EP1845250A1 - Initial learning process - Google Patents

Abstract

The method involves pressurizing selected start-up cylinder with predetermined amount of air so that predetermined crank angle rotates reciprocating-motion piston combustion engine. Another start-up cylinder is selected, when reciprocating-motion piston combustion engine does not rotate. The absolute crank angle of reciprocating-motion piston is determined from reference mark indicated by detector after pressurizing the newly selected start-up cylinder. Independent claims are included for the following: (1) crank-angle sensor unit; and (2) reciprocating-motion piston engine.

Description

The invention relates to starting learning method for determining a crank angle of a reciprocating internal combustion engine, a crank angle sensor unit for determining a crank angle, and a reciprocating internal combustion engine according to the preamble of the independent claim of the respective category.

Large diesel engines are often used as drive units for ships, but also in stationary operation, e.g. used to drive large generators for generating electrical energy. The engines usually run for long periods in continuous operation, which places high demands on the reliability and availability.

Starting such engines with starting air, because of the enormous size of the machines start by means of an electric drive unit, as it is known for example from car or truck engines or smaller marine engines, is out of the question.

In order to reliably start the machine in a certain direction of rotation, usually two or more cylinders in a row must successively In this order, which is essentially determined by the firing sequence used during normal operation of the machine, be supplied with starting air until the machine starts to run of its own accord. So that the correct order can be found, with which the cylinders of the internal combustion engine must be acted upon for starting with starting air, the absolute crank angle of the stationary machine must be known before the initiation of the start sequence, otherwise it can not be determined in which order which cylinder the Internal combustion engine are to be acted upon with starting air. If one realizes that very large diesel engines today can already have up to 14 cylinders, there is in principle an incalculable number of possibilities to apply two or more cylinders to start the engine with starting air.

It is therefore clear that in general the machine can be reliably started only with a reasonable effort, if previously the absolute crank angle of the machine is known at a standstill, so that the correct start sequence can be found from the knowledge of the absolute crank angle.

Under normal circumstances, this does not present a major problem today, since the modern machines have an electronic drive unit with data processing system in which the last crank angle can be stored at the last standstill of the machine, so that the machine's absolute crank angle is restored at a subsequent start Available.

However, there are special situations in which the value of the absolute crank angle is lost, or no longer coincides with the last stored value.

This can be the case, for example, if the ship's power supply to a ship fails completely due to a defect during a short drive, the machine comes to a standstill and the absolute crank angle can no longer be stored at standstill.

However, a much more relevant situation arises during maintenance work. In the case of certain maintenance work, it may be e.g. For safety reasons, it is necessary to completely disconnect the machine from the electrical power supply, ie to completely de-energize it. Of course, in this case, too, the absolute crank angle of the machine can be stored in advance. However, depending on the nature of the maintenance work, the machine must e.g. be rotated by a certain, undefinable crank angle, which is e.g. can be done by external electric drive, so that at the end of the work, the value of the absolute crank angle of the internal combustion engine is unknown.

Thus, in such a case, the machine can be restarted, devices are known in the known from the prior art devices provided with which the absolute crank angle of the engine can be determined even at a standstill.

For clarity, an internal combustion engine with such a known device is shown schematically in Fig. 1. In order to distinguish the prior art from the present invention, the reference numerals of FIG. 1 have been provided with an apostrophe.

In Fig. 1, a known large diesel engine is shown schematically, for example, can have up to 12, 13 or 14 cylinders, or even more, and the housing in a conventional manner a stator 8 'and a crankcase 9' comprises, in which crankcase 9 ', the crankshaft 3' is mounted. Outside the actual motor housing, an angle measuring device 10 'is provided with which the absolute crank angle 7' of the reciprocating internal combustion engine 2 'can be determined at any time. The angle measuring device 10 'comprises a drive pulley 31', which is on the one hand rotatably and angularly coupled to the crankshaft 3 'and on the other hand via a drive belt 32' with a measuring disk 4 'rotatably coupled, wherein on the measuring disk 4' reference marks 5 'are provided so that the absolute crank angle 7 'can be read out or read either electronically or by visual inspection.

