DE102011015539A1 - Method for operating powertrain of motor home that is utilized in camping site, involves switching-on operation mode, where engine is switched-on, and battery is charged in operation mode if charging state lies above threshold value - Google Patents

Abstract

The method involves driving a powertrain (2) using a battery (4) i.e. lithium-ion battery, in operation mode if charging state of the battery lies above a threshold value, where the state is detected by an electrical sensor (17). Another operation mode is switched-on by a manual switch (11) e.g. push button, and menu function of a graphic display, according to a manual command, where a combustion engine (3) is switched-on, and the battery is charged in the latter mode if the state lies above the threshold value. An electromotor (5) is driven by the battery in the former operation mode. The graphic display is designed as a touch screen. Independent claims are also included for the following: (1) a drive system for a motor car (2) a motor car.

Description

The invention relates to a method for operating a drive train of a motor vehicle, a drive system for a motor vehicle and a motor vehicle.

A motor vehicle with an internal combustion engine as the sole power source also has a battery which is used to start the internal combustion engine and to supply the onboard power consumers, such as lamps. The battery can also be used to power vehicle-independent power consumers.

The DE 10 2007 051 362 A1 discloses a motor vehicle having a fuel cell system as a power source, wherein electrical energy is transferred from the fuel cell system of a motor vehicle to a DC / AC converter and from an output of the DC / AC converter via an interface to a vehicle-independent power consumer. This interface is installed in the outer skin of the motor vehicle or in an extension of the same, so that the power consumers can be supplied with closed vehicle doors, closed windows and closed trunk.

The object of the invention is to provide a method in which a vehicle-independent power consumers can be reliably supplied with power.

This object is achieved by the subject matter of the independent claims. Further advantageous developments are the subject of the dependent claims.

A method of operating a powertrain of a motor vehicle having an internal combustion engine and a traction battery is disclosed wherein an axle drive train of the motor vehicle may be driven above the driveline with the engine or with the traction battery. In a first operating mode, the drive train is exclusively driven by the drive battery when a charge state L _{B of} the drive _battery is above a limit value L _MIN . After a manual command, a second operating mode is turned on, in which the internal combustion engine is turned on and the drive battery is charging, while the state of charge L _B of the drive battery is above the limit L _MIN .

This method can be used in various types of motor vehicles, wherein the motor vehicle has two power sources, namely a drive battery and an internal combustion engine. These types of motor vehicles may be referred to as hybrid vehicles. The two power sources may be arranged in parallel to or in series with the final drive train.

Herein, a drive battery refers to a battery that directly drives the vehicle and in particular the final drive train during normal operation.

In one embodiment, the method is used in series in a conventional EREV (Extended Range Electric Vehicle) system, that is, a combined electric and combustion powered vehicle. In this type of hybrid vehicle, the internal combustion engine drives a generator, the generator drives an electric motor and the electric motor drives the final drive train.

During normal operation of this type of EREV vehicle, the vehicle is operated by the traction battery until the traction battery is depleted, or the state of charge of the traction battery drops below a threshold value. In this case, the traction battery is decoupled from the driveline, the internal combustion engine is turned on and used to drive the electric motor above the generator and, consequently, the final drive train.

If, on request, a manual command is issued while the vehicle is being driven, then according to the invention the drive battery is charged as much as possible by the internal combustion engine. This second mode of operation is also performed when the state of charge of the traction battery is sufficiently high that during normal operation the traction battery would exclusively drive the final drive train and the internal combustion engine would remain off. The switch thus allows the driver to override the automatic switching between the power sources.

Such a method has the advantage that the available in standby battery capacity for the additional consumers is maximally possible without unwanted noise or exhaust emissions occur in stationary mode, since the charging of the drive battery while driving and thus takes place during regular operation of the internal combustion engine. This ensures that the vehicle-independent consumers can be supplied with electrical energy during standstill operation of the motor vehicle without having to operate the motor of the motor vehicle for this purpose. The method can also be implemented simply and inexpensively by means of already existing systems and components of a conventional EREV system, without having to carry out an expensive and complicated conversion.

