DE102008054729A1 - Method for starting internal combustion engine, particularly for driving motor vehicle, involves turning crankshaft immediately after turning-off internal combustion engine by using starter - Google Patents

Abstract

The method involves turning a crankshaft (24) immediately after turning-off an internal combustion engine (10) by using a starter to locate a reference mark of a pickup wheel in the proximity of a sensor element. The position of the stationary crankshaft is determined after turning-off the internal combustion engine.

Description

The The invention relates to a method for starting an internal combustion engine According to the preamble of claim 1. In addition, a Control and / or regulating device and an internal combustion engine according to the preamble of the corresponding independent claims Subject of the invention.

State of the art

increasing Fuel prices, increasingly stringent emission limits and the objective of to further reduce carbon dioxide emissions innovative solutions. So is, for example, an electronically controlled Stop / start system known where the engine is at vehicle standstill automatically shut off. As soon as the driver wants to start again For example, by pressing the clutch pedal, the internal combustion engine automatically started. By such a system can, for example, the fuel consumption and the carbon dioxide emission during a city trip according to standardized measurements of the New European Driving cycle (NEDC) can be reduced by up to eight percent. To the necessary acceptance by customers for such a system Achieving is the realization of a fast startup process absolutely necessary.

The DE 199 63 516 A1 shows an internal combustion engine with the electrical energy is obtained by a rotation of the crankshaft and the electrical energy is used to support the startup operation with a separate drive motor for a short time. For this purpose, the corresponding positions of the crankshaft and the camshaft are detected by means of a crankshaft and a camshaft position sensor and the supply of electrical energy to the drive motor is controlled by a control unit. The internal combustion engine can thereby start efficiently in a short time. This method can only be carried out when the internal combustion engine and with it the control unit are in operation.

at The so-called direct start fuel is directly into a combustion chamber the internal combustion engine sprayed and ignited. It will a cylinder is selected in which the cylinder at the time of Ignition has a suitable position to start. The advantage of the direct start is that the start time is reduced. The starter-assisted direct start is the direct start supported with the already existing starter / starter and thereby further reduces the start time.

Around to perform a direct start, must the selected cylinder in a well-defined and appropriate position. For this purpose, a rotation angle sensor used, the sender wheel is firmly connected to the crankshaft. The sender wheel has a variety of teeth one Reference mark on. With the help of the teeth and the reference mark the encoder wheel, the rotation angle sensor, the position of the crankshaft determine. The control and / or regulating device of the internal combustion engine sets the output signal of the rotation angle sensor to the controller and Control of the internal combustion engine. Since the output signal of the rotation angle sensor is not stored permanently in the control unit, goes the Position of the crankshaft "lost" as soon as that Control unit is de-energized. After the renewed Switching on the control unit requires the reference mark of the encoder wheel once passed the angle of rotation sensor to the position to determine the crankshaft. Subsequently has the control and / or regulating device as long as over the current crankshaft angle, as long as it is energized.

The Control and / or regulating device of an internal combustion engine Motor vehicle, however, is energized only as long as the ignition key plugged into an ignition lock or the control and / or control device after removing the ignition key in a lag time. This is, for example, a follow-up start during stop / start operation, given the ignition key at Stop / start operation remains in the ignition. But you are remove the car and remove the ignition key, then are the output signal at the end of the controller overrun time of the rotation angle sensor and with it the crankshaft position deleted and stand for a later start - the so-called First start - the internal combustion engine is no longer available.

Disclosure of the invention

task The invention is to develop a method of the type mentioned, in which the internal combustion engine especially at the first start, d. H. if the controller only immediately before starting the internal combustion engine was supplied with electrical energy, reliable and starts fast.

These The object is achieved by a method having the features of the claim 1 solved, as well as by a control and / or regulating device and an internal combustion engine with the characteristics of the siblings Claims. Features important to the invention can also be found in the following description and in the Drawing, with the characteristics both alone and important in different combinations for the invention can be, without explicit reference becomes. Advantageous developments can be found in the subclaims.

The inventive method for starting the internal combustion engine is for a starter-assisted direct start designed to realize fast start times.

Of the Invention is based on the idea, immediately after switching off the internal combustion engine and during the follow-up time the control and / or regulating device preparations for the later initial start of the engine too meet and thereby a first start as a starter-assisted Enable direct start. This is inventively characterized realized that after switching off the internal combustion engine the Crankshaft is positioned so that the necessary position detection the crankshaft can be done very quickly and a short after first start as a direct start with starter support carried out can be. This means that when using the inventive Procedure the start time at first start not from that of a next start in stop / start operation is different.

To this purpose is proposed according to the invention, that after switching off the internal combustion engine, preferably after removing the ignition key and while of the ECU tracking, determines the position of the stationary crankshaft is that a rotation angle α between the reference mark of Sensor wheel and the sensor element of a rotation angle sensor determined is, and then that the crankshaft rotated by an angle φ is smaller than the rotation angle α between the next Reference mark and the sensor element is. The reference mark defines a basis for the rotation angle calculation. Therefore, the zero point (0 °) the angle of rotation often with the reference mark of the encoder wheel equated.

