DE102013224838A1 - System for operating one or more ancillary components of a motor vehicle with an electric machine and method therefor - Google Patents

Abstract

The invention relates to a system (1) for operating one or more ancillary units (27) of a motor vehicle with an electric machine (2) comprising a shaft (3) with a first shaft section (4) and a second shaft section (5) the first shaft portion (4) with an internal combustion engine (30) via a torque transmitting device is operatively engageable and the second shaft portion (5) as a drive shaft for a motorized operation of the electric machine (2) for driving the auxiliary unit (27) is formed with a Lockable coupling (17) between the first and second shaft sections (4, 5), with a control (6) with power electronics for a motor and generator operation of the electric machine (2), wherein the controller (6) between an electrical energy store (8) and the electric machine (2) is switchable, so that the electric machine (2) of the controller (6) is controllable and controllable, and the St (6) can be brought into communication contact with a superordinate internal combustion engine control (10), from which control commands to the controller (6) are transferable, wherein the closable clutch (17) from the controller (6) or the engine control (10) is controllable.

Description

State of the art

The invention relates to a system for operating one or more ancillary components of a motor vehicle with an electric machine having a torque transmission device, which can be brought into operative connection with an internal combustion engine, wherein the electrical machine is designed for a regenerative operation. The invention also relates to a method for operating a previously described system.

In order to air-condition vehicles with, for example, a start-stop system, storage evaporators, which are also called high-performance evaporators, have been developed. With such a storage evaporator, the climate comfort in the vehicle should be maintained in 95% of all stop phases in city traffic. Such storage evaporators require an additional space in the climate box with up to 30% larger installation space compared to standard evaporators. They have an additional weight, are slow in dynamics compared to the standard evaporator and do not have a constant temperature profile during stop operation. Another use of storage evaporator takes place in a "sailing operation" of the internal combustion engine, if under critical conditions longer bridging times must be provided, such as in start-stop operation.

It is known to provide an air conditioning system for motor vehicles with a refrigeration compressor which is driven by the driving engine of the vehicle during driving operation of the vehicle. In order to allow cooling even when the drive engine for the interior, the refrigeration compressor is driven at standstill of the vehicle by a powered from the electrical system electric motor. The drive shaft of the refrigeration compressor is formed in addition to the pulley for the drive from the vehicle engine with another pulley, which is connected via a toothed belt or V-belt with the electric motor.

The DE 102 26 089 A1 describes a vehicle air conditioner in which an electric motor generator having both a generator function and a motor function for driving a compressor of an air conditioner is provided when an internal combustion engine is stopped. The electric motor generator is connected via a belt drive with the internal combustion engine and the compressor for transmitting torque. A one-way clutch for interrupting power transmission between the crankshaft and a pulley of the crankshaft of the internal combustion engine is provided, wherein the pulley is in operative connection with the electric motor generator and the compressor.

The DE 10 2009 058 133 A1 describes a hybrid vehicle having a powertrain that includes an internal combustion engine, a main electric machine, an auxiliary electric machine, a transmission, and at least one clutch. In order to improve the energy consumption and / or a sportier driving style, the auxiliary electric machine is designed as a starting device for starting the internal combustion engine.

It is an object of the invention to develop a system and a method of the type mentioned so that necessary ancillaries in the vehicle can be operated efficiently in stop phases of the internal combustion engine, especially in a start-stop operation and the system to get more functions.

Disclosure of the invention

According to the invention the object is achieved by the subject matter of claims 1 and 9. The dependent claims define preferred developments.

It is an idea of the invention to develop a system for operating one or more auxiliary units in such a way that with the electric machine, which serves both as a generator and as a motor for at least one ancillary unit, as far as possible also as a starter for the internal combustion engine. Depending on the design, the electric machine can be used as a smaller electrical machine, for example for each warm start of the internal combustion engine. A warm start is defined as the temperature of the engine being greater than a threshold of e.g. 40 ° C and is started at this temperature. A warm start, for example in start-stop operation is when the internal combustion engine is temporarily stopped, for example because of a traffic light stop or a stop on the roadway obstacle. If necessary, especially in gasoline engines and appropriate design, the electric machine could be designed such that in addition a cold start would be possible. The electric machine would thus be redundant next to a conventional starter for the internal combustion engine in the vehicle or it replaces the starter. Furthermore, the start could be quiet and fast.

