DE3539782A1 - Turbocharger system - Google Patents

Abstract

In a turbocharger system for an internal combustion engine with a turbine arranged in the exhaust port of the internal combustion engine and a compressor arranged in the intake port, the turbine and the compressor being coupled to one another to form a turbocharger, the turbocharger is coupled to an electrical generator. The electrical generator can be controlled by a control device in such a way that it feeds power to, or draws it from, the turbocharger as a function of the respective operating state of the internal combustion engine. This permits an improvement, in particular, of the dynamic behaviour of the internal combustion engine.

Description

The invention relates to a turbocharger system for a Internal combustion engine with one in the exhaust duct of the internal combustion engine engine arranged turbine and one in the on Suction channel arranged compressor, the turbine and the compressor to a turbocharger with each other are coupled. The invention further relates on procedures for operating the turbocharger system.

To increase the performance of internal combustion engines is a pre-compression of the combustion gases or known to the air. The pre-compression, also called charging, with the help of a Compressor (loader, charge pump) made for what different types of drives have become known are.

So are arrangements for mechanical coupling of the Compressor with the crankshaft of the internal combustion engine ne became known, which has the advantage of a have simple mechanical structure and also by  the rigid coupling has good dynamic behavior show, so that such engines hang well on the gas and a high torque even at low speeds ment. The low stands for these advantages Overall efficiency of a mechanically charged one Internal combustion engine opposite.

Other known arrangements use the ent in the exhaust gas holding energy to drive the compressor. This has almost exclusively the exhaust gas turbo loader enforced, in which the engine exhaust gases Drive the turbine with which the compressor over a common shaft is coupled. This thermo dynamic coupling of the turbocharger with the Brenn engine leads to sudden changes of the load state, such as when Accelerate the compressor speed and thus the Boost pressure lags behind demand. The cause of this is on the one hand in the default from accelerating to Building up a sufficiently large and hot amount of exhaust gas; on the other hand, a considerable part of the output from the exhaust gas to the turbine Acceleration of the turbine wheel, the shaft and the Compressor wheel are used.

Another disadvantage of the turbocharger is that interventions to regulate the operating state of the Turbochargers are only possible to a limited extent.

The object of the present invention is known To improve turbochargers and especially the adaptations solution of the turbocharger to different operating conditions to enable the internal combustion engine.  

The turbocharger system according to the invention is thereby characterized in that the turbocharger with an electric machine is coupled. Further training of the inventor Invention turbocharger system is that the electric machine from a control device of the Art is controllable that depending on the respective current operating state of the internal combustion engine the door bolader supplies or removes energy. Through this inventive design of the turbocharger system will adjust the performance of the turbocharger different operating states of the internal combustion engine enables. Especially the dynamic behavior can be improved. Possibly. can also do that at known turbochargers bridging the turbine Wastegate is eliminated, which simplifies the Exhaust duct and the silencer is possible.

There are further refinements of the invention in that the electric machine via the Steuereinrich device is connected to an energy store, wel chem the energy supplied to the turbocharger or which is the energy taken from the turbocharger gie is supplied. The turbocharger withdrawn energy for charging the energy storage be used or when the battery is fully charged Energy storage can be converted into heat.

In a further embodiment of the invention the energy storage the battery of the vehicle, in which the internal combustion engine is arranged. Here can such an interpretation take place that more electrical energy is generated as is consumed and that the difference to supply the rest of the consumption cher of the vehicle is sufficient.  

A particularly simple design of the invention be is that the turbine, the compressor and the Electric machine arranged on a common shaft are not.

The turbocharger system according to the invention can Set of sensors with which each Operating state of the internal combustion engine is detected. This makes various advantageous methods for operating the turbocharger system according to the invention enables.

Such a development of the invention exists in that the control device with a speed Sensor and a throttle sensor connected is. A method of operating this turbocharger Stems is characterized in that the Steuerein Direction signals are supplied, which the throttle flap position and the speed of the internal combustion engine play back and that the control device regulates the electric machine in such a way that with sudden chem opening the throttle valve the electric machine accelerates the compressor and in case of sudden Close the throttle valve to the electric machine Compressor brakes.

