DE102019135344A1 - Method for operating an internal combustion engine arrangement of a vehicle - Google Patents

Abstract

The invention relates to a method for operating an internal combustion engine arrangement (1) of a vehicle (10), the internal combustion engine arrangement (1) comprising an internal combustion engine (2) and a device (3) for changing a compression ratio of the internal combustion engine (2). According to the method, the compression ratio is set before the end of a starting process (200) of the internal combustion engine (2) and as a function of a current state of the internal combustion engine arrangement (1) and / or the current ambient atmospheric conditions.

Description

The present invention relates to a method for operating an internal combustion engine arrangement of a vehicle as well as an internal combustion engine arrangement and a vehicle. The present invention also relates to a computer program product.

Internal combustion engine arrangements are known from the prior art in which a compression ratio of the internal combustion engine is changed in a targeted manner during dynamic operation of the internal combustion engine. However, it is possible that after the internal combustion engine has come to a standstill, compression that is present at the restart time is unsuitable. In particular, this can lead to non-optimal fuel consumption and emissions behavior of the internal combustion engine.

The present invention is therefore based on the object of proposing a method for operating an internal combustion engine arrangement of a vehicle, by means of which a fuel consumption and an emission behavior of the internal combustion engine can be optimized. Furthermore, a corresponding internal combustion engine arrangement is to be proposed.

The problem is solved by the independent claims. The subclaims contain advantageous configurations and developments of the invention.

The method for operating an internal combustion engine arrangement of a vehicle comprises the step of setting a compression ratio of an internal combustion engine before an end (conclusion) of a starting process of the internal combustion engine. The compression ratio of the internal combustion engine is set as a function of a current state of the internal combustion engine arrangement and / or the current ambient atmospheric conditions. The compression ratio of the internal combustion engine is set by a device which is set up to change a compression ratio of the internal combustion engine, in particular before the end (completion) of the starting process of the internal combustion engine.

The internal combustion engine arrangement comprises an internal combustion engine, a device for changing a compression ratio of the internal combustion engine and a control unit. The control unit is set up to control the device for changing the compression ratio in order to set the compression ratio before the end (completion) of a starting process of the internal combustion engine as a function of a current state of the internal combustion engine arrangement and / or the current ambient atmospheric conditions.

A device for changing the compression ratio of the internal combustion engine is for example from the EP 2930329 A1 known.

By setting the compression ratio before the completion of the starting process, it is achieved that a suitable compression ratio is present. In this way, an optimal adaptation to requirements regarding comfort, fuel consumption and emissions behavior is achieved before the end of the starting process.

In the context of the present invention, setting the compression ratio advantageously means that the setting process has been completed / ended. Furthermore, it is advantageously understood to mean a mechanical setting of the compression ratio by the device for changing the compression ratio and not, or at least not only, the determination of a desired value for the compression ratio, for example by a control unit. In other words, setting the compression ratio advantageously means that the device for changing the compression ratio changes the position of a piston, in particular its dead center in the cylinder, so that a piston stroke is changed.

It should also be noted that within the scope of the invention, setting the compression ratio does not include setting the position of the piston for the first time during the assembly of the internal combustion engine. In particular, setting the compression ratio according to the invention does not include setting the position of the piston in an internal combustion engine that has not yet been put into operation.

The term “current” in relation to the state of the internal combustion engine arrangement and the current atmospheric ambient conditions means in particular the state of the internal combustion engine arrangement or the atmospheric ambient conditions at the time of the start of the setting process for the compression ratio.

The compression ratio is preferably set during the starting process or before the start of the starting process of the internal combustion engine.

A starting process of the internal combustion engine begins in an advantageous manner when a crankshaft of the internal combustion engine is moved or rotated from an idle state or a first ignition takes place in a cylinder of the internal combustion engine.

A starting process of the internal combustion engine is advantageously completed / ended when a predetermined idling speed of the internal combustion engine is reached or has been reached. In this case, the internal combustion engine is in steady-state operation within the scope of the present invention.

The compression ratio can thus be set in an advantageous manner before a crankshaft of the internal combustion engine is moved or rotated from an idle state or a first ignition takes place in a cylinder of the internal combustion engine.

