DE102018217106A1 - Method for operating a drive device of a hybrid vehicle - Google Patents

Abstract

The invention relates to a method for operating a drive device (1) of a hybrid vehicle (2), which has an internal combustion engine (3) and an electric machine (4), the hybrid vehicle (2) depending on a torque request by the internal combustion engine (3) and / or the electric machine (4) is driven. It is provided that in basic operation the hybrid vehicle (2) is driven solely by the electric machine (4), the hybrid vehicle (2) in basic operation being monitored for an expected torque request, and when it is determined that the expected one Torque request exceeds a predetermined limit, the internal combustion engine (3) is preconditioned.

Description

The invention relates to a method for operating a drive device of a hybrid vehicle, which has an internal combustion engine and an electric machine, the hybrid vehicle being driven as a function of a torque request by the internal combustion engine and / or the electric machine.

The invention further relates to a device for operating the drive device.

State of the art

Methods of the type mentioned are known from the prior art. For example, a hybrid vehicle, which has an internal combustion engine and an electric machine, is usually driven by the electric machine when the torque requirement is low, in particular when starting from a standstill or when driving at low speed, for example when driving around town. In the event of a higher torque requirement, which in particular exceeds a torque that can be achieved by the electric machine, for example as a result of accelerating or driving at a higher speed, the internal combustion engine is usually switched on or started, so that the hybrid vehicle is additionally or only driven by the internal combustion engine becomes.

Disclosure of the invention

According to the invention, it is provided that the hybrid vehicle is driven solely by the electric machine in a basic operation, the hybrid vehicle being monitored for an expected torque request in the basic operation, and if it is determined that the expected torque request exceeds a predefinable limit value, the internal combustion engine is preconditioned becomes. The advantage here is that the internal combustion engine is or can be preconditioned early, that is to say before the limit value is reached, by monitoring for the expected torque request. “Preconditioning” here preferably means a process by which the internal combustion engine or at least one component of the internal combustion engine is brought to a predefinable operating temperature or heated. This results in the advantage that when the torque request reaches the limit value, the internal combustion engine is already preconditioned or preheated and can or can be started in a warm operating state. This has advantages with regard to the service life of the internal combustion engine, driving comfort and exhaust gas aftertreatment, because the exhaust gas temperatures required for efficient exhaust gas aftertreatment can thus be achieved. In the present case, “expected torque request” is to be understood as a torque that will only be required from a specific or determinable future point in time. If it is determined that the expected torque request will exceed the predefinable limit value, then in order to ensure early preconditioning, this is activated in particular within a predefinable time interval or point in time before the limit value is reached. This ensures that the internal combustion engine is reliably preconditioned when starting, which only takes place in particular when the torque request reaches the limit value.

It is preferably provided that the expected torque request is determined as a function of a route. The advantage here is that it can or can be determined in a simple manner when preconditioning takes place or should take place, or when an increased torque requirement is to be expected. Depending on the route, a point in time or a position can be determined at which the expected torque request exceeds or will exceed the limit value. This ensures that the preconditioning can be reliably activated, in particular before the specific point in time or the specific position is reached. If, for example, a freeway entrance is determined as the position at which the expected torque request reaches the limit value, preconditioning can be activated early, in particular from a predeterminable distance to the freeway entrance or time until the freeway entrance is reached.

The expected torque request is preferably determined as a function of data acquired and stored during a previous operation of the hybrid vehicle. The advantage here is that it can or can be determined in a particularly convenient manner when preconditioning takes place or should take place. It is not necessary to specify a route, in particular by a user of the hybrid vehicle, since this is in particular automatically determined or recognized. In particular, at least information about a time of day, a day of the week and / or a distance traveled by the hybrid vehicle is meant as data which are recorded and stored during a previous operation. This information is preferably linked to one another. These linked data or information are preferably compared with a current time, a current day of the week and / or a currently traveled route, so that depending on this A comparison is recorded as to whether a currently traveled route corresponds to a route already traveled in the past. If a match is found, then in particular a remaining current route to be traveled is determined or forecast. The expected torque request is preferably determined as a function of the route determined thereby.