The object is thus achieved in that the electric machine comprises a shaft having a first shaft portion and a shaft portion, wherein the first shaft portion is engageable with an internal combustion engine and a torque transmitting device in operative connection and the second shaft portion is formed as a drive shaft for a motorized operation of the electric machine for driving at least one auxiliary unit, and with a closable coupling between the first and second shaft portion, with a control with power electronics for a motor and generator operation of the electric machine, wherein the control between a electrical energy storage and the electric machine is switchable, so that the electrical machine is controlled by the controller and the controller can be brought into communication with a parent engine control, can be transferred from the control commands to the controller, wherein the closable clutch from the controller or the engine control is controllable. Thus, the individual small electric machine is not only the task of a generator, but also the function of an electric motor for ancillaries and the ability to start the engine, especially during warm starts in start-stop operation.

The closable coupling thus has a double function. The one function is when the electric machine is used as a drive for at least one auxiliary unit and the mechanical torque transmission device and the internal combustion engine is decoupled. For example, the accessory needs to be powered to provide or maintain certain vehicle conditions or interior conditions, such as cooling the vehicle interior, while simultaneously temporarily stopping the vehicle.

The further function of the closable clutch is to use the electric machine as a starting device to transmit a torque via the torque transmitting device to the output shaft of the internal combustion engine, so that it is started quickly and quietly. Less energy is needed at this start because the electric machine can have kinetic energy if it has been previously used to drive the accessory, which can be included in the starting process.

Advantageously, the first and second shaft sections are formed on an output side of the electric machine with respect to the stator and rotor. This has the advantage that a conventional electric machine can be used without additional conversion measures.

According to an alternative embodiment, the first shaft portion and the second shaft portion are formed with respect to the stator and rotor of the electric machine on opposite sides, wherein the controllable coupling is disposed on the first shaft portion between the torque transmitting device and the rotor. Thus, a conventional electric machine is formed with an extended shaft by a front shaft portion serves as a drive shaft for a regenerative operation or as output shaft for a start function and a rear side shaft portion as output shaft for a motor drive at least one accessory is used. The power flow paths are compared with the construction described above as small as possible in this embodiment.

According to an embodiment further developing the auxiliary unit comprises an air conditioning compressor and / or a steering assist pump and / or a vacuum pump for brake booster and / or one or more water pumps for cooling and / or an oil pump, transmission oil pump and / or a device for condensing fuel. Of course, other ancillaries, which have not been explicitly mentioned here, can be driven if they are necessary for the operation of the vehicle while the internal combustion engine is switched off.

According to a further preferred embodiment, a speed reduction device is arranged between the output shaft section of the electric machine and the auxiliary unit. The speed reducer has the advantage that e.g. high speeds of the output shaft to low speeds for the air compressor are lowered. Thus, by selecting an efficiency-optimal speed with a lower torque of the electric machine, an auxiliary unit can be operated, which requires a higher torque per revolution.

In order to reduce frictional losses when the accessory is not needed, a closable and openable clutch is alternatively or additionally arranged with the speed reducer between the output shaft portion of the electric machine and the second shaft portion for driving the accessory. Thus, further electrical energy or energy of the internal combustion engine is saved, the auxiliary unit should not be needed.

More preferably, the system comprises a start-stop device for the internal combustion engine. Thus, the auxiliary unit is operated independently of stop phases in the start-stop operation of the internal combustion engine and the internal combustion engine is used resource-saving.

In order to operate the accessory adapted to the situation, or to provide so much electrical energy for a warm start of the internal combustion engine by means of the electric machine As required, the electrical power output to the electric machine is controllable during engine operation.

The object is also achieved by a method for operating a, in particular above-described, system with an electric machine, characterized in that the electric machine is driven by an internal combustion engine in a regenerative operation and at least one auxiliary unit of a vehicle, wherein the auxiliary unit in the generator mode of driven by a torque transmitting device of the internal combustion engine and is driven in a motor operating mode of the electric machine thereof, the system having an engine control and a closable clutch between the torque transmitting device and a drive shaft of the electric machine, so that with the torque transmitting device torques on the electric machine are transmitted from the internal combustion engine. The clutch is closed during driving operation of the vehicle for a regenerative operation of the electric machine, as soon as a stop mode of the internal combustion engine is initiated by the engine control in a start-stop operation and the at least one accessory is required in the stop mode to maintain required vehicle conditions in a working mode , the clutch is opened by a control command from the engine control and the electric machine used in engine operation to drive the accessory, wherein the clutch is closed again and the engine is restarted as soon as sufficient electrical energy is provided by an energy storage. A stop mode means that the internal combustion engine has been stopped by the engine control for emission and fuel reduction, because there are corresponding stop conditions, although the driver, the vehicle in total in the operating state by means of a corresponding access means, such. of a key.