Although often the crank angle 7 'determinable by the angle measuring device 10' is also used for other purposes besides starting the machine, e.g. for measuring crank angles in the operating state, the angle measuring device 10 ', except for starting the engine after a loss of the value of the absolute crank angle 7', in principle superfluous because in the operating state, the current crank angle 7 'of the internal combustion engine in the conventional manner also can be procured differently. During normal operating conditions of the engine 2 ', the angle measuring device 10' is therefore only used to determine the crank angle 7 ', since the angle measuring device 10' previously had to be mandatory to start the machine 2 'after loss of the absolute crank angle 7' can.

For obvious reasons, it should be understood that it would thus be beneficial to dispense entirely with an additional goniometer if another means of starting the engine could be provided after loss of the absolute crank angle. As a result, not only the costs for providing the angle measuring device as such could be saved. Also, appropriate repairs and maintenance can be omitted and ultimately the reliability can be increased because of a defect or failure of the known angle measuring the absolute crank angle of the machine can now be determined without enormous effort.

The object of the invention is therefore to provide a method and a device, so that a simple crank angle of a reciprocating internal combustion engine can be determined in a simple manner.

The objects of the invention which solve these objects in terms of process and apparatus are characterized by the features of the independent claim of the respective category.

The respective dependent claims relate to particularly advantageous embodiments of the invention.

1. a.) Wahl eines Startzylinders; b.) Beaufschlagung des Startzylinders mit einer vorgegebenen Menge an Startluft; c.) im Fall, dass die Hubkolbenbrennkraftmaschine nicht in Drehung versetzt wird, wird ein anderer Startzylinder gewählt und das Startlernverfahren mit Schritt b.) fortgesetzt; d.) die Hubkolbenbrennkraftmaschine wird durch die Beaufschlagung des Startzylinders mit der Startluft um einen vorgegebenen Kurbelwinkel gedreht; e.) im Fall, dass die Hubkolbenbrennkraftmaschine in eine unerwünschte Richtung dreht, wird ein anderer Startzylinder gewählt und das Startlernverfahren mit Schritt b.) fortgesetzt; f.) im Fall, dass das Detektionsmittel die Referenzmarke nicht registriert, wird ein nächster Zylinder gewählt und das Startlernverfahren mit Schritt b.) fortgesetzt und im abschliessenden Schritt g.) registriert das Detektionsmittel die Referenzmarke, woraus ein absoluter Kurbelwinkel der Hubkolbenbrennkraftmaschine ermittelt wird.

The invention thus relates to a starting learning method for determining a crank angle of a reciprocating internal combustion engine, in particular a two-stroke large diesel engine, wherein a standing with a crankshaft of the reciprocating internal combustion engine in a rotationally effective operative connection reference means is provided with a reference mark, with which by interaction with a detection means an absolute crank angle of the reciprocating internal combustion engine can be defined. The starter learning process comprises the following steps:

1. a.) Choice of a starting cylinder; b.) admission of the starting cylinder with a predetermined amount of starting air; c.) in the event that the reciprocating internal combustion engine is not rotated, another starting cylinder is selected and the start learning process continues with step b.); d.) the reciprocating internal combustion engine is rotated by the application of the starting cylinder with the starting air by a predetermined crank angle; e.) in the event that the reciprocating internal combustion engine rotates in an undesired direction, another starting cylinder is selected and the start learning process continues with step b.); f.) In the event that the detection means does not register the reference mark, a next cylinder is selected and the start learning process continues with step b.) and in the concluding step g.) the detection means registers the reference mark, from which an absolute crank angle of the reciprocating internal combustion engine is determined.

The fact that the reference means is in operative connection with the crankshaft in terms of rotation angle means in the context of this application that a corresponding crank angle of the crankshaft can always be determined unambiguously from a rotation angle of the reference means.