It is particularly preferably provided that the expected torque request and / or the limit value is / are specified by a user of the hybrid vehicle. The advantage here is that the user of the hybrid vehicle can influence in particular the activation of the preconditioning. For example, by increasing the expected torque request and / or lowering the limit value, he can cause the preconditioning to be activated earlier than with a previously lower expected torque request and / or a previously higher limit value. The specification is made, for example, by actuating a multifunction display of the hybrid vehicle.

According to a preferred development of the invention, it is provided that the expected torque request is determined as a function of a state of charge of an energy store of the electric machine. Here, too, there is the advantage that it can or can be determined in a simple manner when preconditioning takes place or should take place. Depending on the state of charge, a maximum range that can be traveled by the electric machine can be determined. This ensures that a point in time or a position can be determined at which the state of charge is so critical, for example at zero, that reliable electric driving can no longer be guaranteed. For this purpose, the preconditioning of the internal combustion engine can be reliably activated, in particular before this critical state of charge is reached. The state of charge of the energy store is preferably determined as a function of a current driving behavior of the user.

It is preferably provided that the route is supported as a function of data from a satellite-based navigation system. This has the advantage that the route and / or the current position of the vehicle can be precisely determined. This ensures, in particular, a reliable determination of a position and / or a point in time from which the expected torque request should reach the limit value and / or the preconditioning should be activated.

It is particularly preferably provided that an engine oil is brought to a predeterminable temperature, in particular heated, by the preconditioning. This has the advantage that the engine oil brought to temperature or warms it up ensures sufficient preheating of the internal combustion engine, in particular by distributing the engine oil in a lubricating oil circuit of the internal combustion engine. Preheating the internal combustion engine makes it possible to start the internal combustion engine with immediate load application. The motor oil is preferably brought to the predeterminable temperature by using it as a coolant for the electric machine and / or the energy store. For this purpose, the electric machine is preferably designed as a liquid-cooled electric machine. Alternatively, the motor oil is heated by connecting it to a cooling medium of the electric machine through a heat exchanger. The temperature of the engine oil is preferably monitored by a temperature sensor.

It is preferably provided that an oil pump of the internal combustion engine is activated by the preconditioning. The advantage here is that engine oil is supplied to moving and / or lubricating parts of the internal combustion engine before the internal combustion engine is started. This ensures that the risk of wear of the internal combustion engines or their components is minimized when the internal combustion engine is started. The internal combustion engine can thus be operated efficiently after it has started. The oil pump is preferably driven by the electric machine.

It is particularly preferably provided that the preconditioning entrains the internal combustion engine at least temporarily through the electric machine. The advantage here is that the internal combustion engine is or can be towed up to a predeterminable speed by the electric machine before it is started. The towing or hauling is preferably carried out by at least temporarily closing a coupling device which is connected between the internal combustion engine and the electric machine. This ensures in particular that when the internal combustion engine is started, which takes place in particular by injecting fuel into at least one cylinder of the internal combustion engine, the fuel can be injected with a sufficient system pressure.

The device for operating a drive device of a hybrid vehicle according to the features of claim 10 is characterized by a control device which is designed to carry out the method according to one of claims 1 to 9 when used as intended. It This results in particular in the advantages which have already been explained in connection with the method. Further advantages and preferred features result from what has been described above and from the subclaims.

The internal combustion engine is preferably designed as a diesel engine, gasoline engine or gas engine. The advantage here is that regardless of the type of internal combustion engine, preconditioning is always guaranteed. For a gas engine, this means in particular that preheating or heating by fuel injection is not necessary.

• 1 ein Flussdiagramm zur Durchführung eines Verfahrens zum Betreiben der Antriebsvorrichtung gemäß einem Ausführungsbeispiel und
• 2 eine Vorrichtung zum Betreiben einer Antriebsvorrichtung eines Hybridfahrzeugs gemäß einem Ausführungsbeispiel.

The invention will be explained in more detail below with reference to the drawing. Show this

• 1 a flowchart for performing a method for operating the drive device according to an embodiment and
• 2nd a device for operating a drive device of a hybrid vehicle according to an embodiment.