According to an alternative preferred embodiment of the invention, the compression ratio can be set after a starting process has begun and before a predetermined idling speed of the internal combustion engine is or has been reached.

An adjustment process for the compression ratio preferably begins when a driver's wish to drive away is recognized. Thus, the setting of the compression ratio can begin at an early point in time, so that a suitable compression ratio is already present at the point in time at which the internal combustion engine starts.

For example, a wish to drive away can be recognized when a vehicle door is opened and / or a position of a headlight and / or a mirror is set and / or a starting device for starting the internal combustion engine is actuated.

For this purpose, a sensor arrangement is preferably provided in the internal combustion engine arrangement, which is set up to detect these processes or, in general, a process that takes place in the vehicle or is relevant for the vehicle and / or the internal combustion engine arrangement.

Furthermore, in the internal combustion engine arrangement, a control unit is preferably provided which is set up to evaluate whether a process detected by the sensor arrangement indicates a wish to drive away.

The current state of the internal combustion engine arrangement preferably includes a current state of the internal combustion engine and / or a current state of an exhaust gas aftertreatment system of the internal combustion engine arrangement.

In particular, the exhaust gas aftertreatment system can have a nitrogen oxide storage catalytic converter and / or an SCR catalytic converter (SCR stands for “selective catalytic reduction”).

The current state of the internal combustion engine preferably includes a current temperature of the internal combustion engine. The current temperature of the internal combustion engine can be, for example, an oil or water temperature of a corresponding circuit of the internal combustion engine.

The current state of an exhaust gas aftertreatment system of the internal combustion engine arrangement preferably includes a current temperature of the exhaust gas aftertreatment system and / or a current loading of the exhaust gas aftertreatment system with nitrogen oxides and / or an ammonia storage level of the exhaust gas aftertreatment system and / or an aging state of the exhaust gas aftertreatment system.

Furthermore, the current atmospheric ambient conditions include a current temperature and / or a current humidity and / or a current pressure of the ambient air.

The internal combustion engine arrangement is particularly suitable and / or configured to carry out the steps of the method described above.

The invention also relates to a vehicle with an internal combustion engine arrangement as described above.

The invention also relates to a computer program which comprises commands which cause the internal combustion engine arrangement described above to carry out the steps of the method described above.

The invention also relates to a control unit which is set up to control the internal combustion engine arrangement described above and to carry out the steps of the method described above.

• 1 ein erfindungsgemäßes Fahrzeug mit einer Brennkraftmaschinenanordnung gemäß einem Ausführungsbeispiel der vorliegenden Erfindung,
• 2 eine vereinfachte, schematische Darstellung des zeitlichen Ablaufs eines erfindungsgemäßen Verfahrens zum Betreiben der Brennkraftmaschinenanordnung aus 1 im zeitlichen Vergleich zu einem Startvorgang der Brennkraftmaschine der Brennkraftmaschinenanordnung, und
• 3 ein vereinfachtes Flussdiagramm des Verfahrens gemäß dem Ausführungsbeispiel der Erfindung.

Further details, features and advantages of the invention emerge from the following description and the figures. Show it:

• 1 a vehicle according to the invention with an internal combustion engine arrangement according to an embodiment of the present invention,
• 2 a simplified, schematic representation of the time sequence of a method according to the invention for operating the internal combustion engine arrangement 1 in a time comparison with a starting process of the Internal combustion engine of the internal combustion engine arrangement, and
• 3 a simplified flow chart of the method according to the embodiment of the invention.

How out 1 can be seen includes the vehicle 10 an internal combustion engine assembly 1 . The internal combustion engine assembly 1 has an internal combustion engine 2 , a device 3 for changing a compression ratio of the internal combustion engine 2 , a sensor array 4th , a control unit 5 and an exhaust aftertreatment system 6th on. In 1 are also a crankshaft 20th , two cylinders 21 and the pistons arranged therein 22nd the internal combustion engine 2 shown schematically.

The control unit 5 is with the internal combustion engine 2 , the device 3 to change the compression ratio of the internal combustion engine 2 and the sensor arrangement 4th information technology connected and set up to control them.