This procedure ensures that the lei of the internal combustion engine in the event of sudden gas ben is quickly increased and that in case of sudden Throttle valve closing at high turbocharger Speed no pressure peaks occur in the intake duct Ten. This so-called pumping in known Turbocharger systems a dangerous additional Be load for the turbocharger and can also Cause damage to the injection system. They are  to avoid pumping in the known turbola measures to bridge the compression ters known with the help of a valve, which by controlled the negative pressure behind the throttle valve becomes. However, these known measures are construct tiv quite complex.

To the default between suddenly accelerating and Accelerating the compressor with known turbola Keeping the systems as small as possible are known Turbocharger in the exhaust duct as close as possible to the Internal combustion engine arranged, which is a high loading driving temperature of the turbine. By appropriate design, especially material choice is the door in known turbocharger systems bine designed for this. In the invention Turbocharger system is the distance between the turbine and internal combustion engine not so critical in terms of to the above-mentioned default and can therefore ever chosen larger from a design point of view will.

Another method according to the invention is thereby characterized in that a target value for the boost pressure from the speed and the throttle valve position is formed that the target value of the boost pressure with compared the actual value and the result of Ver at the same time via a partially as a differential controller trained controller supplied to a power level becomes.

Another embodiment of the Ver driving is that the idle speed by evaluating the signal from the speed sensor and control of the boost pressure using the control unit  direction and the electric machine is regulated if the throttle valve is in the idle position det.

Other opportunities are provided by inclusion a temperature sensor for the charge air into which he Turbocharger system according to the invention opened. That's the way it is for example possible by evaluating the signal of the temperature sensor and control of the boost pressure with the help of the control device and the electroma seem to limit the boost pressure depending on the temperature Zen. In addition, by evaluating the signal of the Speed sensor the operating status of a start the internal combustion engine can be recognized and by off evaluation of the signal of the temperature sensor for the Charge air is differentiated between warm and cold start be, so that depending on it in itself known control of the internal combustion engine done during the startup process.

The connection of a knock sensor to the fiction moderate turbocharger system enables further processes to operate the turbocharger system. One of these ver driving is characterized in that when it occurs by knocking the operating conditions of the internal combustion engine machine (for example boost pressure, speed) in one non-volatile memory can be written that the internal combustion engine from the control device in an operating area in which no Knock occurs, passing from time to time the stored operating conditions Limit is exceeded, and that when Knock the operating conditions then present get saved. Due to the substantial size The temperature and pressure loads are charged  Motors stronger than naturally aspirated engines due to knocking Ver burning at risk. This further training of the inventor The method according to the invention enables a load of the engine close to the knock limit, one being self active adaptation to different fuel quality ten.

To react as quickly as possible when knocking occurs Being able to greed is a further training this procedure until the boost pressure takes effect regulation the pre-ignition is withdrawn.

In addition, from the occurrence of Knock stored operating conditions a measure calculated and displayed for the fuel quality be, which is not an absolute measure needs to act, just a change display of the previously used fuel. The changes then become such a display the operating conditions encountered when knocking evaluated.

Finally, the control device of the invent turbocharger system according to the invention with one in the exhaust gas nal of the internal combustion engine arranged lambda probe be connected so that the boost pressure depending is controlled by the signal from the lambda sensor.

The invention allows numerous embodiments. Two of these are shown schematically in the drawing shown several figures and below be wrote. It shows:  

Fig. 1 is a schematic representation of an example and Ausfüh

Fig. 2 is a flowchart of a program stored in the microcomputer.

The turbine 1 , the electric machine 2 and the compression ter 3 are arranged on a common shaft 4 . The turbine is located in the exhaust duct 5 of an internal combustion engine 6 , hereinafter referred to as the engine. On the outlet side, the turbine 1 is connected to a silencer 7 . The compressor 3 is connected on the inlet side to an air filter 8 and connected to the intake duct 10 of the engine 6 via a charge air cooler 9 . In the intake duct 10 there is a throttle valve arrangement 11 . Furthermore, a fuel injection system 12 is assigned to the intake duct 10 , which is connected via fuel lines 13 , 14 , 15 , 16 to an injection valve arranged in the engine 6 , not shown in the figure.