The second mode of operation can be turned on by the operation of a switch. This allows the driver to charge the traction battery as desired, even if the state of charge of the traction battery is above the limit at which the internal combustion engine is switched off in normal operation because the traction battery exclusively drives the final drive train. This switch can be mounted in the interior of the vehicle, for example, it can be integrated in the instrument panel.

By the switch, the drive battery can always be charged if the electrical energy stored therein in the subsequent stationary operation of the vehicle for vehicle-independent consumers with the largest possible battery capacity should be available.

In one embodiment, the driving battery is charged in the second operating mode so that the state of charge is at least 90% of the maximum charge state L _MAX. Furthermore, the electrical energy can be stored in the drive battery until it is fully charged.

Thus, it can be ensured that a maximum battery capacity of the drive battery for the additional, vehicle-independent consumers is available during standstill operation of the motor vehicle. This also ensures that the drive battery, as soon as it is fully charged, no more electrical energy is supplied and the electrical energy can be fully used for driving the motor vehicle, whereby the efficiency of the overall system is increased.

When the traction battery and the engine are arranged in series, in the first operating mode, the traction battery drives the electric motor and the electric motor drives the final drive train. In this embodiment, in the second mode of operation, the internal combustion engine drives the generator, the generator drives the electric motor, and the electric motor drives the final drive train.

As mentioned above, the internal combustion engine serves as a range extension system. In this case, the powertrain is switched to a third operating mode in which the internal combustion engine drives the final drive train when, in the first operating mode, the charge state of the drive _battery falls below the limit value L _MIN . The motor vehicle can thus continue driving when the traction battery is empty, or the state of charge falls below a limit L _MIN . Typically, the traction battery will not be dropped when empty, as this will affect the life and capacity of the battery. Thus, the limit L _MIN , at which the traction battery is decoupled from the driveline and instead the driveline is driven by the engine, is above an empty state of charge. The limit value L _MIN may be, for example, 20% to 30% of the maximum state of charge L _MAX .

In one embodiment, a controller is used to switch from the first mode of operation to the third mode of operation. This switching can be performed automatically. The state of charge of the drive battery can be measured by a sensor and transmitted to the control unit. The control unit can switch in this case, depending on the state of charge, from the first to the third operating mode.

The sensor can be realized, for example, by an electrical sensor which comprises a detection unit for detecting the state of charge of the drive battery and emits therefrom an electrical signal which is indicative of the value of the detected state of charge. A large number of such sensors are already integrated in many motor vehicles, which is why sensors can be used in a cost-effective and user-friendly manner and with low requirements for the installation space for reading out the state of charge of the drive battery.

A drive system for a motor vehicle is also indicated, wherein the drive system comprises an internal combustion engine, a drive battery and a control unit, and an axle drive train of the motor vehicle can be driven via the drive train with the internal combustion engine or with the drive battery. The control unit is designed such that in a first operating mode, the drive train is driven exclusively with the drive battery, when a charge state L _{B of} the drive _battery is above a limit L _MIN , and after receiving a manual command, the control unit turns on a second operating mode, in which Combustion engine is switched on and the drive battery is charging, while the state of charge L _B of the drive battery is above the limit L _MIN .

The control unit is formed so that the axle drive train is driven solely with the drive battery when the drive battery is sufficiently charged. In this operating mode, the internal combustion engine is switched off. Thus, the exhaust emissions of the motor vehicle are reduced.

However, the control unit is designed so that upon receipt of a manual command, it turns on the second mode of operation, in which it The internal combustion engine starts, even if the state of charge is above the limit value and would normally only drive the final drive train in the first operating mode. This second mode of operation is used to charge the traction battery even when the state of charge is above the limit L _MIN . Consequently, as desired, the state of charge of the drive battery can be kept as high as possible. This stored electrical energy can be used, for example, at later standstill of the motor vehicle to supply vehicle-independent power consumers, without turning on the engine.