By using the method according to the invention, it is thus possible for the first time to restart a two-stroke large diesel engine without any problems, even if the engine was completely de-energized and the crankshaft of the engine is rotated to an unknown crank angle when de-energized, for example during repair or maintenance work has been. That is, the inventive method allows for the first time, a two-stroke large diesel engine, but in principle also any other reciprocating internal combustion engine to restart without a device would be necessary, with the engine at a standstill first the absolute crank angle must be measured before the engine can be started.

In a preferred embodiment of a starter learning method according to the invention, the reference means is a gear rotatably connected to the crankshaft, which is often referred to as a "gear wheel" and in particular a drive gear for driving a motor assembly of the reciprocating internal combustion engine. Such a gear, which is preferably arranged in the crankcase within the engine at one end of the crankshaft, must be worked very precisely, so that the absolute or a relative crank angle with a precision of better than 3 angular degrees, in particular more precisely than 1 angle degree, in particular at least with an accuracy of 0.1 angular degree of a crank angle or more accurately can be determined.

Preferably, but not necessarily, more than one reference mark, in particular two reference marks are provided on the reference means, or in particular the number of reference marks is equal to the number of cylinders of the reciprocating internal combustion engine, or the number of reference marks is greater or smaller than the number of cylinders the reciprocating internal combustion engine.

In specific embodiments, more than one detection means, in particular two detection means may be provided for detecting the reference mark, or in particular the number of detection means may be equal to the number of cylinders of the reciprocating internal combustion engine, or the number of detection means is greater or smaller than the number of cylinders the reciprocating internal combustion engine.

Embodiments with more than one detection means and / or more than one reference means are particularly suitable for simply detecting not only the rotation angle but also the direction of rotation of the reciprocating internal combustion engine and / or to ensure a higher angular resolution. whereby, for example, the number of possible unsuccessful attempts when carrying out the method according to the invention can be significantly reduced, and in particular starting air is saved.

In this case, the reference mark may be an optical reference mark, e.g. a mark and / or a magnetic reference mark, e.g. a magnetic element that may be disposed in or on the gear or the gear may have a magnetic signature imprinted on it, and / or the reference mark may be an electrical reference mark and / or an electromagnetic reference mark, e.g. in the form of a transponder and / or a capacitive reference mark and / or an inductive reference mark and / or another reference mark and / or the detection means may comprise an optical detection means, e.g. a photocell, a photodiode or a phototransistor and / or the detection means is a magnetic detection means and / or an electrical detection means and / or an electromagnetic detection means, e.g. a receiver or a transponder and / or a capacitive detection means and / or an inductive detection means and / or another detection means.

That is, the reference mark can be any suitable means that can be advantageously used as a reference mark for indexing a crank angle and the detection means can be any suitable sensor that is suitable to detect the reference mark.

The invention further relates to a crank angle sensor unit for determining a crank angle of a reciprocating internal combustion engine, comprising a standing with the crankshaft of the reciprocating internal combustion engine in a rotationally effective operative connection reference means with a reference mark, and a detection means with which an absolute crank angle of the reciprocating internal combustion engine can be defined by interaction with the reference mark wherein the reference means is provided within the reciprocating internal combustion engine, in particular within the stator and / or the crankcase of the reciprocating internal combustion engine.

In this case, the reference means is preferably a non-rotatably connected to the crankshaft gear, in particular a drive gear for driving a motor assembly. The particular advantage of using such a gear, which is often referred to as a "gear wheel" and mounted at the end of the crankshaft actually for driving various units of the engine, such as. used by pumps, is that the very expensive from the state of the art, outside the engine arranged measuring device with timing belt, angle sensor and detection sensor can be omitted and instead the existing anyway in the engine gear, especially the "Gear Wheel" is used.

It goes without saying that this represents a considerable simplification, reduces maintenance and of course much more cost-effective than the use of an additional measuring device outside the engine, which is except for determining the absolute crank angle of the engine for determining a relative crank angle and usable is also used, but is superfluous by the use of the inventive solution, since the relative crank angle can be obtained in a conventional manner in the operating state of the internal combustion engine in other ways. In particular, the relative crank angle in the normal operating state can of course also be detected with a device according to the present invention.