1 FIG. 12 shows a flow diagram for performing an exemplary method for operating a drive device 1 of a hybrid vehicle 2nd which is an internal combustion engine 3rd and an electric machine 4th has, the hybrid vehicle 2nd depending on a torque request from the internal combustion engine 3rd and / or the electric machine 4th is driven. The drive device 1 is preferably designed as a parallel hybrid. Alternatively, the drive device 1 designed as a power-branching or serial hybrid, in particular a full hybrid. The internal combustion engine 3rd is preferably designed as a diesel engine, gasoline engine and / or gas engine.

In a first step S1 becomes the hybrid vehicle 2nd in a basic operation, especially with a low current torque requirement, solely by the electric machine 4th driven. The torque request or power request takes place in particular as a function of a specification by a user of the hybrid vehicle 2nd , for example depending on an accelerator pedal position. The hybrid vehicle is preferred 2nd as a semi-autonomous or autonomously operated hybrid vehicle 2nd educated. It is preferably provided that the current torque request by an in particular adaptive cruise control system 5 , which is designed to control the speed of the hybrid vehicle 2nd automatically regulated, is specified.

In a second step S2 the hybrid vehicle is monitored in basic operation for an expected torque request. The “expected torque requirement” is to be understood as a torque that will only be required from a specific or determinable future point in time.

The expected torque is determined in particular as a function of a route. For this purpose, the route before the trip begins or during a trip, in particular by the user of the hybrid vehicle 2nd given. The route is preferably dependent on data from a satellite-based navigation system 6 , in particular by a control unit 7 , certainly.

A non-limiting example follows for illustration: The hybrid vehicle 2nd is operated with a low torque requirement in basic operation, for example when driving in a closed town with a permissible maximum speed of 50 km / h. Depending on the data of the satellite-based navigation system 6 It is determined that the permissible maximum speed is lifted from a certain position, for example because the closed town ends at the certain position and a country road or extra-urban road follows from this specific position with a permissible maximum speed of 100 km / h. The expected torque requirement, which is determined as a function of the route, can thus, without being limited to the following embodiments, in particular as a function of a future permissible maximum speed, a determined length of the route and / or a current or future position on the route be determined.

As an alternative or in addition, the expected torque requirement is dependent on during a previous operation of the hybrid vehicle 2nd recorded and stored data determined. For this purpose, it is preferably provided that, in particular, a time, a day of the week and / or a driven route of the hybrid vehicle as data 2nd be recorded and saved. These are preferably linked to one another. The hybrid vehicle points to the acquisition, storage and / or linkage 2nd preferably an evaluation or arithmetic unit 8th on. The evaluation or arithmetic unit is preferably in the control unit 7 integrated. These linked data or information are preferably compared with a current time, a current day of the week and / or a currently traveled route. Depending on the comparison, it is then determined whether the current or previous route corresponds to a route that has been traveled and saved in the past. If a match is found, the remaining current route to be traveled is determined or predicted. For example, it can be used to determine or predict that the user is on the way to work. The expected torque request is then determined as a function of the route thus determined, that is to say in particular as a function of a future predefined speed limit, a determined length of the route and / or a current or future position on the route.

As an alternative or in addition, the expected torque requirement is dependent on a state of charge of an energy store 9 the electric machine 4th certainly. The expected torque request is preferably also determined as a function of a detected driving behavior, in particular a current torque request, of the user. In particular, a range is determined depending on the state of charge and / or driving behavior, which the hybrid vehicle 2nd in basic operation, i.e. solely by the electric machine 4th driven, can travel. The expected torque requirement is then determined depending on the range determined thereby. The state of charge is preferably determined by the control unit 7 certainly. The energy storage 9 is preferably designed as a battery.

Alternatively or additionally, the expected torque request by the user of the hybrid vehicle 2nd given. The user can thus specify in particular when a higher or lower torque request is necessary. This takes place in particular when the user knows before driving or during a driving operation that he will cover a distance beyond the electrical range or one above a power level of the electric machine 3rd will need lying power requirements.

In a third step S3 it is determined whether the expected torque request exceeds a predefinable limit. The predeterminable limit value is in particular dependent on one from the electric machine 4th maximum affordable torque. Alternatively or additionally, the predefinable limit value is specified by the user, for example by actuating a multifunction display of the hybrid vehicle 2nd . Furthermore, alternatively or additionally, the predefinable limit value depends on a range which the hybrid vehicle has 2nd in basic operation, i.e. by the electric machine 4th , can cover. Preferably, the control unit 7 determines whether the expected torque request exceeds the predefinable limit.