The drive system may include a switch that transmits the manual command to turn on the second mode of operation to the control unit. The driver or an occupant of the motor vehicle may operate the switch to selectively engage the drive system in the second mode of operation.

The switch can be designed as a pushbutton or can be a menu function of a graphic display designed as a touchscreen.

This ensures an ergonomically favorable operation for the driver of the motor vehicle. An electrical switch may have a designed as a rocker and / or button actuator, which acts with appropriate actuation by the driver switching to a contact system. The contact system may be configured in a conventional manner as an electromechanical contact system. It is particularly cost effective if the contact system of the switch consists of a switching mat. Finally, to further improve the operability of the switch can be equipped with a function and / or symbol lighting for the actuator.

Alternatively, the controllable switch may be a menu function of a graphic display designed as a touchscreen. The driver is thus provided with an operating element having a plurality of selectable menus, functions and / or function values which has a surface that can be detected ergonomically by the driver and via which the selection can be carried out by a local movement or contact with the surface. The surface can be changed in its shape according to the selected and / or selectable menu function and / or the function value.

In a further embodiment, the controllable switch but also as other manually interactive device, for example in the form of switches, buttons, rotary switches, toggle switches and the like may be formed. Also, the function of the controllable switch, for example, be adopted by a preferably existing means for speech recognition, as this brings a particularly comfortable and convenient operation for the driver.

In a further embodiment, the drive system comprises a sensor for measuring the state of charge of the drive battery, which is connected to the control unit. The control unit may switch between the first and third modes of operation depending on the measured state of charge.

A motor vehicle comprising a drive system according to one of the preceding embodiments is also indicated.

In one embodiment, the motor vehicle further comprises an interface, such as a socket, can be connected to the motor vehicle independent power consumers and supplied with the drive battery. This interface can be connected via a DC / AC converter to the drive battery, so that power consumers can be supplied with alternating current. The control unit can also be designed such that the motor vehicle-independent power consumers can be supplied with the drive battery while the internal combustion engine is switched off. The interface can be arranged in the outer skin of the motor vehicle, so that it can be used with the doors, trunk, bonnet, etc. of the motor vehicle closed.

The vehicle may also include an interface, such as a plug, over which the drive battery may be charged with an external power source. It is also possible to combine this interface with the interface for the vehicle-independent power consumers.

The drive battery may be formed as a battery unit that includes a plurality of batteries. In this case, the fact is used that motor vehicle batteries often have two or more battery units and in particular battery cells. These battery cells are connected via cell contacts to a voltaischen column in series or in parallel, wherein each battery unit is provided to this adapted electrical charging device. As a result, the service life and performance of the drive battery can be further increased.

Such a motor vehicle has the advantage that in the stationary operation of the vehicle the largest possible amount of stored electrical energy is available in the drive battery in order to supply vehicle-independent consumers with electricity. This allows electrical energy be used externally, without the necessary for the generation of electrical energy internal combustion engine must be operated locally, which, for example, on campsites, disturbing noises or occurring exhaust emissions are avoided.

Also, a vehicle based on an EREV system can be easily and inexpensively upgraded by rebuilding the existing system to use the system without the need for costly and expensive conversions.

In one embodiment, the motor vehicle is a motorhome. In particular, motorhomes include a variety of electrical appliances and lamps, such as TV, navigation system or interior lighting, the necessary electrical effort in a motorhome tends to be greater than a house installation. To avoid disturbing noise or exhaust emission occurring, for example, it is advantageous on campsites not to operate the internal combustion engine necessary for generating the electrical energy on site, but to charge the supply of vehicle-independent consumer drive battery as much as possible while driving.

Furthermore, such a drive system can also be used in other vehicles, for example in common passenger cars.

In summary, it should be noted that the present application, a method for operating a powertrain of a motor vehicle is specified, which ensures an effective and comfortable charging a drive battery, so that in standby mode of the motor vehicle, the available battery capacity of the drive battery is maximally possible.

