Signs List 100 control device 110 actuator 120, 130, 140 sensor 125 pulse wheel

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Rainer Jauudas Germany Korntal-Mün-Hingen Steinweisstraße 14 (72) Inventor Christoph Hammer Germany Stuttgart to Irastrasse 10 (72) Inventor Ud Schulz Germany Weichingen / Enz Kornblumenweg 34 (72) Inventor Michael Schuler Friolzheim Brühlstrasse 24 Germany F F-term (reference) 3G301 JA03 LB06 MA11 MA18 MA23 MA26 MA27 NA09 NC02 PA17Z PB08Z PE01Z PE03Z PE04Z

Claims (6)

[Claims] 1. A method for controlling fuel metering to an internal combustion engine, wherein the fuel metering can be divided into at least one first partial injection and a main injection, the method comprising the steps of: A main injection start signal indicating the start of the main injection can be set based on at least one main injection start signal; an amount indicating the combustion efficiency can be set based on at least one main injection start signal; A method for controlling fuel metering for an internal combustion engine, wherein a total fuel quantity signal representing a total fuel quantity to be set can be set. 2. A first partial injection start signal indicating the start of a first partial injection based on at least a total fuel amount signal when a first interrupt occurs, and injection is performed during the first partial injection. 2. The method according to claim 1, wherein a first partial quantity signal representative of the fuel quantity is configurable. 3. A second partial amount signal representing a fuel amount injected at the time of the third partial injection can be set based on at least the full fuel amount signal when the second interrupt signal is generated. The method according to claim 1. 4. A main injection amount signal representing an amount of fuel injected during main injection can be set based on at least a total fuel amount signal when a second interrupt signal is generated. The method according to any one of the preceding claims. 5. A second partial injection start signal indicating the start of a third partial injection can be set based on at least the total fuel amount signal when the second interrupt signal is generated. The method according to any one of the preceding claims. 6. A device for controlling fuel metering to an internal combustion engine, wherein the fuel metering can be divided into at least one first partial injection and a main injection, wherein at least one moment quantity representing a driver demand is provided. Setting a main injection start signal indicating the start of the main injection based on
Means for setting an amount indicating combustion efficiency based on at least the main injection start signal, and setting a total fuel amount signal indicating total fuel amount to be injected based on the amount indicating combustion efficiency. A device for controlling fuel metering for an internal combustion engine.