If, for example, the expected torque is determined as a function of the travel distance and a future permissible maximum speed is determined as a function of the determined travel distance, which is achieved by a drive by the electric machine 4th alone cannot be achieved, it is determined that the expected torque request exceeds or will exceed the predefinable limit value.

If it is determined that the expected torque request exceeds the limit value, then in a fourth step S4 the internal combustion engine 4th preconditioned. “Preconditioning” here means a process by which the internal combustion engine 3rd or at least one component of the internal combustion engine 3rd is brought to a predetermined operating temperature or heated. Preconditioning thus ensures that the internal combustion engine 3rd is only started in a warm operating state. To ensure early preconditioning, this is activated in particular within a predefinable time interval or point in time before the limit value is reached, in particular before a position is reached at which the limit value is exceeded. Starting the internal combustion engine 3rd in particular only occurs when the torque request reaches the limit value.

Pre-conditioning in particular brings an engine oil to a predeterminable temperature. The motor oil is preferably brought to the predeterminable temperature by using it as a coolant for the electric machine 4th and / or the energy store 9 the electric machine 4th is used. For this purpose, the electric machine is preferred 4th as a liquid-cooled electrical machine 4th educated. Alternatively, the motor oil is heated by the electrical machine using a heat exchanger with a cooling medium, for example water 4th is / is connected. The temperature of the engine oil is preferably monitored by at least one temperature sensor. Sufficient preheating of the internal combustion engine is ensured, in particular, by the engine oil brought to temperature or warmed up 3rd , in particular by distributing the engine oil in a lubricating oil circuit of the internal combustion engine 3rd , guaranteed. This has the advantage, for example, that fuel is placed in a warm combustion chamber of the internal combustion engine 3rd can be injected. This enables the exhaust gas temperatures required for sustainable exhaust gas aftertreatment / purification to be achieved. This reduces emissions, saves costs, conserves resources and reduces space requirements.

As an alternative or in addition, an oil pump is made by preconditioning 10th the internal combustion engine 3rd activated. Preferably the oil pump 10th through the electric machine 4th driven. The advantage here is that the engine oil is movable and / or lubricating parts of the internal combustion engine 3rd is supplied before the internal combustion engine 3rd is started. The activation and / or deactivation of the oil pump 10th is preferably carried out by the control unit 7 .

Alternatively or additionally, the internal combustion engine is made by preconditioning 3rd at least temporarily by the electric machine 4th dragged along. The entrainment is preferably carried out by at least temporarily closing a coupling device 11 , in particular a separating clutch, which is between the internal combustion engine 3rd and the electric machine 4th is switched. The advantage here is that the internal combustion engine 3rd through the electric machine 4th is or can be towed to a predeterminable speed before it is started. Controlling the clutch device 11 for closing and / or opening is preferably carried out by the control unit 7 .

The preconditioning of the internal combustion engine 3rd has the advantage of extending the life of the internal combustion engine 3rd elevated. In addition, preconditioning also increases driving comfort and driving safety. If the internal combustion engine is started or switched on 3rd , in particular a diesel engine, in an acceleration phase of the hybrid vehicle 2nd , so the power requirement on the internal combustion engine increases 3rd with a high gradient. In particular, pressure and speed increase sharply. This high gradient sets in the case of an unconditioned internal combustion engine 3rd at a time when the internal combustion engine 3rd , especially the diesel engine, still reacted sluggishly. This can lead to a noticeable drop in performance and thus a loss of comfort. In addition, such irregular acceleration can increase the risk of a rear-end collision. In addition, when a non-preconditioned internal combustion engine is switched on 3rd the risk that an acceleration stall during an acceleration process, for example overtaking, will endanger road users.

Furthermore, the preconditioning has the advantage that it is possible to drive purely electrically in emission-relevant areas and / or on short journeys, in particular depending on data from the satellite-based navigation system 6 stopping or deactivating the internal combustion engine 3rd done automatically or can be done. On long journeys and / or when a torque request exceeds the limit, the performance and range of the internal combustion engine can be affected 3rd be resorted to. It is also provided that the energy store 9 on routes between two emission-relevant areas, for example a place of residence and a place of work, by the internal combustion engine 3rd can be charged efficiently.