In a specific embodiment of a crank angle sensor unit according to the invention, more than one reference mark is provided on the reference means, in particular two reference marks are provided, or in particular the number of reference marks is equal to the number of cylinders of the reciprocating internal combustion engine, or the number of reference marks is greater or less than that Number of cylinders of reciprocating internal combustion engine.

In another embodiment, more than one detection means for detecting the reference mark, in particular two detection means are provided, or in particular the number of detection means is equal to the number of cylinders of the reciprocating internal combustion engine, or the number Detection means is larger or smaller than the number of cylinders of the reciprocating internal combustion engine.

The reference mark may be an optical reference mark and / or a magnetic reference mark and / or an electrical reference mark and / or an electromagnetic reference mark and / or a capacitive reference mark and / or an inductive reference mark and / or another reference mark and / or the detection means is a optical detection means and / or a magnetic detection means and / or an electrical detection means and / or an electromagnetic detection means and / or a capacitive detection means and / or an inductive detection means and / or another detection means. The suitable detection means or suitable reference marks are known per se to those skilled in the art and some have already been listed above.

The invention also relates to a reciprocating internal combustion engine having a crank angle sensor unit as described in detail above for carrying out a starter learning method according to the present invention.

Fig. 1

eine bekannte Hubkolbenbrennkraftmaschine mit Absolutwinkelmesser;

Fig. 2

ein schematischer Ablaufplan eines erfindungsgemässen Startlernverfahrens;

Fig. 3

eine erfindungsgemässe Hubkolbenbrennkraftmaschine mit Kurbelwinkel-Sensoreinheit.

In the following the invention will be explained in more detail with reference to the schematic drawing. Show it:

Fig. 1

a known reciprocating internal combustion engine with absolute angle;

Fig. 2

a schematic flowchart of an inventive starter learning method;

Fig. 3

an inventive reciprocating internal combustion engine with crank angle sensor unit.

To distinguish the prior art of the embodiments of the present invention, as already mentioned, those features that are provided on a known reciprocating internal combustion engine with a single decimal, while the features of inventive devices do not carry apostrophes.

Fig. 1 shows a schematic representation of an embodiment of an angle encoder, as it has long been known from the prior art. Since this example has already been discussed in detail at the beginning, a further description of FIG. 1 is unnecessary here.

In FIG. 2, the general sequence of the method according to the invention, which is referred to in the following as the entirety by the reference numeral 1, is shown schematically in the form of a flow chart.

First, a starting cylinder is selected. The choice may coincidentally fall on any cylinder of the reciprocating internal combustion engine 2 according to FIG. 3, or, if there is certain information that a particular cylinder or group of cylinders may appear particularly suitable, e.g. It can be assumed that, upon application of this particular cylinder or cylinder of a particular group of cylinders, the engine 2 rotates in the desired direction, it selectively selects a particular cylinder or cylinder from the particular group of cylinders.

After the first selected starting cylinder has been subjected to starting air, it is determined by means of suitable sensors, which are provided on the internal combustion engine 2 in a conventional manner, whether the engine 2 has ever been rotated. If the engine does not turn 2, must after the aforementioned criteria, ie either random or targeted another Starting cylinder can be selected, which has not previously been selected and is then acted upon again with starting air.

This is repeated until the engine 2 rotates.

When the motor 2 is rotated by the action of a starting cylinder, it is checked by means of the aforementioned sensors, or in particular also by means of further sensors, whether the motor 2 rotates in the desired direction. What is the desired direction may depend inter alia on whether a ship equipped with such a motor 2, e.g. forward or backward drive to record or be determined by other boundary conditions.

If the reciprocating internal combustion engine 2 is not rotating in the correct direction, another starting cylinder must be selected according to the criteria mentioned above, which has not yet been selected.

This is repeated until the motor 2 rotates in the desired direction.