This can be realized by storing a large part of the electrical energy generated by the internal combustion engine and the generator in the traction battery while driving, and thus not being used mainly for driving the motor vehicle, in contrast to normal operation. Furthermore, a controllable switch can be integrated into the drive system, so that the driver can ensure if necessary himself that the drive battery is maximally charged if the electrical energy in the subsequent stationary operation for vehicle-independent consumers should be available.

The invention will now be explained in more detail with reference to the accompanying figures.

1 shows a schematic view of a vehicle with a drive train which is drivable with two different power sources;

2 shows a schematic view of the drive train of 1 which is driven in a first mode of operation with a first power source,

3 shows a schematic view of the drive train of 1 powered with the alternative power source,

4 shows a schematic view of the drive train of 1 which is powered in a second mode of operation.

1 shows a schematic view of a vehicle 1 with a powertrain 2 that with two different power source 3 . 4 is drivable. Vehicles optionally with one of the two different power sources 3 . 4 are drivable, are also referred to as hybrid vehicles. As power sources, the vehicle points 1 this embodiment, an internal combustion engine 3 and a drive battery 4 on.

In this embodiment, the drive train 2 an electric motor 5 on, the one axle drive train 6 and consequently at least two wheels 7 of the vehicle 1 drives. The drive battery 4 is with the electric motor 5 connected to drive this. The internal combustion engine 3 is about a generator 8th with the electric motor 5 connected to drive this.

The generator 8th is also with the drive battery 4 connected so that electrical energy coming from the generator 8th is generated and not by the electric motor 5 to drive the vehicle 1 is used in the drive battery 4 can be introduced to the drive battery 4 charge.

A control unit 9 is also stated with the drivetrain 2 operated in different operating modes.

In this embodiment, the power sources, ie the internal combustion engine 3 and the drive battery 4 , arranged in a so-called row, so that both power source the electric motor 5 driving the axle drive train 6 drives.

The method of operating the powertrain 2 However, as will be explained in more detail below, it is not limited to this type of hybrid vehicle, and may also be used in so-called parallel hybrid vehicles where an internal combustion engine and a traction battery each directly drive the axle drive train.

The vehicle 1 will be in normal operation with the drive battery 4 driven when a state of charge L _{B of} the drive battery 4 above a limit L _MIN . During operation of the vehicle 1 with the drive battery 4 decreases with increasing range or operating time of the charge state L _{B of} the drive battery 4 more and more. When a state of charge L _{B of} the drive battery 4 falls below a predetermined limit L _MIN , for example 20 to 30% of the maximum value L _MAX , becomes the traction battery 4 from the electric motor 5 uncoupled, the internal combustion engine 3 switched on and the internal combustion engine 3 used the generator 8th and the electric motor 5 and thus the vehicle 1 drive. The range of the vehicle 1 is increased while the drive battery 4 can be recharged from an external source.

The drive battery 4 may be formed, for example, as a lithium-ion battery. The drive battery 4 may also comprise a plurality of separate battery units which are connected in parallel or in series with each other. The drive battery is charged 4 usually via an external power grid with the help of an electrical charging device, which is schematically in 1 with the reference number 10 is shown. This charging device 10 has an AC / DC converter, not shown.

The vehicle 1 also has a switch 11 which is manually operated by the driver. The desk 11 is thus in the vehicle interior 12 arranged and may be formed for example as a push-button or as a menu function via a touch screen. This switch 11 allows the driver to request the internal combustion engine 3 can turn on, even if the state of charge L _{B of} the drive battery 4 is at a value, for example L _MIN , in the normal operation of the drive battery 4 the final drive train 6 should drive. This operating mode can be used to power the drive battery 4 with the internal combustion engine 3 so that the state of charge L _B is kept as high as possible. Consequently, in the drive battery 4 stored energy will be used later when the internal combustion engine 3 is off.

This stored energy could be used, for example, during a campsite stay to power the vehicle-independent power consumers, such as lights, a refrigerator, etc. This is advantageous if it is not allowed or desired to generate power through the running internal combustion engine.

For this purpose, the vehicle 1 another supply system 13 on, that's a power outlet 14 for a vehicle-independent power consumers, with the drive battery 4 connected is. The supply system 13 may also include a DC / AC converter so that power consumers that consume AC power with the DC drive battery 4 can be supplied.