This method has the advantage that vehicle conditions, such as the air conditioning of a vehicle, can be maintained even when the internal combustion engine is not in operation, for example due to a start-stop operation. The vehicle is preferably not as a hybrid vehicle, i. formed with an electric drive in the drive train of the vehicle. This method and the system is provided in particular in a conventional vehicle with an internal combustion engine as the only vehicle drive with a start-stop system for the internal combustion engine. A complex powertrain, an internal combustion engine and at least one electric drive machine are not necessary and can be dispensed with.

According to a further preferred embodiment, the internal combustion engine is started by the electric machine via the torque transmission device. Thus, in particular a warm start of both diesel and gasoline internal combustion engines is possible, which under certain circumstances a kinetic energy of the electric machine by closing the closable clutch for starting the internal combustion engine is used. A cold start, i. a start of the internal combustion engine with the temperature below the temperature threshold of about 40 ° C may optionally also be provided with an appropriate design of the internal combustion engine, for example, gasoline instead of diesel engine, and the electric machine.

According to an alternative embodiment, in a warm start, that is to say from a stop mode of a start-stop operation, the engine control unit starts the engine from the electric machine via the torque transmission device, closing the clutch, if not yet in the closed operating state. In this embodiment, a cold start is provided exclusively via the conventional starting device with a separate starter.

According to a further preferred method, the auxiliary unit, in particular an air-conditioning compressor, which is in operative connection with the electric machine, is controlled by the controller. Thus, vehicle interior conditions can be generated more individual and resource-saving.

In another aspect, the invention includes a computer program configured to perform all the steps of any of the foregoing methods.

In a further aspect, the invention comprises a machine-readable storage medium on which this computer program is stored.

In a further aspect, the invention comprises a control device which is set up to carry out all the steps of one of the aforementioned methods

Brief description of the drawings

The invention will be explained in more detail below with reference to drawings. Show it:

1 a schematic arrangement diagram of the system according to the invention according to a first embodiment and

2 a schematic arrangement diagram of the system according to the invention according to a second embodiment.

The 1 shows a schematic arrangement of a system according to the invention 1 with an electric machine 2 , which is designed for both a regenerative and for a motor operation. For a generator operation is via a shaft 3 the electric machine 2 and a torque transmitting device 32 a torque from the internal combustion engine 30 over the pulley 31 and a V-belt 32 on the pulley 13 transfer. For this purpose, a closable coupling 17 between the pulley 13 and a rotor 28 the electric machine 2 on the wave 3 is arranged, closed. The closable coupling 17 is according to the embodiment of 1 from an engine control 10 driven. The engine control 10 can also be a higher-level vehicle control, which includes an unillustrated engine control for operating the internal combustion engine 30 controls.

The wave 3 includes a first shaft portion 4 and a second shaft portion 5 , On the first shaft section 4 is the pulley 13 arranged for torque transmission. A torque is thus for the generator operation via the torque transmission device with the pulley 13 , the V-belt 32 and the pulley 31 used both for the generator operation of the electric machine and for the motor drive according to the invention. In a motor operation, the internal combustion engine 30 redundant to an existing starter or alternatively from the electric machine 2 started.

According to the in 1 shown special embodiment, to small traction paths with respect to the output shafts of the electric machine 2 to generate, that is at least one accessory 27 on the extended shaft 51 that is, on an opposite side of the coupling 17 , concerning a stator 26 and rotor 28 the electric machine 2 arranged. The second wave section 5 is thus located at a rear end of the electric machine 2 when a shaft section 35 with the clutch 17 as the front end of the electric machine 2 referred to as. The accessory 27 , which may also include several ancillaries, such as an air conditioning compressor and / or a steering assist pump and / or a vacuum pump for brake booster and a water pump, may preferably via a speed reduction device 9 are driven. The speed reduction device 9 is from the output shaft 51 of the second shaft section 5 driven.