Since the engine 2, when only a starting cylinder is charged with starting air, normally initially only rotates at a certain crank angle 7, it must be determined whether the reference mark 5 has been registered by the detection means 6 in the desired direction during the aforementioned rotation of the motor 2, ie, it has to be checked whether the motor 2 has turned so far that the reference mark 5 has been guided past the detection means 6, so that it could be detected by the detection means 6, thus for example by an optical sensor 6, so that the absolute crank angle 7 can be determined. It goes without saying that, of course, the absolute crank angle 7 can only be determined if the reference mark 5 can be detected at least once by the detection means 6.

In the event that the motor 2 has indeed rotated in the desired direction, but the rotated crank angle 7 was not sufficient to pass the reference mark 5 on the detection means 6, the motor 2 must be further rotated in the same direction. For this purpose, a next cylinder must be selected, which is either chosen randomly, or is expected from the information available that he continues to turn the machine 2 in the right direction by applying starting air.

The above-described procedure is repeated until the machine 2 passes by rotation in the correct direction, the reference mark 5 on the detection means 6, so that the absolute crank angle 7 of the reciprocating internal combustion engine 2 can be determined.

Once an absolute crank angle 7 has been found by detecting the reference mark 5 as a reference point, this can be detected e.g. stored in a memory of an electronic data processing system of the machine control and are determined by known per se incrementing for all subsequent operating conditions of the crank angle 7 of the machine 2. That is, after finding an absolute crank angle θ as a reference point by the starter learning method 1 according to the present invention, the engine 2 can be safely and reliably started in any desired rotational direction.

Finally, in FIG. 3, partially and in section, an inventive reciprocating internal combustion engine 2 with a crank angle sensor unit 10 according to the present invention is shown schematically.

The reciprocating internal combustion engine 2 comprises a standing with the crankshaft 3 in a rotationally effective operative connection reference means 4, which in the present example is a gear 4, which is present anyway in the machine 2, since it is for driving certain in Fig. 3, not shown drive units, such as Pumps or other aggregates is needed.

The gear 4 is equipped with a reference mark 5, wherein preferably at least 2 reference marks 4, which may be arranged in particular at an angular distance of 180 ° to the gear 4, are present. Furthermore, a detection means 6, which may be an optical sensor 6, for example, is provided, with which an absolute crank angle 7 of the reciprocating internal combustion engine 2 can be defined by interaction with the reference mark 5. The crank angle sensor unit 10 with reference means 4 and detection means 6 is, unlike the known from the prior art solutions, within the reciprocating internal combustion engine 2, insbesondre provided within the stator 8 and / or the crankcase 9 of the reciprocating internal combustion engine 2.

It is understood that the invention is not limited to the exemplary embodiments described above by way of example, but relates in particular, but not only, to all suitable combinations of the specific embodiments described.

Thus, not only a significantly improved method for starting a reciprocating internal combustion engine is proposed by the present invention, in which due to certain events, the current crank angle is not known before starting. In addition, a new crank angle sensor unit is provided, which essentially uses existing components of the reciprocating internal combustion engine with certain modifications, so that it is possible to completely dispense with the additional devices known from the prior art for determining the absolute crank angle of the reciprocating internal combustion engine.

Claims (11)