Finally, the engine 6 is also assigned an ignition system 17 , in which a high-voltage stage 18 is connected to spark plugs 23 , 24 , 25 , 26 via lines 19 , 20 , 21 , 22 . The ignition system 17 are supplied by corresponding sensors 27 , 28 , which are connected to the crankshaft, not shown, a pulse sensor signal and a signal for identifying the top dead center.

The electric machine 2 is connected to the battery 32 via a Lei stungsstufe 31 contained in the control device 30 such that from the electric machine 2 of the battery 32 energy can be supplied or the battery 32 energy for the electric machine 2 can be removed. The energy supply or withdrawal can be steplessly controlled, so that the case is also possible in which the electric machine 2 is neither removed nor supplied with energy. A microcomputer 33 contained in the control device 30 controls the power stage 31 as a function of various operating states of the engine 6 according to a program stored in the microcomputer 33 . Various data, for example the engine map and the octane number of the fuel used, are stored in a non-volatile read / write memory 34 .

To detect the operating state of the engine 6 who the control device 30 from various sen sensors measured quantities. Thus, with the help of a throttle valve potentiometer 35, a voltage corresponding to the throttle valve position of the control device 30 is supplied. A charge air temperature sensor 36 conducts a voltage analogous to the air temperature in the intake duct to the control device 30 . Furthermore, a charge pressure sensor 37 is provided in the control device 30 , which is connected to the intake duct 10 via a pipeline 38 . If necessary, it is also possible to arrange the boost pressure sensor 37 directly on the intake duct 10 and connect it to the control device 30 via an electrical line. For the measured values supplied as an analog quantity to the control device 30, analog / digital converters 39 , 40 , 41 are provided in the control device. For further detection of the operating state of the engine 6 , a button sensor 42 is arranged on the engine, the output signal of which is converted in the control device 30 with the aid of an input filter 43 into a binary signal to be supplied to the microcomputer 33 . Furthermore, the control device 30 is supplied with a speed signal from the ignition system 17 via an input stage 44 .

With the control device 30 , the ignition timing can also be adjusted, for which purpose the Steuereinrich device 30 is provided with a control stage 45 , which is connected to the ignition system 17 . Finally, the fuel quantity of the control device 30 can be influenced, for which purpose a control stage 46 is connected to the fuel injection system 12 .

In the explanation of the function of the arrangement shown in FIG. 1 Darge, reference is first made to the function of the known turbocharger systems. The hot exhaust gases emitted by the engine 6 are fed to the turbine 1 via the exhaust gas duct 5 , drive the turbine wheel there and escape to the outside via the silencer. The turbine 1 drives a compressor 3 via a shaft 4 , which draws in the charge air from the engine 6 from the environment via the air filter 8 and condenses it into the intake duct 10 . Since the charge air heats up due to the compression, a charge air cooler 9 is seen in the most common turbocharger systems. Via a throttle valve assembly 11, the charge air reaches the engine, where, with the aid of the injection system 12 , which is connected via the lines 13 , 14 , 15 , 16 to injection valves (not shown), the mixture is prepared. Whether a direct injection system is shown in the embodiment, the invention can also be applied together with a central injection system.

In the known turbocharger systems, a delay occurs after opening the throttle valve 11 , because a certain time elapses until the engine produces a sufficiently large amount of hot exhaust gases and until the resulting pressure wave has reached the exhaust gas duct 1 through the gas duct 5 . Furthermore, part of the energy of the hot exhaust gas is initially needed to accelerate the turbine wheel and the compressor wheel until the boost pressure finally rises.