In one, in the 1 shown, further preferred embodiment is a closable second clutch 29 between speed reduction device 9 and the rotor 28 arranged to friction losses of the speed reduction device 9 and at least one accessory 27 exclude if their operation is not necessary to achieve a vehicle condition. This saves resources. The closable coupling 29 can either from the parent vehicle control or engine control 10 be driven or, as in 1 represented a control 6 , which is also used for control under regulation of the electrical machine 2 is provided. The control 6 serves to feed electrical energy into an energy store 8th and the controlled and regulated supply of electrical energy from the energy storage 8th to the electric machine 2 , By means of the controller 6 is the electrical power output to the electric machine 2 in motor operation so also adjustable. The electric machine 2 can be a DC machine or an AC machine. In the case of an efficient alternator, the controller includes 6 for alternator and motor operation, an AC rectifier that operates in both directions, ie, both AC becomes DC and vice versa DC converts AC. The alternator is controlled in motor operation by means of power electronics. More preferably, the engine control comprises 10 a start-stop device, allowing the internal combustion engine 30 is stopped, for example, at traffic light stops and fuel is saved.

The system 1 uses the following procedure. In a regenerative operation, the clutch is closed 17 and closed clutch 29 both the electric machine 2 via the torque transmission device 32 from the internal combustion engine 30 powered as well as the accessory 27 , Will the accessory 27 not needed, so will the accessory 27 for example, by opening the clutch 29 deactivated, ie temporarily shut down. Will the internal combustion engine 30 stopped in vehicle operation, either by a manual intervention of the driver or for example due to a start-stop device, since the stop conditions of this start-stop device are present, and conditions are detected in the motor vehicle, the operation of the accessory 27 require, so is the closable coupling 17 open and the electric machine 2 in a motorized operation of the controller 6 driven. Here is the electric machine 2 from the controller 6 adjustable. Should the electrical energy in the energy storage 8th fall below a safety level, then the internal combustion engine 30 restarted and the accessory 27 from the internal combustion engine 30 driven, the electric machine 2 returns to the engine mode and the clutch 17 closed again.

According to the invention, the internal combustion engine 30 in a so-called warm start, ie when the engine temperature is above a threshold of eg 40 ° C, by closing the clutch 17 and the motor operation of the electric machine 2 restarted and not a conventional foreseen in the 1 not shown, starter for starting the internal combustion engine 30 used. Thus, the internal combustion engine 30 started quickly and quietly, saving electrical energy resources.

The 2 shows a second particular alternative embodiment of the 1 , The difference in this embodiment over the 1 is only that both the first and second shaft section 4 . 5 on a driven side of the electric machine 2 regarding stator 26 and rotor 28 are formed. It can thus be a conventional electrical machine 2 be used. The accessory 27 is with a speed reduction device 9 , here for example also by means of a belt drive with two pulleys and a V-belt, driven. The closable coupling 17 is between the pulley 13 and the speed reduction device 9 on the wave 3 arranged. The accessory 27 is always driven in this embodiment, when the shaft 3 the electric machine 2 regardless of whether the electric machine is used in generator mode or in motor mode. A separate shutdown of the auxiliary unit 27 is by means of a closable coupling 29 behind the speed reduction device 9 and in front of the accessory 27 possible in its drive train.

All figures show only schematic not to scale representations. In addition, reference is made in particular to the drawings for the invention as essential.

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 10226089 A1 [0004]
• DE 102009058133 A1 [0005]

Claims (15)