By the sequence described above is advantageously during the lag time the crankshaft is positioned so that the Reference mark of the encoder wheel in the immediate vicinity of the sensor element of the rotation angle sensor is located, so that in the subsequent First start a short start to detect the position of the crankshaft needed for the first start. So the goal is Position the crankshaft so that the angle between the Reference mark of the encoder wheel and the rotation angle sensor is reduced. This may, for example, during a follow-up period of the control and / or regulating device happen, wherein moving the crankshaft happens through the starter.

A simple realization of the determination of the starting position for the first start is possible if the angle φ, by which the crankshaft is rotated, is equal to the product of a factor A and the determined angle of rotation α, and that the factor A is less than 1 (A <1 ), preferably equal to 0.5. This means that in any case the new position of the crankshaft is closer to the following reference mark. The angle of rotation φ of the crankshaft can be determined according to the following equation: Angle φ = determined angle of rotation α · A

Example:

• A = 0.5
• Rest position of crankshaft: 40 °
• Determined angle of rotation α: 360 ° - 40 ° = 320 °
• Angle φ = 320 ° · 0.5 = 160 °

This means that in this example the crankshaft starting from its rest position is rotated by 160 ° at 40 °, do that at 200 ° and thus only 160 ° before the reference mark of the sender wheel is located. The angle around the crankshaft must be rotated before the reference mark of the encoder wheel passes over the sensor element is therefore relatively small (about 160 °), so the resulting noise by the user of the motor vehicle not at all or at least not as be perceived disturbing. In addition, the The algorithm described above is very simple and can easily be used in the control and / or regulating device can be implemented.

φ:

Winkel um den die Kurbelwelle gedreht wird

α:

ermittelter Drehwinkel

β:

vorgegebener Mindestwinkel

An alternative determination of the starting position for the first start is possible if the angle φ, by which the crankshaft is rotated, is equal to the determined rotational angle α minus a predetermined minimum angle β, and that the minimum angle β is preferably 30 °. The angle φ can be determined according to the following equation: φ = determined angle of rotation α - minimum angle β With:

φ:

Angle around which the crankshaft is rotated

α:

determined angle of rotation

β:

specified minimum angle

In further advantageous embodiment of the invention is provided that the crankshaft is not rotated when the rest position of Crankshaft after switching off the internal combustion engine within a predetermined angular range is. This angle range is so dimensioned that an additional positioning of the crankshaft is superfluous.

Before starting the internal combustion engine in previously de-energized control and / or regulating device, the crankshaft of the determined parking position is further rotated by the starter until the reference mark has reached the sensor element and exceeded. The trigger for this can, for example, a Öff NEN and then closing a driver's door, which can be determined by means of a sensor. Since the control and / or regulating device knows the crankshaft position at this point in time, the prerequisites for a subsequent first start as a starter-assisted direct start are met and a triggering of angle-synchronous interrupts (synchronization) via the encoder wheel for the sequence of the direct start is possible.

Brief description of the figures

following is an embodiment of the invention with reference to the figures exemplified. Show it:

1 a schematic representation of an internal combustion engine;

2 a schematic representation of the rotation angle sensor in cooperation with an exemplary cylinder piston 1 ;

3 a temporal scenario for two crankshaft revolutions in a six-cylinder internal combustion engine; and

4 a flow diagram of the method according to the invention.

Detailed description

An internal combustion engine carries in 1 Overall, the reference number 10 , It includes a tank 12 from which a conveyor system 14 Fuel in a common rail 16 promotes. At this are several injectors 18 connected, the fuel directly into them associated combustion chambers 20 inject. Every combustion chamber 20 includes a cylinder piston 22 , All cylinder pistons 22 are with a crankshaft 24 connected. At the crankshaft 24 is rotatably a rotation angle sensor 26 attached, over which a rotational position of the crankshaft 24 can be determined. The operation of the internal combustion engine 10 is controlled by a control device 28 controlled or regulated.

2 shows a schematic representation of the rotation angle sensor 26 in cooperation with a piston 22 out 1 , The rotation angle sensor 26 includes a donor wheel 30 that with a variety of teeth 32 is surrounded radially in each case with an ascending and a descending tooth flank. The donor wheel 30 is non-rotatable on the crankshaft 24 (not visible) attached and rotates with the crankshaft 24 , The teeth 32 are interrupted in a small peripheral area, leaving a gap 34 arises. The sender wheel points relative to the gap 34 a reference mark 38 on. The reference mark 38 For example, there may be two tooth flanks behind the gap 34 (in the direction of rotation 36 ) and allows the position detection of the crankshaft 24 , The reference mark 38 is from a (rotation angle) sensor 40 identified. In addition, the sensor can 40 by interpreting the flanks of the teeth 32 a rotational position (rotational angle) of the crankshaft 24 identify. The sensor 40 has an electrical connection to the control and regulating device 28 , In the illustrated embodiment allow the teeth 32 a determination of the angle of rotation of the crankshaft with a resolution of 6 °. By changing the teeth 32 The tolerance range of the rotation angle can be changed accordingly.