Start learning method for determining a crank angle of a reciprocating internal combustion engine (2), in particular with a crankshaft (3) of the reciprocating internal combustion engine (2) in a rotationally effective operative connection standing reference means (4) with a reference mark (5) is provided with which by interaction with a detection means (6), an absolute crank angle (7) of the reciprocating internal combustion engine (2) can be defined, the starter learning method (1) comprising the following steps: a.) Choice of a starting cylinder; b.) admission of the starting cylinder with a predetermined amount of starting air; c.) in the event that the reciprocating internal combustion engine (2) is not rotated, another starting cylinder is selected and the starting learning process (1) continues with step b.); d.) the reciprocating internal combustion engine (2) is rotated by the application of the starting cylinder with the starting air by a predetermined crank angle; e.) in the event that the reciprocating internal combustion engine (2) rotates in an undesired direction, another starting cylinder is selected and the starting learning process (1) continues with step b.); f.) in the event that the detection means (6) does not register the reference mark (5), a next cylinder is selected and the start learning process (1) continues with step b.); g.) the detection means (6) registers the reference mark (5), from which an absolute crank angle (7) of the reciprocating internal combustion engine (2) is determined becomes. Start learning method according to claim 1, wherein the reference means (4) with the crankshaft (3) rotatably connected gear (4), in particular a drive gear (4) for driving a motor assembly is. Start learning method according to claim 1 or 2, wherein the reference means (4) more than one reference mark (5), in particular two reference marks (5) are provided, or in particular the number of reference marks (5) equal to the number of cylinders of the reciprocating internal combustion engine (2) is, or the number of reference marks (5) is greater or smaller than the number of cylinders of the reciprocating internal combustion engine (2). Start learning method according to one of the preceding claims, wherein for detecting the reference mark (5) more than one detection means (6), in particular two detection means (6) are provided, or in particular the number of detection means (6) equal to the number of cylinders of the reciprocating internal combustion engine ( 2), or the number of the detection means (6) is greater or smaller than the number of cylinders of the reciprocating internal combustion engine (2). Start learning method according to one of the preceding claims, wherein the reference mark (5) an optical reference mark (5) and / or a magnetic reference mark (5) and / or an electrical reference mark (5) and / or an electromagnetic reference mark (5) and / or a capacitive reference mark (5) and / or an inductive reference mark (5) and / or another reference mark (5) and / or wherein the detection means (6) comprises an optical detection means (6) and / or a magnetic detection means (6) and / or an electrical detection means (6) and / or an electromagnetic detection means (6) and / or a capacitive detection means (6) and / or an inductive detection means (6) and / or another detection means (6). Crank angle sensor unit for determining a crank angle of a reciprocating internal combustion engine (2) according to a method according to one of claims 1 to 5, comprising a with the crankshaft (3) of the reciprocating internal combustion engine (2) in a rotationally effective connection standing reference means (4) with a reference mark (5 ), as well as a detection means (6) with which by interaction with the reference mark (5) an absolute crank angle (7) of the reciprocating internal combustion engine (2) is definable, characterized in that the reference means (4) within the reciprocating internal combustion engine (2), in particular within the stator (8) and / or the crankcase (9) of the reciprocating internal combustion engine (2) is provided. Crank angle sensor unit according to claim 6, wherein the reference means (4) with the crankshaft (3) rotatably connected gear (4), in particular a drive gear (4) for driving a motor assembly is. Crank angle sensor unit according to one of claims 6 or 7, wherein the reference means (4) more than one reference mark (5), in particular two reference marks (5) are provided, or in particular the number of reference marks (5) equal to the number of cylinders Reciprocating internal combustion engine (2), or the number of reference marks (5) is greater or smaller than the number of cylinders of the reciprocating internal combustion engine (2). Crank angle sensor unit according to one of claims 6 to 8, wherein for detecting the reference mark (5) more than one detection means (6), in particular two detection means (6) are provided, or in particular the number of detection means (6) equal to the number Cylinder of the reciprocating internal combustion engine (2), or the number of detection means (6) is greater or smaller than the number of cylinders of the reciprocating internal combustion engine (2). Crank angle sensor unit according to one of claims 6 to 9, wherein the reference mark (5) has an optical reference mark (5) and / or a magnetic reference mark (5) and / or an electrical reference mark (5) and / or an electromagnetic reference mark (5). and / or a capacitive reference mark (5) and / or an inductive reference mark (5) and / or another reference mark (5) and / or wherein the detection means (6) comprises an optical detection means (6) and / or a magnetic detection means ( 6) and / or an electrical detection means (6) and / or an electromagnetic detection means (6) and / or a capacitive detection means (6) and / or an inductive detection means (6) and / or another detection means (6). Reciprocating internal combustion engine having a crank angle sensor unit (10) according to one of claims 6 to 10 for carrying out a starter learning method (1) according to one of claims 1 to 5.

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