In particular, the exhaust gas aftertreatment system 6th have a nitrogen oxide storage catalytic converter and / or an SCR catalytic converter.

The sensor arrangement 4th is set up for processes to take place in the vehicle 10 to recognize and / or information about the internal combustion engine arrangement 1 and / or the surroundings of the vehicle 10 to determine.

In particular, the sensor arrangement 4th be set up to unlock or open a vehicle door 11 and / or adjusting a position of an exterior mirror 12th and / or adjusting a position of a headlight 13th and / or the actuation of a starting device 14th , for example pressing a start button or inserting an ignition key into an ignition lock of the internal combustion engine 2 to recognize.

Furthermore, the sensor arrangement 4th be set up, atmospheric ambient conditions and / or a state of the internal combustion engine arrangement 1 capture.

The state of the internal combustion engine 2 advantageously comprises a state of the internal combustion engine 2 and / or a state of the exhaust aftertreatment system 6th .

The state of the internal combustion engine 2 includes in particular a temperature of the internal combustion engine 2 . The temperature of the internal combustion engine 2 can for example be an oil or water temperature of a corresponding circuit of the internal combustion engine 2 be.

The condition of the exhaust aftertreatment system 6th the internal combustion engine assembly 1 includes a temperature and / or an aging condition of the exhaust gas aftertreatment system 6th and / or a loading of the exhaust gas aftertreatment system 6th with nitrogen oxides and / or an ammonia storage level of the exhaust gas aftertreatment system 6th .

Furthermore, the atmospheric ambient conditions include a temperature and / or a humidity and / or a pressure of the ambient air.

To recognize the above-mentioned states and / or to determine the above-mentioned information, the sensor arrangement 4th preferably a plurality of sensors 40 on, with each sensor 40 can have a different function.

2 shows a schematic representation of the setting process 100 and the startup process 200 the internal combustion engine 2 on.

According to the proposed method for operating the internal combustion engine arrangement 1 becomes the compression ratio of the internal combustion engine 2 before an end 202 a startup process 200 the internal combustion engine 2 set.

In particular, it follows from 2 that both a beginning 101 as well as an ending 102 the setting process 100 before a start 201 (and thus also before an end 202 ) of the startup process 200 the internal combustion engine 2 takes place.

However, it is also possible, for example, that the end 101 the setting process 100 during the startup process 200 , namely between the beginning 201 and the end 202 the startup process 200 , the internal combustion engine 2 he follows.

Advantageously, the beginning corresponds 201 the startup process 200 the internal combustion engine 2 the time of rotation of the crankshaft 20th from a state of rest or the time when a first ignition takes place in the cylinders 21 .

The end 202 the startup process 200 the internal combustion engine 2 corresponds advantageously to the point in time at which a predetermined idling speed of the internal combustion engine 2 is or has been achieved.

In particular, the compression ratio of the internal combustion engine 2 as a function of a current state of the internal combustion engine arrangement 1 and / or the current ambient atmospheric conditions. The term “current” means that the state of the Internal combustion engine assembly 1 or the ambient atmospheric conditions, as defined above, at the time of the start 101 the setting process 100 the compression ratio can be determined.

3 Fig. 10 shows a flow chart of the setting process 100 according to the proposed embodiment of the method of the present invention.

At the start 101 the setting process 100 is in one step 103 a driver's wish to drive away is recognized. The sensor arrangement can do this 4th for example, detect whether the vehicle door has been unlocked or opened 11 of the driver and / or an adjustment of the position of the headlights 13th and / or an adjustment of the position of the exterior mirrors 12th and / or actuation of the starting device 14th has taken place. The through the sensor arrangement 4th determined information is sent to the control unit 5 forwarded and through the control unit 5 rated.

If through the control unit 5 a driver's wish to drive away is / are determined in a further step 104 the current state of the internal combustion engine arrangement 1 and / or the current ambient atmospheric conditions are determined.

The step 104 but can also be independent of the step 103 respectively.

In step 105 is then based on the determined current state of the internal combustion engine arrangement 1 and / or the determined current atmospheric ambient conditions, the compression ratio of the internal combustion engine 2 set.