System ( 1 ) for operating one or more accessories ( 27 ) of a motor vehicle with an electric machine ( 2 ), which is a wave ( 3 ) with a first shaft section ( 4 ) and a second shaft section ( 5 ), wherein the first shaft section ( 4 ) with an internal combustion engine ( 30 ) is operatively connected via a torque transmitting device and the second shaft portion ( 5 ) as a drive shaft for a motorized operation of the electric machine ( 2 ) for driving the auxiliary unit ( 27 ) is formed, with a closable coupling ( 17 ) between a first and second shaft section ( 4 . 5 ), with a controller ( 6 ) with power electronics for a motor and generator operation of the electrical machine ( 2 ), whereby the controller ( 6 ) between an electrical energy store ( 8th ) and the electric machine ( 2 ) is switchable, so that the electric machine ( 2 ) from the controller ( 6 ) is controllable and controllable, and the controller ( 6 ) in communication contact with a higher-level engine control ( 10 ) can be brought from the control commands to the controller ( 6 ) are transferable, wherein the closable coupling ( 17 ) from the controller ( 6 ) or the engine control ( 10 ) is controllable. System ( 1 ) according to claim 1, characterized in that the first and second shaft sections ( 4 . 5 ) on a driven side of the electric machine ( 2 ) with respect to stator ( 26 ) and rotor ( 28 ) are formed. System ( 1 ) according to claim 1, characterized in that the first shaft section ( 4 ) and the second shaft section ( 5 ) with respect to stator ( 26 ) and rotor ( 28 ) of the electric machine ( 2 ) are formed on opposite sides, wherein the closable coupling ( 17 ) on the first shaft section on the shaft ( 3 ) between the torque transmission device and the rotor ( 26 ) is arranged. System ( 1 ) according to one of the preceding claims, characterized in that the ancillary unit ( 27 ) An air conditioning compressor or a steering assist pump or a vacuum pump for brake booster or one or more water pumps for cooling or an oil pump, transmission oil pump or a device for the condensation of fuel. System ( 1 ) according to claim 4, characterized in that a speed reduction device ( 9 ) between the output shaft section (FIG. 51 ) of the electric machine ( 2 ) and the accessory ( 27 ) is arranged. System ( 1 ) according to claim 5, characterized in that a closable and openable coupling ( 29 ) alternatively or additionally with the speed reduction device ( 9 ) between output shaft section ( 51 ) of the electric machine ( 2 ) and second shaft section ( 5 ) is arranged. System ( 1 ) according to claim 1 to 6, characterized in that the motor vehicle with a start-stop device for the internal combustion engine ( 30 ) is trained. System ( 1 ) according to one of the preceding claims, characterized in that the electrical power output to the electric machine ( 2 ) is controllable in engine operation. Method for operating a system ( 1 ) with an electric machine ( 2 ), by an internal combustion engine ( 30 ) is driven in a generator operation, with at least one accessory ( 27 ) of a vehicle, wherein the accessory ( 27 ) in regenerative operation of the electric machine ( 2 ) via a torque transmission device of the internal combustion engine ( 30 ) and wherein the ancillary unit ( 27 ) with the internal combustion engine of the electric machine ( 2 ) is driven in a motor operating mode, with an engine control ( 10 ) and a closable coupling ( 17 ) between the torque transmission device ( 32 ) and a drive shaft ( 31 ) of the electric machine ( 2 ), wherein with the torque transmission device ( 32 ) Torques on the electric machine ( 2 ) of the internal combustion engine ( 30 ), whereby the coupling ( 17 ) while driving the vehicle for a regenerative operation of the electric machine ( 2 ) is closed as soon as a stop mode of the internal combustion engine ( 30 ) of the engine control ( 10 ) is initiated during vehicle operation and the at least one auxiliary unit ( 17 ) is required in stop mode to maintain required vehicle conditions in a working mode, the clutch ( 17 ) by a control command from the engine control ( 10 ) and the electric machine ( 2 ) in motor operation for driving the auxiliary unit ( 27 ) is used, wherein the coupling ( 17 ) is closed again and the internal combustion engine ( 30 ) is restarted as soon as sufficient electrical energy from an energy store ( 8th ) is made available. Method according to claim 9, characterized in that the internal combustion engine ( 30 ) of the electric machine ( 2 ) via the torque transmission device ( 32 ) is started, the clutch ( 17 ) is closed. A method according to claim 9, characterized in that in a warm start, that is from a stop mode of a start-stop operation, of the engine control ( 10 ) the internal combustion engine ( 30 ) of the electric machine ( 2 ) via the torque transmission device ( 32 ) is started, wherein the clutch, if not yet transferred to the closed state, is closed. Method according to claim 9, 10 or 11, characterized in that the ancillary unit ( 27 ) from the controller ( 6 ) is regulated. Computer program adapted to carry out all steps of the method according to one of the claims 9-12. A machine readable storage medium storing the computer program of claim 13. Control device adapted to carry out all the steps of the method according to one of Claims 9-12.

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