The 2 to 4 show schematic representations of the various operating modes of the drive train 2 of the 1 ,

Components with the same functions or construction as in 1 bear the same reference numerals and will not be explained separately.

2 shows a schematic view of the drive train 2 of the 1 operating in a first operating mode with the drive battery 4 is driven as a power source. The manual switch 11 is off, as indicated by the word "off" in the figures, and the traction battery 4 has a state of charge L _B , which is above the predetermined limit L _MIN , at which the internal combustion engine 3 automatically from the control unit 9 is started. In this embodiment, the state of charge L _{B is} at least 50% of the maximum state of charge L _MAX .

In this first mode of operation drives the drive battery 4 the electric motor 5 on, which is schematically indicated by the arrow 15 is shown. The electric motor 5 drives the final drive train 6 of the vehicle 1 to what with the arrow 16 is shown schematically. A sensor 17 transmits the current state of charge L _{B of} the drive battery 4 to the control unit 9 what with the arrow 18 is shown.

The control unit 9 is also with the internal combustion engine 3 , the generator 8th and the electric motor 5 connected, what with the arrows 19 . 20 . 21 is shown in the figures, between the power sources 3 . 4 to switch over.

3 shows a schematic view of the drive train 2 of the 1 that with the alternative power source, ie by the internal combustion engine 3 , is driven. In this alternative mode of operation is the manual switch 11 switched off and the drive battery 4 has a state of charge L _B , which is below the predetermined limit L _MIN , for example 50% or 30% of the maximum state of charge L _MAX .

If the control unit 9 by means of the sensor 17 determines that the state of charge L _{B of} the drive battery 4 is below this limit L _MIN , the control unit switches 9 the drive battery 4 off and the internal combustion engine 3 automatically, so that the final drive train 6 no longer from the drive battery 4 is driven, but with the internal combustion engine 3 over the generator 8th and the electric motor 5 , This power path is with the arrows 22 . 23 . 24 in the 3 shown. In the event that not all the electrical energy generated for driving the vehicle 1 is used, the remaining energy can be fed into the drive battery, as with the arrow 25 is shown.

This alternate mode of operation is used to determine the range of the vehicle 1 between charging the drive battery 4 with an external power source to increase, so that the vehicle 1 does not come to a halt when driving the stored energy of the drive battery 4 is exhausted. The drive battery 4 will later be fully charged with the external source, typically the grid, for example at night.

4 shows a schematic view of the drive train 2 of the 1 which is powered in a second mode of operation. In this second mode of operation is the manual switch 11 turned on, what with the word "ONE" in the 4 is shown, and the drive battery 4 has a state of charge L _B , which is above the predetermined limit L _MIN . As with the first mode of operation of the 2 Is the state of charge L _{B of} the drive battery at least 50% of the maximum state of charge L _MAX .

Unlike in the first mode of operation of 2 However, in this second operating mode, the internal combustion engine 3 switched on, although the drive battery 4 has enough stored energy to the vehicle 1 to be able to drive. The electrical energy with the internal combustion engine 3 and the generator 8th is mainly not used to drive the final drive train 6 but used to the drive battery 4 to charge, as with the arrow 25 shown. This ensures that the state of charge L _{B of} the drive battery 4 above a value of 90% of the maximum state of charge L _MAX . The drive battery 4 can simultaneously drive the axle 6 drive, as with the arrows 15 and 16 shown graphically.

This can ensure that the drive battery 4 loaded as much as possible at the request of the driver. In the following stationary operation of the vehicle 1 can be used on this energy and vehicle-independent consumers are supplied with electrical energy.