If the throttle valve 11 suddenly closes, there is also a control delay, which has the effect that an excessive boost pressure occurs in the intake duct 10 in front of the throttle valve. This so-called pumping represents a dangerous additional load for the turbocharger and can also lead to damage to the injection system. The known turbocharger systems also have disadvantages in stationary operation. For example, the boost pressure is strongly speed-dependent, which, without further measures, means that either the boost pressure is too low at low speeds or the boost pressure is too high at high speeds.

In known turbocharger systems, mechanical control devices are therefore provided, such as bridging the turbine 1 with the aid of a so-called wastegate or to prevent pumping, the bridging of the compressor with a likewise controllable valve. However, these valves cannot fundamentally improve the dynamic behavior. Finally, a wastegate in the exhaust duct cancels the inherently sound-absorbing effect of the turbine, so that the subsequent silencer becomes more complex than with an engine with a turbocharger, but without a wastegate.

In the illustrated embodiment of the inven tion, the turbine 1 and the compressor 3 are now popped via the shaft 4 with an electric machine 2 . The electric machine 2 is connected via a power stage 31 to a battery 32 . The Lei stungsstufe 31 can now be controlled by the microcomputer 33 such that the electric machine 2 delivers electrical energy to the battery 32 , ie works as a generator or that the electric machine 2 works as a motor, whereby it receives energy from the battery 32 . The control is practically stepless. If no intervention in the turbocharger system is necessary, the power stage 31 is in its “zero position”, the electric machine 2 being practically separated from the battery. Such power levels are known, for example in electric vehicles, and do not need to be described in more detail to explain the invention.

A non-volatile read-write memory for the engine map and the octane number of the fuel is now assigned to the microcomputer 33 . The non-volatile memory can be, for example, an NVRAM or an EEPROM.

The function of the microcomputer 33 and the parts of the arrangement of FIG. 1 connected to it are explained using the example of a so-called knock control in the fol lowing with reference to the flow diagram shown in FIG .

The program is started at 51 and reads in 52 the contents of the non-volatile memory into the working memory. Thereafter, a counting variable k is set in program part 53 to an initial value n , which indicates after how many program runs should be attempted in the case of non-knocking combustion, whether knocking combustion takes place when a map value increases.

Then the operating point is read in the program part 54 , which is essentially formed from the engine speed and the throttle valve position. The signal from the knock sensor is read in at 55 and a decision is made at 56 whether there is a knocking combustion. If there is a knocking combustion, the map value read from the non-volatile memory is reduced at 57 and the power stage 31 ( FIG. 1) is controlled accordingly. Furthermore, the old map value is replaced by the new map value at 58 in the working memory, after which the program is returned to point 59 .

However, if no knocking combustion is found at 56 , the program branches at 60 depending on whether the engine is running or not. If the engine is not running, it has been switched off after one operation, the content of the main memory is copied into the non-volatile memory with the aid of the program part 61 and the program is ended at 62 .

With the engine running and combustion not knocking, the counting variable k is reduced by 1 at 63 and the program continues as long as k is not = 0 via the branch 64 at 65 . If the count variable k has reached zero value 0, the map value is tentatively increased in the program part 66 , the increased value is written into the working memory at 58 and the program is operated with the increased map value until control begins.

Claims (24)