3 shows the development for two crankshaft revolutions in a 6-cylinder internal combustion engine. In the upper area of 3 is a scale with the corresponding degrees at two crankshaft revolutions, ie from 0 ° to 720 °, indicated. Underneath is the processing of the teeth 32 shown. By vertical lines 42 are in 3 the so-called ZOTs in the six combustion chambers 20 shown. The abbreviation ZOT stands for ignition upper dead center. This refers to the top dead center between the work cycles "compression" and "expansion".

Two teeth behind the gap 34 (in the direction of rotation) is the reference mark 38 , The reference mark 38 represents the base (0 °) for the angle measurement.

By way of example, an embodiment of the method according to the invention is explained (see 3 and 4 ). The starting point is a switched-off internal combustion engine in the follow-up time of the control and regulating device 28 , The crankshaft 24 is in a resting position 44 ,

During the follow-up time determined in step 100 the rotation angle sensor 40 the resting position 44 the crankshaft 24 and sends this information to the control and regulating device 28 , Between the resting position 44 and the position of the next fiducial 34a can now in step 110 an angular distance α to the next reference mark 34a (= 360 °) can be determined. The angle α is then multiplied by a predetermined factor A (step 120 ). The result is the angle φ by which the crankshaft is rotated. So the following formula applies: Angle φ = determined angle of rotation α · A

Example:

• A = 0.5
• Rest position of crankshaft: 40 °
• Determined angle of rotation α: 360 ° - 40 ° = 320 °
• Angle φ = 320 ° · 0.5 = 160 °

On the thus determined angular position φ, which is a parking position 46 the crankshaft 24 for a next start corresponds, in step 130 the crankshaft 24 now positioned. The wake of the control and regulating device 28 will be terminated; all stored information is deleted. A subsequent start (first start) can not rely on existing information on the position of the crankshaft.

However, the crankshaft 24 According to the invention positioned so that a known method for starter-assisted direct start of the internal combustion engine can be performed as a first start. The start time is very short, because the reference mark 38 the donor wheel 30 Immediately after the starter is actuated, the sensor 40 passes over and thereby the position of the crankshaft 24 becomes known.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19963516 A1 [0003]

Claims (9)

Method for starting an internal combustion engine ( 10 ), preferably in a motor vehicle, with a starter, a rotation angle sensor ( 26 ) comprising a fixed sensor element ( 40 ) and a rotationally fixed with a crankshaft ( 24 ) of the internal combustion engine ( 10 ) connected encoder wheel ( 30 ), whereby the encoder wheel ( 30 ) at least one reference mark ( 38 ), characterized in that the crankshaft ( 24 ) immediately after a shutdown of the internal combustion engine ( 10 ) is rotated so far by means of a starter until the reference mark ( 38 ) of the encoder wheel ( 30 ) in the vicinity of the sensor element ( 40 ) is located. A method according to claim 1, characterized in that after switching off the internal combustion engine ( 10 ) the position of the stationary crankshaft ( 24 ) is determined that a rotation angle α between the reference mark ( 38 ) and the sensor element ( 40 ), and then the crankshaft ( 24 ) is rotated by an angle φ which is smaller than the rotation angle α. Method according to claim 1 or 2, characterized in that the angle φ about which the crankshaft ( 24 ) is equal to the product of a factor (A) and the determined angle of rotation α, and that the factor (A) is less than 1 (A <1), preferably equal to 0.5. Method according to claim 1 or 2, characterized in that the angle φ about the crankshaft ( 24 ) is equal to the determined angle of rotation α minus a predetermined minimum angle β, and that the minimum angle β is preferably 30 °. Method according to one of the preceding claims, characterized in that the crankshaft ( 24 ) during a follow-up period of a control and / or regulating device ( 28 ) is rotated. Method according to one of the preceding claims, characterized in that the crankshaft ( 24 ) is not rotated when the current position of the crankshaft ( 24 ) is within a predetermined angular range after switching off. Method according to one of the preceding claims, characterized in that before starting the internal combustion engine ( 10 ) the control and / or regulating device ( 28 ) is energized, and that the crankshaft ( 24 ) is rotated by the starter so far that the reference mark ( 38 ) the sensor element ( 40 ) reaches or passes over. Control and / or regulating device ( 28 ) for an internal combustion engine ( 10 ), characterized in that it is programmed for use in a method according to one of the preceding claims. Internal combustion engine ( 10 ), in particular for driving a motor vehicle, with a starter, a rotation angle sensor ( 26 ) comprising a fixed sensor element ( 40 ) and a rotationally fixed with a crankshaft ( 24 ) of the internal combustion engine ( 10 ) connected encoder wheel ( 30 ), and a control and / or regulating device ( 28 ), characterized in that the control and / or regulating device ( 28 ) is programmed for use in a method according to one of claims 1 to 7.