LIST OF REFERENCE NUMBERS

1

vehicle

2

powertrain

3

internal combustion engine

4

traction battery

5

electric motor

6

final drive

7

wheel

8th

generator

9

control unit

10

Interface for external power source

11

switch

12

Vehicle interior

13

supply system

14

Interface for vehicle-independent power consumers

15

arrow

16

arrow

17

sensor

18

arrow

19

arrow

20

arrow

21

arrow

22

arrow

23

arrow

24

arrow

25

arrow

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102007051362 A1 [0003]

Claims (15)

Method for operating a drive train ( 2 ) of a motor vehicle ( 1 ), which has an internal combustion engine ( 3 ) and a drive battery ( 4 ), wherein an axle drive train ( 6 ) of the motor vehicle ( 1 ) above the drive train ( 2 ) with the internal combustion engine ( 3 ) or with the drive battery ( 4 ) is drivable, wherein in a first operating mode, the drive train ( 2 ) exclusively with the drive battery ( 4 ) is driven when a state of charge L _{B of} the drive battery ( 4 ) is above a limit L _MIN , and after a manual command, a second operating mode is turned on, in which the internal combustion engine ( 3 ) is switched on and the drive battery ( 4 ) while the state of charge L _{B of} the drive battery ( 4 ) is above the limit L _MIN . Method according to claim 1, wherein the second mode of operation is achieved by the actuation of a switch ( 11 ) is turned on. Method according to claim 1 or 2, wherein in the second operating mode the drive battery ( 4 ) is charged so that the state of charge is at least 90% of the maximum state of charge L _MAX . Method according to one of claims 1 to 3, wherein in the first operating mode, the drive battery ( 4 ) an electric motor ( 5 ) that drives the final drive train ( 6 ) drives. Method according to one of claims 1 to 4, wherein in the second operating mode of the internal combustion engine ( 3 ) a generator ( 8th ) and the generator ( 8th ) an electric motor ( 5 ) that drives the final drive train ( 6 ) drives. Method according to one of claims 1 to 5, wherein, when in the first operating mode, the charge state L _{B of} the drive _battery falls below the limit value L _MIN , the drive train ( 2 ) is switched to a third operating mode, in which the internal combustion engine ( 3 ) the final drive train ( 6 ) drives. Method according to one of the claims 6, wherein a control unit ( 9 ) is used to switch from the first operating mode to the third operating mode. The method of claim 7, wherein the state of charge of the drive battery ( 4 ) by a sensor ( 17 ) and transmitted to the control unit. Drive system ( 2 ) for a motor vehicle ( 1 ) comprising an internal combustion engine ( 3 ), a drive battery ( 4 ) and a control unit ( 9 ), where an axle drive train ( 6 ) of the motor vehicle ( 1 ) above the drive train ( 2 ) with the internal combustion engine ( 3 ) or with the drive battery ( 4 ) is driven, the control unit ( 9 ) is designed such that in a first operating mode the drive train ( 2 ) exclusively with the drive battery ( 4 ) is driven when a state of charge L _{B of} the drive battery ( 4 ) is above a limit L _MIN , and upon receipt of a manual command, the control unit ( 9 ) in a second operating mode of the drive train ( 2 ), in which the internal combustion engine ( 3 ) is switched on and the drive battery ( 4 ) while the state of charge L _{B of} the drive battery ( 4 ) is above the limit L _MIN . Drive system according to claim 9, wherein the drive system ( 2 ) a switch ( 11 ), with which the command for switching into the second operating mode to the control unit ( 9 ) is transmitted. Drive system according to claim 10, wherein the switch ( 11 ) is designed as a pushbutton or a menu function of a graphic display designed as a touch screen. Drive system according to claim 9 or 10, wherein the drive system ( 2 ) a sensor ( 17 ) for measuring the state of charge of the drive battery ( 4 ) connected to the control unit ( 9 ) connected is. Motor vehicle ( 1 ) comprising a drive system ( 2 ) according to any one of claims 9 to 12. Motor vehicle ( 1 ) according to claim 13, further comprising an interface ( 14 ), connectable to the motor vehicle-independent power consumers and with the drive battery ( 4 ) are available. Motor vehicle ( 1 ) according to claim 14, wherein the motor vehicle independent power consumers with the drive battery ( 4 ), while the internal combustion engine ( 3 ) is switched off.

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