1. Turbocharger system for an internal combustion engine with a turbine arranged in the exhaust gas duct of the internal combustion engine and a compressor arranged in the intake duct, the turbine and the compressor being coupled to one another to form a turbocharger, characterized in that the turbocharger ( 1 , 3 ) is connected to an electric machine ( 2 ) is coupled. 2. Turbocharger system according to claim 1, characterized in that the electric machine ( 2 ) can be controlled by a control device ( 30 ) such that it supplies or takes energy from the turbocharger ( 1 , 3 ) as a function of the respective operating state of the internal combustion engine ( 6 ) . 3. Turbocharger system according to claim 1, characterized in that the electric machine ( 2 ) via the control ereinrichtung ( 30 ) is connected to an energy store ( 32 ), from which the turbocharger ( 1 , 3 ) to be taken energy is removed. 4. Turbocharger system according to claim 3, characterized in that the energy store ( 32 ) the turbocharger ( 1 , 3 ) withdrawn energy is supplied. 5. Turbocharger system according to claim 4, characterized in that a switching device is provided which, when the energy storage device ( 32 ) is fully charged, switches on a device for converting the electrical energy generated by the electrical machine ( 2 ) into heat. 6. Turbocharger system according to claim 3, characterized in that the energy store ( 32 ) is the battery of a vehicle in which the internal combustion engine ( 6 ) is arranged. 7. turbocharger system according to claim 6, characterized by such a design that more electrical Energy generated than is consumed and that the dif reference to supply the other consumers of the Vehicle is sufficient. 8. Turbocharger system according to claim 1, characterized in that the turbine ( 1 ), the compressor ( 3 ) and the electric machine ( 2 ) are arranged on a common shaft ( 4 ). 9. Turbocharger system according to claim 2, characterized in that the control device ( 30 ) with a speed sensor ( 27 ) and a throttle valve position sensor ( 35 ) is connected. 10. Procedure for operating the turbocharger system according to Claim 9, characterized in that the tax device signals are supplied which the Throttle valve position and the speed of the combustion Play engine and that the Steuereinrich tion regulates the electric machine so that at suddenly opening the throttle valve the electroma seems the compressor accelerates and in the event of a sudden closing the throttle valve the electroma seems to slow down the compressor. 11. The method according to claim 10, characterized in net that a target value for the boost pressure from the Speed and the throttle valve position formed is that the target value of the boost pressure with the actual Value compared and the result of the comparison over a partially designed as a differential controller Controller is supplied to a power level. 12. Procedure for operating the turbocharger system according to Claim 9, characterized in that the idle speed by evaluating the signal of the speed Sensor and control of the boost pressure using the Control device and the electric machine regulated will when the throttle valve is idling position. 13. Procedure for operating the turbocharger system according to Claim 9, characterized in that the Dros Selklappe a signal to indicate full throttle position is derived and that if the ses signal the boost pressure is increased.   14. Turbocharger system according to claim 2, characterized ge indicates that a temperature sensor for the Charge air is connected to the control device. 15. Procedure for operating the turbocharger system according to Claim 14, characterized in that by Aus evaluation of the signal of the temperature sensor and control tion of the boost pressure with the help of the control device and the electric machine the boost pressure temperature is limited. 16. Procedure for operating the turbocharger system according to Claim 14, characterized in that by Aus Evaluation of the signal from the speed sensor of the loading drive state at a start of the internal combustion engine is recognized and by evaluating the signal of the Temperature sensor between warm and cold start under will be separated and that depending on it in is known to control the internal combustion engine machine takes place during the starting process. 17. Turbocharger system according to claim 7, characterized in that the control device ( 30 ) is connected to a knock sensor ( 42 ). 18. Procedure for operating the turbocharger system according to Claim 17, characterized in that when it occurs the operating conditions of the burner engine (for example boost pressure, speed) written into a non-volatile memory be that the engine from the Steuerein direction is kept in an operating area in who does not experience knocking from time to time which are determined by the stored operating conditions set limit is exceeded, and that at Auf  tapping the then available operational areas conditions are saved. 19. The method according to claim 18, characterized in net that when knock occurs to boost pressure regulation of the electric machine to the turbocharger energy takes. 20. The method according to claim 19, characterized in net that when knocking occurs also the pre-ignition until the boost pressure control takes effect is withdrawn. 21. The method according to claim 18, characterized in net that from the stored Betriebsbe a measure of fuel quality net and is displayed. 22. The method according to claim 18, characterized in net that from the change in the stored Be drive conditions a measure of the change in force fabric quality is calculated and displayed. 23. Turbocharger system according to claim 2, characterized in that the control device ( 30 ) is connected to a lambda probe arranged in the exhaust duct ( 5 ) of the internal combustion engine ( 6 ). 24. Procedure for operating the turbocharger system according to Claim 23, characterized in that the drawer pressure depending on the signal from the lambda sensor is controlled.