In the area of commercial vehicles, especially in delivery traffic, a combination of performance, range values and emission-free driving is particularly interesting, since this is the only way to avoid reloading goods on a transport route between a long distance, for example a motorway route, and a short route, for example an inner-city route can be. In particular, the high mileage of commercial vehicles required in this area ensures that the internal combustion engine is operated gently 3rd necessary.

Is the internal combustion engine 3rd Designed as a gas engine, there is the advantage that the preconditioning of the gas engine by the electric machine 4th takes place or can take place. Preheating the gas engine by gasoline or diesel injection is therefore not necessary. In particular, the preconditioning itself makes the gas ignitable. This ensures that in gas engines in connection with at least one electric machine 4th there is no need for conventional injection equipment. An entire periphery of liquid fuel, in particular liquid fuel for operating a gasoline or diesel engine, can also be dispensed with, in particular filters, lines, tanks and / or pumps. In addition, the total emissions of the gas engine are in connection with an electric machine 4th compared to a connection of the gas engine and an injection of gasoline or diesel fuel significantly lower.

2nd shows a device in a simplified representation 12th to operate the drive device 1 of the hybrid vehicle 2nd the internal combustion engine 3rd and the electric machine 4th having. Between the internal combustion engine 3rd and the electric machine 4th is the coupling device 11 arranged. Furthermore, the hybrid vehicle 2nd a transmission not described here 13 , a differential 14 as well as drive wheels 15 , 16 for driving the hybrid vehicle 2nd on. The device 12th includes the control unit 7 , which is designed to carry out the method described above. By the control unit 7 be particularly the operation of the internal combustion engine 3rd , the electric machine 4th , the coupling device 11 as well as other components of the hybrid vehicle 2nd , especially the oil pump 10th , controlled.

The diesel engine is preferably operated with synthetically produced CO2-neutral fuel.

Preferably the cruise control system 5 in the control unit 7 integrated. The speed or the torque specification is preferably determined by the hybrid vehicle, which can be operated partially autonomously or autonomously 2nd depending on data, in particular of the satellite-based navigation system 6 and / or a traffic sign recognition system.

Claims (11)

Method for operating a drive device (1) of a hybrid vehicle (2), which has an internal combustion engine (3) and an electric machine (4), the hybrid vehicle (2) depending on a torque request by the internal combustion engine (3) and / or the electric machine ( 4) is driven, characterized in that the hybrid vehicle (2) is driven in a basic operation solely by the electric machine (4), the hybrid vehicle (2) being monitored for an expected torque request in the basic operation, wherein if it is determined, that the expected torque requirement exceeds a predeterminable limit value, the internal combustion engine (3) is preconditioned. Procedure according to Claim 1 , characterized in that the expected torque request is determined depending on a route. Method according to one of the preceding claims, characterized in that the expected torque request is determined as a function of data acquired and stored during a previous operation of the hybrid vehicle (2). Method according to one of the preceding claims, characterized in that the expected torque request and / or the limit value is / are specified by a user of the hybrid vehicle (2). Method according to one of the preceding claims, characterized in that the expected torque request is determined as a function of a state of charge of an energy store (9) of the electric machine (4). Procedure according to Claim 2 , characterized in that the route is determined as a function of data from a satellite-based navigation system (6). Method according to one of the preceding claims, characterized in that an engine oil is brought to a predeterminable temperature by the preconditioning. Method according to one of the preceding claims, characterized in that an oil pump (10) of the internal combustion engine (3) is activated by the preconditioning. Method according to one of the preceding claims, characterized in that, due to the preconditioning, the internal combustion engine (3) is entrained at least temporarily by the electric machine (4). Device (12) for operating a drive device of a hybrid vehicle (2), which has an internal combustion engine (3) and an electric machine (4), the hybrid vehicle (2) depending on a torque request from the internal combustion engine (3) and / or the electric machine ( 4) can be driven, characterized by a control device (7) which is designed to, when used as intended, the method according to one of the Claims 1 to 9 perform. Device after Claim 10 , characterized in that the internal combustion engine (3) is designed as a diesel engine, gasoline engine or gas engine.

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