The control unit can do this 5 the desired compression ratio of the internal combustion engine 2 determine and the device 3 control so that a stroke or the dead centers, the piston 22nd can be adjusted according to the desired compression ratio.

It should be noted at this point that the device 3 is designed such that this is the compression ratio of the internal combustion engine 2 before the end 202 , especially before the start 201 , the startup process 200 the internal combustion engine 2 can adjust.

To adjust the compression ratio can be done before actually adjusting the position of the piston 22nd preferably a current compression ratio can be determined and compared with the desired compression ratio. Thus, a control of the device 3 in particular only take place if a difference between the current compression ratio and the desired compression ratio is greater than a predetermined threshold.

To the adjustment process 100 must be carried out in the control unit 5 a computer program 50 is stored. The computer program 50 includes in particular commands that cause the internal combustion engine arrangement 1 performs the steps of the procedure previously described.

By adjusting the compression ratio before completing the start-up process 200 the internal combustion engine 2 advantages in terms of comfort (acoustics), fuel consumption and emissions are achieved. In particular when the internal combustion engine is cold started 2 , ie in particular when the current temperature of the internal combustion engine 2 is below a temperature threshold, a suitable setting is particularly relevant to emissions.

List of reference symbols

1

Internal combustion engine assembly

2

Internal combustion engine

3

Device for changing a compression ratio of the internal combustion engine

4th

Sensor arrangement

5

Control unit

6th

Exhaust aftertreatment system

10

vehicle

11

Vehicle door

12th

mirror

13th

Headlights

14th

Starting device

20th

crankshaft

21

cylinder

22nd

piston

40

sensor

100

Adjustment process of the compression ratio

101

Beginning

102

end

103

step

104

step

105

step

200

Starting process of the internal combustion engine

201

Beginning

202

end

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 2930329 A1 [0007]

Claims (9)

A method for operating an internal combustion engine arrangement (1) of a vehicle (10), the internal combustion engine arrangement (1) comprising an internal combustion engine (2) and a device (3) for changing a compression ratio of the internal combustion engine (2), wherein according to the method, the compression ratio before a The end of a starting process (200) of the internal combustion engine (2) is set, the compression ratio being set as a function of a current state of the internal combustion engine arrangement (1) and / or the current ambient atmospheric conditions. Procedure according to Claim 1 , wherein the compression ratio is set during the starting process (200) or before a start (201) of the starting process (200) of the internal combustion engine (2). Method according to one of the preceding claims, wherein a starting process (200) of the internal combustion engine (2) begins when a crankshaft (20) of the internal combustion engine (2) is moved from an idle state or a first ignition in a cylinder (21) of the internal combustion engine (2) ) takes place and / or wherein a starting process (200) of the internal combustion engine (2) is ended when a predetermined idling speed of the internal combustion engine (2) is reached or has been reached. Method according to one of the preceding claims, wherein an adjustment process (100) for the compression ratio begins when a driver's wish to drive away is recognized. Method according to one of the preceding claims, wherein the current state of the internal combustion engine arrangement (1) comprises: • a current state of the internal combustion engine (2), • and / or a current state of an exhaust gas aftertreatment system (6) of the internal combustion engine arrangement (1). Method according to one of the preceding claims, wherein the current atmospheric ambient conditions include a temperature and / or a humidity and / or a pressure of the ambient air. Internal combustion engine arrangement (1) of a vehicle (10), the internal combustion engine arrangement (1) being particularly suitable for the steps of the method according to one of the Claims 1 to 6th the internal combustion engine arrangement (1) comprising: • an internal combustion engine (2), • a device (3) for changing a compression ratio of the internal combustion engine (2), and • a control unit (5) which is set up to control the device (3) to change a compression ratio of the internal combustion engine (2) in order to set the compression ratio before the end of a starting process (200) of the internal combustion engine (2) as a function of a current state of the internal combustion engine arrangement (1) and / or the current ambient atmospheric conditions. Vehicle (10) comprising an internal combustion engine arrangement (1) according to Claim 7 . Computer program (50) comprising instructions which cause the internal combustion engine arrangement (1) to des Claim 7 the procedural steps of the method according to one of the Claims 1 to 6th executes.

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